Sample records for maximum variable observations

  1. Belief space planning assuming maximum likelihood observations

    E-Print Network [OSTI]

    Lozano-Perez, Tomas

    observations are modelled as Gaussian noise. Given this model of the dynamics, two planning and control methods-locating the sensors with the contacts this way complicates planning and control because it forces the system to trade of the partially observable control problem, often modeled as a partially observable Markov decision process (POMDP

  2. Tropical climate variability from the last glacial maximum to the present

    E-Print Network [OSTI]

    Dahl, Kristina Ariel

    2005-01-01T23:59:59.000Z

    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 ...

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

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -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

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

    E-Print Network [OSTI]

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

    2015-01-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

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

    1997-04-14T23:59:59.000Z

    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.

  6. 8) Stratospheric equatorial variability a) Observations

    E-Print Network [OSTI]

    Lott, Francois

    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

  7. OBSERVATIONS OF THERMAL FLARE PLASMA WITH THE EUV VARIABILITY EXPERIMENT

    SciTech Connect (OSTI)

    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

    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.

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

    SciTech Connect (OSTI)

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

    2012-01-01T23:59:59.000Z

    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.

  9. Have Aerosols Caused the Observed Atlantic Multidecadal Variability?

    E-Print Network [OSTI]

    Zhang, Rong

    Identifying the prime drivers of the twentieth-century multidecadal variability in the Atlantic Ocean is crucial for predicting how the Atlantic will evolve in the coming decades and the resulting broad impacts on weather ...

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

    E-Print Network [OSTI]

    L. Albano Farias; J. Stephany

    2010-09-28T23:59:59.000Z

    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.

  11. Observer Variability in Metameric Color Matches using Color

    E-Print Network [OSTI]

    Fairchild, Mark D.

    * 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

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

    E-Print Network [OSTI]

    R. Smith; S. Vaughan

    2007-01-08T23:59:59.000Z

    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.

  13. PRECISE HIGH-CADENCE TIME SERIES OBSERVATIONS OF FIVE VARIABLE YOUNG STARS IN AURIGA WITH MOST

    SciTech Connect (OSTI)

    Cody, Ann Marie; Tayar, Jamie; Hillenbrand, Lynne A. [Department of Astrophysics, California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States); Matthews, Jaymie M. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1 (Canada); Kallinger, Thomas, E-mail: amc@ipac.caltech.edu [Institut fuer Astronomie, Universitaet Wien, Tuerkenschanzstrasse 17, A-1180 Vienna (Austria)

    2013-03-15T23:59:59.000Z

    To explore young star variability on a large range of timescales, we have used the MOST satellite to obtain 24 days of continuous, sub-minute cadence, high-precision optical photometry on a field of classical and weak-lined T Tauri stars (TTSs) in the Taurus-Auriga star formation complex. Observations of AB Aurigae, SU Aurigae, V396 Aurigae, V397 Aurigae, and HD 31305 reveal brightness fluctuations at the 1%-10% level on timescales of hours to weeks. We have further assessed the variability properties with Fourier, wavelet, and autocorrelation techniques, identifying one significant period per star. We present spot models in an attempt to fit the periodicities, but find that we cannot fully account for the observed variability. Rather, all stars exhibit a mixture of periodic and aperiodic behavior, with the latter dominating stochastically on timescales less than several days. After removal of the main periodicity, periodograms for each light curve display power-law trends consistent with those seen for other young accreting stars. Several of our targets exhibited unusual variability patterns not anticipated by prior studies, and we propose that this behavior originates with the circumstellar disks. The MOST observations underscore the need for investigation of TTS light variations on a wide range of timescales in order to elucidate the physical processes responsible; we provide guidelines for future time series observations.

  14. Observed low frequency variability of the Brazil Current front Gustavo Jorge Goni,1

    E-Print Network [OSTI]

    of the Brazil Current front. Trends of eddy kinetic energy, sea height anomaly, sea surface temperature and windObserved low frequency variability of the Brazil Current front Gustavo Jorge Goni,1 Francis Bringas; published 29 October 2011. [1] The Brazil Current is a weak western boundary current, the southwest

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

    E-Print Network [OSTI]

    Gruben, David Christopher

    1987-01-01T23:59:59.000Z

    , 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...

  16. New Variable Stars Discovered by the APACHE Survey. II. Results After the Second Observing Season

    E-Print Network [OSTI]

    Damasso, M; Bernagozzi, A; Bertolini, E; Calcidese, P; Carbognani, A; Cenadelli, D; Christille, J M; Giacobbe, P; Lanteri, L; Smart, M G Lattanzi R; Sozzetti, A

    2015-01-01T23:59:59.000Z

    Routinely operating since July 2012, the APACHE survey has celebrated its second birthday. While the main goal of the Project is the detection of transiting planets around a large sample of bright, nearby M dwarfs in the northern hemisphere, the APACHE large photometric database for hundreds of different fields represents a relevant resource to search for and provide a first characterization of new variable stars. We celebrate here the conclusion of the second year of observations by reporting the discovery of 14 new variables.

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

    E-Print Network [OSTI]

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

    1995-10-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    I. A. Smith; E. P. Liang

    1998-12-08T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    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

    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.

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

    E-Print Network [OSTI]

    Xie, Shang-Ping

    ; 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

  1. The response of glaciers to intrinsic climate variability: observations and models of late-Holocene variations in the

    E-Print Network [OSTI]

    Roe, Gerard

    The response of glaciers to intrinsic climate variability: observations and models of late glacier variations due to natural climate variability and those due to true climate change is crucial for the interpretation and attribution of past glacier changes, and for the expectations of future changes. We explore

  2. Nature of the Mesoscale Boundary Layer Height and Water Vapor Variability Observed 14 June 2002 during the IHOP_2002 Campaign

    E-Print Network [OSTI]

    Guichard, Francoise

    Nature of the Mesoscale Boundary Layer Height and Water Vapor Variability Observed 14 June 2002, Boulder, Colorado (Manuscript received 4 September 2007, in final form 23 June 2008) ABSTRACT Mesoscale at the mesoscale, with the spatial pattern and the magnitude of the variability changing from day to day. On 14

  3. Variability in the Initial Costs of Care and One-Year Outcomes of Observation Services

    E-Print Network [OSTI]

    Abbass, Ibrahim

    2015-01-01T23:59:59.000Z

    Variability in the initial costs of care across theVariability in the Initial Costs of Care and One-Yearis associated with lower costs and comparable level of care

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

    E-Print Network [OSTI]

    Johnson, Richard H.

    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

  5. Observations of Antarctic Circumpolar Current dynamics in the Drake Passage and small-scale variability near the Antarctic Peninsula

    E-Print Network [OSTI]

    Lenn, Yueng Djern

    2006-01-01T23:59:59.000Z

    Mean Jets, Mesoscale Variability and Eddy Momentum Fluxes inlayer Mean Ve- locities and Mesoscale Variability in DrakeFiring, E. , 2006: Mean Jets, Mesoscale Variability and Eddy

  6. Observational Accuracy of Variable Stars, Novae and Supernovae from Naked Eye to General Relativistic Standard: a Balance over Thousand SGQ Observations Sent to AAVSO

    E-Print Network [OSTI]

    Sigismondi, Costantino

    2015-01-01T23:59:59.000Z

    The theory of General Relativity deals with very accurate measurements that show significant divergences from Newtonian predictions only with speeds near to the velocity of light. An introduction for educational purposes, based on naked eye photometry, deals with the radiation near collapsing star's shells like novae and supernovae. The theme of accuracy is drafted from entry level observations to the precision of professional data, often of public domain on the web. Thousand observations of variable stars, included the type 1a SN2014J, the Nova Del 2013 and the Nova Cen 2013, sent to the AAVSO by the author, with SGQ code, during the period 1998-2015 are analyzed to increase the photometric accuracy, in the occasion of the International Year of Light 2015.

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

    E-Print Network [OSTI]

    Radha, Hayder

    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

  8. Theory of fluorescence correlation spectroscopy at variable observation area for two-dimensional diffusion on a meshgrid

    E-Print Network [OSTI]

    Nicolas Destainville

    2007-11-29T23:59:59.000Z

    It has recently been proposed, with the help of numerical investigations, that fluorescence correlation spectroscopy at variable observation area can reveal the existence of a meshgrid of semi-permeable barriers hindering the two-dimensional diffusion of tagged particles, such as plasmic membrane constituents. We present a complete theory confirming and accounting for these findings. It enables a reliable, quantitative exploitation of experimental data from which the sub-wavelength mesh size can be extracted. Time scales at which fluorescence correlation spectroscopy must be performed experimentally are discussed in detail.

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

    SciTech Connect (OSTI)

    Bishop, James K.B.; Wood, Todd

    2009-02-01T23:59:59.000Z

    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.

  10. MELE: Maximum Entropy Leuven Estimators

    E-Print Network [OSTI]

    Paris, Quirino

    2001-01-01T23:59:59.000Z

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

  11. Maximum Parsimony and Maximum Likelihood Methods Comparisons and Bootstrap Tests

    E-Print Network [OSTI]

    Qiu, Weigang

    Maximum Parsimony and Maximum Likelihood Methods Comparisons and Bootstrap Tests Character Likelihood Methods Comparisons and Bootstrap Tests Character Reconstruction PHYLIP and T-REX Exercises Outline 1 Maximum Parsimony and Maximum Likelihood 2 Methods Comparisons and Bootstrap Tests 3 Character

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

    E-Print Network [OSTI]

    Michael Schubnell

    1997-07-11T23:59:59.000Z

    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.

  13. Maximum Entropy Correlated Equilibria

    E-Print Network [OSTI]

    Ortiz, Luis E.

    2006-03-20T23:59:59.000Z

    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 ...

  14. 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for RenewableSpeeding accessSpeeding access(SC)Gas and OilPhaseObservation of aof

  15. B and I-band optical micro-variability observations of the BL Lac objects S5 2007+777 and 3C371

    E-Print Network [OSTI]

    E. M. Xilouris; I. E. Papadakis; P. Boumis; A. Dapergolas; J. Alikakos; J. Papamastorakis; N. Smith; C. D. Goudis

    2005-11-04T23:59:59.000Z

    We have observed S5 2007+777 and 3C371 in the B and I bands for 13 and 8 nights, respectively, during various observing runs in 2001, 2002 and 2004. The observations resulted in almost evenly sampled light curves, 6-9 hours long. We do not detect any flares within the observed light curves, but we do observe small amplitude, significant variations, in both bands, on time scales of hours and days. The average variability amplitude on time scales of minutes/hours is 2.5% and 1-1.5% in the case of S5 2007+777 and 3C371, respectively. The average amplitudes increase to 5-12% and 4-6%, respectively, on time scales of days. We find that the B and I band variations are highly correlated, on both short and long time scales. During the 2004 observations, which resulted in the longest light curves, we observe two well defined flux-decay and rising trends in the light curves of both objects. When the flux decays, we observe significant delays, with the B band flux decaying faster than the flux in the I band. As a result, we also observe significant, flux related spectral variations as well. The flux-spectral relation is rather complicated, with loop-like structures forming during the flux evolution. The presence of spectral variations imply that the observed variability is not caused by geometric effects. On the other hand, our results are fully consistent with the hypothesis that the observed variations are caused by perturbations which affect different regions in the jet of the sources.

  16. Maximum Likelihood Haplotyping for General Pedigrees

    E-Print Network [OSTI]

    Friedman, Nir

    networks. The use of Bayesian networks enables efficient maximum likelihood haplotyping for more complex for the variables of the Bayesian network. The presented optimization algorithm also improves likelihood Analysis, Pedigree, superlink. Abstract Haplotype data is valuable in mapping disease-susceptibility genes

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

    E-Print Network [OSTI]

    Velicogna, I.; Wahr, J.

    2013-01-01T23:59:59.000Z

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

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

    E-Print Network [OSTI]

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

    2000-10-20T23:59:59.000Z

    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.

  19. university-logo Maximum likelihood

    E-Print Network [OSTI]

    McCullagh, Peter

    university-logo Maximum likelihood Applications and examples REML and residual likelihood Peter McCullagh REML #12;university-logo Maximum likelihood Applications and examples JAN: Some personal remarks... IC #12;university-logo Maximum likelihood Applications and examples Outline 1 Maximum likelihood REML

  20. Testing the inverse-Compton catastrophe scenario in the intra-day variable blazar S5 0716+71. I. Simultaneous broadband observations during November 2003

    E-Print Network [OSTI]

    L. Ostorero; S. J. Wagner; J. Gracia; E. Ferrero; T. P. Krichbaum; S. Britzen; A. Witzel; K. Nilsson; M. Villata

    2006-02-10T23:59:59.000Z

    Some intra-day variable, compact extra-galactic radio sources show brightness temperatures severely exceeding 10^{12} K, the limit set by catastrophic inverse-Compton (IC) cooling in sources of incoherent synchrotron radiation. The violation of the IC limit, possible under non-stationary conditions, would lead to IC avalanches in the soft-gamma-ray energy band during transient periods. For the first time, broadband signatures of possible IC catastrophes were searched for in S5 0716+71. A multifrequency observing campaign targetting S5 0716+71 was carried out in November 2003 under the framework of the European Network for the Investigation of Galactic nuclei through Multifrequency Analysis (ENIGMA) together with a campaign by the Whole Earth Blazar Telescope (WEBT), involving a pointing by the soft-gamma-ray satellite INTEGRAL, optical, near-infrared, sub-millimeter, millimeter, radio, and Very Long Baseline Array (VLBA) monitoring. S5 0716+71 was very bright at radio frequencies and in a rather faint optical state during the INTEGRAL pointing; significant inter-day and low intra-day variability was recorded in the radio regime, while typical fast variability features were observed in the optical band. No correlation was found between the radio and optical emission. The source was not detected by INTEGRAL, neither by the X-ray monitor JEM-X nor by the gamma-ray imager ISGRI, but upper limits to the source emission in the 3-200 keV energy band were estimated. A brightness temperature Tb>2.1x10^{14} K was inferred from the radio variability, but no corresponding signatures of IC avalanches were recorded at higher energies. The absence of IC-catastrophe signatures provides either a lower limit delta>8 to the Doppler factor affecting the radio emission or strong constraints for modelling of the Compton catastrophes in S5 0716+71.

  1. ROSAT/ASCA Observations of a Serendipitous BL Lac Object PKS 2316-423: The Variable High-Energy Tail of Synchrotron Radiation

    E-Print Network [OSTI]

    Sui-Jian Xue; You-Hong Zhang; Jian-Sheng Chen

    2000-05-22T23:59:59.000Z

    We present the analysis of archival data from ROSAT and ASCA of a serendipitous BL Lac object PKS 2316-423. Because of its featureless non-thermal radio/optical continuum, PKS 2316-423 has been called as a BL Lac candidate in the literature. PKS 2316-423 was evidently variable over the multiple X-ray observations, in particular, a variable high-energy tail of the synchrotron radiation is revealed. The X-ray spectral analysis provides further evidence of the synchrotron nature of its broad-band spectrum: a steep and downward curving spectrum between 0.1--10 keV, typical of high-energy peaked BL Lacs (HBL). The spectral energy distribution (SED) through radio-to-X-ray yields the synchrotron radiation peak at frequency Vp=7.3 10^{15} Hz, with integrated luminosity of Lsyn=2.1 10^{44} ergs s^{-1}. The averaged SED properties of PKS 2316-423 are very similar to those ``intermediate'' BL Lac objects (IBL) found recently in several deep surveys, such as Deep X-ray Radio Blazar, Radio-Emitting X-ray, and ROSAT-Green Bank surveys. We suggest that PKS 2316-423 is an IBL though it also shows some general features of a HBL. Actually, this double attribute of PKS 2316-423 provides a good test of the prediction that an IBL object can show either synchrotron or inverse-Compton characteristics in different variability states.

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

    E-Print Network [OSTI]

    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; González, M M; Goodman, J A; Hays, E; Hoffman, C M; Hüntemeyer, 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

    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...

  3. Intra-day variability observations of S5 0716+714 over 4.5 years at 4.8 GHz

    E-Print Network [OSTI]

    Liu, X; Marchili, N; Liu, B -R; Liu, J; Krichbaum, T P; Fuhrmann, L; Zensus, J A

    2012-01-01T23:59:59.000Z

    We aim to search for evidence of annual modulation in the time scales of the BL Lac object S5 0716+714. The intra-day variability (IDV) observations were carried out monthly from 2005 to 2009, with the Urumqi 25m radio telescope at 4.8 GHz. The source has shown prominent IDV as well as long-term flux variations. The IDV time scale does show evidence in favor of an annual modulation, suggesting that the IDV of 0716+714 is dominated by interstellar scintillation. The source underwent a strong outburst phase between mid-2008 and mid-2009; a second intense flare was observed in late 2009, but no correlation between the total flux density and the IDV time scale is found, implying that the flaring state of the source does not have serious implications for the general characteristics of its intra-day variability. However, we find that the inner-jet position angle is changing throughout the years, which could result in an annual modulation noise in the anisotropic ISS model fit. There is also an indication that the l...

  4. Achieve maximum application availability and

    E-Print Network [OSTI]

    Bernstein, Phil

    Highlights Achieve maximum application availability and data protection using SQL Server AlwaysOn and other high availability features Reduce planned downtime significantly with SQL Server on Windows and management of high availability and disaster recovery using integrated tools Achieve maximum application

  5. Original article Restricted maximum likelihood

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Original article Restricted maximum likelihood estimation of covariances in sparse linear models on the simplex algorithm of Nelder and Mead [40]. Kovac [29] made modifications that turned it into a stable

  6. Tissue Radiation Response with Maximum Tsallis Entropy

    SciTech Connect (OSTI)

    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

    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.

  7. Weak Scale From the Maximum Entropy Principle

    E-Print Network [OSTI]

    Yuta Hamada; Hikaru Kawai; Kiyoharu Kawana

    2014-09-23T23:59:59.000Z

    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}},\

  8. Weak Scale From the Maximum Entropy Principle

    E-Print Network [OSTI]

    Hamada, Yuta; Kawana, Kiyoharu

    2014-01-01T23:59:59.000Z

    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}},\

  9. Maximum power tracking control scheme for wind generator systems

    E-Print Network [OSTI]

    Mena Lopez, Hugo Eduardo

    2008-10-10T23:59:59.000Z

    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...

  10. Maximum power tracking control scheme for wind generator systems

    E-Print Network [OSTI]

    Mena, Hugo Eduardo

    2009-05-15T23:59:59.000Z

    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...

  11. Maximum power tracking control scheme for wind generator systems 

    E-Print Network [OSTI]

    Mena, Hugo Eduardo

    2009-05-15T23:59:59.000Z

    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...

  12. Maximum power tracking control scheme for wind generator systems 

    E-Print Network [OSTI]

    Mena Lopez, Hugo Eduardo

    2008-10-10T23:59:59.000Z

    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...

  13. Conductivity maximum in a charged colloidal suspension

    SciTech Connect (OSTI)

    Bastea, S

    2009-01-27T23:59:59.000Z

    Molecular dynamics simulations of a charged colloidal suspension in the salt-free regime show that the system exhibits an electrical conductivity maximum as a function of colloid charge. We attribute this behavior to two main competing effects: colloid effective charge saturation due to counterion 'condensation' and diffusion slowdown due to the relaxation effect. In agreement with previous observations, we also find that the effective transported charge is larger than the one determined by the Stern layer and suggest that it corresponds to the boundary fluid layer at the surface of the colloidal particles.

  14. Maximum likelihood estimation for cooperative sequential adsorption

    E-Print Network [OSTI]

    Burton, Geoffrey R.

    Maximum likelihood estimation for cooperative sequential adsorption Mathew D. Penrose and Vadim;Maximum likelihood estimation for cooperative sequential adsorption M.D. Penrose, Department of the region. Keywords: cooperative sequential adsorption, space-time point pro- cess, maximum likelihood

  15. Estimating a mixed strategy employing maximum entropy

    E-Print Network [OSTI]

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

    1996-01-01T23:59:59.000Z

    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

  16. Boiler Maximum Achievable Control Technology (MACT) Technical...

    Energy Savers [EERE]

    Boiler Maximum Achievable Control Technology (MACT) Technical Assistance - Fact Sheet, April 2015 Boiler Maximum Achievable Control Technology (MACT) Technical Assistance - Fact...

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

    E-Print Network [OSTI]

    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

    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...

  18. Max '91: flare research at the next solar maximum

    SciTech Connect (OSTI)

    Dennis, B.; Canfield, R.; Bruner, M.; Emslie, G.; Hildner, E.; Hudson, H.; Hurford, G.; Lin, R.; Novick, R.; Tarbell, T.

    1988-01-01T23:59:59.000Z

    To address the central scientific questions surrounding solar flares, coordinated observations of electromagnetic radiation and energetic particles must be made from spacecraft, balloons, rockets, and ground-based observatories. A program to enhance capabilities in these areas in preparation for the next solar maximum in 1991 is recommended. The major scientific issues are described, and required observations and coordination of observations and analyses are detailed. A program plan and conceptual budgets are provided.

  19. Maximum entropy principal for transportation

    SciTech Connect (OSTI)

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

    2008-11-06T23:59:59.000Z

    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.

  20. Renewable variable speed hybrid system 

    E-Print Network [OSTI]

    Stott, Paul Anthony

    2010-01-01T23:59:59.000Z

    generator island grids, these generators will be running at a fraction of maximum output for most of the time. A new variable speed diesel generator allows for a reduction in fuel consumption at part load compared to constant speed operation. Combining...

  1. Maximum-likelihood density modification

    SciTech Connect (OSTI)

    Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Structural Biology Group, Mail Stop M888, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2000-08-01T23:59:59.000Z

    A likelihood-based density modification approach is developed that can incorporate expected electron-density information from a wide variety of sources. A likelihood-based approach to density modification is developed that can be applied to a wide variety of cases where some information about the electron density at various points in the unit cell is available. The key to the approach consists of developing likelihood functions that represent the probability that a particular value of electron density is consistent with prior expectations for the electron density at that point in the unit cell. These likelihood functions are then combined with likelihood functions based on experimental observations and with others containing any prior knowledge about structure factors to form a combined likelihood function for each structure factor. A simple and general approach to maximizing the combined likelihood function is developed. It is found that this likelihood-based approach yields greater phase improvement in model and real test cases than either conventional solvent flattening and histogram matching or a recent reciprocal-space solvent-flattening procedure [Terwilliger (1999 ?), Acta Cryst. D55, 1863–1871].

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

    E-Print Network [OSTI]

    B. Fuchs

    1998-12-02T23:59:59.000Z

    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.

  3. When are microcircuits well-modeled by maximum entropy methods?

    E-Print Network [OSTI]

    2010-07-20T23:59:59.000Z

    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...

  4. Valence quark distributions of the proton from maximum entropy approach

    E-Print Network [OSTI]

    Rong Wang; Xurong Chen

    2014-10-14T23:59:59.000Z

    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.

  5. Valence quark distributions of the proton from maximum entropy approach

    E-Print Network [OSTI]

    Wang, Rong

    2014-01-01T23:59:59.000Z

    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.

  6. Optimization Online - Efficient Heuristic Algorithms for Maximum ...

    E-Print Network [OSTI]

    T. G. J. Myklebust

    2012-11-19T23:59:59.000Z

    Nov 19, 2012 ... Efficient Heuristic Algorithms for Maximum Utility Product Pricing Problems. T. G. J. Myklebust(tmyklebu ***at*** csclub.uwaterloo.ca)

  7. Maximum stellar mass versus cluster membership number revisited

    E-Print Network [OSTI]

    Th. Maschberger; C. J. Clarke

    2008-09-05T23:59:59.000Z

    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.

  8. Maximum entropy segmentation of broadcast news 

    E-Print Network [OSTI]

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

    2005-01-01T23:59:59.000Z

    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...

  9. Maximum entropy method for reconstruction of the CMB images

    E-Print Network [OSTI]

    A. T. Bajkova

    2002-05-21T23:59:59.000Z

    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.

  10. Higher Order Maximum Persistency and Comparison Theorems

    E-Print Network [OSTI]

    Alexander Shekhovtsov

    2014-10-15T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Osterloh, Frank

    Maximum Theoretical Efficiency Limit of Photovoltaic Devices: Effect of Band Structure on Excited a theoretical limit for the maximum energy conversion efficiency of single junction photovoltaic cells for the efficiency variations observed for real photovoltaic devices today.4-6 Here, we show that the extractable

  12. Cell development obeys maximum Fisher information

    E-Print Network [OSTI]

    B. R. Frieden; R. A. Gatenby

    2014-04-29T23:59:59.000Z

    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.

  13. Cataclysmic Variables

    E-Print Network [OSTI]

    Robert Connon Smith

    2007-01-23T23:59:59.000Z

    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.

  14. Interannual variability in tropospheric nitrous oxide

    E-Print Network [OSTI]

    Thompson, R. L.

    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 ...

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

    E-Print Network [OSTI]

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

    2015-01-01T23:59:59.000Z

    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...

  16. Integrating Correlated Bayesian Networks Using Maximum Entropy

    SciTech Connect (OSTI)

    Jarman, Kenneth D.; Whitney, Paul D.

    2011-08-30T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

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

    2008-07-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  19. QCD Level Density from Maximum Entropy Method

    E-Print Network [OSTI]

    Shinji Ejiri; Tetsuo Hatsuda

    2005-09-24T23:59:59.000Z

    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.

  20. A global maximum power point tracking DC-DC converter

    E-Print Network [OSTI]

    Duncan, Joseph, 1981-

    2005-01-01T23:59:59.000Z

    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 ...

  1. Maximum total organic carbon limit for DWPF melter feed

    SciTech Connect (OSTI)

    Choi, A.S.

    1995-03-13T23:59:59.000Z

    DWPF recently decided to control the potential flammability of melter off-gas by limiting the total carbon content in the melter feed and maintaining adequate conditions for combustion in the melter plenum. With this new strategy, all the LFL analyzers and associated interlocks and alarms were removed from both the primary and backup melter off-gas systems. Subsequently, D. Iverson of DWPF- T{ampersand}E requested that SRTC determine the maximum allowable total organic carbon (TOC) content in the melter feed which can be implemented as part of the Process Requirements for melter feed preparation (PR-S04). The maximum TOC limit thus determined in this study was about 24,000 ppm on an aqueous slurry basis. At the TOC levels below this, the peak concentration of combustible components in the quenched off-gas will not exceed 60 percent of the LFL during off-gas surges of magnitudes up to three times nominal, provided that the melter plenum temperature and the air purge rate to the BUFC are monitored and controlled above 650 degrees C and 220 lb/hr, respectively. Appropriate interlocks should discontinue the feeding when one or both of these conditions are not met. Both the magnitude and duration of an off-gas surge have a major impact on the maximum TOC limit, since they directly affect the melter plenum temperature and combustion. Although the data obtained during recent DWPF melter startup tests showed that the peak magnitude of a surge can be greater than three times nominal, the observed duration was considerably shorter, on the order of several seconds. The long surge duration assumed in this study has a greater impact on the plenum temperature than the peak magnitude, thus making the maximum TOC estimate conservative. Two models were used to make the necessary calculations to determine the TOC limit.

  2. 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...

  3. Variable Valve Actuation

    SciTech Connect (OSTI)

    Jeffrey Gutterman; A. J. Lasley

    2008-08-31T23:59:59.000Z

    Many approaches exist to enable advanced mode, low temperature combustion systems for diesel engines - such as premixed charge compression ignition (PCCI), Homogeneous Charge Compression Ignition (HCCI) or other HCCI-like combustion modes. The fuel properties and the quantity, distribution and temperature profile of air, fuel and residual fraction in the cylinder can have a marked effect on the heat release rate and combustion phasing. Figure 1 shows that a systems approach is required for HCCI-like combustion. While the exact requirements remain unclear (and will vary depending on fuel, engine size and application), some form of substantially variable valve actuation is a likely element in such a system. Variable valve actuation, for both intake and exhaust valve events, is a potent tool for controlling the parameters that are critical to HCCI-like combustion and expanding its operational range. Additionally, VVA can be used to optimize the combustion process as well as exhaust temperatures and impact the after treatment system requirements and its associated cost. Delphi Corporation has major manufacturing and product development and applied R&D expertise in the valve train area. Historical R&D experience includes the development of fully variable electro-hydraulic valve train on research engines as well as several generations of mechanical VVA for gasoline systems. This experience has enabled us to evaluate various implementations and determine the strengths and weaknesses of each. While a fully variable electro-hydraulic valve train system might be the 'ideal' solution technically for maximum flexibility in the timing and control of the valve events, its complexity, associated costs, and high power consumption make its implementation on low cost high volume applications unlikely. Conversely, a simple mechanical system might be a low cost solution but not deliver the flexibility required for HCCI operation. After modeling more than 200 variations of the mechanism it was determined that the single cam design did not have enough flexibility to satisfy three critical OEM requirements simultaneously, (maximum valve lift variation, intake valve opening timing and valve closing duration), and a new approach would be necessary. After numerous internal design reviews including several with the OEM a dual cam design was developed that had the flexibility to meet all motion requirements. The second cam added complexity to the mechanism however the cost was offset by the deletion of the electric motor required in the previous design. New patent applications including detailed drawings and potential valve motion profiles were generated and alternate two cam designs were proposed and evaluated for function, cost, reliability and durability. Hardware was designed and built and testing of sample hardware was successfully completed on an engine test stand. The mechanism developed during the course of this investigation can be applied by Original Equipment Manufacturers, (OEM), to their advanced diesel engines with the ultimate goal of reducing emissions and improving fuel economy. The objectives are: (1) Develop an optimal, cost effective, variable valve actuation (VVA) system for advanced low temperature diesel combustion processes. (2) Design and model alternative mechanical approaches and down-select for optimum design. (3) Build and demonstrate a mechanism capable of application on running engines.

  4. Observational learning in horses

    E-Print Network [OSTI]

    Baer, Katherine Louise

    1979-01-01T23:59:59.000Z

    . One group served as control subjects while the other group functioned as a treated group (observers). The observers were allowed to watch a correctly performed discrimination task prior to testing of a learning response using the same task.... Discrimination testing was conducted on all horses daily for 14 days with criterion set at seven out of eight responses correct with the last five consecutively correct. The maximum number of trials performed without reaching set criterion was limited...

  5. Maximum screening fields of superconducting multilayer structures

    E-Print Network [OSTI]

    Gurevich, Alex

    2015-01-01T23:59:59.000Z

    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.

  6. Maximum Entropy Method Approach to $?$ Term

    E-Print Network [OSTI]

    Masahiro Imachi; Yasuhiko Shinno; Hiroshi Yoneyama

    2004-06-09T23:59:59.000Z

    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.

  7. Maximum Throughput Power Control in CDMA Wireless Networks

    E-Print Network [OSTI]

    Mellor-Crummey, John

    Maximum Throughput Power Control in CDMA Wireless Networks Anastasios Giannoulis Department introduce cross­layer, distributed power control algorithms that guarantee maximum possible data throughput performing dynamic routing and scheduling together with power control. The cross­layer interaction consists

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

    E-Print Network [OSTI]

    Allan, Richard P.

    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

  9. GMM Estimation of a Maximum Entropy Distribution with Interval Data

    E-Print Network [OSTI]

    Perloff, Jeffrey M.

    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

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

    E-Print Network [OSTI]

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

    2006-03-03T23:59:59.000Z

    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.

  11. Department of Mathematics 4.2: The Simplex Method: Solving Maximum Problems in standard form by the simplex

    E-Print Network [OSTI]

    Ahmad, Sajjad

    UNLV Department of Mathematics §4.2: The Simplex Method: Solving Maximum Problems in standard form by the simplex method A. Simplex algorithm Once we have the problem in standard form(see 4.1) we are ready to perform the simplex operation according to the following algorithm: 1. Insert a slack variable into each

  12. Maximum gravitational-wave energy emissible in magnetar flares

    E-Print Network [OSTI]

    Alessandra Corsi; Benjamin J. Owen

    2011-02-16T23:59:59.000Z

    Recent searches of gravitational-wave (GW) data raise the question of what maximum GW energies could be emitted during gamma-ray flares of highly magnetized neutron stars (magnetars). The highest energies (\\sim 10^{49} erg) predicted so far come from a model [K. Ioka, Mon. Not. Roy. Astron. Soc. 327, 639 (2001)] in which the internal magnetic field of a magnetar experiences a global reconfiguration, changing the hydromagnetic equilibrium structure of the star and tapping the gravitational potential energy without changing the magnetic potential energy. The largest energies in this model assume very special conditions, including a large change in moment of inertia (which was observed in at most one flare), a very high internal magnetic field, and a very soft equation of state. Here we show that energies of 10^{48}-10^{49} erg are possible under more generic conditions by tapping the magnetic energy, and we note that similar energies may also be available through cracking of exotic solid cores. Current observational limits on gravitational waves from magnetar fundamental modes are just reaching these energies and will beat them in the era of advanced interferometers.

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

    E-Print Network [OSTI]

    Mandelis, Andreas

    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

  14. The Maximum Mass of a Neutron Star

    E-Print Network [OSTI]

    Vassiliki Kalogera; Gordon Baym

    1996-08-11T23:59:59.000Z

    Observational identification of black holes as members of binary systems requires the knowledge of the upper limit on the gravitational mass of a neutron star. We use modern equations of state for neutron star matter, fitted to experimental nucleon-nucleon scattering data and the properties of light nuclei, to calculate, within the framework of Rhoades & Ruffini (1974), the minimum upper limit on a neutron star mass. Regarding the equation of state as valid up to twice nuclear matter saturation density, rho_{nm}, we obtain a secure upper bound on the neutron star mass equal to 2.9 solar masses. We also find that in order to reach the lowest possible upper bound of 2.2 solar masses, we need understand the physical properties of neutron matter up to a density of about 4 times rho_{nm}.

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

    E-Print Network [OSTI]

    Amin Mobasher

    2005-10-03T23:59:59.000Z

    Oct 3, 2005 ... A Near Maximum Likelihood Decoding Algorithm for MIMO Systems Based ... models are also used for soft output decoding in MIMO systems.

  16. Computing the Maximum Volume Inscribed Ellipsoid of a Polytopic ...

    E-Print Network [OSTI]

    Jianzhe Zhen

    2015-01-23T23:59:59.000Z

    Jan 23, 2015 ... Abstract: This paper introduces a method for computing the maximum volume inscribed ellipsoid and k-ball of a projected polytope. It is known ...

  17. Solving Maximum-Entropy Sampling Problems Using Factored Masks

    E-Print Network [OSTI]

    Samuel Burer

    2005-03-02T23:59:59.000Z

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

  18. A masked spectral bound for maximum-entropy sampling

    E-Print Network [OSTI]

    Kurt Anstreicher

    2003-09-16T23:59:59.000Z

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

  19. Maximum entropy generation in open systems: the Fourth Law?

    E-Print Network [OSTI]

    Umberto Lucia

    2010-11-17T23:59:59.000Z

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

  20. annual maximum extent: Topics by E-print Network

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

    of the Sixteenth Annual Conference on Neural Information Processing Systems (NIPS2002) A Maximum Entropy Approach To Computer Technologies and Information Sciences Websites...

  1. 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...

  2. IBM Research Report Solving Maximum-Entropy Sampling ...

    E-Print Network [OSTI]

    2005-02-28T23:59:59.000Z

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

  3. 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...

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

    E-Print Network [OSTI]

    Fratantoni, David

    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

  5. 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

  6. FAST SPEAKER ADAPTION VIA MAXIMUM PENALIZED LIKELIHOOD KERNEL REGRESSION

    E-Print Network [OSTI]

    Tsang Wai Hung "Ivor"

    of MLLR using non- linear regression. Specifically, kernel regression is applied with appropriate of Science and Technology Clear Water Bay, Hong Kong ABSTRACT Maximum likelihood linear regression (MLLR) has], and transformation-based methods, most notably, maximum likelihood linear regression (MLLR) adap- tation [3]. However

  7. Digital tomosynthesis mammography using a parallel maximum likelihood reconstruction method

    E-Print Network [OSTI]

    Meleis, Waleed

    Digital tomosynthesis mammography using a parallel maximum likelihood reconstruction method Tao Wu , a Radiology Department, Massachusetts General Hospital, Boston, MA 02114 b Dept. of Electrical and Computer on an iterative maximum likelihood (ML) algorithm, is developed to provide fast reconstruction for digital

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

    SciTech Connect (OSTI)

    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

    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)

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

    E-Print Network [OSTI]

    Abe, Sumiyoshi

    2014-01-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Yegang Wu; S. Teitel

    2014-10-17T23:59:59.000Z

    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.

  11. 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...

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

    E-Print Network [OSTI]

    Liu, Jian

    2008-01-01T23:59:59.000Z

    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-

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

    E-Print Network [OSTI]

    Holzer, Mark; Primeau, Francois W

    2010-01-01T23:59:59.000Z

    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

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

    E-Print Network [OSTI]

    Soffer, Bernard H; Kikuchi, Ryoichi

    1994-01-01T23:59:59.000Z

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

  15. Solitary waves propagating over variable Roger Grimshaw

    E-Print Network [OSTI]

    Solitary waves propagating over variable topography Roger Grimshaw Loughborough University waves that can propagate steadily over long distances. They were first observed by Russell in 1837 in a now famous report [26] on his observations of a solitary wave propagating along a Scottish canal

  16. Ashtekar's variables without spin

    E-Print Network [OSTI]

    Thomas Schucker

    2009-06-26T23:59:59.000Z

    Ashtekar's variables are shown to arise naturally from a 3+1 split of general relativity in the Einstein-Cartan formulation. Thereby spinors are exorcised.

  17. Multichannel Blind Identification: From Subspace to Maximum Likelihood Methods

    E-Print Network [OSTI]

    Tong, Lang

    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

  18. Maximum containment : the most controversial labs in the world

    E-Print Network [OSTI]

    Bruzek, Alison K. (Allison Kim)

    2013-01-01T23:59:59.000Z

    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 ...

  19. On the maximum pressure rise rate in boosted HCCI operation

    E-Print Network [OSTI]

    Wildman, Craig B.

    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 ...

  20. Maximum Photovoltaic Penetration Levels on Typical Distribution Feeders: Preprint

    SciTech Connect (OSTI)

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

    2012-07-01T23:59:59.000Z

    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.

  1. Bacteria Total Maximum Daily Load Task Force Final Report 

    E-Print Network [OSTI]

    Jones, C. Allan; Wagner, Kevin; Di Giovanni, George; Hauck, Larry; Mott, Joanna; Rifai, Hanadi; Srinivasan, Raghavan; Ward, George; Wythe, Kathy

    2009-01-01T23:59:59.000Z

    In September 2006, the Texas Commission on Environmental Quality (TCEQ) and Texas State Soil and Water Conservation Board (TSSWCB) charged a seven-person Bacteria Total Maximum Daily Load (TMDL) Task Force with: * examining approaches...

  2. Maximum Likelihood Decoding of Reed Solomon Codes Madhu Sudan

    E-Print Network [OSTI]

    Sudan, Madhu

    Maximum Likelihood Decoding of Reed Solomon Codes Madhu Sudan Abstract We present a randomized and Welch [4] (see, for instance, Gem- mell and Sudan [9]). In this paper we present an algorithm which

  3. Multi-Class Classification with Maximum Margin Multiple Kernel

    E-Print Network [OSTI]

    Tomkins, Andrew

    (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

  4. Maximum entropy method and oscillations in the diffraction cone

    E-Print Network [OSTI]

    O. Dumbrajs; J. Kontros; A. Lengyel

    2000-07-15T23:59:59.000Z

    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.

  5. Filtering Additive Measurement Noise with Maximum Entropy in the Mean

    E-Print Network [OSTI]

    Henryk Gzyl; Enrique ter Horst

    2007-09-04T23:59:59.000Z

    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.

  6. The maximum entropy tecniques and the statistical description of systems

    E-Print Network [OSTI]

    B. Z. Belashev; M. K. Suleymanov

    2001-10-19T23:59:59.000Z

    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.

  7. X-RAY SPECTRAL VARIABILITY IN NGC 3783

    E-Print Network [OSTI]

    Reis, R. C.

    NGC 3783 was observed for approximately 210 ks by Suzaku and in this time showed significant spectral and flux variability at both short (20 ks) and long (100 ks) timescales. The full observation is found to consist of ...

  8. Field observations of soil moisture variability across scales

    E-Print Network [OSTI]

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

    2008-01-01T23:59:59.000Z

    always bounded by the residual water content and porosity ofi.e. , either the residual water content or the saturatedet al. , 2002]. The residual water content (or irreducible

  9. Stochastic Search with an Observable State Variable Lauren A. Hannah

    E-Print Network [OSTI]

    Powell, Warren B.

    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

  10. Minimum Entangling Power is Close to Its Maximum

    E-Print Network [OSTI]

    Jianxin Chen; Zhengfeng Ji; David W Kribs; Bei Zeng

    2012-10-04T23:59:59.000Z

    Given a quantum gate $U$ acting on a bipartite quantum system, its maximum (average, minimum) entangling power is the maximum (average, minimum) entanglement generation with respect to certain entanglement measure when the inputs are restricted to be product states. In this paper, we mainly focus on the 'weakest' one, i.e., the minimum entangling power, among all these entangling powers. We show that, by choosing von Neumann entropy of reduced density operator or Schmidt rank as entanglement measure, even the 'weakest' entangling power is generically very close to its maximal possible entanglement generation. In other words, maximum, average and minimum entangling powers are generically close. We then study minimum entangling power with respect to other Lipschitiz-continuous entanglement measures and generalize our results to multipartite quantum systems. As a straightforward application, a random quantum gate will almost surely be an intrinsically fault-tolerant entangling device that will always transform every low-entangled state to near-maximally entangled state.

  11. Assessing complexity by means of maximum entropy models

    E-Print Network [OSTI]

    Chliamovitch, Gregor; Velasquez, Lino

    2014-01-01T23:59:59.000Z

    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.

  12. Understanding Biomass Feedstock Variability

    SciTech Connect (OSTI)

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

    2013-01-01T23:59:59.000Z

    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.

  13. Understanding Biomass Feedstock Variability

    SciTech Connect (OSTI)

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

    2013-01-01T23:59:59.000Z

    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.

  14. Partial Observers

    E-Print Network [OSTI]

    Thomas Marlow

    2006-10-20T23:59:59.000Z

    We attempt to dissolve the measurement problem using an anthropic principle which allows us to invoke rational observers. We argue that the key feature of such observers is that they are rational (we need not care whether they are `classical' or `macroscopic' for example) and thus, since quantum theory can be expressed as a rational theory of probabilistic inference, the measurement problem is not a problem.

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

    E-Print Network [OSTI]

    Hanel, Rudolf; Gell-Mann, Murray

    2014-01-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Cofre, Rodrigo

    2014-01-01T23:59:59.000Z

    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.

  17. Maximum likelihood estimation of the equity Efstathios Avdis

    E-Print Network [OSTI]

    Kahana, Michael J.

    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

  18. STATE OF CALIFORNIA MAXIMUM RATED TOTAL COOLING CAPACITY

    E-Print Network [OSTI]

    /09) CALIFORNIA ENERGY COMMISSION INSTALLATION CERTIFICATE CF-6R-MECH-27-HERS Maximum Rated Total Cooling Capacity of the installed system (Btu/hr) 3b Sum of the ARI Rated Total Cooling Capacities of multiple systems installed Cooling Capacities of the installed cooling systems must be calculated and entered in row 3b. 4a MRTCC

  19. annual maximum water: Topics by E-print Network

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

    annual maximum water First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 ORIGINAL PAPER The distribution of...

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

    E-Print Network [OSTI]

    2011-03-16T23:59:59.000Z

    maximum k-colorable subgraph problem consists of selecting a k-color- able induced subgraph of ..... a symmetric subgroup Sp of Aut(G) acts on Vp for all p ? [s]. Let Vp = {vp. 1,...,vp qp. } ...... [9] J. Crawford, M. Ginsberg, E. Luks, and A. Roy.

  1. Renewable Energy Scheduling for Fading Channels with Maximum Power Constraint

    E-Print Network [OSTI]

    Greenberg, Albert

    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

  2. What is a Hurricane? Tropical system with maximum sustained

    E-Print Network [OSTI]

    Meyers, Steven D.

    Andrew-Category 4· Category 4 Hurricane - Winds 131-155 mph. Wall failures in homes and complete roofHurricane 101 #12;What is a Hurricane? · Tropical system with maximum sustained surface wind of 74 mph or greater. A hurricane is the worst and the strongest of all tropical systems. · Also known

  3. Individual Module Maximum Power Point Tracking for Thermoelectric Generator Systems

    E-Print Network [OSTI]

    Schaltz, Erik

    of Thermo Electric Generator (TEG) systems a power converter is often inserted between the TEG system that the TEG system produces the maximum power. However, if the conditions, e.g. temperature, health, age, etc find the best compromise of all modules. In order to increase the power production of the TEG system

  4. Efficiency Improvement of an IPMSM using Maximum Efficiency Operating Strategy

    E-Print Network [OSTI]

    Paderborn, Universität

    Efficiency Improvement of an IPMSM using Maximum Efficiency Operating Strategy Daniel Pohlenz. These are characterized by high efficiency and high torque as well as power density. The generation of reference currents that the MTPC method deviates considerably from the best efficiency under certain boundary conditions. The use

  5. MARTIN'S MAXIMUM AND TOWER FORCING SEAN COX AND MATTEO VIALE

    E-Print Network [OSTI]

    Viale, Matteo

    MARTIN'S MAXIMUM AND TOWER FORCING SEAN COX AND MATTEO VIALE Abstract. There are several examples, the Reflection Princi- ple (RP) implies that if I is a tower of ideals which concentrates on the class GIC1 of 1 [16], shows that if PFA+ or MM holds and there is an inaccessible cardinal, then there is a tower

  6. Retrocommissioning Case Study - Applying Building Selection Criteria for Maximum Results

    E-Print Network [OSTI]

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

    2002-01-01T23:59:59.000Z

    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...

  7. CX Lyrae 2008 Observing Campaign

    E-Print Network [OSTI]

    de Ponthiere, Pierre; Hambsch, Franz-Josef

    2012-01-01T23:59:59.000Z

    The Blazhko effect in CX Lyr has been reported for the first time by Le Borgne et al. (2007). The authors have pointed out that the Blazhko period was not evaluated accurately due to dataset scarcity. The possible period values announced were 128 or 227 days. A newly conducted four-month observing campaign in 2008 (fifty-nine observation nights) has provided fourteen times of maximum. From a period analysis of measured times of maximum, a Blazhko period of 62 +/- 2 days can be suggested. However, the present dataset is still not densely sampled enough to exclude that the measured period is still a modulation of the real Blazhko period. Indeed the shape of the (O-C) curve does not repeat itself exactly during the campaign duration.

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

    E-Print Network [OSTI]

    Otago, University of

    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

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

    E-Print Network [OSTI]

    P. Giommi; P. Padovani; E. Perlman

    1998-02-02T23:59:59.000Z

    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.

  10. Long-term spectroscopic monitoring of the Luminous Blue Variable HD160529

    E-Print Network [OSTI]

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

    2002-12-20T23:59:59.000Z

    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.

  11. Total Solar Irradiance Variability and the Solar Activity Cycle

    E-Print Network [OSTI]

    Probhas Raychaudhuri

    2006-05-06T23:59:59.000Z

    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.

  12. On Maximum Norm of Exterior Product and A Conjecture of C.N. Yang

    E-Print Network [OSTI]

    Zhilin Luo

    2015-01-08T23:59:59.000Z

    Let $V$ be a finite dimensional inner product space over $\\mathbb{R}$ with dimension $n$, where $n\\in \\mathbb{N}$, $\\wedge^{r}V$ be the exterior algebra of $V$, the problem is to find $\\max_{\\| \\xi \\| = 1, \\| \\eta \\| = 1}\\| \\xi \\wedge \\eta \\|$ where $k,l$ $\\in \\mathbb{N},$ $\\forall \\xi \\in \\wedge^{k}V, \\eta \\in \\wedge^{l}V.$ This is a problem suggested by the famous Nobel Prize Winner C.N. Yang. He solved this problem for $k\\leq 2$ in [1], and made the following \\textbf{conjecture} in [2] : If $n=2m$, $k=2r$, $l=2s$, then the maximum is achieved when $\\xi_{max} = \\frac{\\omega^{k}}{\\| \\omega^{k}\\|}, \\eta_{max} = \\frac{\\omega^{l}}{\\| \\omega^{l}\\|}$, where $ \\omega = \\Sigma_{i=1}^m e_{2i-1}\\wedge e_{2i}, $ and $\\{e_{k}\\}_{k=1}^{2m}$ is an orthonormal basis of V. From a physicist's point of view, this problem is just the dual version of the easier part of the well-known Beauzamy-Bombieri inequality for product of polynomials in many variables, which is discussed in [4]. Here the duality is referred as the well known Bose-Fermi correspondence, where we consider the skew-symmetric algebra(alternative forms) instead of the familiar symmetric algebra(polynomials in many variables) In this paper, for two cases we give estimations of the maximum of exterior products, and the Yang's conjecture is answered partially under some special cases.

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

    SciTech Connect (OSTI)

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

    2013-08-01T23:59:59.000Z

    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.

  14. Phylogeography of the Variable Dwarf-Kingfisher Ceyx lepidus (Aves: Alcedinidae) Inferred from Mitochondrial and Nuclear DNA Sequences

    E-Print Network [OSTI]

    Anderson, Michael J.; Oliveros, Carl Hirang; Filardi, Christopher E.; Moyle, Robert G.

    2013-01-01T23:59:59.000Z

    We reconstructed the phylogeographic relationships of the Variable Dwarf-Kingfisher (Ceyx lepidus) using DNA sequence data. Maximum likelihood and Bayesian analysis methods were used to reconstruct trees from a multilocus ...

  15. Maximum Entropy Principle and the Higgs Boson Mass

    E-Print Network [OSTI]

    Alves, Alexandre; da Silva, Roberto

    2014-01-01T23:59:59.000Z

    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.

  16. Maximum Entropy Principle and the Higgs Boson Mass

    E-Print Network [OSTI]

    Alexandre Alves; Alex G. Dias; Roberto da Silva

    2014-11-18T23:59:59.000Z

    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.

  17. Maximum Entry and Mandatory Separation Ages for Certain Security Employees

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

    2001-10-11T23:59:59.000Z

    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.

  18. Occam's Razor Cuts Away the Maximum Entropy Principle

    E-Print Network [OSTI]

    Rudnicki, ?ukasz

    2014-01-01T23:59:59.000Z

    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.

  19. PNNL: A Supervised Maximum Entropy Approach to Word Sense Disambiguation

    SciTech Connect (OSTI)

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

    2007-06-23T23:59:59.000Z

    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.

  20. Some interesting consequences of the maximum entropy production principle

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Crooks, Gavin E.

    2006-01-01T23:59:59.000Z

    1957). J. Skilling, in Maximum Entropy and Bayesian Methods,45–52. J. Skilling, in Maximum Entropy and Bayesian Methods,e C. C. Rodriguez, in Maximum Entropy and Bayesian Methods,

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

    E-Print Network [OSTI]

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

    2007-01-01T23:59:59.000Z

    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

  3. A New Luminous Blue Variable in M31

    E-Print Network [OSTI]

    Humphreys, Roberta M; Gordon, Michael S

    2015-01-01T23:59:59.000Z

    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.

  4. Variable nonlinear resistances

    E-Print Network [OSTI]

    Howard, James Edgar

    1955-01-01T23:59:59.000Z

    VARIETAL". NONLINEAR RESIS'IANCES A Thes1s JA'. 4ES EDGAR HOWARD as to style and content by Head Department January 1955 LIBRARY A 4 IS COLLEGE PF TEXAS VARIABLE NONLINEAR RESISTANCES A Thesis By JAMES EDGAR HOWARD Submitted...

  5. Device for adapting continuously variable transmissions to infinitely variable transmissions with forward-neutral-reverse capabilities

    DOE Patents [OSTI]

    Wilkes, Donald F. (Albuquerque, NM); Purvis, James W. (Albuquerque, NM); Miller, A. Keith (Albuquerque, NM)

    1997-01-01T23:59:59.000Z

    An infinitely variable transmission is capable of operating between a maximum speed in one direction and a minimum speed in an opposite direction, including a zero output angular velocity, while being supplied with energy at a constant angular velocity. Input energy is divided between a first power path carrying an orbital set of elements and a second path that includes a variable speed adjustment mechanism. The second power path also connects with the orbital set of elements in such a way as to vary the rate of angular rotation thereof. The combined effects of power from the first and second power paths are combined and delivered to an output element by the orbital element set. The transmission can be designed to operate over a preselected ratio of forward to reverse output speeds.

  6. ULTRACAM photometry of eclipsing cataclysmic variable stars

    E-Print Network [OSTI]

    William James Feline

    2008-06-04T23:59:59.000Z

    The accurate determination of the masses of cataclysmic variable stars is critical to our understanding of their origin, evolution and behaviour. Observations of cataclysmic variables also afford an excellent opportunity to constrain theoretical physical models of the accretion discs housed in these systems. In particular, the brightness distributions of the accretion discs of eclipsing systems can be mapped at a spatial resolution unachievable in any other astrophysical situation. This thesis addresses both of these important topics via the analysis of the light curves of six eclipsing dwarf novae, obtained using ULTRACAM, a novel high-speed imaging photometer.

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

    E-Print Network [OSTI]

    2006-10-31T23:59:59.000Z

    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.

  8. Interdiurnal temperature variability over the conterminous United States and Canada 

    E-Print Network [OSTI]

    Rice, Peter Bruce

    1988-01-01T23:59:59.000Z

    the mean interdiurnal temperature vari- ability (MITV) of maximum, minimum, or mean temperature for this period. The periods usually chosen in climatological studies are the twelve months, and when the n-I values characterizing a particular month of n... required to obtai n stability of means . They both determined that periods of rapidly changing warm and cold air masses are associated with large mean interdiurnal temperature variability. Landsberg chose a five-year period, 1957-1961, based on Ca...

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

    E-Print Network [OSTI]

    P. Giommi; P. Padovani; E. Perlman

    1999-07-27T23:59:59.000Z

    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.

  10. Variable depth core sampler

    DOE Patents [OSTI]

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

    1996-02-20T23:59:59.000Z

    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.

  11. Variable Crop Share Leases.

    E-Print Network [OSTI]

    Sartin, Marvin; Sammons, Ray

    1980-01-01T23:59:59.000Z

    )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...

  12. Variable Frequency Pump Drives

    E-Print Network [OSTI]

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

    . In a conventional pump and driver arrangement (for example, a centrifugal pump coupled to an AC induction motor'with no speed control provision), the motor runs at. a constant speed, which is determined by the incoming line frequency, and the pump... when it is needed. LONG RANGE DESIGN TRENDS The growing use of variable-frequency electric motor drives will permit the integration of 60 and 50 cycle pump lines. One important concern for future improvements is the growing possibility...

  13. Better Nonlinear Models from Noisy Data: Attractors with Maximum Likelihood

    E-Print Network [OSTI]

    Patrick E. McSharry; Leonard A. Smith

    1999-11-30T23:59:59.000Z

    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.

  14. Application of Maximum Entropy Method to Dynamical Fermions

    E-Print Network [OSTI]

    Jonathan Clowser; Costas Strouthos

    2001-10-16T23:59:59.000Z

    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.

  15. Improving predictability of time series using maximum entropy methods

    E-Print Network [OSTI]

    Gregor Chliamovitch; Alexandre Dupuis; Bastien Chopard; Anton Golub

    2014-11-28T23:59:59.000Z

    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.

  16. Reducing Degeneracy in Maximum Entropy Models of Networks

    E-Print Network [OSTI]

    Horvát, Szabolcs; Toroczkai, Zoltán

    2014-01-01T23:59:59.000Z

    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.

  17. Improving predictability of time series using maximum entropy methods

    E-Print Network [OSTI]

    Chliamovitch, Gregor; Chopard, Bastien; Golub, Anton

    2014-01-01T23:59:59.000Z

    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.

  18. Excited nucleon spectrum from lattice QCD with maximum entropy method

    E-Print Network [OSTI]

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

    2003-09-29T23:59:59.000Z

    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 $N^*(1535)$.

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

    SciTech Connect (OSTI)

    Canavan, G.H.

    1997-03-01T23:59:59.000Z

    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.

  20. THE OPTICAL GRAVITATIONAL LENSING EXPERIMENT. THE CATALOG OF PERIODIC VARIABLE STARS IN THE GALACTIC BULGE. I. PERIODIC VARIABLES IN THE CENTER OF THE BAADE'S WINDOW.

    E-Print Network [OSTI]

    A. UDALSKI; M. KUBIAK; M. SZYMANSKI; J. KALUZNY; M. MATEO; W. KRZEMINSKI

    1995-01-09T23:59:59.000Z

    This paper is the first part of the Catalog of Periodic Variable Stars in the Galactic bulge. The Catalog is based on observations collected during the OGLE microlensing search. 213 periodic variable stars brighter than I=18 mag: 31 pulsating, 116 eclipsing and 66 miscellaneous type variables from the Baade's Window BWC field are presented. Periodic variable stars from remaining 20 fields will be presented in similar form in the next parts of the Catalog. The Catalog as well as observations of all periodic variable objects are available to astronomical community over the Internet network.

  1. Probable maximum flood control; Yucca Mountain Site Characterization Project

    SciTech Connect (OSTI)

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

    1991-11-01T23:59:59.000Z

    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.

  2. Maximum Margin Clustering for State Decomposition of Metastable Systems

    E-Print Network [OSTI]

    Wu, Hao

    2015-01-01T23:59:59.000Z

    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...

  3. Efficiency at maximum power of a chemical engine

    E-Print Network [OSTI]

    Hooyberghs, Hans; Salazar, Alberto; Indekeu, Joseph O; Broeck, Christian Van den

    2013-01-01T23:59:59.000Z

    A cyclically operating chemical engine is considered that converts chemical energy into mechanical work. The working fluid is a gas of finite-sized spherical particles interacting through elastic hard collisions. For a generic transport law for particle uptake and release, the efficiency at maximum power $\\eta$ takes the form 1/2+c\\Delta \\mu + O(\\Delta \\mu^2), with 1/2 a universal constant and $\\Delta \\mu$ the chemical potential difference between the particle reservoirs. The linear coefficient c is zero for engines featuring a so-called left/right symmetry or particle fluxes that are antisymmetric in the applied chemical potential difference. Remarkably, the leading constant in $\\eta$ is non-universal with respect to an exceptional modification of the transport law. For a nonlinear transport model we obtain \\eta = 1/(\\theta +1), with \\theta >0 the power of $\\Delta \\mu$ in the transport equation

  4. Reduction in maximum time uncertainty of paired time signals

    DOE Patents [OSTI]

    Theodosiou, George E. (West Chicago, IL); Dawson, John W. (Clarendon Hills, IL)

    1983-01-01T23:59:59.000Z

    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 .ltoreq.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 20-800.

  5. Reduction in maximum time uncertainty of paired time signals

    DOE Patents [OSTI]

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

    1983-10-04T23:59:59.000Z

    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][<=]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--800. 6 figs.

  6. Reduction in maximum time uncertainty of paired time signals

    DOE Patents [OSTI]

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

    1981-02-11T23:59:59.000Z

    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.

  7. Improved Maximum Entropy Analysis with an Extended Search Space

    E-Print Network [OSTI]

    Alexander Rothkopf

    2013-01-07T23:59:59.000Z

    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.

  8. Quantum maximum entropy principle for a system of identical particles

    SciTech Connect (OSTI)

    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

    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.

  9. Atmospheric Noise in Single Dish Observations

    E-Print Network [OSTI]

    Militzer, Burkhard

    the errors in a wideband total power measurement. Noise con­ tributions come from thermal noise consider total power measurements with a single dish radiometer. The measured total power, p[K] = g \\Theta for extended sources. For wideband total power observations, the maximum integration time ¸ 0.1 s in order

  10. Spectrum of Controlling and Observing Complex Networks

    E-Print Network [OSTI]

    Yan, Gang; Barzel, Baruch; Slotine, Jean-Jacques; Liu, Yang-Yu; Barabasi, Albert-Laszlo

    2015-01-01T23:59:59.000Z

    Observing and controlling complex networks are of paramount interest for understanding complex physical, biological and technological systems. Recent studies have made important advances in identifying sensor or driver nodes, through which we can observe or control a complex system. Yet, the observation uncertainty induced by measurement noise and the energy cost required for control continue to be significant challenges in practical applications. Here we show that the control energy cost and the observation uncertainty vary widely in different directions of the state space. In particular, we find that if all nodes are directly driven, control is energetically feasible, as the maximum energy cost increases sublinearly with the system size. If, however, we aim to control a system by driving only a single node, control in some directions is energetically prohibitive, increasing exponentially with the system size. For the cases in between, the maximum energy decays exponentially if we increase the number of driv...

  11. Quantifying extrinsic noise in gene expression using the maximum entropy framework

    E-Print Network [OSTI]

    Purushottam D. Dixit

    2013-04-04T23:59:59.000Z

    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.

  12. Predicting Whole Forest Structure, Primary Productivity, and Biomass Density From Maximum Tree Size and Resource Limitations

    E-Print Network [OSTI]

    Kempes, Christopher P; Dooris, William; West, Geoffrey B

    2015-01-01T23:59:59.000Z

    In the face of uncertain biological response to climate change and the many critiques concerning model complexity it is increasingly important to develop predictive mechanistic frameworks that capture the dominant features of ecological communities and their dependencies on environmental factors. This is particularly important for critical global processes such as biomass changes, carbon export, and biogenic climate feedback. Past efforts have successfully understood a broad spectrum of plant and community traits across a range of biological diversity and body size, including tree size distributions and maximum tree height, from mechanical, hydrodynamic, and resource constraints. Recently it was shown that global scaling relationships for net primary productivity are correlated with local meteorology and the overall biomass density within a forest. Along with previous efforts, this highlights the connection between widely observed allometric relationships and predictive ecology. An emerging goal of ecological...

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

    E-Print Network [OSTI]

    Giffin, Adom

    2009-01-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2011-03-14T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Kiyoshi Sasaki; Shoichi Sasaki; Tetsuo Hatsuda

    2005-07-12T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

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

    2002-08-19T23:59:59.000Z

    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.

  17. Savannah River Site radioiodine atmospheric releases and offsite maximum doses

    SciTech Connect (OSTI)

    Marter, W.L.

    1990-11-01T23:59:59.000Z

    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.

  18. LANDFILL OPERATION FOR CARBON SEQUESTRATION AND MAXIMUM METHANE EMISSION CONTROL

    SciTech Connect (OSTI)

    Don Augenstein

    2001-02-01T23:59:59.000Z

    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.

  19. Maximum Entropy Analysis of the Spectral Functions in Lattice QCD

    E-Print Network [OSTI]

    M. Asakawa; T. Hatsuda; Y. Nakahara

    2001-02-26T23:59:59.000Z

    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.

  20. Improved Maximum Entropy Method with an Extended Search Space

    E-Print Network [OSTI]

    Alexander Rothkopf

    2012-08-25T23:59:59.000Z

    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.

  1. Maximum entropy detection of planets around active stars

    E-Print Network [OSTI]

    Petit, P; Hébrard, E; Morin, J; Folsom, C P; Böhm, 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

    (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...

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

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Maximum Power Point Tracking Control for Photovoltaic System Using Adaptive Neuro- Fuzzy "ANFIS energy demand. The mathematical modeling and simulation of the photovoltaic system is implemented) like ANFIS. This paper presents Maximum Power Point Tracking Control for Photovoltaic System Using

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

    E-Print Network [OSTI]

    Isaac Shlosman; Peter Vitello; Christopher W. Mauche

    1995-11-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Borwein, Jonathan

    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

  5. Universalities in hadron production and the maximum entropy principle

    E-Print Network [OSTI]

    A. Kropivnitskaya; A. Rostovtsev

    2005-01-04T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Richardson, David

    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

  7. 1 A MAXIMUM ENTROPY METHOD FOR SUBNETWORK ORIGIN-DESTINATION 2 TRIP MATRIX ESTIMATION

    E-Print Network [OSTI]

    Kockelman, Kara M.

    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

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

    E-Print Network [OSTI]

    Perloff, Jeffrey M.

    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

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

    E-Print Network [OSTI]

    Perloff, Jeffrey M.

    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

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

    E-Print Network [OSTI]

    Kockelman, Kara M.

    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

  11. Envera Variable Compression Ratio Engine

    SciTech Connect (OSTI)

    Charles Mendler

    2011-03-15T23:59:59.000Z

    Aggressive engine downsizing, variable compression ratio and use of the Atkinson cycle are being combined to improve fuel economy by up to 40 percent relative to port fuel injected gasoline engines, while maintaining full engine power. Approach Engine downsizing is viewed by US and foreign automobile manufacturers as one of the best options for improving fuel economy. While this strategy has already demonstrated a degree of success, downsizing and fuel economy gains are currently limited. With new variable compression ratio technology however, the degree of engine downsizing and fuel economy improvement can be greatly increased. A small variable compression ratio (VCR) engine has the potential to return significantly higher vehicle fuel economy while also providing high power. Affordability and potential for near term commercialization are key attributes of the Envera VCR engine. VCR Technology To meet torque and power requirements, a smaller engine needs to do more work per stroke. This is typically accomplished by boosting the incoming charge with either a turbo or supercharger so that more energy is present in the cylinder per stroke to do the work. With current production engines the degree of engine boosting (which correlates to downsizing) is limited by detonation (combustion knock) at high boost levels. Additionally, the turbo or supercharger needs to be responsive and efficient while providing the needed boost. VCR technology eliminates the limitation of engine knock at high load levels by reducing compression ratio to {approx}9:1 (or whatever level is appropriate) when high boost pressures are needed. By reducing the compression ratio during high load demand periods there is increased volume in the cylinder at top dead center (TDC) which allows more charge (or energy) to be present in the cylinder without increasing the peak pressure. Cylinder pressure is thus kept below the level at which the engine would begin to knock. When loads on the engine are low the compression ratio can be raised (to as much as 18:1) providing high engine efficiency. It is important to recognize that for a well designed VCR engine cylinder pressure does not need to be higher than found in current production turbocharged engines. As such, there is no need for a stronger crankcase, bearings and other load bearing parts within the VCR engine. The Envera VCR mechanism uses an eccentric carrier approach to adjust engine compression ratio. The crankshaft main bearings are mounted in this eccentric carrier or 'crankshaft cradle' and pivoting the eccentric carrier 30 degrees adjusts compression ratio from 9:1 to 18:1. The eccentric carrier is made up of a casting that provides rigid support for the main bearings, and removable upper bearing caps. Oil feed to the main bearings transits through the bearing cap fastener sockets. The eccentric carrier design was chosen for its low cost and rigid support of the main bearings. A control shaft and connecting links are used to pivot the eccentric carrier. The control shaft mechanism features compression ratio lock-up at minimum and maximum compression ratio settings. The control shaft method of pivoting the eccentric carrier was selected due to its lock-up capability. The control shaft can be rotated by a hydraulic actuator or an electric motor. The engine shown in Figures 3 and 4 has a hydraulic actuator that was developed under the current program. In-line 4-cylinder engines are significantly less expensive than V engines because an entire cylinder head can be eliminated. The cost savings from eliminating cylinders and an entire cylinder head will notably offset the added cost of the VCR and supercharging. Replacing V6 and V8 engines with in-line VCR 4-cylinder engines will provide high fuel economy at low cost. Numerous enabling technologies exist which have the potential to increase engine efficiency. The greatest efficiency gains are realized when the right combination of advanced and new technologies are packaged together to provide the greatest gains at the least cost. Aggressive engine downsiz

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

    E-Print Network [OSTI]

    Jack, D; Hauschildt, P H

    2015-01-01T23:59:59.000Z

    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 ...

  13. Pitch-controlled variable-speed wind turbine generation

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C.P.

    2000-03-01T23:59:59.000Z

    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.

  14. Convex relaxation methods for graphical models : Lagrangian and maximum entropy approaches

    E-Print Network [OSTI]

    Johnson, Jason K. (Jason Kyle)

    2008-01-01T23:59:59.000Z

    Graphical models provide compact representations of complex probability distributions of many random variables through a collection of potential functions defined on small subsets of these variables. This representation ...

  15. Harmonic propagation of variability in surface energy balance within a coupled soilvegetationatmosphere system

    E-Print Network [OSTI]

    Gentine, Pierre

    Harmonic propagation of variability in surface energy balance within a coupled energy balance. The amplitude of the noise is maximum at midday when the incoming radiative forcing results in changes in the surface energy balance through the modification of outgoing radiative, turbulent

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

    E-Print Network [OSTI]

    Wang, Chunzai

    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

  17. LANDFILL OPERATION FOR CARBON SEQUESTRATION AND MAXIMUM METHANE EMISSION CONTROL

    SciTech Connect (OSTI)

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

    2000-02-26T23:59:59.000Z

    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.

  18. 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]

    Massachusetts at Amherst, University of

    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

  19. Time resolved spectroscopy of the variable brown dwarf Kelu-1

    E-Print Network [OSTI]

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

    2003-01-09T23:59:59.000Z

    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%.

  20. Variable rate CELP speech coding using widely variable parameter updates

    E-Print Network [OSTI]

    Moodie, Myron L.

    1995-01-01T23:59:59.000Z

    bit rates for a given quality level. This work develops new techniques, referred to as widely variable CELP parameter updates, which dynamically adapt the transmit frequency of the CELP spectral parameters to the characteristics of the input speech...

  1. A maximum entropy framework for non-exponential distributions

    E-Print Network [OSTI]

    Peterson, Jack; Dill, Ken A

    2015-01-01T23:59:59.000Z

    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.

  2. Quantum information with modular variables

    E-Print Network [OSTI]

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

    2014-06-24T23:59:59.000Z

    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.

  3. VARIABILITY OF KD VALUES IN CEMENTITIOUS MATERIALS AND SEDIMENTS

    SciTech Connect (OSTI)

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

    2012-02-02T23:59:59.000Z

    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).

  4. MID-INFRARED SPECTRAL VARIABILITY ATLAS OF YOUNG STELLAR OBJECTS

    SciTech Connect (OSTI)

    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

    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.

  5. Using the Comoving Maximum of the Galaxy Power Spectrum to Measure Cosmological Curvature

    E-Print Network [OSTI]

    Tom Broadhurst; Andrew H. Jaffe

    1999-04-26T23:59:59.000Z

    The large-scale maximum at k~0.05 identified in the power-spectrum of galaxy fluctuations provides a co-moving scale for measuring cosmological curvature. In shallow 3D surveys the peak is broad, but appears to be well resolved in 1D, at ~130 Mpc (k=0.048), comprising evenly spaced peaks and troughs. Surprisingly similar behaviour is evident at z=3 in the distribution of Lyman-break galaxies, for which we find a 5 sigma excess of pairs separated by Delta z=0.22pm0.02, equivalent to 85Mpc for Omega=1, increasing to 170 Mpc for Omega=0, with a number density contrast of 30% averaged over 5 independent fields. The combination, 3.2\\Omega_m -\\Omega_{\\Lambda}=0.7, matches the local scale of 130 Mpc, i.e. Omega=0.2\\pm0.1 or Omega_{m}=0.4\\pm0.1 for the matter-dominated and flat models respectively, with an uncertainty given by the width of the excess correlation. The consistency here of the flat model with SNIa based claims is encouraging, but overshadowed by the high degree of coherence observed in 1D compared with conventional Gaussian models of structure formation. The appearance of this scale at high redshift and its local prominence in the distribution of Abell clusters lends support to claims that the high-z `spikes' represent young clusters. Finally we show that a spike in the primordial power spectrum of delta\\rho/\\rho=0.3 at k=0.05 has little effect on the CMB, except to exaggerate the first Doppler peak in flat matter-dominated models, consistent with recent observations. \\\\effect on the CMB, except to exaggerate the first Doppler peak in flat matter-dominated models, consistent with recent observations.

  6. Anyonic statistics with continuous variables

    E-Print Network [OSTI]

    Jing Zhang; Changde Xie; Kunchi Peng; Peter van Loock

    2008-10-30T23:59:59.000Z

    We describe a continuous-variable scheme for simulating the Kitaev lattice model and for detecting statistics of abelian anyons. The corresponding quantum optical implementation is solely based upon Gaussian resource states and Gaussian operations, hence allowing for a highly efficient creation, manipulation, and detection of anyons. This approach extends our understanding of the control and application of anyons and it leads to the possibility for experimental proof-of-principle demonstrations of anyonic statistics using continuous-variable systems.

  7. Variable metric conjugate gradient methods

    SciTech Connect (OSTI)

    Barth, T.; Manteuffel, T.

    1994-07-01T23:59:59.000Z

    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.

  8. IS ACTIVE REGION CORE VARIABILITY AGE DEPENDENT?

    SciTech Connect (OSTI)

    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

    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.

  9. A PHOTOMETRICALLY AND MORPHOLOGICALLY VARIABLE INFRARED NEBULA IN L483

    SciTech Connect (OSTI)

    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

    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.

  10. VSOP Observations of the Blazar S5 2007+77

    E-Print Network [OSTI]

    K. E. Gabanyi; T. P. Krichbaum; A. Kraus; A. Witzel; J. A. Zensus

    2008-02-05T23:59:59.000Z

    The blazar, S5 2007+77 shows intraday variability in cm wavelengths. Seven epochs of VSOP observations were carried out in 1998 and 1999 at 5 GHz to look for the origin of the variability with the highest achievable angular resolution at cm wavelengths. Here the results of four epochs are analysed, which revealed ~10% variations in polarized flux density.

  11. Effect of linear lumping on controllability and observability

    E-Print Network [OSTI]

    Tóth, János

    Effect of linear lumping on controllability and observability Zs´ofia Horv´ath October 2006 Email to reduce the number of state variables on controllability and observability of linear differential the effect of linear lumping on such properties of the system as controllability and observability and apply

  12. Fluid observers and tilting cosmology

    E-Print Network [OSTI]

    A. A. Coley; S. Hervik; W. C. Lim

    2006-05-24T23:59:59.000Z

    We study perfect fluid cosmological models with a constant equation of state parameter $\\gamma$ in which there are two naturally defined time-like congruences, a geometrically defined geodesic congruence and a non-geodesic fluid congruence. We establish an appropriate set of boost formulae relating the physical variables, and consequently the observed quantities, in the two frames. We study expanding spatially homogeneous tilted perfect fluid models, with an emphasis on future evolution with extreme tilt. We show that for ultra-radiative equations of state (i.e., $\\gamma>4/3$), generically the tilt becomes extreme at late times and the fluid observers will reach infinite expansion within a finite proper time and experience a singularity similar to that of the big rip. In addition, we show that for sub-radiative equations of state (i.e., $\\gamma < 4/3$), the tilt can become extreme at late times and give rise to an effective quintessential equation of state. To establish the connection with phantom cosmology and quintessence, we calculate the effective equation of state in the models under consideration and we determine the future asymptotic behaviour of the tilting models in the fluid frame variables using the boost formulae. We also discuss spatially inhomogeneous models and tilting spatially homogeneous models with a cosmological constant.

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

    E-Print Network [OSTI]

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

    2002-12-12T23:59:59.000Z

    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.

  14. Managing Variability throughout the Software Development Lifecycle

    E-Print Network [OSTI]

    Managing Variability throughout the Software Development Lifecycle Neil Loughran and Awais Rashid levels of the software development lifecycle, especially when new requirements arise. We believe of the software development lifecycle. Moreover, the effects of variability and, in particular, new variabilities

  15. Observing Healthcare Interior Environments and the Effect on Patient Behavior 

    E-Print Network [OSTI]

    Rice, Courtney R.

    2010-07-14T23:59:59.000Z

    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...

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

    SciTech Connect (OSTI)

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

    2009-03-20T23:59:59.000Z

    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.

  17. The number e^{(1/2)} is the ratio between the time of maximum value and the time of maximum growth rate for restricted growth phenomena?

    E-Print Network [OSTI]

    Zi-Niu Wu

    2013-10-02T23:59:59.000Z

    For many natural process of growth, with the growth rate independent of size due to Gibrat law and with the growth process following a log-normal distribution, the ratio between the time (D) for maximum value and the time (L) for maximum growth rate (inflexion point) is then equal to the square root of the base of the natural logarithm (e^{1/2}). On the logarithm scale this ratio becomes one half ((1/2)). It remains an open question, due to lack of complete data for various cases with restricted growth, whether this e^{1/2} ratio can be stated as e^{1/2}-Law. Two established examples already published, one for an epidemic spreading and one for droplet production, support however this ratio. Another example appears to be the height of humain body. For boys the maximum height occurs near 23 years old while the maximum growth rate is at the age near 14, and there ratio is close to e^{1/2}. The main theoretical base to obtain this conclusion is problem independent, provided the growth process is restricted, such as public intervention to control the spreading of communicable epidemics, so that an entropy is associated with the process and the role of dissipation, representing the mechanism of intervention, is maximized. Under this formulation the principle of maximum rate of entropy production is used to make the production process problem independent.

  18. Use of Two Distillation Columns in Systems with Maximum Temperature Limitations

    E-Print Network [OSTI]

    Gilchrist, James F.

    Use of Two Distillation Columns in Systems with Maximum Temperature Limitations Rebecca H. Masel, Pennsylvania 18015, United States ABSTRACT: Maximum temperature limitations are encountered in distillation of the bottoms product fixes the column base pressure and, hence, the condenser pressure. The distillate

  19. Maximum Power Transfer Tracking in a Solar USB Charger for Smartphones

    E-Print Network [OSTI]

    Pedram, Massoud

    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

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

    E-Print Network [OSTI]

    California at Berkeley, University of

    ). 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

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

    E-Print Network [OSTI]

    Wang, Yuqing

    Energy Production, Frictional Dissipation, and Maximum Intensity of a Numerically Simulated is eventually dissipated due to surface friction. Since the energy production rate is a linear function while frictional dissipation rate balances the energy production rate near the radius of maximum wind (RMW

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

    E-Print Network [OSTI]

    Wang, Yuqing

    0 Energy Production, Frictional Dissipation, and Maximum Intensity of a Numerically Simulated is eventually dissipated due to surface friction. Since the energy production rate is a linear function while frictional dissipation rate balances the energy production rate near the radius of maximum wind (RMW

  3. Efficiency at maximum power of low dissipation Carnot engines Massimiliano Esposito

    E-Print Network [OSTI]

    Kawai, Ryoichi

    Efficiency at maximum power of low dissipation Carnot engines Massimiliano Esposito Center the efficiency at maximum power, , of engines performing finite-time Carnot cycles between a hot and a cold reservoir at temperatures Th and Tc, respectively. For engines reaching Carnot efficiency C = 1 - Tc

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

    E-Print Network [OSTI]

    Fujimoto, Hiroshi

    » «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

  5. An Improved Maximum Likelihood Formulation for Accurate Genome Assembly Aditya Varma, Abhiram Ranade and Srinivas Aluru

    E-Print Network [OSTI]

    Ranade, Abhiram G.

    An Improved Maximum Likelihood Formulation for Accurate Genome Assembly Aditya Varma, Abhiram maximum likelihood method for genome assembly. We formulate the problem as one of direct convex estimate of the length of the genome or the need to use further expectation minimization to predict

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

    E-Print Network [OSTI]

    I. B. Khriplovich; R. V. Korkin

    2001-12-27T23:59:59.000Z

    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.

  7. OBSERVING CORONAL NANOFLARES IN ACTIVE REGION MOSS

    SciTech Connect (OSTI)

    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

    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).

  8. Analyticity, Convergence and Convergence Rate of Recursive Maximum Likelihood Estimation in Hidden Markov Models

    E-Print Network [OSTI]

    Tadi?, Vladislav B

    2009-01-01T23:59:59.000Z

    This paper considers the asymptotic properties of the recursive maximum likelihood estimation in hidden Markov models. The paper is focused on the asymptotic behavior of the log-likelihood function and on the point-convergence and convergence rate of the recursive maximum likelihood estimator. Using the principle of analytical continuation, the analyticity of the asymptotic log-likelihood function is shown for analytically parameterized hidden Markov models. Relying on this fact and some results from differential geometry (Lojasiewicz inequality), the almost sure point-convergence of the recursive maximum likelihood algorithm is demonstrated, and relatively tight bounds on the convergence rate are derived. As opposed to the existing result on the asymptotic behavior of maximum likelihood estimation in hidden Markov models, the results of this paper are obtained without assuming that the log-likelihood function has an isolated maximum at which the Hessian is strictly negative definite.

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

    E-Print Network [OSTI]

    Kinney, Justin B

    2014-01-01T23:59:59.000Z

    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.

  10. Variable Structure Control of a

    E-Print Network [OSTI]

    Ge, Shuzhi Sam

    . INTRODUCTION Modelling and control of flexible link manipulators have been studied intensively controller for regulation of a flexible beam. Due to its simplicity and robustness to parametricVariable Structure Control of a Distributed-Parameter Flexible Beam S. S. Ge,* T. H. Lee, G. Zhu, F

  11. Operating Reserves and Variable Generation

    SciTech Connect (OSTI)

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

    2011-08-01T23:59:59.000Z

    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.

  12. Interrelationships among alternative export variables and their impacts on corn prices

    E-Print Network [OSTI]

    Clarke, Somkid Tammakrut

    1987-01-01T23:59:59.000Z

    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...

  13. A comparison of light and velocity variations in Semiregular variables

    E-Print Network [OSTI]

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

    2000-09-21T23:59:59.000Z

    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.

  14. Variable Interactions in Query-Driven Visualization

    SciTech Connect (OSTI)

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

    2007-10-25T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Nikolaidis, Efstratios

    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

  16. On the near infrared variability of chemically peculiar stars

    E-Print Network [OSTI]

    F. A. Catalano; F. Leone

    1998-05-06T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2011-08-19T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Zhang, Bing

    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

  19. Contributions to sea level variability along the Norwegian coast for 19602010

    E-Print Network [OSTI]

    Drange, Helge

    Contributions to sea level variability along the Norwegian coast for 1960­2010 K. Richter,1,2 J. E the Norwegian coast. The residual (observed minus reconstructed) shows a positive trend ranging from 1.3 mm yrÀ1 variability along the Norwegian coast for 1960­2010, J. Geophys. Res., 117, C05038, doi:10.1029/2011JC007826

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

    E-Print Network [OSTI]

    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

    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.

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

    E-Print Network [OSTI]

    Dail, Holly Janine

    2012-01-01T23:59:59.000Z

    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? ...

  2. Investigating the angle or response and maximum stability of a cohesive granular pile

    E-Print Network [OSTI]

    Nowak, Sara Alice, 1982-

    2004-01-01T23:59:59.000Z

    In this thesis, I investigate the static and dynamic properties of a granular heap made cohesive by an interstitial fluid. I present the results of experimental work measuring the maximum angle of stability and the angle ...

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

    E-Print Network [OSTI]

    Wunsch, Carl

    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 ...

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

    E-Print Network [OSTI]

    Kroeger, Timothy H

    2013-09-19T23:59:59.000Z

    , revealing the premixed and diffusion burn fractions as well as important engine and exhaust design criteria such as maximum in-cylinder pressure and exhaust composition. These results are significant in diesel engine design because cheaper, lighter engines...

  5. Microcontroller Servomotor for Maximum Effective Power Point for Solar Cell System 

    E-Print Network [OSTI]

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

    2010-01-01T23:59:59.000Z

    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 ...

  6. Submodule Integrated Distributed Maximum Power Point Tracking for Solar Photovoltaic Applications

    E-Print Network [OSTI]

    Pilawa-Podgurski, Robert C. N.

    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 ...

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

    E-Print Network [OSTI]

    Gülder, Ömer L.

    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

  8. Microcontroller Servomotor for Maximum Effective Power Point for Solar Cell System

    E-Print Network [OSTI]

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

    2010-01-01T23:59:59.000Z

    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...

  9. Maximum Network Lifetime in Wireless Sensor Networks with Adjustable Sensing Ranges

    E-Print Network [OSTI]

    Wu, Jie

    1 Maximum Network Lifetime in Wireless Sensor Networks with Adjustable Sensing Ranges Mihaela problem in wireless sensor networks with adjustable sensing range. Communication and sensing consume Wireless sensor networks (WSNs) constitute the foundation of a broad range of applications related

  10. Parameterization of Maximum Wave Heights Forced by Hurricanes: Application to Corpus Christi, Texas

    E-Print Network [OSTI]

    Taylor, Sym 1978-

    2012-12-07T23:59:59.000Z

    sensitivity based on the investigation of several hurricane parameters. Also presented is the development of parameterized maximum significant wave height models. These are determined by incorporating three forms of an equivalent fetch into (1) dimensionless...

  11. A more efficient formulation for computation of the maximum loading points in electric power systems

    SciTech Connect (OSTI)

    Chiang, H.D. [Cornell Univ., Ithaca, NY (United States). School of Electrical Engineering; Jean-Jumeau, R. [Electricite d`Haita, Port-au-Prince (Haiti)

    1995-05-01T23:59:59.000Z

    This paper presents a more efficient formulation for computation of the maximum loading points. A distinguishing feature of the new formulation is that it is of dimension (n + 1), instead of the existing formulation of dimension (2n + 1), for n-dimensional load flow equations. This feature makes computation of the maximum loading points very inexpensive in comparison with those required in the existing formulation. A theoretical basis for the new formulation is provided. The new problem formulation is derived by using a simple reparameterization scheme and exploiting the special properties of the power flow model. Moreover, the proposed test function is shown to be monotonic in the vicinity of a maximum loading point. Therefore, it allows one to monitor the approach to maximum loading points during the solution search process. Simulation results on a 234-bus system are presented.

  12. Acoustic Space Dimensionality Selection and Combination using the Maximum Entropy Principle 

    E-Print Network [OSTI]

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

    2004-01-01T23:59:59.000Z

    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...

  13. Correlation of meteorological variables with total suspended particulate matter in Harris County, Texas

    E-Print Network [OSTI]

    White, G. Anderson

    1983-01-01T23:59:59.000Z

    conducive to pollutant transport into their respective regions. Thurston and Spengler did not attempt to relate a single event, such as pollution level, to meteorological conditions. Allender and Dejardin (1981) used a statistical method to predict air.... Meteorological variables used were maximum temperature, 1800 LST wind speed, and cosine of the wind direction at 0000 LST for the day previous to the forecast period. Selection of these parameters came from previous work. Allender and Dejardin claimed 85...

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

    E-Print Network [OSTI]

    Burgess, Stephen

    2012-03-06T23:59:59.000Z

    HWE Hardy–Weinberg 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...

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

    E-Print Network [OSTI]

    Servedio, Rocco

    . 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

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

    E-Print Network [OSTI]

    Malhotra, M.; Haberl, J. S.

    2006-01-01T23:59:59.000Z

    Systems in Hot and Humid Climates, Orlando, Florida, July 24-26, 2006 Methodology 1. Development of the Basecase Simulation Model 2. Analysis of Energy Saving Measures 3. Development of the Maximum Energy-Efficient House 4. Economic Analysis DOE-2 Input...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...

  17. ON THE PROBLEM OF UNIQUENESS FOR THE MAXIMUM STIRLING NUMBER(S) OF THE SECOND KIND

    E-Print Network [OSTI]

    Pomerance, Carl

    ON THE PROBLEM OF UNIQUENESS FOR THE MAXIMUM STIRLING NUMBER(S) OF THE SECOND KIND E. Rodney Say that an integer n is exceptional if the maximum Stirling number of the second kind S(n, k) occurs or equal to x is O(x3/5+ ), for any > 0. 1. Introduction Let S(n, k) be the Stirling number of the second

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

    E-Print Network [OSTI]

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

    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...

  19. Cranial Variability in Amazonian Marmosets

    E-Print Network [OSTI]

    Aguiar, John Marshall

    2011-02-22T23:59:59.000Z

    (Callithrix, Callitrichidae) have been discovered in recent years, as well as the exceptional dwarf marmoset Callibella humilis. Most of these species were described on the basis of their pelage and presumed separation by major rivers. I performed... analyses of craniometric variables by taxa and by river basins, in order to determine if there are significant cranial distinctions between taxa separated by rivers. I analyzed quantitative cranial and mandibular characters of Callibella humilis...

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

    SciTech Connect (OSTI)

    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

    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.

  1. Removing the Microlensing Blending-Parallax Degeneracy Using Source Variability

    E-Print Network [OSTI]

    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; Fouqué, P; Glicenstein, J F; Goldman, B; Graff, D; Gros, M; Haïssinski, 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

    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.

  2. The role of an accretion disk in AGN variability

    E-Print Network [OSTI]

    B. Czerny

    2004-09-10T23:59:59.000Z

    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.

  3. Variable flexure-based fluid filter

    DOE Patents [OSTI]

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

    2007-03-13T23:59:59.000Z

    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.

  4. Variable area light reflecting assembly

    DOE Patents [OSTI]

    Howard, T.C.

    1986-12-23T23:59:59.000Z

    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.

  5. Variable area light reflecting assembly

    DOE Patents [OSTI]

    Howard, Thomas C. (Raleigh, NC)

    1986-01-01T23:59:59.000Z

    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.

  6. Radial Velocity Variability of Field Brown Dwarfs

    E-Print Network [OSTI]

    Prato, L; Rice, E L; McLean, I S; Kirkpatrick, J D; Burgasser, A J; Kim, S S

    2015-01-01T23:59:59.000Z

    We present paper six of the NIRSPEC Brown Dwarf Spectroscopic Survey, an analysis of multi-epoch, high-resolution (R~20,000) spectra of 25 field dwarf systems (3 late-type M dwarfs, 16 L dwarfs, and 6 T dwarfs) taken with the NIRSPEC infrared spectrograph at the W. M. Keck Observatory. With a radial velocity precision of ~2 km/s, we are sensitive to brown dwarf companions in orbits with periods of a few years or less given a mass ratio of 0.5 or greater. We do not detect any spectroscopic binary brown dwarfs in the sample. Given our target properties, and the frequency and cadence of observations, we use a Monte Carlo simulation to determine the detection probability of our sample. Even with a null detection result, our 1 sigma upper limit for very low mass binary frequency is 18%. Our targets included 7 known, wide brown dwarf binary systems. No significant radial velocity variability was measured in our multi-epoch observations of these systems, even for those pairs for which our data spanned a significant ...

  7. White dwarf masses in cataclysmic variables

    E-Print Network [OSTI]

    Wijnen, T P G; Schreiber, M R

    2015-01-01T23:59:59.000Z

    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...

  8. Variability of Disk Emission in Pre-Main Sequence and Related Stars. III. Exploring Structural Changes in the Pre-transitional Disk in HD 169142

    E-Print Network [OSTI]

    Wagner, Kevin R; Grady, Carol A; Whitney, Barbara A; Swearingen, Jeremy R; Champney, Elizabeth H; Johnson, Alexa N; Werren, Chelsea; Russell, Ray W; Schneider, Glenn H; Momose, Munetake; Muto, Takayuki; Inoue, Akio K; Lauroesch, James T; Brown, Alexander; Fukagawa, Misato; Currie, Thayne M; Hornbeck, Jeremy; Wisniewski, John P; Woodgate, Bruce E

    2014-01-01T23:59:59.000Z

    We present near-IR and far-UV observations of the pre-transitional (gapped) disk in HD 169142 using NASA's Infrared Telescope Facility and Hubble Space Telescope. The combination of our data along with existing data sets into the broadband spectral energy distribution reveals variability of up to 45% between ~1.5-10 {\\mu}m over a maximum timescale of 10 years. All observations known to us separate into two distinct states corresponding to a high near-IR state in the pre-2000 epoch and a low state in the post-2000 epoch, indicating activity within the <1 AU region of the disk. Through analysis of the Pa {\\beta} and Br {\\gamma} lines in our data we derive a mass accretion rate in May 2013 of (1.5 - 2.7) x 10^-9 Msun/yr. We present a theoretical modeling analysis of the disk in HD 169142 using Monte-Carlo radiative transfer simulation software to explore the conditions and perhaps signs of planetary formation in our collection of 24 years of observations. We find that shifting the outer edge (r = 0.3 AU) of t...

  9. IMPROVED VARIABLE STAR SEARCH IN LARGE PHOTOMETRIC DATA SETS: NEW VARIABLES IN CoRoT FIELD LRa02 DETECTED BY BEST II

    SciTech Connect (OSTI)

    Fruth, T.; Cabrera, J.; Csizmadia, Sz.; Eigmueller, P.; Erikson, A.; Kirste, S.; Pasternacki, T.; Rauer, H.; Titz-Weider, R. [Institut fuer Planetenforschung, Deutsches Zentrum fuer Luft- und Raumfahrt, Rutherfordstr. 2, 12489 Berlin (Germany); Kabath, P. [European Southern Observatory, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago 19 (Chile); Chini, R.; Lemke, R. [Astronomisches Institut, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); Murphy, M., E-mail: thomas.fruth@dlr.de [Depto. Fisica, Universidad Catolica del Norte, PO 1280, Antofagasta (Chile)

    2012-06-15T23:59:59.000Z

    The CoRoT field LRa02 has been observed with the Berlin Exoplanet Search Telescope II (BEST II) during the southern summer 2007/2008. A first analysis of stellar variability led to the publication of 345 newly discovered variable stars. Now, a deeper analysis of this data set was used to optimize the variability search procedure. Several methods and parameters have been tested in order to improve the selection process compared to the widely used J index for variability ranking. This paper describes an empirical approach to treat systematic trends in photometric data based upon the analysis of variance statistics that can significantly decrease the rate of false detections. Finally, the process of reanalysis and method improvement has virtually doubled the number of variable stars compared to the first analysis by Kabath et al. A supplementary catalog of 272 previously unknown periodic variables plus 52 stars with suspected variability is presented. Improved ephemerides are given for 19 known variables in the field. In addition, the BEST II results are compared with CoRoT data and its automatic variability classification.

  10. INTEGRAL observations of HER X-1

    E-Print Network [OSTI]

    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

    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.

  11. Variable Temperature STM/AFM | EMSL

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

    STMAFM Variable Temperature STMAFM EMSL's ultra-high vacuum, variable-temperature scanning probe microscope system, or UHV VT SPM, is a state-of-the-art surface science tool...

  12. Thermoacoustic tomography, variable sound speed Plamen Stefanov

    E-Print Network [OSTI]

    Stefanov, Plamen

    Thermoacoustic tomography, variable sound speed Plamen Stefanov Purdue University Based on a joint work with Gunther Uhlmann Plamen Stefanov (Purdue University ) Thermoacoustic tomography, variable sound speed 1 / 18 #12;Formulation Main Problem Thermoacoustic Tomography In thermoacoustic tomography

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

    SciTech Connect (OSTI)

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

    1999-01-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

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

    2007-01-11T23:59:59.000Z

    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.

  15. Periodic photometric variability of the brown dwarf Kelu-1

    E-Print Network [OSTI]

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

    2002-01-10T23:59:59.000Z

    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.

  16. S5 0716+714 : GeV variability study

    E-Print Network [OSTI]

    Rani, B; Lott, B; Fuhrmann, L; Zensus, J A

    2013-01-01T23:59:59.000Z

    The GeV observations by Fermi-LAT give us the opportunity to characterize the high-energy emission (100 MeV - 300 GeV) variability properties of the BL Lac object S5 0716+714. In this study, we performed flux and spectral analysis of more than 3 year long (August 2008 to April 2012) Fermi-LAT data of the source. During this period, the source exhibits two different modes of flux variability with characteristic timescales of ~75 and ~140 days, respectively. We also notice that the flux variations are characterized by a weak spectral hardening. The GeV spectrum of the source shows a clear deviation from a simple power law, and is better explained by a broken power law. Similar to other bright Fermi blazars, the break energy does not vary with the source flux during the different activity states. We discuss several possible scenarios to explain the observed spectral break.

  17. Variable frequency microwave furnace system

    DOE Patents [OSTI]

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

    1994-01-01T23:59:59.000Z

    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).

  18. Variable frequency microwave furnace system

    DOE Patents [OSTI]

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

    1994-06-14T23:59:59.000Z

    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.

  19. Fast singular value decomposition combined maximum entropy method for plasma tomography

    SciTech Connect (OSTI)

    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

    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.

  20. Atomic Collapse Observed

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

    Scientists Observe Atomic Collapse State Quantum Mechanics Prediction Confirmed in Graphene Using NERSC's Hopper April 26, 2013 | Tags: Hopper, Materials Science Contact: Linda...

  1. Hot Pot Field Observations

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

    Lane, Michael

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

  2. Hot Pot Field Observations

    SciTech Connect (OSTI)

    Lane, Michael

    2013-06-28T23:59:59.000Z

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

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

    SciTech Connect (OSTI)

    Byrne, Raymond Harry; Silva Monroy, Cesar Augusto.

    2012-12-01T23:59:59.000Z

    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.

  4. Broadband Spectra and Variability of BL Lacertae in 2000

    E-Print Network [OSTI]

    M. Boettcher; H. D. Aller; M. F. Aller; O. Mang; C. M. Raiteri; M. Ravasio; G. Tagliaferri; H. Teraesranta; M. Villata

    2002-03-21T23:59:59.000Z

    We have organized an extensive multiwavelength campaign on BL Lacertae in the second half of 2000. Simultaneous or quasi-simultaneous observations were taken at radio frequencies, in the optical - carried out by the WEBT collaboration -, in X-rays - using BeppoSAX and RXTE -, and at VHE gamma-rays with the CAT and HEGRA Cherenkov telescope facilities. In this paper, we are presenting first results from this campaign. The WEBT optical campaign achieved an unprecedented time coverage, virtually continuous over several 10 - 20 hour segments, and revealed intraday variability on time scales of ~ 1.5 hours. The X-ray observations of Nov. 1 - 2, 2000, revealed significant variability on similar time scales, and provided evidence for the synchrotron spectrum extending out to ~ 10 keV during that time. At higher energies, the onset of the hard power-law commonly observed in radio-loud quasars and radio-selected BL Lac objects is seen. From the energy-resolved X-ray variability patterns, we find evidence that electron cooling might not be dominated by one single radiation mechanism; rather, a combination of synchrotron and Compton cooling seems to be required.

  5. Broadband Spectra and Variability of BL Lacertae in 2000

    E-Print Network [OSTI]

    Böttcher, M; Aller, M F; Mang, O; Raiteri, C M; Ravasio, M; Tagliaferri, G; Teraesranta, H; Villata, M

    2002-01-01T23:59:59.000Z

    We have organized an extensive multiwavelength campaign on BL Lacertae in the second half of 2000. Simultaneous or quasi-simultaneous observations were taken at radio frequencies, in the optical - carried out by the WEBT collaboration -, in X-rays - using BeppoSAX and RXTE -, and at VHE gamma-rays with the CAT and HEGRA Cherenkov telescope facilities. In this paper, we are presenting first results from this campaign. The WEBT optical campaign achieved an unprecedented time coverage, virtually continuous over several 10 - 20 hour segments, and revealed intraday variability on time scales of ~ 1.5 hours. The X-ray observations of Nov. 1 - 2, 2000, revealed significant variability on similar time scales, and provided evidence for the synchrotron spectrum extending out to ~ 10 keV during that time. At higher energies, the onset of the hard power-law commonly observed in radio-loud quasars and radio-selected BL Lac objects is seen. From the energy-resolved X-ray variability patterns, we find evidence that electron...

  6. Photometric Variability in the CSTAR Field: Results From the 2008 Data Set

    E-Print Network [OSTI]

    Wang, Songhu; Zhou, Xu; Zhou, Ji-Lin; Fu, Jian-Ning; Yang, Ming; Liu, Huigen; Xie, Jiwei; Wang, Lifan; Wang, Lingzhi; Wittenmyer, R A; Ashley, M C B; Feng, Long-Long; Gong, Xuefei; Lawrence, J S; Liu, Qiang; Luong-Van, D M; Ma, Jun; Peng, Xiyan; Storey, J W V; Wu, Zhenyu; Yan, Jun; Yang, Huigen; Yang, Ji; Yuan, Xiangyan; Zhang, Tianmeng; Zhang, Xiaojia; Zhu, Zhenxi; Zou, Hu

    2015-01-01T23:59:59.000Z

    The Chinese Small Telescope ARray (CSTAR) is the first telescope facility built at Dome A, Antarctica. During the 2008 observing season, the installation provided long-baseline and high-cadence photometric observations in the i-band for 18,145 targets within 20 deg2 CSTAR field around the South Celestial Pole for the purpose of monitoring the astronomical observing quality of Dome A and detecting various types of photometric variability. Using sensitive and robust detection methods, we discover 274 potential variables from this data set, 83 of which are new discoveries. We characterize most of them, providing the periods, amplitudes and classes of variability. The catalog of all these variables is presented along with the discussion of their statistical properties.

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

    SciTech Connect (OSTI)

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

    2009-03-15T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  9. Maximum-Entropy Closures for Kinetic Theories of Neuronal Network Dynamics

    SciTech Connect (OSTI)

    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

    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.

  10. Maximum Entropy Models of Shortest Path and Outbreak Distributions in Networks

    E-Print Network [OSTI]

    Bauckhage, Christian; Hadiji, Fabian

    2015-01-01T23:59:59.000Z

    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.

  11. A Three-Decade Outburst of the LMC Luminous Blue Variable R127 Draws to a Close

    E-Print Network [OSTI]

    Nolan R. Walborn; Otmar Stahl; Roberto C. Gamen; Thomas Szeifert; Nidia I. Morrell; Nathan Smith; Ian D. Howarth; Roberta M. Humphreys; Howard E. Bond; Daniel J. Lennon

    2008-07-09T23:59:59.000Z

    The paradigmatic Luminous Blue Variable R127 in the Large Magellanic Cloud has been found in the intermediate, peculiar early-B state, and substantially fainter in visual light, signaling the final decline from its major outburst that began between 1978 and 1980. This transformation was detected in 2008 January, but archival data show that it began between early 2005 and early 2007. In fact, significant changes from the maximum, peculiar A-type spectrum, which was maintained from 1986 through 1998, had already begun the following year, coinciding with a steep drop in visual light. We show detailed correspondences between the spectrum and light, in which the decline mimics the rise. Moreover, these trends are not monotonic but are characterized by multiple spikes and dips, which may provide constraints on the unknown outburst mechanism. Intensive photometric and spectroscopic monitoring of R127 should now resume, to follow the decline presumably back to the quiescent Ofpe/WN9 state, in order to fully document the remainder of this unique observational opportunity.

  12. Power Counting to Better Jet Observables

    E-Print Network [OSTI]

    Andrew J. Larkoski; Ian Moult; Duff Neill

    2014-09-22T23:59:59.000Z

    Optimized jet substructure observables for identifying boosted topologies will play an essential role in maximizing the physics reach of the Large Hadron Collider. Ideally, the design of discriminating variables would be informed by analytic calculations in perturbative QCD. Unfortunately, explicit calculations are often not feasible due to the complexity of the observables used for discrimination, and so many validation studies rely heavily, and solely, on Monte Carlo. In this paper we show how methods based on the parametric power counting of the dynamics of QCD, familiar from effective theory analyses, can be used to design, understand, and make robust predictions for the behavior of jet substructure variables. As a concrete example, we apply power counting for discriminating boosted Z bosons from massive QCD jets using observables formed from the n-point energy correlation functions. We show that power counting alone gives a definite prediction for the observable that optimally separates the background-rich from the signal-rich regions of phase space. Power counting can also be used to understand effects of phase space cuts and the effect of contamination from pile-up, which we discuss. As these arguments rely only on the parametric scaling of QCD, the predictions from power counting must be reproduced by any Monte Carlo, which we verify using Pythia8 and Herwig++. We also use the example of quark versus gluon discrimination to demonstrate the limits of the power counting technique.

  13. Variable residence time vortex combustor

    DOE Patents [OSTI]

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

    1987-01-01T23:59:59.000Z

    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.

  14. Variable delivery, fixed displacement pump

    DOE Patents [OSTI]

    Sommars, Mark F. (Sparland, IL)

    2001-01-01T23:59:59.000Z

    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.

  15. Continuously variable focal length lens

    DOE Patents [OSTI]

    Adams, Bernhard W; Chollet, Matthieu C

    2013-12-17T23:59:59.000Z

    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.

  16. Variable ratio regenerative braking device

    DOE Patents [OSTI]

    Hoppie, Lyle O. (Birmingham, MI)

    1981-12-15T23:59:59.000Z

    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.

  17. Upper-ocean variability in Drake Passage and the Weddell Sea : Measuring the oceanic response to air-sea and ice-ocean interactions

    E-Print Network [OSTI]

    Stephenson, Gordon Ronald

    2012-01-01T23:59:59.000Z

    The influence of nonlinear mesoscale eddies on oceanicGlobal observations of nonlinear mesoscale eddies. Prog.Firing, E. , 2007: Mean jets, mesoscale variability and eddy

  18. 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

  19. Analysis and Optimization of Maximum Power Point Tracking Algorithms in the Presence of

    E-Print Network [OSTI]

    Odam, Kofi

    , Charles R. Sullivan, Senior Member, IEEE Abstract--This paper analyzes the effect of noise on sev- eral maximum power point tracking (MPPT) algorithms for photovoltaic systems. Noise is an essential of the signals, mitigating the noise. The effect of noise and other parameters on tracking performance

  20. Maximum Output Amplitude of Linear Systems for certain Input Constraints1

    E-Print Network [OSTI]

    Sontag, Eduardo

    of this input and calculates the maximum amplitude of the output. The solution of this problem is a necessary, Linear Sys- tems. 1 Introduction and Motivation Most practical control problems are dominated by hard bounds. Valves can only be operated between fully open and fully closed, pumps and compressors have

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

    E-Print Network [OSTI]

    Choi, Seungjin

    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

  2. Radiative Impacts on the Growth of Drops within Simulated Marine Stratocumulus. Part I: Maximum Solar Heating

    E-Print Network [OSTI]

    Harrington, Jerry Y.

    Radiative Impacts on the Growth of Drops within Simulated Marine Stratocumulus. Part I: Maximum Solar Heating CHRISTOPHER M. HARTMAN AND JERRY Y. HARRINGTON Department of Meteorology, The Pennsylvania November 2004) ABSTRACT The effects of solar heating and infrared cooling on the vapor depositional growth

  3. Maximum principle and bang-bang property of time optimal controls for Schrodinger type systems

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Maximum principle and bang-bang property of time optimal controls for Schr¨odinger type systems J conditions for the bang- bang property of optimal controls. The results are then applied to some systems-Bang property, Schr¨odinger equation 1 Introduction Time optimal control is a classical problem for linear

  4. Recursive maximum likelihood estimation for structural health monitoring: Kalman and particle filter implementations

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Recursive maximum likelihood estimation for structural health monitoring: Kalman and particle by a likelihood approach. In a first part the structural health monitoring problem is written in term of recursive al [6] in a more simple framework. Particle approximation for health monitoring was already proposed

  5. Maximum-Power-Point Tracking Method of Photovoltaic Power System Using Single Transducer

    E-Print Network [OSTI]

    Fujimoto, Hiroshi

    Maximum-Power-Point Tracking Method of Photovoltaic Power System Using Single Transducer Toshihiko) method of a photovoltaic power system with less transducer count. A unique feature of this method concern on an environmental issue since 1990's. Above all, a photovoltaic power generation system is one

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

    E-Print Network [OSTI]

    Kusiak, Andrew

    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

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

    E-Print Network [OSTI]

    Zweck, John

    Xi, T¨ulay 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

  8. Brayton Cycles: From the ...rst law, the maximum transfers for component SSSF control volumes are

    E-Print Network [OSTI]

    . For the simple reversible Brayton cycle of given pressure ratio rp $ (p2=p1) = (p3=p4) [compare Example 9.4, pp is higher than 1 r (2=7) . For the ideal regenerator, the thermal e¢ ciency approaches the Carnot-cycle eBrayton Cycles: From the ...rst law, the maximum transfers for component SSSF control volumes are w

  9. Maximum Likelihood Estimation of Mixture Densities for Binned and Truncated Multivariate

    E-Print Network [OSTI]

    Smyth, Padhraic

    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

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

    E-Print Network [OSTI]

    Turro, Nicholas J.

    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

  11. Vision Research 40 (2000) 11571165 Local luminance factors that determine the maximum disparity for

    E-Print Network [OSTI]

    Kingdom, Frederick A. A.

    2000-01-01T23:59:59.000Z

    Vision Research 40 (2000) 1157­1165 Local luminance factors that determine the maximum disparity dense arrays of micropatterns, whose luminance characteristics were manipulated. In Experiment 1, we with luminance spatial frequency and with Gabor size, but was constant for a constant bandwidth (frequency times

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

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    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

  13. Learning with MaximumEntropy Distributions \\Lambda Yishay Mansour Mariano Schain

    E-Print Network [OSTI]

    Mansour, Yishay

    Learning with Maximum­Entropy Distributions \\Lambda Yishay Mansour Mariano Schain Computer Science Dept. Tel­Aviv University fmansour,marianog@math.tau.ac.il Abstract We are interested in distributions which are de­ rived as a maximumentropy distribution given a set of constraints. More specifically, we

  14. A Global Maximum Power Point Tracking Method for PV Module Integrated Converters

    E-Print Network [OSTI]

    Liberzon, Daniel

    with large arrays of series-connected PV mod- ules connected to a central inverter. Figure 1(a) depicts, it is conceivable that these systems do not extract the maximum possible power from the PV array when individual PV to partial shading. In such systems, power electronics circuits are integrated directly with PV modules

  15. Department of Mechanical Engineering Spring 2013 Maximum Allowable Gasket Seating Surface Degradation

    E-Print Network [OSTI]

    Demirel, Melik C.

    Degradation Overview Westinghouse applies a conservative approach when evaluating degradation on a gasket evaluation. The team was tasked with collecting this data to determine when degradation endangers the pressure seal. Objectives The team's objectives were to determine the maximum degradation which the gasket

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

    E-Print Network [OSTI]

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

    2002-01-01T23:59:59.000Z

    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...

  17. Bayesian Data and Channel Joint Maximum-Likelihood Based Error Correction in Wireless Sensor Networks

    E-Print Network [OSTI]

    Jagannatham, Aditya K.

    in wireless sensor networks (WSN). The proposed algo- rithm employs the temporal correlation of the narrowband Wireless Sensor Network (WSN), Likelihood, Sphere De- coder 1. INTRODUCTION Wireless Sensor Networks (WSNBayesian Data and Channel Joint Maximum-Likelihood Based Error Correction in Wireless Sensor

  18. Maximum-Lifetime Multi-Channel Routing in Wireless Sensor Networks

    E-Print Network [OSTI]

    Nasipuri, Asis

    Maximum-Lifetime Multi-Channel Routing in Wireless Sensor Networks Amitangshu Pal and Asis Nasipuri and routing problem in multi-channel wireless sensor networks for maximizing the worst case network lifetime solution for the problem. Keywords: Wireless sensor networks, multi-channel rout- ing, distributed

  19. 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

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

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    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

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

    E-Print Network [OSTI]

    Lorenz, Ralph D.

    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

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

    E-Print Network [OSTI]

    Jackson, Robert B.

    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

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

    E-Print Network [OSTI]

    Odam, Kofi

    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

  4. PHYSICAL REVIEW E 86, 041144 (2012) Efficiency at maximum power for classical particle transport

    E-Print Network [OSTI]

    Lindenberg, Katja

    2012-01-01T23:59:59.000Z

    PHYSICAL REVIEW E 86, 041144 (2012) Efficiency at maximum power for classical particle transport transport. DOI: 10.1103/PhysRevE.86.041144 PACS number(s): 05.70.Ln, 05.40.-a, 05.20.-y I. INTRODUCTION Over, operating between a hot and cold bath at temperatures T (1) and T (2) , respectively, possesses universal

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

    E-Print Network [OSTI]

    Katul, Gabriel

    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

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

    E-Print Network [OSTI]

    Liberzon, Daniel

    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

  7. An Analysis of the Maximum Drawdown Risk Malik Magdon-Ismail

    E-Print Network [OSTI]

    Magdon-Ismail, Malik

    Engineering Cairo University Giza, Egypt. amir@alumni.caltech.edu Introduction. The maximum cumulative loss to the Calmar ratio is the Sterling ratio, Sterling(T) = Return over [0,T ] MDD over [0,T ]-10% , and our discussion applies equally well to the Sterling ratio. 1 #12;primarily due to a lack of an analytical

  8. An Analysis of the Maximum Drawdown Risk Malik MagdonIsmail

    E-Print Network [OSTI]

    Magdon-Ismail, Malik

    Engineering Cairo University Giza, Egypt. amir@alumni.caltech.edu Introduction. The maximum cumulative loss is not prevalent 1 Similar to the Calmar ratio is the Sterling ratio, Sterling(T ) = Return over [0,T ] MDD over [0,T ]-10% , and our discussion applies equally well to the Sterling ratio. 1 #12; primarily due

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

    E-Print Network [OSTI]

    Dominik Nickel

    2006-07-20T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Nasser, Hassan

    2014-01-01T23:59:59.000Z

    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.

  11. 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

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

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Masahiro Imachi; Yasuhiko Shinno; Hiroshi Yoneyama

    2007-02-09T23:59:59.000Z

    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.

  14. Relating maximum airway dilation and subsequent reconstriction to reactivity in human lungs

    E-Print Network [OSTI]

    Lutchen, Kenneth

    Relating maximum airway dilation and subsequent reconstriction to reactivity in human lungs Lauren in human lungs. J Appl Physiol 96: 1808­1814, 2004. First published February 6, 2004; 10.1152/japplphysiol reactivity in healthy lungs by prohibiting DI for an extended period. The present study had two goals. First

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

    E-Print Network [OSTI]

    Winter, Lisa M

    2015-01-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2011-08-15T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2011-08-16T23:59:59.000Z

    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.

  18. NERC Presentation: Accommodating High Levels of Variable Generation...

    Office of Environmental Management (EM)

    of variable electricity eneration. Variable resources are types of electric power generation that rely on an uncontrolled, "variable" fuel (e.g. wind, sunlight, waves, tidal...

  19. AUTOMATIC VARIABLE VENTILATION CONTROL SYSTEMS BASED ON AIR QUALITY DETECTION

    E-Print Network [OSTI]

    Turiel, Isaac

    2011-01-01T23:59:59.000Z

    ~saon Automatic Variable Ventilation Control Systems Based79-3 Automatic variable ventilation control systems based onof automatic variable ventilation control systems, result in

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

    SciTech Connect (OSTI)

    Hiergesell, R

    2005-04-01T23:59:59.000Z

    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.

  1. Variability in the super-Earth 55 Cnc e

    E-Print Network [OSTI]

    Demory, Brice-Olivier; Madhusudhan, Nikku; Queloz, Didier

    2015-01-01T23:59:59.000Z

    Considerable progress has been made in recent years in observations of atmospheric signatures of giant exoplanets, but processes in rocky exoplanets remain largely unknown due to major challenges in observing small planets. Numerous efforts to observe spectra of super-Earths, exoplanets with masses of 1-10 Earth masses, have thus far revealed only featureless spectra. In this paper we report a 4-$\\sigma$ detection of variability in the dayside thermal emission from the transiting super-Earth 55 Cancri e. Dedicated space-based monitoring of the planet in the mid-infrared over eight eclipses revealed the thermal emission from its dayside atmosphere varying by a factor 3.7 between 2012 and 2013. The amplitude and trend of the variability are not explained by potential influence of star spots or by local thermal or compositional changes in the atmosphere over the short span of the observations. The possibility of large scale surface activity due to strong tidal interactions possibly similar to Io, or the presence...

  2. Liquid crystal variable retarders in atomic scattering

    SciTech Connect (OSTI)

    Furst, J.E.; Yu, D.H.; Hayes, P.A.; DSouza, C.M.; Williams, J.F. [Physics Department, Centre for Atomic, Molecular, and Surface Physics, The University of Western Australia, Nedlands. WA. 6907 (Australia)] [Physics Department, Centre for Atomic, Molecular, and Surface Physics, The University of Western Australia, Nedlands. WA. 6907 (Australia)

    1996-11-01T23:59:59.000Z

    The applications of liquid crystal variable retarders in the production of spin-polarized electrons and in the determination of the polarization of optical radiation from atoms excited by polarized electrons are discussed. The advantages of using liquid crystal variable retarders in the measurement of Stokes parameters are insensitivity to the incident photon direction, large transmission diameter, variable retardation over large wavelength range without mechanical movement, and {ital in} {ital situ} calibration. {copyright} {ital 1996 American Institute of Physics.}

  3. Eccentric crank variable compression ratio mechanism

    DOE Patents [OSTI]

    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

    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.

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

    E-Print Network [OSTI]

    Kensuke Imanishi; Masahiro Tsujimoto; Katsuji Koyama

    2002-02-15T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  6. Variable-Period Undulators For Synchrotron Radiation

    DOE Patents [OSTI]

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

    2005-02-22T23:59:59.000Z

    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.

  7. Variable Temperature UHV STM/AFM | EMSL

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

    Temperature UHV STMAFM The Omicron variable temperature ultra-high vacuum (UHV) scanning tunneling microscope (VTSTM) is designed to study the structure of both clean and...

  8. Optimization Online - Global Optimization via Slack Variables

    E-Print Network [OSTI]

    Isaac Siwale

    2014-08-01T23:59:59.000Z

    Aug 1, 2014 ... Citation: Siwale, I. (2014). Global optimization via slack variables. Technical Report No. RD-16-2013, London: Apex Research Ltd. Download: ...

  9. Variable Stars in the Field of the Globular Cluster NGC 3201

    E-Print Network [OSTI]

    Kaspar von Braun; Mario Mateo

    2001-09-25T23:59:59.000Z

    We report on the discovery and analysis of 14 short-period variable stars in the field of the southern globular cluster NGC 3201, located within roughly two magnitudes on either side of the main-sequence turnoff. 11 of these variable stars are eclipsing binaries, one is an RR Lyrae, and two are thus far unclassified systems. Among the eclipsing binary stars, nine are of the W Ursa Majoris (W UMa) type, one an Algol (EA) system, and one a detached system. Using spectroscopic follow-up observations as well as analysis of the variables' locations in the color-magnitude diagram of the cluster, we find that only one variable star (a W UMa type blue straggler) is actually a member of NGC 3201. We present the phased photometry lightcurves for all the variable star systems as well as their locations in the field-of-view and in the color-magnitude diagram.

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

    SciTech Connect (OSTI)

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

    2006-01-01T23:59:59.000Z

    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.

  11. Observing Massive Galaxy Formation

    E-Print Network [OSTI]

    Christopher J. Conselice

    2002-12-20T23:59:59.000Z

    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.

  12. Air Observe System

    E-Print Network [OSTI]

    Alexander Bolonkin

    2007-01-10T23:59:59.000Z

    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.

  13. Self-adjoint Lyapunov variables, temporal ordering and irreversible representations of Schroedinger evolution

    E-Print Network [OSTI]

    Y. Strauss

    2009-09-24T23:59:59.000Z

    In non relativistic quantum mechanics time enters as a parameter in the Schroedinger equation. However, there are various situations where the need arises to view time as a dynamical variable. In this paper we consider the dynamical role of time through the construction of a Lyapunov variable - i.e., a self-adjoint quantum observable whose expectation value varies monotonically as time increases. It is shown, in a constructive way, that a certain class of models admit a Lyapunov variable and that the existence of a Lyapunov variable implies the existence of a transformation mapping the original quantum mechanical problem to an equivalent irreversible representation. In addition, it is proved that in the irreversible representation there exists a natural time ordering observable splitting the Hilbert space at each t>0 into past and future subspaces.

  14. Self-adjoint Lyapunov variables, temporal ordering, and irreversible representations of Schroedinger evolution

    SciTech Connect (OSTI)

    Strauss, Y. [Einstein Institute of Mathematics, Hebrew University of Jerusalem, Jerusalem, 91904 (Israel)

    2010-02-15T23:59:59.000Z

    In nonrelativistic quantum mechanics time enters as a parameter in the Schroedinger equation. However, there are various situations where the need arises to view time as a dynamical variable. In this paper we consider the dynamical role of time through the construction of a Lyapunov variable - i.e., a self-adjoint quantum observable whose expectation value varies monotonically as time increases. It is shown, in a constructive way, that a certain class of models admits a Lyapunov variable and that the existence of a Lyapunov variable implies the existence of a transformation mapping the original quantum mechanical problem to an equivalent irreversible representation. In addition, it is proven that in the irreversible representation there exists a natural time ordering observable splitting the Hilbert space at each t>0 into past and future subspaces.

  15. Three dimensional winds: A maximum cross-correlation application to elastic lidar data

    SciTech Connect (OSTI)

    Buttler, W.T.

    1996-05-01T23:59:59.000Z

    Maximum cross-correlation techniques have been used with satellite data to estimate winds and sea surface velocities for several years. Los Alamos National Laboratory (LANL) is currently using a variation of the basic maximum cross-correlation technique, coupled with a deterministic application of a vector median filter, to measure transverse winds as a function of range and altitude from incoherent elastic backscatter lidar (light detection and ranging) data taken throughout large volumes within the atmospheric boundary layer. Hourly representations of three-dimensional wind fields, derived from elastic lidar data taken during an air-quality study performed in a region of complex terrain near Sunland Park, New Mexico, are presented and compared with results from an Environmental Protection Agency (EPA) approved laser doppler velocimeter. The wind fields showed persistent large scale eddies as well as general terrain-following winds in the Rio Grande valley.

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

    E-Print Network [OSTI]

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

    2001-01-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Klaus Strobel; Manfred K. Weigel

    2000-12-14T23:59:59.000Z

    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.

  18. Evaluation of Maximum Radionuclide Groundwater Concentrations for Basement Fill Model. Zion Station Restoration Project

    SciTech Connect (OSTI)

    Sullivan, Terry [Brookhaven National Lab. (BNL), Upton, NY (United States). Biological, Environmental, and Climate Sciences Dept.

    2014-12-02T23:59:59.000Z

    ZionSolutions is in the process of decommissioning the Zion Nuclear Power Plant in order to establish a new water treatment plant. There is some residual radioactive particles from the plant which need to be brought down to levels so an individual who receives water from the new treatment plant does not receive a radioactive dose in excess of 25 mrem/y?¹. The objectives of this report are: (a) To present a simplified conceptual model for release from the buildings with residual subsurface structures that can be used to provide an upper bound on contaminant concentrations in the fill material; (b) Provide maximum water concentrations and the corresponding amount of mass sorbed to the solid fill material that could occur in each building for use in dose assessment calculations; (c) Estimate the maximum concentration in a well located outside of the fill material; and (d) Perform a sensitivity analysis of key parameters.

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

    SciTech Connect (OSTI)

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

    2009-09-04T23:59:59.000Z

    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.

  20. Constraints on AGN accretion disc viscosity derived from continuum variability

    E-Print Network [OSTI]

    Rhaana L. C. Starling; Aneta Siemiginowska; Phil Uttley; Roberto Soria

    2003-09-10T23:59:59.000Z

    We estimate a value of the viscosity parameter in AGN accretion discs for the PG quasar sample. We assume that optical variability on time-scales of months to years is caused by local instabilities in the inner accretion disc. Comparing the observed variability time-scales to the thermal time-scales of alpha-disc models we obtain constraints on the viscosity parameter for the sample. We find that, at a given L/L_Edd, the entire sample is consistent with a single value of the viscosity parameter, alpha. We obtain constraints of 0.01 < alpha < 0.03 for 0.01 < L/L_Edd < 1.0. This narrow range suggests that these AGN are all seen in a single state, with a correspondingly narrow spread of black hole masses or accretion rates. The value of alpha we derive is consistent with predictions by current simulation s in which MHD turbulence is the primary viscosity mechanism.

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

    SciTech Connect (OSTI)

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

    2014-08-15T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    UMEDA, T.; MATSUFURU, H.

    2005-07-25T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    M. Oevers; C. Davies; J. Shigemitsu

    2000-09-22T23:59:59.000Z

    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.

  4. Maximum entropy deconvolution of resonant inelastic x-ray scattering spectra

    E-Print Network [OSTI]

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

    2012-02-10T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Takashi Umeda; Hideo Matsufuru

    2005-10-05T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Johnston, Walter Edward

    1965-01-01T23:59:59.000Z

    *) )() yx V = y* ? ie x* yx 2 n 2 2 n 21 Z (yp-y*) -g ?Z (x -x") J/n, yx rl l n x* Q x(f ~ y fyiq) * n& ', n)(j Thus the estimates of p, tT, and p are obtained by solving (B. 4) 2 y y These estimates are (s. s) m y))) +P (x x*) Y yx 2 rl q /2 *2... factors, which are either fixed or follow a multinormal distribution, employed in the n repetitions of the experiment, B = a (p x 1) matrix of unknown partial regression coeffictents to be estimated. The approach to the problem of missing data...

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

    E-Print Network [OSTI]

    Boyer, Edmond

    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

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

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    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

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

    E-Print Network [OSTI]

    Cycle · ENSO Footprint(s) · Recent Climate Trends · Outlook to Mid-21st Century Range Mgmt. Symposium, Denver, 10 February 10 #12;Average Annual Precipitation for the Western U.S. Based on PRISM OSU/WRCC #12 eruptions, this means more energy input - And higher global temperatures #12;Temperature Widespread warming

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

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    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

  11. Nonparametric Density Estimation for Stochastic Optimization with an Observable State Variable

    E-Print Network [OSTI]

    Blei, David M.

    Princeton, NJ 08544 powell@princeton.edu David M. Blei Princeton University Princeton, NJ 08544 blei

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

    E-Print Network [OSTI]

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

    2014-06-24T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    cuando El Niño prevalece, el norte de México es también másel sur es más seco. Cuando el Atlántico norte tropical secalienta, el norte de México se caracteriza por ser más seco

  14. Variability in the Initial Costs of Care and One-Year Outcomes of Observation Services

    E-Print Network [OSTI]

    Abbass, Ibrahim

    2015-01-01T23:59:59.000Z

    an ED episode across all OUs was $5,328 (5 th percentile=$3,016, 95 th percentile=$10,113), and after adjusting for

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

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    invernadero y del calentamiento global. Sin embargo, losa consecuencia del calentamiento global y que la sequía ya

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

    E-Print Network [OSTI]

    Detwiler, Russell

    -water reactions. For example, subsurface CO2 sequestration in depleted oil and gas reservoirs or deep saline., 2003; Gherardi et al., 2007]. Furthermore, in deep reservoirs, mineral dissolution is coupled

  17. Nonparametric Density Estimation for Stochastic Optimization with an Observable State Variable

    E-Print Network [OSTI]

    Powell, Warren B.

    -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

  18. Variability in the Initial Costs of Care and One-Year Outcomes of Observation Services

    E-Print Network [OSTI]

    Abbass, Ibrahim

    2015-01-01T23:59:59.000Z

    costs and outcomes imposed by the prognostic characteristics of different diseases. METHODS Study Design and Data

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

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

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

  20. Variability in the Initial Costs of Care and One-Year Outcomes of Observation Services

    E-Print Network [OSTI]

    Abbass, Ibrahim

    2015-01-01T23:59:59.000Z

    Department of Health and Human Services, Office of InspectorServices Ibrahim Abbass, RPh, PhD University of Texas School of Public Health,

  1. Observed Interannual Variability of the Florida Current: Wind Forcing and the North Atlantic Oscillation

    E-Print Network [OSTI]

    Oscillation PEDRO N. DINEZIO AND LEWIS J. GRAMER Cooperative Institute for Marine and Atmospheric Studies estimates of the total volume transport of seawater through the Straits of Florida (Larsen and Sanford 1985; Baringer and Larsen 2001). This cable record has been used to study seasonal variations in FC transport

  2. Observed Interannual Variability of the Florida1 Current: Wind Forcing and the North Atlantic2

    E-Print Network [OSTI]

    Miami, University of

    School of Marine and Atmospheric Science, University of Miami, Miami,8 Florida9 10 Lewis J. Gramer11 to produce daily estimates of the total volume transport of seawater through the8 Straits of Florida (Larsen and Sanford, 1985; Baringer and Larsen, 2001).9 This cable record has been used to study seasonal variations

  3. 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]

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

    2010-01-01T23:59:59.000Z

    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

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

    SciTech Connect (OSTI)

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

    2012-03-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Jorick S. Vink; Alex de Koter

    2002-07-15T23:59:59.000Z

    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.

  7. Variable Speed Pumping for Level Control 

    E-Print Network [OSTI]

    Vasel, M.

    1982-01-01T23:59:59.000Z

    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...

  8. THE MULTI-USE STEINEL VARIABLE TEMPERATURE

    E-Print Network [OSTI]

    Kleinfeld, David

    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

  9. THE MULTI-USE STEINEL VARIABLE TEMPERATURE

    E-Print Network [OSTI]

    Kleinfeld, David

    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

  10. Solar Dynamics Observatory/ Extreme Ultraviolet Variability Experiment

    E-Print Network [OSTI]

    Mojzsis, Stephen J.

    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

  11. Boosting Search with Variable Elimination. ? Javier Larrosa

    E-Print Network [OSTI]

    Dechter, Rina

    Boosting Search with Variable Elimination. ? Javier Larrosa Dep. Llenguatges i Sistemes Inform#12ElimSearchS;k, a hybrid meta- algorithm that combines search and variable elimination. The param- eter S names from the constraint graph. We also provide experimental evidence that the hybrid algorithm can

  12. Boosting Search with Variable Elimination. ? Javier Larrosa

    E-Print Network [OSTI]

    Dechter, Rina

    Boosting Search with Variable Elimination. ? Javier Larrosa Dep. Llenguatges i Sistemes Inform of variables, reduces the search tree size. In this paper we introduce VarElimSearch(S;k), a hybrid meta the constraint graph. We also provide experimental evidence that the hybrid algorithm can outperform state

  13. Variable Speed Pumping for Level Control

    E-Print Network [OSTI]

    Vasel, M.

    1982-01-01T23:59:59.000Z

    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...

  14. 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

  15. 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

  16. Global Warming Observations

    E-Print Network [OSTI]

    Schofield, Jeremy

    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

  17. 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

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

    SciTech Connect (OSTI)

    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

    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.

  19. Infrared Colors and Variability of Evolved Stars from COBE DIRBE Data

    E-Print Network [OSTI]

    Beverly J. Smith

    2003-06-20T23:59:59.000Z

    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.

  20. Observationally based assessment of polar amplification of global warming

    E-Print Network [OSTI]

    Bhatt, Uma

    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

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

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Almog, Assaf

    2014-01-01T23:59:59.000Z

    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...

  3. Observational Mishaps - a Database

    E-Print Network [OSTI]

    Kaspar von Braun; Kristin Chiboucas; Denise Hurley-Keller

    1999-06-11T23:59:59.000Z

    We present a World-Wide-Web-accessible database of astronomical images which suffer from a variety of observational problems, ranging from common occurences, such as dust grains on filters and/or the dewar window, to more exotic phenomena, such as loss of primary mirror support due to the deflation of the support airbags. Apart from its educational usefulness, the purpose of this database is to assist astronomers in diagnosing and treating errant images at the telescope, thus saving valuable telescope time. Every observational mishap contained in this on-line catalog is presented in the form of a GIF image, a brief explanation of the problem, and, when possible, a suggestion for improving the image quality.

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

    SciTech Connect (OSTI)

    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

    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.

  5. Cosmological perturbations of a perfect fluid and noncommutative variables

    SciTech Connect (OSTI)

    De Felice, Antonio; Gerard, Jean-Marc; Suyama, Teruaki [Centre for Particle Physics and Phenomenology (CP3), Universite catholique de Louvain, Chemin du Cyclotron 2, B-1348 Louvain-la-Neuve (Belgium)

    2010-03-15T23:59:59.000Z

    We describe the linear cosmological perturbations of a perfect fluid at the level of an action, providing thus an alternative to the standard approach based only on the equations of motion. This action is suited not only to perfect fluids with a barotropic equation of state, but also to those for which the pressure depends on two thermodynamical variables. By quantizing the system we find that (1) some perturbation fields exhibit a noncommutativity quite analogous to the one observed for a charged particle moving in a strong magnetic field, (2) local curvature and pressure perturbations cannot be measured simultaneously, (3) ghosts appear if the null energy condition is violated.

  6. A search for rapid optical variability in radio-quiet quasars

    E-Print Network [OSTI]

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

    1998-03-09T23:59:59.000Z

    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.

  7. Dimensional variability of production steel castings

    SciTech Connect (OSTI)

    Peters, F.E.; Risteu, J.W.; Vaupel, W.G.; DeMeter, E.C.; Voigt, R.C.

    1994-12-31T23:59:59.000Z

    Work is ongoing to characterize the dimensional variability of steel casting features. Data are being collected from castings produced at representative Steel Founders` Society of America foundries. Initial results based on more than 12,500 production casting feature measurements are presented for carbon and low alloy steel castings produced in green sand, no-bake, and shell molds. A comprehensive database of casting, pattern, and feature variables has been developed so that the influence of the variables on dimensional variability can be determined. Measurement system analysis is conducted to insure that large measurement error is not reported as dimensional variability. Results indicate that the dimensional variability of production casting features is less than indicated in current US (SFSA) and international (ISO) standards. Feature length, casting weight, parting line and molding process all strongly influence dimensional variability. Corresponding pattern measurements indicate that the actual shrinkage amount for casting features varies considerably. This variation in shrinkage will strongly influence the ability of the foundry to satisfy customer dimensional requirements.

  8. Performance of twist-coupled blades on variable speed rotors

    SciTech Connect (OSTI)

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

    1999-12-07T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Chen, Sheng

    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

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

    E-Print Network [OSTI]

    Mitchell, Richard

    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

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

    E-Print Network [OSTI]

    Chapman, Patrick

    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

  12. Analysis of two basic variables of timeout 

    E-Print Network [OSTI]

    Zella, William Francis

    1974-01-01T23:59:59.000Z

    ANALYSIS OF TWO BASIC VARIABLES OF TIMEOUT A Thesis WILLIAM FRANCIS ZELLA Submitted to the Graduate College of Texas AaM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August l974 Major Subjects... Psychology ANALYSI QF TWQ BASIC VARIABLES CF TINEQU '. A Thesis V/ILLIAM FRANCIS ZELLA Approved as to s+yle and content bye Chairman of Commi, ee Head of De artment) (Membe Member) Member ABSTRACT Analysis of Two Basic Variables of Timeout. (August...

  13. Free kick instead of cross-validation in maximum-likelihood refinement of macromolecular crystal structures

    SciTech Connect (OSTI)

    Pražnikar, Jure [Institute Jožef Stefan, Jamova 39, 1000 Ljubljana (Slovenia); University of Primorska, (Slovenia); Turk, Dušan, E-mail: dusan.turk@ijs.si [Institute Jožef Stefan, Jamova 39, 1000 Ljubljana (Slovenia); Center of Excellence for Integrated Approaches in Chemistry and Biology of Proteins, (Slovenia)

    2014-12-01T23:59:59.000Z

    The maximum-likelihood free-kick target, which calculates model error estimates from the work set and a randomly displaced model, proved superior in the accuracy and consistency of refinement of crystal structures compared with the maximum-likelihood cross-validation target, which calculates error estimates from the test set and the unperturbed model. The refinement of a molecular model is a computational procedure by which the atomic model is fitted to the diffraction data. The commonly used target in the refinement of macromolecular structures is the maximum-likelihood (ML) function, which relies on the assessment of model errors. The current ML functions rely on cross-validation. They utilize phase-error estimates that are calculated from a small fraction of diffraction data, called the test set, that are not used to fit the model. An approach has been developed that uses the work set to calculate the phase-error estimates in the ML refinement from simulating the model errors via the random displacement of atomic coordinates. It is called ML free-kick refinement as it uses the ML formulation of the target function and is based on the idea of freeing the model from the model bias imposed by the chemical energy restraints used in refinement. This approach for the calculation of error estimates is superior to the cross-validation approach: it reduces the phase error and increases the accuracy of molecular models, is more robust, provides clearer maps and may use a smaller portion of data for the test set for the calculation of R{sub free} or may leave it out completely.

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

    SciTech Connect (OSTI)

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

    2014-09-01T23:59:59.000Z

    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.

  15. Dynamics of multi-modes maximum entangled coherent state over amplitude damping channel

    E-Print Network [OSTI]

    A. El Allati; Y. Hassouni; N. Metwally

    2012-02-18T23:59:59.000Z

    The dynamics of maximum entangled coherent state travels through an amplitude damping channel is investigated. For small values of the transmissivity rate the travelling state is very fragile to this noise channel, where it suffers from the phase flip error with high probability. The entanglement decays smoothly for larger values of the transmissivity rate and speedily for smaller values of this rate. As the number of modes increases, the travelling state over this noise channel loses its entanglement hastily. The odd and even states vanish at the same value of the field intensity.

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

    E-Print Network [OSTI]

    G. G. Amosov

    2006-08-10T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Cao, Cheng

    2012-07-16T23:59:59.000Z

    programming duality. We de ne a new problem called Non-collinear Packing Problem (NPP) as the following: De nition B.1. Non-collinear Packing Problem Given a set P of n points on the Euclidean plane R2, nd a maximum subset S P of non-collinear points, i....e. any three points are not collinear. Before proving the duality between NPP and LCP, we need to show how to formulate both problems to linear programming. To formulate the form of linear pro- gramming for instances of LCP and NNP, we use a few...

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

    E-Print Network [OSTI]

    M. Imachi; Y. Shinno; H. Yoneyama

    2003-09-22T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Philipp Gubler; Kenji Morita; Makoto Oka

    2011-08-30T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    H. Rudolf Fiebig

    2002-10-31T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Chris Allton; Danielle Blythe; Jonathan Clowser

    2002-04-26T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2007-01-15T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    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. Yoshié

    2001-10-16T23:59:59.000Z

    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.

  4. Observed Feedback between Winter Sea Ice and the North Atlantic Oscillation

    E-Print Network [OSTI]

    Strong, Courtenay; Magnusdottir, Gudrun; Stern, Hal

    2009-01-01T23:59:59.000Z

    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

  5. Variability in Measured Space Temperatures in 60 Homes

    SciTech Connect (OSTI)

    Roberts, D.; Lay, K.

    2013-03-01T23:59:59.000Z

    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.

  6. ARM Observations Projected

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041cloth DocumentationProducts (VAP) VAP Update Information on new, existing, andObservations Projected

  7. 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for RenewableSpeeding accessSpeeding access(SC)Gas and OilPhaseObservation ofEdge

  8. VARIABLE WINDS AND DUST FORMATION IN R CORONAE BOREALIS STARS

    SciTech Connect (OSTI)

    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

    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.

  9. UselessVariable Elimination Olin Shivers

    E-Print Network [OSTI]

    Shivers, Olin

    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

  10. Continuously-Variable Series-Elastic Actuator

    E-Print Network [OSTI]

    Mooney, Luke M.

    Actuator efficiency is an important factor in the design of powered leg prostheses, orthoses, exoskeletons, and legged robots. A continuously-variable series-elastic actuator (CV-SEA) is presented as an efficient actuator ...

  11. Utility Variable Generation Integration Group Fall Technical...

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

    15, 2014 9:00AM CDT to October 17, 2014 3:00PM CDT The Utility Variable Generation Integration Group (UVIG) Fall Technical Workshop in San Antonio, Texas will provide attendees...

  12. Variable volume architecture : expanding the boundary

    E-Print Network [OSTI]

    Saheba, Asheshh (Asheshh Mohit), 1972-

    2001-01-01T23:59:59.000Z

    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. ...

  13. The Cloud Computing and Other Variables

    E-Print Network [OSTI]

    Borjon-Kubota, Martha Estela

    2011-01-01T23:59:59.000Z

    12. Fragments in Six 13. Cloud Computing 14. Phase 15.Note 48. Devoured vi Cloud Computing and other Variables I.moment. Lasts hours. Cloud Computing Just there Over the

  14. Observing the Inflationary Reheating

    E-Print Network [OSTI]

    Jerome Martin; Christophe Ringeval; Vincent Vennin

    2014-10-29T23:59:59.000Z

    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.

  15. Ashtekar's New Variables and Positive Energy

    E-Print Network [OSTI]

    James M. Nester; Roh-Suan Tung; Yuan Zhong Zhang

    1994-01-07T23:59:59.000Z

    We discuss earlier unsuccessful attempts to formulate a positive gravitational energy proof in terms of the New Variables of Ashtekar. We also point out the difficulties of a Witten spinor type proof. We then use the special orthonormal frame gauge conditions to obtain a locally positive expression for the New Variables Hamiltonian and thereby a ``localization'' of gravitational energy as well as a positive energy proof.

  16. HVAC's Variable Refrigerant Flow (VRF) Technology

    E-Print Network [OSTI]

    Jones, S.

    2012-01-01T23:59:59.000Z

    1 Comfort by Design Steve Jones Commercial Sales Manager for Mitsubishi Southwest Business Unit HVAC?s Variable Refrigerant Flow (VRF) Technology HVAC Industry Overview HVAC Market Dollar Volume $18 Billion Source:;NABH Research... Moveable Ductless 5 VRF Technology Overview 6 What is VRF Technology? Variable Refrigerant Flow More Comfort, Less Energy Usage 8 INVERTER-driven Compressor Time R oo m T em pe ra tur e ? Enables capacity operation as low as 4% ? Sizing...

  17. OH Maser Observations of Planetary Nebulae Precursors

    E-Print Network [OSTI]

    R. M. Deacon; J. M. Chapman; A. J. Green

    2004-06-08T23:59:59.000Z

    We present OH maser observations at 1612, 1665, 1667, and 1720 MHz for 86 post-asymptotic giant branch (post-AGB) stars selected from a survey of 1612 MHz maser sources in the Galactic Plane. The observations were taken with the Parkes Telescope and the Australia Telescope Compact Array between 2002 September and 2003 August. Post-AGB stars are the precursors to planetary nebulae, the diverse morphological range of which is unexplained. The maser observations were taken to investigate the onset and incidence of wind asymmetries during the post-AGB phase. We re-detected all 86 sources at 1612 MHz while 27 sources were detected at 1665 and 45 at 1667 MHz. One source was re-detected at 1720 MHz. We present a classification scheme for the maser profiles and show that 25% of sources in our sample are likely to have asymmetric or bipolar outflows. From a comparison of the maser and far-infrared properties we find that there is a likely trend in the shape of the maser profiles with some sources evolving from double-peaked to irregular to fully bipolar profiles. A subset of higher-mass sources stand out as having almost no mainline emission and mostly double-peaked profiles. At least 25% of sources in the sample are variable at one or more of the frequencies observed. We also confirm a previously-noted 1667 MHz overshoot phenomenon.

  18. The ACT{sup 2} project: Demonstration of maximum energy efficiency in real buildings

    SciTech Connect (OSTI)

    Crawley, D.B. [Pacific Northwest Lab., Richland, WA (United States); Krieg, B.L. [Pacific Gas and Electric Co., San Ramon, CA (United States)

    1991-11-01T23:59:59.000Z

    A large US utility recently began a project to determine whether the use of new energy-efficient end-use technologies and systems would economically achieve substantial energy savings (perhaps as high as 75% over current practice). Using a field-based demonstration approach, the Advanced Customer Technology Test (ACT{sup 2}) for Maximum Energy Efficiency is providing information on the maximum energy savings possible when integrated packages of new high-efficiency end-use technologies are incorporated into commercial and residential buildings and industrial and agricultural processes. This paper details the underlying rationale, approach, results to date, and future plans for ACT{sup 2}. The ultimate goal is energy efficiency (doing more with less energy) rather than energy conservation (freezing in the dark). In this paper, we first explain why a major United States utility is committed to pursuing demand-side management so aggressively. Next, we discuss the approach the utility chose for conducting the ACT{sup 2} project. We then review results obtained to date from the project`s pilot demonstration site. Last, we describe other related demonstration projects being proposed by the utility.

  19. The ACT sup 2 project: Demonstration of maximum energy efficiency in real buildings

    SciTech Connect (OSTI)

    Crawley, D.B. (Pacific Northwest Lab., Richland, WA (United States)); Krieg, B.L. (Pacific Gas and Electric Co., San Ramon, CA (United States))

    1991-11-01T23:59:59.000Z

    A large US utility recently began a project to determine whether the use of new energy-efficient end-use technologies and systems would economically achieve substantial energy savings (perhaps as high as 75% over current practice). Using a field-based demonstration approach, the Advanced Customer Technology Test (ACT{sup 2}) for Maximum Energy Efficiency is providing information on the maximum energy savings possible when integrated packages of new high-efficiency end-use technologies are incorporated into commercial and residential buildings and industrial and agricultural processes. This paper details the underlying rationale, approach, results to date, and future plans for ACT{sup 2}. The ultimate goal is energy efficiency (doing more with less energy) rather than energy conservation (freezing in the dark). In this paper, we first explain why a major United States utility is committed to pursuing demand-side management so aggressively. Next, we discuss the approach the utility chose for conducting the ACT{sup 2} project. We then review results obtained to date from the project's pilot demonstration site. Last, we describe other related demonstration projects being proposed by the utility.

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

    SciTech Connect (OSTI)

    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

    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.

  1. Bounds and phase diagram of efficiency at maximum power for tight-coupling molecular motors

    E-Print Network [OSTI]

    Z. C. Tu

    2013-02-08T23:59:59.000Z

    The efficiency at maximum power (EMP) for tight-coupling molecular motors is investigated within the framework of irreversible thermodynamics. It is found that the EMP depends merely on the constitutive relation between the thermodynamic current and force. The motors are classified into four generic types (linear, superlinear, sublinear, and mixed types) according to the characteristics of the constitutive relation, and then the corresponding ranges of the EMP for these four types of molecular motors are obtained. The exact bounds of the EMP are derived and expressed as the explicit functions of the free energy released by the fuel in each motor step. A phase diagram is constructed which clearly shows how the region where the parameters (the load distribution factor and the free energy released by the fuel in each motor step) are located can determine whether the value of the EMP is larger or smaller than 1/2. This phase diagram reveals that motors using ATP as fuel under physiological conditions can work at maximum power with higher efficiency ($>1/2$) for a small load distribution factor ($<0.1$).

  2. Estimating the age of alleles by use of intraallelic variability

    SciTech Connect (OSTI)

    Slatkin, M.; Rannala, B. [Univ of California, Berkeley, CA (United States)

    1997-02-01T23:59:59.000Z

    A method is presented for estimating the age of an allele by use of its frequency and the extent of variation among different copies. The method uses the joint distribution of the number of copies in a population sample and the coalescence times of the intraallelic gene genealogy conditioned on the number of copies. The linear birth-death process is used to approximate the dynamics of a rare allele in a finite population. A maximum-likelihood estimate of the age of the allele is obtained by Monte Carlo integration over the coalescence times. The method is applied to two alleles at the cystic fibrosis (CFTR) locus, {Delta}F508 and G542X, for which intraallelic variability at three intronic microsatellite loci has been examined. Our results indicate that G542X is somewhat older than {Delta}F508. Although absolute estimates depend on the mutation rates at the microsatellite loci, our results support the hypothesis that {Delta}F508 arose <500 generations ({approx}10,000 years) ago. 32 refs., 4 figs.

  3. Cataclysmic variables in the SUPERBLINK proper motion survey

    SciTech Connect (OSTI)

    Skinner, Julie N.; Thorstensen, John R. [Department of Physics and Astronomy, 6127 Wilder Laboratory, Dartmouth College, Hanover, NH 03755-3528 (United States); Lépine, Sébastien, E-mail: jns@dartmouth.edu [Department of Physics and Astronomy, Georgia State University, 25 Park Place NE, Atlanta, GA 30303 (United States)

    2014-12-01T23:59:59.000Z

    We have discovered a new high proper motion cataclysmic variable (CV) in the SUPERBLINK proper motion survey, which is sensitive to stars with proper motions greater than 40 mas yr{sup ?1}. This CV was selected for follow-up observations as part of a larger search for CVs selected based on proper motions and their near-UV?V and V?K{sub s} colors. We present spectroscopic observations from the 2.4 m Hiltner Telescope at MDM Observatory. The new CV's orbital period is near 96 minutes, its spectrum shows the double-peaked Balmer emission lines characteristic of quiescent dwarf novae, and its V magnitude is near 18.2. Additionally, we present a full list of known CVs in the SUPERBLINK catalog.

  4. Multi-color Near Infra-red Intra-day and Short Term Variability of the Blazar S5 0716+714

    E-Print Network [OSTI]

    Alok C. Gupta; Sang-Mok Cha; Sungho Lee; Ho Jin; Soojong Pak; Seoung-hyun Cho; Bongkon Moon; Youngsik Park; In-Soo Yuk; Uk-won Nam; Jaemann Kyeong

    2008-09-19T23:59:59.000Z

    In this paper, we report results of our near-infrared (NIR) photometric variability studies of the BL Lacertae object S5 0716+714. NIR photometric observations spread over 7 nights during our observing run April 2-9, 2007 at 1.8 meter telescope equipped with KASINICS (Korea Astronomy and Space Science Institute Near Infrared Camera System) and J, H, and Ks filters at Bohyunsan Optical Astronomy Observatory (BOAO), South Korea. We searched for intra-day variability, short term variability and color variability in the BL Lac object. We have not detected any genuine intra-day variability in any of J, H, and Ks passbands in our observing run. Significant short term variability ~ 32.6%, 20.5% and 18.2% have been detected in J, H, Ks passbands, respectively, and ~ 11.9% in (J-H) color.

  5. THE RR LYRAE VARIABLES AND HORIZONTAL BRANCH OF NGC 6656 (M22) {sup ,}

    SciTech Connect (OSTI)

    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, Márcio [Pontificia Universidad Católica de Chile, Departamento de Astronomía y Astrofísica, Av. Vicuña 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

    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.

  6. Decreasing Cloudiness Over China: An Updated Analysis Examining Additional Variables

    SciTech Connect (OSTI)

    Kaiser, D.P.

    2000-01-14T23:59:59.000Z

    As preparation of the IPCC's Third Assessment Report takes place, one of the many observed climate variables of key interest is cloud amount. For several nations of the world, there exist records of surface-observed cloud amount dating back to the middle of the 20th Century or earlier, offering valuable information on variations and trends. Studies using such databases include Sun and Groisman (1999) and Kaiser and Razuvaev (1995) for the former Soviet Union, Angel1 et al. (1984) for the United States, Henderson-Sellers (1986) for Europe, Jones and Henderson-Sellers (1992) for Australia, and Kaiser (1998) for China. The findings of Kaiser (1998) differ from the other studies in that much of China appears to have experienced decreased cloudiness over recent decades (1954-1994), whereas the other land regions for the most part show evidence of increasing cloud cover. This paper expands on Kaiser (1998) by analyzing trends in additional meteorological variables for Chi na [station pressure (p), water vapor pressure (e), and relative humidity (rh)] and extending the total cloud amount (N) analysis an additional two years (through 1996).

  7. Remote sensing observations of ocean physical and biological properties in the region of the Southern Ocean Iron Experiment (SOFeX)

    E-Print Network [OSTI]

    Moore, J. Keith; Doney, Scott C

    2006-01-01T23:59:59.000Z

    Zone as observed from a mesoscale array of bio-opticalP. W. , et al. (2000), A mesoscale phytoplankton bloom infrontal dynamics and mesoscale variability in oligotrophic

  8. Assessing net ecosystem carbon exchange of U S terrestrial ecosystems by integrating eddy covariance flux measurements and satellite observations

    SciTech Connect (OSTI)

    Zhuang, Qianlai [Purdue University; Law, Beverly E. [Oregon State University; Baldocchi, Dennis [University of California, Berkeley; Ma, Siyan [University of California, Berkeley; Chen, Jiquan [University of Toledo, Toledo, OH; Richardson, Andrew [Harvard University; Melillo, Jerry [Marine Biological Laboratory; Davis, Ken J. [Pennsylvania State University; Hollinger, D. [USDA Forest Service; Wharton, Sonia [University of California, Davis; Falk, Matthias [University of California, Davis; Paw, U. Kyaw Tha [University of California, Davis; Oren, Ram [Duke University; Katulk, Gabriel G. [Duke University; Noormets, Asko [North Carolina State University; Fischer, Marc [Lawrence Berkeley National Laboratory (LBNL); Verma, Shashi [University of Nebraska; Suyker, A. E. [University of Nebraska, Lincoln; Cook, David R. [Argonne National Laboratory (ANL); Sun, G. [USDA Forest Service; McNulty, Steven G. [USDA Forest Service; Wofsy, Steve [Harvard University; Bolstad, Paul V [University of Minnesota; Burns, Sean [University of Colorado, Boulder; Monson, Russell K. [University of Colorado, Boulder; Curtis, Peter [Ohio State University, The, Columbus; Drake, Bert G. [Smithsonian Environmental Research Center, Edgewater, MD; Foster, David R. [Harvard University; Gu, Lianhong [ORNL; Hadley, Julian L. [Harvard University; Litvak, Marcy [University of New Mexico, Albuquerque; Martin, Timothy A. [University of Florida, Gainesville; Matamala, Roser [Argonne National Laboratory (ANL); Meyers, Tilden [NOAA, Oak Ridge, TN; Oechel, Walter C. [San Diego State University; Schmid, H. P. [Indiana University; Scott, Russell L. [USDA ARS; Torn, Margaret S. [Lawrence Berkeley National Laboratory (LBNL)

    2011-01-01T23:59:59.000Z

    More accurate projections of future carbon dioxide concentrations in the atmosphere and associated climate change depend on improved scientific understanding of the terrestrial carbon cycle. Despite the consensus that U.S. terrestrial ecosystems provide a carbon sink, the size, distribution, and interannual variability of this sink remain uncertain. Here we report a terrestrial carbon sink in the conterminous U.S. at 0.63 pg C yr 1 with the majority of the sink in regions dominated by evergreen and deciduous forests and savannas. This estimate is based on our continuous estimates of net ecosystem carbon exchange (NEE) with high spatial (1 km) and temporal (8-day) resolutions derived from NEE measurements from eddy covariance flux towers and wall-to-wall satellite observations from Moderate Resolution Imaging Spectroradiometer (MODIS). We find that the U.S. terrestrial ecosystems could offset a maximum of 40% of the fossil-fuel carbon emissions. Our results show that the U.S. terrestrial carbon sink varied between 0.51 and 0.70 pg C yr 1 over the period 2001 2006. The dominant sources of interannual variation of the carbon sink included extreme climate events and disturbances. Droughts in 2002 and 2006 reduced the U.S. carbon sink by 20% relative to a normal year. Disturbances including wildfires and hurricanes reduced carbon uptake or resulted in carbon release at regional scales. Our results provide an alternative, independent, and novel constraint to the U.S. terrestrial carbon sink.

  9. Cloud speed impact on solar variability scaling â?? Application to the wavelet variability model

    E-Print Network [OSTI]

    Lave, Matthew; Kleissl, Jan

    2013-01-01T23:59:59.000Z

    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

  10. Production-Intent Lost-Motion Variable Valve Actuation Systems...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Production-Intent Lost-Motion Variable Valve Actuation Systems Production-Intent Lost-Motion Variable Valve Actuation Systems Variable valve actuation with onoff IEGR pre-bump is...

  11. Interannual variability of Caribbean rainfall, ENSO and the Atlantic Ocean

    E-Print Network [OSTI]

    Columbia University

    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

  12. Variable speed operation of generators with rotor-speed feedback in wind power applications

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C.P.; Migliore, P.

    1995-11-01T23:59:59.000Z

    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.

  13. Variable speed operation of generators with rotor-speed feedback in wind power applications

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C.P.; Migliore, P. [National Renewable Energy Lab., Golden, CO (United States). Wind Technology Div.

    1996-10-01T23:59:59.000Z

    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.

  14. Variable speed operation of generators with rotor-speed feedback in wind power applications

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C.P.; Migliore, P. [National Renewable Energy Lab., Golden, CO (United States)

    1996-11-01T23:59:59.000Z

    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.

  15. Correlation between model observer and human observer performance in CT imaging when lesion location is uncertain

    SciTech Connect (OSTI)

    Leng, Shuai; Yu, Lifeng; Zhang, Yi; McCollough, Cynthia H. [Department of Radiology, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota 55905 (United States)] [Department of Radiology, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota 55905 (United States); Carter, Rickey [Department of Biostatistics, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota 55905 (United States)] [Department of Biostatistics, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota 55905 (United States); Toledano, Alicia Y. [Biostatistics Consulting, LLC, 10606 Wheatley Street, Kensington, Maryland 20895 (United States)] [Biostatistics Consulting, LLC, 10606 Wheatley Street, Kensington, Maryland 20895 (United States)

    2013-08-15T23:59:59.000Z

    Purpose: The purpose of this study was to investigate the correlation between model observer and human observer performance in CT imaging for the task of lesion detection and localization when the lesion location is uncertain.Methods: Two cylindrical rods (3-mm and 5-mm diameters) were placed in a 35 × 26 cm torso-shaped water phantom to simulate lesions with ?15 HU contrast at 120 kV. The phantom was scanned 100 times on a 128-slice CT scanner at each of four dose levels (CTDIvol = 5.7, 11.4, 17.1, and 22.8 mGy). Regions of interest (ROIs) around each lesion were extracted to generate images with signal-present, with each ROI containing 128 × 128 pixels. Corresponding ROIs of signal-absent images were generated from images without lesion mimicking rods. The location of the lesion (rod) in each ROI was randomly distributed by moving the ROIs around each lesion. Human observer studies were performed by having three trained observers identify the presence or absence of lesions, indicating the lesion location in each image and scoring confidence for the detection task on a 6-point scale. The same image data were analyzed using a channelized Hotelling model observer (CHO) with Gabor channels. Internal noise was added to the decision variables for the model observer study. Area under the curve (AUC) of ROC and localization ROC (LROC) curves were calculated using a nonparametric approach. The Spearman's rank order correlation between the average performance of the human observers and the model observer performance was calculated for the AUC of both ROC and LROC curves for both the 3- and 5-mm diameter lesions.Results: In both ROC and LROC analyses, AUC values for the model observer agreed well with the average values across the three human observers. The Spearman's rank order correlation values for both ROC and LROC analyses for both the 3- and 5-mm diameter lesions were all 1.0, indicating perfect rank ordering agreement of the figures of merit (AUC) between the average performance of the human observers and the model observer performance.Conclusions: In CT imaging of different sizes of low-contrast lesions (?15 HU), the performance of CHO with Gabor channels was highly correlated with human observer performance for the detection and localization tasks with uncertain lesion location in CT imaging at four clinically relevant dose levels. This suggests the ability of Gabor CHO model observers to meaningfully assess CT image quality for the purpose of optimizing scan protocols and radiation dose levels in detection and localization tasks for low-contrast lesions.

  16. KINKS AND DENTS IN PROTOPLANETARY DISKS: RAPID INFRARED VARIABILITY AS EVIDENCE FOR LARGE STRUCTURAL PERTURBATIONS

    SciTech Connect (OSTI)

    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

    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.

  17. Combustion Process in a Spark Ignition Engine: Analysis of Cyclic Maximum Pressure and Peak Pressure Angle

    E-Print Network [OSTI]

    G. Litak; T. Kaminski; J. Czarnigowski; A. K. Sen; M. Wendeker

    2006-11-29T23:59:59.000Z

    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.

  18. Role of ocean-atmosphere interactions in tropical cooling during the last glacial maximum

    SciTech Connect (OSTI)

    Bush, A.B.G. [Univ. of Alberta, Edmonton (Canada)] [Univ. of Alberta, Edmonton (Canada); Philander, S.G.H. [Princeton Univ., NJ (United States)] [Princeton Univ., NJ (United States)

    1998-02-27T23:59:59.000Z

    A simulation with a coupled atmosphere-ocean general circulation model configured for the Last Glacial Maximum delivered a tropical climate that is much cooler than that produced by atmosphere-only models. The main reason is a decrease in tropical sea surface temperatures, up to 6{degree}C in the western tropical Pacific, which occurs because of two processes. The trade winds induce equatorial upwelling and zonal advection of cold water that further intensify the trade winds, and an exchange of water occurs between the tropical and extratropical Pacific in which the poleward surface flow is balanced by equatorward flow of cold water in the thermocline. Simulated tropical temperature depressions are of the same magnitude as those that have been proposed from recent proxy data. 25 refs., 4 figs.

  19. Detailed analysis of an endoreversible fuel cell : Maximum power and optimal operating temperature determination

    E-Print Network [OSTI]

    A. Vaudrey; P. Baucour; F. Lanzetta; R. Glises

    2010-08-30T23:59:59.000Z

    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.

  20. Detailed analysis of an endoreversible fuel cell : Maximum power and optimal operating temperature determination

    E-Print Network [OSTI]

    Vaudrey, A; Lanzetta, F; Glises, R

    2009-01-01T23:59:59.000Z

    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.

  1. Bayesian and maximum entropy methods for fusion diagnostic measurements with compact neutron spectrometers

    SciTech Connect (OSTI)

    Reginatto, Marcel; Zimbal, Andreas [Physikalisch-Technische Bundesanstalt, 38116 Braunschweig (Germany)

    2008-02-15T23:59:59.000Z

    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.

  2. Maximum Achievable Control Technology for New Industrial Boilers (released in AEO2005)

    Reports and Publications (EIA)

    2005-01-01T23:59:59.000Z

    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.

  3. Azimuthal Anisotropy in Heavy Ion Collisions from the Maximum Entropy Method

    E-Print Network [OSTI]

    Pirner, Hans J

    2014-01-01T23:59:59.000Z

    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.

  4. Source Function Determined from HBT Correlations by the Maximum Entropy Principle

    E-Print Network [OSTI]

    Wu Yuanfang; Ulrich Heinz

    1996-07-18T23:59:59.000Z

    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.

  5. A maximum-entropy approach to the adiabatic freezing of a supercooled liquid

    E-Print Network [OSTI]

    Santi Prestipino

    2013-04-29T23:59:59.000Z

    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.

  6. Lyapunov exponent and natural invariant density determination of chaotic maps: An iterative maximum entropy ansatz

    E-Print Network [OSTI]

    Parthapratim Biswas; H. Shimoyama; L. R. Mead

    2009-10-23T23:59:59.000Z

    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.

  7. Spectral function and excited states in lattice QCD with maximum entropy method

    E-Print Network [OSTI]

    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. Yoshié

    2001-05-29T23:59:59.000Z

    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.

  8. Azimuthal Anisotropy in Heavy Ion Collisions from the Maximum Entropy Method

    E-Print Network [OSTI]

    Hans J. Pirner

    2014-05-09T23:59:59.000Z

    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.

  9. CP$^{N-1}$ model with the theta term and maximum entropy method

    E-Print Network [OSTI]

    Masahiro Imachi; Yasuhiko Shinno; Hiroshi Yoneyama

    2004-09-25T23:59:59.000Z

    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 ${\\cal Z}(\\theta)$.

  10. Observing alternatives to inflation

    E-Print Network [OSTI]

    P. Peter

    2009-12-07T23:59:59.000Z

    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.

  11. Is the friction angle the maximum slope of a free surface of a non cohesive material?

    E-Print Network [OSTI]

    A. Modaressi; P. Evesque

    2005-07-13T23:59:59.000Z

    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 .

  12. Thirty-Year Solid Waste Generation Maximum and Minimum Forecast for SRS

    SciTech Connect (OSTI)

    Thomas, L.C.

    1994-10-01T23:59:59.000Z

    This report is the third phase (Phase III) of the Thirty-Year Solid Waste Generation Forecast for Facilities at the Savannah River Site (SRS). Phase I of the forecast, Thirty-Year Solid Waste Generation Forecast for Facilities at SRS, forecasts the yearly quantities of low-level waste (LLW), hazardous waste, mixed waste, and transuranic (TRU) wastes generated over the next 30 years by operations, decontamination and decommissioning and environmental restoration (ER) activities at the Savannah River Site. The Phase II report, Thirty-Year Solid Waste Generation Forecast by Treatability Group (U), provides a 30-year forecast by waste treatability group for operations, decontamination and decommissioning, and ER activities. In addition, a 30-year forecast by waste stream has been provided for operations in Appendix A of the Phase II report. The solid wastes stored or generated at SRS must be treated and disposed of in accordance with federal, state, and local laws and regulations. To evaluate, select, and justify the use of promising treatment technologies and to evaluate the potential impact to the environment, the generic waste categories described in the Phase I report were divided into smaller classifications with similar physical, chemical, and radiological characteristics. These smaller classifications, defined within the Phase II report as treatability groups, can then be used in the Waste Management Environmental Impact Statement process to evaluate treatment options. The waste generation forecasts in the Phase II report includes existing waste inventories. Existing waste inventories, which include waste streams from continuing operations and stored wastes from discontinued operations, were not included in the Phase I report. Maximum and minimum forecasts serve as upper and lower boundaries for waste generation. This report provides the maximum and minimum forecast by waste treatability group for operation, decontamination and decommissioning, and ER activities.

  13. MADmap: A Massively Parallel Maximum-Likelihood Cosmic Microwave Background Map-Maker

    SciTech Connect (OSTI)

    Cantalupo, Christopher; Borrill, Julian; Jaffe, Andrew; Kisner, Theodore; Stompor, Radoslaw

    2009-06-09T23:59:59.000Z

    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.

  14. Kepler and the long-period variables

    SciTech Connect (OSTI)

    Hartig, Erich; Lebzelter, Thomas [University of Vienna, Department of Astrophysics, Türkenschanzstrasse 17, A-1180 Vienna (Austria); Cash, Jennifer [Department of Biological and Physical Sciences, South Carolina State University, P.O. Box 7024, Orangeburg, SC 29117 (United States); Hinkle, Kenneth H.; Mighell, Kenneth J. [National Optical Astronomy Observatories, P.O. Box 26732, Tucson, AZ 85726 (United States); Walter, Donald K., E-mail: erich.hartig@univie.ac.at, E-mail: thomas.lebzelter@univie.ac.at, E-mail: jcash@physics.scsu.edu, E-mail: hinkle@noao.edu, E-mail: mighell@noao.edu, E-mail: dkw@physics.scsu.edu [Department of Biological and Physical Sciences, South Carolina State University, P.O. Box 7296, Orangeburg, SC 29117 (United States)

    2014-12-01T23:59:59.000Z

    High-precision Kepler photometry is used to explore the details of asymptotic giant branch (AGB) light curves. Since AGB variability has a typical timescale on the order of a year, we discuss at length the removal of long-term trends and quarterly changes in Kepler data. Photometry for a small sample of nine semi-regular (SR) AGB stars is examined using a 30 minute cadence over a period of 45 months. While undergoing long-period variations of many magnitudes, the light curves are shown to be smooth at the millimagnitude level over much shorter time intervals. No flares or other rapid events were detected on a sub-day timescale. The shortest AGB period detected is on the order of 100 days. All the SR variables in our sample are shown to have multiple modes. This is always the first overtone, typically combined with the fundamental. A second common characteristic of SR variables is shown to be the simultaneous excitation of multiple closely separated periods for the same overtone mode. Approximately half the sample had a much longer variation in the light curve, likely a long secondary period (LSP). The light curves were all well represented by a combination of sinusoids. However, the properties of the sinusoids are time variable, with irregular variations present at low levels. No non-radial pulsations were detected. It is argued that the LSP variation seen in many SR variables is intrinsic to the star and linked to multiple mode pulsation.

  15. The Daytime Mixed Layer Observed by Radiosonde, Profiler, and LIDAR during MILAGRO

    SciTech Connect (OSTI)

    Shaw, William J.; Pekour, Mikhail S.; Coulter, Richard L.; Martin, Tim J.; Walters, Justin

    2007-10-19T23:59:59.000Z

    During the MILAGRO campaign centered in the Mexico City area, Pacific Northwest National Laboratory (PNNL) and Argonne National Laboratory (ANL) operated several atmospheric profiling systems at Veracruz and at two locations on the Central Mexican Plateau in the region around Mexico City. These systems included radiosondes, wind profilers, a sodar, and an aerosol backscatter lidar. An additional wind profiler was operated by the University of Alabama in Huntsville (UAH) at the Mexican Petroleum Institue (IMP) near the center of Mexico City. Because of the opportunity afforded by collocation of profilers, radiosondes, and a lidar, and because of the importance of boundary layer depth on aerosol properties, we have carried out a comparison of mixed layer depth as determined independently from these three types of measurement systems during the campaign. We have then used results of this comparison and additional measurements to develop a detailed description of the daily structure and evolution of the boundary layer on the Central Mexican Plateau during MILAGRO. Our analysis indicates that the profilers were more consistently successful in establishing the mixing layer depth during the daytime. The boundary layer growth was similar at the three locations, although the mixing layer tended to be slightly deeper in the afternoon in central Mexico City. The sodar showed that convection began about an hour after sunrise. Maximum daily mixed layer depths always reached 2000 m AGL and frequently extended to 4000 m. The rate and variability of mixing layer growth was essentially the same as that observed during the IMADA-AVER campaign in the same season in 1997. This growth did not seem to be related to whether deep convection was reported on a given day. Wind speeds within the boundary layer exhibited a daily low-altitude maximum in the late afternoon with lighter winds aloft, consistent with previous reports of diurnal regional circulations. Norte events, which produced high winds at Veracruz, did not appreciably modulate the winds on the plateau. Finally, despite the typically dry conditions at the surface, radiosonde profiles showed that relative humidity often exceeded 50% in the early morning and in the upper part of the boundary layer.

  16. Investigating Broadband Variability of the TeV Blazar 1ES 1959+650

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aliu, E.; Archambault, S.; Arlen, T.; Aune, T.; Barnacka, A.; Beilicke, M.; Benbow, W.; Berger, K.; Bird, R.; Bouvier, A.; et al

    2014-12-03T23:59:59.000Z

    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 thatmore »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.« less

  17. Investigating Broadband Variability of the TeV Blazar 1ES 1959+650

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    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

    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.

  18. Thermodynamic properties of mesoscale convective systems observed during BAMEX

    SciTech Connect (OSTI)

    Correia, James; Arritt, R.

    2008-11-01T23:59:59.000Z

    Dropsonde observations from the Bow-echo and Mesoscale convective vortex EXperiment (BAMEX) are used to document the spatio-temporal variability of temperature, moisture and wind within mesoscale convective systems (MCSs). Onion type sounding structures are found throughout the stratiform region of MCSs but the temperature and moisture variability is large. Composite soundings were constructed and statistics of thermodynamic variability were generated within each sub-region of the MCS. The calculated air vertical velocity helped identify subsaturated downdrafts. We found that lapse rates within the cold pool varied markedly throughout the MCS. Layered wet bulb potential temperature profiles seem to indicate that air within the lowest several km comes from a variety of source regions. We also found that lapse rate transitions across the 0 C level were more common than isothermal, melting layers. We discuss the implications these findings have and how they can be used to validate future high resolution numerical simulations of MCSs.

  19. MASe UCRL-15037 CONTINUOUSLY VARIABLE TRANSMISSIONS: THEORY AND...

    Office of Scientific and Technical Information (OSTI)

    transmission when operating in the power recirculation mode 20 Simple manual system to control the speed ratio of a variable V-belt continuously variable transmission 21 Schematic...

  20. Impact of subgrid-scale radiative heating variability on the...

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

    subgrid-scale radiative heating variability on the stratocumulus-to-trade cumulus transition in climate models. Impact of subgrid-scale radiative heating variability on the...