Powered by Deep Web Technologies
Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

HERSCHEL OBSERVATIONS OF CATACLYSMIC VARIABLES  

SciTech Connect (OSTI)

We have used the PACS instrument on the Herschel Space Observatory to observe eight cataclysmic variables at 70 and 160 {mu}m. Of these eight objects, only AM Her was detected. We have combined the Herschel results with ground-based, Spitzer, and WISE observations to construct spectral energy distributions for all of the targets. For the two dwarf novae in the sample, SS Cyg and U Gem, we find that their infrared luminosities are completely dominated by their secondary stars. For the two highly magnetic 'polars' in our survey, AM Her and EF Eri, we find that their mid-infrared excesses, previously attributed to circumbinary dust emission, can be fully explained by cyclotron emission. The WISE light curves for both sources show large, orbitally modulated variations that are identically phased to their near-IR light curves. We propose that significant emission from the lowest cyclotron harmonics (n {<=} 3) is present in EF Eri and AM Her. Previously, such emission would have been presumed to be optically thick, and not provide significant orbitally modulated flux. This suggests that the accretion onto polars is more complicated than assumed in the simple models developed for these two sources. We develop a model for the near-/mid-IR light curves for WZ Sge with an L2 donor star that shows that the ellipsoidal variations from its secondary star are detected. We conclude that none of the targets surveyed have dusty circumbinary disks.

Harrison, Thomas E.; Hamilton, Ryan T. [Department of Astronomy, New Mexico State University, Box 30001, MSC 4500, Las Cruces, NM 88003-8001 (United States); Tappert, Claus [Departamento de Fisica y Astronomia, Universidad de Valparaiso, Avda. Gran Bretana 1111, Valparaiso (Chile); Hoffman, Douglas I. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Campbell, Ryan K., E-mail: tharriso@nmsu.edu, E-mail: rthamilt@nmsu.edu, E-mail: claus.tappert@uv.cl, E-mail: dhoffman@ipac.caltech.edu, E-mail: Ryan.Campbell@humobldt.edu [Department of Physics and Astronomy, Humboldt State University, 1 Harpst St., Arcata, CA 95521 (United States)

2013-01-01T23:59:59.000Z

2

Tropical climate variability from the last glacial maximum to the present  

E-Print Network [OSTI]

This thesis evaluates the nature and magnitude of tropical climate variability from the Last Glacial Maximum to the present. The temporal variability of two specific tropical climate phenomena is examined. The first is the ...

Dahl, Kristina Ariel

2005-01-01T23:59:59.000Z

3

EXTENSION OF THE MAXIMUM POWER REGION OF DOUBLY-SALIENT VARIABLE RELUCTANCE MOTORS  

E-Print Network [OSTI]

-Salient Variable Reluctance Motors (DSVRM) has been investigated and developed for variable-speed drives during, variable-frequency generators, wind wheels, machine tools, etc.). In these applications, it is generally necessary to operate in a regime of a high speed ux-weakening (zone of maximum constant power), for a better

Paris-Sud XI, Université de

4

Variable Selection for Modeling the Absolute Magnitude at Maximum of Type Ia Supernovae  

E-Print Network [OSTI]

We discuss what is an appropriate set of explanatory variables in order to predict the absolute magnitude at the maximum of Type Ia supernovae. In order to have a good prediction, the error for future data, which is called the "generalization error," should be small. We use cross-validation in order to control the generalization error and LASSO-type estimator in order to choose the set of variables. This approach can be used even in the case that the number of samples is smaller than the number of candidate variables. We studied the Berkeley supernova database with our approach. Candidates of the explanatory variables include normalized spectral data, variables about lines, and previously proposed flux-ratios, as well as the color and light-curve widths. As a result, we confirmed the past understanding about Type Ia supernova: i) The absolute magnitude at maximum depends on the color and light-curve width. ii) The light-curve width depends on the strength of Si II. Recent studies have suggested to add more va...

Uemura, Makoto; Kawabata, S; Ikeda, Shiro; Maeda, Keiichi

2015-01-01T23:59:59.000Z

5

Period-luminosity and period-luminosity-colour relations for Mira variables at maximum light  

E-Print Network [OSTI]

In this paper we confirm the existence of period-luminosity (PL) and period-luminosity-colour (PLC) relations at maximum light for O and C Mira variables in the LMC. We demonstrate that in the J and H bands the maximum light PL relations have a significantly smaller dispersion than their counterparts at mean light, while the K band and bolometric PL relations have a dispersion comparable to that at mean light. In the J, H and K bands the fitted PL relations for the O Miras are found to have smaller dispersion than those for the C Miras, at both mean and maximum light, while the converse is true for the relations based on bolometric magnitudes. The inclusion of a non-zero log period term is found to be highly significant in all cases except that of the C Miras in the J band, for which the data are found to be consistent with having constant absolute magnitude. This suggests the possibility of employing C Miras as standard candles. We suggest both a theoretical justification for the existence of Mira PL relations at maximum light and a possible explanation of why these relations should have a smaller dispersion than at mean light. The existence of such maximum light relations offers the possibility of extending the range and improving the accuracy of the Mira distance scale to Galactic globular clusters and to other galaxies.

S. M. Kanbur; M. A. Hendry; D. Clarke

1997-04-14T23:59:59.000Z

6

8) Stratospheric equatorial variability a) Observations  

E-Print Network [OSTI]

speed. Phase lines inclined eastward when altitude increases indicating upward propation Signal field) Westward phase propagation but eastward group propagation Phase lines inclined westward Signal;5 Satellites wind observations (UARS, Swinbak et Ortland 1997) The Quasi-Biennial Oscillation (low stratosphere

Lott, Francois

7

Dynamics and variability of the plasmasphere observed from synchronous orbit  

SciTech Connect (OSTI)

The behavior of the cold ions in the outer plasmasphere is studied using data obtained with the magnetospheric plasma analyzers from multiple geosynchronous satellites. Dense (10-100 cm{sup {minus}3}), cold ({approx}1 eV) regions of plasma are often observed at geosynchronous orbit; in this study the authors refer to these as plasmaspheric intervals. The duration, local time of observation, density variability, and temperature behavior within these regions often depend in a systematic way on geomagnetic and substorm activity. With increasing geomagnetic activity (as indicated by Kp) the plasmaspheric regions are generally observed over shorter durations and at earlier local times. With increasing substorm activity (as indicated by geosynchronous energetic electron injections) the density becomes increasingly variable in these regions. Occasionally, up to order-of-magnitude density variations are observed over several minute timescales corresponding to regions with physical dimensions on the order of 1000 km or less. The appearance of these short-duration, cold-plasma intervals is strongly correlated with energetic ion and electron signatures both at the spacecraft making the plasmaspheric observations and at other spacecraft observing simultaneously in the midnight region. Such energetic particle signatures are indicative of the growth and expansive phase of geomagnetic substorms. The authors conclude that the appearance of these short-duration, plasmaspheric intervals is due to a reconfiguration of the duskside magnetosphere during geomagnetic substorms.

Moldwin, M.B.; Thomsen, M.F.; McComas, D.J.; Reeves, G.D.

1994-11-01T23:59:59.000Z

8

Observational Constraints of New Variable Modified Chaplygin Gas Model  

E-Print Network [OSTI]

Assuming the flat FRW universe in Einstein's gravity filled with New Variable Modified Chaplygin gas (NVMCG) dark energy and dark matter having negligible pressure. In this research work we analyze the viability on the basis of recent observation. Hubble parameter $H$ is expressed in terms of the observable parameters $H_0$, $\\Omega_m^0$ and the model parameters $A_0$, $B_0$, $C_0$, $m$, $n$, $\\alpha$ and the red shift parameter $z$. Here we find a best fitted parameter range of $A_0$, $B_0$ keeping $0\\leq \\alpha \\leq 1$ and using Stern data set (12 points) by minimizing the $\\chi^2$ test at 66%, 90% and 99% confidence levels. Next we do the joint analysis with BAO and CMB observations. Again evaluating the distance modulus $\\mu(z)$ vs redshift ($z$) curve obtained in the model NVMCG with dark matter with the best fitted value of the parameters and comparing with that derived from the union2 compilation data.

Jhumpa Bhadra; Ujjal Debnath

2012-11-09T23:59:59.000Z

9

OBSERVATIONS OF THERMAL FLARE PLASMA WITH THE EUV VARIABILITY EXPERIMENT  

SciTech Connect (OSTI)

One of the defining characteristics of a solar flare is the impulsive formation of very high temperature plasma. The properties of the thermal emission are not well understood, however, and the analysis of solar flare observations is often predicated on the assumption that the flare plasma is isothermal. The EUV Variability Experiment (EVE) on the Solar Dynamics Observatory provides spectrally resolved observations of emission lines that span a wide range of temperatures (e.g., Fe XV-Fe XXIV) and allow for thermal flare plasma to be studied in detail. In this paper we describe a method for computing the differential emission measure distribution in a flare using EVE observations and apply it to several representative events. We find that in all phases of the flare the differential emission measure distribution is broad. Comparisons of EVE spectra with calculations based on parameters derived from the Geostationary Operational Environmental Satellites soft X-ray fluxes indicate that the isothermal approximation is generally a poor representation of the thermal structure of a flare.

Warren, Harry P.; Doschek, George A. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Mariska, John T. [School of Physics, Astronomy, and Computational Sciences, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States)

2013-06-20T23:59:59.000Z

10

Lack of uniform trends but increasing spatial variability in observed Indian rainfall extremes  

SciTech Connect (OSTI)

Recent studies disagree on how rainfall extremes over India have changed in space and time over the past half century, as well as on whether the changes observed are due to global warming or regional urbanization. Although a uniform and consistent decrease in moderate rainfall has been reported, a lack of agreement about trends in heavy rainfall may be due in part to differences in the characterization and spatial averaging of extremes. Here we use extreme value theory to examine trends in Indian rainfall over the past half century in the context of long-term, low-frequency variability.We show that when generalized extreme value theory is applied to annual maximum rainfall over India, no statistically significant spatially uniform trends are observed, in agreement with previous studies using different approaches. Furthermore, our space time regression analysis of the return levels points to increasing spatial variability of rainfall extremes over India. Our findings highlight the need for systematic examination of global versus regional drivers of trends in Indian rainfall extremes, and may help to inform flood hazard preparedness and water resource management in the region.

Ghosh, Subimal [ORNL; Das, Debasish [ORNL; Kao, Shih-Chieh [ORNL; Ganguly, Auroop R [ORNL

2012-01-01T23:59:59.000Z

11

Optimization of the transmission of observable expectation values and observable statistics in Continuous Variable Teleportation  

E-Print Network [OSTI]

We analyze the statistics of observables in continuous variable quantum teleportation in the formalism of the characteristic function. We derive expressions for average values of output state observables in particular cumulants which are additive in terms of the input state and the resource of teleportation. Working with Squeezed Bell-like states, which may be optimized in a free parameter for better teleportation performance we discuss the relation between resources optimal for fidelity and for different observable averages. We obtain the values of the free parameter which optimize the central momenta and cumulants up to fourth order. For the cumulants the distortion between in and out states due to teleportation depends only on the resource. We obtain optimal parameters for the second and fourth order cumulants which do not depend on the squeezing of the resource. The second order central momenta which is equal to the second order cumulants and the photon number average are optimized by the same resource. We show that the optimal fidelity resource, found in reference (Phys. Rev. A {\\bf 76}, 022301 (2007)) to depend also on the characteristics of input, tends for high squeezing to the resource which optimizes the second order momenta. A similar behavior is obtained for the resource which optimizes the photon statistics which is treated here using the sum of the squared differences in photon probabilities of input and output states as the distortion measure. This is interpreted to mean that the distortions associated to second order momenta dominates the behavior of the output state for large squeezing of the resource. Optimal fidelity and optimal photon statistics resources are compared and is shown that for mixtures of Fock states they are equivalent.

L. Albano Farias; J. Stephany

2010-09-28T23:59:59.000Z

12

Observer Variability in Metameric Color Matches using Color  

E-Print Network [OSTI]

* Correspondence to: R. L. Alfvin, Eastman Kodak Company, Build- to another observer. This phenomenon is caused by ob- ing 65, Rochester, NY 14650-1829 server metamerism. Contract grant sponsor: NSF-NYS

Fairchild, Mark D.

13

X-ray and optical variability of Seyfert 1 galaxies as observed with XMM-Newton  

E-Print Network [OSTI]

We have examined simultaneous X-ray and optical light curves of a sample of eight nearby Seyfert 1 galaxies observed using the EPIC X-ray cameras and Optical Monitor on board XMM. The observations span ~1 day and revealed optical variability in four of the eight objects studied. In all cases, the X-ray variability amplitude exceeded that of the optical both in fractional and absolute luminosity terms. No clearly significant correlations were detected between wavebands using cross correlation analysis. We conclude that, in three of the four objects in which optical variability was detected, reprocessing mechanisms between wavebands do not dominate either the optical or X-ray variability on the time-scales probed.

R. Smith; S. Vaughan

2007-01-08T23:59:59.000Z

14

Development of a weighted-average estimator from a maximum-likelihood estimator and an instrumental-variable estimator in a structural model  

E-Print Network [OSTI]

, is written as mx y Ab Sou 1hl zz mx x ? Ab?' S?? (3. 2) and we will now spend some time explaining its form. Write a = (1, ? P&) and assume an independent estimator of Z, S?, is avail- able. Fuller (1981) shows that maximizing the likelihood equations... ? z, + u? t = 1, 2, . . . , a?s' = 1, 2, 3, . . . , b? (2. 1c) The total number of observations, n, is equal to a?b?. The experimenter has available an instrumental variable for the unobservable ze =&a+sr&W, +re, t=1, 2, . . . , a?. (2. 1d...

Gruben, David Christopher

1987-01-01T23:59:59.000Z

15

Determination of the Hubble constant from observations of Cepheid variables in the galaxy M96  

E-Print Network [OSTI]

New Hubble Space Telescope observations of Cepheid variable stars in the nearby galaxy M96 give a distance to the host galaxy group, Leo-I, of 11.6+/-0.8 Mpc. This value, used in conjunction with several reliable secondary indicators of relative distance, constrains the distances to more remote galaxy clusters, and yields a value of the Hubble constant (Ho=69+/-8 km/s/Mpc) that is independent of the velocity of the Leo-I group itself.

N. R. Tanvir; T. Shanks; H. C. Ferguson; D. R. T. Robinson

1995-10-01T23:59:59.000Z

16

Multiwavelength Observations of GX 339-4 in 1996. II. Rapid X-ray Variability  

E-Print Network [OSTI]

As part of our multiwavelength campaign of GX 339-4 observations in 1996 we present the rapid X-ray variability observed July 26 using the RXTE when the source was in a hard state (= soft X-ray low state). We found that the source was extremely variable, with many bright flares. The flares have relatively symmetric time profiles. There are a few time intervals where the flux rises steadily and then drops suddenly, sometimes to a level lower than the average before the increase. Hardness ratios showed that the source was slightly softer when the flux was brighter. The power density spectra (PDS) were also complicated and we found that broken power laws do not provide adequate fits to any of them. Instead a pair of zero-centered Lorentzians gives a good general description of the shape of the PDS. We found several quasi-periodic oscillations (QPO), including some that are harmonically spaced with the most stable frequency at 0.35 Hz. While the overall rms variability of the source was close to being constant throughout the observation (29% integrating between 0.01 and 50 Hz), there is a small but significant change in the PDS shape with time. More importantly, we show that the soft 2-5 keV band is more variable than the harder 5-10 and 10-40 keV bands, which is unusual for this source and for other black hole candidates. Cross correlation functions (CCF) between these bands show that the light curve for the 10-40 keV band lags that of the 2-5 keV band by 5 msec.

I. A. Smith; E. P. Liang

1998-12-08T23:59:59.000Z

17

PHOTOMETRY OF VARIABLE STARS FROM DOME A, ANTARCTICA: RESULTS FROM THE 2010 OBSERVING SEASON  

SciTech Connect (OSTI)

We present results from a season of observations with the Chinese Small Telescope ARray, obtained over 183 days of the 2010 Antarctic winter. We carried out high-cadence time-series aperture photometry of 9125 stars with i ?< 15.3 mag located in a 23 deg{sup 2} region centered on the south celestial pole. We identified 188 variable stars, including 67 new objects relative to our 2008 observations, thanks to broader synoptic coverage, a deeper magnitude limit, and a larger field of view. We used the photometric data set to derive site statistics from Dome A. Based on two years of observations, we find that extinction due to clouds at this site is less than 0.1 and 0.4 mag during 45% and 75% of the dark time, respectively.

Wang, Lingzhi; Zhu, Zonghong [Department of Astronomy, Beijing Normal University, Beijing 100875 (China); Macri, Lucas M.; Wang, Lifan [Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Ashley, Michael C. B.; Lawrence, Jon S.; Luong-Van, Daniel; Storey, John W. V. [School of Physics, University of New South Wales, NSW 2052 (Australia); Cui, Xiangqun; Feng, Long-Long; Gong, Xuefei; Liu, Qiang; Shang, Zhaohui; Yang, Huigen; Yang, Ji; Yuan, Xiangyan; Zhou, Xu; Zhu, Zhenxi [Chinese Center for Antarctic Astronomy, Nanjing 210008 (China); Pennypacker, Carl R. [Center for Astrophysics, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); York, Donald G., E-mail: wanglingzhi@bao.ac.cn [Department of Astronomy and Astrophysics and Enrico Fermi Institute, University of Chicago, Chicago, IL 60637 (United States)

2013-12-01T23:59:59.000Z

18

First XMM-Newton observations of a Cataclysmic Variable I: Timing studies of OY Car  

E-Print Network [OSTI]

We present XMM-Newton observations of the eclipsing, disc accreting, cataclysmic variable OY Car which were obtained as part of the performance verification phase of the mission. The star was observed 4 days after an outburst and then again 5 weeks later when it was in a quiescent state. There is a quasi-stable modulation of the X-rays at ~2240 sec, which is most prominent at the lowest energies. We speculate that this may be related to the spin period of the white dwarf. The duration of the eclipse ingress and egress in X-rays is 20--30 sec. This indicates that the bulk of the X-ray emission originates from the boundary layer which has a negligible height above the surface of the white dwarf. The eclipse profile implies a white dwarf of mass M_{1}=0.9-1.1Msun and a secondary star of M_{2}=0.08-0.11Msun.

Gavin Ramsay; Tracey Poole; Keith Mason; France Cordova; William Priedhorsky; Alice Breeveld; Rudi Much; Julian Osborne; Dirk Pandel; Stephen Potter; Jennifer West; Peter Wheatley

2000-10-18T23:59:59.000Z

19

Variability of tropical cyclone track density in the2 North Atlantic: Observations and high-resolution3  

E-Print Network [OSTI]

; Emanuel 2005a)59 and the accumulated cyclone energy (ACE; Bell et al. 2000). Our focus here is on60 1 1 Variability of tropical cyclone track density in the2 North Atlantic: Observations #12; 2 Abstract23 24 Interannual-decadal variability of tropical cyclone (TC) track density

Xie, Shang-Ping

20

Regional Climate Variability in the Western U.S.: Observed vs. Anticipated  

E-Print Network [OSTI]

Temperature Trends #12;More remarks on climate variability&trends Climate = GHG + `Natural Variability'+ Surface Changes + Noise GHG: Greenhouse-gas-related `Global Change' Natural Variability: Decadal (PDO Cycle · ENSO Footprint(s) · Recent Climate Trends · Outlook to Mid-21st Century Range Mgmt. Symposium

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Observed Synoptic-Scale Variability during the Developing Phase of an ISO over the Indian Ocean during MISMO  

E-Print Network [OSTI]

Observed Synoptic-Scale Variability during the Developing Phase of an ISO over the Indian Ocean A case study of an intraseasonal oscillation (ISO) is investigated in the period leading up to its for a convectively active phase of the ISO. The prominent shallow heating during this period may explain the rather

Johnson, Richard H.

22

SPECTRAL VARIABILITY OF FIRST BRIGHT QSOs WITH SLOAN DIGITAL SKY SURVEY OBSERVATIONS  

SciTech Connect (OSTI)

For some samples, it has been shown that spectra of QSOs with low redshift are bluer during their brighter phases. For the FIRST bright QSO sample, we assemble their spectra from Sloan Digital Sky Survey Data Release 7 (SDSS DR7) to investigate variability between the spectra from White et al. and from the SDSS for a long rest-frame time lag, up to 10 years. There are 312 radio-loud (RL) QSOs and 232 radio-quiet (RQ) QSOs in this sample, up to z {approx} 3.5. With two-epoch variation, it is found that the spectra of half of the QSOs appear redder during their brighter phases. There is no obvious difference in slope variability between subsamples of RQ and RL QSOs. This result implies that the presence of a radio jet does not affect the slope variability on 10 year timescales. The arithmetic composite difference spectrum for variable QSOs is steep blueward of {approx}2500 A. The variability for the region blueward of 2500 A is different to that for the region redward of 2500 A.

Bian Weihao; Zhang Li [Department of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing 210097 (China); Green, Richard [LBT Observatory, AZ 85721 (United States); Hu Chen [Key Laboratory for Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100039 (China)

2012-11-10T23:59:59.000Z

23

Interannual and seasonal variability of biomass burning emissions constrained by satellite observations  

E-Print Network [OSTI]

--composition and chemistry; KEYWORDS: Biomass burning, interannual seasonal variation Citation: Duncan, B. N., R. V. Martin, A. C. Staudt, R. Yevich, and J. A. Logan, Interannual and seasonal variability of biomass burning [Malingreau, 1990; Stricker et al., 1995; Hsu et al., 1996; Cooke et al., 1996; Justice et al., 1996; Herman

Jacob, Daniel J.

24

On Channel State Inference and Prediction Using Observable Variables in 802.11b Network  

E-Print Network [OSTI]

strength of each individual bit, are not observable at higher layers. Therefore, it is essential/prediction (CSI/CSP). Here, inference specifically refers to estimating the BER in an already received packet that analyzes the utility of SSR and as side-information for CSI/CSP. In this work, we exploit the Method

Radha, Hayder

25

CoRoT observations of O stars: diverse origins of variability  

E-Print Network [OSTI]

Six O-type stars were observed continuously by the CoRoT satellite during a 34.3-day run. The unprecedented quality of the data allows us to detect even low-amplitude stellar pulsations in some of these stars (HD 46202 and the binaries HD 46149 and Plaskett's star). These cover both opacity-driven modes and solar-like stochastic oscillations, both of importance to the asteroseismological modelling of O stars. Additional effects can be seen in the CoRoT light curves, such as binarity and rotational modulation. Some of the hottest O-type stars (HD 46223, HD 46150 and HD 46966) are dominated by the presence of red-noise: we speculate that this is related to a sub-surface convection zone.

Blomme, R; Degroote, P; Mahy, L; Aerts, C; Cuypers, J; Godart, M; Gosset, E; Hareter, M; Montalban, J; Morel, T; Nieva, M F; Noels, A; Oreiro, R; Poretti, E; Przybilla, N; Rainer, M; Rauw, G; Schiller, F; Simon-Diaz, S; Smolders, K; Ventura, P; Vuckovic, M; Auvergne, M; Baglin, A; Baudin, F; Catala, C; Michel, E; Samadi, R

2011-01-01T23:59:59.000Z

26

Year-round observations of carbon biomass and flux variability in the Southern Ocean  

SciTech Connect (OSTI)

Three Carbon Explorer (CE) floats profiling to kilometer depths in the Southern Ocean tracked dawn-dusk variations of mixing/stratification, particulate organic carbon (POC), and light scattering and sedimentation at 100, 250, and 800 m continuously from January 2002 to April 2003. Data were analyzed in conjunction with contemporaneous satellite winds and chlorophyll and derived subsurface light fields. The CE deployed at 66{sup o}S 172{sup o}W operated in the ice edge zone in absence of light. Two CEs deployed at 55{sup o}S 172{sup o}W recorded wintertime mixing to {approx}400 m, yet observed very different bloom dynamics and sedimentation the following spring. Four hypotheses are explored. The strongest is that shallow transient stratification of the deep winter mixed layer to shallower than photosynthetic critical depth occurred more frequently in the non-bloom/higher sedimentation case. The lower particle export to 800 m under the bloom was hypothesized to be due to higher interception of sinking carbon by a relatively starved over wintering zooplankton population. In the Southern Ocean surface phytoplankton biomass may counter indicate particle flux at kilometer depths.

Bishop, James K.B.; Wood, Todd

2009-02-01T23:59:59.000Z

27

EXPLORING THE MECHANISMS OF VARIABILITY IN CLASS I AND II YSOS WITH TWO-EPOCH HST/NICMOS OBSERVATIONS. A. S. Cotera1  

E-Print Network [OSTI]

to variable accretion processes onto the stellar photosphere [e.g. 2]. The timescales of the variability of the objects, L1551 IRS 5 and HH 30 were observed as part of GTO 7228 (PI: Young), while the other five, Co

Schneider, Glenn

28

MELE: Maximum Entropy Leuven Estimators  

E-Print Network [OSTI]

of the Generalized Maximum Entropy Estimator of the Generaland Douglas Miller, Maximum Entropy Econometrics, Wiley andCalifornia Davis MELE: Maximum Entropy Leuven Estimators by

Paris, Quirino

2001-01-01T23:59:59.000Z

29

Maximum Entropy Correlated Equilibria  

E-Print Network [OSTI]

We study maximum entropy correlated equilibria in (multi-player)games and provide two gradient-based algorithms that are guaranteedto converge to such equilibria. Although we do not provideconvergence rates for these ...

Ortiz, Luis E.

2006-03-20T23:59:59.000Z

30

Variability in the North Atlantic Deep Western Boundary Current : upstream causes and downstream effects as observed at Line W  

E-Print Network [OSTI]

The variability in the DWBC, its connection to the forcing in the northern North Atlantic and interaction with the Gulf Stream were explored from a combination of remote sensing and in-situ measurements in the western North ...

Pea-Molino, Beatriz

2010-01-01T23:59:59.000Z

31

Observation of Strong Variability in the X-Ray Emission from Markarian 421 Correlated with the May 1996 TeV Flare  

E-Print Network [OSTI]

We observed the BL Lac object Markarian 421 with the X-ray satellite RXTE and the Whipple Air Cerenkov Telescope during a two week correlated X-ray/gamma-ray campaign in May 1996. Two dramatic outbursts with extremely rapid and strong flux variations were observed at TeV energies during this period. The X-ray emission in the 2-10 keV band was highly variable and reached a peak flux of $5.6\\times10^{-10}$ erg cm$^{-2}$ s$^{-1}$, a historic high. Similar behavior was observed for the TeV emission. In contrast to earlier near-simultaneous X-ray/gamma-ray observations of Mrk 421, the variability amplitude is much larger at TeV than at X-ray energies. This behavior is expected in Synchrotron Self-Compton models.

Michael Schubnell

1997-07-11T23:59:59.000Z

32

Observations  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the ContributionsArmsSpeedingSpeedingUnder Well-ControlledObservation ofof Multiple

33

Time-variable gravity observations of ice sheet mass balance: Precision and limitations of the GRACE satellite data  

E-Print Network [OSTI]

contribution to sea-level rise observed by GRACE withand ice caps to sea level rise, Nature, 482, 514518. King,ice sheets to sea level rise, Geophys. Res. Lett. , 38,

Velicogna, I.; Wahr, J.

2013-01-01T23:59:59.000Z

34

Time-variable gravity observations of ice sheet mass balance: Precision and limitations of the GRACE satellite data  

E-Print Network [OSTI]

observations, Science, 314, Peltier, W. R. (2004), Globalice history models (ICE5G [Peltier, 2004] and Fleming andfor Greenland; ICE5G [Peltier, 2004] and IJ05 [Ivins and

Velicogna, I.; Wahr, J.

2013-01-01T23:59:59.000Z

35

First XMM-Newton observations of a cataclysmic variable II: the X-ray spectrum of OY Car  

E-Print Network [OSTI]

We present XMM-Newton X-ray spectra of the disc accreting cataclysmic variable OY Car, which were obtained during the performance verification phase of the mission. These data were taken 4 days after a short outburst. In the EPIC spectra we find strong iron Kalpha emission with weaker iron Kbeta emission together with silicon and sulphur lines. The spectra are best fitted with a three temperature plasma model with a partial covering absorber. Multiple temperature emission is confirmed by the emission lines seen in the RGS spectrum and the H/He like intensity ratio for iron and sulphur which imply temperatures of ~7keV and ~3keV respectively.

Gavin Ramsay; France Cordova; Jean Cottam; Keith Mason; Rudi Much; Julian Osborne; Dirk Pandel; Tracey Poole; Peter Wheatley

2000-10-20T23:59:59.000Z

36

The Study of TeV Variability and Duty Cycle of Mrk 421 from 3 Years of Observations with the Milagro Observatory  

E-Print Network [OSTI]

TeV flaring activity with time scales as short as tens of minutes and an orphan TeV flare have been observed from the blazar Markarian 421 (Mrk 421). The TeV emission from Mrk 421 is believed to be produced by leptonic synchrotron self-Compton (SSC) emission. In this scenario, correlations between the X-ray and the TeV fluxes are expected, TeV orphan flares are hardly explained and the activity (measured as duty cycle) of the source at TeV energies is expected to be equal or less than that observed in X-rays if only SSC is considered. To estimate the TeV duty cycle of Mrk 421 and to establish limits on its variability at different time scales, we continuously observed Mrk 421 with the Milagro observatory. Mrk 421 was detected by Milagro with a statistical significance of 7.1 standard deviations between 2005 September 21 and 2008 March 15. The observed spectrum is consistent with previous observations by VERITAS. We estimate the duty cycle of Mrk 421 for energies above 1 TeV for different hypothesis of the bas...

Abdo, A A; Allen, B T; Aune, T; Barber, A S; Berley, D; Braun, J; Chen, C; Christopher, G E; Delay, R S; DeYoung, T; Dingus, B L; Ellsworth, R W; Fraija, N; Gonzlez, M M; Goodman, J A; Hays, E; Hoffman, C M; Hntemeyer, P H; Imran, A; Kolterman, B E; Linnemann, J T; Marinelli, A; McEnery, J E; Morgan, T; Mincer, A I; Nemethy, P; Patricelli, B; Pretz, J; Ryan, J M; Parkinson, P M Saz; Schneider, M; Shoup, A; Sinnis, G; Smith, A J; Vasileiou, V; Walker, G P; Williams, D A; Yodh, G B

2014-01-01T23:59:59.000Z

37

Single ion heat engine with maximum efficiency at maximum power  

E-Print Network [OSTI]

We propose an experimental scheme to realize a nano heat engine with a single ion. An Otto cycle may be implemented by confining the ion in a linear Paul trap with tapered geometry and coupling it to engineered laser reservoirs. The quantum efficiency at maximum power is analytically determined in various regimes. Moreover, Monte Carlo simulations of the engine are performed that demonstrate its feasibility and its ability to operate at maximum efficiency of 30% under realistic conditions.

Obinna Abah; Johannes Rossnagel; Georg Jacob; Sebastian Deffner; Ferdinand Schmidt-Kaler; Kilian Singer; Eric Lutz

2012-05-07T23:59:59.000Z

38

Tissue Radiation Response with Maximum Tsallis Entropy  

SciTech Connect (OSTI)

The expression of survival factors for radiation damaged cells is currently based on probabilistic assumptions and experimentally fitted for each tumor, radiation, and conditions. Here, we show how the simplest of these radiobiological models can be derived from the maximum entropy principle of the classical Boltzmann-Gibbs expression. We extend this derivation using the Tsallis entropy and a cutoff hypothesis, motivated by clinical observations. The obtained expression shows a remarkable agreement with the experimental data found in the literature.

Sotolongo-Grau, O.; Rodriguez-Perez, D.; Antoranz, J. C.; Sotolongo-Costa, Oscar [UNED, Departamento de Fisica Matematica y de Fluidos, 28040 Madrid (Spain); UNED, Departamento de Fisica Matematica y de Fluidos, 28040 Madrid (Spain) and University of Havana, Catedra de Sistemas Complejos Henri Poincare, Havana 10400 (Cuba); University of Havana, Catedra de Sistemas Complejos Henri Poincare, Havana 10400 (Cuba)

2010-10-08T23:59:59.000Z

39

Weak Scale From the Maximum Entropy Principle  

E-Print Network [OSTI]

The theory of multiverse and wormholes suggests that the parameters of the Standard Model are fixed in such a way that the radiation of the $S^{3}$ universe at the final stage $S_{rad}$ becomes maximum, which we call the maximum entropy principle. Although it is difficult to confirm this principle generally, for a few parameters of the Standard Model, we can check whether $S_{rad}$ actually becomes maximum at the observed values. In this paper, we regard $S_{rad}$ at the final stage as a function of the weak scale ( the Higgs expectation value ) $v_{h}$, and show that it becomes maximum around $v_{h}={\\cal{O}}(300\\text{GeV})$ when the dimensionless couplings in the Standard Model, that is, the Higgs self coupling, the gauge couplings, and the Yukawa couplings are fixed. Roughly speaking, we find that the weak scale is given by \\begin{equation} v_{h}\\sim\\frac{T_{BBN}^{2}}{M_{pl}y_{e}^{5}},\

Yuta Hamada; Hikaru Kawai; Kiyoharu Kawana

2014-09-23T23:59:59.000Z

40

Weak Scale From the Maximum Entropy Principle  

E-Print Network [OSTI]

The theory of multiverse and wormholes suggests that the parameters of the Standard Model are fixed in such a way that the radiation of the $S^{3}$ universe at the final stage $S_{rad}$ becomes maximum, which we call the maximum entropy principle. Although it is difficult to confirm this principle generally, for a few parameters of the Standard Model, we can check whether $S_{rad}$ actually becomes maximum at the observed values. In this paper, we regard $S_{rad}$ at the final stage as a function of the weak scale ( the Higgs expectation value ) $v_{h}$, and show that it becomes maximum around $v_{h}={\\cal{O}}(300\\text{GeV})$ when the dimensionless couplings in the Standard Model, that is, the Higgs self coupling, the gauge couplings, and the Yukawa couplings are fixed. Roughly speaking, we find that the weak scale is given by \\begin{equation} v_{h}\\sim\\frac{T_{BBN}^{2}}{M_{pl}y_{e}^{5}},\

Hamada, Yuta; Kawana, Kiyoharu

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Maximum power tracking control scheme for wind generator systems  

E-Print Network [OSTI]

The purpose of this work is to develop a maximum power tracking control strategy for variable speed wind turbine systems. Modern wind turbine control systems are slow, and they depend on the design parameters of the turbine and use wind and/or rotor...

Mena Lopez, Hugo Eduardo

2008-10-10T23:59:59.000Z

42

Maximum power tracking control scheme for wind generator systems  

E-Print Network [OSTI]

The purpose of this work is to develop a maximum power tracking control strategy for variable speed wind turbine systems. Modern wind turbine control systems are slow, and they depend on the design parameters of the turbine and use wind and/or rotor...

Mena, Hugo Eduardo

2009-05-15T23:59:59.000Z

43

Estimating a mixed strategy employing maximum entropy  

E-Print Network [OSTI]

MIXED STRATEGY EMPLOYING MAXIMUM ENTROPY by Amos Golan LarryMixed Strategy Employing Maximum Entropy Amos Golan Larry S.Abstract Generalized maximum entropy may be used to estimate

Golan, Amos; Karp, Larry; Perloff, Jeffrey M.

1996-01-01T23:59:59.000Z

44

MaximumLetThrough.PDF  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces andMapping the Nanoscale LandscapeImportsBG NorthMauro9 Maximum Let-Through

45

Reply to 'Comment on 'All quantum observables in a hidden-variable model must commute simultaneously'' [Phys. Rev. A 73, 066101 (2006)  

SciTech Connect (OSTI)

Nagata [Phys. Rev. A 73, 066101 (2006)] questions whether a general no-go theorem of Malley [Phys. Rev. A 69, 022118 (2004)] applies to local hidden variables and outlines a 'counterexample.' In fact this is not a counterexample at all, but in seeing why it fails we clarify the significance of Malley's result and its relation to other no-go theorems.

Malley, J. D. [Center for Information Technology, NIH, Bethesda, Maryland 20892 (United States); Fine, A. [Department of Philosophy, University of Washington, Seattle, Washington 98195 (United States)

2006-06-15T23:59:59.000Z

46

The Compton hump and variable blue wing in the extreme low-flux NuSTAR observations of 1H0707-495  

E-Print Network [OSTI]

The Narrow-line Seyfert I galaxy, 1H0707-495, has been well observed in the 0.3-10 keV band, revealing a dramatic drop in flux in the iron K alpha band, a strong soft excess, and short timescale reverberation lags associated with these spectral features. In this paper, we present the first results of a deep 250 ks NuSTAR observation of 1H0707-495, which includes the first sensitive observations above 10 keV. Even though the NuSTAR observations caught the source in an extreme low-flux state, the Compton hump is still significantly detected. NuSTAR, with its high effective area above 7 keV, clearly detects the drop in flux in the iron K alpha band, and by comparing these observations with archival XMM-Newton observations, we find that the energy of this drop increases with increasing flux. We discuss possible explanations for this, the most likely of which is that the drop in flux is the blue wing of the relativistically broadened iron K alpha emission line. When the flux is low, the coronal source height is lo...

Kara, E; Lohfink, A M; Parker, M L; Walton, D J; Boggs, S E; Christensen, F E; Hailey, C J; Harrison, F A; Matt, G; Reynolds, C S; Stern, D; Zhang, W W

2015-01-01T23:59:59.000Z

47

Maximum entanglement in squeezed boson and fermion states  

SciTech Connect (OSTI)

A class of squeezed boson and fermion states is studied with particular emphasis on the nature of entanglement. We first investigate the case of bosons, considering two-mode squeezed states. Then we construct the fermion version to show that such states are maximum entangled, for both bosons and fermions. To achieve these results, we demonstrate some relations involving squeezed boson states. The generalization to the case of fermions is made by using Grassmann variables.

Khanna, F. C. [Theoretical Physics Institute, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada); TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Malbouisson, J. M. C. [Instituto de Fisica, Universidade Federal da Bahia, 40210-340, Salvador, BA (Brazil); Theoretical Physics Institute, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada); Santana, A. E. [Instituto de Fisica, Universidade de Brasilia, 70910-900, Brasilia, DF (Brazil); Theoretical Physics Institute, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada); Santos, E. S. [Centro Federal de Educacao Tecnologica da Bahia, 40030-010, Salvador, BA (Brazil)

2007-08-15T23:59:59.000Z

48

Maximum entropy principal for transportation  

SciTech Connect (OSTI)

In this work we deal with modeling of the transportation phenomenon for use in the transportation planning process and policy-impact studies. The model developed is based on the dependence concept, i.e., the notion that the probability of a trip starting at origin i is dependent on the probability of a trip ending at destination j given that the factors (such as travel time, cost, etc.) which affect travel between origin i and destination j assume some specific values. The derivation of the solution of the model employs the maximum entropy principle combining a priori multinomial distribution with a trip utility concept. This model is utilized to forecast trip distributions under a variety of policy changes and scenarios. The dependence coefficients are obtained from a regression equation where the functional form is derived based on conditional probability and perception of factors from experimental psychology. The dependence coefficients encode all the information that was previously encoded in the form of constraints. In addition, the dependence coefficients encode information that cannot be expressed in the form of constraints for practical reasons, namely, computational tractability. The equivalence between the standard formulation (i.e., objective function with constraints) and the dependence formulation (i.e., without constraints) is demonstrated. The parameters of the dependence-based trip-distribution model are estimated, and the model is also validated using commercial air travel data in the U.S. In addition, policy impact analyses (such as allowance of supersonic flights inside the U.S. and user surcharge at noise-impacted airports) on air travel are performed.

Bilich, F. [University of Brasilia (Brazil); Da Silva, R. [National Research Council (Brazil)

2008-11-06T23:59:59.000Z

49

Vegetation and Fire at the Last Glacial Maximum in Tropical South America  

E-Print Network [OSTI]

Chapter 4 Vegetation and Fire at the Last Glacial Maximum in Tropical South America Francis E temperatures. Keywords Charcoal · Last Glacial Maximum · pollen · Quaternary · tropical South America F-mail: Francis.Mayle@ed.ac.uk 89F. Vimeux et al. (eds.), Past Climate Variability in South America

Binford, Michael W.

50

Spatial Variability in the Ratio of Interstellar Atomic Deuterium to Hydrogen. I. Observations toward delta Orionis by the Interstellar Medium Absorption Profile Spectrograph  

E-Print Network [OSTI]

Studies of the abundances of deuterium in different astrophysical sites are of fundamental importance to answering the question about how much deuterium was produced during big bang nucleosynthesis and what fraction of it was destroyed later. With this in mind, we used the Interstellar Medium Absorption Profile Spectrograph (IMAPS) on the ORFEUS-SPAS II mission to observe at a wavelength resolution of 4 km/s (FWHM) the L-delta and L-epsilon absorption features produced by interstellar atomic deuterium in the spectrum of delta Ori A. A chi-square analysis indicated that 0.96 atomic ratio of D to H, we measured the L-alpha absorption features in 57 spectra of delta Ori in the IUE archive. From our measurement of N(H I)= 1.56e20 cm^{-2}, we found that N(D I)/N(H I)= 7.4(+1.9,-1.3)e-6 (90% confidence). Our result for D/H contrasts with the more general finding along other lines of sight that D/H is approximately 1.5e-5. The underabundance of D toward delta Ori A is not accompanied by an overabundance of N or O relative to H, as one might expect if the gas were subjected to more stellar processing than usual.

Edward B. Jenkins; Todd M. Tripp; Przemyslaw R. Wozniak; Ulysses J. Sofia; G. Sonneborn

1999-01-28T23:59:59.000Z

51

NGC2613, 3198, 6503, 7184: Case studies against `maximum' disks  

E-Print Network [OSTI]

Decompositions of the rotation curves of NGC2613, 3198, 6505, and 7184 are analysed. For these galaxies the radial velocity dispersions of the stars have been measured and their morphology is clearly discernible. If the parameters of the decompositions are chosen according to the `maximum' disk hypothesis, the Toomre Q stability parameter is systematically less than one and the multiplicities of the spiral arms as expected from density wave theory are inconsitent with the observed morphologies of the galaxies. The apparent Q<1 instability, in particular, is a strong argument against the `maximum' disk hypothesis.

B. Fuchs

1998-12-02T23:59:59.000Z

52

When are microcircuits well-modeled by maximum entropy methods?  

E-Print Network [OSTI]

POSTER PRESENTATION Open Access When are microcircuits well-modeled by maximum entropy methods? Andrea K Barreiro1*, Eric T Shea-Brown1, Fred M Rieke2,3, Julijana Gjorgjieva4 From Nineteenth Annual Computational Neuroscience Meeting: CNS*2010 San... Antonio, TX, USA. 24-30 July 2010 Recent experiments in retina and cortex have demon- strated that pairwise maximum entropy (PME) methods can approximate observed spiking patterns to a high degree of accuracy [1,2]. In this paper we examine...

2010-07-20T23:59:59.000Z

53

Valence quark distributions of the proton from maximum entropy approach  

E-Print Network [OSTI]

We present an attempt of maximum entropy principle to determine valence quark distributions in the proton at very low resolution scale $Q_0^2$. The initial three valence quark distributions are obtained with limited dynamical information from quark model and QCD theory. Valence quark distributions from this method are compared to the lepton deep inelastic scattering data, and the widely used CT10 and MSTW08 data sets. The obtained valence quark distributions are consistent with experimental observations and the latest global fits of PDFs. Maximum entropy method is expected to be particularly useful in the case where relatively little information from QCD calculation is given.

Rong Wang; Xurong Chen

2014-10-14T23:59:59.000Z

54

Valence quark distributions of the proton from maximum entropy approach  

E-Print Network [OSTI]

We present an attempt of maximum entropy principle to determine valence quark distributions in the proton at very low resolution scale $Q_0^2$. The initial three valence quark distributions are obtained with limited dynamical information from quark model and QCD theory. Valence quark distributions from this method are compared to the lepton deep inelastic scattering data, and the widely used CT10 and MSTW08 data sets. The obtained valence quark distributions are consistent with experimental observations and the latest global fits of PDFs. Maximum entropy method is expected to be particularly useful in the case where relatively little information from QCD calculation is given.

Wang, Rong

2014-01-01T23:59:59.000Z

55

Maximum stellar mass versus cluster membership number revisited  

E-Print Network [OSTI]

We have made a new compilation of observations of maximum stellar mass versus cluster membership number from the literature, which we analyse for consistency with the predictions of a simple random drawing hypothesis for stellar mass selection in clusters. Previously, Weidner and Kroupa have suggested that the maximum stellar mass is lower, in low mass clusters, than would be expected on the basis of random drawing, and have pointed out that this could have important implications for steepening the integrated initial mass function of the Galaxy (the IGIMF) at high masses. Our compilation demonstrates how the observed distribution in the plane of maximum stellar mass versus membership number is affected by the method of target selection; in particular, rather low n clusters with large maximum stellar masses are abundant in observational datasets that specifically seek clusters in the environs of high mass stars. Although we do not consider our compilation to be either complete or unbiased, we discuss the method by which such data should be statistically analysed. Our very provisional conclusion is that the data is not indicating any striking deviation from the expectations of random drawing.

Th. Maschberger; C. J. Clarke

2008-09-05T23:59:59.000Z

56

Rapid Variability of Blazar 3C 279 during Flaring States in 2013-2014 with Joint Fermi-LAT, NuSTAR, Swift, and Ground-Based Multi-wavelength Observations  

E-Print Network [OSTI]

We report the results of a multi-band observing campaign on the famous blazer 3C 279 conducted during a phase of increased activity from 2013 December to 2014 April, including first observations of it with NuSTAR. The $\\gamma$-ray emission of the source measured by Fermi-LAT showed multiple distinct flares reaching the highest flux level measured in this object since the beginning of the Fermi mission, with $F(E > 100\\,{\\rm MeV})$ of $10^{-5}$ photons cm$^{-2}$ s$^{-1}$, and with a flux doubling time scale as short as 2 hours. The $\\gamma$-ray spectrum during one of the flares was very hard, with an index of $\\Gamma_\\gamma = 1.7 \\pm 0.1$, which is rarely seen in flat spectrum radio quasars. The lack of concurrent optical variability implies a very high Compton dominance parameter $L_\\gamma/L_{\\rm syn} > 300$. Two 1-day NuSTAR observations with accompanying Swift pointings were separated by 2 weeks, probing different levels of source activity. While the 0.5$-$70 keV X-ray spectrum obtained during the first poi...

Hayashida, M; Madejski, G M; Sikora, M; Itoh, R; Ajello, M; Blandford, R D; Buson, S; Chiang, J; Fukazawa, Y; Furniss, A K; Urry, C M; Hasan, I; Harrison, F A; Alexander, D M; Balokovi?, M; Barret, D; Boggs, S E; Christensen, F E; Craig, W W; Forster, K; Giommi, P; Grefenstette, B; Hailey, C; Hornstrup, A; Kitaguchi, T; Koglin, J E; Madsen, K K; Mao, P H; Miyasaka, H; Mori, K; Perri, M; Pivovaroff, M J; Puccetti, S; Rana, V; Stern, D; Tagliaferri, G; Westergaard, N J; Zhang, W W; Zoglauer, A; Gurwell, M A; Uemura, M; Akitaya, H; Kawabata, K S; Kawaguch, K; Kanda, Y; Moritani, Y; Takaki, K; Ui, T; Yoshida, M; Agarwal, A; Gupta, A C

2015-01-01T23:59:59.000Z

57

Maximum entropy segmentation of broadcast news  

E-Print Network [OSTI]

speech recognizer and subsequently segmenting the text into utterances and topics. A maximum entropy approach is used to build statistical models for both utterance and topic segmentation. The experimental work addresses the effect on performance...

Christensen, Heidi; Kolluru, BalaKrishna; Gotoh, Yoshihiko; Renals, Steve

2005-01-01T23:59:59.000Z

58

Higher Order Maximum Persistency and Comparison Theorems  

E-Print Network [OSTI]

discrete variables (energy minimization in graphical models, weighted constraint ... 1.2 Energy Minimization . ...... This is useful in proofs, providing an alternative.

2014-10-15T23:59:59.000Z

59

Higher Order Maximum Persistency and Comparison Theorems  

E-Print Network [OSTI]

Oct 15, 2014 ... ... of discrete variables (energy minimization in graphical models, ... for Computer Graphics and Vision, Graz Univeristy of Technology, Oct.

Alexander Shekhovtsov

2014-10-15T23:59:59.000Z

60

Maximum entropy method for reconstruction of the CMB images  

E-Print Network [OSTI]

We propose a new approach for the accurate reconstruction of cosmic microwave background distributions from observations containing in addition to the primary fluctuations the radiation from unresolved extragalactic point sources and pixel noise. The approach uses some effective realizations of the well-known maximum entropy method and principally takes into account {\\it a priori} information about finiteness and spherical symmetry of the power spectrum of the CMB satisfying the Gaussian statistics.

A. T. Bajkova

2002-05-21T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Cell development obeys maximum Fisher information  

E-Print Network [OSTI]

Eukaryotic cell development has been optimized by natural selection to obey maximal intracellular flux of messenger proteins. This, in turn, implies maximum Fisher information on angular position about a target nuclear pore complex (NPR). The cell is simply modeled as spherical, with cell membrane (CM) diameter 10 micron and concentric nuclear membrane (NM) diameter 6 micron. The NM contains about 3000 nuclear pore complexes (NPCs). Development requires messenger ligands to travel from the CM-NPC-DNA target binding sites. Ligands acquire negative charge by phosphorylation, passing through the cytoplasm over Newtonian trajectories toward positively charged NPCs (utilizing positive nuclear localization sequences). The CM-NPC channel obeys maximized mean protein flux F and Fisher information I at the NPC, with first-order delta I = 0 and approximate 2nd-order delta I = 0 stability to environmental perturbations. Many of its predictions are confirmed, including the dominance of protein pathways of from 1-4 proteins, a 4nm size for the EGFR protein and the approximate flux value F =10^16 proteins/m2-s. After entering the nucleus, each protein ultimately delivers its ligand information to a DNA target site with maximum probability, i.e. maximum Kullback-Liebler entropy HKL. In a smoothness limit HKL approaches IDNA/2, so that the total CM-NPC-DNA channel obeys maximum Fisher I. Thus maximum information approaches non-equilibrium, one condition for life.

B. R. Frieden; R. A. Gatenby

2014-04-29T23:59:59.000Z

62

Cataclysmic Variables  

E-Print Network [OSTI]

Cataclysmic variables are binary stars in which a relatively normal star is transferring mass to its compact companion. This interaction gives rise to a rich range of behaviour, of which the most noticeable are the outbursts that give the class its name. Novae belong to the class, as do the less well known dwarf novae and magnetic systems. Novae draw their energy from nuclear reactions, while dwarf novae rely on gravity to power their smaller eruptions. All the different classes of cataclysmic variable can be accommodated within a single framework and this article will describe the framework, review the properties of the main types of system and discuss models of the outbursts and of the long-term evolution.

Robert Connon Smith

2007-01-23T23:59:59.000Z

63

Comparison of VLF Wave Activity in the Solar Wind During Solar Maximum and Minimum  

E-Print Network [OSTI]

second fast latitude scan (near the solar maximum) with the wave observations during the first fast Experiments (URAP) of Ulysses during its first orbit, which occurred when the solar activity was approachingComparison of VLF Wave Activity in the Solar Wind During Solar Maximum and Minimum: Ulysses

California at Berkeley, University of

64

Integrating Correlated Bayesian Networks Using Maximum Entropy  

SciTech Connect (OSTI)

We consider the problem of generating a joint distribution for a pair of Bayesian networks that preserves the multivariate marginal distribution of each network and satisfies prescribed correlation between pairs of nodes taken from both networks. We derive the maximum entropy distribution for any pair of multivariate random vectors and prescribed correlations and demonstrate numerical results for an example integration of Bayesian networks.

Jarman, Kenneth D.; Whitney, Paul D.

2011-08-30T23:59:59.000Z

65

Structure of Turbulence in Katabatic Flows below and above the Wind-Speed Maximum  

E-Print Network [OSTI]

Measurements of small-scale turbulence made over the complex-terrain atmospheric boundary layer during the MATERHORN Program are used to describe the structure of turbulence in katabatic flows. Turbulent and mean meteorological data were continuously measured at multiple levels at four towers deployed along the East lower slope (2-4 deg) of Granite Mountain. The multi-level observations made during a 30-day long MATERHORN-Fall field campaign in September-October 2012 allowed studying of temporal and spatial structure of katabatic flows in detail, and herein we report turbulence and their variations in katabatic winds. Observed vertical profiles show steep gradients near the surface, but in the layer above the slope jet the vertical variability is smaller. It is found that the vertical (normal to the slope) momentum flux and horizontal (along the slope) heat flux in a slope-following coordinate system change their sign below and above the wind maximum of a katabatic flow. The vertical momentum flux is directed...

Grachev, Andrey A; Di Sabatino, Silvana; Fernando, Harindra J S; Pardyjak, Eric R; Fairall, Christopher W

2015-01-01T23:59:59.000Z

66

Interannual variability in tropospheric nitrous oxide  

E-Print Network [OSTI]

Observations of tropospheric N2O mixing ratio show significant variability on interannual timescales (0.2?ppb, 1 standard deviation). We found that interannual variability in N2O is weakly correlated with that in CFC-12 ...

Thompson, R. L.

67

QCD Level Density from Maximum Entropy Method  

E-Print Network [OSTI]

We propose a method to calculate the QCD level density directly from the thermodynamic quantities obtained by lattice QCD simulations with the use of the maximum entropy method (MEM). Understanding QCD thermodynamics from QCD spectral properties has its own importance. Also it has a close connection to phenomenological analyses of the lattice data as well as experimental data on the basis of hadronic resonances. Our feasibility study shows that the MEM can provide a useful tool to study QCD level density.

Shinji Ejiri; Tetsuo Hatsuda

2005-09-24T23:59:59.000Z

68

Maximum-entropy principle for static and dynamic high-field transport in semiconductors  

SciTech Connect (OSTI)

Within the maximum entropy principle we present a general theory able to provide, in a dynamical context, the macroscopic relevant variables for carrier transport under electric fields of arbitrary strength. For the macroscopic variables the linearized maximum entropy approach is developed including full-band effects within a total energy scheme. Under spatially homogeneous conditions, we construct a closed set of hydrodynamic equations for the small-signal (dynamic) response of the macroscopic variables. The coupling between the driving field and the energy dissipation is analyzed quantitatively by using an arbitrary number of moments of the distribution function. The theoretical approach is applied to n-Si at 300 K and is validated by comparing numerical calculations with ensemble Monte Carlo simulations and with experimental data.

Trovato, M. [Dipartimento di Matematica, Universita di Catania, Viale A. Doria, 95125 Catania (Italy); Reggiani, L. [Dipartimento di Ingegneria dell' Innovazione e Nanotechnology National Laboratory of CNR-INFM, Universita di Lecce, Via Arnesano s/n, 73100 Lecce (Italy)

2006-06-15T23:59:59.000Z

69

Maximum likelihood reconstruction for the Daya Bay Experiment  

E-Print Network [OSTI]

The Daya Bay Reactor Neutrino experiment is designed to precisely determine the neutrino mixing angle theta13. In this paper, we report a maximum likelihood (ML) method to reconstruct the vertex and energy of events in the anti-neutrino detector, based on a simplified optical model that describes light propagation. We calibrate the key paramters of the optical model with Co60 source, by comparing the predicted charges of the PMTs with the observed charges. With the optimized parameters, the resolution of the vertex reconstruction is about 25cm for Co60 gamma.

Xia Dongmei

2014-03-07T23:59:59.000Z

70

A global maximum power point tracking DC-DC converter  

E-Print Network [OSTI]

This thesis describes the design, and validation of a maximum power point tracking DC-DC converter capable of following the true global maximum power point in the presence of other local maximum. It does this without the ...

Duncan, Joseph, 1981-

2005-01-01T23:59:59.000Z

71

Intrinsic Absorption Properties in Active Galaxies Observed with the Far Ultraviolet Spectroscopic Explorer  

E-Print Network [OSTI]

In a continuing survey of active galactic nuclei observed by the Far Ultraviolet Spectroscopic Explorer, we provide a deeper analysis of intrinsic absorption features found in 35 objects. Our survey is for low-redshift and moderate-luminosity objects, mostly Seyfert galaxies. We find a strong correlation between maximum radial velocity and luminosity. We also examine the relationships between equivalent width (EW), full width at half maximum, velocity: and continuum flux. The correlation between velocity and luminosity has been explored previously by Laor & Brandt, but at a significantly higher redshift and heavily weighted by broad absorption line quasars. We also have examined each object with multiple observations for variability in each of the aforementioned quantities, and have characterized the variation of EW with the continuum flux. In our survey, we find that variability of O VI lambda1032, lambda1038 is less common than of the UV doublets of CIV and N V seen at longer wavelengths, because the O VI absorption is usually saturated. Lyman beta absorption variability is more frequent. In a target-by-target examination we find that broad absorption line absorption and narrow absorption line absorbers are related in terms of maximum outflow velocity and luminosity, and both can be exhibited in similar luminosity objects. We also find one object that shows radial velocity change, seven objects that show equivalent width variability, and two objects that show either transverse velocity changes or a change in ionization.

Jay P. Dunn; D. Michael Crenshaw; S. B. Kraemer; M. L. Trippe

2008-07-01T23:59:59.000Z

72

Accelerated maximum likelihood parameter estimation for stochastic biochemical systems  

E-Print Network [OSTI]

as: Daigle et al. : Accelerated maximum likelihood parame-Gillespie DT: Approximate accelerated stochastic simulationARTICLE Open Access Accelerated maximum likelihood parameter

Daigle, Bernie J; Roh, Min K; Petzold, Linda R; Niemi, Jarad

2012-01-01T23:59:59.000Z

73

articulatorily constrained maximum: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

weight spanning forests. Amitabha Bagchi; Ankur Bhargava; Torsten Suel 2005-01-01 27 Maximum Entropy Correlated Equilibria MIT - DSpace Summary: We study maximum entropy...

74

Maximum mass of magnetic white dwarfs  

E-Print Network [OSTI]

We revisit in this work the problem of the maximum masses of magnetized White Dwarfs (WD). The impact of a strong magnetic field onto the structure equations is addressed. The pressures become anisotropic due to the presence of the magnetic field and split into a parallel and perpendicular components. We first construct stable solutions of TOV equations for the parallel pressures, and found that physical solutions vanish for the perpendicular pressure when $B \\gtrsim 10^{13}$ G. This fact establishes an upper bound for a magnetic field and the stability of the configurations in the (quasi) spherical approximation. Our findings also indicate that it is not possible to obtain stable magnetized WD with super Chandrasekhar masses because the values of the magnetic field needed for them are higher than this bound. To proceed into the anisotropic regime, we derived structure equations appropriated for a cylindrical metric with anisotropic pressures. From the solutions of the structure equations in cylindrical symme...

Paret, D Manreza; Horvath, J E

2015-01-01T23:59:59.000Z

75

Maximum screening fields of superconducting multilayer structures  

E-Print Network [OSTI]

It is shown that a multilayer comprised of alternating thin superconducting and insulating layers on a thick substrate can fully screen the applied magnetic field exceeding the superheating fields $H_s$ of both the superconducting layers and the substrate, the maximum Meissner field is achieved at an optimum multilayer thickness. For instance, a dirty layer of thickness $\\sim 0.1\\; \\mu$m at the Nb surface could increase $H_s\\simeq 240$ mT of a clean Nb up to $H_s\\simeq 290$ mT. Optimized multilayers of Nb$_3$Sn, NbN, some of the iron pnictides, or alloyed Nb deposited onto the surface of the Nb resonator cavities could potentially double the rf breakdown field, pushing the peak accelerating electric fields above 100 MV/m while protecting the cavity from dendritic thermomagnetic avalanches caused by local penetration of vortices.

Gurevich, Alex

2015-01-01T23:59:59.000Z

76

Maximum Entropy Method Approach to $?$ Term  

E-Print Network [OSTI]

In Monte Carlo simulations of lattice field theory with a $\\theta$ term, one confronts the complex weight problem, or the sign problem. This is circumvented by performing the Fourier transform of the topological charge distribution $P(Q)$. This procedure, however, causes flattening phenomenon of the free energy $f(\\theta)$, which makes study of the phase structure unfeasible. In order to treat this problem, we apply the maximum entropy method (MEM) to a Gaussian form of $P(Q)$, which serves as a good example to test whether the MEM can be applied effectively to the $\\theta$ term. We study the case with flattening as well as that without flattening. In the latter case, the results of the MEM agree with those obtained from the direct application of the Fourier transform. For the former, the MEM gives a smoother $f(\\theta)$ than that of the Fourier transform. Among various default models investigated, the images which yield the least error do not show flattening, although some others cannot be excluded given the uncertainty related to statistical error.

Masahiro Imachi; Yasuhiko Shinno; Hiroshi Yoneyama

2004-06-09T23:59:59.000Z

77

GMM Estimation of a Maximum Entropy Distribution with Interval Data  

E-Print Network [OSTI]

GMM Estimation of a Maximum Entropy Distribution with Interval Data Ximing Wu* and Jeffrey M estimate it using a simple yet flexible maximum entropy density. Our Monte Carlo simulations show that the proposed maximum entropy density is able to approximate various distributions extremely well. The two

Perloff, Jeffrey M.

78

On the "viscosity maximum" during the uniaxial extension of a low density polyethylene  

E-Print Network [OSTI]

An experimental investigation of the viscosity overshoot phenomenon observed during uniaxial extension of a low density polyethylene is pre- sented. For this purpose, traditional integral viscosity measurements on a Muenstedt type extensional rheometer are combined with local mea- surements based on the in-situ visualization of the sample under exten- sion. For elongational experiments at constant strain rates within a wide range of Weissenberg numbers (Wi), three distinct deformation regimes are identified. Corresponding to low values of Wi (regime I), the tensile stress displays a broad maximum. This maximum can be explained by simple mathematical arguments as a result of low deformation rates and it should not be confused with the viscosity overshoot phenomenon. Corre- sponding to intermediate values of Wi (regime II), a local maximum of the integral extensional viscosity is systematically observed. However, within this regime, the local viscosity measurements reveal no maximum, but a plateau. Careful inspection of the images of samples within this regime shows that, corresponding to the maximum of the integral viscosity, sec- ondary necks develop along the sample. The emergence of a maximum of the integral elongational viscosity is thus related to the distinct in- homogeneity of deformation states and is not related to the rheological properties of the material. In the fast stretching limit (high Wi, regime III), the overall geometric uniformity of the sample is well preserved, no secondary necks are observed and both the integral and the local transient elongational viscosity show no maximum. A detailed comparison of the experimental findings with results from literature is presented.

Teodor I. Burghelea; Zdenek Stary; Helmut Muenstedt

2010-01-13T23:59:59.000Z

79

What measures climate? A variety of variables including their variability and extreme values determine climate for  

E-Print Network [OSTI]

climate zones? The sun is the ultimate power source for the climate "machine". The uneven distribution conditions. Typical variables to consider are temperature (maximum, miniumum), precipitation (includes rain, sleet, snow, hail, etc), sunlight/cloudiness, wind, humidity, ice cover, sea temperature, etc... Many

Allan, Richard P.

80

Spectral Modeling of SNe Ia Near Maximum Light: Probing the Characteristics of Hydro Models  

E-Print Network [OSTI]

We have performed detailed NLTE spectral synthesis modeling of 2 types of 1-D hydro models: the very highly parameterized deflagration model W7, and two delayed detonation models. We find that overall both models do about equally well at fitting well observed SNe Ia near to maximum light. However, the Si II 6150 feature of W7 is systematically too fast, whereas for the delayed detonation models it is also somewhat too fast, but significantly better than that of W7. We find that a parameterized mixed model does the best job of reproducing the Si II 6150 line near maximum light and we study the differences in the models that lead to better fits to normal SNe Ia. We discuss what is required of a hydro model to fit the spectra of observed SNe Ia near maximum light.

E. Baron; S. Bongard; David Branch; Peter H. Hauschildt

2006-03-03T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Photothermoacoustic imaging of biological tissues: maximum depth characterization comparison of time and  

E-Print Network [OSTI]

Photothermoacoustic imaging of biological tissues: maximum depth characterization comparison for Advanced Diffusion-Wave Technologies Department of Mechanical and Industrial Engineering 5 King's College induced in light-absorbing materials can be observed either as a transient signal in time domain

Mandelis, Andreas

82

Observed Characteristics of the MJO Relative to Maximum Rainfall JAMES J. BENEDICT AND DAVID A. RANDALL  

E-Print Network [OSTI]

. RANDALL Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado (Manuscript be important (Bladé and Hartmann 1993; Hu and Randall 1994; Kemball-Cook and Weare 2001). Lagged

Randall, David A.

83

Some observations on Goldberg-Trajan's Maximum Flow algorithm on Bipartite Graphs  

E-Print Network [OSTI]

) is a direct graph with two distinguished vertices s (the source) and t (the sink). Each edge [u, v] in G is associated with a positive integer cap(u, v), called the capacity of the edge. If there is no edge from vertex u to vertex v. then we define... cap(u, v) = 0. Intuitively, a flow in a flow network should satisfy the following three conditions: (1) the amount of flow along an edge should not exceed the capacity of the edge (capacity constraint); (2) a flow from a vertex u to a vertex v can...

Yang, Bencai

1997-01-01T23:59:59.000Z

84

AUV Observations of the Diurnal Surface Layer in the North Atlantic3 Salinity Maximum4  

E-Print Network [OSTI]

stabilizing effect of the thermal stratification then inhibits convection and vertical mixing,39 allowing of both types--bow probes mounted forward of a research63 vessel and profiles collected by a free

Fratantoni, David

85

A Near Maximum Likelihood Decoding Algorithm for MIMO Systems ...  

E-Print Network [OSTI]

Jul 30, 2005 ... the randomization procedure of [43], we bijectively map the .... ?1x are also in the integer grid. ... in a Maximum A Posteriori (MAP) decoder by.

2005-10-05T23:59:59.000Z

86

Solving Maximum-Entropy Sampling Problems Using Factored Masks  

E-Print Network [OSTI]

Mar 2, 2005 ... Abstract: We present a practical approach to Anstreicher and Lee's masked spectral bound for maximum-entropy sampling, and we describe...

Samuel Burer

2005-03-02T23:59:59.000Z

87

A masked spectral bound for maximum-entropy sampling  

E-Print Network [OSTI]

Sep 16, 2003 ... Abstract: We introduce a new masked spectral bound for the maximum-entropy sampling problem. This bound is a continuous generalization of...

Kurt Anstreicher

2003-09-16T23:59:59.000Z

88

Maximum entropy generation in open systems: the Fourth Law?  

E-Print Network [OSTI]

This paper develops an analytical and rigorous formulation of the maximum entropy generation principle. The result is suggested as the Fourth Law of Thermodynamics.

Umberto Lucia

2010-11-17T23:59:59.000Z

89

analog fixed maximum: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

state for given entanglement which can be viewed as an analogue of the Jaynes maximum entropy principle. Pawel Horodecki; Ryszard Horodecki; Michal Horodecki 1998-05-22...

90

IBM Research Report Solving Maximum-Entropy Sampling ...  

E-Print Network [OSTI]

Feb 28, 2005 ... Solving Maximum-Entropy Sampling Problems Using. Factored Masks. Samuel Burer. Department of Management Sciences. University of Iowa.

2005-02-28T23:59:59.000Z

91

A Requirement for Significant Reduction in the Maximum BTU Input...  

Energy Savers [EERE]

A Requirement for Significant Reduction in the Maximum BTU Input Rate of Decorative Vented Gas Fireplaces Would Impose Substantial Burdens on Manufacturers A Requirement for...

92

Maximum Constant Boost Control of the Z-Source Inverter  

E-Print Network [OSTI]

Maximum Constant Boost Control of the Z-Source Inverter Miaosen Shen1 , Jin Wang1 , Alan Joseph1 Laboratory Abstract: This paper proposes two maximum constant boost control methods for the Z-source inverter to modulation index is analyzed in detail and verified by simulation and experiment. Keywords- Z-source inverter

Tolbert, Leon M.

93

Appendix 22 Draft Nutrient Management Plan and Total Maximum Daily  

E-Print Network [OSTI]

Appendix 22 Draft Nutrient Management Plan and Total Maximum Daily Load for Flathead Lake, Montana. #12;11/01/01 DRAFT i October 30, 2001 Draft Nutrient Management Plan and Total Maximum Daily Load..............................................................................................................................2-11 SECTION 3.0 APPLICABLE WATER QUALITY STANDARDS

94

A reliable, fast and low cost maximum power point tracker for photovoltaic applications  

SciTech Connect (OSTI)

This work presents a new maximum power point tracker system for photovoltaic applications. The developed system is an analog version of the ''P and O-oriented'' algorithm. It maintains its main advantages: simplicity, reliability and easy practical implementation, and avoids its main disadvantages: inaccurateness and relatively slow response. Additionally, the developed system can be implemented in a practical way at a low cost, which means an added value. The system also shows an excellent behavior for very fast variables in incident radiation levels. (author)

Enrique, J.M.; Andujar, J.M.; Bohorquez, M.A. [Departamento de Ingenieria Electronica, de Sistemas Informaticos y Automatica, Universidad de Huelva (Spain)

2010-01-15T23:59:59.000Z

95

Conditional maximum-entropy method for selecting prior distributions in Bayesian statistics  

E-Print Network [OSTI]

The conditional maximum-entropy method (abbreviated here as C-MaxEnt) is formulated for selecting prior probability distributions in Bayesian statistics for parameter estimation. This method is inspired by a statistical-mechanical approach to systems governed by dynamics with largely-separated time scales and is based on three key concepts: conjugate pairs of variables, dimensionless integration measures with coarse-graining factors and partial maximization of the joint entropy. The method enables one to calculate a prior purely from a likelihood in a simple way. It is shown in particular how it not only yields Jeffreys's rules but also reveals new structures hidden behind them.

Abe, Sumiyoshi

2014-01-01T23:59:59.000Z

96

Maximum Entropy and the Stress Distribution in Soft Disk Packings Above Jamming  

E-Print Network [OSTI]

We show that the maximum entropy hypothesis can successfully explain the distribution of stresses on compact clusters of particles within disordered mechanically stable packings of soft, isotropically stressed, frictionless disks above the jamming transition. We show that, in our two dimensional case, it becomes necessary to consider not only the stress but also the Maxwell-Cremona force-tile area, as a constraining variable that determines the stress distribution. The importance of the force-tile area was suggested by earlier computations on an idealized force-network ensemble.

Yegang Wu; S. Teitel

2014-10-17T23:59:59.000Z

97

Principal Components Instrumental Variable Estimation  

E-Print Network [OSTI]

of the main results are displayed in two appendices. 2 Econometric Framework Consider the simultaneous equations model y = X? + u and X = Z?+ V , (1) 1 An advantage of such general structure is that the large-sample condition used in previous studies Kn/ p n... ? 0, where Kn is the number of instruments and n is the sample size, is not required in our asymptotic approximations. 4 where y is the n 1 vector containing n observations of the dependent variable; X is the n G matrix with observations...

Winkelried, Diego; Smith, Richard J.

2011-01-31T23:59:59.000Z

98

atlantic oscillation variability: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

human-induced global warming, or a combination of both factors, have been suggested. Several previous studies have discussed observed multidecadal variability in the...

99

Linearized semiclassical initial value time correlation functions with maximum entropy analytic continuation  

E-Print Network [OSTI]

1992). J. Skilling, in Maximum entropy and Bayesian methods,1989). S. F. Gull, in Maximum entropy and Bayesian methods,with the classical maximum entropy (CME) technique (MEAC-

Liu, Jian

2008-01-01T23:59:59.000Z

100

Improved constraints on transit time distributions from argon 39: A maximum entropy approach  

E-Print Network [OSTI]

Gull (1991), Bayesian maximum entropy image reconstruction,Atlantic venti- lated? Maximum entropy inversions of bottlefrom argon 39: A maximum entropy approach Mark Holzer 1,2

Holzer, Mark; Primeau, Francois W

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Quantum Statistics Basis, Thermodynamic Analogies and the Degree of Confidence for Maximum Entropy Restoration and Estimation  

E-Print Network [OSTI]

of Confidence for Maximum Entropy Restoration and EstimationApril 3, 1992) The Maximum Entropy method, using physicalare discussed. Maximum Entropy (ME) estimation has been

Soffer, Bernard H; Kikuchi, Ryoichi

1994-01-01T23:59:59.000Z

102

On the maximum pressure rise rate in boosted HCCI operation  

E-Print Network [OSTI]

This paper explores the combined effects of boosting, intake air temperature, trapped residual gas fraction, and dilution on the Maximum Pressure Rise Rate (MPRR) in a boosted single cylinder gasoline HCCI engine with ...

Wildman, Craig B.

103

Maximum Photovoltaic Penetration Levels on Typical Distribution Feeders: Preprint  

SciTech Connect (OSTI)

This paper presents simulation results for a taxonomy of typical distribution feeders with various levels of photovoltaic (PV) penetration. For each of the 16 feeders simulated, the maximum PV penetration that did not result in steady-state voltage or current violation is presented for several PV location scenarios: clustered near the feeder source, clustered near the midpoint of the feeder, clustered near the end of the feeder, randomly located, and evenly distributed. In addition, the maximum level of PV is presented for single, large PV systems at each location. Maximum PV penetration was determined by requiring that feeder voltages stay within ANSI Range A and that feeder currents stay within the ranges determined by overcurrent protection devices. Simulations were run in GridLAB-D using hourly time steps over a year with randomized load profiles based on utility data and typical meteorological year weather data. For 86% of the cases simulated, maximum PV penetration was at least 30% of peak load.

Hoke, A.; Butler, R.; Hambrick, J.; Kroposki, B.

2012-07-01T23:59:59.000Z

104

Maximum containment : the most controversial labs in the world  

E-Print Network [OSTI]

In 2002, following the September 11th attacks and the anthrax letters, the United States allocated money to build two maximum containment biology labs. Called Biosafety Level 4 (BSL-4) facilities, these labs were built to ...

Bruzek, Alison K. (Allison Kim)

2013-01-01T23:59:59.000Z

105

Multichannel Blind Identification: From Subspace to Maximum Likelihood Methods  

E-Print Network [OSTI]

Multichannel Blind Identification: From Subspace to Maximum Likelihood Methods LANG TONG, MEMBER, IEEE, AND SYLVIE PERREAU Invited Paper A review of recent blind channel estimation algorithms is pre-- Blind equalization, parameter estimation, system identification. I. INTRODUCTION A. What Is Blind

Tong, Lang

106

Multi-Class Classification with Maximum Margin Multiple Kernel  

E-Print Network [OSTI]

(named OBSCURE and UFO-MKL, respectively) are used to optimize primal versions of equivalent problems), the OBSCURE and UFO-MKL algorithms are compared against MCMKL #12;Multi-Class Classification with Maximum

Tomkins, Andrew

107

Maximum entropy method and oscillations in the diffraction cone  

E-Print Network [OSTI]

The maximum entropy method has been applied to investigate the oscillating structure in the pbarp- and pp-elastic scattering differential cross-section at high energy and small momentum transfer. Oscillations satisfying quite realistic reliability criteria have been found.

O. Dumbrajs; J. Kontros; A. Lengyel

2000-07-15T23:59:59.000Z

108

The Galex Ultraviolet Variability (GUVV) Catalog  

E-Print Network [OSTI]

We present Version 1.0 of the NASA Galaxy Evolution Explorer (GALEX) ultraviolet variability catalog (GUVV) that contains information on 84 time-variable and transient sources gained with simultaneous near and far ultraviolet photometric observations. These time-variable sources were serendipitously revealed in the various 1.2 degree star fields currently being surveyed by the GALEX satellite in two ultraviolet bands (NUV 1750-2750A, FUV 1350-1750A) with limiting AB magnitudes of 23-25. The largest-amplitude variable objects presently detected by GALEX are M-dwarf flare stars, which can brighten by 5-10 mag in both the NUV and FUV bands during short duration (< 500s) outbursts. Other types of large-amplitude ultraviolet variable objects include ab-type RR Lyrae stars, which can vary periodically by 2-5mag in the GALEX FUV band. This first GUVV catalog lists galactic positions and possible source identifications in order to provide the astronomical community with a list of time-variable objects that can now be repeatedly observed at other wavelengths. We expect the total number of time-variable source detections to increase as the GALEX mission progresses, such that later version numbers of the GUVV catalog will contain substantially more variable sources.

Barry Y. Welsh; Jonathan M. Wheatley; Kenneth Heafield; Mark Seibert; Stanley E. Browne; Samir Salim; R. Michael Rich; Tom A. Barlow; Luciana Bianchi; Yong-Ik Byun; Jose Donas; Karl Forster; Peter G. Friedman; Timothy M. Heckman; Patrick N. Jelinsky; Young-Wook Lee; Barry F. Madore; Roger F. Malina; D. Christopher Martin; Bruno Milliard; Patrick Morrissey; Susan G. Neff; David Schiminovich; Oswald H. W. Siegmund; Todd Small; Alex S. Szalay; Ted K. Wyder

2005-04-21T23:59:59.000Z

109

Efficiency at maximum power of interacting molecular machines  

E-Print Network [OSTI]

We investigate the efficiency of systems of molecular motors operating at maximum power. We consider two models of kinesin motors on a microtubule: for both the simplified and the detailed model, we find that the many-body exclusion effect enhances the efficiency at maximum power of the many-motor system, with respect to the single motor case. Remarkably, we find that this effect occurs in a limited region of the system parameters, compatible with the biologically relevant range.

N. Golubeva; A. Imparato

2012-10-22T23:59:59.000Z

110

Filtering Additive Measurement Noise with Maximum Entropy in the Mean  

E-Print Network [OSTI]

The purpose of this note is to show how the method of maximum entropy in the mean (MEM) may be used to improve parametric estimation when the measurements are corrupted by large level of noise. The method is developed in the context on a concrete example: that of estimation of the parameter in an exponential distribution. We compare the performance of our method with the bayesian and maximum likelihood approaches.

Henryk Gzyl; Enrique ter Horst

2007-09-04T23:59:59.000Z

111

The maximum entropy tecniques and the statistical description of systems  

E-Print Network [OSTI]

The maximum entropy technique (MENT) is used to determine the distribution functions of physical values. MENT naturally combines required maximum entropy, the properties of a system and connection conditions in the form of restrictions imposed on the system. It can, therefore, be employed to statistically describe closed and open systems. Examples in which MENT is used to describe equilibrium and non-equilibrium states, as well as steady states that are far from being in thermodynamic equilibrium, are discussed.

B. Z. Belashev; M. K. Suleymanov

2001-10-19T23:59:59.000Z

112

Stochastic Search with an Observable State Variable Lauren A. Hannah  

E-Print Network [OSTI]

is an example: a wind farm manager must pledge how much energy she will provide to a utility company an hour, the difference is lost. The objective function depends on the future wind and market price, both unknown. The last 24 hours of wind and market prices, time of day and time of year all contain information about

Powell, Warren B.

113

Field observations of soil moisture variability across scales  

E-Print Network [OSTI]

campaigns were conducted in Oklahoma and Iowa in the centralUSA. The Oklahoma study region is sub-humid with moderatelyUSA South Dakota, USA Oklahoma, USA Kansas, USA Texas, USA

Famiglietti, James S; Ryu, Dongryeol; Berg, Aaron A; Rodell, Matthew; Jackson, Thomas J

2008-01-01T23:59:59.000Z

114

Observed Global Precipitation Variability During the 20th Century  

E-Print Network [OSTI]

of warming and other regional-scale features, including changes in wind patterns, precipitation and some aspects of extremes and of ice. n The models used in AR4 were judged to have improved representation

Anisimov, Mikhail

115

Efficiency of autonomous soft nano-machines at maximum power  

E-Print Network [OSTI]

We consider nano-sized artificial or biological machines working in steady state enforced by imposing non-equilibrium concentrations of solutes or by applying external forces, torques or electric fields. For unicyclic and strongly coupled multicyclic machines, efficiency at maximum power is not bounded by the linear response value 1/2. For strong driving, it can even approach the thermodynamic limit 1. Quite generally, such machines fall in three different classes characterized, respectively, as "strong and efficient", "strong and inefficient", and "balanced". For weakly coupled multicyclic machines, efficiency at maximum power has lost any universality even in the linear response regime.

Udo Seifert

2010-11-11T23:59:59.000Z

116

Assessing complexity by means of maximum entropy models  

E-Print Network [OSTI]

We discuss a characterization of complexity based on successive approximations of the probability density describing a system by means of maximum entropy methods, thereby quantifying the respective role played by different orders of interaction. This characterization is applied on simple cellular automata in order to put it in perspective with the usual notion of complexity for such systems based on Wolfram classes. The overlap is shown to be good, but not perfect. This suggests that complexity in the sense of Wolfram emerges as an intermediate regime of maximum entropy-based complexity, but also gives insights regarding the role of initial conditions in complexity-related issues.

Chliamovitch, Gregor; Velasquez, Lino

2014-01-01T23:59:59.000Z

117

Understanding Biomass Feedstock Variability  

SciTech Connect (OSTI)

If the singular goal of biomass logistics and the design of biomass feedstock supply systems is to reduce the per ton supply cost of biomass, these systems may very well develop with ultimate unintended consequences of highly variable and reduced quality biomass feedstocks. This paper demonstrates that due to inherent species variabilities, production conditions, and differing harvest, collection, and storage practices, this is a very real scenario that biomass producers and suppliers as well as conversion developers should be aware of. Biomass feedstock attributes of ash, carbohydrates, moisture, and particle morphology will be discussed. We will also discuss specifications for these attributes, inherent variability of these attributes in biomass feedstocks, and approaches and solutions for reducing variability for improving feedstock quality.

Kevin L. Kenney; William A. Smith; Garold L. Gresham; Tyler L. Westover

2013-01-01T23:59:59.000Z

118

Understanding Biomass Feedstock Variability  

SciTech Connect (OSTI)

If the singular goal of biomass logistics and the design of biomass feedstock supply systems is to reduce the per-ton supply cost of biomass, these systems may very well develop with ultimate unintended consequences of highly variable and reduced quality biomass feedstocks. This paper demonstrates that, due to inherent species variabilities, production conditions and differing harvest, collection and storage practices, this is a very real scenario that biomass producers and suppliers as well as conversion developers should be aware of. Biomass feedstock attributes of ash, carbohydrates, moisture and particle morphology will be discussed. We will also discuss specifications for these attributes, inherent variability of these attributes in biomass feedstocks, and approaches and solutions for reducing variability for improving feedstock quality.

Kevin L. Kenney; Garold L. Gresham; William A. Smith; Tyler L. Westover

2013-01-01T23:59:59.000Z

119

Maximum-principle-satisfying and positivity-preserving high order ...  

E-Print Network [OSTI]

conservation laws: Survey and new developments ..... Notice that in (2.10) we need to evaluate the maximum/minimum of a ..... total energy, p is the pressure, e is the internal energy, and ? > 1 is a constant ... under a standard CFL condition.

2011-04-01T23:59:59.000Z

120

Maximum Entropy in Support of Semantically Annotated Datasets  

E-Print Network [OSTI]

Maximum Entropy in Support of Semantically Annotated Datasets Paulo Pinheiro da Silva, Vladik whether two datasets describe the same quantity. The existing solution to this problem is to use these datasets' ontologies to deduce that these datasets indeed represent the same quantity. However, even when

Kreinovich, Vladik

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Performance of Civil Aviation Receivers during Maximum Solar Activity Events  

E-Print Network [OSTI]

Performance of Civil Aviation Receivers during Maximum Solar Activity Events Lina DEAMBROGIO on the fields of ionosphere scintillations, solar energetic particles and on the implementation of operational the upcoming period of high solar activity. Emilien ROBERT got his PhD in 2005 and started to work on behalf

Boyer, Edmond

122

Rapidly Solving an Online Sequence of Maximum Flow Problems  

E-Print Network [OSTI]

... an interdictor allocates a finite amount of resources to remove arcs from a net- ... is, the next maximum flow problem in the sequence differs from the previous one by ..... the appropriate reoptimization case and then taking the appropriate action to ..... Our first set of computational experiments tested the performance of our...

2008-02-29T23:59:59.000Z

123

THE MAXIMUM CAPACITY OF A LINE PLAN IS INAPPROXIMABLE  

E-Print Network [OSTI]

THE MAXIMUM CAPACITY OF A LINE PLAN IS INAPPROXIMABLE CHRISTINA PUHL AND SEBASTIAN STILLER Abstract a network, upper arc-capacities and a line pool. E-mail: puhl@math.tu-berlin.de, stiller of the European Commission under contract no. FP6-021235-2. 1 #12;2 CHRISTINA PUHL AND SEBASTIAN STILLER We

Nabben, Reinhard

124

O(1)-Approximations for Maximum Movement Piotr Berman1  

E-Print Network [OSTI]

movement of the pebbles, motivated by minimizing either execution time or energy usage. Spe- cific problems the maximum movement made by pebbles on a graph to reach a configuration in which the pebbles form a connected. For example, in the connectivity goal, the proximity of the robots should form a connected graph. Two

Demaine, Erik

125

Maximization of Recursive Utilities: A Dynamic Maximum Principle Approach  

E-Print Network [OSTI]

Maximization of Recursive Utilities: A Dynamic Maximum Principle Approach Wahid FAIDI LAMSIN, ENIT for a class of robust utility function introduced in Bordigoni, Matoussi et Schweizer (2005). Our method-investment strategy which is characterized as the unique solution of a forward-backward system. Key words : Utility

Di Girolami, Cristina

126

Maximum likelihood estimation of the equity Efstathios Avdis  

E-Print Network [OSTI]

premium is usually estimated by taking the sample mean of stock returns and subtracting a measure the expected return on the aggregate stock market less the government bill rate, is of central importance an alternative esti- mator, based on maximum likelihood, that takes into account informa- tion contained

Kahana, Michael J.

127

Renewable Energy Scheduling for Fading Channels with Maximum Power Constraint  

E-Print Network [OSTI]

Renewable Energy Scheduling for Fading Channels with Maximum Power Constraint Zhe Wang Electrical--In this paper, we develop efficient algorithm to obtain the optimal energy schedule for fading channel with energy harvesting. We assume that the side information of both the channel states and energy harvesting

Greenberg, Albert

128

Retrocommissioning Case Study - Applying Building Selection Criteria for Maximum Results  

E-Print Network [OSTI]

RETROCOMMISSIONING CASE STUDY ?Applying Building Selection Criteria for Maximum Results? Larry Luskay, Tudi Haasl, Linda Irvine Portland Energy Conservation, Inc. Portland, Oregon Donald Frey Architectural Energy Corporation Boulder.... The building was retrocommissioned by Portland Energy Conservation, Inc. (PECI), in conjunction with Architectural Energy Corporation (AEC). The building-specific goals were: 1) Obtain cost-effective energy savings from optimizing operation...

Luskay, L.; Haasl, T.; Irvine, L.; Frey, D.

2002-01-01T23:59:59.000Z

129

How multiplicity determines entropy and the derivation of the maximum entropy principle for complex systems  

E-Print Network [OSTI]

The maximum entropy principle (MEP) is a method for obtaining the most likely distribution functions of observables from statistical systems, by maximizing entropy under constraints. The MEP has found hundreds of applications in ergodic and Markovian systems in statistical mechanics, information theory, and statistics. For several decades there exists an ongoing controversy whether the notion of the maximum entropy principle can be extended in a meaningful way to non-extensive, non-ergodic, and complex statistical systems and processes. In this paper we start by reviewing how Boltzmann-Gibbs-Shannon entropy is related to multiplicities of independent random processes. We then show how the relaxation of independence naturally leads to the most general entropies that are compatible with the first three Shannon-Khinchin axioms, the (c,d)-entropies. We demonstrate that the MEP is a perfectly consistent concept for non-ergodic and complex statistical systems if their relative entropy can be factored into a general...

Hanel, Rudolf; Gell-Mann, Murray

2014-01-01T23:59:59.000Z

130

Exact computation of the Maximum Entropy Potential of spiking neural networks models  

E-Print Network [OSTI]

Understanding how stimuli and synaptic connectivity in uence the statistics of spike patterns in neural networks is a central question in computational neuroscience. Maximum Entropy approach has been successfully used to characterize the statistical response of simultaneously recorded spiking neurons responding to stimuli. But, in spite of good performance in terms of prediction, the ?tting parameters do not explain the underlying mechanistic causes of the observed correlations. On the other hand, mathematical models of spiking neurons (neuro-mimetic models) provide a probabilistic mapping between stimulus, network architecture and spike patterns in terms of conditional proba- bilities. In this paper we build an exact analytical mapping between neuro-mimetic and Maximum Entropy models.

Cofre, Rodrigo

2014-01-01T23:59:59.000Z

131

Maximum Entropy Principle and the Higgs Boson Mass  

E-Print Network [OSTI]

A successful connection between Higgs boson decays and the Maximum Entropy Principle is presented. Based on the information theory inference approach we determine the Higgs boson mass as $M_H= 125.04\\pm 0.25$ GeV, a value fully compatible to the LHC measurement. This is straightforwardly obtained by taking the Higgs boson branching ratios as the target probability distributions of the inference, without any extra assumptions beyond the Standard Model. Yet, the principle can be a powerful tool in the construction of any model affecting the Higgs sector. We give, as an example, the case where the Higgs boson has an extra invisible decay channel. Our findings suggest that a system of Higgs bosons undergoing a collective decay to Standard Model particles is among the most fundamental ones where the Maximum Entropy Principle applies.

Alves, Alexandre; da Silva, Roberto

2014-01-01T23:59:59.000Z

132

Maximum Entropy Principle and the Higgs Boson Mass  

E-Print Network [OSTI]

A successful connection between Higgs boson decays and the Maximum Entropy Principle is presented. Based on the information theory inference approach we determine the Higgs boson mass as $M_H= 125.04\\pm 0.25$ GeV, a value fully compatible to the LHC measurement. This is straightforwardly obtained by taking the Higgs boson branching ratios as the target probability distributions of the inference, without any extra assumptions beyond the Standard Model. Yet, the principle can be a powerful tool in the construction of any model affecting the Higgs sector. We give, as an example, the case where the Higgs boson has an extra invisible decay channel. Our findings suggest that a system of Higgs bosons undergoing a collective decay to Standard Model particles is among the most fundamental ones where the Maximum Entropy Principle applies.

Alexandre Alves; Alex G. Dias; Roberto da Silva

2014-11-18T23:59:59.000Z

133

GEOPHYSICAL RESEARCH LETTERS, VOL. ???, XXXX, DOI:10.1029/, Destruction of the Tertiary Ozone Maximum During a Solar  

E-Print Network [OSTI]

Maximum During a Solar Proton Event A. Sepp¨al¨a, P. T. Verronen, V. F. Sofieva, J. Tamminen, E. Kyr¨ol¨a Finnish Meteorological Institute, Earth Observation, Helsinki, Finland C. J. Rodger Physics Department to study the effects of the January 2005 solar storms on the polar winter middle atmosphere. The model

Otago, University of

134

Analysis to determine the maximum dimensions of flexible apertures in sensored security netting products.  

SciTech Connect (OSTI)

Although technological advances provide new capabilities to increase the robustness of security systems, they also potentially introduce new vulnerabilities. New capability sometimes requires new performance requirements. This paper outlines an approach to establishing a key performance requirement for an emerging intrusion detection sensor: the sensored net. Throughout the security industry, the commonly adopted standard for maximum opening size through barriers is a requirement based on square inches-typically 96 square inches. Unlike standard rigid opening, the dimensions of a flexible aperture are not fixed, but variable and conformable. It is demonstrably simple for a human intruder to move through a 96-square-inch opening that is conformable to the human body. The longstanding 96-square-inch requirement itself, though firmly embedded in policy and best practice, lacks a documented empirical basis. This analysis concluded that the traditional 96-square-inch standard for openings is insufficient for flexible openings that are conformable to the human body. Instead, a circumference standard is recommended for these newer types of sensored barriers. The recommended maximum circumference for a flexible opening should be no more than 26 inches, as measured on the inside of the netting material.

Murton, Mark; Bouchier, Francis A.; vanDongen, Dale T.; Mack, Thomas Kimball; Cutler, Robert Paul; Ross, Michael P.

2013-08-01T23:59:59.000Z

135

Maximum Entry and Mandatory Separation Ages for Certain Security Employees  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

The policy establishes the DOE policy on maximum entry and mandatory separation ages for primary or secondary positions covered under special statutory retirement provisions and for those employees whose primary duties are the protection of officials of the United States against threats to personal safety or the investigation, apprehension, and detention of individuals suspected or convicted of offenses against the criminal laws of the United States. Admin Chg 1, dated 12-1-11, cancels DOE P 310.1.

2001-10-11T23:59:59.000Z

136

Occam's Razor Cuts Away the Maximum Entropy Principle  

E-Print Network [OSTI]

I show that the maximum entropy principle can be replaced by a more natural assumption, that there exists a phenomenological function of entropy consistent with the microscopic model. The requirement of existence provides then a unique construction of the related probability density. I conclude the letter with an axiomatic formulation of the notion of entropy, which is suitable for exploration of the non-equilibrium phenomena.

Rudnicki, ?ukasz

2014-01-01T23:59:59.000Z

137

PNNL: A Supervised Maximum Entropy Approach to Word Sense Disambiguation  

SciTech Connect (OSTI)

In this paper, we described the PNNL Word Sense Disambiguation system as applied to the English All-Word task in Se-mEval 2007. We use a supervised learning approach, employing a large number of features and using Information Gain for dimension reduction. Our Maximum Entropy approach combined with a rich set of features produced results that are significantly better than baseline and are the highest F-score for the fined-grained English All-Words subtask.

Tratz, Stephen C.; Sanfilippo, Antonio P.; Gregory, Michelle L.; Chappell, Alan R.; Posse, Christian; Whitney, Paul D.

2007-06-23T23:59:59.000Z

138

Some interesting consequences of the maximum entropy production principle  

SciTech Connect (OSTI)

Two nonequilibrium phase transitions (morphological and hydrodynamic) are analyzed by applying the maximum entropy production principle. Quantitative analysis is for the first time compared with experiment. Nonequilibrium crystallization of ice and laminar-turbulent flow transition in a circular pipe are examined as examples of morphological and hydrodynamic transitions, respectively. For the latter transition, a minimum critical Reynolds number of 1200 is predicted. A discussion of this important and interesting result is presented.

Martyushev, L. M. [Russian Academy of Sciences, Institute of Industrial Ecology, Ural Division (Russian Federation)], E-mail: mlm@ecko.uran.ru

2007-04-15T23:59:59.000Z

139

Variable Frequency Pump Drives  

E-Print Network [OSTI]

-frequency electric motor drive. What is happenin9 with variable frequency driven pun,ps is a classical illustration that evolution in technical products takes place not only because of changes in the processes served by these products, or because of innovations...-pole 3550 rpm squirrel caqe induction motor became available in the early 1930s that high pressure pumps operating at that speed could be buil t. And now, in the 1980s, the development of the solid-state, variable frequency electric motor drive...

Karassik, I. J.; Petraccaro, L. L.; McGuire, J. T.

140

Total Solar Irradiance Variability and the Solar Activity Cycle  

E-Print Network [OSTI]

It is suggested that the solar variability is due to the perturbed nature of the solar core and this variability is provided by the variability of the solar neutrino flux from the solar neutrino detectors i.e., Homestake, Superkamiokande, SAGE and GALLEX-GNO. The solar neutrino flux in the standard solar model (SSM) was calculated on the assumption of L_nu (neutrino luminosity) = L_gamma (optical luminosity) which implies that if there is a change in optical luminosity then solar neutrino flux data will also be changed. An internal dynamo due to the cyclic variation of nuclear energy generation inside the core of the sun is responsible for the solar activity cycle was suggested and thus the internal magnetic field is also variable. Again the changes in the nuclear energy generation induce structural changes that result in variations of the global solar parameters i.e., luminosity, radius and temperatures etc. From the analysis of total solar irradiance (TSI) data during the year from 1970 to 2003 we have found five phases within the solar activity cycle. The first phase (I) starts before two years from the sunspot minimum. The second phase (II) starts at the time of sunspot minimum and phase (III) starts before 2/3 years from sunspot maximum whereas phase (IV) starts at sunspot maximum and fifth phase (V) starts at after 2-3 years from sunspot maximum.

Probhas Raychaudhuri

2006-05-06T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Beyond Boltzmann-Gibbs statistics: Maximum entropy hyperensembles out-of-equilibrium  

E-Print Network [OSTI]

1957). J. Skilling, in Maximum Entropy and Bayesian Methods,4552. J. Skilling, in Maximum Entropy and Bayesian Methods,e C. C. Rodriguez, in Maximum Entropy and Bayesian Methods,

Crooks, Gavin E.

2006-01-01T23:59:59.000Z

142

Deriving the continuity of maximum-entropy basis functions via variational analysis  

E-Print Network [OSTI]

and V. J. DellaPietra, A maximum entropy approach to naturalJ. and R. K. Bryan, Maximum entropy image reconstruction:Heidelberg, Continuity of maximum-entropy basis functions p

Sukumar, N.; Wets, R. J. -B.

2007-01-01T23:59:59.000Z

143

BRANCH-CUT-AND-PROPAGATE FOR THE MAXIMUM k ...  

E-Print Network [OSTI]

handling of graph symmetries yields a significant performance speed-up. 1. Introduction .... A symmetry of an IP is a permutation of the variables that maps feasible .... Thus, we only consider the generators of Aut(G) that ...... In Operations Re-.

2011-03-16T23:59:59.000Z

144

The Hybrid Maximum Principle is a consequence of Pontryagin ...  

E-Print Network [OSTI]

is not fixed, the set U = [0,1], the functions g1, g2, ? are positive and differentiable in R1. The car starts from the point (x0,y0) = (0,0) and the state variables x and.

2006-10-31T23:59:59.000Z

145

Long-term spectroscopic monitoring of the Luminous Blue Variable HD160529  

E-Print Network [OSTI]

We have spectroscopically monitored the galactic Luminous Blue Variable HD 160529 and obtained an extensive high-resolution data set that covers the years 1991 to 2002. During this period, the star evolved from an extended photometric minimum phase towards a new visual maximum. In several observing seasons, we covered up to four months with almost daily spectra. Our spectra typically cover most of the visual spectral range with a high spectral resolution (about 20,000 or more). This allows us to investigate the variability in many lines and on many time scales from days to years. We find a correlation between the photospheric HeI lines and the brightness of the star, both on a time scale of months and on a time scale of years. The short-term variations are smaller and do not follow the long-term trend, strongly suggesting different physical mechanisms. Metal lines also show both short-term and long-term variations in strength and also a long-term trend in radial velocity. Most of the line-profile variations can be attributed to changing strengths of lines. Propagating features in the line profiles are rarely observed. We find that the mass-loss rate of HD 160529 is almost independent of temperature, i.e. visual brightness.

Otmar Stahl; Thomas Gaeng; Chris Sterken; Andreas Kaufer; Thomas Rivinius; Thomas Szeifert; Bernhard Wolf

2002-12-20T23:59:59.000Z

146

X-Ray Luminosity and Spectral Variability in the TEV BL Lac 1ES2344+514  

E-Print Network [OSTI]

The results of a series of five \\sax observations of the TeV BL Lac object 1ES2344+514 are briefly presented. Large amplitude luminosity variability, associated to impressive spectral changes in the hard X-rays, have been found. The shape of the lightcurve depends on energy, with the flare starting and ending in the hard band, but with maximum intensity possibly reached earlier in the soft X-rays. The luminosity and spectral changes may be due to a shift of the peak of the synchrotron emission from the soft X-rays to the hard X-ray band similar to that detected during \\sax observations of MKN 501.

P. Giommi; P. Padovani; E. Perlman

1998-02-02T23:59:59.000Z

147

A New Luminous Blue Variable in M31  

E-Print Network [OSTI]

We report the fifth confirmed Luminous Blue Variable/S Doradus variable in M31. In 2006, J004526.62+415006.3 had the spectrum of hot Fe II emission line star with strong P Cygni profiles in the Balmer lines. In 2010, its absorption line spectrum resembled an early A-type supergiant with H and Fe II emission lines with strong P Cygni profiles, and in 2013 the spectrum had fully transitioned to an F-type supergiant due to the formation of the optically thick, cool wind which characterizes LBVs at maximum light. The photometric record supports the LBV/S Dor nature of the variability. Its bolometric luminosity ~ -9.65 mag places it on the HR Diagram near the known LBVs, AE And, Var C in M33 and S Dor.

Humphreys, Roberta M; Gordon, Michael S

2015-01-01T23:59:59.000Z

148

Better Nonlinear Models from Noisy Data: Attractors with Maximum Likelihood  

E-Print Network [OSTI]

A new approach to nonlinear modelling is presented which, by incorporating the global behaviour of the model, lifts shortcomings of both least squares and total least squares parameter estimates. Although ubiquitous in practice, a least squares approach is fundamentally flawed in that it assumes independent, normally distributed (IND) forecast errors: nonlinear models will not yield IND errors even if the noise is IND. A new cost function is obtained via the maximum likelihood principle; superior results are illustrated both for small data sets and infinitely long data streams.

Patrick E. McSharry; Leonard A. Smith

1999-11-30T23:59:59.000Z

149

Application of Maximum Entropy Method to Dynamical Fermions  

E-Print Network [OSTI]

The Maximum Entropy Method is applied to dynamical fermion simulations of the (2+1)-dimensional Nambu-Jona-Lasinio model. This model is particularly interesting because at T=0 it has a broken phase with a rich spectrum of mesonic bound states and a symmetric phase where there are resonances, and hence the simple pole assumption of traditional fitting procedures breaks down. We present results extracted from simulations on large lattices for the spectral functions of the elementary fermion, the pion, the sigma, the massive pseudoscalar meson and the symmetric phase resonances.

Jonathan Clowser; Costas Strouthos

2001-10-16T23:59:59.000Z

150

Improving predictability of time series using maximum entropy methods  

E-Print Network [OSTI]

We discuss how maximum entropy methods may be applied to the reconstruction of Markov processes underlying empirical time series and compare this approach to usual frequency sampling. It is shown that, at least in low dimension, there exists a subset of the space of stochastic matrices for which the MaxEnt method is more efficient than sampling, in the sense that shorter historical samples have to be considered to reach the same accuracy. Considering short samples is of particular interest when modelling smoothly non-stationary processes, for then it provides, under some conditions, a powerful forecasting tool. The method is illustrated for a discretized empirical series of exchange rates.

Gregor Chliamovitch; Alexandre Dupuis; Bastien Chopard; Anton Golub

2014-11-28T23:59:59.000Z

151

Reducing Degeneracy in Maximum Entropy Models of Networks  

E-Print Network [OSTI]

Based on Jaynes's maximum entropy principle, exponential random graphs provide a family of principled models that allow the prediction of network properties as constrained by empirical data. However, their use is often hindered by the degeneracy problem characterized by spontaneous symmetry-breaking, where predictions simply fail. Here we show that degeneracy appears when the corresponding density of states function is not log-concave. We propose a solution to the degeneracy problem for a large class of models by exploiting the nonlinear relationships between the constrained measures to convexify the domain of the density of states. We demonstrate the effectiveness of the method on examples, including on Zachary's karate club network data.

Horvt, Szabolcs; Toroczkai, Zoltn

2014-01-01T23:59:59.000Z

152

Improving predictability of time series using maximum entropy methods  

E-Print Network [OSTI]

We discuss how maximum entropy methods may be applied to the reconstruction of Markov processes underlying empirical time series and compare this approach to usual frequency sampling. It is shown that, at least in low dimension, there exists a subset of the space of stochastic matrices for which the MaxEnt method is more efficient than sampling, in the sense that shorter historical samples have to be considered to reach the same accuracy. Considering short samples is of particular interest when modelling smoothly non-stationary processes, for then it provides, under some conditions, a powerful forecasting tool. The method is illustrated for a discretized empirical series of exchange rates.

Chliamovitch, Gregor; Chopard, Bastien; Golub, Anton

2014-01-01T23:59:59.000Z

153

Excited nucleon spectrum from lattice QCD with maximum entropy method  

E-Print Network [OSTI]

We study excited states of the nucleon in quenched lattice QCD with the spectral analysis using the maximum entropy method. Our simulations are performed on three lattice sizes $16^3\\times 32$, $24^3\\times 32$ and $32^3\\times 32$, at $\\beta=6.0$ to address the finite volume issue. We find a significant finite volume effect on the mass of the Roper resonance for light quark masses. After removing this systematic error, its mass becomes considerably reduced toward the direction to solve the level order puzzle between the Roper resonance $N'(1440)$ and the negative-parity nucleon $N^*(1535)$.

K. Sasaki; S. Sasaki; T. Hatsuda; M. Asakawa

2003-09-29T23:59:59.000Z

154

Variable Crop Share Leases.  

E-Print Network [OSTI]

)OC lAL45.7 173 1. 1224 Texas Agricultural Extension Service The Texas A&M University System Daniel C. Pfannstiel,Director colleg e Station, Texas / f , ' '~ :';,; ,,: ''': ~ " k , -~. _Variable _Crop Share _Leases ... Marvin... Sartin and Ray Sammons* Renting or leasing farmland is part of many modern farming operations and increases average farm size in U. S. agriculture. Economies of size are vitally import ant to farm operations as they strive to cope with the continuous...

Sartin, Marvin; Sammons, Ray

1980-01-01T23:59:59.000Z

155

Variable depth core sampler  

DOE Patents [OSTI]

A variable depth core sampler apparatus is described comprising a first circular hole saw member, having longitudinal sections that collapses to form a point and capture a sample, and a second circular hole saw member residing inside said first hole saw member to support the longitudinal sections of said first hole saw member and prevent them from collapsing to form a point. The second hole saw member may be raised and lowered inside said first hole saw member. 7 figs.

Bourgeois, P.M.; Reger, R.J.

1996-02-20T23:59:59.000Z

156

Ionization and maximum energy of nuclei in shock acceleration theory  

E-Print Network [OSTI]

We study the acceleration of heavy nuclei at SNR shocks when the process of ionization is taken into account. Heavy atoms ($Z_N >$ few) in the interstellar medium which start the diffusive shock acceleration (DSA) are never fully ionized at the moment of injection. The ionization occurs during the acceleration process, when atoms already move relativistically. For typical environment around SNRs the photo-ionization due to the background galactic radiation dominates over Coulomb collisions. The main consequence of ionization is the reduction of the maximum energy which ions can achieve with respect to the standard result of the DSA. In fact the photo-ionization has a timescale comparable to the beginning of the Sedov-Taylor phase, hence the maximum energy is no more proportional to the nuclear charge, as predicted by standard DSA, but rather to the effective ions' charge during the acceleration process, which is smaller than the total nuclear charge $Z_N$. This result can have a direct consequence in the pred...

Morlino, Giovanni

2011-01-01T23:59:59.000Z

157

Maximum surface level and temperature histories for Hanford waste tanks  

SciTech Connect (OSTI)

Radioactive defense waste resulting from the chemical processing of spent nuclear fuel has been accumulating at the Hanford Site since 1944. This waste is stored in underground waste-storage tanks. The Hanford Site Tank Farm Facilities Interim Safety Basis (ISB) provides a ready reference to the safety envelope for applicable tank farm facilities and installations. During preparation of the ISB, tank structural integrity concerns were identified as a key element in defining the safety envelope. These concerns, along with several deficiencies in the technical bases associated with the structural integrity issues and the corresponding operational limits/controls specified for conduct of normal tank farm operations are documented in the ISB. Consequently, a plan was initiated to upgrade the safety envelope technical bases by conducting Accelerated Safety Analyses-Phase 1 (ASA-Phase 1) sensitivity studies and additional structural evaluations. The purpose of this report is to facilitate the ASA-Phase 1 studies and future analyses of the single-shell tanks (SSTs) and double-shell tanks (DSTs) by compiling a quantitative summary of some of the past operating conditions the tanks have experienced during their existence. This report documents the available summaries of recorded maximum surface levels and maximum waste temperatures and references other sources for more specific data.

Flanagan, B.D.; Ha, N.D.; Huisingh, J.S.

1994-09-02T23:59:59.000Z

158

A variable-field permanent-magnet dipole for accelerators  

SciTech Connect (OSTI)

A new concept for a variable-field permanent-magnet dipole has been developed and fabricated at Los Alamos. The application requires an extremely uniform dipole field in the magnet aperture and precision variability over a large operating range. An iron-core permanent- magnet design using a shunt that was specially shaped to vary the field in a precise and reproducible fashion with shunt position. The key to this design is in the shape of the shunt. The field as a function of shunt position is very linear from 90% of the maximum field to 20% of the minimum field. The shaped shunt also results in a small maximum magnetic force attracting the shunt to the yoke allowing a simple mechanical design. Calculated and measured results agree well for the magnet.

Kraus, R.H. Jr.; Barlow, D.B.; Meyer, R.

1992-01-01T23:59:59.000Z

159

A variable-field permanent-magnet dipole for accelerators  

SciTech Connect (OSTI)

A new concept for a variable-field permanent-magnet dipole has been developed and fabricated at Los Alamos. The application requires an extremely uniform dipole field in the magnet aperture and precision variability over a large operating range. An iron-core permanent- magnet design using a shunt that was specially shaped to vary the field in a precise and reproducible fashion with shunt position. The key to this design is in the shape of the shunt. The field as a function of shunt position is very linear from 90% of the maximum field to 20% of the minimum field. The shaped shunt also results in a small maximum magnetic force attracting the shunt to the yoke allowing a simple mechanical design. Calculated and measured results agree well for the magnet.

Kraus, R.H. Jr.; Barlow, D.B.; Meyer, R.

1992-09-01T23:59:59.000Z

160

Reduction of tropical land region precipitation variability via transpiration  

E-Print Network [OSTI]

Tropical rainforests are known to exhibit low intraseasonal precipitation variability compared with oceanic areas with similar mean precipitation in observations and models. In the present study, the potential role of ...

Lee, Jung-Eun

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Reduction in maximum time uncertainty of paired time signals  

DOE Patents [OSTI]

Reduction in the maximum time uncertainty (t/sub max/ - t/sub min/) of a series of paired time signals t/sub 1/ and t/sub 2/ varying between two input terminals and representative of a series of single events where t/sub 1/ less than or equal to t/sub 2/ and t/sub 1/ + t/sub 2/ equals a constant, is carried out with a circuit utilizing a combination of OR and AND gates as signal selecting means and one or more time delays to increase the minimum value (t/sub min/) of the first signal t/sub 1/ closer to t/sub max/ and thereby reduce the difference. The circuit may utilize a plurality of stages to reduce the uncertainty by factors of 20 to 800.

Theodosiou, G.E.; Dawson, J.W.

1981-02-11T23:59:59.000Z

162

Probable maximum flood control; Yucca Mountain Site Characterization Project  

SciTech Connect (OSTI)

This study proposes preliminary design concepts to protect the waste-handling facilities and all shaft and ramp entries to the underground from the probable maximum flood (PMF) in the current design configuration for the proposed Nevada Nuclear Waste Storage Investigation (NNWSI) repository protection provisions were furnished by the United States Bureau of Reclamation (USSR) or developed from USSR data. Proposed flood protection provisions include site grading, drainage channels, and diversion dikes. Figures are provided to show these proposed flood protection provisions at each area investigated. These areas are the central surface facilities (including the waste-handling building and waste treatment building), tuff ramp portal, waste ramp portal, men-and-materials shaft, emplacement exhaust shaft, and exploratory shafts facility.

DeGabriele, C.E.; Wu, C.L. [Bechtel National, Inc., San Francisco, CA (United States)

1991-11-01T23:59:59.000Z

163

Fracture Toughness and Maximum Stress in a Disordered Lattice System  

E-Print Network [OSTI]

Fracture in a disordered lattice system is studied. In our system, particles are initially arranged on the triangular lattice and each nearest-neighbor pair is connected with a randomly chosen soft or hard Hookean spring. Every spring has the common threshold of stress at which it is cut. We make an initial crack and expand the system perpendicularly to the crack. We find that the maximum stress in the stress-strain curve is larger than those in the systems with soft or hard springs only (uniform systems). Energy required to advance fracture is also larger in some disordered systems, which indicates that the fracture toughness improves. The increase of the energy is caused by the following two factors. One is that the soft spring is able to hold larger energy than the hard one. The other is that the number of cut springs increases as the fracture surface becomes tortuous in disordered systems.

Chiyori Urabe; Shinji Takesue

2008-12-29T23:59:59.000Z

164

Maximum Margin Clustering for State Decomposition of Metastable Systems  

E-Print Network [OSTI]

When studying a metastable dynamical system, a prime concern is how to decompose the phase space into a set of metastable states. Unfortunately, the metastable state decomposition based on simulation or experimental data is still a challenge. The most popular and simplest approach is geometric clustering which is developed based on the classical clustering technique. However, the prerequisites of this approach are: (1) data are obtained from simulations or experiments which are in global equilibrium and (2) the coordinate system is appropriately selected. Recently, the kinetic clustering approach based on phase space discretization and transition probability estimation has drawn much attention due to its applicability to more general cases, but the choice of discretization policy is a difficult task. In this paper, a new decomposition method designated as maximum margin metastable clustering is proposed, which converts the problem of metastable state decomposition to a semi-supervised learning problem so that...

Wu, Hao

2015-01-01T23:59:59.000Z

165

Improved Maximum Entropy Analysis with an Extended Search Space  

E-Print Network [OSTI]

The standard implementation of the Maximum Entropy Method (MEM) follows Bryan and deploys a Singular Value Decomposition (SVD) to limit the dimensionality of the underlying solution space apriori. Here we present arguments based on the shape of the SVD basis functions and numerical evidence from a mock data analysis, which show that the correct Bayesian solution is not in general recovered with this approach. As a remedy we propose to extend the search basis systematically, which will eventually recover the full solution space and the correct solution. In order to adequately approach problems where an exponentially damped kernel is used, we provide an open-source implementation, using the C/C++ language that utilizes high precision arithmetic adjustable at run-time. The LBFGS algorithm is included in the code in order to attack problems without the need to resort to a particular search space restriction.

Alexander Rothkopf

2013-01-07T23:59:59.000Z

166

Quantum maximum entropy principle for a system of identical particles  

SciTech Connect (OSTI)

By introducing a functional of the reduced density matrix, we generalize the definition of a quantum entropy which incorporates the indistinguishability principle of a system of identical particles. With the present definition, the principle of quantum maximum entropy permits us to solve the closure problem for a quantum hydrodynamic set of balance equations corresponding to an arbitrary number of moments in the framework of extended thermodynamics. The determination of the reduced Wigner function for equilibrium and nonequilibrium conditions is found to become possible only by assuming that the Lagrange multipliers can be expanded in powers of (Planck constant/2pi){sup 2}. Quantum contributions are expressed in powers of (Planck constant/2pi){sup 2} while classical results are recovered in the limit (Planck constant/2pi)->0.

Trovato, M. [Dipartimento di Matematica, Universita di Catania, Viale A. Doria, 95125 Catania (Italy); Reggiani, L. [Dipartimento di Ingegneria dell' Innovazione and CNISM, Universita del Salento, Via Arnesano s/n, 73100 Lecce (Italy)

2010-02-15T23:59:59.000Z

167

Detection of Exceptional X-Ray Spectral Variability in the TeV BL Lac 1ES 2344+514  

E-Print Network [OSTI]

We present the results of six BeppoSAX observations of 1ES 2344+514, five of which were taken within a week. 1ES 2344+514, one of the few known TeV BL Lac objects, was detected by the BeppoSAX Narrow Field Instruments between 0.1 to \\~50 keV. During the first five closely spaced observations 1ES 2344+514 showed large amplitude luminosity variability, associated with spectacular spectral changes, particularly when compared to the last observation when the source was found to be several times fainter, with a much steeper X-ray spectrum. The energy dependent shape of the lightcurve and the spectral changes imply a large shift (factor of 30 or more in frequency) of the peak of the synchrotron emission. At maximum flux the peak was located at or above 10 keV, making 1ES 2344+514 the second blazar (after MKN501) with the synchrotron peak in the hard X-ray band. The shift, and the corresponding increase in luminosity, might be due to the onset of a second synchrotron component extending from the soft to the hard X-ray band where most of the power is emitted. Rapid variability on a timescale of approximately 5000 seconds has also been detected when the source was brightest.

P. Giommi; P. Padovani; E. Perlman

1999-07-27T23:59:59.000Z

168

Map-making in small field modulated CMB polarisation experiments: approximating the maximum-likelihood method  

E-Print Network [OSTI]

Map-making presents a significant computational challenge to the next generation of kilopixel CMB polarisation experiments. Years worth of time ordered data (TOD) from thousands of detectors will need to be compressed into maps of the T, Q and U Stokes parameters. Fundamental to the science goal of these experiments, the observation of B-modes, is the ability to control noise and systematics. In this paper, we consider an alternative to the maximum-likelihood method, called destriping, where the noise is modelled as a set of discrete offset functions and then subtracted from the time-stream. We compare our destriping code (Descart: the DEStriping CARTographer) to a full maximum-likelihood map-maker, applying them to 200 Monte-Carlo simulations of time-ordered data from a ground based, partial-sky polarisation modulation experiment. In these simulations, the noise is dominated by either detector or atmospheric 1/f noise. Using prior information of the power spectrum of this noise, we produce destriped maps of T, Q and U which are negligibly different from optimal. The method does not filter the signal or bias the E or B-mode power spectra. Depending on the length of the destriping baseline, the method delivers between 5 and 22 times improvement in computation time over the maximum-likelihood algorithm. We find that, for the specific case of single detector maps, it is essential to destripe the atmospheric 1/f in order to detect B-modes, even though the Q and U signals are modulated by a half-wave plate spinning at 5-Hz.

D. Sutton; B. R. Johnson; M. L. Brown; P. Cabella; P. G. Ferreira; K. M. Smith

2008-07-23T23:59:59.000Z

169

PHP: Constructs and Variables Introduction  

E-Print Network [OSTI]

PHP: Constructs and Variables Introduction This document describes: 1. the syntax and types of variables, 2. PHP control structures (i.e., conditionals and loops), 3. mixed-mode processing, 4. how to use one script from within another, 5. how to define and use functions, 6. global variables in PHP, 7

Vander Zanden, Brad

170

Correlated spectral variability in brown dwarfs  

E-Print Network [OSTI]

Models of brown dwarf atmospheres suggest they exhibit complex physical behaviour. Observations have shown that they are indeed dynamic, displaying small photometric variations over timescales of hours. Here I report results of infrared (0.95-1.64 micron) spectrophotometric monitoring of four field L and T dwarfs spanning timescales of 0.1-5.5 hrs, the goal being to learn more about the physical nature of this variability. Spectra are analysed differentially with respect to a simultaneously observed reference source in order to remove Earth-atmospheric variations. The variability amplitude detected is typically 2-10%, depending on the source and wavelength. I analyse the data for correlated variations between spectral indices. This approach is more robust than single band or chisq analyses, because it does not assume an amplitude for the (often uncertain) noise level (although the significance test still assumes a shape for the noise power spectrum). Three of the four targets show significant evidence for cor...

Bailer-Jones, C A L

2007-01-01T23:59:59.000Z

171

X-ray variability in M87  

E-Print Network [OSTI]

We present the evidence for X-ray variability from the core and from knot A in the M87 jet based on data from two observations with the Einstein Observatory High Resolution Imager (HRI) and three observations with the ROSAT HRI. The core intensity showed a 16% increase in 17 months ('79-'80); a 12% increase in the 3 years '92 to '95; and a 17% drop in the last half of 1995. The intensity of knot A appears to have decreased by 16% between 92Jun and 95Dec. Although the core variability is consistent with general expectations for AGN nuclei, the changes in knot A provide constraints on the x-ray emission process and geometry. Thus we predict that the x-ray morphology of knot A will differ significantly from the radio and optical structure.

D. E. Harris; J. A. Biretta; W. Junor

1996-12-05T23:59:59.000Z

172

Quantifying extrinsic noise in gene expression using the maximum entropy framework  

E-Print Network [OSTI]

We present a maximum entropy framework to separate intrinsic and extrinsic contributions to noisy gene expression solely from the profile of expression. We express the experimentally accessible probability distribution of the copy number of the gene product (mRNA or protein) by accounting for possible variations in extrinsic factors. The distribution of extrinsic factors is estimated using the maximum entropy principle. Our results show that extrinsic factors qualitatively and quantitatively affect the probability distribution of the gene product. We work out, in detail, the transcription of mRNA from a constitutively expressed promoter in {\\it E. coli}. We suggest that the variation in extrinsic factors may account for the observed {\\it wider than Poisson} distribution of mRNA copy numbers. We successfully test our framework on a numerical simulation of a simple gene expression scheme that accounts for the variation in extrinsic factors. We also make falsifiable predictions, some of which are tested on previous experiments in {\\it E. coli} while others need verification. Application of the current framework to more complex situations is also discussed.

Purushottam D. Dixit

2013-04-04T23:59:59.000Z

173

VIII. The observational strategy: What are the issues; What must be done?  

SciTech Connect (OSTI)

Throughout its development, the observational strategy of the Earth Observing System (EOS) and its precursor programs has been consistent with that of the Mission to Planet Earth (MTPE) to detect and quantify climate change, document natural climate variability, understand variation and change, determine the causes and impacts of stratospheric ozone depletion, determine the impact of change on ecosystems and mitigate them. Space based observation can contribute significantly to each of these objectives, although its contribution will have to be carefully integrated with aircraft, in situ, international and other contributions and carefully transitioned to long-term operational observations to achieve its maximum potential impact. The interaction between space ad in situ can be in calibration, in interpretation, or in suggesting ways to make important new measurements from space. In atmospheric chemistry is largely involves calibration and global surveys. In ecosystems it involves calibration of EOS and improved sensors. In seasonal to interannual change it involves the testing and calibration of new sensors. In decadal to century change it requires the invention of new sensors. These roles are complementary and reinforcing. Taking full advantage of the synergisms and tradeoffs between space- and ground-based measurements is a potential vehicle for major savings in what is effectively a constant resource program. This paper presents a discussion of the principles guiding the space-based observational strategy, and the interplay between spaced-based and in situ measurements. The paper then discusses international issues, how they might be addressed, and integrated space-based observational strategy.

Canavan, G.H.

1997-03-01T23:59:59.000Z

174

Savannah River Site radioiodine atmospheric releases and offsite maximum doses  

SciTech Connect (OSTI)

Radioisotopes of iodine have been released to the atmosphere from the Savannah River Site since 1955. The releases, mostly from the 200-F and 200-H Chemical Separations areas, consist of the isotopes, I-129 and 1-131. Small amounts of 1-131 and 1-133 have also been released from reactor facilities and the Savannah River Laboratory. This reference memorandum was issued to summarize our current knowledge of releases of radioiodines and resultant maximum offsite doses. This memorandum supplements the reference memorandum by providing more detailed supporting technical information. Doses reported in this memorandum from consumption of the milk containing the highest I-131 concentration following the 1961 1-131 release incident are about 1% higher than reported in the reference memorandum. This is the result of using unrounded 1-131 concentrations of I-131 in milk in this memo. It is emphasized here that this technical report does not constitute a dose reconstruction in the same sense as the dose reconstruction effort currently underway at Hanford. This report uses existing published data for radioiodine releases and existing transport and dosimetry models.

Marter, W.L.

1990-11-01T23:59:59.000Z

175

LANDFILL OPERATION FOR CARBON SEQUESTRATION AND MAXIMUM METHANE EMISSION CONTROL  

SciTech Connect (OSTI)

The work described in this report, to demonstrate and advance this technology, has used two demonstration-scale cells of size (8000 metric tons [tonnes]), sufficient to replicate many heat and compaction characteristics of larger ''full-scale'' landfills. An enhanced demonstration cell has received moisture supplementation to field capacity. This is the maximum moisture waste can hold while still limiting liquid drainage rate to minimal and safely manageable levels. The enhanced landfill module was compared to a parallel control landfill module receiving no moisture additions. Gas recovery has continued for a period of over 4 years. It is quite encouraging that the enhanced cell methane recovery has been close to 10-fold that experienced with conventional landfills. This is the highest methane recovery rate per unit waste, and thus progress toward stabilization, documented anywhere for such a large waste mass. This high recovery rate is attributed to moisture, and elevated temperature attained inexpensively during startup. Economic analyses performed under Phase I of this NETL contract indicate ''greenhouse cost effectiveness'' to be excellent. Other benefits include substantial waste volume loss (over 30%) which translates to extended landfill life. Other environmental benefits include rapidly improved quality and stabilization (lowered pollutant levels) in liquid leachate which drains from the waste.

Don Augenstein

2001-02-01T23:59:59.000Z

176

Maximum Entropy Analysis of the Spectral Functions in Lattice QCD  

E-Print Network [OSTI]

First principle calculation of the QCD spectral functions (SPFs) based on the lattice QCD simulations is reviewed. Special emphasis is placed on the Bayesian inference theory and the Maximum Entropy Method (MEM), which is a useful tool to extract SPFs from the imaginary-time correlation functions numerically obtained by the Monte Carlo method. Three important aspects of MEM are (i) it does not require a priori assumptions or parametrizations of SPFs, (ii) for given data, a unique solution is obtained if it exists, and (iii) the statistical significance of the solution can be quantitatively analyzed. The ability of MEM is explicitly demonstrated by using mock data as well as lattice QCD data. When applied to lattice data, MEM correctly reproduces the low-energy resonances and shows the existence of high-energy continuum in hadronic correlation functions. This opens up various possibilities for studying hadronic properties in QCD beyond the conventional way of analyzing the lattice data. Future problems to be studied by MEM in lattice QCD are also summarized.

M. Asakawa; T. Hatsuda; Y. Nakahara

2001-02-26T23:59:59.000Z

177

Improved Maximum Entropy Method with an Extended Search Space  

E-Print Network [OSTI]

We report on an improvement to the implementation of the Maximum Entropy Method (MEM). It amounts to departing from the search space obtained through a singular value decomposition (SVD) of the Kernel. Based on the shape of the SVD basis functions we argue that the MEM spectrum for given $N_\\tau$ data-points $D(\\tau)$ and prior information $m(\\omega)$ does not in general lie in this $N_\\tau$ dimensional singular subspace. Systematically extending the search basis will eventually recover the full search space and the correct extremum. We illustrate this idea through a mock data analysis inspired by actual lattice spectra, to show where our improvement becomes essential for the success of the MEM. To remedy the shortcomings of Bryan's SVD prescription we propose to use the real Fourier basis, which consists of trigonometric functions. Not only does our approach lead to more stable numerical behavior, as the SVD is not required for the determination of the basis functions, but also the resolution of the MEM becomes independent from the position of the reconstructed peaks.

Alexander Rothkopf

2012-08-25T23:59:59.000Z

178

Maximum entropy detection of planets around active stars  

E-Print Network [OSTI]

(shortened for arXiv) We aim to progress towards more efficient exoplanet detection around active stars by optimizing the use of Doppler Imaging in radial velocity measurements. We propose a simple method to simultaneously extract a brightness map and a set of orbital parameters through a tomographic inversion technique derived from classical Doppler mapping. Based on the maximum entropy principle, the underlying idea is to determine the set of orbital parameters that minimizes the information content of the resulting Doppler map. We carry out a set of numerical simulations to perform a preliminary assessment of the robustness of our method, using an actual Doppler map of the very active star HR 1099 to produce a realistic synthetic data set for various sets of orbital parameters of a single planet in a circular orbit. Using a simulated time-series of 50 line profiles affected by a peak-to-peak activity jitter of 2.5 km/s, we are able in most cases to recover the radial velocity amplitude, orbital phase and o...

Petit, P; Hbrard, E; Morin, J; Folsom, C P; Bhm, T; Boisse, I; Borgniet, S; Bouvier, J; Delfosse, X; Hussain, G; Jeffers, S V; Marsden, S C; Barnes, J R

2015-01-01T23:59:59.000Z

179

Design and implementation of a scalable encryption processor with embedded variable dc/dc converter  

E-Print Network [OSTI]

This work describes the design and implementation of an energy-efficient, scalable encryption processor that utilizes variable voltage supply techniques and a highefficiency embedded variable output DC/DC converter. The resulting implementation dissipates 134nJ/bit @ V DD = 2.5V, when encrypting at its maximum rate of 1Mb/s using a maximum datapath width of 512 bits. The embedded converter achieves an efficiency of 96 % at this peak load. The processor is 2-3 orders of magnitude more energy efficient than optimized assembly code running on a low-power processor such as the StrongARM. 2.

James Goodman; Anantha Chandrakasan; Abram P. Dancy

1999-01-01T23:59:59.000Z

180

From Physics to Economics: An Econometric Example Using Maximum Relative Entropy  

E-Print Network [OSTI]

Econophysics, is based on the premise that some ideas and methods from physics can be applied to economic situations. We intend to show in this paper how a physics concept such as entropy can be applied to an economic problem. In so doing, we demonstrate how information in the form of observable data and moment constraints are introduced into the method of Maximum relative Entropy (MrE). A general example of updating with data and moments is shown. Two specific econometric examples are solved in detail which can then be used as templates for real world problems. A numerical example is compared to a large deviation solution which illustrates some of the advantages of the MrE method.

Giffin, Adom

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Online Robot Dead Reckoning Localization Using Maximum Relative Entropy Optimization With Model Constraints  

SciTech Connect (OSTI)

The principle of Maximum relative Entropy optimization was analyzed for dead reckoning localization of a rigid body when observation data of two attached accelerometers was collected. Model constraints were derived from the relationships between the sensors. The experiment's results confirmed that accelerometers each axis' noise can be successfully filtered utilizing dependency between channels and the dependency between time series data. Dependency between channels was used for a priori calculation, and a posteriori distribution was derived utilizing dependency between time series data. There was revisited data of autocalibration experiment by removing the initial assumption that instantaneous rotation axis of a rigid body was known. Performance results confirmed that such an approach could be used for online dead reckoning localization.

Urniezius, Renaldas [Kaunas University of Technology, Kaunas (Lithuania)

2011-03-14T23:59:59.000Z

182

Spectral Analysis of Excited Nucleons in Lattice QCD with Maximum Entropy Method  

E-Print Network [OSTI]

We study the mass spectra of excited baryons with the use of the lattice QCD simulations. We focus our attention on the problem of the level ordering between the positive-parity excited state N'(1440) (the Roper resonance) and the negative-parity excited state N^*(1535). Nearly perfect parity projection is accomplished by combining the quark propagators with periodic and anti-periodic boundary conditions in the temporal direction. Then we extract the spectral functions from the lattice data by utilizing the maximum entropy method. We observe that the masses of the N' and N^* states are close for wide range of the quark masses (M_pi=0.61-1.22 GeV), which is in contrast to the phenomenological prediction of the quark models. The role of the Wilson doublers in the baryonic spectral functions is also studied.

Kiyoshi Sasaki; Shoichi Sasaki; Tetsuo Hatsuda

2005-07-12T23:59:59.000Z

183

Application of the Maximum Entropy Method to the (2+1)d Four-Fermion Model  

E-Print Network [OSTI]

We investigate spectral functions extracted using the Maximum Entropy Method from correlators measured in lattice simulations of the (2+1)-dimensional four-fermion model. This model is particularly interesting because it has both a chirally broken phase with a rich spectrum of mesonic bound states and a symmetric phase where there are only resonances. In the broken phase we study the elementary fermion, pion, sigma and massive pseudoscalar meson; our results confirm the Goldstone nature of the pi and permit an estimate of the meson binding energy. We have, however, seen no signal of sigma -> pi pi decay as the chiral limit is approached. In the symmetric phase we observe a resonance of non-zero width in qualitative agreement with analytic expectations; in addition the ultra-violet behaviour of the spectral functions is consistent with the large non-perturbative anomalous dimension for fermion composite operators expected in this model.

C. R. Allton; J. E. Clowser; S. J. Hands; J. B. Kogut; C. G. Strouthos

2002-08-19T23:59:59.000Z

184

Correlated spectral variability in brown dwarfs  

E-Print Network [OSTI]

Models of brown dwarf atmospheres suggest they exhibit complex physical behaviour. Observations have shown that they are indeed dynamic, displaying small photometric variations over timescales of hours. Here I report results of infrared (0.95-1.64 micron) spectrophotometric monitoring of four field L and T dwarfs spanning timescales of 0.1-5.5 hrs, the goal being to learn more about the physical nature of this variability. Spectra are analysed differentially with respect to a simultaneously observed reference source in order to remove Earth-atmospheric variations. The variability amplitude detected is typically 2-10%, depending on the source and wavelength. I analyse the data for correlated variations between spectral indices. This approach is more robust than single band or chisq analyses, because it does not assume an amplitude for the (often uncertain) noise level (although the significance test still assumes a shape for the noise power spectrum). Three of the four targets show significant evidence for correlated variability. Some of this can be associated with specific features including Fe, FeH, VO and KI, and there is good evidence for intrinsic variability in water and possibly also methan. Yet some of this variability covers a broader spectral range which would be consistent with dust opacity variations. The underlying common cause is plausibly localized temperature or composition fluctuations caused by convection. Looking at the high signal-to-noise ratio stacked spectra we see many previously identified spectral features of L and T dwarfs, such as KI, NaI, FeH, water and methane. In particular we may have detected methane absorption at 1.3-1.4 micron in the L5 dwarf SDSS 0539-0059.

C. A. L. Bailer-Jones

2007-11-28T23:59:59.000Z

185

Copulas with Maximum Entropy Julia Piantadosi, Phil Howlett, Jonathan Borwein  

E-Print Network [OSTI]

reflect observed rainfall patterns. In a recent model of a storm- water management system at Parafield storm-water systems can be demonstrated effectively using com- puter graphics simulation packages calculations for some hypothetical examples and describe how this work can be applied to the modelling

Borwein, Jonathan

186

Universalities in hadron production and the maximum entropy principle  

E-Print Network [OSTI]

A shape of statistical momentum distribution of hadrons produced in high energy particle collisions closely resembles one observed for a broad variety of phenomena in nature. An attempt was made to understand a genesis of this distribution beyond the context of each particular phenomenon.

A. Kropivnitskaya; A. Rostovtsev

2005-01-04T23:59:59.000Z

187

Study of Different Implementation Approaches for a Maximum Power Point Florent Boico Brad Lehman  

E-Print Network [OSTI]

will study the design of a maximum power point tracker for low power solar panels (10-50W). In the process weStudy of Different Implementation Approaches for a Maximum Power Point Tracker 1 Florent Boico Brad Lehman Northeastern University Abstract: This paper studies the design of a Maximum Power Point Tracker

Lehman, Brad

188

A Maximum Entropy Algorithm for Rhythmic Analysis of Genome-Wide Expression Patterns  

E-Print Network [OSTI]

A Maximum Entropy Algorithm for Rhythmic Analysis of Genome-Wide Expression Patterns Christopher James Langmead C. Robertson McClung Bruce Randall Donald ,,,§,¶ Abstract We introduce a maximum entropy-based spectral analysis, maximum entropy spectral reconstruction is well suited to signals of the type generated

Richardson, David

189

1 A MAXIMUM ENTROPY METHOD FOR SUBNETWORK ORIGIN-DESTINATION 2 TRIP MATRIX ESTIMATION  

E-Print Network [OSTI]

1 A MAXIMUM ENTROPY METHOD FOR SUBNETWORK ORIGIN-DESTINATION 2 TRIP MATRIX ESTIMATION 3 4 Chi Xie 5, maximum entropy, linearization 36 algorithm, column generation 37 #12;C. Xie, K.M. Kockelman and S is the trip matrix of the simplified network. This paper discusses a5 maximum entropy method

Kockelman, Kara M.

190

Maximum entropy and Bayesian approaches to the ratio problem Edward Z. Shen*  

E-Print Network [OSTI]

Maximum entropy and Bayesian approaches to the ratio problem Edward Z. Shen* Jeffrey M. Perloff** January 2001 Abstract Maximum entropy and Bayesian approaches provide superior estimates of a ratio extra information in the supports for the underlying parameters for generalized maximum entropy (GME

Perloff, Jeffrey M.

191

Comparison of Maximum Entropy and Higher-Order Entropy Estimators Amos Golan* and Jeffrey M. Perloff**  

E-Print Network [OSTI]

Comparison of Maximum Entropy and Higher-Order Entropy Estimators Amos Golan* and Jeffrey M. Perloff** ABSTRACT We show that the generalized maximum entropy (GME) is the only estimation method- classes of estimators may outperform the GME estimation rule. Keywords: generalized entropy, maximum

Perloff, Jeffrey M.

192

A maximum entropy-least squares estimator for elastic origin-destination trip matrix estimation  

E-Print Network [OSTI]

A maximum entropy-least squares estimator for elastic origin- destination trip matrix estimation propose a combined maximum entropy-least squares (ME-LS) estimator, by which O- D flows are distributed-destination trip table; elastic demand; maximum entropy; least squares; subnetwork analysis; convex combination

Kockelman, Kara M.

193

THE MAXIMUM ENERGY OF ACCELERATED PARTICLES IN RELATIVISTIC COLLISIONLESS SHOCKS  

SciTech Connect (OSTI)

The afterglow emission from gamma-ray bursts (GRBs) is usually interpreted as synchrotron radiation from electrons accelerated at the GRB external shock that propagates with relativistic velocities into the magnetized interstellar medium. By means of multi-dimensional particle-in-cell simulations, we investigate the acceleration performance of weakly magnetized relativistic shocks, in the magnetization range 0 {approx}< {sigma} {approx}< 10{sup -1}. The pre-shock magnetic field is orthogonal to the flow, as generically expected for relativistic shocks. We find that relativistic perpendicular shocks propagating in electron-positron plasmas are efficient particle accelerators if the magnetization is {sigma} {approx}< 10{sup -3}. For electron-ion plasmas, the transition to efficient acceleration occurs for {sigma} {approx}< 3 Multiplication-Sign 10{sup -5}. Here, the acceleration process proceeds similarly for the two species, since the electrons enter the shock nearly in equipartition with the ions, as a result of strong pre-heating in the self-generated upstream turbulence. In both electron-positron and electron-ion shocks, we find that the maximum energy of the accelerated particles scales in time as {epsilon}{sub max}{proportional_to}t {sup 1/2}. This scaling is shallower than the so-called (and commonly assumed) Bohm limit {epsilon}{sub max}{proportional_to}t, and it naturally results from the small-scale nature of the Weibel turbulence generated in the shock layer. In magnetized plasmas, the energy of the accelerated particles increases until it reaches a saturation value {epsilon}{sub sat}/{gamma}{sub 0} m{sub i}c {sup 2} {approx} {sigma}{sup -1/4}, where {gamma}{sub 0} m{sub i}c {sup 2} is the mean energy per particle in the upstream bulk flow. Further energization is prevented by the fact that the self-generated turbulence is confined within a finite region of thickness {proportional_to}{sigma}{sup -1/2} around the shock. Our results can provide physically grounded inputs for models of non-thermal emission from a variety of astrophysical sources, with particular relevance to GRB afterglows.

Sironi, Lorenzo [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Spitkovsky, Anatoly [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544-1001 (United States); Arons, Jonathan, E-mail: lsironi@cfa.harvard.edu [Department of Astronomy, Department of Physics, and Theoretical Astrophysics Center, University of California, Berkeley, CA 94720 (United States)

2013-07-01T23:59:59.000Z

194

LANDFILL OPERATION FOR CARBON SEQUESTRATION AND MAXIMUM METHANE EMISSION CONTROL  

SciTech Connect (OSTI)

Controlled landfilling is an approach to manage solid waste landfills, so as to rapidly complete methane generation, while maximizing gas capture and minimizing the usual emissions of methane to the atmosphere. With controlled landfilling, methane generation is accelerated to more rapid and earlier completion to full potential by improving conditions (principally moisture, but also temperature) to optimize biological processes occurring within the landfill. Gas is contained through use of surface membrane cover. Gas is captured via porous layers, under the cover, operated at slight vacuum. A field demonstration project has been ongoing under NETL sponsorship for the past several years near Davis, CA. Results have been extremely encouraging. Two major benefits of the technology are reduction of landfill methane emissions to minuscule levels, and the recovery of greater amounts of landfill methane energy in much shorter times, more predictably, than with conventional landfill practice. With the large amount of US landfill methane generated, and greenhouse potency of methane, better landfill methane control can play a substantial role both in reduction of US greenhouse gas emissions and in US renewable energy. The work described in this report, to demonstrate and advance this technology, has used two demonstration-scale cells of size (8000 metric tons [tonnes]), sufficient to replicate many heat and compaction characteristics of larger ''full-scale'' landfills. An enhanced demonstration cell has received moisture supplementation to field capacity. This is the maximum moisture waste can hold while still limiting liquid drainage rate to minimal and safely manageable levels. The enhanced landfill module was compared to a parallel control landfill module receiving no moisture additions. Gas recovery has continued for a period of over 4 years. It is quite encouraging that the enhanced cell methane recovery has been close to 10-fold that experienced with conventional landfills. This is the highest methane recovery rate per unit waste, and thus progress toward stabilization, documented anywhere for such a large waste mass. This high recovery rate is attributed to moisture, and elevated temperature attained inexpensively during startup. Economic analyses performed under Phase I of this NETL contract indicate ''greenhouse cost effectiveness'' to be excellent. Other benefits include substantial waste volume loss (over 30%) which translates to extended landfill life. Other environmental benefits include rapidly improved quality and stabilization (lowered pollutant levels) in liquid leachate which drains from the waste.

Don Augenstein; Ramin Yazdani; Rick Moore; Michelle Byars; Jeff Kieffer; Professor Morton Barlaz; Rinav Mehta

2000-02-26T23:59:59.000Z

195

A powerful and highly variable off-nuclear X-ray source in the composite starburst/Seyfert 2 galaxy NGC 4945  

E-Print Network [OSTI]

We report on a powerful and variable off-nuclear X-ray source in the nearby spiral galaxy NGC 4945. Two ROSAT PSPC observations show the source to brighten in 0.5--2.0 keV flux by a factor of about 9 on a time-scale of 11 months or less. It is seen by ASCA about one month after the second PSPC pointing, and is seen to have dimmed by a factor of > 7 in a ROSAT HRI pointing about one year after the second PSPC pointing. Its maximum observed 0.8--2.5 keV luminosity is about 8E38 erg/s, making it brighter than any known persistent X-ray binary in the Milky Way. Its total X-ray luminosity is probably larger than 1.2E39 erg/s. The observed variability argues against a superbubble interpretation, and the off-nuclear position argues against a low-luminosity active galactic nucleus. The source is therefore probably either an ultra-powerful X-ray binary or an ultra-powerful supernova remnant. Optical monitoring has not identified any supernovae in NGC 4945 during the time of the X-ray observations, and any supernova would have had to have been either very highly absorbed or intrinsically optically faint.

W. N. Brandt; K. Iwasawa; C. S. Reynolds

1996-07-02T23:59:59.000Z

196

Identification of the feature that causes the I-band secondary maximum of a type Ia supernova  

E-Print Network [OSTI]

We obtained a time series of spectra covering the secondary maximum in the I-band of the bright Type Ia supernova 2014J in M82 with the TIGRE telescope. Comparing the observations with theoretical models calculated with the time dependent extension of the PHOENIX code, we identify the feature that causes the secondary maximum in the I-band light curve. Fe II 3d6(3D)4s-3d6(5D)4p and similar high excitation transitions produce a blended feature at 7500 {\\AA}, which causes the rise of the light curve towards the secondary maximum. The series of observed spectra of SN 2014J and archival data of SN 2011fe confirm this conclusion. We further studied the plateau phase of the Rband light curve of SN 2014J and searched for features which contribute to the flux. The theoretical models do not clearly indicate a new feature that may cause the Rband plateau phase. However, Co II features in the range of 6500 - 7000 {\\AA} and the Fe II feature of the I-band are clearly seen in the theoretical spectra, but do not appear to ...

Jack, D; Hauschildt, P H

2015-01-01T23:59:59.000Z

197

Rotating Winds from Accretion Disks in Cataclysmic Variables: Eclipse Modeling of V347 Puppis  

E-Print Network [OSTI]

We study the eclipsing nova-like variable V347 Pup by matching its UV emission line profiles in and out of eclipse to synthetic lines using a 3D kinematic and radiation transfer model. Our results support the accretion disk origin of winds in non-magnetic CVs as opposite to the WD origin. Our main point concerns the importance of rotation for the UV emission line shapes in such systems. In particular, we show that the narrowing of the UV emission lines in V347 Pup during eclipse can be easily explained by the eclipse of the innermost part of the wind by the secondary and the resulting reduction in the contribution of rotational broadening to the width of the lines. During the eclipse, the residual line flux is very sensitive to the maximal temperature of disk radiation. Good fits for reasonable mass-loss rates have been obtained for maximum disk temperatures of 50,000 degrees. This constraint was imposed either by leveling off the inner disk temperature profiles, in agreement with recent observations of some nova-like objects, or by assuming that the accretion disk does not extend to the surface of the white dwarf, in which case V347 up would be an intermediate polar. In anticipation of high-speed spectrophotometry of CVs by the HST, we provide numerical model of a time-resolved eclipse of V347 Pup or similar such system to be verified by future observations.

Isaac Shlosman; Peter Vitello; Christopher W. Mauche

1995-11-01T23:59:59.000Z

198

Selection automatique de variables pertinentes  

E-Print Network [OSTI]

S´election automatique de variables pertinentes Vers la d´ecouverte de nouvelles modalit´es sensori-motrices corr´elations entre ses variables sensori-motrices afin d'apprendre `a r´esoudre sa t^ache d

Boyer, Edmond

199

Pitch-controlled variable-speed wind turbine generation  

SciTech Connect (OSTI)

Wind energy is a viable option to complement other types of pollution-free generation. In the early development of wind energy, the majority of wind turbines were operated at constant speed. Recently, the number of variable-speed wind turbines installed in wind farms has increased and more wind turbine manufacturers are making variable-speed wind turbines. This paper covers the operation of variable-speed wind turbines with pitch control. The system the authors considered is controlled to generate maximum energy while minimizing loads. The maximization of energy was only carried out on a static basis and only drive train loads were considered as a constraint. In medium wind speeds, the generator and power converter control the wind turbine to capture maximum energy from the wind. In the high wind speed region, the wind turbine is controlled to maintain the aerodynamic power produced by the wind turbine. Two methods to adjust the aerodynamic power were investigated: pitch control and generator load control, both of which are employed to control the operation of the wind turbine. The analysis and simulation shows that the wind turbine can be operated at its optimum energy capture while minimizing the load on the wind turbine for a wide range of wind speeds.

Muljadi, E.; Butterfield, C.P.

2000-03-01T23:59:59.000Z

200

A maximum entropy framework for non-exponential distributions  

E-Print Network [OSTI]

Probability distributions having power-law tails are observed in a broad range of social, economic, and biological systems. We describe here a potentially useful common framework. We derive distribution functions $\\{p_k\\}$ for situations in which a `joiner particle' $k$ pays some form of price to enter a `community' of size $k-1$, where costs are subject to economies-of-scale (EOS). Maximizing the Boltzmann-Gibbs-Shannon entropy subject to this energy-like constraint predicts a distribution having a power-law tail; it reduces to the Boltzmann distribution in the absence of EOS. We show that the predicted function gives excellent fits to 13 different distribution functions, ranging from friendship links in social networks, to protein-protein interactions, to the severity of terrorist attacks. This approach may give useful insights into when to expect power-law distributions in the natural and social sciences.

Peterson, Jack; Dill, Ken A

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Time resolved spectroscopy of the variable brown dwarf Kelu-1  

E-Print Network [OSTI]

We report the results of observations designed to investigate the spectroscopic signatures of dust clouds on the L2 brown dwarf Kelu-1. Time resolved medium resolution spectra show no significant evidence of variability in the dust sensitive TiO, CrH and FeH bandheads on the timescale of 1--24 hours. We do however report periodic variability in the psuedo-equivelent width of H-alpha consistent with the 1.8 hour rotation period previously reported for this object Clarke, Tinney & Tolley (2002). Near-contemporaneous I-band photometry shows evidence for non-periodic variability at the level of 2%.

F. J. Clarke; C. G. Tinney; S. T. Hodgkin

2003-01-09T23:59:59.000Z

202

D i i f S t i bilit i th B ilt E i tDesigning for Sustainability in the Built Environment Exterior Facade Design for Maximum Daylighting and Solar Power  

E-Print Network [OSTI]

Facade Design for Maximum Daylighting and Solar Power GenerationGeneration A frank assessment of issues "...the art and science of daylighting is not so much about how to provide enough daylighting as how to do LIGHTING CHARACTER DUE TO DAYLIGHT VARIABILITY · PSYCHOLOGICAL BENEFITS OF· PSYCHOLOGICAL BENEFITS

Massachusetts at Amherst, University of

203

Variability of the Caribbean Low-Level Jet and its relations Chunzai Wang  

E-Print Network [OSTI]

Variability of the Caribbean Low-Level Jet and its relations to climate Chunzai Wang Received: 11 Abstract A maximum of easterly zonal wind at 925 hPa in the Caribbean region is called the Caribbean Low), and a minimum of tropical cyclo- genesis in July in the Caribbean Sea. It is found that both the meridional

Wang, Chunzai

204

Quantum information with modular variables  

E-Print Network [OSTI]

We introduce a novel strategy, based on the use of modular variables, to encode and deterministically process quantum information using states described by continuous variables. Our formalism leads to a general recipe to adapt existing quantum information protocols, originally formulated for finite dimensional quantum systems, to infinite dimensional systems described by continuous variables. This is achieved by using non unitary and non-gaussian operators, obtained from the superposition of gaussian gates, together with adaptative manipulations in qubit systems defined in infinite dimensional Hilbert spaces. We describe in details the realization of single and two qubit gates and briefly discuss their implementation in a quantum optical set-up.

A. Ketterer; S. P. Walborn; A. Keller; T. Coudreau; P. Milman

2014-06-24T23:59:59.000Z

205

Ocean Observing Ocean Observing Systems (OOS)  

E-Print Network [OSTI]

, national, and global scales. · Ocean Observing Systems serve: Fishing industry National security Coastal properties, such as salinity, temperature, and waves Satellite maps of sea surface temperature NATIONAL Integrated Ocean Observing System (IOOS) 11 REGIONAL Systems, including: MANY LOCAL Systems

Schladow, S. Geoffrey

206

MID-INFRARED SPECTRAL VARIABILITY ATLAS OF YOUNG STELLAR OBJECTS  

SciTech Connect (OSTI)

Optical and near-infrared variability is a well-known property of young stellar objects. However, a growing number of recent studies claim that a considerable fraction of them also exhibit mid-infrared flux changes. With the aim of studying and interpreting variability on a decadal timescale, here we present a mid-infrared spectral atlas containing observations of 68 low- and intermediate-mass young stellar objects. The atlas consists of 2.5-11.6 {mu}m low-resolution spectra obtained with the ISOPHOT-S instrument on board the Infrared Space Observatory (ISO) between 1996 and 1998, as well as 5.2-14.5 {mu}m low-resolution spectra obtained with the Infrared Spectrograph instrument on board the Spitzer Space Telescope between 2004 and 2007. The observations were retrieved from the ISO and Spitzer archives and were post-processed interactively by our own routines. For those 47 objects where multi-epoch spectra were available, we analyze mid-infrared spectral variability on annual and/or decadal timescales. We identify 37 variable candidate sources. Many stars show wavelength-independent flux changes, possibly due to variable accretion rates. In several systems, all exhibiting 10 {mu}m silicate emission, the variability of the 6-8 {mu}m continuum, and the silicate feature exhibit different amplitudes. A possible explanation is variable shadowing of the silicate-emitting region by an inner disk structure of changing height or extra silicate emission from dust clouds in the disk atmosphere. Our results suggest that mid-infrared variability, in particular, the wavelength-dependent changes, is more ubiquitous than was known before. Interpreting this variability is a new possibility for exploring the structure of the disk and its dynamical processes.

Kospal, A. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA, Leiden (Netherlands); Abraham, P.; Kun, M.; Moor, A. [Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, P.O. Box 67, 1525 Budapest (Hungary); Acosta-Pulido, J. A. [Instituto de Astrofisica de Canarias, Via Lactea s/n, 38200 La Laguna, Tenerife (Spain); Dullemond, C. P. [Institut fuer Theoretische Astrophysik, Zentrum fuer Astronomie der Universitaet Heidelberg, Albert-Ueberle-Str. 2, 69120 Heidelberg (Germany); Henning, Th.; Leinert, Ch. [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, 69117 Heidelberg (Germany); Turner, N. J., E-mail: akospal@rssd.esa.int [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

2012-08-01T23:59:59.000Z

207

VARIABILITY OF KD VALUES IN CEMENTITIOUS MATERIALS AND SEDIMENTS  

SciTech Connect (OSTI)

Measured distribution coefficients (K{sub d} values) for environmental contaminants provide input data for performance assessments (PA) that evaluate physical and chemical phenomena for release of radionuclides from wasteforms, degradation of engineered components and subsequent transport of radionuclides through environmental media. Research efforts at SRNL to study the effects of formulation and curing variability on the physiochemical properties of the saltstone wasteform produced at the Saltstone Disposal Facility (SDF) are ongoing and provide information for the PA and Saltstone Operations. Furthermore, the range and distribution of plutonium K{sub d} values in soils is not known. Knowledge of these parameters is needed to provide guidance for stochastic modeling in the PA. Under the current SRS liquid waste processing system, supernate from F & H Tank Farm tanks is processed to remove actinides and fission products, resulting in a low-curie Decontaminated Salt Solution (DSS). At the Saltstone Production Facility (SPF), DSS is mixed with premix, comprised of blast furnace slag (BFS), Class F fly ash (FA), and portland cement (OPC) to form a grout mixture. The fresh grout is subsequently placed in SDF vaults where it cures through hydration reactions to produce saltstone, a hardened monolithic waste form. Variation in saltstone composition and cure conditions of grout can affect the saltstone's physiochemical properties. Variations in properties may originate from variables in DSS, premix, and water to premix ratio, grout mixing, placing, and curing conditions including time and temperature (Harbour et al. 2007; Harbour et al. 2009). There are no previous studies reported in the literature regarding the range and distribution of K{sub d} values in cementitious materials. Presently, the Savannah River Site (SRS) estimate ranges and distributions of K{sub d} values based on measurements of K{sub d} values made in sandy SRS sediments (Kaplan 2010). The actual cementitious material K{sub d} values and solubility values differ from the sandy sediments. The K{sub d} value range and distribution currently used in the PA are estimated to range between 0.25*K{sub d} and 1.75*K{sub d}, where the minimum and maximum values of the ranges reflect the 95% confidence level for the mean K{sub d} value (Kaplan 2010). The objective of the research with cementitious materials was to measure the range and distribution of a monovalent (Cs) and I{sup -} (anion), divalent (Sr), and trivalent (Eu) ions for a variety of laboratory-prepared saltstone surrogate samples to establish a K{sub d} range other than that which is presently used in the PA. It has been observed in laboratory samples that cure temperature profiles can affect properties such as heat of hydration, permeability, porosity, compressive strength, and set time (Harbour et al. 2009). The intent was to identify a range and distribution that could be used by stochastic modelers for the PA. Furthermore, the intent was to replace the arbitrarily selected distributions based on geological sandy sediments and to base it on actual cementitious materials. The scope of this study did not include understanding saltstone sorption mechanisms responsible for increasing or decreasing sorption. Similar to the work with cementitious materials, the purpose of the Pu sediment K{sub d} dataset was not to attempt to understand through statistics how to better understand Pu sorption to sediments or to lower Pu K{sub d} variance. The sediment Pu K{sub d} data is included in this study because it is a key risk driver for the PAs on the SRS, and there is presently no direct studies of Pu variability in SRS soils. Instead the distribution of Pu sediment K{sub d} values was assumed to be similar to other cations, as presented by Kaplan (2010).

Almond, P.; Kaplan, D.; Shine, E.

2012-02-02T23:59:59.000Z

208

Variable metric conjugate gradient methods  

SciTech Connect (OSTI)

1.1 Motivation. In this paper we present a framework that includes many well known iterative methods for the solution of nonsymmetric linear systems of equations, Ax = b. Section 2 begins with a brief review of the conjugate gradient method. Next, we describe a broader class of methods, known as projection methods, to which the conjugate gradient (CG) method and most conjugate gradient-like methods belong. The concept of a method having either a fixed or a variable metric is introduced. Methods that have a metric are referred to as either fixed or variable metric methods. Some relationships between projection methods and fixed (variable) metric methods are discussed. The main emphasis of the remainder of this paper is on variable metric methods. In Section 3 we show how the biconjugate gradient (BCG), and the quasi-minimal residual (QMR) methods fit into this framework as variable metric methods. By modifying the underlying Lanczos biorthogonalization process used in the implementation of BCG and QMR, we obtain other variable metric methods. These, we refer to as generalizations of BCG and QMR.

Barth, T.; Manteuffel, T.

1994-07-01T23:59:59.000Z

209

Occurrence of high-speed solar wind streams over the Grand Modern Maximum  

E-Print Network [OSTI]

In the declining phase of the solar cycle, when the new-polarity fields of the solar poles are strengthened by the transport of same-signed magnetic flux from lower latitudes, the polar coronal holes expand and form non-axisymmetric extensions toward the solar equator. These extensions enhance the occurrence of high-speed solar wind streams (HSS) and related co-rotating interaction regions in the low-latitude heliosphere, and cause moderate, recurrent geomagnetic activity in the near-Earth space. Here, using a novel definition of geomagnetic activity at high (polar cap) latitudes and the longest record of magnetic observations at a polar cap station, we calculate the annually averaged solar wind speeds as proxies for the effective annual occurrence of HSS over the whole Grand Modern Maximum (GMM) from 1920s onwards. We find that a period of high annual speeds (frequent occurrence of HSS) occurs in the declining phase of each solar cycle 16-23. For most cycles the HSS activity clearly maximizes during one year...

Mursula, Kalevi; Holappa, Lauri

2015-01-01T23:59:59.000Z

210

Maximum-entropy calculation of end-to-end distance distribution of force stretching chains  

E-Print Network [OSTI]

Using the maximum-entropy method, we calculate the end-to-end distance distribution of the force stretched chain from the moments of the distribution, which can be obtained from the extension-force curves recorded in single-molecule experiments. If one knows force expansion of the extension through the $(n-1)$th power of force, it is enough information to calculate the $n$ moments of the distribution. We examine the method with three force stretching chain models, Gaussian chain, free-joined chain and excluded-volume chain on two-dimension lattice. The method reconstructs all distributions precisely. We also apply the method to force stretching complex chain molecules: the hairpin and secondary structure conformations. We find that the distributions of homogeneous chains of two conformations are very different: there are two independent peaks in hairpin distribution; while only one peak is observed in the distribution of secondary structure conformations. Our discussion also shows that the end-to-end distance distribution may discover more critical physical information than the simpler extension-force curves can give.

Luru Dai; Fei Liu; Zhong-can Ou-Yang

2002-12-12T23:59:59.000Z

211

IS ACTIVE REGION CORE VARIABILITY AGE DEPENDENT?  

SciTech Connect (OSTI)

The presence of both steady and transient loops in active region cores has been reported from soft X-ray and extreme-ultraviolet observations of the solar corona. The relationship between the different loop populations, however, remains an open question. We present an investigation of the short-term variability of loops in the core of two active regions in the context of their long-term evolution. We take advantage of the nearly full Sun observations of STEREO and Solar Dynamics Observatory spacecraft to track these active regions as they rotate around the Sun multiple times. We then diagnose the variability of the active region cores at several instances of their lifetime using EIS/Hinode spectral capabilities. We inspect a broad range of temperatures, including for the first time spatially and temporally resolved images of Ca XIV and Ca XV lines. We find that the active region cores become fainter and steadier with time. The significant emission measure at high temperatures that is not correlated with a comparable increase at low temperatures suggests that high-frequency heating is viable. The presence, however, during the early stages, of an enhanced emission measure in the ''hot'' (3.0-4.5 MK) and ''cool'' (0.6-0.9 MK) components suggests that low-frequency heating also plays a significant role. Our results explain why there have been recent studies supporting both heating scenarios.

Ugarte-Urra, Ignacio [College of Science, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); Warren, Harry P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)

2012-12-10T23:59:59.000Z

212

BROAD ABSORPTION LINE VARIABILITY ON MULTI-YEAR TIMESCALES IN A LARGE QUASAR SAMPLE  

SciTech Connect (OSTI)

We present a detailed investigation of the variability of 428 C IV and 235 Si IV broad absorption line (BAL) troughs identified in multi-epoch observations of 291 quasars by the Sloan Digital Sky Survey-I/II/III. These observations primarily sample rest-frame timescales of 1-3.7 yr over which significant rearrangement of the BAL wind is expected. We derive a number of observational results on, e.g., the frequency of BAL variability, the velocity range over which BAL variability occurs, the primary observed form of BAL-trough variability, the dependence of BAL variability upon timescale, the frequency of BAL strengthening versus weakening, correlations between BAL variability and BAL-trough profiles, relations between C IV and Si IV BAL variability, coordinated multi-trough variability, and BAL variations as a function of quasar properties. We assess implications of these observational results for quasar winds. Our results support models where most BAL absorption is formed within an order-of-magnitude of the wind-launching radius, although a significant minority of BAL troughs may arise on larger scales. We estimate an average lifetime for a BAL trough along our line-of-sight of a few thousand years. BAL disappearance and emergence events appear to be extremes of general BAL variability, rather than being qualitatively distinct phenomena. We derive the parameters of a random-walk model for BAL EW variability, finding that this model can acceptably describe some key aspects of EW variability. The coordinated trough variability of BAL quasars with multiple troughs suggests that changes in 'shielding gas' may play a significant role in driving general BAL variability.

Filiz Ak, N.; Brandt, W. N.; Schneider, D. P. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Hall, P. B. [Department of Physics and Astronomy, York University, 4700 Keele St., Toronto, Ontario, M3J 1P3 (Canada); Anderson, S. F. [Astronomy Department, University of Washington, Seattle, WA 98195 (United States); Hamann, F. [Department of Astronomy, University of Florida, Gainesville, FL 32611-2055 (United States); Lundgren, B. F. [Department of Astronomy, University of Wisconsin, Madison, WI 53706 (United States); Myers, Adam D. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Pris, I. [Departamento de Astronoma, Universidad de Chile, Casilla 36-D, Santiago (Chile); Petitjean, P. [Universite Paris 6, Institut d'Astrophysique de Paris, 75014, Paris (France); Ross, Nicholas P. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 92420 (United States); Shen, Yue [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., MS-51, Cambridge, MA 02138 (United States); York, Don, E-mail: nfilizak@astro.psu.edu [The University of Chicago, Department of Astronomy and Astrophysics, Chicago, IL 60637 (United States)

2013-11-10T23:59:59.000Z

213

A PHOTOMETRICALLY AND MORPHOLOGICALLY VARIABLE INFRARED NEBULA IN L483  

SciTech Connect (OSTI)

We present narrow and broad K-band observations of the Class 0/I source IRAS 18148-0440 that span 17 years. The infrared nebula associated with this protostar in the L483 dark cloud is both morphologically and photometrically variable on a timescale of only a few months. This nebula appears to be an infrared analog to other well known optically visible variable nebulae associated with young stars, such as Hubble's Variable Nebula. Along with Cepheus A, this is one of the first large variable nebulae to be found that is only visible in the infrared. The variability of this nebula is most likely due to changing illumination of the cloud rather than any motion of the structure in the nebula. Both morphological and photometric changes are observed on a timescale only a few times longer than the light crossing time of the nebula, suggesting very rapid intrinsic changes in the illumination of the nebula. Our narrowband observations also found that H{sub 2} knots are found nearly twice as far to the east of the source as to its west, and that H{sub 2} emission extends farther east of the source than the previously known CO outflow.

Connelley, Michael S. [NASA Ames Research Center, MS 245-6, Moffett Field, CA 94035 (United States); Hodapp, Klaus W. [University of Hawaii Institute for Astronomy, 640 N. Aohoku Pl., Hilo, HI 96720 (United States); Fuller, Gary A. [Jodrell Bank Centre for Astrophysics, Alan Turing Building, University of Manchester, Manchester, M13 9PL (United Kingdom)

2009-03-15T23:59:59.000Z

214

LANGMUIR WAVE ACTIVITY: COMPARING THE ULYSSES SOLAR MINIMUM AND SOLAR MAXIMUM ORBITS  

E-Print Network [OSTI]

). The top three panels correspond to the southern segment of the solar minimum orbit; repeated passesLANGMUIR WAVE ACTIVITY: COMPARING THE ULYSSES SOLAR MINIMUM AND SOLAR MAXIMUM ORBITS R. J at the electron plasma frequency) during the solar minimum and solar maximum orbits of Ulysses. At high latitudes

California at Berkeley, University of

215

On the duration of the Paleocene-Eocene thermal maximum Ursula Rohl and Thomas Westerhold  

E-Print Network [OSTI]

On the duration of the Paleocene-Eocene thermal maximum (PETM) Ursula Ro¨hl and Thomas Westerhold of California, Santa Cruz, California 95064, USA [1] The Paleocene-Eocene thermal maximum (PETM) is one of global warming and a massive perturbation of the global carbon cycle from injection of isotopically light

Zachos, James

216

An Optimal Randomized Algorithm for Maximum Tukey Depth Timothy M. Chan  

E-Print Network [OSTI]

An Optimal Randomized Algorithm for Maximum Tukey Depth Timothy M. Chan Abstract We present the first optimal algorithm to compute the maximum Tukey depth (also known as location or halfspace depth , the Tukey depth of a point q IRd is defined as: min{|P | : over all halfspaces containing q}. We

Chan, Timothy M.

217

Beating the maximum cooling limit with graded thermoelectric materials Zhixi Bian and Ali Shakouria  

E-Print Network [OSTI]

.1063/1.2396895 The maximum cooling temperature is one of the perfor- mance parameters for a thermoelectric module. ExcludingBeating the maximum cooling limit with graded thermoelectric materials Zhixi Bian and Ali Shakouria cooling of a single element thermoelectric material cannot be improved by changing its geometry.3

218

Maximum Power Transfer Tracking in a Solar USB Charger for Smartphones  

E-Print Network [OSTI]

chargers do not perform the maximum power point tracking [2], [3] of the solar panel. We excludeMaximum Power Transfer Tracking in a Solar USB Charger for Smartphones Abstract--Battery life poor capacity utilization during solar energy harvesting. In this paper, we propose and demonstrate

Pedram, Massoud

219

Maximum-Power-Point Tracking Method of Photovoltaic Using Only Single Current Sensor  

E-Print Network [OSTI]

Solar cell systems Abstract This paper describes a novel strategy of maximum-power-point tracking point using only a single current sensor, i.e., a Hall-effect CT. Output power of the photovoltaic can-climbing method is employed to seek the maximum power point, using the output power obtained from only the current

Fujimoto, Hiroshi

220

A Basic Thermodynamic Derivation of the Maximum Overburden Pressure Generated in Frost Heave  

E-Print Network [OSTI]

can derive the maximum overburden pressure. A similar argument can also produce the maximum Heave Engine Frost heave is a common environmental process in which the freezing of water into ice can produce forces large enough to seriously damage roads and bridges [1]. Contrary to common belief, frost

Libbrecht, Kenneth G.

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Frequency Moments Inverse Problem and Maximum (Shannon vs. R enyi-Tsallis) Entropy  

E-Print Network [OSTI]

) maximization of Shannon's entropy (MaxEnt), b) maximization of R#19;enyi-Tsallis entropy (maxTent). ConcerningEnt 4 1.2 Aims 5 2 Frequency moment constraints 5 2.1 Characteristics of MaxEnt choice 6 2.2 Maximum RFrequency Moments Inverse Problem and Maximum (Shannon vs. R#19;enyi-Tsallis) Entropy #3; A case

222

How Is the Maximum Entropy of a Quantized Surface Related to Its Area?  

E-Print Network [OSTI]

The maximum entropy of a quantized surface is demonstrated to be proportional to the surface area in the classical limit. The result is valid in loop quantum gravity, and in a somewhat more general class of approaches to surface quantization. The maximum entropy is calculated explicitly for some specific cases.

I. B. Khriplovich; R. V. Korkin

2001-12-27T23:59:59.000Z

223

Maximum Theoretical Efficiency Limit of Photovoltaic Devices: Effect of Band Structure on Excited State Entropy  

E-Print Network [OSTI]

, we show that the maximum conversion efficiency is limited further by the excited state entropyMaximum Theoretical Efficiency Limit of Photovoltaic Devices: Effect of Band Structure on Excited State Entropy Frank E. Osterloh* Department of Chemistry, University of CaliforniaDavis, One Shields

Osterloh, Frank

224

Unification of Field Theory and Maximum Entropy Methods for Learning Probability Densities  

E-Print Network [OSTI]

Bayesian field theory and maximum entropy are two methods for learning smooth probability distributions (a.k.a. probability densities) from finite sampled data. Both methods were inspired by statistical physics, but the relationship between them has remained unclear. Here I show that Bayesian field theory subsumes maximum entropy density estimation. In particular, the most common maximum entropy methods are shown to be limiting cases of Bayesian inference using field theory priors that impose no boundary conditions on candidate densities. This unification provides a natural way to test the validity of the maximum entropy assumption on one's data. It also provides a better-fitting nonparametric density estimate when the maximum entropy assumption is rejected.

Kinney, Justin B

2014-01-01T23:59:59.000Z

225

Near-Infrared, Kilosecond Variability of the Wisps And Jet in the Crab Pulsar Wind Nebula  

SciTech Connect (OSTI)

We present a time-lapse sequence of 20 near-infrared (J- and K'-band) snapshots of the central 20'' x 20'' of the Crab pulsar wind nebula, taken at sub-arcsecond resolution with the Hokupa'a/QUIRC adaptive optics camera on the Gemini North Telescope, and sampled at intervals of 10 minutes and 24 hours. It is observed that the equatorial wisps and polar knots in the termination shock of the pulsar wind appear to fluctuate in brightness on kilosecond time-scales. Maximum flux variations of {+-}24 {+-} 4 and {+-}14 {+-} 4 per cent relative to the mean (in 1.2 ks) are measured for the wisps and knots respectively, with greatest statistical significance in J band where the nebula background is less prominent. The J and K' flux densities imply different near-infrared spectra for the nonthermal continuum emission from the wisps and outermost polar knot (''sprite''), giving F{sub {nu}} {proportional_to} {nu}{sup -0.56{+-}0.12} and F{sub {nu}} {proportional_to} {nu}{sup -0.21{+-}0.13} respectively. The data are compared with existing optical and UV photometry and applied to constrain theories of the variability of the wisps (relativistic ion-cyclotron instability) and knots (relativistic fire hose instability).

Melatos, Andrew; Scheltus, D.; /Melbourne U.; Whiting, M.T.; /New South Wales U.; Eikenberry, S.S.; /Florida U.; Romani, R.W.; /Stanford U., Phys. Dept.; Rigaut, F.; /Gemini; Spitkovsky, A.; /KIPAC, Menlo Park; Arons, J.; /UC, Berkeley, Astron. Dept.; Payne, D.J.B.; /Melbourne U.

2006-01-11T23:59:59.000Z

226

Observing Healthcare Interior Environments and the Effect on Patient Behavior  

E-Print Network [OSTI]

variables in the interior environments that have the greatest impact, whether positive or negative, on patients. The methods used to perform this research include: inspections of the facility, observations, and surveys. By combining all of these methods...

Rice, Courtney R.

2010-07-14T23:59:59.000Z

227

Trapping and Frequency Variability in Electron Acoustic Waves  

E-Print Network [OSTI]

Trapping and Frequency Variability in Electron Acoustic Waves C.F. Driscoll, F. Anderegg, D 92093 USA Abstract. Electron Acoustic Waves (EAWs) with a phase velocity less than twice the plasma Langmuir waves, and at large excitations resonance is observed over a broad range. Laser Induced

California at San Diego, University of

228

WASTE SOLIDIFICATION BUILDING BENCH SCALE HIGH ACTIVITY WASTE SIMULANT VARIABILITY STUDY FY2008  

SciTech Connect (OSTI)

The primary objective of this task was to perform a variability study of the high activity waste (HAW) acidic feed to determine the impact of feed variability on the quality of the final grout and on the mixability of the salt solution into the dry powders. The HAW acidic feeds were processed through the neutralization/pH process, targeting a final pH of 12. These fluids were then blended with the dry materials to make the final waste forms. A secondary objective was to determine if elemental substitution for cost prohibitive or toxic elements in the simulant affects the mixing response, thus providing a more economical simulant for use in full scale tests. Though not an objective, the HAW simulant used in the full scale tests was also tested and compared to the results from this task. A statistically designed test matrix was developed based on the maximum molarity inputs used to make the acidic solutions. The maximum molarity inputs were: 7.39 HNO{sub 3}, 0.11618 gallium, 0.5423 silver, and 1.1032 'other' metals based on their NO{sub 3}{sup -} contribution. Substitution of the elements aluminum for gallium and copper for silver was also considered in this test matrix, resulting in a total of 40 tests. During the NaOH addition, the neutralization/pH adjustment process was controlled to a maximum temperature of 60 C. The neutralized/pH adjusted simulants were blended with Portland cement and zircon flour at a water to cement mass ratio of 0.30. The mass ratio of zircon flour to Portland cement was 1/12. The grout was made using a Hobart N-50 mixer running at low speed for two minutes to incorporate and properly wet the dry solids with liquid and at medium speed for five minutes for mixing. The resulting fresh grout was measured for three consecutive yield stress measurements. The cured grout was measured for set, bleed, and density. Given the conditions of preparing the grout in this task, all of the grouts were visually well mixed prior to preparing the grouts for measurements. All of the cured grouts were measured for bleed and set. All of the cured grouts satisfied the bleed and set requirements, where no bleed water was observed on any of the grout samples after one day and all had set within 3 days of curing. This data indicates, for a well mixed product, bleed and set requirement are satisfied for the range of acidic feeds tested in this task. The yield stress measurements provide both an indication on the mixability of the salt solution with dry materials and an indication of how quickly the grout is starting to form structure. The inability to properly mix these two streams into a well mixed grout product will lead to a non-homogeneous mixture that will impact product quality. Product quality issues could be unmixed regions of dry material and hot spots having high concentrations of americium 241. Mixes that were more difficult to incorporate typically resulted in grouts with higher yield stresses. The mixability from these tests will provide Waste Solidification Building (WSB) an indication of which grouts will be more challenging to mix. The first yield stress measurements were statistically compared to a list of variables, specifically the batched chemicals used to make the acidic solutions. The first yield stress was also compared to the physical properties of the acidic solutions, physical and pH properties of the neutralized/pH adjusted solutions, and chemical and physical properties of the grout.

Hansen, E; Timothy Jones, T; Tommy Edwards, T; Alex Cozzi, A

2009-03-20T23:59:59.000Z

229

OBSERVING CORONAL NANOFLARES IN ACTIVE REGION MOSS  

SciTech Connect (OSTI)

The High-resolution Coronal Imager (Hi-C) has provided Fe XII 193A images of the upper transition region moss at an unprecedented spatial ({approx}0.''3-0.''4) and temporal (5.5 s) resolution. The Hi-C observations show in some moss regions variability on timescales down to {approx}15 s, significantly shorter than the minute-scale variability typically found in previous observations of moss, therefore challenging the conclusion of moss being heated in a mostly steady manner. These rapid variability moss regions are located at the footpoints of bright hot coronal loops observed by the Solar Dynamics Observatory/Atmospheric Imaging Assembly in the 94 A channel, and by the Hinode/X-Ray Telescope. The configuration of these loops is highly dynamic, and suggestive of slipping reconnection. We interpret these events as signatures of heating events associated with reconnection occurring in the overlying hot coronal loops, i.e., coronal nanoflares. We estimate the order of magnitude of the energy in these events to be of at least a few 10{sup 23} erg, also supporting the nanoflare scenario. These Hi-C observations suggest that future observations at comparable high spatial and temporal resolution, with more extensive temperature coverage, are required to determine the exact characteristics of the heating mechanism(s).

Testa, Paola; DeLuca, Ed; Golub, Leon; Korreck, Kelly; Weber, Mark [Smithsonian Astrophysical Observatory, 60 Garden street, MS 58, Cambridge, MA 02138 (United States); De Pontieu, Bart; Martinez-Sykora, Juan; Title, Alan [Lockheed Martin Solar and Astrophysics Lab, Org. A021S, Bldg. 252, 3251 Hanover Street, Palo Alto, CA 94304 (United States); Hansteen, Viggo [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo (Norway); Cirtain, Jonathan; Winebarger, Amy; Kobayashi, Ken [NASA Marshall Space Flight Center, ZP 13, Huntsville, AL 35812 (United States); Kuzin, Sergey [P. N. Lebedev Physical institute of the Russian Academy of Sciences, Leninskii prospekt, 53, 119991 Moscow (Russian Federation); Walsh, Robert [University of Central Lancashire, Lancashire, Preston PR1 2HE (United Kingdom); DeForest, Craig, E-mail: ptesta@cfa.harvard.edu [Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States)

2013-06-10T23:59:59.000Z

230

Operating Reserves and Variable Generation  

SciTech Connect (OSTI)

This report tries to first generalize the requirements of the power system as it relates to the needs of operating reserves. It also includes a survey of operating reserves and how they are managed internationally in system operations today and then how new studies and research are proposing they may be managed in the future with higher penetrations of variable generation.

Ela, E.; Milligan, M.; Kirby, B.

2011-08-01T23:59:59.000Z

231

Setting the Renormalization Scale in QCD: The Principle of Maximum Conformality  

SciTech Connect (OSTI)

A key problem in making precise perturbative QCD predictions is the uncertainty in determining the renormalization scale {mu} of the running coupling {alpha}{sub s}({mu}{sup 2}): The purpose of the running coupling in any gauge theory is to sum all terms involving the {beta} function; in fact, when the renormalization scale is set properly, all non-conformal {beta} {ne} 0 terms in a perturbative expansion arising from renormalization are summed into the running coupling. The remaining terms in the perturbative series are then identical to that of a conformal theory; i.e., the corresponding theory with {beta} = 0. The resulting scale-fixed predictions using the 'principle of maximum conformality' (PMC) are independent of the choice of renormalization scheme - a key requirement of renormalization group invariance. The results avoid renormalon resummation and agree with QED scale-setting in the Abelian limit. The PMC is also the theoretical principle underlying the BLM procedure, commensurate scale relations between observables, and the scale-setting method used in lattice gauge theory. The number of active flavors nf in the QCD {beta} function is also correctly determined. We discuss several methods for determining the PMC/BLM scale for QCD processes. We show that a single global PMC scale, valid at leading order, can be derived from basic properties of the perturbative QCD cross section. The elimination of the renormalization scheme ambiguity using the PMC will not only increase the precision of QCD tests, but it will also increase the sensitivity of collider experiments to new physics beyond the Standard Model.

Brodsky, Stanley J.; /SLAC /Southern Denmark U., CP3-Origins; Di Giustino, Leonardo; /SLAC

2011-08-19T23:59:59.000Z

232

Nuclear-Powered Millisecond Pulsars and the Maximum Spin Frequency of Neutron Stars  

E-Print Network [OSTI]

Millisecond pulsars are neutron stars (NSs) that are thought to have been spun-up by mass accretion from a stellar companion. It is unknown whether there is a natural brake for this process, or if it continues until the centrifugal breakup limit is reached at submillisecond periods. Many NSs that are accreting from a companion exhibit thermonuclear X-ray bursts that last tens of seconds, caused by unstable nuclear burning on their surfaces. Millisecond brightness oscillations during bursts from ten NSs (as distinct from other rapid X-ray variability that is also observed) are thought to measure the stellar spin, but direct proof of a rotational origin has been lacking. Here, we report the detection of burst oscillations at the known spin frequency of an accreting millisecond pulsar, and we show that these oscillations always have the same rotational phase. This firmly establishes burst oscillations as nuclear-powered pulsations tracing the spin of accreting NSs, corroborating earlier evidence. The distribution of spin frequencies of the 11 nuclear-powered pulsars cuts off well below the breakup frequency for most NS models, supporting theoretical predictions that gravitational radiation losses can limit accretion torques in spinning up millisecond pulsars.

Deepto Chakrabarty; Edward H. Morgan; Michael P. Muno; Duncan K. Galloway; Rudy Wijnands; Michiel van der Klis; Craig B. Markwardt

2003-07-01T23:59:59.000Z

233

Dynamical dark energy or variable cosmological parameters?  

E-Print Network [OSTI]

One of the main aims in the next generation of precision cosmology experiments will be an accurate determination of the equation of state (EOS) for the dark energy (DE). If the latter is dynamical, the resulting barotropic index \\omega should exhibit a non-trivial evolution with the redshift. Usually this is interpreted as a sign that the mechanism responsible for the DE is related to some dynamical scalar field, and in some cases this field may behave non-canonically (phantom field). Present observations seem to favor an evolving DE with a potential phantom phase near our time. In the literature there is a plethora of dynamical models trying to describe this behavior. Here we show that the simplest option, namely a model with a variable cosmological term, \\Lambda=\\Lambda(t), leads in general to a non-trivial effective EOS, with index \\omega_e, which may naturally account for these data features. We prove that in this case there is always a ``crossing'' of the \\omega_e=-1 barrier near our time. We also show how this effect is modulated (or even completely controled) by a variable Newton's constant G=G(t).

Joan Sola; Hrvoje Stefancic

2005-12-21T23:59:59.000Z

234

Microcontroller Servomotor for Maximum Effective Power Point for Solar Cell System  

E-Print Network [OSTI]

In this paper a Maximum Power point (MPP) tracking algorithm is developed using dual-axis servomotor feedback tracking control system. An efficient and accurate servomotor system is used to increase the system efficiency and reduces the solar cell...

Al-Khalidy, M.; Al-Rawi, O.; Noaman, N.

2010-01-01T23:59:59.000Z

235

Achieving Consistent Maximum Brake Torque with Varied Injection Timing in a DI Diesel Engine  

E-Print Network [OSTI]

, the characteristics of combustion for swept injection timings along the maximum brake torque plateau are determined. The research is conducted by varying injection timing at constant engine speed and load while measuring engine emissions and in-cylinder pressure...

Kroeger, Timothy H

2013-09-19T23:59:59.000Z

236

Delay Analysis of Maximum Weight Scheduling in Wireless Ad Hoc Networks  

E-Print Network [OSTI]

This paper studies delay properties of the well-known maximum weight scheduling algorithm in wireless ad hoc networks. We consider wireless networks with either one-hop or multihop flows. Specifically, this paper shows ...

Modiano, Eytan H.

237

Dynamical Reconstruction of Upper-Ocean Conditions in the Last Glacial Maximum Atlantic  

E-Print Network [OSTI]

Proxies indicate that the Last Glacial Maximum (LGM) Atlantic Ocean was marked by increased meridional and zonal near sea surface temperature gradients relative to today. Using a least squares fit of a full general circulation ...

Wunsch, Carl

238

Atlantic Ocean circulation at the last glacial maximum : inferences from data and models  

E-Print Network [OSTI]

This thesis focuses on ocean circulation and atmospheric forcing in the Atlantic Ocean at the Last Glacial Maximum (LGM, 18-21 thousand years before present). Relative to the pre-industrial climate, LGM atmospheric CO? ...

Dail, Holly Janine

2012-01-01T23:59:59.000Z

239

Submodule Integrated Distributed Maximum Power Point Tracking for Solar Photovoltaic Applications  

E-Print Network [OSTI]

This paper explores the benefits of distributed power electronics in solar photovoltaic applications through the use of submodule integrated maximum power point trackers (MPPT). We propose a system architecture that provides ...

Pilawa-Podgurski, Robert C. N.

240

Acoustic Space Dimensionality Selection and Combination using the Maximum Entropy Principle  

E-Print Network [OSTI]

In this paper we propose a discriminative approach to acoustic space dimensionality selection based on maximum entropy modelling. We form a set of constraints by composing the acoustic space with the space of phone classes, and use a continuous...

Abdel-Haleem, Yasser H; Renals, Steve; Lawrence, Neil D

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Author's personal copy Unified behaviour of maximum soot yields of methane, ethane and propane  

E-Print Network [OSTI]

Author's personal copy Unified behaviour of maximum soot yields of methane, ethane and propane the current study and the previous measurements in similar flames with methane, ethane, and propane flames

Gülder, ?mer L.

242

Variable Interactions in Query-Driven Visualization  

SciTech Connect (OSTI)

One fundamental element of scientific inquiry is discoveringrelationships, particularly the interactions between different variablesin observed or simulated phenomena. Building upon our prior work in thefield of Query-Driven Visualization, where visual data analysisprocessing is focused on subsets of large data deemed to be"scientifically interesting," this new work focuses on a novel knowledgediscovery capability suitable for use with petascale class datasets. Itenables visual presentation of the presence or absence of relationships(correlations) between variables in data subsets produced by Query-Drivenmethodologies. This technique holds great potential for enablingknowledge discovery from large and complex datasets currently emergingfrom SciDAC and INCITE projects. It is sufficiently generally to beapplicable to any time of complex, time-varying, multivariate data fromstructured, unstructured or adaptive grids.

Bethel, E. Wes; Gosink, Luke J.; Anderson, John C.; Joy, Kenneth I.

2007-10-25T23:59:59.000Z

243

A stochastic model for sediment yield using the Principle of Maximum Entropy  

E-Print Network [OSTI]

WATER RESOURCES RESEARCH, VOL. 23, NO. 5, PAGES 781-793, MAY 1987 A Stochastic Model for Sediment Yield Using the Principle of Maximum Entropy V. P. SINGH AND P. F. KRSTANOVIC Department of Civil Engineering, Louisiana State University, Baton... Rouge The principle of maximum entropy was applied to derive a stochastic model for sediment yield from upland watersheds. By maximizing the conditional entropy subject to certain constraints, a probability distribution of sediment yield conditioned...

Singh, V. P.; Krstanovic, P. F.

244

A comparison of light and velocity variations in Semiregular variables  

E-Print Network [OSTI]

NIR velocity variations are compared with simultaneous visual light curves for a sample of late-type semiregular variables (SRV). Precise radial velocity measurements are also presented for the SRV V450 Aql. Our aim is to investigate the nature of the irregular light changes found in these variables. Light and velocity variations are correlated in all stars of our sample. Based on these results we discuss several possibilities to explain the observed behavior. We find that pulsation is responsible for large amplitude variations. In a recent paper Lebzelter (1999) invoked large convective cells to understand observed velocity variations. This possibility is discussed with respect to the observed correlation between light and velocity changes. In the light of these results we investigate the origin of the semiregular variations.

T. Lebzelter; L. L. Kiss; K. H. Hinkle

2000-09-21T23:59:59.000Z

245

Interrelationships among alternative export variables and their impacts on corn prices  

E-Print Network [OSTI]

export variable. Corn export sales data (collected by USDA since 1973) provide an additional source of information on export movements, thus offering an alternative export demand indicator. Data on commercial stocks at terminals and port elevators...). The primary objective of this study was to assess the impacts of these alternative export variables (sales, stocks, and shipments) on corn prices, and to investigate the dynamic interrelationships among these variables. The observations were carried out...

Clarke, Somkid Tammakrut

1987-01-01T23:59:59.000Z

246

Heterogeneity-corrected vs -uncorrected critical structure maximum point doses in breast balloon brachytherapy  

SciTech Connect (OSTI)

Recent studies have reported potentially clinically meaningful dose differences when heterogeneity correction is used in breast balloon brachytherapy. In this study, we report on the relationship between heterogeneity-corrected and -uncorrected doses for 2 commonly used plan evaluation metrics: maximum point dose to skin surface and maximum point dose to ribs. Maximum point doses to skin surface and ribs were calculated using TG-43 and Varian Acuros for 20 patients treated with breast balloon brachytherapy. The results were plotted against each other and fit with a zero-intercept line. Max skin dose (Acuros) = max skin dose (TG-43) ? 0.930 (R{sup 2} = 0.995). The average magnitude of difference from this relationship was 1.1% (max 2.8%). Max rib dose (Acuros) = max rib dose (TG-43) ? 0.955 (R{sup 2} = 0.9995). The average magnitude of difference from this relationship was 0.7% (max 1.6%). Heterogeneity-corrected maximum point doses to the skin surface and ribs were proportional to TG-43-calculated doses. The average deviation from proportionality was 1%. The proportional relationship suggests that a different metric other than maximum point dose may be needed to obtain a clinical advantage from heterogeneity correction. Alternatively, if maximum point dose continues to be used in recommended limits while incorporating heterogeneity correction, institutions without this capability may be able to accurately estimate these doses by use of a scaling factor.

Kim, Leonard, E-mail: kimlh@umdnj.edu [Department of Radiation Oncology, Cancer Institute of New Jersey, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, New Brunswick, NJ (United States); Narra, Venkat; Yue, Ning [Department of Radiation Oncology, Cancer Institute of New Jersey, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, New Brunswick, NJ (United States)

2013-07-01T23:59:59.000Z

247

Variable frequency microwave heating apparatus  

DOE Patents [OSTI]

A variable frequency microwave heating apparatus (10) designed to allow modulation of the frequency of the microwaves introduced into a multi-mode microwave cavity (34) for testing or other selected applications. The variable frequency microwave heating apparatus (10) includes a microwave signal generator (12) and a high-power microwave amplifier (20) or a high-power microwave oscillator (14). A power supply (22) is provided for operation of the high-power microwave oscillator (14) or microwave amplifier (20). A directional coupler (24) is provided for detecting the direction and amplitude of signals incident upon and reflected from the microwave cavity (34). A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load (28).

Bible, Don W. (Clinton, TN); Lauf, Robert J. (Oak Ridge, TN); Johnson, Arvid C. (Lake in the Hills, IL); Thigpen, Larry T. (Angier, NC)

1999-01-01T23:59:59.000Z

248

Massive Variability Surveys from Venezuela  

E-Print Network [OSTI]

At the Venezuela National Astronomical Observatory we are carrying out variability surveys spanning many hundreds of square degrees near the celestial equator, using an 8k x 8k CCD Mosaic Camera optimized for drift-scanning on a 1m Schmidt telescope. Among the initial efforts was a project to obtain the first moderately deep, homogeneous sample of young stars over an area of ~180sqr.deg. encompassing the entire Orion OB1 association, one of the nearest and most active regions of star formation. The results show that variability is a powerful technique to identify pre-main sequence populations, specially in sparse areas devoid of gas and dust. We are currently developing a massive database, equipped with web-based data mining tools, that will make our data and results available to the astronomical community.

Cesar Briceno

2003-04-03T23:59:59.000Z

249

On the near infrared variability of chemically peculiar stars  

E-Print Network [OSTI]

Some CP stars have recently been discovered by Catalano et al. (1991) to be variable also in the near infrared, although with smaller amplitudes than in the visible. Hence an observational campaign was started in which the infrared light variability of a number of CP2 and CP4 stars has been investigated at the ESO-La Silla Observatory in the bands J, H, and K. As a general result, infrared variations show the same behavior in all three filters but amplitudes are smaller than in the visible.

F. A. Catalano; F. Leone

1998-05-06T23:59:59.000Z

250

Review of Probability Random Variable  

E-Print Network [OSTI]

at close 4) Height of wheel going over a rocky road #12;3 Random Variable Non-examples 1) `Heads' or `Tails' on coin 2) Red or Black ball from urn But we can make these into RV's Basic Idea ­ don't know · Temperature · Wheel height #12;5 Given Continuous RV X... What is the probability that X = x0 ? Oddity : P

Fowler, Mark

251

Imprecise Reliability Assessment and Decision-Making when the Type of the Probability Distribution of the Random Variables is  

E-Print Network [OSTI]

the upper and lower bounds of the reliability of a system involving such variables. A method for modeling, is formulated and solved in order to estimate the minimum and maximum values of a system's reliability1 Imprecise Reliability Assessment and Decision-Making when the Type of the Probability

Nikolaidis, Efstratios

252

X-RAYRICH GAMMA-RAY BURSTS, PHOTOSPHERES, AND VARIABILITY P. Meszaros,1,2  

E-Print Network [OSTI]

X-RAY­RICH GAMMA-RAY BURSTS, PHOTOSPHERES, AND VARIABILITY P. Me´sza´ros,1,2 E. Ramirez-Ruiz,3 M. J of the observational gamma-ray variability-luminosity relation. Subject headings: gamma rays: bursts -- radiation mechanisms: nonthermal 1. INTRODUCTION Gamma-ray burst (GRB) light curves at gamma-ray ener- gies are often

Zhang, Bing

253

Variable flexure-based fluid filter  

DOE Patents [OSTI]

An apparatus and method for filtering particles from a fluid comprises a fluid inlet, a fluid outlet, a variable size passage between the fluid inlet and the fluid outlet, and means for adjusting the size of the variable size passage for filtering the particles from the fluid. An inlet fluid flow stream is introduced to a fixture with a variable size passage. The size of the variable size passage is set so that the fluid passes through the variable size passage but the particles do not pass through the variable size passage.

Brown, Steve B.; Colston Jr., Billy W.; Marshall, Graham; Wolcott, Duane

2007-03-13T23:59:59.000Z

254

Statistical issues in Mendelian randomization: use of genetic instrumental variables for assessing causal associations  

E-Print Network [OSTI]

HWE HardyWeinberg equilibrium I(L)OR individual (log) odds ratio IL6 interleukin-6 IPD individual participant data IV instrumental variable LIML limited information maximum likelihood LD linkage disequilibrium LDL-C low-density lipoprotein cholesterol... (L)OR marginal (log) odds ratio P(L)OR population (log) odds ratio RCT randomized controlled trial SE standard error (G)SMM (generalized) structural mean model SNP single nucleotide polymorphism Abbreviations for the various studies in the CCGC are given...

Burgess, Stephen

2012-03-06T23:59:59.000Z

255

arXiv:cs.CC/0508071 Every decision tree has an influential variable  

E-Print Network [OSTI]

. A deter­ ministic decision tree (DDT) for a boolean function f : f1; 1g n ! f1; 1g is a deterministic in Section 3.1). The cost of a DDT on a given input is simply the number of input variables that it reads, and the DDT complexity of a func­ tion f , D(f), is the minimum over all DDT's for f of the maximum cost

Servedio, Rocco

256

Observables of Macdonald processes  

E-Print Network [OSTI]

We present a framework for computing averages of various observables of Macdonald processes. This leads to new contour--integral formulas for averages of a large class of multilevel observables, as well as Fredholm determinants for averages of two different single level observables.

Alexei Borodin; Ivan Corwin; Vadim Gorin; Shamil Shakirov

2013-06-04T23:59:59.000Z

257

Methoden Wetenschappelijk and Observational  

E-Print Network [OSTI]

Methoden Wetenschappelijk Onderzoek Fact-free and Observational Science #12;Data · Part of modern science is based on observation ­How do we do this? ­And what are the pitfalls? · Knowing how to observe is an important step in experimental design #12;Three kinds of science · There are (in my view) three ways

Steels, Luc

258

Removing the Microlensing Blending-Parallax Degeneracy Using Source Variability  

E-Print Network [OSTI]

Microlensing event MACHO 97-SMC-1 is one of the rare microlensing events for which the source is a variable star, simply because most variable stars are systematically eliminated from microlensing studies. Using observational data for this event, we show that the intrinsic variability of a microlensed star is a powerful tool to constrain the nature of the lens by breaking the degeneracy between the microlens parallax and the blended light. We also present a statistical test for discriminating the location of the lens based on the \\chi^2 contours of the vector \\Lambda, the inverse of the projected velocity. We find that while SMC self lensing is somewhat favored, neither location can be ruled out with good confidence.

Assef, R J; Afonso, C; Albert, J N; Andersen, J; Ansari, R; Aubourg, E; Bareyre, P; Beaulieu, J P; Charlot, X; Coutures, C; Ferlet, R; Fouqu, P; Glicenstein, J F; Goldman, B; Graff, D; Gros, M; Hassinski, J; Hamadache, C; De Kat, J; Le Guillou, Laurent; Lesquoy, E; Loup, C; Magneville, C; Marquette, J B; Maurice, E; Maury, A; Milsztajn, A; Moniez, M; Palanque-Delabrouille, Nathalie; Perdereau, O; Rahal, Y R; Rich, J; Spiro, M; Tisserand, P; Vidal-Madjar, A; Vigroux, L; Zylberajch, S; Bennett, D P; Becker, A C; Griest, K; Vandehei, T; Welch, D L; Udalski, A; Szymanski, M K; Kubiak, M; Pietrzynski, G; Soszynski, I; Szewczyk, O; Wyrzykowski, L

2006-01-01T23:59:59.000Z

259

The role of an accretion disk in AGN variability  

E-Print Network [OSTI]

Optically thick accretion disks are considered to be important ingredients of luminous AGN. The claim of their existence is well supported by observations and recent years brought some progress in understanding of their dynamics. However, the role of accretion disks in optical/UV/X-ray variability of AGN is not quite clear. Most probably, in short timescales the disk reprocesses the variable X-ray flux but at longer timescales the variations of the disk structure lead directly to optical/UV variations as well as affect, or even create, the X-ray variability pattern. We urgently need a considerable progress in time-dependent disk models to close the gap between the theory and the stream of data coming from the AGN monitoring.

B. Czerny

2004-09-10T23:59:59.000Z

260

Switching characteristics and maximum repetitive frequency of InGaAsP/InP bistable injection lasers  

SciTech Connect (OSTI)

Switching characteristics of nonuniformly pumped InGaAsP/InP BH Structure bistable lasers are investigated both experimentally and theoretically. First observation of automatic turn-on phenomenon was made, which is found to be a random process. For repetitive operation, turn-on delay time and necessary duration of switch-off pulse practically limited the maximum repetitive frequency. For ''switch-on,'' triggering the saturable absorption region is more effective. For reducing the minimum switch-off pulse width, either higher doping or reverse biasing at the absorption region is recommended. Tradeoff relation of OFF pulse width with threshold current and stable operation are discussed. With some improvements in device parameters, bistable operation at repetitive frequency over 1 GHz is expected.

Liu, H.F.; Hashimoto, Y.; Kamiya, T.

1988-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Variable area light reflecting assembly  

DOE Patents [OSTI]

Device for tracking daylight and projecting it into a building. The device tracks the sun and automatically adjusts both the orientation and area of the reflecting surface. The device may be mounted in either a wall or roof of a building. Additionally, multiple devices may be employed in a light shaft in a building, providing daylight to several different floors. The preferred embodiment employs a thin reflective film as the reflecting device. One edge of the reflective film is fixed, and the opposite end is attached to a spring-loaded take-up roller. As the sun moves across the sky, the take-up roller automatically adjusts the angle and surface area of the film. Additionally, louvers may be mounted at the light entrance to the device to reflect incoming daylight in an angle perpendicular to the device to provide maximum reflective capability when daylight enters the device at non-perpendicular angles.

Howard, Thomas C. (Raleigh, NC)

1986-01-01T23:59:59.000Z

262

Variable area light reflecting assembly  

DOE Patents [OSTI]

Device is described for tracking daylight and projecting it into a building. The device tracks the sun and automatically adjusts both the orientation and area of the reflecting surface. The device may be mounted in either a wall or roof of a building. Additionally, multiple devices may be employed in a light shaft in a building, providing daylight to several different floors. The preferred embodiment employs a thin reflective film as the reflecting device. One edge of the reflective film is fixed, and the opposite end is attached to a spring-loaded take-up roller. As the sun moves across the sky, the take-up roller automatically adjusts the angle and surface area of the film. Additionally, louvers may be mounted at the light entrance to the device to reflect incoming daylight in an angle perpendicular to the device to provide maximum reflective capability when daylight enters the device at non-perpendicular angles. 9 figs.

Howard, T.C.

1986-12-23T23:59:59.000Z

263

On the maximum value of the cosmic abundance of oxygen and the oxygen yield  

E-Print Network [OSTI]

We search for the maximum oxygen abundance in spiral galaxies. Because this maximum value is expected to occur in the centers of the most luminous galaxies, we have constructed the luminosity - central metallicity diagram for spiral galaxies, based on a large compilation of existing data on oxygen abundances of HII regions in spiral galaxies. We found that this diagram shows a plateau at high luminosities (-22.3 oxygen abundance 12+log(O/H) ~ 8.87. This provides strong evidence that the oxygen abundance in the centers of the most luminous metal-rich galaxies reaches the maximum attainable value of oxygen abundance. Since some fraction of the oxygen (about 0.08 dex) is expected to be locked into dust grains, the maximum value of the true gas+dust oxygen abundance in spiral galaxies is 12+log(O/H) ~ 8.95. This value is a factor of ~ 2 higher than the recently estimated solar value. Based on the derived maximum oxygen abundance in galaxies, we found the oxygen yield to be about 0.0035, depending on the fraction of oxygen incorporated into dust grains.

L. S. Pilyugin; T. X. Thuan; J. M. Vilchez

2007-01-11T23:59:59.000Z

264

HFIR Vessel Maximum Permissible Pressures for Operating Period 26 to 50 EFPY (100 MW)  

SciTech Connect (OSTI)

Extending the life of the HFIR pressure vessel from 26 to 50 EFPY (100 MW) requires an updated calculation of the maximum permissible pressure for a range in vessel operating temperatures (40-120 F). The maximum permissible pressure is calculated using the equal-potential method, which takes advantage of knowledge gained from periodic hydrostatic proof tests and uses the test conditions (pressure, temperature, and frequency) as input. The maximum permissible pressure decreases with increasing time between hydro tests but is increased each time a test is conducted. The minimum values that occur just prior to a test either increase or decrease with time, depending on the vessel temperature. The minimum value of these minimums is presently specified as the maximum permissible pressure. For three vessel temperatures of particular interest (80, 88, and 110 F) and a nominal time of 3.0 EFPY(100 MVV)between hydro tests, these pressures are 677, 753, and 850 psi. For the lowest temperature of interest (40 F), the maximum permissible pressure is 295 psi.

Cheverton, R.D.; Inger, J.R.

1999-01-01T23:59:59.000Z

265

Variable Average Absolute Percent Differences  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism inS-4500II FieldVacancy-InducedCloudPoissonVampire Power1 -Variable

266

Variable Mass Theories of Gravity  

E-Print Network [OSTI]

Several attempts to construct theories of gravity with variable mass are considered. The theoretical impacts of allowing the rest mass to vary with respect to time or an appropriate curve parameter are examined in the framework of Newtonian and Einsteinian gravity theories. In further steps, scalar-tensor theories are examined with respect to their relation to the variation of the mass and in an ultimate step, an additional coordinate is introduced and its possible relation to the mass is examined, yielding a five dimensional space-time-matter theory.

M. Leclerc

2002-12-03T23:59:59.000Z

267

White dwarf masses in cataclysmic variables  

E-Print Network [OSTI]

The white dwarf (WD) mass distribution of cataclysmic variables (CVs) has recently been found to dramatically disagree with the predictions of the standard CV formation model. The high mean WD mass among CVs is not imprinted in the currently observed sample of CV progenitors and cannot be attributed to selection effects. Two possibilities have been put forward: either the WD grows in mass during CV evolution, or in a significant fraction of cases, CV formation is preceded by a (short) phase of thermal time-scale mass transfer (TTMT) in which the WD gains a sufficient amount of mass. We investigate if either of these two scenarios can bring theoretical predictions and observations into agreement. We employed binary population synthesis models to simulate the present intrinsic CV population. We incorporated aspects specific to CV evolution such as an appropriate mass-radius relation of the donor star and a more detailed prescription for the critical mass ratio for dynamically unstable mass transfer. We also imp...

Wijnen, T P G; Schreiber, M R

2015-01-01T23:59:59.000Z

268

Utility Variable Generation Integration Group Fall Technical...  

Broader source: Energy.gov (indexed) [DOE]

Technical Workshop Utility Variable Generation Integration Group Fall Technical Workshop October 15, 2014 9:00AM CDT to October 17, 2014 3:00PM CDT The Utility Variable Generation...

269

Fast singular value decomposition combined maximum entropy method for plasma tomography  

SciTech Connect (OSTI)

The maximum entropy method (MEM) is a widely used reconstruction algorithm in plasma physics. Drawbacks of the conventional MEM are its heavy time-consuming process and possible generation of noisy reconstruction results. In this article, a modified maximum entropy algorithm is described which speeds up the calculation and shows better noise handling capability. Similar to the rapid minimum Fisher information method, the modified maximum entropy algorithm uses simple matrix operations instead of treating a fully nonlinear problem. The preprocess for rapid tomographic calculation is based on the vector operations and the singular value decomposition (SVD). The initial guess of the sought-for emissivity is calculated by SVD and this helped reconstruction about ten times faster than the conventional MEM. Therefore, the developed fast MEM can be used for intershot tomographic analyses of fusion plasmas.

Kim, Junghee; Choe, W. [Department of Physics, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701(Korea, Republic of)

2006-02-15T23:59:59.000Z

270

Variable-amplitude oscillatory shear response of amorphous materials  

E-Print Network [OSTI]

Variable-amplitude oscillatory shear tests are emerging as powerful tools to investigate and quantify the nonlinear rheology of amorphous solids, complex fluids and biological materials. Quite a few recent experimental and atomistic simulation studies demonstrated that at low shear amplitudes, an amorphous solid settles into an amplitude- and initial conditions-dependent dissipative limit cycle, in which back-and-forth localized particle rearrangements periodically bring the system to the same state. At sufficiently large shear amplitudes, the amorphous system loses memory of the initial conditions, exhibits chaotic particle motions accompanied by diffusive behavior and settles into a stochastic steady-state. The two regimes are separated by a transition amplitude, possibly characterized by some critical-like features. Here we argue that these observations support some of the physical assumptions embodied in the nonequilibrium thermodynamic, internal-variables based, Shear-Transformation-Zone model of amorphous visco-plasticity; most notably that "flow defects" in amorphous solids are characterized by internal states between which they can make transitions, and that structural evolution is driven by dissipation associated with plastic deformation. We present a rather extensive theoretical analysis of the thermodynamic Shear-Transformation-Zone model for a variable-amplitude oscillatory shear protocol, highlighting its success in accounting for various experimental and simulational observations, as well as its limitations. Our results offer a continuum-level theoretical framework for interpreting the variable-amplitude oscillatory shear response of amorphous solids and may promote additional developments.

Nathan Perchikov; Eran Bouchbinder

2014-04-13T23:59:59.000Z

271

Variable frequency microwave furnace system  

DOE Patents [OSTI]

A variable frequency microwave furnace system (10) designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity (34) for testing or other selected applications. The variable frequency microwave furnace system (10) includes a microwave signal generator (12) or microwave voltage-controlled oscillator (14) for generating a low-power microwave signal for input to the microwave furnace. A first amplifier (18) may be provided to amplify the magnitude of the signal output from the microwave signal generator (12) or the microwave voltage-controlled oscillator (14). A second amplifier (20) is provided for processing the signal output by the first amplifier (18). The second amplifier (20) outputs the microwave signal input to the furnace cavity (34). In the preferred embodiment, the second amplifier (20) is a traveling-wave tube (TWT). A power supply (22) is provided for operation of the second amplifier (20). A directional coupler (24) is provided for detecting the direction of a signal and further directing the signal depending on the detected direction. A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load (28).

Bible, Don W. (Clinton, TN); Lauf, Robert J. (Oak Ridge, TN)

1994-01-01T23:59:59.000Z

272

Variable frequency microwave furnace system  

DOE Patents [OSTI]

A variable frequency microwave furnace system designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity for testing or other selected applications. The variable frequency microwave furnace system includes a microwave signal generator or microwave voltage-controlled oscillator for generating a low-power microwave signal for input to the microwave furnace. A first amplifier may be provided to amplify the magnitude of the signal output from the microwave signal generator or the microwave voltage-controlled oscillator. A second amplifier is provided for processing the signal output by the first amplifier. The second amplifier outputs the microwave signal input to the furnace cavity. In the preferred embodiment, the second amplifier is a traveling-wave tube (TWT). A power supply is provided for operation of the second amplifier. A directional coupler is provided for detecting the direction of a signal and further directing the signal depending on the detected direction. A first power meter is provided for measuring the power delivered to the microwave furnace. A second power meter detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load. 5 figs.

Bible, D.W.; Lauf, R.J.

1994-06-14T23:59:59.000Z

273

Estimating the maximum potential revenue for grid connected electricity storage : arbitrage and regulation.  

SciTech Connect (OSTI)

The valuation of an electricity storage device is based on the expected future cash ow generated by the device. Two potential sources of income for an electricity storage system are energy arbitrage and participation in the frequency regulation market. Energy arbitrage refers to purchasing (stor- ing) energy when electricity prices are low, and selling (discharging) energy when electricity prices are high. Frequency regulation is an ancillary service geared towards maintaining system frequency, and is typically procured by the independent system operator in some type of market. This paper outlines the calculations required to estimate the maximum potential revenue from participating in these two activities. First, a mathematical model is presented for the state of charge as a function of the storage device parameters and the quantities of electricity purchased/sold as well as the quantities o ered into the regulation market. Using this mathematical model, we present a linear programming optimization approach to calculating the maximum potential revenue from an elec- tricity storage device. The calculation of the maximum potential revenue is critical in developing an upper bound on the value of storage, as a benchmark for evaluating potential trading strate- gies, and a tool for capital nance risk assessment. Then, we use historical California Independent System Operator (CAISO) data from 2010-2011 to evaluate the maximum potential revenue from the Tehachapi wind energy storage project, an American Recovery and Reinvestment Act of 2009 (ARRA) energy storage demonstration project. We investigate the maximum potential revenue from two di erent scenarios: arbitrage only and arbitrage combined with the regulation market. Our analysis shows that participation in the regulation market produces four times the revenue compared to arbitrage in the CAISO market using 2010 and 2011 data. Then we evaluate several trading strategies to illustrate how they compare to the maximum potential revenue benchmark. We conclude with a sensitivity analysis with respect to key parameters.

Byrne, Raymond Harry; Silva Monroy, Cesar Augusto.

2012-12-01T23:59:59.000Z

274

INTEGRAL observations of HER X-1  

E-Print Network [OSTI]

First results of observations of the low mass X-ray binary Her X-1/HZ Her performed by the INTEGRAL satellite in July-August 2005 are presented. A significant part of one 35 day main-on state was covered. The cyclotron line in the X-ray spectrum is well observed and its position and shape, as well as its variability with time and phase of the 1.24 s pulsation are explored. X-ray pulse profiles for different energy bands are studied throughout the observation. The pulse period is found to vary on short time scales revealing a dynamical spin-up/spin-down behavior. Results of simultaneous optical observations of HZ Her are also discussed.

D. Klochkov; R. Staubert; S. Tsygankov; A. Lutovinov; K. P. Postnov; N. I. Shakura; S. A. Potanin; C. Ferrigno; I. Kreykenbohm; J. Wilms

2007-04-23T23:59:59.000Z

275

Study on Two Optimization Problems: Line Cover and Maximum Genus Embedding  

E-Print Network [OSTI]

STUDY ON TWO OPTIMIZATION PROBLEMS: LINE COVER AND MAXIMUM GENUS EMBEDDING A Thesis by CHENG CAO Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment of the requirements for the degree of MASTER OF SCIENCE... May 2012 Major Subject: Computer Science STUDY ON TWO OPTIMIZATION PROBLEMS: LINE COVER AND MAXIMUM GENUS EMBEDDING A Thesis by CHENG CAO Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment...

Cao, Cheng

2012-07-16T23:59:59.000Z

276

What is the maximum rate at which entropy of a string can increase?  

SciTech Connect (OSTI)

According to Susskind, a string falling toward a black hole spreads exponentially over the stretched horizon due to repulsive interactions of the string bits. In this paper such a string is modeled as a self-avoiding walk and the string entropy is found. It is shown that the rate at which information/entropy contained in the string spreads is the maximum rate allowed by quantum theory. The maximum rate at which the black hole entropy can increase when a string falls into a black hole is also discussed.

Ropotenko, Kostyantyn [State Administration of Communications, Ministry of Transport and Communications of Ukraine 22, Khreschatyk, 01001, Kyiv (Ukraine)

2009-03-15T23:59:59.000Z

277

Hydrodynamic Relaxation of an Electron Plasma to a Near-Maximum Entropy State  

SciTech Connect (OSTI)

Dynamical relaxation of a pure electron plasma in a Malmberg-Penning trap is studied, comparing experiments, numerical simulations and statistical theories of weakly dissipative two-dimensional (2D) turbulence. Simulations confirm that the dynamics are approximated well by a 2D hydrodynamic model. Statistical analysis favors a theoretical picture of relaxation to a near-maximum entropy state with constrained energy, circulation, and angular momentum. This provides evidence that 2D electron fluid relaxation in a turbulent regime is governed by principles of maximum entropy.

Rodgers, D. J.; Servidio, S.; Matthaeus, W. H.; Mitchell, T. B.; Aziz, T. [Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716 (United States); Montgomery, D. C. [Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755 (United States)

2009-06-19T23:59:59.000Z

278

Maximum-Entropy Closures for Kinetic Theories of Neuronal Network Dynamics  

SciTech Connect (OSTI)

We analyze (1+1)D kinetic equations for neuronal network dynamics, which are derived via an intuitive closure from a Boltzmann-like equation governing the evolution of a one-particle (i.e., one-neuron) probability density function. We demonstrate that this intuitive closure is a generalization of moment closures based on the maximum-entropy principle. By invoking maximum-entropy closures, we show how to systematically extend this kinetic theory to obtain higher-order (1+1)D kinetic equations and to include coupled networks of both excitatory and inhibitory neurons.

Rangan, Aaditya V.; Cai, David [Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States)

2006-05-05T23:59:59.000Z

279

Maximum Entropy Models of Shortest Path and Outbreak Distributions in Networks  

E-Print Network [OSTI]

Properties of networks are often characterized in terms of features such as node degree distributions, average path lengths, diameters, or clustering coefficients. Here, we study shortest path length distributions. On the one hand, average as well as maximum distances can be determined therefrom; on the other hand, they are closely related to the dynamics of network spreading processes. Because of the combinatorial nature of networks, we apply maximum entropy arguments to derive a general, physically plausible model. In particular, we establish the generalized Gamma distribution as a continuous characterization of shortest path length histograms of networks or arbitrary topology. Experimental evaluations corroborate our theoretical results.

Bauckhage, Christian; Hadiji, Fabian

2015-01-01T23:59:59.000Z

280

On the Vertical Decay Rate of the Maximum Tangential Winds in Tropical Cyclones DANIEL P. STERN* AND DAVID S. NOLAN  

E-Print Network [OSTI]

On the Vertical Decay Rate of the Maximum Tangential Winds in Tropical Cyclones DANIEL P. STERN independent of both the maximum wind speed and the radius of maximum winds (RMW). This can be seen winds change with height. Above 2-km height, vertical profiles of Vmaxnorm are nearly independent

Nolan, David S.

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Periodic photometric variability of the brown dwarf Kelu-1  

E-Print Network [OSTI]

We have detected a strong periodicity of 1.80+/-0.05 hours in photometric observations of the brown dwarf Kelu-1. The peak-to-peak amplitude of the variation is ~1.1% (11.9+/-0.8 mmag) in a 41nm wide filter centred on 857nm and including the dust/temperature sensitive TiO & CrH bands. We have identified two plausible causes of variability: surface features rotating into- and out-of-view and so modulating the light curve at the rotation period; or, elliposidal variability caused by an orbiting companion. In the first scenario, we combine the observed vsin(i) of Kelu-1 and standard model radius to determine that the axis of rotation is inclined at 65+/-12 degrees to the line of sight.

F. J. Clarke; C. G. Tinney; K. R. Covey

2002-01-10T23:59:59.000Z

282

Observational learning in horses  

E-Print Network [OSTI]

OBSERVATIONAL LEARNING IN HORSES A Thesis by KATHERINE LOUISE BAER Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE May 1979 Major Subject: Animal... Science OBSERVATIONAL LEARNING IN HORSES A Thesis by KATHERINE LOUISE BAER Approved as to style and content by: L7 . 5+~ (Chairma of . C mmittee) ) c r (Mem ) YiNicc CJ ~- (Membeh) (Head of Department May 1979 ABSTRACT Observational...

Baer, Katherine Louise

1979-01-01T23:59:59.000Z

283

Hot Pot Field Observations  

SciTech Connect (OSTI)

Map of field observations including depressions, springs, evidence of former springs, travertine terraces and vegetation patterns. Map also contains interpretation of possible spring alignments.

Lane, Michael

2013-06-28T23:59:59.000Z

284

Hot Pot Field Observations  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

Map of field observations including depressions, springs, evidence of former springs, travertine terraces and vegetation patterns. Map also contains interpretation of possible spring alignments.

Lane, Michael

285

Dark energy models with variable equation of state parameter  

E-Print Network [OSTI]

The dark energy models with variable equation of state parameter $\\omega$ is investigated by using law of variation of Hubble's parameter that yields the constant value of deceleration parameter. The equation of state parameter $\\omega$ is found to be time dependent and its existing range for this model is consistent with the recent observations of SN Ia data, SN Ia data (with CMBR anisotropy) and galaxy clustering statistics. The physical significance of the dark energy models has also been discussed.

Anil Kumar Yadav; Farook Rahaman; Saibal Ray

2010-09-24T23:59:59.000Z

286

Variable ratio regenerative braking device  

DOE Patents [OSTI]

Disclosed is a regenerative braking device (10) for an automotive vehicle. The device includes an energy storage assembly (12) having a plurality of rubber rollers (26, 28) mounted for rotation between an input shaft (36) and an output shaft (42), clutches (38, 46) and brakes (40, 48) associated with each shaft, and a continuously variable transmission (22) connectable to a vehicle drivetrain and to the input and output shafts by the respective clutches. The rubber rollers are torsionally stressed to accumulate energy from the vehicle when the input shaft is clutched to the transmission while the brake on the output shaft is applied, and are torsionally relaxed to deliver energy to the vehicle when the output shaft is clutched to the transmission while the brake on the input shaft is applied. The transmission ratio is varied to control the rate of energy accumulation and delivery for a given rotational speed of the vehicle drivetrain.

Hoppie, Lyle O. (Birmingham, MI)

1981-12-15T23:59:59.000Z

287

Variable delivery, fixed displacement pump  

DOE Patents [OSTI]

A variable delivery, fixed displacement pump comprises a plurality of pistons reciprocated within corresponding cylinders in a cylinder block. The pistons are reciprocated by rotation of a fixed angle swash plate connected to the pistons. The pistons and cylinders cooperate to define a plurality of fluid compression chambers each have a delivery outlet. A vent port is provided from each fluid compression chamber to vent fluid therefrom during at least a portion of the reciprocal stroke of the piston. Each piston and cylinder combination cooperates to close the associated vent port during another portion of the reciprocal stroke so that fluid is then pumped through the associated delivery outlet. The delivery rate of the pump is varied by adjusting the axial position of the swash plate relative to the cylinder block, which varies the duration of the piston stroke during which the vent port is closed.

Sommars, Mark F. (Sparland, IL)

2001-01-01T23:59:59.000Z

288

Continuously variable focal length lens  

DOE Patents [OSTI]

A material preferably in crystal form having a low atomic number such as beryllium (Z=4) provides for the focusing of x-rays in a continuously variable manner. The material is provided with plural spaced curvilinear, optically matched slots and/or recesses through which an x-ray beam is directed. The focal length of the material may be decreased or increased by increasing or decreasing, respectively, the number of slots (or recesses) through which the x-ray beam is directed, while fine tuning of the focal length is accomplished by rotation of the material so as to change the path length of the x-ray beam through the aligned cylindrical slows. X-ray analysis of a fixed point in a solid material may be performed by scanning the energy of the x-ray beam while rotating the material to maintain the beam's focal point at a fixed point in the specimen undergoing analysis.

Adams, Bernhard W; Chollet, Matthieu C

2013-12-17T23:59:59.000Z

289

Variable residence time vortex combustor  

DOE Patents [OSTI]

A variable residence time vortex combustor including a primary combustion chamber for containing a combustion vortex, and a plurality of louvres peripherally disposed about the primary combustion chamber and longitudinally distributed along its primary axis. The louvres are inclined to impel air about the primary combustion chamber to cool its interior surfaces and to impel air inwardly to assist in driving the combustion vortex in a first rotational direction and to feed combustion in the primary combustion chamber. The vortex combustor also includes a second combustion chamber having a secondary zone and a narrowed waist region in the primary combustion chamber interconnecting the output of the primary combustion chamber with the secondary zone for passing only lower density particles and trapping higher density particles in the combustion vortex in the primary combustion chamber for substantial combustion.

Melconian, Jerry O. (76 Beaver Rd., Reading, MA 01867)

1987-01-01T23:59:59.000Z

290

Exact Maximum Likelihood estimator for the BL-GARCH model under elliptical distributed  

E-Print Network [OSTI]

Exact Maximum Likelihood estimator for the BL-GARCH model under elliptical distributed innovations, Brisbane QLD 4001, Australia Abstract We are interested in the parametric class of Bilinear GARCH (BL-GARCH examine, in this paper, the BL-GARCH model in a general setting under some non-normal distributions. We

Paris-Sud XI, Universit de

291

Benefits of the International Residential Code's Maximum Solar heat Gain Coefficient Requirement for Windows  

E-Print Network [OSTI]

Texas adopted in its residential building energy code a maximum 0.40 solar heat gain coefficient (SHGC) for fenestration (e.g., windows, glazed doors and skylights)-a critical driver of cooling energy use, comfort and peak demand. An analysis...

Stone, G. A.; DeVito, E. M.; Nease, N. H.

2002-01-01T23:59:59.000Z

292

Ocean Circulation During the Last Glacial Maximum Simulated by PMIP3 Climate Models  

E-Print Network [OSTI]

in the intensity of the Atlantic Overturning Circulation (distinguished by the local maximum at approximately 30 N %. In the plot corresponding to the World Ocean Circulation, an increase in the Deep Circulation, associated of the water masses as well as the impact on ocean carbon storage. References: [1] Godfrey J. S., Geophysics

Schmittner, Andreas

293

The chronology of the Last Glacial Maximum and deglacial events in central Argentine Patagonia  

E-Print Network [OSTI]

The chronology of the Last Glacial Maximum and deglacial events in central Argentine Patagonia and deglaciation in the Lago Pueyrredo´n valley of central Patagonia, 47.5 S, Argentina. The valley was a major and the onset of deglaciation occurred broadly synchronously throughout Patagonia. Deglaciation resulted

294

Single-machine scheduling with periodic and exible periodic maintenance to minimize maximum tardiness  

E-Print Network [OSTI]

periods often appear in industry due to a machine breakdown (stochastic) or preventive maintenance of machine unavailability. However, in some cases (e.g. preventive maintenance), the maintenance of a machineSingle-machine scheduling with periodic and exible periodic maintenance to minimize maximum

Paris-Sud XI, Université de

295

THE SECOND LAW OF THERMODYNAMICS AND THE GLOBAL CLIMATE SYSTEM: A REVIEW OF THE MAXIMUM  

E-Print Network [OSTI]

to absorption of solar radiation in the climate system is found to be irrelevant to the maximized prop- erties from hot to cold places, thereby producing the kinetic energy of the fluid itself. His generalTHE SECOND LAW OF THERMODYNAMICS AND THE GLOBAL CLIMATE SYSTEM: A REVIEW OF THE MAXIMUM ENTROPY

Lorenz, Ralph D.

296

Hydraulic limits on maximum plant transpiration and the emergence of the safetyefficiency trade-off  

E-Print Network [OSTI]

Hydraulic limits on maximum plant transpiration and the emergence of the safetyefficiency trade.12126 Key words: hydraulic limitation, safety efficiency trade-off, soilplantatmosphere model, trait hydraulics constrain ecosystem productivity by setting physical limits to water transport and hence carbon

Jackson, Robert B.

297

Performance of Photovoltaic Maximum Power Point Tracking Algorithms in the Presence of Noise  

E-Print Network [OSTI]

Performance of Photovoltaic Maximum Power Point Tracking Algorithms in the Presence of Noise tracking (MPPT) algorithms for photovoltaic systems, including how noise affects both tracking speed-performance photovoltaic sys- tems. An intelligent controller adjusts the voltage, current, or impedance seen by a solar

Odam, Kofi

298

Towards a frequency-dependent discrete maximum principle for the implicit Monte Carlo equations  

SciTech Connect (OSTI)

It has long been known that temperature solutions of the Implicit Monte Carlo (IMC) equations can exceed the external boundary temperatures, a so-called violation of the 'maximum principle.' Previous attempts at prescribing a maximum value of the time-step size {Delta}{sub t} that is sufficient to eliminate these violations have recommended a {Delta}{sub t} that is typically too small to be used in practice and that appeared to be much too conservative when compared to numerical solutions of the IMC equations for practical problems. In this paper, we derive a new estimator for the maximum time-step size that includes the spatial-grid size {Delta}{sub x}. This explicitly demonstrates that the effect of coarsening {Delta}{sub x} is to reduce the limitation on {Delta}{sub t}, which helps explain the overly conservative nature of the earlier, grid-independent results. We demonstrate that our new time-step restriction is a much more accurate means of predicting violations of the maximum principle. We discuss how the implications of the new, grid-dependent timestep restriction can impact IMC solution algorithms.

Wollaber, Allan B [Los Alamos National Laboratory; Larsen, Edward W [Los Alamos National Laboratory; Densmore, Jeffery D [Los Alamos National Laboratory

2010-12-15T23:59:59.000Z

299

Hydroelastic analysis of the floating plate optimized for maximum radiation damping  

E-Print Network [OSTI]

Hydroelastic analysis of the floating plate optimized for maximum radiation damping Christopher J t In previous work, the problem of optimizing the shape of a thin floating plate to maximize radiation damping, incompressible ocean of infinite extent. For simplicity, only rigid heave motions were considered and the damping

Damaren, Christopher J.

300

Maximum late Holocene extent of the western Greenland Ice Sheet during the late 20th century  

E-Print Network [OSTI]

the 20th century. This suggests a lagged ice-margin response to prior cooling, such as the Little Ice AgeMaximum late Holocene extent of the western Greenland Ice Sheet during the late 20th century Samuel Keywords: Greenland Ice Sheet Little Ice Age 10 Be exposure dating Ice-dammed lake Lake sediment core a b

Briner, Jason P.

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Maximum Likelihood Estimation of Mixture Densities for Binned and Truncated Multivariate  

E-Print Network [OSTI]

Maximum Likelihood Estimation of Mixture Densities for Binned and Truncated Multivariate Data in data analysis and machine learning. This paper addresses the problem of fitting mixture densities to multivariate binned and truncated data. The EM approach proposed by McLachlan and Jones (1988

Smyth, Padhraic

302

Design of wind farm layout for maximum wind energy capture Andrew Kusiak*, Zhe Song  

E-Print Network [OSTI]

Design of wind farm layout for maximum wind energy capture Andrew Kusiak*, Zhe Song Intelligent Accepted 24 August 2009 Available online 22 September 2009 Keywords: Wind farm Wind turbine Layout design Optimization Evolutionary algorithms Operations research a b s t r a c t Wind is one of the most promising

Kusiak, Andrew

303

Maximum Class Separability for Rough-Fuzzy C-Means Based Brain MR Image Segmentation  

E-Print Network [OSTI]

Maximum Class Separability for Rough-Fuzzy C-Means Based Brain MR Image Segmentation Pradipta Maji of brain MR images. The RFCM algorithm comprises a judicious integration of the of rough sets, fuzzy sets with vagueness and incompleteness in class definition of brain MR images, the membership function of fuzzy sets

Pal, Sankar Kumar

304

Maximum-entropy meshfree method for nonlinear static analysis of planar reinforced concrete structures  

E-Print Network [OSTI]

the nonlinear system of equations. Maximum-entropy basis functions are used to discretize the two displacement control method is implemented to solve the nonlinear system of equations and to obtain tools in the field of structural engineering, Yaw and co-workers [1] presented a blended FE and meshfree

Sukumar, N.

305

Maximum Utility Product Pricing Models and Algorithms Based on Reservation Prices  

E-Print Network [OSTI]

Maximum Utility Product Pricing Models and Algorithms Based on Reservation Prices R. Shioda L. Tun for pricing a product line with several customer segments under the assumption that customers' product choices utility model and formulate it as a mixed-integer programming problem, design heuristics and valid cuts

Tunçel, Levent

306

Self-Assembly for Maximum Yields Under Constraints Michael J. Fox and Jeff S. Shamma  

E-Print Network [OSTI]

Self-Assembly for Maximum Yields Under Constraints Michael J. Fox and Jeff S. Shamma Abstract-- We present an algorithm that, given any target tree, synthesizes reversible self-assembly rules that provide states that cannot be recovered from the unlabeled graph. I. INTRODUCTION Self-assembly is the phenomenon

Shamma, Jeff S.

307

Generalized Local Maximum Principles for Finite-Difference Operators Author(s): Achi Brandt  

E-Print Network [OSTI]

Generalized Local Maximum Principles for Finite-Difference Operators Author(s): Achi Brandt Source://www.jstor.org/action/showPublisher?publisherCode=ams. . Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission. JSTOR is a not-for-profit service that helps scholars

308

Energy Production, Frictional Dissipation, and Maximum Intensity of a Numerically Simulated Tropical Cyclone  

E-Print Network [OSTI]

0 Energy Production, Frictional Dissipation, and Maximum Intensity of a Numerically Simulated) viewed as a heat engine converts heat energy extracted from the ocean to kinetic energy of the TC, which is eventually dissipated due to surface friction. Since the energy production rate is a linear function while

Wang, Yuqing

309

Energy Production, Frictional Dissipation, and Maximum Intensity of a Numerically Simulated Tropical Cyclone*  

E-Print Network [OSTI]

Energy Production, Frictional Dissipation, and Maximum Intensity of a Numerically Simulated as a heat engine converts heat energy extracted from the ocean into the kinetic energy of the TC, which is eventually dissipated due to surface friction. Since the energy production rate is a linear function while

Wang, Yuqing

310

NOAA Technical Memorandum NWS HYDRO 39 PROBABLE MAXIMUM PRECIPITATION FOR THE UPPER  

E-Print Network [OSTI]

NOAA Technical Memorandum NWS HYDRO 39 PROBABLE MAXIMUM PRECIPITATION FOR THE UPPER DEERFIELD RIVER The Office of Hydrology (HYDRO) of the National Weather Service (NWS) develops procedures for making river agencies, and conducts pertinent research and development. NOAA Technical Memorandums in the NWS HYDRO

311

Integrating ecophysiology and plankton dynamics into projected changes in maximum fisheries catch potential under climate  

E-Print Network [OSTI]

). In addition, average surface water pH of the ocean has dropped by 0.1 units since pre- industrial timesIntegrating ecophysiology and plankton dynamics into projected changes in maximum fisheries catch 7TJ, UK 2 Centre for Environment, Fisheries and Aquaculture Science, Pakefield Road, Lowestoft

Pauly, Daniel

312

Blind Equalization via Approximate Maximum Likelihood Source Seungjin CHOI x1 and Andrzej CICHOCKI y  

E-Print Network [OSTI]

Blind Equalization via Approximate Maximum Likelihood Source Separation Seungjin CHOI x1, RIKEN 2-1 Hirosawa, Wako-shi Saitama 351-0198, JAPAN Abstract Blind equalization of single input multiple output (SIMO) FIR channels can be refor- mulated as the problem of blind source separation

Choi, Seungjin

313

Power and Sample Size Determination for a Stepwise Test Procedure for Finding the Maximum Safe Dose  

E-Print Network [OSTI]

Power and Sample Size Determination for a Stepwise Test Procedure for Finding the Maximum Safe Dose This paper addresses the problem of power and sample size calculation for a stepwise multiple test procedure of a compound. A general expression for the power of this procedure is derived. It is used to find the minimum

Tamhane, Ajit C.

314

Optimization of stomatal conductance for maximum carbon gain under dynamic soil moisture  

E-Print Network [OSTI]

Optimization of stomatal conductance for maximum carbon gain under dynamic soil moisture Stefano Accepted 26 September 2013 Available online 9 October 2013 Keywords: Optimization Photosynthesis Soil moisture Stomatal conductance Transpiration a b s t r a c t Optimization theories explain a variety

Katul, Gabriel

315

A Distributed Approach to Maximum Power Point Tracking for Photovoltaic Sub-Module Differential  

E-Print Network [OSTI]

of the proposed distributed algorithm. I. INTRODUCTION IN photovoltaic (PV) energy systems, PV modules are often of the system, small size and low power ratings of the power electronics circuit components. Due1 A Distributed Approach to Maximum Power Point Tracking for Photovoltaic Sub-Module Differential

Liberzon, Daniel

316

Uncorking the bottle: What triggered the Paleocene/Eocene thermal maximum methane release?  

E-Print Network [OSTI]

Uncorking the bottle: What triggered the Paleocene/Eocene thermal maximum methane release? Miriam E realms that has been attributed to a massive methane (CH4) release from marine gas hydrate reservoirs. Previously proposed mechanisms for this methane release rely on a change in deepwater source region

317

Electrical Estimation of Conditional Probability for Maximum-likelihood Based PMD Mitigation  

E-Print Network [OSTI]

Xi, Tulay Adali, and John Zweck Department of Computer Science and Electrical Engineering UniversityElectrical Estimation of Conditional Probability for Maximum-likelihood Based PMD Mitigation Wenze probability density functions in the presence of both all-order PMD and ASE noise are estimated electronically

Zweck, John

318

Hydrogen Molecules inside Fullerene C70: Quantum Dynamics, Energetics, Maximum Occupancy, And Comparison with C60  

E-Print Network [OSTI]

Hydrogen Molecules inside Fullerene C70: Quantum Dynamics, Energetics, Maximum Occupancy of Chemistry, New York UniVersity, New York, New York 10003, Department of Chemistry, Brown UniVersity, ProVidence, Rhode Island 02912, and Department of Chemistry, Columbia UniVersity, New York, New York 10027 Received

Turro, Nicholas J.

319

Maximum Power Point Tracking Control for Photovoltaic System Using Adaptive Neuro-Fuzzy  

E-Print Network [OSTI]

conventional controller like Adaptive Neuro-Fuzzy "ANFIS" and fuzzy logic controller is proposed and simulated power point tracking (MPPT) technique will be used. Fuzzy logic control "FLC" and adaptive neuro-fuzzyMaximum Power Point Tracking Control for Photovoltaic System Using Adaptive Neuro- Fuzzy "ANFIS

Paris-Sud XI, Université de

320

Magnetofossil spike during the Paleocene-Eocene thermal maximum: Ferromagnetic resonance, rock magnetic, and electron microscopy  

E-Print Network [OSTI]

Magnetofossil spike during the Paleocene-Eocene thermal maximum: Ferromagnetic resonance, rock,2 Timothy D. Raub,3,4 Dirk Schumann,5 Hojatollah Vali,5 Alexei V. Smirnov,3,6 and Joseph L. Kirschvink1 controversial hypothesis that a cometary impact triggered the PETM. Here we present ferromagnetic resonance (FMR

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Extraction of Spectral Functions from Dyson-Schwinger Studies via the Maximum Entropy Method  

E-Print Network [OSTI]

It is shown how to apply the Maximum Entropy Method (MEM) to numerical Dyson-Schwinger studies for the extraction of spectral functions of correlators from their corresponding Euclidean propagators. Differences to the application in lattice QCD are emphasized and, as an example, the spectral functions of massless quarks in cold and dense matter are presented.

Dominik Nickel

2006-07-20T23:59:59.000Z

322

Parameters estimation for spatio-temporal maximum entropy distributions: application to neural spike trains  

E-Print Network [OSTI]

We propose a numerical method to learn Maximum Entropy (MaxEnt) distributions with spatio-temporal constraints from experimental spike trains. This is an extension of two papers [10] and [4] who proposed the estimation of parameters where only spatial constraints were taken into account. The extension we propose allows to properly handle memory effects in spike statistics, for large sized neural networks.

Nasser, Hassan

2014-01-01T23:59:59.000Z

323

Beyond Boltzmann-Gibbs statistics: Maximum entropy hyperensembles out of equilibrium Gavin E. Crooks*  

E-Print Network [OSTI]

Beyond Boltzmann-Gibbs statistics: Maximum entropy hyperensembles out of equilibrium Gavin E at equilibrium? Here, we argue the most appropriate additional parameter is the nonequilibrium entropy of ways that the same system can be out of equilibrium. That the equilibrium entropy is maximized given

324

Extraction of spectral functions from Dyson-Schwinger studies via the maximum entropy method  

SciTech Connect (OSTI)

It is shown how to apply the Maximum Entropy Method (MEM) to numerical Dyson-Schwinger studies for the extraction of spectral functions of correlators from their corresponding Euclidean propagators. Differences to the application in lattice QCD are emphasized and, as an example, the spectral functions of massless quarks in cold and dense matter are presented.

Nickel, Dominik [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany)]. E-mail: dominik.nickel@physik.tu-darmstadt.de

2007-08-15T23:59:59.000Z

325

Lattice Field Theory with the Sign Problem and the Maximum Entropy Method  

E-Print Network [OSTI]

Although numerical simulation in lattice field theory is one of the most effective tools to study non-perturbative properties of field theories, it faces serious obstacles coming from the sign problem in some theories such as finite density QCD and lattice field theory with the $\\theta$ term. We reconsider this problem from the point of view of the maximum entropy method.

Masahiro Imachi; Yasuhiko Shinno; Hiroshi Yoneyama

2007-02-09T23:59:59.000Z

326

A PROXIMITY CONTROL ALGORITHM TO MINIMIZE NONSMOOTH AND NONCONVEX SEMI-INFINITE MAXIMUM  

E-Print Network [OSTI]

in the context of eigen- value optimization, and [8] gives an overview of the history. The bases for the presentA PROXIMITY CONTROL ALGORITHM TO MINIMIZE NONSMOOTH AND NONCONVEX SEMI-INFINITE MAXIMUM EIGENVALUE function, semi-infinite problem, H-norm. 1. Introduction. Proximity control for bundle methods has been

Noll, Dominikus

327

A PROXIMITY CONTROL ALGORITHM TO MINIMIZE NONSMOOTH AND NONCONVEX SEMI-INFINITE MAXIMUM  

E-Print Network [OSTI]

in the context of eigen- value optimization, and [9] gives an overview of the history. The bases for the presentA PROXIMITY CONTROL ALGORITHM TO MINIMIZE NONSMOOTH AND NONCONVEX SEMI-INFINITE MAXIMUM EIGENVALUE function, semi-infinite problem, H-norm. 1. Introduction. Proximity control for bundle methods has been

Noll, Dominikus

328

SALTSTONE DISPOSAL FACILITY: DETERMINATION OF THE PROBABLE MAXIMUM WATER TABLE ELEVATION  

SciTech Connect (OSTI)

A coverage depicting the configuration of the probable maximum water table elevation in the vicinity of the Saltstone Disposal Facility (SDF) was developed to support the Saltstone program. This coverage is needed to support the construction of saltstone vaults to assure that they remain above the maximum elevation of the water table during the Performance Assessment (PA) period of compliance. A previous investigation to calculate the historical high water table beneath the SDF (Cook, 1983) was built upon to incorporate new data that has since become available to refine that estimate and develop a coverage that could be extended to the perennial streams adjacent to the SDF. This investigation incorporated the method used in the Cook, 1983 report to develop an estimate of the probable maximum water table for a group of wells that either existed at one time at or near the SDF or which currently exist. Estimates of the probable maximum water table at these wells were used to construct 2D contour lines depicting this surface beneath the SDF and extend them to the nearby hydrologic boundaries at the perennial streams adjacent to the SDF. Although certain measures were implemented to assure that the contour lines depict a surface above which the water table will not rise, the exact elevation of this surface cannot be known with complete certainty. It is therefore recommended that the construction of saltstone vaults incorporate a vertical buffer of at least 5-feet between the base of the vaults and the depicted probable maximum water table elevation. This should provide assurance that the water table under the wet extreme climatic condition will never rise to intercept the base of a vault.

Hiergesell, R

2005-04-01T23:59:59.000Z

329

Using the Maximum X-ray Flux Ratio and X-ray Background to Predict Solar Flare Class  

E-Print Network [OSTI]

We present the discovery of a relationship between the maximum ratio of the flare flux (namely, 0.5-4 Ang to the 1-8 Ang flux) and non-flare background (namely, the 1-8 Ang background flux), which clearly separates flares into classes by peak flux level. We established this relationship based on an analysis of the Geostationary Operational Environmental Satellites (GOES) X-ray observations of ~ 50,000 X, M, C, and B flares derived from the NOAA/SWPC flares catalog. Employing a combination of machine learning techniques (K-nearest neighbors and nearest-centroid algorithms) we show a separation of the observed parameters for the different peak flaring energies. This analysis is validated by successfully predicting the flare classes for 100% of the X-class flares, 76% of the M-class flares, 80% of the C-class flares and 81% of the B-class flares for solar cycle 24, based on the training of the parametric extracts for solar flares in cycles 22-23.

Winter, Lisa M

2015-01-01T23:59:59.000Z

330

HCCI in a Variable Compression Ratio Engine: Effects of Engine...  

Broader source: Energy.gov (indexed) [DOE]

Fuels Practical Full Time HCCI Operation Will Require Specific HCCI Fuel Low Octane gasoline Experimental Variables Experimental Variables Engine Variables Intake Manifold...

331

Examining Uncertainty in Demand Response Baseline Models and Variability in Automated Response to Dynamic Pricing  

SciTech Connect (OSTI)

Controlling electric loads to deliver power system services presents a number of interesting challenges. For example, changes in electricity consumption of Commercial and Industrial (C&I) facilities are usually estimated using counterfactual baseline models, and model uncertainty makes it difficult to precisely quantify control responsiveness. Moreover, C&I facilities exhibit variability in their response. This paper seeks to understand baseline model error and demand-side variability in responses to open-loop control signals (i.e. dynamic prices). Using a regression-based baseline model, we define several Demand Response (DR) parameters, which characterize changes in electricity use on DR days, and then present a method for computing the error associated with DR parameter estimates. In addition to analyzing the magnitude of DR parameter error, we develop a metric to determine how much observed DR parameter variability is attributable to real event-to-event variability versus simply baseline model error. Using data from 38 C&I facilities that participated in an automated DR program in California, we find that DR parameter errors are large. For most facilities, observed DR parameter variability is likely explained by baseline model error, not real DR parameter variability; however, a number of facilities exhibit real DR parameter variability. In some cases, the aggregate population of C&I facilities exhibits real DR parameter variability, resulting in implications for the system operator with respect to both resource planning and system stability.

Mathieu, Johanna L.; Callaway, Duncan S.; Kiliccote, Sila

2011-08-15T23:59:59.000Z

332

Variability in Automated Responses of Commercial Buildings and Industrial Facilities to Dynamic Electricity Prices  

SciTech Connect (OSTI)

Changes in the electricity consumption of commercial buildings and industrial facilities (C&I facilities) during Demand Response (DR) events are usually estimated using counterfactual baseline models. Model error makes it difficult to precisely quantify these changes in consumption and understand if C&I facilities exhibit event-to-event variability in their response to DR signals. This paper seeks to understand baseline model error and DR variability in C&I facilities facing dynamic electricity prices. Using a regression-based baseline model, we present a method to compute the error associated with estimates of several DR parameters. We also develop a metric to determine how much observed DR variability results from baseline model error rather than real variability in response. We analyze 38 C&I facilities participating in an automated DR program and find that DR parameter errors are large. Though some facilities exhibit real DR variability, most observed variability results from baseline model error. Therefore, facilities with variable DR parameters may actually respond consistently from event to event. Consequently, in DR programs in which repeatability is valued, individual buildings may be performing better than previously thought. In some cases, however, aggregations of C&I facilities exhibit real DR variability, which could create challenges for power system operation.

Mathieu, Johanna L.; Callaway, Duncan S.; Kiliccote, Sila

2011-08-16T23:59:59.000Z

333

Eccentric crank variable compression ratio mechanism  

DOE Patents [OSTI]

A variable compression ratio mechanism for an internal combustion engine that has an engine block and a crankshaft is disclosed. The variable compression ratio mechanism has a plurality of eccentric disks configured to support the crankshaft. Each of the plurality of eccentric disks has at least one cylindrical portion annularly surrounded by the engine block. The variable compression ratio mechanism also has at least one actuator configured to rotate the plurality of eccentric disks.

Lawrence, Keith Edward (Kobe, JP); Moser, William Elliott (Peoria, IL); Roozenboom, Stephan Donald (Washington, IL); Knox, Kevin Jay (Peoria, IL)

2008-05-13T23:59:59.000Z

334

On the minimum and maximum mass of neutron stars and the delayed collapse  

E-Print Network [OSTI]

The minimum and maximum mass of protoneutron stars and neutron stars are investigated. The hot dense matter is described by relativistic (including hyperons) and non-relativistic equations of state. We show that the minimum mass ($\\sim$ 0.88 - 1.28 $M_{\\sun}$) of a neutron star is determined by the earliest stage of its evolution and is nearly unaffected by the presence of hyperons. The maximum mass of a neutron star is limited by the protoneutron star or hot neutron star stage. Further we find that the delayed collapse of a neutron star into a black hole during deleptonization is not only possible for equations of state with softening components, as for instance, hyperons, meson condensates etc., but also for neutron stars with a pure nucleonic-leptonic equation of state.

Strobel, K; Strobel, Klaus; Weigel, Manfred K.

2001-01-01T23:59:59.000Z

335

On the minimum and maximum mass of neutron stars and the delayed collapse  

E-Print Network [OSTI]

The minimum and maximum mass of protoneutron stars and neutron stars are investigated. The hot dense matter is described by relativistic (including hyperons) and non-relativistic equations of state. We show that the minimum mass ($\\sim$ 0.88 - 1.28 $M_{\\sun}$) of a neutron star is determined by the earliest stage of its evolution and is nearly unaffected by the presence of hyperons. The maximum mass of a neutron star is limited by the protoneutron star or hot neutron star stage. Further we find that the delayed collapse of a neutron star into a black hole during deleptonization is not only possible for equations of state with softening components, as for instance, hyperons, meson condensates etc., but also for neutron stars with a pure nucleonic-leptonic equation of state.

Klaus Strobel; Manfred K. Weigel

2000-12-14T23:59:59.000Z

336

A comparison of maximum likelihood and other estimators of eigenvalues from several correlated Monte Carlo samples  

SciTech Connect (OSTI)

The maximum likelihood method for the multivariate normal distribution is applied to the case of several individual eigenvalues. Correlated Monte Carlo estimates of the eigenvalue are assumed to follow this prescription and aspects of the assumption are examined. Monte Carlo cell calculations using the SAM-CE and VIM codes for the TRX-1 and TRX-2 benchmark reactors, and SAM-CE full core results are analyzed with this method. Variance reductions of a few percent to a factor of 2 are obtained from maximum likelihood estimation as compared with the simple average and the minimum variance individual eigenvalue. The numerical results verify that the use of sample variances and correlation coefficients in place of the corresponding population statistics still leads to nearly minimum variance estimation for a sufficient number of histories and aggregates.

Beer, M.

1980-12-01T23:59:59.000Z

337

An Ad-Hoc Method for Obtaining chi**2 Values from Unbinned Maximum Likelihood Fits  

E-Print Network [OSTI]

A common goal in an experimental physics analysis is to extract information from a reaction with multi-dimensional kinematics. The preferred method for such a task is typically the unbinned maximum likelihood method. In fits using this method, the likelihood is a goodness-of-fit quantity in that it effectively discriminates between available hypotheses; however, it does not provide any information as to how well the best hypothesis describes the data. In this paper, we present an {\\em ad-hoc} procedure for obtaining chi**2/n.d.f. values from unbinned maximum likelihood fits. This method does not require binning the data, making it very applicable to multi-dimensional problems.

M. Williams; C. A. Meyer

2008-06-30T23:59:59.000Z

338

Maximum-Entropy Meshfree Method for Compressible and Near-Incompressible Elasticity  

SciTech Connect (OSTI)

Numerical integration errors and volumetric locking in the near-incompressible limit are two outstanding issues in Galerkin-based meshfree computations. In this paper, we present a modified Gaussian integration scheme on background cells for meshfree methods that alleviates errors in numerical integration and ensures patch test satisfaction to machine precision. Secondly, a locking-free small-strain elasticity formulation for meshfree methods is proposed, which draws on developments in assumed strain methods and nodal integration techniques. In this study, maximum-entropy basis functions are used; however, the generality of our approach permits the use of any meshfree approximation. Various benchmark problems in two-dimensional compressible and near-incompressible small strain elasticity are presented to demonstrate the accuracy and optimal convergence in the energy norm of the maximum-entropy meshfree formulation.

Ortiz, A; Puso, M A; Sukumar, N

2009-09-04T23:59:59.000Z

339

Variable-Period Undulators For Synchrotron Radiation  

DOE Patents [OSTI]

A new and improved undulator design is provided that enables a variable period length for the production of synchrotron radiation from both medium-energy and high-energy storage rings. The variable period length is achieved using a staggered array of pole pieces made up of high permeability material, permanent magnet material, or an electromagnetic structure. The pole pieces are separated by a variable width space. The sum of the variable width space and the pole width would therefore define the period of the undulator. Features and advantages of the invention include broad photon energy tunability, constant power operation and constant brilliance operation.

Shenoy, Gopal (Naperville, IL); Lewellen, John (Plainfield, IL); Shu, Deming (Darien, IL); Vinokurov, Nikolai (Novosibirsk, RU)

2005-02-22T23:59:59.000Z

340

Variable-Period Undulators for Synchrotron Radiation  

SciTech Connect (OSTI)

A new and improved undulator design is provided that enables a variable period length for the production of synchrotron radiation from both medium-energy and high energy storage rings. The variable period length is achieved using a staggered array of pole pieces made up of high permeability material, permanent magnet material, or an electromagnetic structure. The pole pieces are separated by a variable width space. The sum of the variable width space and the pole width would therefore define the period of the undulator. Features and advantages of the invention include broad photon energy tunability, constant power operation and constant brilliance operation.

Shenoy, Gopal; Lewellen, John; Shu, Deming; Vinokurov, Nikolai

2005-02-22T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Multivector Functions of a Real Variable  

E-Print Network [OSTI]

This paper is an introduction to the theory of multivector functions of a real variable. The notions of limit, continuity and derivative for these objects are given. The theory of multivector functions of a real variable, even being similar to the usual theory of vector functions of a real variable, has some subtle issues which make its presentation worhtwhile.We refer in particular to the derivative rules involving exterior and Clifford products, and also to the rule for derivation of a composition of an ordinary scalar function with a multivector function of a real variable.

A. M. Moya; V. V. Fernndez; W. A. Rodrigues Jr

2002-12-17T23:59:59.000Z

342

Hybrid Bayesian Networks with Linear Deterministic Variables  

E-Print Network [OSTI]

Conference (UAI-05), 2005, AUAI Press, Arlington, VA. 136 Y X Z Figure 2: A Bayesian Network Representation of the Mixed Distribution for X. this example, Y is a discrete variable with state space ? Y = {1,2,3}, Z is a real-valued variable, and X is a... conditionally deterministic variable whose condi- tional distribution is described as follows: X |{y,z} = y if y =1,2 and X |{y,z} = z if y =3. Potentials of the type described above are used in this paper to represent distributions of variables in hy- brid...

Cobb, Barry R.; Shenoy, Prakash P.

2005-07-01T23:59:59.000Z

343

Computation of the maximum loadability of a power system using nonlinear optimization  

E-Print Network [OSTI]

Between Generator and Load. . . . . . . . . 34 E. Flowchart for Optimization Program F. Tutorial Example G. Conclusion. . 35 36 44 V SIMULATION RESULTS. 45 A. Introduction. B. Results of Simulation for Maximum Loadability of the Total System. I... of this work starting from the basics. Chapter III will cover concepts of power flow and loadability along with tutorial example. The literature survey over this topic and previous work as well as problem statement and solution method will be covered...

Khabirov, Abdufarrukh

2001-01-01T23:59:59.000Z

344

An Analysis of Maximum Residential Energy Efficiency in Hot and Humid Climates  

E-Print Network [OSTI]

the high efficiency instantaneous water heater with electronic ignition. The largest equipment energy savings (20%) was achieved from the horizontal-axis clothes washer. Compact fluorescent lamps (CFLs) saved 75% lighting energy use. Among all...AN ANALYSIS OF MAXIMUM RESIDENTIAL ENERGY EFFICIENCY IN HOT AND HUMID CLIMATES Mini Malhotra Graduate Research Assistant Jeff Haberl, Ph.D., P.E. Professor/Associate Director Energy Systems Laboratory, Texas A&M University College...

Malhotra, M.; Haberl, J. S.

2006-01-01T23:59:59.000Z

345

A maximum entropy theorem with applications to the measurement of biodiversity  

E-Print Network [OSTI]

This is a preliminary article stating and proving a new maximum entropy theorem. The entropies that we consider can be used as measures of biodiversity. In that context, the question is: for a given collection of species, which frequency distribution(s) maximize the diversity? The theorem provides the answer. The chief surprise is that although we are dealing not just with a single entropy, but a one-parameter family of entropies, there is a single distribution maximizing all of them simultaneously.

Leinster, Tom

2009-01-01T23:59:59.000Z

346

Hydrodynamic equations for electrons in graphene obtained from the maximum entropy principle  

SciTech Connect (OSTI)

The maximum entropy principle is applied to the formal derivation of isothermal, Euler-like equations for semiclassical fermions (electrons and holes) in graphene. After proving general mathematical properties of the equations so obtained, their asymptotic form corresponding to significant physical regimes is investigated. In particular, the diffusive regime, the Maxwell-Boltzmann regime (high temperature), the collimation regime and the degenerate gas limit (vanishing temperature) are considered.

Barletti, Luigi, E-mail: luigi.barletti@unifi.it [Dipartimento di Matematica e Informatica Ulisse Dini, Universit degli Studi di Firenze, Viale Morgagni 67/A, 50134 Firenze (Italy)

2014-08-15T23:59:59.000Z

347

REMARKS ON THE MAXIMUM ENTROPY METHOD APPLIED TO FINITE TEMPERATURE LATTICE QCD.  

SciTech Connect (OSTI)

We make remarks on the Maximum Entropy Method (MEM) for studies of the spectral function of hadronic correlators in finite temperature lattice QCD. We discuss the virtues and subtlety of MEM in the cases that one does not have enough number of data points such as at finite temperature. Taking these points into account, we suggest several tests which one should examine to keep the reliability for the results, and also apply them using mock and lattice QCD data.

UMEDA, T.; MATSUFURU, H.

2005-07-25T23:59:59.000Z

348

Towards the application of the Maximum Entropy Method to finite temperature Upsilon Spectroscopy  

E-Print Network [OSTI]

According to the Narnhofer Thirring Theorem interacting systems at finite temperature cannot be described by particles with a sharp dispersion law. It is therefore mandatory to develop new methods to extract particle masses at finite temperature. The Maximum Entropy method offers a path to obtain the spectral function of a particle correlation function directly. We have implemented the method and tested it with zero temperature Upsilon correlation functions obtained from an NRQCD simulation. Results for different smearing functions are discussed.

M. Oevers; C. Davies; J. Shigemitsu

2000-09-22T23:59:59.000Z

349

Maximum entropy deconvolution of resonant inelastic x-ray scattering spectra  

E-Print Network [OSTI]

Resonant inelastic x-ray scattering (RIXS) has become a powerful tool in the study of the electronic structure of condensed matter. Although the linewidths of many RIXS features are narrow, the experimental broadening can often hamper the identification of spectral features. Here, we show that the Maximum Entropy technique can successfully be applied in the deconvolution of RIXS spectra, improving the interpretation of the loss features without a severe increase in the noise ratio.

J. Laverock; A. R. H. Preston; D. Newby Jr; K. E. Smith; S. B. Dugdale

2012-02-10T23:59:59.000Z

350

Remarks on the Maximum Entropy Method applied to finite temperature lattice QCD  

E-Print Network [OSTI]

We make remarks on the Maximum Entropy Method (MEM) for studies of the spectral function of hadronic correlators in finite temperature lattice QCD. We discuss the virtues and subtlety of MEM in the cases that one does not have enough number of data points such as at finite temperature. Taking these points into account, we suggest several tests which one should examine to keep the reliability for the results, and also apply them using mock and lattice QCD data.

Takashi Umeda; Hideo Matsufuru

2005-10-05T23:59:59.000Z

351

Maximum Neutral Buoyancy Depth of Juvenile Chinook Salmon: Implications for Survival during Hydroturbine Passage  

SciTech Connect (OSTI)

This study investigated the maximum depth at which juvenile Chinook salmon Oncorhynchus tshawytscha can acclimate by attaining neutral buoyancy. Depth of neutral buoyancy is dependent upon the volume of gas within the swim bladder, which greatly influences the occurrence of injuries to fish passing through hydroturbines. We used two methods to obtain maximum swim bladder volumes that were transformed into depth estimations - the increased excess mass test (IEMT) and the swim bladder rupture test (SBRT). In the IEMT, weights were surgically added to the fishes exterior, requiring the fish to increase swim bladder volume in order to remain neutrally buoyant. SBRT entailed removing and artificially increasing swim bladder volume through decompression. From these tests, we estimate the maximum acclimation depth for juvenile Chinook salmon is a median of 6.7m (range = 4.6-11.6 m). These findings have important implications to survival estimates, studies using tags, hydropower operations, and survival of juvenile salmon that pass through large Kaplan turbines typical of those found within the Columbia and Snake River hydropower system.

Pflugrath, Brett D.; Brown, Richard S.; Carlson, Thomas J.

2012-03-01T23:59:59.000Z

352

Nonparametric Density Estimation for Stochastic Optimization with an Observable State Variable  

E-Print Network [OSTI]

-ahead wind commitment problem." A wind farm manager must pledge how much energy she will provide to a utility objective: the last 24 hours of wind and market prices, time of day and time of year all contain information problem and the hour ahead wind commit- ment problem. Our results show Dirichlet process weights can offer

Powell, Warren B.

353

Observed Variability of Ocean Wave Stokes Drift, and the Eulerian Response to Passing Groups  

E-Print Network [OSTI]

­current interactions are also considered important in generating and maintaining Langmuir circulation (LC), a prominent 2005, in final form 13 September 2005) ABSTRACT Waves and currents interact via exchanges of mass with current theory. 1. Introduction Surface waves are of central importance in general to air­sea interactions

Smith, Jerome A.

354

Mexican drought: an observational modeling and tree ring study of variability and climate change  

E-Print Network [OSTI]

by the state of the tropical Pacific Ocean with the Atlantical. (2005b). 1. POGA (Pacific Ocean-Global Atmosphere): Inoutside of the tropical Pacific Ocean that computes SST

2009-01-01T23:59:59.000Z

355

Mexican drought: an observational modeling and tree ring study of variability and climate change  

E-Print Network [OSTI]

of decentralization: Water reform and social implica- tionsWhen the rivers run dry: Water-the defining crisis of thefaces a future of declining water resources that will have

2009-01-01T23:59:59.000Z

356

On the Variability Coherence Observed in Black Hole Candidates at Different XRay Energies  

E-Print Network [OSTI]

a powerful mathematical method to estimate the coherence function (Bendat & Piersol 1986), they demonstrated thermal waves on an accretion disk (Manmoto et al. 1996), at 1 Department of Astronomy & Astrophysics, G¨oteborg University and Chalmers University of Technology, S­412 96 G¨oteborg, Sweden 2 Nordita, Copenhagen, Denmark 3

Wiita, Paul J.

357

SST subseasonal variability in the central Benguela upwelling system as inferred from satellite observations (19992009)  

E-Print Network [OSTI]

associated with the eastern flank of the semipermanent South Atlantic Anti- cyclone (SAA). Through Ekman of distinct physical and biological features, the Benguela system can be separated into three zones charac

Boyer, Edmond

358

Observational study on variability between biobanks in the estimation of DNA concentration  

E-Print Network [OSTI]

, University of Bristol, Bristol, UK, 10Estonian Genome Project, University of Tartu, Tartu, Estonia, 11Karolinska Institutet BioBank, Karolinska Institute, Stockholm, Sweden, 12National Public Health Institute, Biomedicum Helsinki, Helsinki, Finland and 13...

Brown, Jay; Donev, Alexander N; Aslanidis, Charalampos; Bracegirdle, Pippa; Dixon, Katherine P; Foedinger, Manuela; Gwilliam, Rhian; Hardy, Matthew; Illig, Thomas; Ke, Xiayi; Krinka, Dagni; Lagerberg, Camilla; Laiho, Paivi; Lewis, David H; McArdle, Wendy; Jones, Richard W; Patton, Simon; Ring, Susan M; Schmitz, Gerd; Stevens, Helen; Tybring, Gunnel; Wichmann, H Erich; Ollier, William E R; Yuille, Martin A

2009-10-13T23:59:59.000Z

359

Mexican drought: an observational modeling and tree ring study of variability and climate change  

E-Print Network [OSTI]

changes in Mexican agriculture over the last decade and a half are the combined result of severe climate-

2009-01-01T23:59:59.000Z

360

Experimental observations of deformation caused by mineral dissolution in variable-aperture fractures  

E-Print Network [OSTI]

are further influenced by stresses in the host rock. To quantitatively explore these coupled processes, we-water reactions. For example, subsurface CO2 sequestration in depleted oil and gas reservoirs or deep saline 1 August 2008. [1] Problems such as CO2 sequestration, petroleum production and nuclear waste

Detwiler, Russell

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

On the observed variability of the crosspolar cap potential W. A. Bristow,1  

E-Print Network [OSTI]

series of the IMF and solar wind. In addition, the data were examined statistically to obtain a best fit. Introduction [2] The cross­polar cap potential (PCP) parameterizes the degree to which solar wind energy) and solar wind velocity is presented. The potential estimates were examined as time series along with time

Shepherd, Simon

362

Observational constraints on models of the Universe with time variable Gravitational and Cosmological constants along MOG  

E-Print Network [OSTI]

The subject of this paper is to investigate the weak regime covariant scalar-tensor-vector gravity (STVG) theory, known as the MOdified gravity (MOG) theory of gravity. First, we show that the MOG in the absence of scalar fields is converted into $\\Lambda(t),G(t)$ models. Time evolution of the cosmological parameters for a family of viable models have been investigated. Numerical results with the cosmological data have been adjusted. We've introduced a model for dark energy (DE) density and cosmological constant which involves first order derivatives of Hubble parameter. To extend this model, correction terms including the gravitational constant are added. In our scenario, the cosmological constant is a function of time. To complete the model,interaction terms between dark energy and dark matter (DM) manually entered in phenomenological form. Instead of using the dust model for DM, we have proposed DM equivalent to a barotropic fluid. Time evolution of DM is a function of other cosmological parameters. Using sophisticated algorithms, the behavior of various quantities including the densities, Hubble parameter, etc. have been investigated graphically. The statefinder parameters have been used for the classification of DE models. Consistency of the numerical results with experimental data of $SneIa+BAO+CMB$ are studied by numerical analysis with high accuracy.

M. Khurshudyan; N. S. Mazhari; D. Momeni; R. Myrzakulov; M. Raza

2014-06-24T23:59:59.000Z

363

Observed 20th century desert dust variability: impact on climate and biogeochemistry  

E-Print Network [OSTI]

2010 in southern South America? , Geophys. Res. Lett. , 35,where in southern South America? , Geophys. Res. Lett. ,and desertification in South America, P. Natl. Acad. Sci. ,

2010-01-01T23:59:59.000Z

364

Mexican drought: an observational modeling and tree ring study of variability and climate change  

E-Print Network [OSTI]

America and northern South America. (In the annual mean theAmerica and northern South America. This pattern appearsMxico and northern South America, a pattern that is again

2009-01-01T23:59:59.000Z

365

Multiple linear regression: fixed and multinormal data with missing observations among the independent variables  

E-Print Network [OSTI]

) b 23 + W ( 3)b E (W'(x3) El b2 + W" (x3 E) b" ) 3 " ' "3 23 E (W (x ) + W (x ))B2 x3 '23 (3. 21) since W'(x ) + W" (x ) = l. 3 3 It should also be noted that if any group j (except 0) is not large enough to provide regression estimates... of The General Solution or that found in the previous section) from each of the t groups. Let b represent the estimate of B from the t-th group. Then an i estimate of the variance of b is found by the equation k Var(b)- E ( b -b ) /k 1 t i i k k . E t~l (3...

Johnston, Walter Edward

1965-01-01T23:59:59.000Z

366

Climate Extremes in the Southeast United States: Observed Variability, Spatial Classification, and Related Planning.  

E-Print Network [OSTI]

??Spatial and temporal trends in temperature and precipitation extremes were investigated for the Southeast United States for the period 1948 to 2012 using 27 extreme (more)

Powell, Emily J.

2014-01-01T23:59:59.000Z

367

Observing Massive Galaxy Formation  

E-Print Network [OSTI]

A major goal of contemporary astrophysics is understanding the origin of the most massive galaxies in the universe, particularly nearby ellipticals and spirals. Theoretical models of galaxy formation have existed for many decades, although low and high redshift observations are only beginning to put constraints on different ideas. We briefly describe these observations and how they are revealing the methods by which galaxies form by contrasting and comparing fiducial rapid collapse and hierarchical formation model predictions. The available data show that cluster ellipticals must have rapidly formed at z > 2, and that up to 50% of all massive galaxies at z ~ 2.5 are involved in major mergers. While the former is consistent with the monolithic collapse picture, we argue that hierarchal formation is the only model that can reproduce all the available observations.

Christopher J. Conselice

2002-12-20T23:59:59.000Z

368

Air Observe System  

E-Print Network [OSTI]

This manuscript contains a description and basic principles for observing inaccessible areas using low cost, easily deployed equipment. The basic premise is to suspend a tiny video camera at an altitude of 10 - 200 meters over the area to be surveyed. The TV camera supports at altitude by wind or balloon. The technical challenges regard the means by which the camera is suspended. Such a system may be used by military or police forces or by civil authorities for rescue missions or assessment of natural disasters. The method may be further developed for military applications by integrating the surveillance task with deployment of munitions. Key words: air observer, air suspended system, low altitude video observer.

Alexander Bolonkin

2007-01-10T23:59:59.000Z

369

Hidden variables or hidden theories?  

E-Print Network [OSTI]

We show that a modified Relativity Principle could explain in a "classical" way the strange correlations of entangled photons. We propose a gedanken experiment with balls and boxes that predicts the same distribution of probability of the Quantum Mechanics in the case of the EPR experiment with a pair of entangled photons meeting a pair of polarizers. In the light of this gedanken experiment, we find an alternative description of the real EPR experiment postulating the existence of two observers (one for each polarizer) embedded in two locally anisotropic spacetimes. In our model there is no need to invoke quantum non separability or instantaneous action at distance.

A. Feoli

2006-09-08T23:59:59.000Z

370

Evaluation of cloud fraction and its radiative effect simulated by IPCC AR4 global models against ARM surface observations  

SciTech Connect (OSTI)

Cloud Fraction (CF) is the dominant modulator of radiative fluxes. In this study, we evaluate CF simulations in the IPCC AR4 GCMs against ARM ground measurements, with a focus on the vertical structure, total amount of cloud and its effect on cloud shortwave transmissivity, for both inter-model deviation and model-measurement discrepancy. Our intercomparisons of three CF or sky-cover related dataset reveal that the relative differences are usually less than 10% (5%) for multi-year monthly (annual) mean values, while daily differences are quite significant. The results also show that the model-observation and the inter-model deviations have a similar magnitude for the total CF (TCF) and the normalized cloud effect, and they are twice as large as the surface downward solar radiation and cloud transmissivity. This implies that the other cloud properties, such as cloud optical depth and height, have a similar magnitude of disparity to TCF among the GCMs, and suggests that a better agreement among the GCMs in solar radiative fluxes could be the result of compensating errors in either cloud vertical structure, cloud optical depth or cloud fraction. Similar deviation pattern between inter-model and model-measurement suggests that the climate models tend to generate larger bias against observations for those variables with larger inter-model deviation. The simulated TCF from IPCC AR4 GCMs are very scattered through all seasons over three ARM sites: Southern Great Plains (SGP), Manus, Papua New Guinea and North Slope of Alaska (NSA). The GCMs perform better at SGP than at Manus and NSA in simulating the seasonal variation and probability distribution of TCF; however, the TCF in these models is remarkably underpredicted and cloud transmissivity is less susceptible to the change of TCF than the observed at SGP. Much larger inter-model deviation and model bias are found over NSA than the other sites in estimating the TCF, cloud transmissivity and cloud-radiation interaction, suggesting that the Arctic region continues to challenge cloud simulations in climate models. Most of the GCMs tend to underpredict CF and fail to capture the seasonal variation of CF at middle and low levels in the tropics. The high altitude CF is much larger in the GCMs than the observation and the inter-model variability of CF also reaches maximum at high levels in the tropics. Most of the GCMs tend to underpredict CF by 50-150% relative to the measurement average at low and middle levels over SGP. While the GCMs generally capture the maximum CF in the boundary layer and vertical variability, the inter-model deviation is largest near surface over the Arctic. The internal variability of CF simulated in ensemble runs with the same model is very minimal.

Qian, Yun; Long, Charles N.; Wang, Hailong; Comstock, Jennifer M.; McFarlane, Sally A.; Xie, Shaocheng

2012-02-17T23:59:59.000Z

371

Where and how long ago was water in the western North Atlantic ventilated? Maximum entropy inversions of bottle data from WOCE line A20  

E-Print Network [OSTI]

Gull (1991), Bayesian maximum entropy image reconstruction,F. Primeau (2006), A maximum entropy approach to water massSouth- ern Ocean? A maximum entropy approach to global water

Holzer, Mark; Primeau, Francois W; Smethie, William M; Khatiwala, Samar

2010-01-01T23:59:59.000Z

372

Academic Writing Observation Papers  

E-Print Network [OSTI]

a particular action and did not notice something about the people involved. Note what you did not notice observations. People: If the setting is crowded, choose a particular group (or groups) or focus on random paper around a research question: For example, you may be interested in power relations, interactions

373

Academic Writing Observation Papers  

E-Print Network [OSTI]

a particular action and did not notice something about the people involved. Note what you did not notice observations. People: If the setting is crowded, choose a particular group (or groups) or focus on random in power relations, interactions between interpersonal communication processes and other media, or other

374

Global Warming Observations  

E-Print Network [OSTI]

Global Warming Observations: 1. Global temperature has been gradually rising in recent years #15 in range 8000 12000 nm { CFC's, methane and N 2 O important for global warming even though concentra- tions in concentration of \\greenhouse gases" like CO 2 What determines global temperature? Energy budget of earth: 1

Schofield, Jeremy

375

EBONEEUROPEAN BIODIVERSITY OBSERVATION NETWORK  

E-Print Network [OSTI]

EBONEEUROPEAN BIODIVERSITY OBSERVATION NETWORK Geert De Blust, Guy Laurijssens, Hans Van Calster of biodiversity monitoring through close collaboration of users and data providers #12;#12;Design of a monitoring-effectiveness Optimization of biodiversity monitoring through close collaboration of users and data providers Geert De Blust1

376

Solar Dynamics Observatory/ Extreme Ultraviolet Variability Experiment  

E-Print Network [OSTI]

Solar Dynamics Observatory/ EVE Extreme Ultraviolet Variability Experiment Frequently Asked and model solar extreme ultraviolet irradiance variations due to solar flares, solar rotation, and solar and structure of the Sun. What is solar variability? Solar radiation varies on all time scales ranging from

Mojzsis, Stephen J.

377

Variable Speed Pumping for Level Control  

E-Print Network [OSTI]

The purpose of this paper is to describe an application of variable speed pumping to level control of an industrial process. Topics include a comparison of the process using control valves with a variable speed system, an energy savings and cost...

Vasel, M.

1982-01-01T23:59:59.000Z

378

Practical evaluation of action-angle variables  

SciTech Connect (OSTI)

A practical method is described for establishing action-angle variables for a Hamiltonian system. That is, a given nearly integrable Hamiltonian is divided into an exactly integrable system plus a perturbation in action-angle form. The transformation of variables, which is carried out using a few short trajectory integrations, permits a rapid determination of trajectory properties throughout a phase space volume.

Boozer, A.H.

1984-02-01T23:59:59.000Z

379

Quantum Computing and Hidden Variables Scott Aaronson #  

E-Print Network [OSTI]

Quantum Computing and Hidden Variables Scott Aaronson # Institute for Advanced Study, Princeton of a hidden variable, then we could e#ciently solve problems that are believed to be intractable even powerful than the quantum computing model. PACS numbers: 03.65.Ta, 03.65.Ud, 03.67.Lx, 02.70.­c I

Aaronson, Scott

380

Deutsch-Jozsa algorithm for continuous variables  

E-Print Network [OSTI]

We present an idealized quantum continuous variable analog of the Deutsch-Jozsa algorithm which can be implemented on a perfect continuous variable quantum computer. Using the Fourier transformation and XOR gate appropriate for continuous spectra we show that under ideal operation to infinite precision that there is an infinite reduction in number of query calls in this scheme.

Arun K. Pati; Samuel L. Braunstein

2002-07-18T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

THE MULTI-USE STEINEL VARIABLE TEMPERATURE  

E-Print Network [OSTI]

THE MULTI-USE STEINEL VARIABLE TEMPERATURE ELECTRONICALLY CONTROLLED HEAT GUNTEMPERATURE RANGE 212 at the outlet nozzle will bum flesh. Do not tum on Heat Gun with hand in front of nozzle. DO NOT USE NEAR equipment Specifications Temperature Variable from 212" F to 1100 F Watts 1500W Weight 1.5 lbs. Supply

Kleinfeld, David

382

THE MULTI-USE STEINEL VARIABLE TEMPERATURE  

E-Print Network [OSTI]

THE MULTI-USE STEINEL VARIABLE TEMPERATURE ELECTRONICALLY CONTROLLED HEAT GUNTEMPERATURE RANGE 212 at the outlet nozzle will bum flesh. Do not tum on Heat Gun with hand in front of nozzle. DO NOT USE NEAR equipment Specifications Temperature Variable from 212 F to 1100 F Watts 1500W Weight 1.5 lbs. Supply

Kleinfeld, David

383

A Search for Fast X-ray Variability from Active Galactic Nuclei using Swift  

E-Print Network [OSTI]

Blazars are a class of active galactic nuclei (AGNs) known for their very rapid variabilty in the high energy regions of the electromagnetic spectrum. Despite this known fast variability, X-ray observations have generally not revealed variability in blazars with rate doubling or halving timescales less than approximately 15 min. Since its launch, the Swift X-ray Telescope has obtained 0.2-10 keV X-ray data on 143 AGNs, including blazars, through intense target of opportunity observations that can be analyzed in a multiwavelength context and used to model jet parameters, particularly during flare states. We have analyzed this broad Swift data set in a search for short timescale variability in blazars that could limit the size of the emission region in the blazar jet. While we do find several low-significance possible flares with potential indications of rapid variability, we find no strong evidence for rapid ($energy band for the AGNs analy...

Pryal, Matthew; Stroh, Michael

2015-01-01T23:59:59.000Z

384

Fermi LAT Observations of LS I +61 303: First Detection of an Orbital Modulation in GeV Gamma Rays  

SciTech Connect (OSTI)

This Letter presents the first results from the observations of LS I +61{sup o}303 using Large Area Telescope data from the Fermi Gamma-Ray Space Telescope between 2008 August and 2009 March. Our results indicate variability that is consistent with the binary period, with the emission being modulated at 26.6 {+-} 0.5 days. This constitutes the first detection of orbital periodicity in high-energy gamma rays (20 MeV-100 GeV, HE). The light curve is characterized by a broad peak after periastron, as well as a smaller peak just before apastron. The spectrum is best represented by a power law with an exponential cutoff, yielding an overall flux above 100 MeV of 0.82 {+-} 0.03(stat) {+-} 0.07(syst) 10{sup -6} ph cm{sup -2} s{sup -1}, with a cutoff at 6.3 {+-} 1.1(stat) {+-} 0.4(syst) GeV and photon index {Gamma} = 2.21 {+-} 0.04(stat) {+-} 0.06(syst). There is no significant spectral change with orbital phase. The phase of maximum emission, close to periastron, hints at inverse Compton scattering as the main radiation mechanism. However, previous very high-energy gamma ray (>100 GeV, VHE) observations by MAGIC and VERITAS show peak emission close to apastron. This and the energy cutoff seen with Fermi suggest that the link between HE and VHE gamma rays is nontrivial.

Abdo, A.A.; /Federal City Coll. /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Atwood, W.B.; /UC, Santa Cruz; Axelsson, M.; /Stockholm U., OKC /Stockholm U.; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, G.; /INFN, Trieste /Trieste U.; Bastieri, D.; /INFN, Padua /Padua U.; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Blandford, R.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, E.D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique /Washington U., Seattle /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /Milan Polytechnic /DAPNIA, Saclay /ASDC, Frascati /INFN, Perugia /Perugia U. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /DAPNIA, Saclay /Naval Research Lab, Wash., D.C. /George Mason U. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Montpellier U. /Sonoma State U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /Stockholm U. /DAPNIA, Saclay /NASA, Goddard /CSST, Baltimore /ASDC, Frascati /Naval Research Lab, Wash., D.C. /INFN, Trieste /Pavia U. /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /UC, Santa Cruz /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /SLAC /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Grenoble, CEN; /more authors..

2012-04-02T23:59:59.000Z

385

Chandra and ASCA Observations of the X-ray-brightest T-Tauri Stars in the Rho Ophiuchi Cloud  

E-Print Network [OSTI]

We present the Chandra ACIS and ASCA GIS results for a series of four long-term observations on DoAr 21, ROXs 21 and ROXs 31; the X-ray brightest T-Tauri stars (TTSs) in the Rho Ophiuchi cloud. In the four observations with a net exposure of ~600 ksec, we found six, three and two flares from DoAr 21, ROXs 21 and ROXs 31, respectively; hence the flare rate is fairly high. The spectra of DoAr 21 are well fitted with a single-temperature plasma model, while those of ROXs 21 and ROXs 31 need an additional soft plasma component. Since DoAr 21 is younger (~10^5 yr) than ROXs 21 and ROXs 31 (~10^6 yr), these results may indicate that the soft component gradually increases as T-Tauri stars age. The abundances are generally sub-solar and vary from element to element. Both high-FIP (first ionization potential) and low-FIP elements show enhancement over the mean abundances. An unusual giant flare is detected from ROXs 31. The peak luminosity and temperature are ~10^33 ergs s^-1 and ~10 keV, respectively. The temperature reaches its peak value before the flux maximum, and is nearly constant (4--5 keV) during the decay phase, indicating successive energy release during the flare. The abundances and absorption show dramatic variability from the quiescent to flare phase.

Kensuke Imanishi; Masahiro Tsujimoto; Katsuji Koyama

2002-02-15T23:59:59.000Z

386

THE CARINA PROJECT. VI. THE HELIUM-BURNING VARIABLE STARS  

SciTech Connect (OSTI)

We present new optical (BVI) time-series data for the evolved variable stars in the Carina dwarf spheroidal galaxy. The quality of the data and the observing strategy allowed us to identify 14 new variable stars. Eight out of the 14 are RR Lyrae (RRL) stars, 4 are Anomalous Cepheids (ACs), and 2 are geometrical variables. Comparison of the period distribution for the entire sample of RRLs with similar distributions in nearby dwarf spheroidal galaxies and in the Large Magellanic Cloud indicates that the old stellar populations in these systems share similar properties. This finding is also supported by the RRL distribution in the Bailey diagram. On the other hand, the period distribution and the Bailey diagram of ACs display significant differences among the above stellar systems. This evidence suggests that the properties of intermediate-age stellar populations might be affected both by environmental effects and structural parameters. We use the BV Period-Wesenheit (PW) relation of RRLs together with evolutionary prescriptions and find a true distance modulus of 20.09 {+-} 0.07 (intrinsic) {+-} 0.1 (statistical) mag that agrees quite well with similar estimates available in the literature. We identified four peculiar variables. Taking into account their position in the Bailey diagram and in the BV PW relation, two of them (V14 and V149) appear to be candidate ACs, while two (V158 and V182) might be peculiar RRLs. In particular, the variable V158 has a period and a V-band amplitude very similar to the low-mass RRL-RRLR-02792-recently identified by Pietrzynski et al. in the Galactic bulge.

Coppola, G.; Marconi, M.; Ripepi, V.; Dall'Ora, M.; Musella, I. [INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, I-80131 Napoli (Italy); Stetson, P. B. [Dominion Astrophysical Observatory, NRC-Herzberg, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Bono, G.; Buonanno, R. [Dipartimento di Fisica-Universita di Roma Tor Vergata, Via della Ricerca Scientifica 1, I-00133 Roma (Italy); Fabrizio, M. [INAF-Osservatorio Astronomico di Collurania, via M. Maggini, I-64100 Teramo (Italy); Ferraro, I.; Iannicola, G.; Pulone, L. [INAF-Osservatorio Astronomico di Roma, Via Frascati 33, I-00040 Monte Porzio Catone (Italy); Fiorentino, G. [INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Monelli, M. [Instituto de Astrofisica de Canarias, Calle Via Lactea s/n, E-38205 La Laguna, Tenerife (Spain); Nonino, M. [INAF-Osservatorio Astronomico di Trieste, via G. B. Tiepolo 11, I-40131 Trieste (Italy); Thevenin, F. [Universite de Nice-Sophia Antipolis, Lab. Lagrange, UMR 7293, Observatoire de la Cote dAzur, BP 4229, F-06304 Nice (France); Walker, A. R., E-mail: coppola@na.astro.it [Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, Casilla 603, La Serena (Chile)

2013-09-20T23:59:59.000Z

387

Asphericity and clumpiness in the winds of Luminous Blue Variables  

E-Print Network [OSTI]

We present the first systematic spectropolarimetric study of Luminous Blue Variables (LBVs) in the Galaxy and the Magellanic Clouds, in order to investigate the geometries of their winds. We find that at least half of our sample show changes in polarization across the strong H$\\alpha$ emission line, indicating that the light from the stars is intrinsically polarized and therefore that asphericity already exists at the base of the wind. Multi-epoch spectropolarimetry on four targets reveals variability in their intrinsic polarization. Three of these, AG Car, HR Car and P Cyg, show a position angle (PA) of polarization which appears random with time. Such behaviour can be explained by the presence of strong wind-inhomogeneities, or `clumps' within the wind. Only one star, R 127, shows variability at a constant PA, and hence evidence for axi-symmetry as well as clumpiness. However, if viewed at low inclination, and at limited temporal sampling, such a wind would produce a seemingly random polarization of the type observed in the other three stars. Time-resolved spectropolarimetric monitoring of LBVs is therefore required to determine if LBV winds are axi-symmetric in general. The high fraction of LBVs ($>$ 50%) showing intrinsic polarization is to be compared with the lower $\\sim$ 20-25 % for similar studies of their evolutionary neighbours, O supergiants and Wolf-Rayet stars. We anticipate that this higher incidence is due to the lower effective gravities of the LBVs, coupled with their variable temperatures within the bi-stability jump regime. This is also consistent with the higher incidence of wind asphericity that we find in LBVs with strong H$\\alpha$ emission and recent (last $\\sim$ 10 years) strong variability.

Ben Davies; Rene D. Oudmaijer; Jorick S. Vink

2005-05-17T23:59:59.000Z

388

Cyclic Variability During the Transition Between Spark-ignited Combustion and HCCI  

SciTech Connect (OSTI)

Experimental observations of cyclic variability are described for the transition between conventional spark-ignited (SI) propagating-flame combustion and homogeneous charge compression ignition (HCCI) combustion in a single-cylinder, stoichiometrically fueled, gasoline engine. The engine under study is equipped with a fully variable valve actuation (VVA) system which was used to control the levels of internal exhaust gas recirculation (EGR) to achieve the transition from conventional SI to HCCI. Engine operation in both SI and HCCI modes was observed to be very stable with only minor, stochastic cyclic variability. However, during transitions between these modes, operation was observed to be highly unstable with high levels of cyclic variability and occasionally the engine could not sustain combustion. Analysis of the observed cyclic variability suggests that the transition between SI and HCCI can be described as a sequence of bifurcations in a low-dimensional dynamic map. The deterministic nature of the instabilities observed during the transition suggest that it is possible to make accurate, short-term predictions of combustion performance allowing for the possibility of developing on-line diagnostics and proactive control algorithms for expanding stable HCCI operation and improving transitions between conventional combustion modes and HCCI.

Edwards, Kevin Dean [ORNL; Daw, C Stuart [ORNL; Wagner, Robert M [ORNL; Green Jr, Johney Boyd [ORNL

2006-01-01T23:59:59.000Z

389

NEAR-INFRARED VARIABILITY AMONG YOUNG STELLAR OBJECTS IN THE STAR FORMATION REGION CYGNUS OB7  

SciTech Connect (OSTI)

We present an analysis of near-infrared time-series photometry in J, H, and K bands for about 100 epochs of a 1 Degree-Sign Multiplication-Sign 1 Degree-Sign region of the Lynds 1003/1004 dark cloud in the Cygnus OB7 region. Augmented by data from the Wide-field Infrared Survey Explorer, we identify 96 candidate disk bearing young stellar objects (YSOs) in the region. Of these, 30 are clearly Class I or earlier. Using the Wide-Field Imaging Camera on the United Kingdom Infrared Telescope, we were able to obtain photometry over three observing seasons, with photometric uncertainty better than 0.05 mag down to J Almost-Equal-To 17. We study detailed light curves and color trajectories of {approx}50 of the YSOs in the monitored field. We investigate the variability and periodicity of the YSOs and find the data are consistent with all YSOs being variable in these wavelengths on timescales of a few years. We divide the variability into four observational classes: (1) stars with periodic variability stable over long timescales, (2) variables which exhibit short-lived cyclic behavior, (3) long-duration variables, and (4) stochastic variables. Some YSO variability defies simple classification. We can explain much of the observed variability as being due to dynamic and rotational changes in the disk, including an asymmetric or changing blocking fraction, changes to the inner disk hole size, as well as changes to the accretion rate. Overall, we find that the Class I:Class II ratio of the cluster is consistent with an age of <1 Myr, with at least one individual, wildly varying source {approx}100, 000 yr old. We have also discovered a Class II eclipsing binary system with a period of 17.87 days.

Wolk, Scott J.; Rice, Thomas S. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Aspin, Colin [Institute for Astronomy, University of Hawaii at Manoa, 640 North Aohoku Place, Hilo, HI 96720 (United States)

2013-08-20T23:59:59.000Z

390

Liquid-Liquid Transition at Tg and Stable-Glass Phase Nucleation Rate Maximum at the Kauzmann Temperature TK  

E-Print Network [OSTI]

An undercooled liquid is unstable. The driving force of the glass transition at Tg is a change of the undercooled-liquid Gibbs free energy. The classical Gibbs free energy change for a crystal formation is completed including an enthalpy saving. The crystal growth critical nucleus is used as a probe to observe the Laplace pressure change Dp accompanying the enthalpy change -Vm*Dp at Tg where Vm is the molar volume. A stable glass-liquid transition model predicts the specific heat jump of fragile liquids at temperatures smaller than Tg, the Kauzmann temperature TK where the liquid entropy excess with regard to crystal goes to zero, the equilibrium enthalpy between TK and Tg, the maximum nucleation rate at TK of superclusters containing magic atom numbers, and the equilibrium latent heats at Tg and TK. Strong-to-fragile and strong-to-strong liquid transitions at Tg are also described and all their thermodynamic parameters are determined from their specific heat jumps. The existence of fragile liquids quenched in the amorphous state, which do not undergo liquid-liquid transition during heating preceding their crystallization, is predicted. Long ageing times leading to the formation at TK of a stable glass composed of superclusters containing up to 147 atoms, touching and interpenetrating, are evaluated from nucleation rates.

Robert Felix Tournier

2014-04-25T23:59:59.000Z

391

Binary versus non-binary information in real time series: empirical results and maximum-entropy matrix models  

E-Print Network [OSTI]

The dynamics of complex systems, from financial markets to the brain, can be monitored in terms of time series of activity of their fundamental elements (such as stocks or neurons respectively). While the main focus of time series analysis is on the magnitude of temporal increments, a significant piece of information is encoded into the binary projection (i.e. the sign) of such increments. In this paper we provide further evidence of this by showing strong nonlinear relationships between binary and non-binary properties of financial time series. We then introduce an information-theoretic approach to the analysis of the binary signature of single and multiple time series. Through the definition of maximum-entropy ensembles of binary matrices, we quantify the information encoded into the simplest binary properties of real time series and identify the most informative property given a set of measurements. Our formalism is able to replicate the observed binary/non-binary relations very well, and to mathematically...

Almog, Assaf

2014-01-01T23:59:59.000Z

392

The winds of Luminous Blue Variables and the Mass of AG Car  

E-Print Network [OSTI]

We present radiation-driven wind models for Luminous Blue Variables (LBVs) and predict their mass-loss rates. A comparison between our predictions and the observations of AG Car shows that the variable mass loss behaviour of LBVs is due the recombination/ionisation of Fe IV/III and Fe III/II. We also derive a present-day mass of 35 Msun for AG Car.

Jorick S. Vink; Alex de Koter

2002-07-15T23:59:59.000Z

393

THE LICK AGN MONITORING PROJECT: VELOCITY-DELAY MAPS FROM THE MAXIMUM-ENTROPY METHOD FOR Arp 151  

SciTech Connect (OSTI)

We present velocity-delay maps for optical H I, He I, and He II recombination lines in Arp 151, recovered by fitting a reverberation model to spectrophotometric monitoring data using the maximum-entropy method. H I response is detected over the range 0-15 days, with the response confined within the virial envelope. The Balmer-line maps have similar morphologies but exhibit radial stratification, with progressively longer delays for H{gamma} to H{beta} to H{alpha}. The He I and He II response is confined within 1-2 days. There is a deficit of prompt response in the Balmer-line cores but strong prompt response in the red wings. Comparison with simple models identifies two classes that reproduce these features: free-falling gas and a half-illuminated disk with a hot spot at small radius on the receding lune. Symmetrically illuminated models with gas orbiting in an inclined disk or an isotropic distribution of randomly inclined circular orbits can reproduce the virial structure but not the observed asymmetry. Radial outflows are also largely ruled out by the observed asymmetry. A warped-disk geometry provides a physically plausible mechanism for the asymmetric illumination and hot spot features. Simple estimates show that a disk in the broad-line region of Arp 151 could be unstable to warping induced by radiation pressure. Our results demonstrate the potential power of detailed modeling combined with monitoring campaigns at higher cadence to characterize the gas kinematics and physical processes that give rise to the broad emission lines in active galactic nuclei.

Bentz, Misty C.; Barth, Aaron J.; Walsh, Jonelle L. [Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California, Irvine, CA 92697 (United States); Horne, Keith [SUPA Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS (United Kingdom); Bennert, Vardha Nicola; Treu, Tommaso [Physics Department, University of California, Santa Barbara, CA 93106 (United States); Canalizo, Gabriela [Institute of Geophysics and Planetary Physics, University of California, Riverside, CA 92521 (United States); Filippenko, Alexei V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Gates, Elinor L. [Lick Observatory, P.O. Box 85, Mount Hamilton, CA 95140 (United States); Malkan, Matthew A. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90024 (United States); Minezaki, Takeo [Institute of Astronomy, School of Science, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Woo, Jong-Hak, E-mail: mbentz@uci.ed [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Gwanak-gu, Seoul 151-742 (Korea, Republic of)

2010-09-01T23:59:59.000Z

394

The relative contributions of radiative forcing and internal climate variability to the late 20th Century winter drying  

E-Print Network [OSTI]

of anthropogenic climate change and internal climate variability in causing the Mediterranean region's late 20th Panel on Climate Change Fourth Assessment Report. The observed drying was influenced by the robustThe relative contributions of radiative forcing and internal climate variability to the late 20th

395

On Weyl channels being covariant with respect to the maximum commutative group of unitaries  

E-Print Network [OSTI]

We investigate the Weyl channels being covariant with respect to the maximum commutative group of unitary operators. This class includes the quantum depolarizing channel and the "two-Pauli" channel as well. Then, we show that our estimation of the output entropy for a tensor product of the phase damping channel and the identity channel based upon the decreasing property of the relative entropy allows to prove the additivity conjecture for the minimal output entropy for the quantum depolarizing channel in any prime dimesnsion and for the "two Pauli" channel in the qubit case.

G. G. Amosov

2006-08-10T23:59:59.000Z

396

A New Maximum-Likelihood Change Estimator for Two-Pass SAR Coherent Change Detection.  

SciTech Connect (OSTI)

In this paper, we derive a new optimal change metric to be used in synthetic aperture RADAR (SAR) coherent change detection (CCD). Previous CCD methods tend to produce false alarm states (showing change when there is none) in areas of the image that have a low clutter-to-noise power ratio (CNR). The new estimator does not suffer from this shortcoming. It is a surprisingly simple expression, easy to implement, and is optimal in the maximum-likelihood (ML) sense. The estimator produces very impressive results on the CCD collects that we have tested.

Wahl, Daniel E.; Yocky, David A.; Jakowatz, Charles V,

2014-09-01T23:59:59.000Z

397

Application of Maximum Entropy Method to Lattice Field Theory with a Topological Term  

E-Print Network [OSTI]

In Monte Carlo simulation, lattice field theory with a $\\theta$ term suffers from the sign problem. This problem can be circumvented by Fourier-transforming the topological charge distribution $P(Q)$. Although this strategy works well for small lattice volume, effect of errors of $P(Q)$ becomes serious with increasing volume and prevents one from studying the phase structure. This is called flattening. As an alternative approach, we apply the maximum entropy method (MEM) to the Gaussian $P(Q)$. It is found that the flattening could be much improved by use of the MEM.

M. Imachi; Y. Shinno; H. Yoneyama

2003-09-22T23:59:59.000Z

398

Charmonium spectra at finite temperature from QCD sum rules with the maximum entropy method  

E-Print Network [OSTI]

Charmonia spectral functions at finite temperature are studied using QCD sum rules in combination with the maximum entropy method. This approach enables us to directly obtain the spectral function from the sum rules, without having to introduce any specific assumption about its functional form. As a result, it is found that while J/psi and eta_c manifest themselves as significant peaks in the spectral function below the deconfinement temperature T_c, they quickly dissolve into the continuum and almost completely disappear at temperatures between 1.0 T_c and 1.1 T_c.

Philipp Gubler; Kenji Morita; Makoto Oka

2011-08-30T23:59:59.000Z

399

Spectral density analysis of time correlation functions in lattice QCD using the maximum entropy method  

E-Print Network [OSTI]

We study various aspects of extracting spectral information from time correlation functions of lattice QCD by means of Bayesian inference with an entropic prior, the maximum entropy method (MEM). Correlator functions of a heavy-light meson-meson system serve as a repository for lattice data with diverse statistical quality. Attention is given to spectral mass density functions, inferred from the data, and their dependence on the parameters of the MEM. We propose to employ simulated annealing, or cooling, to solve the Bayesian inference problem, and discuss practical issues of the approach.

H. Rudolf Fiebig

2002-10-31T23:59:59.000Z

400

Spectral Functions, Maximum Entropy Method and Unconventional Methods in Lattice Field Theory  

E-Print Network [OSTI]

We present two unconventional methods of extracting information from hadronic 2-point functions produced by Monte Carlo simulations. The first is an extension of earlier work by Leinweber which combines a QCD Sum Rule approach with lattice data. The second uses the Maximum Entropy Method to invert the 2-point data to obtain estimates of the spectral function. The first approach is applied to QCD data, and the second method is applied to the Nambu--Jona-Lasinio model in (2+1)D. Both methods promise to augment the current approach where physical quantities are extracted by fitting to pure exponentials.

Chris Allton; Danielle Blythe; Jonathan Clowser

2002-04-26T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

On Weyl channels being covariant with respect to the maximum commutative group of unitaries  

SciTech Connect (OSTI)

We investigate the Weyl channels being covariant with respect to the maximum commutative group of unitary operators. This class includes the quantum depolarizing channel and the 'two-Pauli' channel as well. Then, we show that our estimation of the output entropy for a tensor product of the phase damping channel and the identity channel based upon the decreasing property of the relative entropy allows to prove the additivity conjecture for the minimal output entropy for the quantum depolarizing channel in any prime dimension and for the two-Pauli channel in the qubit case.

Amosov, Grigori G. [Department of Higher Mathematics, Moscow Institute of Physics and Technology, Dolgoprudny 141700 (Russian Federation)

2007-01-15T23:59:59.000Z

402

Maximum entropy analysis of hadron spectral functions and excited states in quenched lattice QCD  

E-Print Network [OSTI]

Employing the maximum entropy method we extract the spectral functions from meson correlators at four lattice spacings in quenched QCD with the Wilson quark action. We confirm that the masses and decay constants, obtained from the position and the area of peaks, agree well with the results from the conventional exponential fit. For the first excited state, we obtain $m_{\\pi_1} = 660(590)$ MeV, $m_{\\rho_1} = 1540(570)$ MeV, and $f_{\\rho_1} = 0.085(36)$ in the continuum limit.

CP-PACS Collaboration; :; S. Aoki; R. Burkhalter; M. Fukugita; S. Hashimoto; N. Ishizuka; Y. Iwasaki; K. Kanaya; T. Kaneko; Y. Kuramashi; M. Okawa; Y. Taniguchi; A. Ukawa; T. Yamazaki; T. Yoshi

2001-10-16T23:59:59.000Z

403

Abstract--The many different techniques for maximum power point tracking of photovoltaic arrays are discussed. The  

E-Print Network [OSTI]

Abstract--The many different techniques for maximum power point tracking of photovoltaic arrays on implementation. This manuscript should serve as a convenient reference for future work in photovoltaic power generation. Index Terms--maximum power point tracking, MPPT, photovoltaic, PV. I. INTRODUCTION RACKING

Chapman, Patrick

404

On Maximum Available Feedback and PID Control -1 IEEE SMC UK&RI Applied Cybernetics Dr Richard Mitchell 2005  

E-Print Network [OSTI]

On Maximum Available Feedback and PID Control - 1 IEEE SMC UK&RI Applied Cybernetics © Dr Richard Mitchell 2005 ON MAXIMUM AVAILABLE FEEDBACK AND PID CONTROL Dr Richard Mitchell, Cybernetics, University frequencies A recent IEEE SMC Paper describes a robust PID controller whose phase is flat at key frequencies

Mitchell, Richard

405

One of the most clearly established and widely known facts in locomotor physiology is that the maximum force exerted by  

E-Print Network [OSTI]

(musculoskeletal systems and man-made machines such as piston engines, jets, and electric motors that use rotary) that simulated in vivo maximum musculoskeletal performance was proportional to muscle mass0.83, a significant increase in the scaling exponent over that of maximum isometric force output. The dynamic performance

Marden, James

406

Blind Joint Maximum Likelihood Channel Estimation and Data Detection for Single-Input Multiple-Output Systems  

E-Print Network [OSTI]

Blind Joint Maximum Likelihood Channel Estimation and Data Detection for Single-Input Multiple of Southampton, Southampton SO17 1BJ, U.K. Abstract--A blind adaptive scheme is proposed for joint maximum. A simulation example is used to demon- strate the effectiveness of this joint ML optimization scheme for blind

Chen, Sheng

407

Infrared Colors and Variability of Evolved Stars from COBE DIRBE Data  

E-Print Network [OSTI]

For a complete 12 micron flux-limited sample of 207 IRAS sources, we have extracted light curves in seven infrared bands between 1.25 - 60 microns using the database of the DIRBE instrument on the COBE satellite. Using previous infrared surveys, we filtered these light curves to remove datapoints affected by nearby companions. In the time-averaged DIRBE color-color plots, we find clear segregation of semi-regulars, Mira variables, carbon stars, OH/IR stars, and red giants without circumstellar dust and with little or no visual variation. The DIRBE 1.25 - 25 micron colors become progressively redder and the variability in the DIRBE database increases along the oxygen-rich sequence non-dusty slightly varying red giants -> SRb/Lb -> SRa -> Mira -> OH/IR and the carbon-rich SRb/Lb -> Mira sequence. This supports previous assertions that these are evolutionary sequences involving the continued production and ejection of dust. Carbon stars are redder than oxygen-rich stars for the same variability type, except in the F(12)/F(25) ratio. Of the 28 sources in the sample not previous noted to be variable, 18 are clearly variable in the DIRBE data, with amplitudes of variation of ~0.9 magnitudes at 4.9 microns and ~0.6 magnitudes at 12 microns, consistent with them being very dusty Mira-like variables. The light curves of the semi-regular variable L2 Pup are particularly remarkable. The maxima at 1.25, 2.2, and 3.5 microns occur 10 - 20 days before those at 4.9 and 12 microns, and, at 4.9 and 12 microns, another maximum is seen between the two near-infrared maxima.

Beverly J. Smith

2003-06-20T23:59:59.000Z

408

Observations and Theories of Langmuir Circulation: A Story of Mixing  

E-Print Network [OSTI]

occasion to review the history of this field of study. An underlying theme here is that the study interdisciplinary history; the first half of this work is a brief and eclectic review of this. Much of the research recent observations and the nature of this unexplained variability. 1 Introduction The oceanic surface

Smith, Jerome A.

409

Observationally based assessment of polar amplification of global warming  

E-Print Network [OSTI]

Observationally based assessment of polar amplification of global warming Igor V. Polyakov,1) are similar, and do not support the predicted polar amplification of global warming. The possible moderating amplification of global warming. Intrinsic arctic variability obscures long-term changes, limiting our ability

Bhatt, Uma

410

Quantifying global marine isoprene fluxes using MODIS chlorophyll observations  

E-Print Network [OSTI]

, with considerable spatial and temporal variability, resulting in a global annual total of 0.1 Tg C/yr. Air vegetation [Guenther et al., 1995], with the tropics responsible for most of the global annual total ($500 TgQuantifying global marine isoprene fluxes using MODIS chlorophyll observations Paul I. Palmer

Palmer, Paul

411

Internal and Boundary Observability Estimates for the Heterogeneous Maxwell's System  

SciTech Connect (OSTI)

Observability estimates for Maxwell's system with variable coefficients are established using the differential geometry method recently developed for scalar wave equations.The main tool is that Maxwell's system is reducible to a perturbed vectorial wave equation with a decoupled principal part.

Nicaise, Serge [Universite de Valenciennes et du Hainaut Cambresis, MACS, Institut des Sciences et Techniques de Valenciennes, 59313 Valenciennes Cedex 9 (France)], E-mail: snicaise@univ-valenciennes.fr; Pignotti, Cristina [Dipartimento di Matematica Pura e Applicata, Universita di L'Aquila, Via Vetoio, Loc. Coppito, 67010 L'Aquila (Italy)], E-mail: pignotti@univqaq.it

2006-06-15T23:59:59.000Z

412

A comparison of two variables in relaxation  

E-Print Network [OSTI]

A COMPARISON OF TWO VARIABLES IN RELAXATION A Thesis by PAUL EDWIN TURNER Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE May 1974 Major Subject...: Psychology A COMPARiSON OF TWO VARIABLES IN RELAXATION A Thesis by PAUL EDWIN TURNER Approved as to style and content by: (Chairman of Committ Head of Dep tment Member ?2 J L, ~Xi~ Member M-. ~~2 y May 1974 ABSTRACT A Comparison of Two Variable...

Turner, Paul Edwin

1974-01-01T23:59:59.000Z

413

Essays on Bayesian Time Series and Variable Selection  

E-Print Network [OSTI]

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 vi LIST OF FIGURES FIGURE Page 2.1 Dynamic Model. Given xt, yt is independent of y1:t?1, x1:t?1. . . . . . . 7 2.2 The figure shows estimated value of ? and ?2 from : (a)-(b) Stochastic Approximation approach; (c)-(d) Augmentation approach. In each... Sorenson (1970). 6 Let yt and xt be the p and q dimensional observation and hidden state variable at the time t. Let ? be set of unknown parameter. Figure (2.1) depicts the dynamic relation between yt and xt. The generalized version of state-space model can...

De, Debkumar

2014-05-08T23:59:59.000Z

414

LATE-TIME SPECTRAL OBSERVATIONS OF THE STRONGLY INTERACTING TYPE Ia SUPERNOVA PTF11kx  

SciTech Connect (OSTI)

PTF11kx was a Type Ia supernova (SN Ia) that showed time-variable absorption features, including saturated Ca II H and K lines that weakened and eventually went into emission. The strength of the emission component of H{alpha} gradually increased, implying that the SN was undergoing significant interaction with its circumstellar medium (CSM). These features, and many others, were blueshifted slightly and showed a P-Cygni profile, likely indicating that the CSM was directly related to, and probably previously ejected by, the progenitor system itself. These and other observations led Dilday et al. to conclude that PTF11kx came from a symbiotic nova progenitor like RS Oph. In this work we extend the spectral coverage of PTF11kx to 124-680 rest-frame days past maximum brightness. The late-time spectra of PTF11kx are dominated by H{alpha} emission (with widths of full width at half-maximum intensity Almost-Equal-To 2000 km s{sup -1}), strong Ca II emission features ({approx}10,000 km s{sup -1} wide), and a blue 'quasi-continuum' due to many overlapping narrow lines of Fe II. Emission from oxygen, He I, and Balmer lines higher than H{alpha} is weak or completely absent at all epochs, leading to large observed H{alpha}/H{beta} intensity ratios. The H{alpha} emission appears to increase in strength with time for {approx}1 yr, but it subsequently decreases significantly along with the Ca II emission. Our latest spectrum also indicates the possibility of newly formed dust in the system as evidenced by a slight decrease in the red wing of H{alpha}. During the same epochs, multiple narrow emission features from the CSM temporally vary in strength. The weakening of the H{alpha} and Ca II emission at late times is possible evidence that the SN ejecta have overtaken the majority of the CSM and agrees with models of other strongly interacting SNe Ia. The varying narrow emission features, on the other hand, may indicate that the CSM is clumpy or consists of multiple thin shells.

Silverman, Jeffrey M. [Department of Astronomy, University of Texas, Austin, TX 78712-0259 (United States); Nugent, Peter E.; Filippenko, Alexei V.; Cenko, S. Bradley [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Gal-Yam, Avishay [Benoziyo Center for Astrophysics, The Weizmann Institute of Science, Rehovot 76100 (Israel); Sullivan, Mark [School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom); Howell, D. Andrew [Las Cumbres Observatory Global Telescope Network, Goleta, CA 93117 (United States); Pan, Yen-Chen; Hook, Isobel M., E-mail: jsilverman@astro.as.utexas.edu [Department of Physics (Astrophysics), University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom)

2013-08-01T23:59:59.000Z

415

Spatial Corrections of ROSAT HRI Observations  

E-Print Network [OSTI]

X-ray observations with the ROSAT High Resolution Imager (HRI) often have spatial smearing on the order of 10 arcsec (Morse 1994). This degradation of the intrinsic resolution of the instrument (5 arcsec) can be attributed to errors in the aspect solution associated with the wobble of the space craft or with the reacquisition of the guide stars. We have developed a set of IRAF/PROS and MIDAS/EXSAS routines to minimize these effects. Our procedure attempts to isolate aspect errors that are repeated through each cycle of the wobble. The method assigns a 'wobble phase' to each event based on the 402 second period of the ROSAT wobble. The observation is grouped into a number of phase bins and a centroid is calculated for each sub-image. The corrected HRI event list is reconstructed by adding the sub-images which have been shifted to a common source position. This method has shown approx. 30% reduction of the full width half maximum (FWHM) of an X-ray observation of the radio galaxy 3C 120. Additional examples are presented.

D. E. Harris; J. D. Silverman; G. Hasinger; I. Lehmann

1998-11-08T23:59:59.000Z

416

Quantum maximum-entropy principle for closed quantum hydrodynamic transport within a Wigner function formalism  

SciTech Connect (OSTI)

By introducing a quantum entropy functional of the reduced density matrix, the principle of quantum maximum entropy is asserted as fundamental principle of quantum statistical mechanics. Accordingly, we develop a comprehensive theoretical formalism to construct rigorously a closed quantum hydrodynamic transport within a Wigner function approach. The theoretical formalism is formulated in both thermodynamic equilibrium and nonequilibrium conditions, and the quantum contributions are obtained by only assuming that the Lagrange multipliers can be expanded in powers of ({h_bar}/2{pi}){sup 2}. In particular, by using an arbitrary number of moments, we prove that (1) on a macroscopic scale all nonlocal effects, compatible with the uncertainty principle, are imputable to high-order spatial derivatives, both of the numerical density n and of the effective temperature T; (2) the results available from the literature in the framework of both a quantum Boltzmann gas and a degenerate quantum Fermi gas are recovered as a particular case; (3) the statistics for the quantum Fermi and Bose gases at different levels of degeneracy are explicitly incorporated; (4) a set of relevant applications admitting exact analytical equations are explicitly given and discussed; (5) the quantum maximum entropy principle keeps full validity in the classical limit, when ({h_bar}/2{pi}){yields}0.

Trovato, M. [Dipartimento di Matematica, Universita di Catania, Viale A. Doria, I-95125 Catania (Italy); Reggiani, L. [Dipartimento di Ingegneria dell' Innovazione and CNISM, Universita del Salento, Via Arnesano s/n, I-73100 Lecce (Italy)

2011-12-15T23:59:59.000Z

417

Observations of Edge Turbulence  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the ContributionsArmsSpeedingSpeedingUnder Well-ControlledObservation ofofEdge Turbulence

418

Performance of twist-coupled blades on variable speed rotors  

SciTech Connect (OSTI)

The load mitigation and energy capture characteristics of twist-coupled HAWT blades that are mounted on a variable speed rotor are investigated in this paper. These blades are designed to twist toward feather as they bend with pretwist set to achieve a desirable twist distribution at rated power. For this investigation, the ADAMS-WT software has been modified to include blade models with bending-twist coupling. Using twist-coupled and uncoupled models, the ADAMS software is exercised for steady wind environments to generate C{sub p} curves at a number of operating speeds to compare the efficiencies of the two models. The ADAMS software is also used to generate the response of a twist-coupled variable speed rotor to a spectrum of stochastic wind time series. This spectrum contains time series with two mean wind speeds at two turbulence levels. Power control is achieved by imposing a reactive torque on the low speed shaft proportional to the RPM squared with the coefficient specified so that the rotor operates at peak efficiency in the linear aerodynamic range, and by limiting the maximum RPM to take advantage of the stall controlled nature of the rotor. Fatigue calculations are done for the generated load histories using a range of material exponents that represent materials from welded steel to aluminum to composites, and results are compared with the damage computed for the rotor without twist-coupling. Results indicate that significant reductions in damage are achieved across the spectrum of applied wind loading without any degradation in power production.

Lobitz, D.W.; Veers, P.S.; Laino, D.J.

1999-12-07T23:59:59.000Z

419

A search for rapid optical variability in radio-quiet quasars  

E-Print Network [OSTI]

The detection of rapid variability on a time-scale of hours in radio-quiet quasars (RQQSOs) could be a powerful discriminator between starburst, accretion disc and relativistic jet models of these sources. This paper contains an account of a dedicated search for rapid optical variability in RQQSOs. The technique used differential photometry between the RQQSO and stars in the same field of view of the CCD. The 23 RQQSOs that were observed all have high luminosities (-27 1. The total amount of observation time was about 60 hours and these observations are part of an ongoing programme, started in September 1990, to search for rapid variability in RQQSOs. No evidence for short-term variability greater than about 0.1 magnitudes was detected in any of the 23 sources, however long-term variability was recorded for the radio-quiet quasar PG 2112+059. The finding charts are included here because they identify the RQQSO and the reference stars used in the photometry, and hence are available for use by other observers.

M. Rabbette; B. McBreen; N. Smith; S. Steel

1998-03-09T23:59:59.000Z

420

Thoracic target volume delineation using various maximum-intensity projection computed tomography image sets for radiotherapy treatment planning  

SciTech Connect (OSTI)

Purpose: Four-dimensional computed tomography (4D-CT) is commonly used to account for respiratory motion of target volumes in radiotherapy to the thorax. From the 4D-CT acquisition, a maximum-intensity projection (MIP) image set can be created and used to help define the tumor motion envelope or the internal gross tumor volume (iGTV). The purpose of this study was to quantify the differences in automatically contoured target volumes for usage in the delivery of stereotactic body radiation therapy using MIP data sets generated from one of the four methods: (1) 4D-CT phase-binned (PB) based on retrospective phase calculations, (2) 4D-CT phase-corrected phase-binned (PC-PB) based on motion extrema, (3) 4D-CT amplitude-binned (AB), and (4) cine CT built from all available images. Methods: MIP image data sets using each of the four methods were generated for a cohort of 28 patients who had prior thoracic 4D-CT scans that exhibited lung tumor motion of at least 1 cm. Each MIP image set was automatically contoured on commercial radiation treatment planning system. Margins were added to the iGTV to observe differences in the final simulated planning target volumes (PTVs). Results: For all patients, the iGTV measured on the MIP generated from the entire cine CT data set (iGTV{sub cine}) was the largest. Expressed as a percentage of iGTV{sub cine}, 4D-CT iGTV (all sorting methods) ranged from 83.8% to 99.1%, representing differences in the absolute volume ranging from 0.02 to 4.20 cm{sup 3}; the largest average and range of 4D-CT iGTV measurements was from the PC-PB data set. Expressed as a percentage of PTV{sub cine} (expansions applied to iGTV{sub cine}), the 4D-CT PTV ranged from 87.6% to 99.6%, representing differences in the absolute volume ranging from 0.08 to 7.42 cm{sup 3}. Regions of the measured respiratory waveform corresponding to a rapid change of phase or amplitude showed an increased susceptibility to the selection of identical images for adjacent bins. Duplicate image selection was most common in the AB implementation, followed by the PC-PB method. The authors also found that the image associated with the minimum amplitude measurement did not always correlate with the image that showed maximum tumor motion extent. Conclusions: The authors identified cases in which the MIP generated from a 4D-CT sorting process under-represented the iGTV by more than 10% or up to 4.2 cm{sup 3} when compared to the iGTV{sub cine}. They suggest utilization of a MIP generated from the full cine CT data set to ensure maximum inclusive tumor extent.

Zamora, David A.; Riegel, Adam C.; Sun Xiaojun; Balter, Peter; Starkschall, George; Mawlawi, Osama; Pan Tinsu [Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

2010-11-15T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Observing the Inflationary Reheating  

E-Print Network [OSTI]

Reheating is the the epoch which connects inflation to the subsequent hot Big-Bang phase. Conceptually very important, this era is however observationally poorly known. We show that the current Planck satellite measurements of the Cosmic Microwave Background (CMB) anisotropies constrain the kinematic properties of the reheating era for most of the inflationary models. This result is obtained by deriving the marginalized posterior distributions of the reheating parameter for about 200 models taken in Encyclopaedia Inflationaris. Weighted by the statistical evidence of each model to explain the data, we show that the Planck 2013 measurements induce an average reduction of the posterior-to-prior volume by 40%. Making some additional assumptions on reheating, such as specifying a mean equation of state parameter, or focusing the analysis on peculiar scenarios, can enhance or reduce this constraint. Our study also indicates that the Bayesian evidence of a model can substantially be affected by the reheating properties. The precision of the current CMB data is therefore such that estimating the observational performance of a model now requires to incorporate information about its reheating history.

Jerome Martin; Christophe Ringeval; Vincent Vennin

2014-10-29T23:59:59.000Z

422

Variability in Measured Space Temperatures in 60 Homes  

SciTech Connect (OSTI)

This report discusses the observed variability in indoor space temperature in a set of 60 homes located in Florida, New York, Oregon, and Washington. Temperature data were collected at 15-minute intervals for an entire year, including living room, master bedroom, and outdoor air temperature (Arena, et. al). The data were examined to establish the average living room temperature for the set of homes for the heating and cooling seasons, the variability of living room temperature depending on climate, and the variability of indoor space temperature within the homes. The accuracy of software-based energy analysis depends on the accuracy of input values. Thermostat set point is one of the most influential inputs for building energy simulation. Several industry standards exist that recommend differing default thermostat settings for heating and cooling seasons. These standards were compared to the values calculated for this analysis. The data examined for this report show that there is a definite difference between the climates and that the data do not agree well with any particular standard.

Roberts, D.; Lay, K.

2013-03-01T23:59:59.000Z

423

The Energy-Dependence of GRB Minimum Variability Timescales  

E-Print Network [OSTI]

We constrain the minimum variability timescales for 938 GRBs observed by the Fermi/GBM instrument prior to July 11, 2012. The tightest constraints on progenitor radii derived from these timescales are obtained from light curves in the hardest energy channel. In the softer bands -- or from measurements of the same GRBs in the hard X-rays from Swift -- we show that variability timescales tend to be a factor 2--3 longer. Applying a survival analysis to account for detections and upper limits, we find median minimum timescale in the rest frame for long-duration and short-duration GRBs of 45 ms and 10 ms, respectively. Fewer than 10% of GRBs show evidence for variability on timescales below 2 ms. These shortest timescales require Lorentz factors $\\gtrsim 400$ and imply typical emission radii $R \\approx 1 {\\times} 10^{14}$ cm for long-duration GRBs and $R \\approx 3 {\\times} 10^{13}$ cm for short-duration GRBs. We discuss implications for the GRB fireball model and investigate whether GRB minimum timescales evolve w...

Golkhou, V Zach; Littlejohns, Owen M

2015-01-01T23:59:59.000Z

424

Variable volume architecture : expanding the boundary  

E-Print Network [OSTI]

Research into the creation of a Variable Volume Architecture is explored through a series of proposals and projects. An argument is established to develop the means and methods of achieving an architecture of transformation. ...

Saheba, Asheshh (Asheshh Mohit), 1972-

2001-01-01T23:59:59.000Z

425

Inserting Group Variables into Fluid Mechanics  

E-Print Network [OSTI]

A fluid, like a quark-gluon plasma, may possess degrees of freedom indexed by a group variable, which retains its identity even in the fluid/continuum description. Conventional Eulerian fluid mechanics is extended to encompass this possibility.

R. Jackiw

2004-10-28T23:59:59.000Z

426

Energy Savings of Variable Speed Motors  

E-Print Network [OSTI]

This paper investigates the energy savings available by utilizing variable speed motors on pump and fan applications. Conventional control of flow or pressure in process plants is normally accomplished by throttling the various streams with control...

Fishel, F. D.

1979-01-01T23:59:59.000Z

427

Variable-Rate State Gasoline Taxes  

E-Print Network [OSTI]

J Bradshaw, "SLate F~es Gasoline Tax So ~t Wdl Rise," TheVarlable-Rate State Gasoline Taxers Jeffrey Ang-Olson MartinVariable-Rate State Gasoline Taxes Jeffrey Ang-Olson

Ang-Olson, Jeffrey; Wachs, Martin; Taylor, Brian D.

2000-01-01T23:59:59.000Z

428

UselessVariable Elimination Olin Shivers  

E-Print Network [OSTI]

flow analysis on the CPS inter­ mediate form. (I use a CPS representation essentially identical­passing style (CPS) intermediate representations, continuation variables are frequently passed around loops

Shivers, Olin

429

Hybrid permanent magnet and variable reluctance generator  

SciTech Connect (OSTI)

This patent describes a hybrid electrical generator. It comprises: a permanent magnet generator having a permanent magnet rotor mounted on a shaft, the permanent magnet generator providing an output voltage over an operating range which falls in response to an increasing electrical load; a variable reluctance generator having a rotor mounted on the shaft with excitation of a stator of the variable reluctance generator being provided from the permanent magnet generator, the variable reluctance generator providing an output voltage which varies in response to an increasing electrical load over an operating range; and a voltage regulator, responsive to combined output voltages of the generators, for controlling the output voltage provided by the variable reluctance generator.

Vaidya, J.; Belanger, D.J.

1990-09-25T23:59:59.000Z

430

The Evolutionary Status of M3 RR Lyrae Variables: Breakdown of the Canonical Framework?  

E-Print Network [OSTI]

In order to test the prevailing paradigm of horizontal-branch (HB) stellar evolution, we use the large databases of measured RR Lyrae parameters for the globular cluster M3 (NGC 5272) recently provided by Bakos et al. and Corwin & Carney. We compare the observed distribution of fundamentalized periods against the predictions of synthetic HBs. The observed distribution shows a sharp peak at P_f ~ 0.55 d, which is primarily due to the RRab variables, whereas the model predictions instead indicate that the distribution should be more uniform in P_f, with a buildup of variables with shorter periods (P_f < 0.5 d). Detailed statistical tests show, for the first time, that the observed and predicted distributions are incompatible with one another at a high significance level. We show that the sharp peak in the M3 period distribution receives a significant contribution from the Blazhko variables in the cluster. We also show that M15 (NGC 7078) and M68 (NGC 4590) show similar peaks in their P_f distributions, which in spite of being located at a similar P_f value as M3's, can be primarily ascribed to the RRc variables. Again similar to M3, a demise of RRc variables towards the blue edge of the instability strip is present in these two globulars. This is again in sharp contrast with the evolutionary scenario, which also foresees a strong buildup of RRc variables with short periods in OoII globulars. We speculate that, in OoI systems, RRab variables may get "trapped" close to the transition line between RRab and RRc pulsators as they evolve to the blue, whereas in OoII systems it is the RRc variables that may get "trapped" instead, as they evolve to the red, before changing their pulsation mode to RRab. Such a scenario is supported by the available CMDs and Bailey diagrams for M3, M15, and M68.

M. Catelan

2003-09-05T23:59:59.000Z

431

Simultaneous observations of Schumann resonances in California and Australia: Evidence for intensity modulation by the local height of the D region  

SciTech Connect (OSTI)

Observations are presented of the horizontal magnetic component of Schumann resonance intensities as simultaneously measured at locations in California and Western Australia during two separate intervals September 2-17, 1989, and April 14-21, 1990. For both intervals, diurnal variations of the average magnetic power over the lowest three modes of the Schumann resonances showed substantially different temporal profiles at the California and Western Australia stations, with interstation correlations of 0.51 and 0.39, respectively. A method is demonstrated for determining from these observations the average local time variation of the height of the D region. A height variation is obtained that is nearly identical for the respective analysis intervals, with a minimum height occurring at approximately 1300-1400 LT and a maximum-to-minimum height difference of roughly 50% of the mean. When corrected for the local D region height, the detailed diurnal intensity profiles over the analysis intervals display a greatly improved similarity, with interstation correlation coefficients increasing from 0.51 to 0.70 and from 0.39 to 0.82, respectively. Substantial agreement between the two stations after correction for D region height suggest that such observations could be used to monitor the global totality and variability of lightning, quantitatively and at time resolutions of the order of 10 min or less, in studies of global change.

Sentman, D.D. (Univ. of California, Los Angeles (United States)); Fraser, B.J. (Univ. of Newcastle, New South Wales (Australia))

1991-09-01T23:59:59.000Z

432

A satellite ocean color observation operator system for eutrophication assessment in coastal waters  

E-Print Network [OSTI]

Group (IOCCG) and following their recent guidelines, novel in- herent optical properties approaches (e of model variables into observed quantities which simplifies the transport of measurement errors- chemical products (including

Fontana, Clément

433

Observed Feedback between Winter Sea Ice and the North Atlantic Oscillation  

E-Print Network [OSTI]

variability and climate feedbacks in a global coupled model.Ocean JOURNAL OF CLIMATE feedback on the North Atlantic2009 STRONG ET AL. Observed Feedback between Winter Sea Ice

Strong, Courtenay; Magnusdottir, Gudrun; Stern, Hal

2009-01-01T23:59:59.000Z

434

VARIABLE WINDS AND DUST FORMATION IN R CORONAE BOREALIS STARS  

SciTech Connect (OSTI)

We have observed P-Cygni and asymmetric, blue-shifted absorption profiles in the He I {lambda}10830 lines of 12 R Coronae Borealis stars over short (1 month) and long (3 yr) timescales to look for variations linked to their dust-formation episodes. In almost all cases, the strengths and terminal velocities of the line vary significantly and are correlated with dust formation events. Strong absorption features with blue-shifted velocities {approx}400 km s{sup -1} appear during declines in visible brightness and persist for about 100 days after recovery to maximum brightness. Small residual winds of somewhat lower velocity are present outside of the decline and recovery periods. The correlations support models in which recently formed dust near the star is propelled outward at high speed by radiation pressure and drags the gas along with it.

Clayton, Geoffrey C.; Zhang Wanshu [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Geballe, T. R., E-mail: gclayton@fenway.phys.lsu.edu, E-mail: wzhan21@lsu.edu, E-mail: tgeballe@gemini.edu [Gemini Observatory, 670 N. A'ohoku Place, Hilo, HI 96720 (United States)

2013-08-01T23:59:59.000Z

435

Longwave thermal infrared spectral variability in individual rocks  

SciTech Connect (OSTI)

A hyperspectral imaging spectrometer measuring in the longwave thermal infrared (7.6-11.6 {micro}m) with a spatial resolution less than 4 mm was used in the field to observe the variability of emissivity spectra within individual rocks. The rocks were obtained commercially, were on the order of 20 cm in size and were selected to have distinct spectral features: they include alabaster (gypsum), soapstone (steatite with talc), obsidian (volcanic glass), norite (plagioclase and orthopyroxene), and 'jasper' (silica with iron oxides). The advantages of using an imaging spectrometer to spectrally characterize these rocks are apparent. Large spectral variations were observed within individual rocks that may be attributed to roughness, surface geometry, and compositional variation. Non-imaging spectrometers would normally miss these variations as would small samples used in laboratory measurements, spatially averaged spectra can miss the optimum spectra for identification materials and spatially localized components of the rock can be obscured.

Balick, Lee K [Los Alamos National Laboratory; Gillespie, Alan [UN. WASHINGTON; French, Andrew [USDA-ARS; Danilina, Iryna [UN. WASHINGTON

2008-01-01T23:59:59.000Z

436

Bayesian and maximum entropy methods for fusion diagnostic measurements with compact neutron spectrometers  

SciTech Connect (OSTI)

In applications of neutron spectrometry to fusion diagnostics, it is advantageous to use methods of data analysis which can extract information from the spectrum that is directly related to the parameters of interest that describe the plasma. We present here methods of data analysis which were developed with this goal in mind, and which were applied to spectrometric measurements made with an organic liquid scintillation detector (type NE213). In our approach, we combine Bayesian parameter estimation methods and unfolding methods based on the maximum entropy principle. This two-step method allows us to optimize the analysis of the data depending on the type of information that we want to extract from the measurements. To illustrate these methods, we analyze neutron measurements made at the PTB accelerator under controlled conditions, using accelerator-produced neutron beams. Although the methods have been chosen with a specific application in mind, they are general enough to be useful for many other types of measurements.

Reginatto, Marcel; Zimbal, Andreas [Physikalisch-Technische Bundesanstalt, 38116 Braunschweig (Germany)

2008-02-15T23:59:59.000Z

437

Maximum Achievable Control Technology for New Industrial Boilers (released in AEO2005)  

Reports and Publications (EIA)

As part of Clean Air Act 90 (CAAA90, the EPA on February 26, 2004, issued a final rulethe National Emission Standards for Hazardous Air Pollutants (NESHAP) to reduce emissions of hazardous air pollutants (HAPs) from industrial, commercial, and institutional boilers and process heaters. The rule requires industrial boilers and process heaters to meet limits on HAP emissions to comply with a Maximum Achievable Control Technology (MACT) floor level of control that is the minimum level such sources must meet to comply with the rule. The major HAPs to be reduced are hydrochloric acid, hydrofluoric acid, arsenic, beryllium, cadmium, and nickel. The EPA predicts that the boiler MACT rule will reduce those HAP emissions from existing sources by about 59,000 tons per year in 2005.

2005-01-01T23:59:59.000Z

438

Netest: A Tool to Measure the Maximum Burst Size, Available Bandwidth and Achievable Throughput  

SciTech Connect (OSTI)

Distinguishing available bandwidth and achievable throughput is essential for improving network applications' performance. Achievable throughput is the throughput considering a number of factors such as network protocol, host speed, network path, and TCP buffer space, where as available bandwidth only considers the network path. Without understanding this difference, trying to improve network applications' performance is like ''blind men feeling the elephant'' [4]. In this paper, we define and distinguish bandwidth and throughput, and debate which part of each is achievable and which is available. Also, we introduce and discuss a new concept - Maximum Burst Size that is crucial to the network performance and bandwidth sharing. A tool, netest, is introduced to help users to determine the available bandwidth, and provides information to achieve better throughput with fairness of sharing the available bandwidth, thus reducing misuse of the network.

Jin, Guojun; Tierney, Brian

2003-01-31T23:59:59.000Z

439

Detailed analysis of an endoreversible fuel cell : Maximum power and optimal operating temperature determination  

E-Print Network [OSTI]

Producing useful electrical work in consuming chemical energy, the fuel cell have to reject heat to its surrounding. However, as it occurs for any other type of engine, this thermal energy cannot be exchanged in an isothermal way in finite time through finite areas. As it was already done for various types of systems, we study the fuel cell within the finite time thermodynamics framework and define an endoreversible fuel cell. Considering different types of heat transfer laws, we obtain an optimal value of the operating temperature, corresponding to a maximum produced power. This analysis is a first step of a thermodynamical approach of design of thermal management devices, taking into account performances of the whole system.

A. Vaudrey; P. Baucour; F. Lanzetta; R. Glises

2010-08-30T23:59:59.000Z

440

Detailed analysis of an endoreversible fuel cell : Maximum power and optimal operating temperature determination  

E-Print Network [OSTI]

Producing useful electrical work in consuming chemical energy, the fuel cell have to reject heat to its surrounding. However, as it occurs for any other type of engine, this thermal energy cannot be exchanged in an isothermal way in finite time through finite areas. As it was already done for various types of systems, we study the fuel cell within the finite time thermodynamics framework and define an endoreversible fuel cell. Considering different types of heat transfer laws, we obtain an optimal value of the operating temperature, corresponding to a maximum produced power. This analysis is a first step of a thermodynamical approach of design of thermal management devices, taking into account performances of the whole system.

Vaudrey, A; Lanzetta, F; Glises, R

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Combustion Process in a Spark Ignition Engine: Analysis of Cyclic Maximum Pressure and Peak Pressure Angle  

E-Print Network [OSTI]

In this paper we analyze the cycle-to-cycle variations of maximum pressure $p_{max}$ and peak pressure angle $\\alpha_{pmax}$ in a four-cylinder spark ignition engine. We examine the experimental time series of $p_{max}$ and $\\alpha_{pmax}$ for three different spark advance angles. Using standard statistical techniques such as return maps and histograms we show that depending on the spark advance angle, there are significant differences in the fluctuations of $p_{max}$ and $\\alpha_{pmax}$. We also calculate the multiscale entropy of the various time series to estimate the effect of randomness in these fluctuations. Finally, we explain how the information on both $p_{max}$ and $\\alpha_{pmax}$ can be used to develop optimal strategies for controlling the combustion process and improving engine performance.

G. Litak; T. Kaminski; J. Czarnigowski; A. K. Sen; M. Wendeker

2006-11-29T23:59:59.000Z

442

Azimuthal Anisotropy in Heavy Ion Collisions from the Maximum Entropy Method  

E-Print Network [OSTI]

We investigate the azimuthal anisotropy v2 of particle production in nucleus-nucleus collisions in the maximum entropy approach. This necessitates two new parameters delta and lambda2. The parameter delta describes the deformation of transverse configuration space and is related to the anisotropy of the overlap zone of the two nuclei. The parameter lambda2 defines the anisotropy of the particle distribution in momentum space. Assuming deformed flux tubes at the early stage of the collision we relate the momentum to the space asymmetry i.e. lambda2 to delta with the uncertainty relation. We compute the anisotropy v2 as a function of centrality, transverse momentum and rapidity using gluon-hadron duality. The general features of LHC data are reproduced.

Pirner, Hans J

2014-01-01T23:59:59.000Z

443

Source Function Determined from HBT Correlations by the Maximum Entropy Principle  

E-Print Network [OSTI]

We study the reconstruction of the source function in space-time directly from the measured HBT correlation function using the Maximum Entropy Principle. We find that the problem is ill-defined without at least one additional theoretical constraint as input. Using the requirement of a finite source lifetime for the latter we find a new Gaussian parametrization of the source function directly in terms of the measured HBT radius parameters and its lifetime, where the latter is a free parameter which is not directly measurable by HBT. We discuss the implications of our results for the remaining freedom in building source models consistent with a given set of measured HBT radius parameters.

Wu Yuanfang; Ulrich Heinz

1996-07-18T23:59:59.000Z

444

A maximum-entropy approach to the adiabatic freezing of a supercooled liquid  

E-Print Network [OSTI]

I employ the van der Waals theory of Baus and coworkers to analyze the fast, adiabatic decay of a supercooled liquid in a closed vessel with which the solidification process usually starts. By imposing a further constraint on either the system volume or pressure, I use the maximum-entropy method to quantify the fraction of liquid that is transformed into solid as a function of undercooling and of the amount of a foreign gas that could possibly be also present in the test tube. Upon looking at the implications of thermal and mechanical insulation for the energy cost of forming a solid droplet within the liquid, I identify one situation where the onset of solidification inevitably occurs near the wall in contact with the bath.

Santi Prestipino

2013-04-29T23:59:59.000Z

445

Lyapunov exponent and natural invariant density determination of chaotic maps: An iterative maximum entropy ansatz  

E-Print Network [OSTI]

We apply the maximum entropy principle to construct the natural invariant density and Lyapunov exponent of one-dimensional chaotic maps. Using a novel function reconstruction technique that is based on the solution of Hausdorff moment problem via maximizing Shannon entropy, we estimate the invariant density and the Lyapunov exponent of nonlinear maps in one-dimension from a knowledge of finite number of moments. The accuracy and the stability of the algorithm are illustrated by comparing our results to a number of nonlinear maps for which the exact analytical results are available. Furthermore, we also consider a very complex example for which no exact analytical result for invariant density is available. A comparison of our results to those available in the literature is also discussed.

Parthapratim Biswas; H. Shimoyama; L. R. Mead

2009-10-23T23:59:59.000Z

446

Spectral function and excited states in lattice QCD with maximum entropy method  

E-Print Network [OSTI]

We apply the maximum entropy method to extract the spectral functions for pseudoscalar and vector mesons from hadron correlators previously calculated at four different lattice spacings in quenched QCD with the Wilson quark action. We determine masses and decay constants for the ground and excited states of the pseudoscalar and vector channels from position and area of peaks in the spectral functions. We obtain the results, $m_{\\pi_1} = 660(590)$ MeV and $m_{\\rho_1} = 1540(570)$ MeV for the masses of the first excited state masses, in the continuum limit of quenched QCD. We also find unphysical states which have infinite mass in the continuum limit, and argue that they are bound states of two doublers of the Wilson quark action. If the interpretation is correct, this is the first time that the state of doublers is identified in lattice QCD numerical simulations.

CP-PACS Collaboration; :; T. Yamazaki; S. Aoki; R. Burkhalter; M. Fukugita; S. Hashimoto; N. Ishizuka; Y. Iwasaki; K. Kanaya; T. Kaneko; Y. Kuramashi; M. Okawa; Y. Taniguchi; A. Ukawa; T. Yoshi

2001-05-29T23:59:59.000Z

447

Azimuthal Anisotropy in Heavy Ion Collisions from the Maximum Entropy Method  

E-Print Network [OSTI]

We investigate the azimuthal anisotropy v2 of particle production in nucleus-nucleus collisions in the maximum entropy approach. This necessitates two new parameters delta and lambda2. The parameter delta describes the deformation of transverse configuration space and is related to the anisotropy of the overlap zone of the two nuclei. The parameter lambda2 defines the anisotropy of the particle distribution in momentum space. Assuming deformed flux tubes at the early stage of the collision we relate the momentum to the space asymmetry i.e. lambda2 to delta with the uncertainty relation. We compute the anisotropy v2 as a function of centrality, transverse momentum and rapidity using gluon-hadron duality. The general features of LHC data are reproduced.

Hans J. Pirner

2014-05-09T23:59:59.000Z

448

CP$^{N-1}$ model with the theta term and maximum entropy method  

E-Print Network [OSTI]

A $\\theta$ term in lattice field theory causes the sign problem in Monte Carlo simulations. This problem can be circumvented by Fourier-transforming the topological charge distribution $P(Q)$. This strategy, however, has a limitation, because errors of $P(Q)$ prevent one from calculating the partition function ${\\cal Z}(\\theta)$ properly for large volumes. This is called flattening. As an alternative approach to the Fourier method, we utilize the maximum entropy method (MEM) to calculate ${\\cal Z}(\\theta)$. We apply the MEM to Monte Carlo data of the CP$^3$ model. It is found that in the non-flattening case, the result of the MEM agrees with that of the Fourier transform, while in the flattening case, the MEM gives smooth ${\\cal Z}(\\theta)$.

Masahiro Imachi; Yasuhiko Shinno; Hiroshi Yoneyama

2004-09-25T23:59:59.000Z

449

MADmap: A Massively Parallel Maximum-Likelihood Cosmic Microwave Background Map-Maker  

SciTech Connect (OSTI)

MADmap is a software application used to produce maximum-likelihood images of the sky from time-ordered data which include correlated noise, such as those gathered by Cosmic Microwave Background (CMB) experiments. It works efficiently on platforms ranging from small workstations to the most massively parallel supercomputers. Map-making is a critical step in the analysis of all CMB data sets, and the maximum-likelihood approach is the most accurate and widely applicable algorithm; however, it is a computationally challenging task. This challenge will only increase with the next generation of ground-based, balloon-borne and satellite CMB polarization experiments. The faintness of the B-mode signal that these experiments seek to measure requires them to gather enormous data sets. MADmap is already being run on up to O(1011) time samples, O(108) pixels and O(104) cores, with ongoing work to scale to the next generation of data sets and supercomputers. We describe MADmap's algorithm based around a preconditioned conjugate gradient solver, fast Fourier transforms and sparse matrix operations. We highlight MADmap's ability to address problems typically encountered in the analysis of realistic CMB data sets and describe its application to simulations of the Planck and EBEX experiments. The massively parallel and distributed implementation is detailed and scaling complexities are given for the resources required. MADmap is capable of analysing the largest data sets now being collected on computing resources currently available, and we argue that, given Moore's Law, MADmap will be capable of reducing the most massive projected data sets.

Cantalupo, Christopher; Borrill, Julian; Jaffe, Andrew; Kisner, Theodore; Stompor, Radoslaw

2009-06-09T23:59:59.000Z

450

Is the friction angle the maximum slope of a free surface of a non cohesive material?  

E-Print Network [OSTI]

Starting from a symmetric triangular pile with a horizontal basis and rotating the basis in the vertical plane, we have determined the evolution of the stress distribution as a function of the basis inclination using Finite Elements method with an elastic-perfectly plastic constitutive model, defined by its friction angle, without cohesion. It is found that when the yield function is the Drucker-Prager one, stress distribution satisfying equilibrium can be found even when one of the free-surface slopes is larger than the friction angle. This means that piles with a slope larger than the friction angle can be (at least) marginally stable and that slope rotation is not always a destabilising perturbation direction. On the contrary, it is found that the slope cannot overpass the friction angle when a Mohr-Coulomb yield function is used. Theoretical explanation of these facts is given which enlightens the role plaid by the intermediate principal stress in both cases of the Mohr-Coulomb criterion and of the Drucker-Prager one. It is then argued that the Mohr-Coulomb criterion assumes a spontaneous symmetry breaking, as soon as the two smallest principal stresses are different ; this is not physical most likely; so this criterion shall be replaced by a Drucker-Prager criterion in the vicinity of the equality, which leads to the previous anomalous behaviour ; so these numerical computations enlighten the avalanche process: they show that no dynamical angle larger than the static one is needed to understand avalanching. It is in agreement with previous experimental results. Furthermore, these results show that the maximum angle of repose can be modified using cyclic rotations; we propose a procedure that allows to achieve a maximum angle of repose to be equal to the friction angle .

A. Modaressi; P. Evesque

2005-07-13T23:59:59.000Z

451

THE RR LYRAE VARIABLES AND HORIZONTAL BRANCH OF NGC 6656 (M22) {sup ,}  

SciTech Connect (OSTI)

The first calibrated broadband UBVI time-series photometry is presented for the RR Lyrae variable stars in NGC 6656 (M22), with observations spanning a range of 22 years. We have also redetermined the variability types and periods for the RR Lyrae stars identified previously by photographic observations, revising the number of fundamental-mode RR Lyrae variables (RR0) to 10 and the number of first-overtone variables (RR1) to 16. The mean periods of the RR0 and RR1 variables are (P) {sub RR0} = 0.66 0.02 days and (P) {sub RR1} = 0.33 0.01 days, respectively, supporting an Oosterhoff II classification for the cluster. The number ratio of RR1-type to all RR-type variables is N {sub 1}/N{sub RR} = 0.61, also consistent with an Oosterhoff II designation. Both the RR Lyrae stars' minimum light colors and the blue edge of the RR Lyrae instability strip suggest E( B V) = 0.36 0.02 mag toward M22. Regarding the HB morphology of M22, we find (B-R)/(B+V+R) = +0.97 0.1 and at least one ''gap'' located in an unusual part of the blue HB, in the middle of the so-called hot HB stars.

Kunder, Andrea; Walker, Alistair R.; Paredes Alvarez, Leonardo [Cerro Tololo Inter-American Observatory, Casilla 603, La Serena (Chile); Stetson, Peter B. [Dominion Astrophysical Observatory, NRC-Herzberg, National Research Council, Victoria BC, V9E 2E7 (Canada); Cassisi, Santi [INAF-Osservatorio Astronomico di Collurania, Via M. Maggini, I-64100 Teramo (Italy); Layden, Andrew [Bowling Green State University, Bowling Green, OH 43403 (United States); Bono, Giuseppe [Dipartimento di Fisica, Universita di Roma Tor Vergata, Rome (Italy); Catelan, Mrcio [Pontificia Universidad Catlica de Chile, Departamento de Astronoma y Astrofsica, Av. Vicua Mackenna 4860, 782-0436 Macul, Santiago (Chile); Clem, James L. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803-4001 (United States); Matsunaga, Noriyuki [Department of Astronomy, School of Science, The University of Tokyo (Japan); Salaris, Maurizio [Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Egerton Wharf, Birkenhead CH41 1LD (United Kingdom); Lee, Jae-Woo [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Chaboyer, Brian, E-mail: akunder@ctio.noao.edu, E-mail: mcatelan@astro.puc.cl [Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States)

2013-11-01T23:59:59.000Z

452

Observing alternatives to inflation  

E-Print Network [OSTI]

We discuss the possibility that the inflationary paradigm, undoubtfully today's best framework to understand all the present cosmological data, may still have some viable challengers. The underlying idea for such discussions is that although inflation already passed quite a large number of tests, indeed enough to make it part of the so-called ``standard model'' of cosmology, it has always been through indirect measurements: there is not a chance that we may ever directly check its validity, and therefore, in order to assert its factuality with increasing level of confidence, it is required that we compare its predictions not only to observations, but also to as many contenders as possible. Among other categories of possible models, we wish to put the emphasis in particular on bouncing cosmologies that, however not as complete as the inflation paradigm might be, could still represent a reasonnable way of explaining the current data. Hopefully, future data will be able to discriminate between these various sets of theories.

P. Peter

2009-12-07T23:59:59.000Z

453

Cloud speed impact on solar variability scaling ?? Application to the wavelet variability model  

E-Print Network [OSTI]

Kleissl, J. , 2013. Deriving cloud velocity from an array ofCloud Speed Impact on Solar Variability Scaling -this work, we determine from cloud speeds. Cloud simulator

Lave, Matthew; Kleissl, Jan

2013-01-01T23:59:59.000Z

454

Interannual variability of Caribbean rainfall, ENSO and the Atlantic Ocean  

E-Print Network [OSTI]

Interannual variability of Caribbean rainfall, ENSO and the Atlantic Ocean Alessandra Giannini variability of Caribbean-Central Americanrainfall are examined. The atmosphericcirculation over this region- ature (SST) variability associated with Caribbean rainfall, as selected by canonical correlation

Columbia University

455

On the practice of dichotomization of quantitative variables  

E-Print Network [OSTI]

The authors examine the practice of dichotomization of quantitative measures, wherein relationships among variables are examined after 1 or more variables have been converted to dichotomous variables by splitting the sample ...

MacCallum, R. C.; Zhang, S.; Preacher, K. J.; Rucker, D. D.

2002-01-01T23:59:59.000Z

456

Software Enabled Virtually Variable Displacement Pumps -Theoretical and Experimental Studies  

E-Print Network [OSTI]

Software Enabled Virtually Variable Displacement Pumps - Theoretical and Experimental Studies the functional equivalent of a variable displacement pump. This approach combines a fixed displacement pump valve control, without many of the shortcomings of commercially available variable displacement pumps

Li, Perry Y.

457

The use of 'race' as a variable in biomedical research  

E-Print Network [OSTI]

be used as a variable in biomedical research but mainly toRace as a Variable in Biomedical Research A dissertationRace as a Variable in Biomedical Research. Manifest,

Efstathiou, Sophia

2009-01-01T23:59:59.000Z

458

Indirectly sensing accelerator beam currents for limiting maximum beam current magnitude  

DOE Patents [OSTI]

A beam current limiter is disclosed for sensing and limiting the beam current in a particle accelerator, such as a cyclotron or linear accelerator, used in scientific research and medical treatment. A pair of independently operable capacitive electrodes sense the passage of charged particle bunches to develop an RF signal indicative of the beam current magnitude produced at the output of a bunched beam accelerator. The RF signal produced by each sensing electrode is converted to a variable DC voltage indicative of the beam current magnitude. The variable DC voltages thus developed are compared to each other to verify proper system function and are further compared to known references to detect beam currents in excess of pre-established limits. In the event of a system malfunction, or if the detected beam current exceeds pre-established limits, the beam current limiter automatically inhibits further accelerator operation. A high Q tank circuit associated with each sensing electrode provides a narrow system bandwidth to reduce noise and enhance dynamic range. System linearity is provided by injecting, into each sensing electrode, an RF signal that is offset from the bunching frequency by a pre-determined beat frequency to ensure that subsequent rectifying diodes operate in a linear response region. The system thus provides a large dynamic range in combination with good linearity. 6 figs.

Bogaty, J.M.; Clifft, B.E.; Bollinger, L.M.

1995-08-08T23:59:59.000Z

459

Statistical Analysis and Time Series Models for Minimum/Maximum Temperatures  

E-Print Network [OSTI]

temperatures, thereby reducing the adverse effect of global warming in the Antarctic Peninsula. Keywords that the observed increase in the minimum temperatures is a consequence of human activity rather than natural causes

Sidorov, Nikita

460

KINKS AND DENTS IN PROTOPLANETARY DISKS: RAPID INFRARED VARIABILITY AS EVIDENCE FOR LARGE STRUCTURAL PERTURBATIONS  

SciTech Connect (OSTI)

We report on synoptic observations at 3.6 and 4.5 {mu}m of young stellar objects in IC 348 with 38 epochs covering 40 days. We find that among the detected cluster members, 338 at [3.6] and 269 at both [3.6] and [4.5], many are variable on daily to weekly timescales with typical fluctuations of {approx}0.1 mag. The fraction of variables ranges from 20% for the diskless pre-main sequence stars to 60% for the stars still surrounded by infalling envelopes. We also find that stars in the exposed cluster core are less variable than the stars in the dense, slightly younger, southwestern ridge. This trend persists even after accounting for the underlying correlation with infrared spectral energy distribution type, suggesting that the change in variable fraction is not simply a reflection of the change in relative fraction of class I versus class II sources across the cloud, but instead reflects a change in variability with age. We also see a strong correlation between infrared variability and X-ray luminosity among the class II sources. The observed variability most likely reflects large changes in the structure of the inner wall located at the dust sublimation radius. We explore the possibility that these structural perturbations could be caused by a hot spot on the star heating dust above the sublimation temperature, causing it to evaporate rapidly, and increasing the inner radius for a portion of the disk. Under a number of simplifying assumptions we show that this model can reproduce the size and timescale of the 3.6 and 4.5 {mu}m fluctuations. Regardless of its source, the infrared variability indicates that the inner disk is not a slowly evolving entity, but instead is a bubbling, warped, dented mass of gas and dust whose global size and shape fluctuate in a matter of days.

Flaherty, K. M.; Rieke, G. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Muzerolle, J. [Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States); Gutermuth, R. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Balog, Z. [Max-Planck Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); Herbst, W. [Department of Astronomy, Wesleyan University, Middletown, CT 06459 (United States); Megeath, S. T., E-mail: kflaherty@as.arizona.edu [Department of Physics and Astronomy, University of Toledo, Toledo, OH (United States)

2013-03-15T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Compact, electro-hydraulic, variable valve actuation system providing...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Compact, electro-hydraulic, variable valve actuation system providing variable lift, timing and duration to enable high efficiency engine combustion control Compact,...

462

Sources of Technical Variability in Quantitative LC-MS Proteomics...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Sources of Technical Variability in Quantitative LC-MS Proteomics: Human Brain Tissue Sample Analysis. Sources of Technical Variability in Quantitative LC-MS Proteomics: Human...

463

Variable Speed Pumping: A Guide to Successful Applications -...  

Broader source: Energy.gov (indexed) [DOE]

Variable Speed Pumping: A Guide to Successful Applications - Executive Summary Variable Speed Pumping: A Guide to Successful Applications - Executive Summary This document...

464

Adaptation to Climate Variability and Change: A Guidance Manual...  

Open Energy Info (EERE)

to Climate Variability and Change: A Guidance Manual for Development Planning Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Adaptation to Climate Variability and...

465

Microstructural Response of Variably Hydrated Ca-Rich Montmorillonite...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Microstructural Response of Variably Hydrated Ca-Rich Montmorillonite to Supercritical CO2. Microstructural Response of Variably Hydrated Ca-Rich Montmorillonite to Supercritical...

466

Advanced Variable Speed Air-Source Integrated Heat Pump 2013...  

Energy Savers [EERE]

Advanced Variable Speed Air-Source Integrated Heat Pump 2013 Peer Review Advanced Variable Speed Air-Source Integrated Heat Pump 2013 Peer Review Emerging Technologies Project for...

467

Demonstration of a Variable Phase Turbine Power System for Low...  

Broader source: Energy.gov (indexed) [DOE]

Demonstration of a Variable Phase Turbine Power System for Low Temperature Geothermal Resources Demonstration of a Variable Phase Turbine Power System for Low Temperature...

468

Control Strategies for Centrifugal Pumps with Variable Flow Rate...  

Broader source: Energy.gov (indexed) [DOE]

Control Strategies for Centrifugal Pumps with Variable Flow Rate Requirements Control Strategies for Centrifugal Pumps with Variable Flow Rate Requirements This tip sheet discusses...

469

Two-Stage Variable Compression Ratio (VCR) System to Increase...  

Broader source: Energy.gov (indexed) [DOE]

Two-Stage Variable Compression Ratio (VCR) System to Increase Efficiency in Gasoline Powertrains Two-Stage Variable Compression Ratio (VCR) System to Increase Efficiency in...

470

Variable speed operation of generators with rotor-speed feedback in wind power applications  

SciTech Connect (OSTI)

The use of induction generators in wind power applications has been common since the early development of the wind industry. Most of these generators operate at fixed frequency and are connected directly to the utility grid. Unfortunately, this mode of operation limits the rotor speed to a specific rpm. Variable-speed operation is preferred in order to facilitate maximum energy capture over a wide range of wind speeds. This paper explores variable-speed operating strategies for wind turbine applications. The objectives are to maximize energy production, provide controlled start-up and reduce torque loading. This paper focuses on optimizing the energy captured by operating at maximum aerodynamic efficiency at any wind speed. The control strategy we analyze uses rotor speed and generator power as the feedback signals. In the normal operating region, rotor speed is used to compute a target power that corresponds to optimum operation. With power as the control objective, the power converter and generator are controlled to track the target power at any rpm. Thus, the torque-speed characteristic of the generator is shaped to optimize the energy capture. The target power is continuously updated at any rpm. in extreme areas of the operating envelope, during start-up, shutdown, generator overload, or overspeed, different strategies driven by other system considerations must be used.

Muljadi, E.; Butterfield, C.P.; Migliore, P.

1995-11-01T23:59:59.000Z

471

Variable speed operation of generators with rotor-speed feedback in wind power applications  

SciTech Connect (OSTI)

The use of induction generators in wind power applications has been common since the early development of the wind industry. Most of these generators operate at fixed frequency and are connected directly to the utility grid. Unfortunately, this mode of operation limits the rotor speed to a specific rpm. Variable-speed operation is preferred in order to facilitate maximum energy capture over a wide range of wind speeds. This paper explores variable-speed operating strategies for wind turbine applications. The objectives are to maximize energy production, provide controlled start-up and reduce torque loading. This paper focuses on optimizing the energy captured by operating at maximum aerodynamic efficiency at any wind speed. The control strategy analyzed uses rotor speed and generator power as the feedback signals. In the normal operating region, rotor speed is used to compute a target power that corresponds to optimum operation. With power as the control objective, the power converter and generator are controlled to track the target power at any rpm. Thus, the torque-speed characteristic of the generator is shaped to optimize the energy capture. The target power is continuously updated at any rpm. In extreme areas of the operating envelope, during start-up, shutdown, generator overload, or overspeed, different strategies driven by other system considerations must be used.

Muljadi, E.; Butterfield, C.P.; Migliore, P. [National Renewable Energy Lab., Golden, CO (United States). Wind Technology Div.

1996-10-01T23:59:59.000Z

472

Variable speed operation of generators with rotor-speed feedback in wind power applications  

SciTech Connect (OSTI)

The use of induction generators in wind power applications has been common since the early development of the wind industry. Most of these generators operate at fixed frequency and are connected directly to the utility grid. Unfortunately, this mode of operation limits the rotor speed to a specific rpm. Variable speed operation is preferred in order to facilitate maximum energy capture over a wide range of wind speeds. This paper explores variable speed operating strategies for wind turbine applications. The objectives are to maximize energy production, provide controlled start-up, and reduce torque loading. This paper focuses on optimizing the energy captured by operating at maximum aerodynamic efficiency at any wind speed. The control strategy the authors analyze uses rotor speed and generator power as the feedback signals. In the normal operating region, rotor speed is used to compute a target power that corresponds to optimum operation. With power as the control objective, the power converter and generator are controlled to track the target power at any rpm. Thus, the torque-speed characteristic of the generator is shaped to optimize the energy capture. The target power is continuously updated at any rpm. In extreme areas of the operating envelope, during start-up, shutdown, generator overload, or overspeed, different strategies driven by other system considerations must be used.

Muljadi, E.; Butterfield, C.P.; Migliore, P. [National Renewable Energy Lab., Golden, CO (United States)

1996-11-01T23:59:59.000Z

473

Measuring spatial variability in soil characteristics  

DOE Patents [OSTI]

The present invention provides systems and methods for measuring a load force associated with pulling a farm implement through soil that is used to generate a spatially variable map that represents the spatial variability of the physical characteristics of the soil. An instrumented hitch pin configured to measure a load force is provided that measures the load force generated by a farm implement when the farm implement is connected with a tractor and pulled through or across soil. Each time a load force is measured, a global positioning system identifies the location of the measurement. This data is stored and analyzed to generate a spatially variable map of the soil. This map is representative of the physical characteristics of the soil, which are inferred from the magnitude of the load force.

Hoskinson, Reed L. (Rigby, ID); Svoboda, John M. (Idaho Falls, ID); Sawyer, J. Wayne (Hampton, VA); Hess, John R. (Ashton, ID); Hess, J. Richard (Idaho Falls, ID)

2002-01-01T23:59:59.000Z

474

Variable energy constant current accelerator structure  

DOE Patents [OSTI]

A variable energy, constant current ion beam accelerator structure is disclosed comprising an ion source capable of providing the desired ions, a pre-accelerator for establishing an initial energy level, a matching/pumping module having means for focusing means for maintaining the beam current, and at least one main accelerator module for continuing beam focus, with means capable of variably imparting acceleration to the beam so that a constant beam output current is maintained independent of the variable output energy. In a preferred embodiment, quadrupole electrodes are provided in both the matching/pumping module and the one or more accelerator modules, and are formed using four opposing cylinder electrodes which extend parallel to the beam axis and are spaced around the beam at 90/degree/ intervals with opposing electrodes maintained at the same potential. 12 figs., 3 tabs.

Anderson, O.A.

1988-07-13T23:59:59.000Z

475

Infrared Properties of Cataclysmic Variables from 2MASS Results from the 2nd Incremental Data Release  

E-Print Network [OSTI]

Because accretion-generated luminosity dominates the radiated energy of most cataclysmic variables, they have been ``traditionally'' observed primarily at short wavelengths. Infrared observations of cataclysmic variables contribute to the understanding of key system components that are expected to radiate at these wavelengths, such as the cool outer disk, accretion stream, and secondary star. We have compiled the J, H, and Ks photometry of all cataclysmic variables located in the sky coverage of the 2 Micron All Sky Survey (2MASS) 2nd Incremental Data Release. This data comprises 251 systems with reliably identified near-IR counterparts and S/N > 10 photometry in one or more of the three near-IR bands.

Hoard, D W; Clark, L L; Bowers, T P; Bowers, Timothy P.

2001-01-01T23:59:59.000Z

476

Integrating Variable Renewable Energy: Challenges and Solutions  

SciTech Connect (OSTI)

In the U.S., a number of utilities are adopting higher penetrations of renewables, driven in part by state policies. While power systems have been designed to handle the variable nature of loads, the additional supply-side variability and uncertainty can pose new challenges for utilities and system operators. However, a variety of operational and technical solutions exist to help integrate higher penetrations of wind and solar generation. This paper explores renewable energy integration challenges and mitigation strategies that have been implemented in the U.S. and internationally, including forecasting, demand response, flexible generation, larger balancing areas or balancing area cooperation, and operational practices such as fast scheduling and dispatch.

Bird, L.; Milligan, M.; Lew, D.

2013-09-01T23:59:59.000Z

477

Variable pressure power cycle and control system  

DOE Patents [OSTI]

A variable pressure power cycle and control system that is adjustable to a variable heat source is disclosed. The power cycle adjusts itself to the heat source so that a minimal temperature difference is maintained between the heat source fluid and the power cycle working fluid, thereby substantially matching the thermodynamic envelope of the power cycle to the thermodynamic envelope of the heat source. Adjustments are made by sensing the inlet temperature of the heat source fluid and then setting a superheated vapor temperature and pressure to achieve a minimum temperature difference between the heat source fluid and the working fluid.

Goldsberry, Fred L. (Spring, TX)

1984-11-27T23:59:59.000Z

478

A new variable in flow analysis  

E-Print Network [OSTI]

We have used a simple spectrum distribution which was derived from a hydrodynamical equation\\cite{Csorgo} to fit the data of the STAR group. It is found that it can fit the $v_2$ of STAR group very well. We have found that $v_2$ is sensitive to both the effective temperature of particles and the expanding velocity. We have suggested a new variable ${\\bf z}$ to be used in the flow analysis. This new variable will measure the correlation of particles momentum components. We have also shown that one of the $x$ or $y$ direction in the reaction plane is the direction which has the largest variance.

Q. H. Zhang; L. Huo; W. N. Zhang

2006-06-20T23:59:59.000Z

479

INTERANNUAL VARIABILITY IN GLOBAL SOIL RESPIRATION (1980-1994) Interannual Variability in Global Soil  

E-Print Network [OSTI]

INTERANNUAL VARIABILITY IN GLOBAL SOIL RESPIRATION (1980-1994) NDP-081 Interannual Variability in Global Soil Respiration on a 0.5 Degree Grid Cell Basis (1980-1994) Contributed by: James W. Raich 1, Tennessee 37831-6335. The ORNL is managed by UT-Battelle, LLC for the U.S. DEPARTMENT OF ENERGY under

480

X-ray Observations of Mrk 231  

E-Print Network [OSTI]

This paper presents new X-ray observations of Mrk 231, an active galaxy of particular interest due to its large infrared luminosity and the presence of several blueshifted broad absorption line (BAL) systems, a phenomenon observed in a small fraction of QSOs. A ROSAT HRI image of Mrk 231 is presented, this shows an extended region of soft X-ray emission, covering several tens of kpc, consistent with the extent of the host galaxy. An ASCA observation of Mrk 231 is also presented. Hard X-rays are detected but the data show no significant variability in X-ray flux. The hard X-ray continuum is heavily attenuated and X-ray column estimates range from ~ 2 x 10^{22} - 10^{23} cm^{-2} depending on whether the material is assumed to be neutral or ionized, and on the model assumed for the extended X-ray component. These ASCA data provide only the second hard X-ray spectrum of a BAL AGN presented to date. The broad-band spectral-energy-distribution of the source is discussed. While Mrk 231 is X-ray weak compared to Seyfert 1 galaxies, it has an optical-to-X-ray spectrum typical of a QSO.

T. J. Turner

1998-08-10T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Investigating Broadband Variability of the TeV Blazar 1ES 1959+650  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

We summarize broadband observations of the TeV-emitting blazar 1ES 1959 650, including optical R-band observations by the robotic telescopes Super-LOTIS and iTelescope, UV observations by Swift Ultraviolet and Optical Telescope, X-ray observations by the Swift X-ray Telescope, high-energy gamma-ray observations with the Fermi Large Area Telescope, and very-high-energy (VHE) gamma-ray observations by VERITAS above 315 GeV, all taken between 2012 April 17 and 2012 June 1 (MJD 56034 and 56079). The contemporaneous variability of the broadband spectral energy distribution is explored in the context of a simple synchrotron self Compton (SSC) model. In the SSC emission scenario, we find that the parameters required to represent the high state are significantly different than those in the low state. Motivated by possible evidence of gas in the vicinity of the blazar, we also investigate a reflected emission model to describe the observed variability pattern. This model assumes that the non-thermal emission from the jet is reflected by a nearby cloud of gas, allowing the reflected emission to re-enter the blob and produce an elevated gamma-ray state with no simultaneous elevated synchrotron flux. The model applied here, although not required to explain the observed variability pattern, represents one possible scenario which can describe the observations. As applied to an elevated VHE state of 66% of the Crab Nebula flux, observed on a single night during the observation period, the reflected emission scenario does not support a purely leptonic non-thermal emission mechanism. The r

Aliu, E.; Archambault, S.; Arlen, T.; Aune, T.; Barnacka, A.; Beilicke, M.; Benbow, W.; Berger, K.; Bird, R.; Bouvier, A.; Buckley, J. H.; Bugaev, V.; Cerruti, M.; Chen, X.; Ciupik, L.; Collins-Hughes, E.; Connolly, M. P.; Cui, W.; Dumm, J.; Eisch, J. D.; Falcone, A.

2015-01-06T23:59:59.000Z

482

Investigating Broadband Variability of the TeV Blazar 1ES 1959+650  

SciTech Connect (OSTI)

We summarize broadband observations of the TeV-emitting blazar 1ES 1959 650, including optical R-band observations by the robotic telescopes Super-LOTIS and iTelescope, UV observations by Swift Ultraviolet and Optical Telescope, X-ray observations by the Swift X-ray Telescope, high-energy gamma-ray observations with the Fermi Large Area Telescope, and very-high-energy (VHE) gamma-ray observations by VERITAS above 315 GeV, all taken between 2012 April 17 and 2012 June 1 (MJD 56034 and 56079). The contemporaneous variability of the broadband spectral energy distribution is explored in the context of a simple synchrotron self Compton (SSC) model. In the SSC emission scenario, we find that the parameters required to represent the high state are significantly different than those in the low state. Motivated by possible evidence of gas in the vicinity of the blazar, we also investigate a reflected emission model to describe the observed variability pattern. This model assumes that the non-thermal emission from the jet is reflected by a nearby cloud of gas, allowing the reflected emission to re-enter the blob and produce an elevated gamma-ray state with no simultaneous elevated synchrotron flux. The model applied here, although not required to explain the observed variability pattern, represents one possible scenario which can describe the observations. As applied to an elevated VHE state of 66% of the Crab Nebula flux, observed on a single night during the observation period, the reflected emission scenario does not support a purely leptonic non-thermal emission mechanism. The reflected model does, however, predict a reflected photon field with sufficient energy to enable elevated gamma-ray emission via pion production with protons of energies between 10 and 100 TeV.

Aliu, E. [Columbia Univ., NY (United States). Barnard College; Archambault, S. [McGill Univ., Montreal, Quebec (Canada); Arlen, T. [Univ. of California, Los Angeles, CA (United States); Aune, T. [Univ. of California, Los Angeles, CA (United States); Barnacka, A. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Beilicke, M. [Washington Univ., St. Louis, MO (United States); Benbow, W.; Berger, K.; Bird, R.; Bouvier, A.; Buckley, J. H. [Washington Univ., St. Louis, MO (United States); Bugaev, V.; Cerruti, M.; Chen, X.; Ciupik, L.; Collins-Hughes, E.; Connolly, M. P.; Cui, W.; Dumm, J.; Eisch, J. D.; Falcone, A.; Federici, S.; Feng, Q.; Finley, J. P.; Fleischhack, H.; Hanna, D.; Holder, J.; Hughes, G.; Hughes, Z.; Humensky, T. B.; Johnson, C. A.; Kaaret, P.; Kar, P.; Kertzman, M.; Khassen, Y.; Kieda, D.; Krawczynski, H.; Krennrich, F.; Lang, M. J.; Madhavan, A. S.; Majumdar, P.; McArthur, S.; McCann, A.; Meagher, K.; Millis, J.; Moriarty, P.; Mukherjee, R.; Nelson, T.; Nieto, D.; O'Faolain de Bhroithe, A.; Ong, R. A.; Otte, A. N.; Park, N.; Perkins, J. S.; Pohl, M.; Popkow, A.; Prokoph, H.; Quinn, J.; Ragan, K.; Rajotte, J.; Reyes, L. C.; Reynolds, P. T.; Richards, G. T.; Roache, E.; Sadun, A.; Santander, M.; Sembroski, G. H.; Shahinyan, K.; Sheidaei, F.; Smith, A. W.; Staszak, D.; Telezhinsky, I.; Theiling, M.; Tyler, J.; Varlotta, A.; Vassiliev, V. V.; Vincent, S.; Wakeley, S. P.; Weekes, T. C.; Weinstein, A.; Welsing, R.; Wilhelm, A.; Williams, D. A.; Zitzer, B.; Boettcher, M. [North-West University, Centre for Space Research, Potchefstroom (South Africa); Fumagalli, M. [Carnegie Observatories, Pasadena, CA (United States); Princeton Univ., NJ (United States)

2014-12-03T23:59:59.000Z

483

Greenland Ice Sheet Surface Air Temperature Variability: 18402007* JASON E. BOX  

E-Print Network [OSTI]

Greenland Ice Sheet Surface Air Temperature Variability: 18402007* JASON E. BOX Byrd Polar, seasonal, and annual mean Greenland ice sheet near- surface air temperatures. Independent observations Greenland in autumn and southern Greenland in winter. Spring trends marked the 1920s warming onset, while

Howat, Ian M.

484

Model simulation of Greenland Sea upper-ocean variability S. Hakkinen,1  

E-Print Network [OSTI]

Model simulation of Greenland Sea upper-ocean variability S. Hakkinen,1 F. Dupont,2 M. Karcher,3-ocean water masses coincides with periods of intense deep-water formation in the Greenland Sea. This paper-ocean properties observed in the Greenland Sea, including very dense, saline water masses in the 1950s, 1960s

Zhang, Jinlun

485

Remote Sensing of Mobile Source Air Pollutant Emissions: Variability and Uncertainty in On-Road Emissions  

E-Print Network [OSTI]

Remote Sensing of Mobile Source Air Pollutant Emissions: Variability and Uncertainty in On.0 INTRODUCTION 1 1.1 Mobile Source Emissions 2 1.2 Emission Regulations 2 1.3 Emissions Contributions of "Non Estimates 70 6.3 Fuel Economy Data for School Buses Observed at the Rock Quarry Road Site 75 6.4 Diesel

Frey, H. Christopher

486

Effect of the Young modulus variability on the mechanical behaviour of a nuclear containment vessel  

E-Print Network [OSTI]

Effect of the Young modulus variability on the mechanical behaviour of a nuclear containment vessel on the mechanical behaviour of a nuclear containment vessel in case of a loss of cooling agent accident and under values are observed. Preprint submitted to Nuclear Engineering and Design April 19, 2010 hal-00542640

487

Using Feedforward Neural Networks and Forward Selection of Input Variables for an Ergonomics Data  

E-Print Network [OSTI]

Using Feedforward Neural Networks and Forward Selection of Input Variables for an Ergonomics Data-gradient algorithm to develop an FNN. This article presents an incremental step in the use of FNNs for ergonomics enhancing the effectiveness of the use of neural networks when observations are missing from ergonomics

Kaber, David B.

488

Parametric study on maximum transportable distance and cost for thermal energy transportation using various coolants  

SciTech Connect (OSTI)

The operation temperature of advanced nuclear reactors is generally higher than commercial light water reactors and thermal energy from advanced nuclear reactor can be used for various purposes such as district heating, desalination, hydrogen production and other process heat applications, etc. The process heat industry/facilities will be located outside the nuclear island due to safety measures. This thermal energy from the reactor has to be transported a fair distance. In this study, analytical analysis was conducted to identify the maximum distance that thermal energy could be transported using various coolants such as molten-salts, helium and water by varying the pipe diameter and mass flow rate. The cost required to transport each coolant was also analyzed. The coolants analyzed are molten salts (such as: KClMgCl2, LiF-NaF-KF (FLiNaK) and KF-ZrF4), helium and water. Fluoride salts are superior because of better heat transport characteristics but chloride salts are most economical for higher temperature transportation purposes. For lower temperature water is a possible alternative when compared with He, because low pressure He requires higher pumping power which makes the process very inefficient and economically not viable for both low and high temperature application.

Su-Jong Yoon; Piyush Sabharwall

2014-07-01T23:59:59.000Z

489

Maximum Reasonable Radioxenon Releases from Medical Isotope Production Facilities and Their Effect on Monitoring Nuclear Explosions  

SciTech Connect (OSTI)

Fission gases such as 133Xe are used extensively for monitoring the world for signs of nuclear testing in systems such as the International Monitoring System (IMS). These gases are also produced by nuclear reactors and by fission production of 99Mo for medical use. Recently, medical isotope production facilities have been identified as the major contributor to the background of radioactive xenon isotopes (radioxenon) in the atmosphere (Saey, et al., 2009). These releases pose a potential future problem for monitoring nuclear explosions if not addressed. As a starting point, a maximum acceptable daily xenon emission rate was calculated, that is both scientifically defendable as not adversely affecting the IMS, but also consistent with what is possible to achieve in an operational environment. This study concludes that an emission of 5109 Bq/day from a medical isotope production facility would be both an acceptable upper limit from the perspective of minimal impact to monitoring stations, but also appears to be an achievable limit for large isotope producers.

Bowyer, Ted W. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Kephart, Rosara F.; Eslinger, Paul W. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Friese, Judah I. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Miley, Harry S. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Saey, Paul R. [Vienna University of Technology, Atomic Institute of the Austrian Universities, Vienna (Austria)

2013-01-01T23:59:59.000Z

490

Thermal modification of bottomonium spectra from QCD sum rules with the maximum entropy method  

E-Print Network [OSTI]

The bottomonium spectral functions at finite temperature are analyzed by employing QCD sum rules with the maximum entropy method. This approach enables us to extract the spectral functions without any phenomenological parametrization, and thus to visualize deformation of the spectral functions due to temperature effects estimated from quenched lattice QCD data. As a result, it is found that \\Upsilon and \\eta_b survive in hot matter of temperature up to at least 2.3T_c and 2.1T_c, respectively, while \\chi_{b0} and \\chi_{b1} will disappear at T<2.5T_c. Furthermore, a detailed analysis of the vector channel shows that the spectral function in the region of the lowest peak at T=0 contains contributions from the excited states, \\Upsilon(2S) and \\Upsilon(3S), as well as the ground states \\Upsilon (1S). Our results at finite T are consistent with the picture that the excited states of bottomonia dissociate at lower temperature than that of the ground state. Assuming this picture, we find that \\Upsilon(2S) and \\Upsilon(3S) disappear at T=1.5-2.0T_c.

Kei Suzuki; Philipp Gubler; Kenji Morita; Makoto Oka

2012-12-03T23:59:59.000Z

491

Linearized semiclassical initial value time correlation functions with maximum entropy analytic continuation  

SciTech Connect (OSTI)

The maximum entropy analytic continuation (MEAC) method is used to extend the range of accuracy of the linearized semiclassical initial value representation (LSC-IVR)/classical Wigner approximation for real time correlation functions. The LSC-IVR provides a very effective 'prior' for the MEAC procedure since it is very good for short times, exact for all time and temperature for harmonic potentials (even for correlation functions of nonlinear operators), and becomes exact in the classical high temperature limit. This combined MEAC+LSC/IVR approach is applied here to two highly nonlinear dynamical systems, a pure quartic potential in one dimensional and liquid para-hydrogen at two thermal state points (25K and 14K under nearly zero external pressure). The former example shows the MEAC procedure to be a very significant enhancement of the LSC-IVR, for correlation functions of both linear and nonlinear operators, and especially at low temperature where semiclassical approximations are least accurate. For liquid para-hydrogen, the LSC-IVR is seen already to be excellent at T = 25K, but the MEAC procedure produces a significant correction at the lower temperature (T = 14K). Comparisons are also made to how the MEAC procedure is able to provide corrections for other trajectory-based dynamical approximations when used as priors.

Liu, Jian; Miller, William H.

2008-08-01T23:59:59.000Z

492

BONA FIDE, STRONG-VARIABLE GALACTIC LUMINOUS BLUE VARIABLE STARS ARE FAST ROTATORS: DETECTION OF A HIGH ROTATIONAL VELOCITY IN HR CARINAE  

SciTech Connect (OSTI)

We report optical observations of the luminous blue variable (LBV) HR Carinae which show that the star has reached a visual minimum phase in 2009. More importantly, we detected absorptions due to Si IV lambdalambda4088-4116. To match their observed line profiles from 2009 May, a high rotational velocity of v{sub rot} approx = 150 +- 20 km s{sup -1} is needed (assuming an inclination angle of 30 deg.), implying that HR Car rotates at approx =0.88 +- 0.2 of its critical velocity for breakup (v{sub crit}). Our results suggest that fast rotation is typical in all strong-variable, bona fide galactic LBVs, which present S-Dor-type variability. Strong-variable LBVs are located in a well-defined region of the HR diagram during visual minimum (the 'LBV minimum instability strip'). We suggest this region corresponds to where v{sub crit} is reached. To the left of this strip, a forbidden zone with v{sub rot}/v{sub crit}>1 is present, explaining why no LBVs are detected in this zone. Since dormant/ex LBVs like P Cygni and HD 168625 have low v{sub rot}, we propose that LBVs can be separated into two groups: fast-rotating, strong-variable stars showing S-Dor cycles (such as AG Car and HR Car) and slow-rotating stars with much less variability (such as P Cygni and HD 168625). We speculate that supernova (SN) progenitors which had S-Dor cycles before exploding (such as in SN 2001ig, SN 2003bg, and SN 2005gj) could have been fast rotators. We suggest that the potential difficulty of fast-rotating Galactic LBVs to lose angular momentum is additional evidence that such stars could explode during the LBV phase.

Groh, J. H. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany); Damineli, A.; Moises, A. P.; Teodoro, M. [Instituto de Astronomia, Geofisica e Ciencias Atmosfericas, Universidade de Sao Paulo, Rua do Matao 1226, Cidade Universitaria, 05508-090, Sao Paulo, SP (Brazil); Hillier, D. J. [Department of Physics and Astronomy, University of Pittsburgh, 3941 O'Hara Street, Pittsburgh, PA 15260 (United States); Barba, R. [Departamento de fisica, Universidad de La Serena, Benavente 980, La Serena (Chile); Fernandez-Lajus, E.; Gamen, R. C.; Solivella, G., E-mail: jgroh@mpifr-bonn.mpg.d [Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, and Instituto de Astrofisica de La Plata (CCT La Plata-CONICET), Paseo del Bosque S/N, B1900FWA, La Plata (Argentina)

2009-11-01T23:59:59.000Z

493

Heart Rate Variability Malvin Carl Teich  

E-Print Network [OSTI]

Heart Rate Variability Malvin Carl Teich Boston University and Columbia University http, Grasmere, UK, 2005 #12;CONGESTIVE HEART FAILURE INABILITY OF HEART TO INCREASE CARDIAC OUTPUT IN PROPORTION of breath Swelling in legs General fatigue and weakness Clinical diagnostics: Ascultate heart Carotid pulse

Teich, Malvin C.

494

Hydrologically Sensitive Areas: Variable Source Area Hydrology  

E-Print Network [OSTI]

Hydrologically Sensitive Areas: Variable Source Area Hydrology Implications for Water Quality Risk hydrology was developed and applied to the New York City (NYC) water supply watersheds. According and are therefore hydrologically sensitive with respect to their potential to transport contaminants to perennial

Walter, M.Todd

495

The Sun is an active, variable,  

E-Print Network [OSTI]

The Sun is an active, variable, magnetic star with oscillations on its surface and deep within its the physical processes of the Sun-Earth connection. Visit Us on the Web: Solar Terrestrial Probes Program: http://stp.gsfc.nasa.gov For More Information, See: Sun-Earth Connection: http://sec.gsfc.nasa.gov Living With a Star: http

Christian, Eric

496

Chapter 18: Variable Frequency Drive Evaluation Protocol  

SciTech Connect (OSTI)

An adjustable-speed drive (ASD) includes all devices that vary the speed of a rotating load, including those that vary the motor speed and linkage devices that allow constant motor speed while varying the load speed. The Variable Frequency Drive Evaluation Protocol presented here addresses evaluation issues for variable-frequency drives (VFDs) installed on commercial and industrial motor-driven centrifugal fans and pumps for which torque varies with speed. Constant torque load applications, such as those for positive displacement pumps, are not covered by this protocol. Other ASD devices, such as magnetic drive, eddy current drives, variable belt sheave drives, or direct current motor variable voltage drives, are also not addressed. The VFD is by far the most common type of ASD hardware. With VFD speed control on a centrifugal fan or pump motor, energy use follows the affinity laws, which state that the motor electricity demand is a cubic relationship to speed under ideal conditions. Therefore, if the motor runs at 75% speed, the motor demand will ideally be reduced to 42% of full load power; however, with other losses it is about 49% of full load power.

Romberger, J.

2014-11-01T23:59:59.000Z

497

Markovian feedback to control continuous variable entanglement  

E-Print Network [OSTI]

We present a model to realize quantum feedback control of continuous variable entanglement. It consists of two interacting bosonic modes subject to amplitude damping and achieving entangled Gaussian steady state. The possibility to greatly improve the degree of entanglement by means of Markovian (direct) feedback is then shown.

Stefano Mancini

2005-04-18T23:59:59.000Z

498

Variable Light-Cone Theory of Gravity  

E-Print Network [OSTI]

We show how to reformulate Variable Speed of Light Theories (VSLT) in a covariant fashion as Variable Light-Cone Theories (VLCT) by introducing two vierbein bundles each associated with a distinct metric. The basic gravitational action relates to one bundle while matter propagates relative to the other in a conventional way. The variability of the speed of light is represented by the variability of the matter light-cone relative to the gravitational light-cone. The two bundles are related locally by an element M, of SL(4,R). The dynamics of the field M is that of a SL(4,R)-sigma model gauged with respect to local (orthochronous) Lorentz transformations on each of the bundles. Only the ``massless'' version of the model with a single new coupling, F, that has the same dimensions as Newton's constant $G_N$, is considered in this paper. When F vanishes the theory reduces to standard General Relativity. We verify that the modified Bianchi identities of the model are consistent with the standard conservation law for the matter energy-momentum tensor in its own background metric. The implications of the model for some simple applications are examined, the Newtonian limit, the flat FRW universe and the spherically symmetric static solution.

I. T. Drummond

1999-08-20T23:59:59.000Z

499

An Exploratory Study of Variability in Safety  

E-Print Network [OSTI]

An Exploratory Study of Variability in Safety Culture among Clinician types and Patient Care of the current study was to (a) examine how different types of care providers viewed the safety culture of their unit, and (b) examine the relationship between hospital safety culture and patient satisfaction

von der Heydt, Rüdiger

500

Original article Variability of digestibility criteria  

E-Print Network [OSTI]

Original article Variability of digestibility criteria in maize elite hybrids submitted of various in vitro digestibility criteria used to estimate genotypic variation in silage maize elite hybrids and in vitro digestibility of whole-plant and cell-walls were pre- dicted by near infra-red reflectance

Boyer, Edmond