De-Xing Kong; Kefeng Liu; Ming Shen
2008-08-30
In this letter we construct a new time-periodic solution of the vacuum Einstein's field equations whose Riemann curvature norm takes the infinity at some points. We show that this solution is intrinsically time-periodic and describes a time-periodic universe with the "black hole". New physical phenomena are investigated and new singularities are analyzed for this universal model.
ANDERSON LOCALIZATION FOR TIME PERIODIC
disorder, Anderson localization in Z d is stable un- der localized time-periodic perturbations by proving random Schrodinger operators at large disorder has been well known since the seminal work of Fr is approximated by the potential V . The equation governing the system is (1.5) i @ @t = (#1; + V ) on Z d #2
Property:TimePeriod | Open Energy Information
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: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to:EA EIS Report Url JumpTechnology Jump to: navigation, search ThisTimePeriod
Emissions from Idling Trucks for Extended Time Periods | Department...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Idling Trucks for Extended Time Periods Emissions from Idling Trucks for Extended Time Periods 2002 DEER Conference Presentation: Oak Ridge National Laboratory 2002deerlewis.pdf...
Real-time Multi-period truckload routing problems
Limpaitoon, Tanachai
2008-01-01
In this thesis we consider a multi-period truckload pick-up and delivery problem dealing with real-time requests over a finite time horizon. We introduce the notion of postponement of requests, whereby the company can ...
Efficient Mining of Partial Periodic Patterns in Time Series Database
Dong, Guozhu
Efficient Mining of Partial Periodic Patterns in Time Series Database In ICDE 99 Jiawei Han \\Lambda peri odic patterns in timeseries databases, is an interesting data mining problem. Previous studies several algorithms for efficient mining of par tial periodic patterns, by exploring some interesting
Time-Periodic Solutions of the Einstein's Field Equations II
De-Xing Kong; Kefeng Liu; Ming Shen
2008-07-31
In this paper, we construct several kinds of new time-periodic solutions of the vacuum Einstein's field equations whose Riemann curvature tensors vanish, keep finite or take the infinity at some points in these space-times, respectively. The singularities of these new time-periodic solutions are investigated and some new physical phenomena are found. The applications of these solutions in modern cosmology and general relativity can be expected.
Particle energization through time-periodic helical magnetic fields
Mitra, Dhrubaditya; Dasgupta, Brahmananda; Niklasson, Eyvind; Ram, Abhay
2013-01-01
We solve for the motion of charged particles in a helical time-periodic ABC (Arnold-Beltrami-Childress) magnetic field. The magnetic field lines of a stationary ABC field with $A=B=C=1$ are chaotic, and we show that the motion of a charged particle in such a field is also chaotic at late time with positive Lyapunov exponent. We further show that in time-periodic (frequency $\\omega$) ABC fields the kinetic energy of a charged particle can increase indefinitely with time. At late times the mean kinetic energy grows as a power law in time with exponent $\\xi$ that approaches unity. For an initial distribution of particles, whose kinetic energy is uniformly distributed within some interval, the PDF of kinetic energy is, at late time, close to a Gaussian but with steeper tails.
Particle energization through time-periodic helical magnetic fields
Dhrubaditya Mitra; Axel Brandenburg; Brahmananda Dasgupta; Eyvind Niklasson; Abhay Ram
2014-04-30
We solve for the motion of charged particles in a helical time-periodic ABC (Arnold-Beltrami-Childress) magnetic field. The magnetic field lines of a stationary ABC field with coefficients $A=B=C=1$ are chaotic, and we show that the motion of a charged particle in such a field is also chaotic at late times with positive Lyapunov exponent. We further show that in time-periodic ABC fields, the kinetic energy of a charged particle can increase indefinitely with time. At late times the mean kinetic energy grows as a power law in time with an exponent that approaches unity. For an initial distribution of particles, whose kinetic energy is uniformly distributed within some interval, the PDF of kinetic energy is, at late times, close to a Gaussian but with steeper tails.
Particle energization through time-periodic helical magnetic fields
Mitra, Dhrubaditya
We solve for the motion of charged particles in a helical time-periodic ABC (Arnold-Beltrami-Childress) magnetic field. The magnetic field lines of a stationary ABC field with coefficients A=B=C=1 are chaotic, and we show ...
Local Lyapunov Functions for periodic and finite-time ODEs
Hafstein, Sigurður Freyr
Local Lyapunov Functions for periodic and finite-time ODEs Peter Giesl and Sigurdur Hafstein Abstract Lyapunov functions for general systems are difficult to construct. How- ever, for autonomous Lyapunov function by solving a matrix equa- tion. Consequently, the same function is a local Lyapunov
Time-periodic solutions of the Benjamin-Ono equation
Ambrose , D.M.; Wilkening, Jon
2008-04-01
We present a spectrally accurate numerical method for finding non-trivial time-periodic solutions of non-linear partial differential equations. The method is based on minimizing a functional (of the initial condition and the period) that is positive unless the solution is periodic, in which case it is zero. We solve an adjoint PDE to compute the gradient of this functional with respect to the initial condition. We include additional terms in the functional to specify the free parameters, which, in the case of the Benjamin-Ono equation, are the mean, a spatial phase, a temporal phase and the real part of one of the Fourier modes at t = 0. We use our method to study global paths of non-trivial time-periodic solutions connecting stationary and traveling waves of the Benjamin-Ono equation. As a starting guess for each path, we compute periodic solutions of the linearized problem by solving an infinite dimensional eigenvalue problem in closed form. We then use our numerical method to continue these solutions beyond the realm of linear theory until another traveling wave is reached (or until the solution blows up). By experimentation with data fitting, we identify the analytical form of the solutions on the path connecting the one-hump stationary solution to the two-hump traveling wave. We then derive exact formulas for these solutions by explicitly solving the system of ODE's governing the evolution of solitons using the ansatz suggested by the numerical simulations.
03.612 Time Off for Voting. 1. Purpose. To provide staff members a reasonable period of time off
03.612 Time Off for Voting. 1. Purpose. To provide staff members a reasonable period of time off a reasonable period of time off during the regular work day for voting on an official election day. This time should be reported as time worked and is not charged against vacation leave, comp time or salary
Does syntactic priming in children persist across significant time periods?
Hill, Louisa
2013-07-02
Using a ‘snap’ paradigm, we investigated the time course effects of syntactic priming in both adults and children. The research was done over a one week time frame in order to see whether priming is a long lived effect and ...
Time asymptotics of the Schroedinger wave function in time-periodic potentials
O. Costin; R. D. Costin; J. L. Lebowitz
2006-08-13
We study the transition to the continuum of an initially bound quantum particle in $\\RR^d$, $d=1,2,3$, subjected, for $t\\ge 0$, to a time periodic forcing of arbitrary magnitude. The analysis is carried out for compactly supported potentials, satisfying certain auxiliary conditions. It provides complete analytic information on the time Laplace transform of the wave function. From this, comprehensive time asymptotic properties (Borel summable transseries) follow. We obtain in particular a criterion for whether the wave function gets fully delocalized (complete ionization). This criterion shows that complete ionization is generic and provides a convenient test for particular cases. When satisfied it implies absence of discrete spectrum and resonances of the associated Floquet operator. As an illustration we show that the parametric harmonic perturbation of a potential chosen to be any nonzero multiple of the characteristic function of a measurable compact set has this property.
Efficient Solvers for Nonlinear Time-Periodic Eddy Current F. Bachinger
Schoeberl, Joachim
Efficient Solvers for Nonlinear Time-Periodic Eddy Current Problems F. Bachinger U. Langer J. Sch-periodic eddy current problems, ranging from the description of the nonlinearity to an efficient solution setup, the magnetic field and the thereby generated eddy currents hardly penetrate into conducting
QUANTUM ENERGY EXPECTATION IN PERIODIC TIME-DEPENDENT HAMILTONIANS VIA GREEN
1. Introduction Consider a general periodically driven quantum hamiltonian system H(t) = H0 + V (t the system then Um F is this state at time m. Typically, the unper- turbed hamiltonian H0 is assumed to have accelerator in which a particle can acquire unbounded energy from collisions with a heavy periodically moving
Local energy decay and Strichartz estimates for the wave equation with time-periodic
Petkov, Vesselin
Local energy decay and Strichartz estimates for the wave equation with time-periodic perturbations(z) = (U(T, 0) - z)-1 , (x) C 0 (Rn ), where U(t, s) is the propagator related to the wave equation) and T > 0 is the period. Assuming that R(z) has no poles z with |z| 1, we establish a local energy decay
Allen, Matthew S.
Identifying parameters of nonlinear structural dynamic systems using linear time- periodic nonlinearity. 1. Introduction Most dynamical systems behave nonlinearly in the most general scenario. This can point bifurcation [1], in rotor dynamic systems with bearing contact nonlinearities [2], in biomechanics
Real-time Scheduling of periodic tasks in a monoprocessor system with rechargeable energy storage
Paris-Sud XI, Université de
Real-time Scheduling of periodic tasks in a monoprocessor system with rechargeable energy storage-time computing system that is powered through a renewable energy storage device. In this context, two constraints for the properties of the energy source, capacity of the energy storage as well as energy consumption of the tasks
Quantum Energy Expectation in Periodic Time-Dependent hamiltonians via Green Functions
Cesar R. de Oliveira; Mariza S. Simsen
2009-07-31
Let $U_F$ be the Floquet operator of a time periodic hamiltonian $H(t)$. For each positive and discrete observable $A$ (which we call a {\\em probe energy}), we derive a formula for the Laplace time average of its expectation value up to time $T$ in terms of its eigenvalues and Green functions at the circle of radius $e^{1/T}$. Some simple applications are provided which support its usefulness.
Skolski, J. Z. P., E-mail: j.z.p.skolski@utwente.nl; Vincenc Obona, J. [Materials innovation institute M2i, Faculty of Engineering Technology, Chair of Applied Laser Technology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Römer, G. R. B. E.; Huis in 't Veld, A. J. [Faculty of Engineering Technology, Chair of Applied Laser Technology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands)
2014-03-14
A model predicting the formation of laser-induced periodic surface structures (LIPSSs) is presented. That is, the finite-difference time domain method is used to study the interaction of electromagnetic fields with rough surfaces. In this approach, the rough surface is modified by “ablation after each laser pulse,” according to the absorbed energy profile, in order to account for inter-pulse feedback mechanisms. LIPSSs with a periodicity significantly smaller than the laser wavelength are found to “grow” either parallel or orthogonal to the laser polarization. The change in orientation and periodicity follow from the model. LIPSSs with a periodicity larger than the wavelength of the laser radiation and complex superimposed LIPSS patterns are also predicted by the model.
Modeling the Coastal Ocean over a Time Period of Several April 8, 2008
Frénod, Emmanuel
, lost objects or oil spill over long periods of time in near coastal ocean areas. Such methods would. The final target of this program is to develop methods to forecast the drift of things like con- tainers be of interest for services in charge of maritime safety, environmental studies or pollution impact assessment
Periodicity detection and localization using spike timing from the AER EAR
Liu, Shih-Chii
Periodicity detection and localization using spike timing from the AER EAR Theodore Yu1 , Andrew Event Representation (AER) where each spike carries the identity of the sender. There are a handful of silicon cochleae with an Address Event type representation [4][5][6][7]. The AER EAR chip that we use
Risk neutral valuation of options in multi-period discrete-time markets
Risk neutral valuation of options in multi- period discrete-time markets In this lecture we study is the discounted expectation of its payoff under a martingale measure and use it to price call and put options Let F be an algebra of subsets of the finite sample space . Definition. A real-valued function (or
A Numerical Method for Computing Time-Periodic Solutions in Dissipative Wave Systems
Yang, Jianke
. Then this equation is computed in the combined spatiotemporal domain as a boundary value problem by Newton:420455 C 2015 Wiley Periodicals, Inc., A Wiley Company. #12;A Numerical Method for Computing Time gain or loss), these coherent structures generally exist as continuous families, parameterized
Classification of Floquet Statistical Distribution for Time-Periodic Open Systems
Dong E. Liu
2015-04-07
How to understand the order of Floquet stationary states in the presence of external bath coupling and their statistical mechanics is challenging; the answers are important for preparations and control of those Floquet states. Here, we propose a scheme to classify the statistical distribution of Floquet states for time-periodic systems which couple to an external heat bath. If an effective Hamiltonian and a system-bath coupling operator, which are all time-independent, can be simultaneously obtained via a time-periodic unitary transformation, the statistical mechanics of the Floquet states is equivalent to the equilibrium statistical mechanics of the effective Hamiltonian. In the large driving frequency cases, we also show that the conditions of this theorem can be weakened to: the time-period part in the system Hamiltonian commutes with the system-bath coupling operator. A Floquet-Markov approach is applied to numerically compute the Floquet state occupation distribution of a bosonic chain, and the results agree with the theoretical predictions.
Kafka, K R P; Li, H; Yi, A; Cheng, J; Chowdhury, E A
2015-01-01
Time-resolved diffraction microscopy technique has been used to observe the formation of laser-induced periodic surface structures (LIPSS) from the interaction of a single femtosecond laser pulse (pump) with a nano-scale groove mechanically formed on a single-crystal Cu substrate. The interaction dynamics (0-1200 ps) was captured by diffracting a time-delayed, frequency-doubled pulse from nascent LIPSS formation induced by the pump with an infinity-conjugate microscopy setup. The LIPSS ripples are observed to form sequentially outward from the groove edge, with the first one forming after 50 ps. A 1-D analytical model of electron heating and surface plasmon polariton (SPP) excitation induced by the interaction of incoming laser pulse with the groove edge qualitatively explains the time-evloution of LIPSS formation.
Time-Periodic Solutions of Driven-Damped Trimer Granular Crystals
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Charalampidis, E. G.; Li, F.; Chong, C.; Yang, J.; Kevrekidis, P. G.
2015-01-01
We consider time-periodic structures of granular crystals consisting of alternate chrome steel (S) and tungsten carbide (W) spherical particles where each unit cell follows the pattern of a 2?:?1 trimer: S-W-S. The configuration at the left boundary is driven by a harmonic in-time actuation with given amplitude and frequency while the right one is a fixed wall. Similar to the case of a dimer chain, the combination of dissipation, driving of the boundary, and intrinsic nonlinearity leads to complex dynamics. For fixed driving frequencies in each of the spectral gaps, we find that the nonlinear surface modes and the statesmore »dictated by the linear drive collide in a saddle-node bifurcation as the driving amplitude is increased, beyond which the dynamics of the system becomes chaotic. While the bifurcation structure is similar for solutions within the first and second gap, those in the first gap appear to be less robust. We also conduct a continuation in driving frequency, where it is apparent that the nonlinearity of the system results in a complex bifurcation diagram, involving an intricate set of loops of branches, especially within the spectral gap. The theoretical findings are qualitatively corroborated by the experimental full-field visualization of the time-periodic structures.« less
Internal Space-time Symmetries of Particles derivable from Periodic Systems in Optics
Y. S. Kim
2010-09-26
While modern optics is largely a physics of harmonic oscillators and two-by-two matrices, it is possible to learn about some hidden properties of the two-by-two matrix from optical systems. Since two-by-two matrices can be divided into three conjugate classes depending on their traces, optical systems force us to establish continuity from one class to another. It is noted that those three classes are equivalent to three different branches of Wigner's little groups dictating the internal space-time symmetries massive, massless, and imaginary-mass particles. It is shown that the periodic systems in optics can also be described by have the same class-based matrix algebra. The optical system allow us to make continuous, but not analytic, transitions from massiv to massless, and massless to imaginary-mass cases.
Zonal flow sawteeth and the time period between edge-localized transport bursts in tokamaks
Kleva, Robert G.; Guzdar, Parvez N.
2007-01-15
The time period between particle and energy transport bursts in simulations of tokamak edge turbulence is determined by the magnitude of the diamagnetic drift parameter {alpha}{sub d}{identical_to}{omega}{sub *}/{gamma}{sub 0}, where the diamagnetic drift frequency {omega}{sub *}={rho}{sub s}c{sub s}/L{sub 0}L{sub n} and the characteristic ballooning mode growth rate {gamma}{sub 0}=c{sub s}/(RL{sub n}/2){sup 1/2}. Here, R is the major radius of the torus, L{sub n} is the density gradient scale length, {rho}{sub s} is the ion gyroradius, and c{sub s} is the ion acoustic speed. The scale length L{sub 0} is given by L{sub 0}=2{pi}qR {nu}{sub ei}{rho}{sub s}/2{omega}{sub e}R){sup 1/2}(2R/L{sub n}){sup 1/4}, where q is the safety factor, {nu}{sub ei} is the electron-ion collision frequency, and {omega}{sub e} is the electron cyclotron frequency. When the diamagnetic drift frequency becomes larger than the ballooning mode growth rate ({alpha}{sub d}>1), then the transport in the tokamak edge is characterized by regularly recurring bursts of particles and energy with a single well-defined frequency. As {alpha}{sub d} increases above unity, the time period between the bursts becomes much longer. The temporal dependence of the energy in the zonal flow generated nonlinearly has the appearance of sawteeth.
A Time-Periodic Bifurcation Theorem and its Application to Navier-Stokes Flow Past an Obstacle
Giovanni P. Galdi
2015-08-04
We show an abstract time-periodic bifurcation theorem in Banach spaces. The key point as well as the novelty of the method is to split the original evolution equation into two different coupled equations, one for the time-average of the sought solution and the other for the "purely periodic" component. This approach may be particularly useful in studying physical phenomena occurring in unbounded spatial regions. Actually, we furnish a significant application of the theorem, by providing sufficient conditions for time-periodic bifurcation from a steady-state flow of a Navier-Stokes liquid past a three-dimensional obstacle.
Long time simulation of a beam in a periodic focusing channel via a two-scale PIC-method
Frénod, Emmanuel
Long time simulation of a beam in a periodic focusing channel via a two-scale PIC-method E. Fr. Keywords: Vlasov-Poisson system, kinetic equations, homogenization, two-scale convergence, two- scale PIC
Behavioral Self-Regulation and Relations to Academic Achievement across a Four Year Time Period
Cerda, Carissa Analise
2015-07-31
grades 1 to 4 predicts growth in academic achievement across that same time span. Longitudinal growth curve modeling (LGCM) was used to obtain growth trajectories for BSR, reading, and math across grades 1 to 4. Structural equation modeling (SEM) was used...
Reichenbach, Tobias
2015-01-01
Frequency discrimination is a fundamental task of the auditory system. The mammalian inner ear, or cochlea, provides a place code in which different frequencies are detected at different spatial locations. However, a temporal code based on spike timing is also available: action potentials evoked in an auditory-nerve fiber by a low-frequency tone occur at a preferred phase of the stimulus-they exhibit phase locking-and thus provide temporal information about the tone's frequency. In an accompanying psychoacoustic study, and in agreement with previous experiments, we show that humans employ this temporal information for discrimination of low frequencies. How might such temporal information be read out in the brain? Here we demonstrate that recurrent random neural networks in which connections between neurons introduce characteristic time delays, and in which neurons require temporally coinciding inputs for spike initiation, can perform sharp frequency discrimination when stimulated with phase-locked inputs. Alt...
John K. Cannizzo; Neil Gehrels; Janet A. Mattei
2002-07-11
We examine the AAVSO light curve of U Geminorum from 1908 to 2002, with particular focus on the October 1985 outburst. This outburst was longer than any other seen in U Gem by about a factor of 2, and appears to be unique among all dwarf nova outbursts seen in systems with orbital periods longer than 3 hr in that one can measure the decay time scale during the initial slow decay. This rate is ~26+-6 d/mag. Using estimates of the rate of accretion during outburst taken from Froning et al., one can show that ~1e24 g of gas was accreted onto the white dwarf during the outburst. When coupled with the viscous time inferred from the (short orbital period) SU UMa stars, the U Gem viscous time scale lends support to the standard model in which the decays in dwarf novae can either be viscous or thermal, with the ratio between them being roughly h/r where h is the vertical pressure scale height in the disk.
Rogers, J.; Porter, K.
2012-03-01
This paper updates previous work that describes time period-based and other approximation methods for estimating the capacity value of wind power and extends it to include solar power. The paper summarizes various methods presented in utility integrated resource plans, regional transmission organization methodologies, regional stakeholder initiatives, regulatory proceedings, and academic and industry studies. Time period-based approximation methods typically measure the contribution of a wind or solar plant at the time of system peak - sometimes over a period of months or the average of multiple years.
, an ID of the instrument installed is given above the line designating the period of installation 6. Profile tower CO2/H2O logger 7. Power system control logger 537 #12;Time Line Date 5/12/20015/12 . . Cell T volt divider . 0 .. . ... Main ... low er upper . . . Sw itched . S 762 ...... 83 . 470
Kriegel, Hans-Peter
, evolution of stock charts, research on medical behavior of organisms, or analysis and detec- tion of motion of environmental data. 1 Introduction In a large range of application domains, e.g. environmental analysis series. Overall, TiP serves as a framework to effectively and efficiently manage dual- domain time series
Jameson, Antony
of the body. Practical examples of this type include helicopter rotor blades in forward flight, rotor and efficient computation of periodic unsteady flows. The algorithm has been validated with both 2D and 3D test
Martinez, Tony R.
HONORS THESIS PLANNER Writing an Honors thesis is a significant undertaking. Ideally, a student will devote time over a twelve-to eighteen-month period to propose, research, and write the thesis. You may use this form to create your own thesis plan. Honors Program Deadlines December graduation April
Hinow, Peter
Summary Matrix tablets are drug delivery devices that release a water-soluble drug over an extended period of time. Such matrix tablets are formulated from mixtures of drug, polymer, and excipient powders variation in the drug release profile of the tablet. While fabrication of experimental tablets
Burleson, Kenneth Stewart
1958-01-01
of concrete are as foliose: Send (at a SSD condition) - - - - - 1266. 3 pounds Oearse (aC a SSD aen4ition) - - - - 166&. 1 pounds Oe?ent - - - - - - - - - - - - - - 607. 5 pounds or 6. &6 sachs gator - - - - - - - ? - - - - - - - 297. 0 pounds or 35. 66... and 185 F to obtain the waxima nodulus of rupture for a treataant period of 16 hours is indicated in Figures 29 through 32. *C ~ 1 day nodulus of rupture of concrete stean cured as show, expressed as a per cent of the 28 day nodulus of rupture...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Individual Permit Storm Water Analytical Period Storm Water Analytical Period The Individual Permit authorizes the discharge of storm water associated with historical industrial...
Periodic Measurement of Advertising Effectiveness Using Multiple-Test-Period Geo Experiments
Cortes, Corinna
of ad effectiveness measurements across time. Additionally, the experimental units should rotate betweenPeriodic Measurement of Advertising Effectiveness Using Multiple-Test-Period Geo Experiments Jon experiments to the measurement of advertising effectiveness. One reason this method of measurement
Periodic Reward-Based Scheduling and Its
Aydin, Hakan
catastrophic. Examples of real-time systems can be found in control systems of nuclear power plants, air36 Periodic Reward-Based Scheduling and Its Application to Power-Aware Real-Time Systems Hakan ........................... 36-9 Modeling Real-Time Workload and Energy on a Variable Speed CPU · Correlating Real-Time Power
Genealogy of periodic trajectories
de Adguiar, M.A.M.; Maldta, C.P.; de Passos, E.J.V.
1986-05-20
The periodic solutions of non-integrable classical Hamiltonian systems with two degrees of freedom are numerically investigated. Curves of periodic families are given in plots of energy vs. period. Results are presented for this Hamiltonian: H = 1/2(p/sub x//sup 2/ + p/sub y//sup 2/) + 1/2 x/sup 2/ + 3/2 y/sup 2/ - x/sup 2/y + 1/12 x/sup 4/. Properties of the families of curves are pointed out. (LEW)
Inference and Visualization of Periodic Sequences
Sun, Ying
2011-10-21
are evenly spaced in time. The period is estimated by a "leave-out-one-cycle" version of cross-validation (CV) and complements the periodogram, a widely used tool for period estimation. The CV method is computationally simple and implicitly penalizes...
Fourier series and periodicity
Donal F. Connon
2014-12-07
A large number of the classical texts dealing with Fourier series more or less state that the hypothesis of periodicity is required for pointwise convergence. In this paper, we highlight the fact that this condition is not necessary.
Broader source: Energy.gov [DOE]
DOE has published a Final Environmental Impact Statement (EIS), and the 30-day waiting period has ended. DOE is preparing a Record of Decision to announce and explain its chosen project alternative...
Ball Packings with Periodic Constraints
Robert Connelly; Jeffrey D. Shen; Alexander D. Smith
2013-01-04
We call a periodic ball packing in d-dimensional Euclidean space periodically (strictly) jammed with respect to a period lattice if there are no nontrivial motions of the balls that preserve the period (that maintain some period with smaller or equal volume). In particular, we call a packing consistently periodically (strictly) jammed if it is periodically (strictly) jammed on every one of its periods. After extending a well-known bar framework and stress condition to strict jamming, we prove that a packing with period Lambda is consistently strictly jammed if and only if it is strictly jammed with respect to Lambda and consistently periodically jammed. We next extend a result about rigid unit mode spectra in crystallography to characterize periodic jamming on sublattices. After that, we prove that there are finitely many strictly jammed packings of m unit balls and other similar results. An interesting example shows that the size of the first sublattice on which a packing is first periodically unjammed is not bounded. Finally, we find an example of a consistently periodically jammed packing of low density \\delta = \\frac{4 \\pi}{6 \\sqrt{3} + 11} + \\epsilon ~ 0.59, where \\epsilon is an arbitrarily small positive number. Throughout the paper, the statements for the closely related notions of periodic infinitesimal rigidity and affine infinitesimal rigidity for tensegrity frameworks are also given.
Quantum transport calculations using periodic boundaryconditions
Wang, Lin-Wang
2004-06-15
An efficient new method is presented to calculate the quantum transports using periodic boundary conditions. This method allows the use of conventional ground state ab initio programs without big changes. The computational effort is only a few times of a normal groundstate calculations, thus is makes accurate quantum transport calculations for large systems possible.
Kepler and the long-period variables
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)
2014-12-01
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.
The periodicity of the eta Carinae events
A. Damineli; M. F. Corcoran; D. J. Hillier; O. Stahl; R. S. Levenhagen; N. V. Leister; J. H. Groh; M. Teodoro; J. F. Albacete Colombo; F. Gonzalez; J. Arias; H. Levato; M. Grosso; N. Morrell; R. Gamen; G. Wallerstein; V. Niemela
2007-11-27
Extensive spectral observations of eta Carinae over the last cycle, and particularly around the 2003.5 low excitation event, have been obtained. The variability of both narrow and broad lines, when combined with data taken from two earlier cycles, reveal a common and well defined period. We have combined the cycle lengths derived from the many lines in the optical spectrum with those from broad-band X-rays, optical and near-infrared observations, and obtained a period length of 2022.7+-1.3 d. Spectroscopic data collected during the last 60 years yield an average period of 2020+-4 d, consistent with the present day period. The period cannot have changed by more than $\\Delta$P/P=0.0007 since 1948. This confirms the previous claims of a true, stable periodicity, and gives strong support to the binary scenario. We have used the disappearance of the narrow component of HeI 6678 to define the epoch of the Cycle 11 minimum, T_0=JD 2,452,819.8. The next event is predicted to occur on 2009 January 11 (+-2 days). The dates for the start of the minimum in other spectral features and broad-bands is very close to this date, and have well determined time delays from the HeI epoch.
Magnetomechanically induced long period fiber gratings
Causado-Buelvas, Jesus D.; Gomez-Cardona, Nelson D.; Torres, Pedro
2008-04-15
In this work, we report a simple, flexible method to create long period fiber gratings mechanically by controlling the repulsion/attraction force between two magnets that pressing a plate with a periodic array of small glass cylinders to a short length of optical fiber. Via the photoelastic effect, the pressure points induce the required periodic refractive index modulation to create the LPFG. We found that the induced device exhibits spectral characteristics similar to those of other types of LPFG. As the optical properties of LPFGs are directly related to the nature of the applied perturbations, we show, to our knowledge for the frrst time, how is the evolution of birefringence effects in mechanically induced LPFGs.
Classical Propagation of Light in Spatio-Temporal Periodic Media
Alexandrov, B S; Findikoglu, A T; Bishop, A R; Kostadinov, I Z
2006-01-01
We analyze the propagation of electromagnetic waves in media where the dielectric constants undergo rapid temporal periodic modulation. Both spatially homogeneous and periodic media are studied. Fast periodic temporal modulation of the dielectric constant of a homogeneous medium leads to existence of photonic band-gap like phenomena. In the presence of both spatial and tem- poral periodicity the electromagnetic spectrum is described in a four-dimensional cube, defining an effective Brillouin zone. In the case of incommensurability between space and time periodicities, completely dispersed point spectra exist.
Time period Annual mean [DOC] 95% CI (mg l-1)
can we measure the impacts on peatland? Streamwater can be sampled upstream and downstream downstream of forest felling were mostly higher than the sampling points upstream. The mean concentrations the results show? There has been a slight increase in [DOC] downstream of forest felling, tracks, turbine
Time-periodic solutions of the Benjamin-Ono equation
Ambrose, D.M.
2009-01-01
application to Benjamin Ono equation. Chinese Physics, 14(solutions of Hamiltonian equations. In Dynamics and Pro-quelques generalisations de l’equation de Korteweg-deVries.
Representing Periodic Functions by Fourier
Vickers, James
Representing Periodic Functions by Fourier Series 23.2 Introduction In this Section we show how, then the Fourier series expansion takes the form: f(t) = a0 2 + n=1 (an cos nt + bn sin nt) Our main purpose here Fourier coefficients of a function of period 2 calculate Fourier coefficients of a function of general
Shortest recurrence periods of novae
Kato, Mariko [Department of Astronomy, Keio University, Hiyoshi, Yokohama 223-8521 (Japan); Saio, Hideyuki [Astronomical Institute, Graduate School of Science, Tohoku University, Sendai 980-8578 (Japan); Hachisu, Izumi [Department of Earth Science and Astronomy, College of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902 (Japan); Nomoto, Ken'ichi, E-mail: mariko@educ.cc.keio.ac.jp [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan)
2014-10-01
Stimulated by the recent discovery of the 1 yr recurrence period nova M31N 2008-12a, we examined the shortest recurrence periods of hydrogen shell flashes on mass-accreting white dwarfs (WDs). We discuss the mechanism that yields a finite minimum recurrence period for a given WD mass. Calculating the unstable flashes for various WD masses and mass accretion rates, we identified a shortest recurrence period of about two months for a non-rotating 1.38 M {sub ?} WD with a mass accretion rate of 3.6 × 10{sup –7} M {sub ?} yr{sup –1}. A 1 yr recurrence period is realized for very massive (? 1.3 M {sub ?}) WDs with very high accretion rates (? 1.5 × 10{sup –7} M {sub ?} yr{sup –1}). We revised our stability limit of hydrogen shell burning, which will be useful for binary evolution calculations toward Type Ia supernovae.
Competitive Multi-period Pricing with Fixed Inventories
Perakis, Georgia
This paper studies the problem of multi-period pricing for perishable products in a competitive (oligopolistic) market. We study non cooperative Nash equilibrium policies for sellers. At the beginning of the time horizon, ...
Analytic aspects of periodic instantons
Charbonneau, Benoit, 1976-
2004-01-01
The main result is a computation of the Nahm transform of a SU(2)-instanton over R x T³, called spatially-periodic instanton. It is a singular monopole over T³, a solution to the Bogomolny equation, whose rank is computed ...
Stratified Steady Periodic Water Waves
Samuel Walsh
2009-02-11
This paper considers two-dimensional stratified water waves propagating under the force of gravity over an impermeable flat bed and with a free surface. We prove the existence of a global continuum of classical solutions that are periodic and traveling. These waves, moreover, can exhibit large density variation, speed and amplitude.
Advanced downhole periodic seismic generator
Hardee, Harry C. (Albuquerque, NM); Hills, Richard G. (Las Cruces, NM); Striker, Richard P. (Albuquerque, NM)
1991-07-16
An advanced downhole periodic seismic generator system for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.
Down hole periodic seismic generator
Hardee, Harry C. (Albuquerque, NM); Hills, Richard G. (Las Cruces, NM); Striker, Richard P. (Albuquerque, NM)
1989-01-01
A down hole periodic seismic generator system for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.
An Autonomous Adaptive Scheduling Agent for Period Searching
Eric S. Saunders; Tim Naylor; Alasdair Allan
2008-01-24
We describe the design and implementation of an autonomous adaptive software agent that addresses the practical problem of observing undersampled, periodic, time-varying phenomena using a network of HTN-compliant robotic telescopes. The algorithm governing the behaviour of the agent uses an optimal geometric sampling technique to cover the period range of interest, but additionally implements proactive behaviour that maximises the optimality of the dataset in the face of an uncertain and changing operating environment.
Long period fiber gratings induced by mechanical resonance
Shahal, Shir; Duadi, Hamootal; Fridman, Moti
2015-01-01
We present a simple, and robust method for writing long period fiber gratings with low polarization dependent losses. Our method is based on utilizing mechanical vibrations of the tapered fiber while pooling it. Our method enables real-time tunability of the periodicity, efficiency and length of the grating. We also demonstrate complex grating by writing multiple gratings simultaneously. Finally, we utilized the formation of the gratings in different fiber diameters to investigate the Young's modulus of the fiber.
Evolution of the periodicities in 2S 0114+650
Ravi Sood; Sean Farrell; Paul O'Neill; Ravi Manchanda; N. M. Ashok
2006-03-01
We have analysed nine years of data from the All Sky Monitor on the Rossi X-ray Timing Explorer for 2S 0114+650 to study the evolution of its spin, binary and super-orbital periods. The spin history of the neutron star in this system exhibits torque reversals lasting ~1 yr. The newly discovered super-orbital period has remained stable over the 9-yr span, making 2S 0114+650 the fourth known system to exhibit stable super-orbital modulation. We compare its super-orbital period evolution with those of the other three such systems.
Frozen light in periodic metamaterials
A. Figotin; I. Vitebskiy
2006-09-16
Wave propagation in spatially periodic media, such as photonic crystals, can be qualitatively different from any uniform substance. The differences are particularly pronounced when the electromagnetic wavelength is comparable to the primitive translation of the periodic structure. In such a case, the periodic medium cannot be assigned any meaningful refractive index. Still, such features as negative refraction and/or opposite phase and group velocities for certain directions of light propagation can be found in almost any photonic crystal. The only reservation is that unlike hypothetical uniform left-handed media, photonic crystals are essentially anisotropic at frequency range of interest. Consider now a plane wave incident on a semi-infinite photonic crystal. One can assume, for instance, that in the case of positive refraction, the normal components of the group and the phase velocities of the transmitted Bloch wave have the same sign, while in the case of negative refraction, those components have opposite signs. What happens if the normal component of the transmitted wave group velocity vanishes? Let us call it a "zero-refraction" case. At first sight, zero normal component of the transmitted wave group velocity implies total reflection of the incident wave. But we demonstrate that total reflection is not the only possibility. Instead, the transmitted wave can appear in the form of an abnormal grazing mode with huge amplitude and nearly tangential group velocity. This spectacular phenomenon is extremely sensitive to the frequency and direction of propagation of the incident plane wave. These features can be very attractive in numerous applications, such as higher harmonic generation and wave mixing, light amplification and lasing, highly efficient superprizms, etc.
Dynamical system theory of periodically collapsing bubbles
Yukalov, V I; Sornette, D
2015-01-01
We propose a reduced form set of two coupled continuous time equations linking the price of a representative asset and the price of a bond, the later quantifying the cost of borrowing. The feedbacks between asset prices and bonds are mediated by the dependence of their "fundamental values" on past asset prices and bond themselves. The obtained nonlinear self-referencing price dynamics can induce, in a completely objective deterministic way, the appearance of periodically exploding bubbles ending in crashes. Technically, the periodically explosive bubbles arise due to the proximity of two types of bifurcations as a function of the two key control parameters $b$ and $g$, which represent, respectively, the sensitivity of the fundamental asset price on past asset and bond prices and of the fundamental bond price on past asset prices. One is a Hopf bifurcation, when a stable focus transforms into an unstable focus and a limit cycle appears. The other is a rather unusual bifurcation, when a stable node and a saddle...
Quasi-periodic oscillations of perturbed tori
Parthasarathy, Varadarajan; Kluzniak, Wlodek
2015-01-01
We performed axisymmetric hydrodynamic simulations of perturbed tori orbiting a black hole. The tori in equilibrium were constructed with a constant distribution of angular momentum in a pseudo-Newtonian potential (Klu{\\'z}niak-Lee). Epicyclic motions were triggered by adding sub-sonic velocity fields: radial, vertical and diagonal to the tori in equilibrium. As the perturbed tori evolved in time, we measured $L_{2}$ norm of density and obtained the power spectrum of $L_{2}$ norm which manifested eigenfrequencies of tori modes. We observe a pair of modes which occur in an approximate 3:2 ratio. Results from our simulations are relevant in the context of high-frequency quasi-periodic oscillations (HF QPOs) observed in stellar-mass black hole binaries.
Planar resonant periodic orbits in Kuiper belt dynamics
George Voyatzis; Thomas Kotoulas
2005-02-28
In the framework of the planar restricted three body problem we study a considerable number of resonances associated to the Kuiper Belt dynamics and located between 30 and 48 a.u. Our study is based on the computation of resonant periodic orbits and their stability. Stable periodic orbits are surrounded by regular librations in phase space and in such domains the capture of trans-Neptunian object is possible. All the periodic orbits found are symmetric and there is evidence for the existence of asymmetric ones only in few cases. In the present work first, second and third order resonances are under consideration. In the planar circular case we found that most of the periodic orbits are stable. The families of periodic orbits are temporarily interrupted by collisions but they continue up to relatively large values of the Jacobi constant and highly eccentric regular motion exists for all cases. In the elliptic problem and for a particular eccentricity value of the primary bodies the periodic orbits are isolated. The corresponding families, where they belong to, bifurcate from specific periodic orbits of the circular problem and seem to continue up to the rectilinear problem. Both stable and unstable orbits are obtained for each case. In the elliptic problem the unstable orbits found are associated with narrow chaotic domains in phase space. The evolution of the orbits, which are located in such chaotic domains, seems to be practically regular and bounded for long time intervals.
Periodic relativity: basic framework of the theory
Vikram H. Zaveri
2014-11-25
An alternative gravity theory is proposed which does not rely on Riemannian geometry and geodesic trajectories. The theory named periodic relativity (PR) does not use the weak field approximation and allows every two body system to deviate differently from the flat Minkowski metric. PR differs from general relativity (GR) in predictions of the proper time intervals of distant objects. PR proposes a definite connection between the proper time interval of an object and gravitational frequency shift of its constituent particles as the object travels through the gravitational field. PR is based on the dynamic weak equivalence principle which equates the gravitational mass with the relativistic mass. PR provides very accurate solutions for the Pioneer anomaly and the rotation curves of galaxies outside the framework of general relativity. PR satisfies Einstein's field equations with respect to the three major GR tests within the solar system and with respect to the derivation of Friedmann equation in cosmology. This article defines the underlying framework of the theory.
Passive Tracer Dispersion with Random or Periodic Source \\Lambda
Passive Tracer Dispersion with Random or Periodic Source \\Lambda Jinqiao Duan Clemson University sources on the pattern formation and longÂtime behavior of concentration proÂ files of passive tracers Introduction The dispersion of passive tracers (or passive scalars) occur in various geoÂ physical
Passive Tracer Dispersion with Random or Periodic Source
Passive Tracer Dispersion with Random or Periodic Source Jinqiao Duan Clemson University sources on the pattern formation and long-time behavior of concentration pro- #12;les of passive tracers #12;1 Introduction The dispersion of passive tracers (or passive scalars) occur in various geo
The Chinese Calendar of The Later Han Period
Aslaksen, Helmer
The Chinese Calendar of The Later Han Period Undergraduate Research Opportunities Programme would like to learn some basic knowledge in the Chinese calendar, which is an important part of the Chinese culture and Chinese history. However, by the time we decided to take this project, the deadline
Numerical Modeling of Periodic Composite Media for Electromagnetic Shielding Application
Koledintseva, Marina Y.
on a conventional mixing theory, have served as the fundamentals for these techniques. In these formulationsNumerical Modeling of Periodic Composite Media for Electromagnetic Shielding Application Dagang Wu-difference time-domain (FDTD) method. The results are compared with conventional mixing theories and 3D Fourier
Oscillations with uniquely long periods in a microfluidic bubble generator
Loss, Daniel
LETTERS Oscillations with uniquely long periods in a microfluidic bubble generator PIOTR GARSTECKI1 generator that shows stable oscillatory patterns (both in space and time) of unanticipated complexity to a single outlet channel. In this geometry, the pinch-off process that generates bubbles is regulated17
Long-period pulses Motivation Developed program Results Long-period disturbances in records of Swiss
Cerveny, Vlastislav
Long-period pulses Motivation Developed program Results Long-period disturbances in records 2014 #12;Long-period pulses Motivation Developed program Results Index 1 Long-period pulses in records 2 Motivation for the study 3 Developed program 4 Results #12;Long-period pulses Motivation Developed
A Periodic Solution to Impulsive Logistic Equation
Gyong-Chol Kim; Hyong-Chol O; Sang-Mun Kim; Chol Kim
2014-03-28
In this paper is provided a new representation of periodic solution to the impulsive Logistic equation considered in [7].
Periods Associated to Algebraic Cycles Spencer Bloch
Bloch, Spencer
K0(X) = CHp (X)Q Spencer Bloch () Periods Associated to Algebraic Cycles March 3, 2014 Albert) CHp(X, n) := H-n(Zp(X, ·)). Spencer Bloch () Periods Associated to Algebraic Cycles March 3, 2014 ) - Zp (X) CHp(X, n) := H-n(Zp(X, ·)). Spencer Bloch () Periods Associated to Algebraic Cycles March 3
Detection of superimposed periodic signals using wavelets
X. Otazu; M. Ribo; M. Peracaula; J. M. Paredes; J. Nunez
2002-02-05
In this paper we present a wavelet based algorithm that is able to detect superimposed periodic signals in data with low signal-noise ratio. In this context, the results given by classical period determination methods highly depend on the intrinsic characteristics of each periodic signal, like amplitude or profile. It is then difficult to detect the different periods present in the data set. The results given by the wavelet based method for period determination we present here are independent of the characteristics of the signals.
Seismic isolation of two dimensional periodic foundations
Yan, Y.; Mo, Y. L.; Laskar, A.; Cheng, Z.; Shi, Z.; Menq, F.; Tang, Y.
2014-07-28
Phononic crystal is now used to control acoustic waves. When the crystal goes to a larger scale, it is called periodic structure. The band gaps of the periodic structure can be reduced to range from 0.5?Hz to 50?Hz. Therefore, the periodic structure has potential applications in seismic wave reflection. In civil engineering, the periodic structure can be served as the foundation of upper structure. This type of foundation consisting of periodic structure is called periodic foundation. When the frequency of seismic waves falls into the band gaps of the periodic foundation, the seismic wave can be blocked. Field experiments of a scaled two dimensional (2D) periodic foundation with an upper structure were conducted to verify the band gap effects. Test results showed the 2D periodic foundation can effectively reduce the response of the upper structure for excitations with frequencies within the frequency band gaps. When the experimental and the finite element analysis results are compared, they agree well with each other, indicating that 2D periodic foundation is a feasible way of reducing seismic vibrations.
Do triatomic molecules echo atomic periodicity?
Hefferlin, R. Barrow, J.
2015-03-30
Demonstrations of periodicity among triatomic-molecular spectroscopic constants underscore the role of the periodic law as a foundation of chemistry. The objective of this work is to prepare for another test using vibration frequencies ?{sub 1} of free, ground-state, main-group triatomic molecules. Using data from four data bases and from computation, we have collected ?{sub 1} data for molecules formed from second period atoms.
Pricing Conspicuous Consumption Products in Recession Periods ...
2012-09-26
cally used in chemical engineering, e.g., to avoid irreversible reactions in ... Our basic problem is based on an economic setting with a recession period followed.
Time Limitation on Direct Subsidized Loan Eligibility for First-Time Borrowers on or after
Fernandez, Eduardo
Time Limitation on Direct Subsidized Loan Eligibility for First-Time Borrowers on or after July 1, 2013 Maximum eligibility period to receive Direct Subsidized Loans There is a limit on the maximum period of time (measured in academic years) that you can receive Direct Subsidized Loans. In general, you
Periodic cellular automata and Bethe ansatz
Atsuo Kuniba; Akira Takenouchi
2006-01-07
We review and generalize the recent progress in a soliton cellular automaton known as the periodic box-ball system. It has the extended affine Weyl group symmetry and admits the commuting transfer matrix method and the Bethe ansatz at q=0. Explicit formulas are proposed for the dynamical period and the number of states characterized by conserved quantities.
SYMBOLS FOR TIME = time variable
Duchowski, Andrew T.
=forever) Cost spent to build variation point i at time i = index over variation points #12;SYMBOLS FOR TIME to account for net present value of money r = assumed interest rate i = index over variation points Cost Expected cost summed over all relevant time intervals Cost spent to build variation point i at time r
Variable-Period Undulators For Synchrotron Radiation
Shenoy, Gopal (Naperville, IL); Lewellen, John (Plainfield, IL); Shu, Deming (Darien, IL); Vinokurov, Nikolai (Novosibirsk, RU)
2005-02-22
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.
Traveling Waves Solutions for Bistable Differential-Difference Equations with Periodic Diffusion
Elmer, Christopher E.; Van Vleck, Erik
2001-10-05
on the underlying lattice as well as on time. For the case of spatially periodic diffusion we obtain analytic solutions for the traveling wave problem using a piecewise linear nonlinearity. The formula for the wave forms is implicitly defined in the general periodic...
Temporal evolution of long-timescale periodicities in ULX NGC 5408 X-1
An, Tao; Wang, Jun-Yi
2015-01-01
Context. NGC 5408 X-1 is one of the few ultraluminous X-ray sources with an extensive monitoring program in X-rays (a temporal baseline of 4.2 yr), making it one of the most suitable candidates to study the long-timescale quasi-periodic oscillations (QPOs). Aims. Previous timing analysis of the Swift data of NGC 5408 X-1 led to detection of multiple periodicities ranging from 2.6 d to 230 d. In this paper, we focus on the statistical significance and the temporal evolution of these periodicities. Methods. A time-series analysis technique in the time-frequency domain, the weighted wavelet Z-transform (WWZ), was employed to identify the periodicities and trace their variations with time. Results. Three periodic components were detected from the WWZ periodogram, corresponding to periods of 2.65$\\pm$0.01 d, 115.4$\\pm$14.4 d and 189.1$\\pm$15.2 d. All three have statistical significance higher than 99.74%. The 2.65-d periodicity is quite stable in the majority of the light curve. The 115-d periodicity is the most p...
Burra G. Sidharth
2008-09-03
We briefly review two concepts of time - the usual time associated with "being" and more recent ideas, answering to the description of "becoming". The approximation involved in the former is examined. Finally we argue that it is (unpredictable) fluctuations that underlie time.
Dynamics of Periodically-kicked Oscillators
Kevin K. Lin; Lai-Sang Young
2010-04-21
We review some recent results surrounding a general mechanism for producing chaotic behavior in periodically-kicked oscillators. The key geometric ideas are illustrated via a simple linear shear model.
Impact of Motor Failures on Payback Periods
Cheek, K. F.; Pillay, P.; Dudley, K. J.
1995-01-01
This paper uses MotorMaster and Vaughen's Complete Price Guide to determine payback periods for different motor failure scenarios. Some scenarios considered are rewinds, reconditions, and replacement of bearings. Prices for these repairs...
University of Oregon Libraries Types of Periodicals
Lockery, Shawn
University of Oregon Libraries Types of Periodicals Scholarly Sources Popular Sources SCHOLARLY American Quarterly RN Automotive News Library Journal Restaurants & Institutions Chemical Engineering News & biographical information Statistics, including forecasts Some book reviews Commentary on political & social
QM/MM description of periodic systems
Doll, K
2015-01-01
A QM/MM implementation for periodic systems is reported. This is done for the case of molecules and for systems with two and three-dimensional periodicity, which is suitable to model electrolytes in contact with electrodes. Tests on different water-containing systems, ranging from the water dimer up to liquid water indicate the correctness of the scheme. Furthermore, molecular dynamics simulations are performed, as a possible direction to study realistic systems.
Quasi-bound states in periodically driven scattering
H. Landa
2015-06-29
We present an approach for obtaining eigenfunctions of periodically driven time-dependent Hamiltonians. Assuming an approximate scale separation between two spatial regions where different potentials dominate, we derive an explicit expansion for scattering problems with mixed cylindrical and spherical symmetry, by matching wavefunctions of a periodic linear drive in the exterior region to solutions of an arbitrary interior potential expanded in spherical waves. Using this method we study quasi-bound states of a square-well potential in three dimensions subject to an axial driving force. In the nonperturbative regime we show how eigenfunctions develop an asymptotic dressing of different partial waves, accompanied by large periodic oscillations in the angular momentum and a nonmonotonous dependence of the decay rate on the drive strength. We extend these results to the strong driving regime near a resonant intersection of the quasi-energy surfaces of two bound states of different symmetry. Our approach can be applied to general quantum scattering problems of particles subject to periodic fields.
John Ashmead
2010-05-05
Normally we quantize along the space dimensions but treat time classically. But from relativity we expect a high level of symmetry between time and space. What happens if we quantize time using the same rules we use to quantize space? To do this, we generalize the paths in the Feynman path integral to include paths that vary in time as well as in space. We use Morlet wavelet decomposition to ensure convergence and normalization of the path integrals. We derive the Schr\\"odinger equation in four dimensions from the short time limit of the path integral expression. We verify that we recover standard quantum theory in the non-relativistic, semi-classical, and long time limits. Quantum time is an experiment factory: most foundational experiments in quantum mechanics can be modified in a way that makes them tests of quantum time. We look at single and double slits in time, scattering by time-varying electric and magnetic fields, and the Aharonov-Bohm effect in time.
Periodic subsystem density-functional theory
Genova, Alessandro; Pavanello, Michele; Ceresoli, Davide
2014-11-07
By partitioning the electron density into subsystem contributions, the Frozen Density Embedding (FDE) formulation of subsystem Density Functional Theory (DFT) has recently emerged as a powerful tool for reducing the computational scaling of Kohn–Sham DFT. To date, however, FDE has been employed to molecular systems only. Periodic systems, such as metals, semiconductors, and other crystalline solids have been outside the applicability of FDE, mostly because of the lack of a periodic FDE implementation. To fill this gap, in this work we aim at extending FDE to treat subsystems of molecular and periodic character. This goal is achieved by a dual approach. On one side, the development of a theoretical framework for periodic subsystem DFT. On the other, the realization of the method into a parallel computer code. We find that periodic FDE is capable of reproducing total electron densities and (to a lesser extent) also interaction energies of molecular systems weakly interacting with metallic surfaces. In the pilot calculations considered, we find that FDE fails in those cases where there is appreciable density overlap between the subsystems. Conversely, we find FDE to be in semiquantitative agreement with Kohn–Sham DFT when the inter-subsystem density overlap is low. We also conclude that to make FDE a suitable method for describing molecular adsorption at surfaces, kinetic energy density functionals that go beyond the GGA level must be employed.
Abreu, Gabriel
2010-01-01
In a general time-dependent (3+1)-dimensional spherically symmetric spacetime, the so-called Kodama vector is a naturally defined geometric quantity that is timelike outside the evolving horizon and so defines a preferred class of fiducial observers. However the Kodama vector does not by itself define any preferred notion of time. We demonstrate that a preferred time coordinate - which we shall call Kodama time - can be introduced by taking the additional step of applying the Clebsch decomposition theorem to the Kodama vector. We thus construct a geometrically preferred coordinate system for any time-dependent spherically symmetric spacetime, and explore its properties. In particular we use this formalism to construct a general class of conservation laws, generalizing Kodama's energy flux. We study the geometrically preferred fiducial observers, and demonstrate that it is possible to define and calculate a generalized notion of surface gravity that is valid throughout the entire evolving spacetime. Furthermor...
Sequential conditions for fixed and periodic points
Peters, Burnis Charles
1970-01-01
) (Member) ~A (Month) 1970 (Year) ~04SQQ ABSTRACT Sec, uential Conditions fo. Fixed and Periodic Points (August 1970) Burnis C. Peter, Jr. , B. A. , Texas ASM University; M. S. , Texas A&M University Directed by: Jack Bryant and L. F. Guseman, Jr.... Let (X, d) be a metric space and f a selfmap of X. It is shown that a number of known theorems on the existence of fixed and periodic points are related through simple properties of the n sequence (f ) of iterates . ACMOVI. EDGEMENTS I wish...
Emergent hyperuniformity in periodically-driven emulsions
Joost H. Weijs; Raphaël Jeanneret; Rémi Dreyfus; Denis Bartolo
2015-04-28
We report the emergence of large-scale hyperuniformity in microfluidic emulsions. Upon periodic driving confined emulsions undergo a first-order transition from a reversible to an irreversible dynamics. We evidence that this dynamical transition is accompanied by structural changes at all scales yielding macroscopic yet finite hyperuniform structures. Numerical simulations are performed to single out the very ingredients responsible for the suppression of density fluctuations. We show that as opposed to equilibrium systems the long-range nature of the hydrodynamic interactions are not required for the formation of hyperuniform patterns, thereby suggesting a robust relation between reversibility and hyperuniformity which should hold in a broad class of periodically driven materials.
PULSATION PERIOD VARIATIONS IN THE RRc LYRAE STAR KIC 5520878
Hippke, Michael; Learned, John G.; Zee, A.; Edmondson, William H.; Lindner, John F.; Kia, Behnam; Ditto, William L.; Stevens, Ian R. E-mail: jgl@phys.hawaii.edu E-mail: w.h.edmondson@bham.ac.uk E-mail: wditto@hawaii.edu E-mail: irs@star.sr.bham.ac.uk
2015-01-01
Learned et al. proposed that a sufficiently advanced extra-terrestrial civilization may tickle Cepheid and RR Lyrae variable stars with a neutrino beam at the right time, thus causing them to trigger early and jogging the otherwise very regular phase of their expansion and contraction. This would turn these stars into beacons to transmit information throughout the galaxy and beyond. The idea is to search for signs of phase modulation (in the regime of short pulse duration) and patterns, which could be indicative of intentional, omnidirectional signaling. We have performed such a search among variable stars using photometric data from the Kepler space telescope. In the RRc Lyrae star KIC 5520878, we have found two such regimes of long and short pulse durations. The sequence of period lengths, expressed as time series data, is strongly autocorrelated, with correlation coefficients of prime numbers being significantly higher (p = 99.8%). Our analysis of this candidate star shows that the prime number oddity originates from two simultaneous pulsation periods and is likely of natural origin. Simple physical models elucidate the frequency content and asymmetries of the KIC 5520878 light curve. Despite this SETI null result, we encourage testing of other archival and future time-series photometry for signs of modulated stars. This can be done as a by-product to the standard analysis, and can even be partly automated.
Localization length of nearly periodic layered metamaterials
del Barco, O
2015-01-01
We have analyzed numerically the localization length of light $\\xi$ for nearly periodic arrangements of homogeneous stacks (formed exclusively by right-handed materials) and mixed stacks (with alternating right and left-handed metamaterials). Layers with index of refraction $n_1$ and thickness $L_1$ alternate with layers of index of refraction $n_2$ and thickness $L_2$. Positional disorder has been considered by shifting randomly the positions of the layer boundaries with respect to periodic values. For homogeneous stacks, we have shown that the localization length is modulated by the corresponding bands and that $\\xi$ is enhanced at the center of each allowed band. In the limit of long-wavelengths $\\lambda$, the parabolic behavior previously found in purely disordered systems is recovered, whereas for $\\lambda \\ll L_1 + L_2$ a saturation is reached. In the case of nearly periodic mixed stacks with the condition $|n_1 L_1|=|n_2 L_2|$, instead of bands there is a periodic arrangement of Lorenztian resonances, ...
Utility Building Analysis Billing Period: NOV -2013
ELECTRICITY Consumption MUNICIPAL WATER Consumption 8 CCF STEAM Consumption CHILLED WATER Consumption GAS Building Analysis Billing Period: NOV - 2013 032 JACKSON HALL: 150,393 Square Feet ELECTRICITY Consumption,550 Square Feet ELECTRICITY Consumption 114,185 KWHRS MUNICIPAL WATER Consumption 1,423 CCF STEAM Consumption
Giovannetti, Vittorio
We give a consistent quantum description of time, based on Page and Wootters’s conditional probabilities mechanism, which overcomes the criticisms that were raised against similar previous proposals. In particular we show ...
Unknown
2011-09-05
-1 THE PREDICTION OF BUS ARRIVAL TIME USING AUTOMATIC VEHICLE LOCATION SYSTEMS DATA A Dissertation by RAN HEE JEONG Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of DOCTOR OF PHILOSOPHY December 2004 Major Subject: Civil Engineering THE PREDICTION OF BUS ARRIVAL TIME USING AUTOMATIC VEHICLE LOCATION SYSTEMS DATA A Dissertation by RAN HEE JEONG Submitted to Texas A...
Magnetic field gradients in solar wind plasma and geophysics periods
A. Bershadskii
2006-11-16
Using recent data obtained by Advanced Composition Explorer (ACE) the pumping scale of the magnetic field gradients of the solar wind plasma has been calculated. This pumping scale is found to be equal to 24h $\\pm$ 2h. The ACE spacecraft orbits at the L1 libration point which is a point of Earth-Sun gravitational equilibrium about 1.5 million km from Earth. Since the Earth's magnetosphere extends into the vacuum of space from approximately 80 to 60,000 kilometers on the side toward the Sun the pumping scale cannot be a consequence of the 24h-period of the Earth's rotation. Vise versa, a speculation is suggested that for the very long time of the coexistence of Earth and of the solar wind the weak interaction between the solar wind and Earth could lead to stochastic synchronization between the Earth's rotation and the pumping scale of the solar wind magnetic field gradients. This synchronization could transform an original period of the Earth's rotation to the period close to the pumping scale of the solar wind magnetic field gradients.
Elsevier Journal Specific Embargo Periods 2013 Journal Name Issn Embargo Period
Ayala-Rincón, Mauricio
Elsevier Journal Specific Embargo Periods 2013 Journal Name Issn Embargo Period ACADEMIC PEDIATRICS 18762859 12 ACADEMIC RADIOLOGY 10766332 12 ACC CARDIOSOURCE REVIEW JOURNAL 15568571 12 ACCIDENT ANALYSIS 18759637 24 AEROSPACE SCIENCE AND TECHNOLOGY 12709638 24 AESTHETIC SURGERY JOURNAL 1090820X 12 AESTHETISCHE
Periodically-driven quantum matter: the case of resonant modulations
N. Goldman; J. Dalibard; M. Aidelsburger; N. R. Cooper
2015-03-06
Quantum systems can show qualitatively new forms of behavior when they are driven by fast time-periodic modulations. In the limit of large driving frequency, the long-time dynamics of such systems can often be described by a time-independent effective Hamiltonian, which is generally identified through a perturbative treatment. Here, we present a general formalism that describes time-modulated physical systems, in which the driving frequency is large, but resonant with respect to energy spacings inherent to the system at rest. Such a situation is currently exploited in optical-lattice setups, where superlattice (or Wannier-Stark-ladder) potentials are resonantly modulated so as to control the tunneling matrix elements between lattice sites, offering a powerful method to generate artificial fluxes for cold-atom systems. The formalism developed in this work identifies the basic ingredients needed to generate interesting flux patterns and band structures using resonant modulations. Additionally, our approach allows for a simple description of the micro-motion underlying the dynamics; we illustrate its characteristics based on diverse dynamic-lattice configurations. It is shown that the impact of the micro-motion on physical observables strongly depends on the implemented scheme, suggesting that a theoretical description in terms of the effective Hamiltonian alone is generally not sufficient to capture the full time-evolution of the system.
Multi-period Optimal Procurement and Demand Responses in the Presence of Uncertain Supply
Wierman, Adam
Multi-period Optimal Procurement and Demand Responses in the Presence of Uncertain Supply Libin markets, uncertainty in renewable generation, and real-time dynamic demand response. A load-serving entity day-ahead decision, propose real-time demand response algorithm, and study the effect of volume
Real-Time Task Scheduling under Thermal Constraints
Ahn, Youngwoo
2010-10-12
periodic tasks and non-real-time, but latency-sensitive, aperiodic jobs. We first introduce the Transient Overclocking Server, which safely reduces the response time of aperiodic jobs in the presence of hard real-time periodic tasks and thermal constraints...
The Super Period Matrix With Ramond Punctures
Edward Witten
2015-01-11
We generalize the super period matrix of a super Riemann surface to the case that Ramond punctures are present. For a super Riemann surface of genus g with 2r Ramond punctures, we define, modulo certain choices that generalize those in the classical theory (and assuming a certain generic condition is satisfied), a g|r x g|r period matrix that is symmetric in the Z_2-graded sense. As an application, we analyze the genus 2 vacuum amplitude in string theory compactifications to four dimensions that are supersymmetric at tree level. We find an explanation for a result that has been found in orbifold examples in explicit computations by D'Hoker and Phong: with their integration procedure, the genus 2 vacuum amplitude always vanishes "pointwise" after summing over spin structures, and hence is given entirely by a boundary contribution.
Beat Cepheid Period Ratios from OPAL Opacities
S. M. Morgan; D. L. Welch
1997-06-26
The discovery of a large number of beat Cepheids in the Large Magellanic Cloud in the MACHO survey, provides an opportunity to compare the characteristics of such Cepheids over a range of metallicities. We produced a large grid of linear nonadiabatic pulsation models using the OPAL opacity tables and with compositions corresponding to those of the Milky Way, and the Large and Small Magellanic Clouds. Using the relationship between the period ratio and the main pulsation period, we are able to define a range of models which correspond to the observed beat Cepheids, and thereby constrain the physical characteristics of the LMC beat Cepheids. We are also able to make some predictions about the nature of the yet-to-be-discovered SMC beat Cepheids.
Nicholson, Bruce J.
1 of 3 Time Limitation on Direct Subsidized Loan Eligibility for First- Time Borrowers on or after July 1, 2013 Maximum eligibility period to receive Direct Subsidized Loans There is a limit on the maximum period of time (measured in academic years) that you can receive Direct Subsidized Loans
Policy Flash 2013-41 Contracts Periods of Performance Exceeding...
1 Contracts Periods of Performance Exceeding 5 Years Policy Flash 2013-41 Contracts Periods of Performance Exceeding 5 Years Attached is Policy Flash 2013-41 Contracts Periods of...
Outburst-related period changes of recurrent nova CI aquilae
Wilson, R. E.; Honeycutt, R. K., E-mail: honey@astro.indiana.edu, E-mail: rewilson@ufl.edu [Astronomy Department, Indiana University, Swain Hall West, Bloomington, IN 47405 (United States)
2014-11-01
Pre-outburst and post-outburst light curves and post-outburst eclipse timings are analyzed to measure any period (P) change related to nova CI Aql's outburst of early 2000 and a mean post-outburst dP/dt, which then lead to estimates of the accreting component's rate of mass (M) change and its overall outburst-related change of mass over roughly a decade of observations. We apply a recently developed procedure for unified analysis of three timing-related data types (light curves, radial velocities, and eclipse timings), although with only light curves and timings in this case. Fits to the data are reasonably good without need for a disk in the light-curve model, although the disk certainly exists and has an important role in our post-outburst mass flow computations. Initial experiments showed that, although there seems to be an accretion hot spot, it has essentially no effect on derived outburst-related ?P or on post-outburst dP/dt. Use of atomic time (HJED) in place of HJD also has essentially nil effect on ?P and dP/dt. We find ?P consistently negative in various types of solutions, although at best only marginally significant statistically in any one experiment. Pre-outburst HJD {sub 0} and P results are given, as are post-outburst HJD {sub 0}, P, and dP/dt, with light curves and eclipse times as joint input, and also with only eclipse time input. Post-outburst dP/dt is negative at about 2.4?. Explicit formulae for mass transfer rates and epoch-to-epoch mass change are developed and applied. A known offset in the magnitude zero point for 1991-1994 is corrected.
Short-period X-ray oscillations in super-soft novae and persistent SSS
Ness, J -U; Osborne, J P; Kuulkers, E; Henze, M; Piro, A L; Drake, J J; Dobrotka, A; Schwarz, G; Starrfield, S; Kretschmar, P; Hirsch, M; Wilms, J
2015-01-01
Transient short-period <100s oscillations have been found in the X-ray light curves of three novae during their SSS phase and in one persistent SSS. We pursue an observational approach to determine possible driving mechanisms and relations to fundamental system parameters such as the white dwarf mass. We performed a systematic search for short-period oscillations in all available XMM-Newton and Chandra X-ray light curves of persistent SSS and novae during their SSS phase. To study time evolution, we divided each light curve into short time segments and computed power spectra. We then constructed dynamic power spectra from which we identified transient periodic signals even when only present for a short time. From all time segments of each system, we computed fractions of time when periodic signals were detected. In addition to the previously known systems with short-period oscillations, RS Oph (35s), KT Eri (35s), V339 Del (54s), and Cal 83 (67s), we found one additional system, LMC 2009a (33s), and also c...
Microsoft Word - Alcoa Extended Initial Period ROD - 2010-10...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Extended Initial Period... 6 b. Benefits to BPA will equal or exceed costs for the Extended Initial Period of the Block Contract. ......
DOE Extends Public Comment Period for the Draft Uranium Leasing...
Extends Public Comment Period for the Draft Uranium Leasing Program Programmatic Environmental Impact Statement DOE Extends Public Comment Period for the Draft Uranium Leasing...
Comparison of quantization of charge transport in periodic and open pumps
Gian Michele Graf; Gregorio Ortelli
2007-09-19
We compare the charges transported in two systems, a spatially periodic and an open quantum pump, both depending periodically and adiabatically on time. The charge transported in a cycle was computed by Thouless, respectively by Buttiker et al. in the two cases. We show that the results agree in the limit where the two physical situations become the same, i.e., that of a large open pump.
Time-resolved photometry of cataclysmic variables
C. Papadaki; H. M. J. Boffin; J. Cuypers; V. Stanishev; Z. Kraicheva; V. Genkov
2003-12-18
We present time-resolved photometry of two cataclysmic variables whose CCD photometric observations were obtained with the 1m telescope at the South African Astronomical Observatory in October 2002 and August 2003 and with the 1m telescope at Hoher List in Germany. Concerning MCT 2347-3144 we detect for the first time a period of 6.65h. For V1193 Ori the 3.96 h periodicity has for the first time been confirmed through time-resolved photometry.
Timing the Parkes Multibeam Pulsars
R. N. Manchester; A. G. Lyne; F. Camilo; V. M. Kaspi; I. H. Stairs; F. Crawford; D. J. Morris; J. F. Bell; N. D'Amico
1999-11-17
Measurement of accurate positions, pulse periods and period derivatives is an essential follow-up to any pulsar survey. The procedures being used to obtain timing parameters for the pulsars discovered in the Parkes multibeam pulsar survey are described. Completed solutions have been obtained so far for about 80 pulsars. They show that the survey is preferentially finding pulsars with higher than average surface dipole magnetic fields. Eight pulsars have been shown to be members of binary systems and some of the more interesting results relating to these are presented.
IUPAC Periodic Table of Isotopes for the Educational Community
Holden N. E.; Holden,N.E.; Coplen,T.B.
2012-07-15
John Dalton first proposed the concept of atomic weights of the elements in the first decade of the nineteenth century. These atomic weights of the chemical elements were thought of as constants of nature, similar to the speed of light. Dmitri Mendeleev arranged the atomic weights of the elements in ascending order of value and used the systematic variation of their chemical properties to produce his Periodic Table of the Elements in 1869. Measurement of atomic weight values became an important chemical activity for a century and a half. Theodore Richards received a Noble Prize for his work in this area. In 1913, Fredrick Soddy found a species of radium, which had an atomic weight value of 228, compared to the familiar radium gas value of 226. Soddy coined the term 'isotope' (Greek for 'in the same place') to account for this second atomic weight value in the radium position of the Periodic Table. Both of these isotopes of radium are radioactive. Radioactive isotopes are energetically unstable and will decay (disintegrate) over time. The time it takes for one half of a sample of a given radioactive isotope to decay is the half-life of that isotope. In addition to having different atomic weight values, radium-226 and radium-228 also have different half-life values. Around the same time as Soddy's work, J.J. Thomson (discoverer of the electron) identified two stable (non-radioactive) isotopes of the same element, neon. Over the next 40 years, the majority of the known chemical elements were found to have two or more stable (or long-lived radioactive isotopes that contribute significantly to the determination of the atomic weights of the elements).
Down-hole periodic seismic generator
Hardee, H.C.; Hills, R.G.; Striker, R.P.
1982-10-28
A down hole periodic seismic generator system is disclosed for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.
Fukuyama, T.; Shirahama, H. [Faculty of Education, Ehime University, Bunkyo-cho 3, Matsuyama, Ehime 790-8577 (Japan); Watanabe, Y.; Kawai, Y. [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasugakoen 6-1, Kasuga, Fukuoka 816-8580 (Japan); Taniguchi, K. [Department of Physics, Kyoto University of Education, Fujinomori-cho 1, Fukakusa, Fushimi-ku, Kyoto 612-8522 (Japan)
2006-07-15
Time-delayed feedback is applied to the motions associated with the nonlinear periodic regime generated due to current-driven ion acoustic instability; this is a typical instability in a laboratory plasma, and the dynamical behavior is experimentally investigated using delayed feedback. A time-delayed autosynchronization method is applied. When delayed feedback is applied to the nonlinear periodic orbit, the periodic state changes to various motions depending on the control parameters, namely, the arbitrary time delay and the proportionality constant. Lyapunov exponents are calculated in order to examine the dynamical behavior.
Electromagnetic Siegert states for periodic dielectric structures
Friends R. Ndangali; Sergei V. Shabanov
2011-08-09
The formalism of Siegert states to describe the resonant scattering in quantum theory is extended to the resonant scattering of electromagnetic waves on periodic dielectric arrays. The excitation of electromagnetic Siegert states by an incident wave packet and their decay is studied. The formalism is applied to develop a theory of coupled electromagnetic resonances arising in the electromagnetic scattering problem for two such arrays separated by a distance 2h (or, generally, when the physical properties of the scattering array depend on a real coupling parameter h). Analytic properties of Siegert states as functions of the coupling parameter h are established by the Regular Perturbation Theorem which is an extension the Kato-Rellich theorem to the present case. By means of this theorem, it is proved that if the scattering structure admits a bound state in the radiation continuum at a certain value of the coupling parameter h, then there always exist regions within the structure in which the near field can be amplified as much as desired by adjusting the value of h. This establishes a rather general mechanism to control and amplify optical nonlinear effects in periodically structured planar structures possessing a nonlinear dielectric susceptibility.
Quarterly Construction Status Report Period Ending: December 31, 2014
Alpay, S. Pamir
Cast Stone Replacement 901833 Quarterly Construction Status Report for Period Ending: December 31, 2014
A field expansions method for scattering by periodic multilayered media
Malcolm, Alison E.
2010-01-01
The interaction of acoustic and electromagnetic waves with periodic structures plays an important role
Xifeng Su; Lei Zhang; Rafael de la Llave
2015-03-11
We consider 1-D quasi-periodic Frenkel-Kontorova models (describing, for example, deposition of materials in a quasi-periodic substratum). We study the existence of equilibria whose frequency (i.e. the inverse of the density of deposited material) is resonant with the frequencies of the substratum. We study perturbation theory for small potential. We show that there are perturbative expansions to all orders for the quasi-periodic equilibria with resonant frequencies. Under very general conditions, we show that there are at least two such perturbative expansions for equilibria for small values of the parameter. We also develop a dynamical interpretation of the equilibria in these quasi-periodic media. We show that the dynamical system has very unusual properties. Using these, we obtain results on the Lyapunov exponents of the resonant quasi-periodic solutions. In a companion paper, we develop a rather unusual KAM theory (requiring new considerations) which establishes that the perturbative expansions converge when the perturbing potentials satisfy a one-dimensional constraint.
Aydin, Hakan
for efficient power- aware design and dynamic power monitoring techniques. Solar- and nuclear-powered systems such as the ACPI (Advanced COP figuration and Power Interface) [I11 for power manage- ment of laptop computers,his technique remains sub-optima.1, even for a system with perfect, knowledge of idle intervals. In other words
Collins, Kimberlee C. (Kimberlee Chiyoko)
2015-01-01
Studies of non-diffusive heat conduction provide insight into the fundamentals of heat transport in condensed matter. The mean free paths (MFPs) of phonons that are most important for conducting heat are well represented ...
Extracting unstable periodic orbits from chaotic time series data Paul So,1,2
Roberts, Stephen
, D.C. 20010 2 Institute for Plasma Research, University of Maryland, College Park, Maryland 20742 3
Periodic Charging Scheme for Fixed-Priority Real-Time Systems with Renewable Energy
Aydin, Hakan
, the deployed systems use solar panels and piezoelectric units, that exploit solar energy and mechani- cal research and development area. In the last decade, power-aware resource management and scheduling of the day and season in the case of solar energy); but its rate of supply is not necessarily uniform
Systems for optimizing the condition of beef carcasses for distribution over extended time periods
Simmons, Ronald Douglas
1974-01-01
of simulated nitrogen gas atmospheres in comparison to normal air atmospheres for beef storage. Eighty beef sides were divided into quarters and subjected to one of eight treatments 48 hr postmortem. Two kinds of surface protection (unprotected vs. PVC film... wrapping), two rinsing treat- ments (200 ppm chlorine vs. no chlorine rinse), two types of atmos- phere (air vs. nitrogen gas) and two storage intervals (14 vs. 21 days) were compared. Analysis of variance revealed that wrapping in PVC film, rinsing...
Automatic and Accurate Determination of the Onset Time of the Quasi-periodic Oscillation
Higuchi, Tomoyuki
Higuchi The Institute of Statistical Mathematics, 4-6-7 Minami-Azabu, Minato-ku, Tokyo 106-8569 Japan eld observation is usually carried out by focusing on a wave- like component obtained by applying on a simple modi - cation of the wavelet analysis, always generates a pseudo precursor prior to a true onset
Time series study of urban rainfall suppression during clean-up periods
Geng, Jun
2009-05-15
The effect on urban rainfall of pollution aerosols is studied both by data analysis and computational simulation. Our study examines data for urban areas undergoing decadal clean-up. We compare the annual precipitation between polluted sites...
Time series study of urban rainfall suppression during clean-up periods
Geng, Jun
2008-10-10
. Effects of Pollutant Aerosols on Precipitation……………….... 3 3. Our Focus………………………………………………………. 6 II STUDY OF SUPPRESSION OF PRECIPITATION IN AIR POLLUTIONS BY ANALYZING DATA FROM...)......................................................................................... 21 6 Trends of ratio of annual precipitation amount of Culver City (CC) and Pasadena (PA)...................................................................................... 23 7 The relationship between precipitation and TSP...
22 March 2012 Employee Information Lost Time No Lost Time Modified Duties
Machel, Hans
22 March 2012 Employee Information Lost Time No Lost Time Modified Duties Last Name First Name the injured worker have personal coverage? Yes No Is the injured worker a partner or director in this business OR Did this condition develop over a period of time? Yes No Hours of employment on the day of accident
Single-periodic-film optical bandpass filter
Niraula, Manoj; Magnusson, Robert
2015-01-01
Resonant periodic surfaces and films enable new functionalities with wide applicability in practical optical systems. Their material sparsity, ease of fabrication, and minimal interface count provide environmental and thermal stability and robustness in applications. Here we report an experimental bandpass filter fashioned in a single patterned layer on a substrate. Its performance corresponds to bandpass filters requiring perhaps 30 traditional thin-film layers as shown by an example. We demonstrate an ultra-narrow, high-efficiency bandpass filter with extremely wide, flat, and low sidebands. This class of devices is designed with rigorous solutions of the Maxwell equations while engaging the physical principles of resonant waveguide gratings. The proposed technology is integration-friendly and opens doors for further development in various disciplines and spectral regions where thin-film solutions are traditionally applied.
Imtak Jeon; Neil Lambert; Paul Richmond
2012-11-29
We consider periodic arrays of M2-branes in the ABJM model in the spirit of a circle compactification to D2-branes in type IIA string theory. The result is a curious formulation of three-dimensional maximally supersymmetric Yang-Mills theory in terms of fermions, seven transverse scalars, a non-dynamical gauge field and an additional scalar `dual gluon'. Upon further T-duality on a transverse torus we obtain a non-manifest-Lorentz-invariant description of five-dimensional maximally supersymmetric Yang-Mills. Here the additional scalar field can be thought of as the components of a two-form along the torus. This action can be viewed as an M-theory description of M5-branes on ${\\mathbb T}^3$.
Chaotic dynamics in a periodically driven spin-1 condensate
Cheng Jing [Department of Physics, South China University of Technology, Guangzhou 510640 (China); Kavli Institute for Theoretical Physics China, CAS, Beijing 100190 (China)
2010-02-15
We use periodically modulated magnetic fields to drive spin-1 Bose-Einstein condensates (BECs) and study the corresponding spin-mixing dynamics. Due to the time-dependent driving, this system permits chaotic dynamics depending on the drive parameters, which could not occur in previous studies. From the investigation of the Poincare sections, we find there exist complex trajectories in the phase space, leading to very complicated structures of the phase space with mixed regular and chaotic regions. By calculating the quasienergy levels of the corresponding Floquet operators, the signatures of quantum chaos are also found in this system. The level spacing distribution is very close to the Poisson distribution or Wigner distribution when the corresponding classical dynamics is regular or chaotic.
Instrumentation to Monitor Transient Developing Periodic Flow in Newtonian Slurries
Bamberger, Judith A.; Enderlin, Carl W.
2014-08-03
This paper describes measurement techniques developed and applied to characterize solids mobilization and mixing of Newtonian slurries that are subjected to transient, periodic, developing flows. Metrics to characterize mobilization and mixing are the just suspended velocity (UJS) and the cloud height (HC). Two ultrasonic instruments to characterize pulse jet mixing of slurries were developed and deployed to measure related metrics: the thickness of the settled bed (used to determine mobilization) and the concentration within the cloud as a function of elevation [C(Z)]. A second method, continuous sample extraction, characterization, and reinsertion was successfully used to measure average density and characterize the concentration within the cloud. Testing focused on mixing vessels using intermitent jet mixers oriented vertically downward. Descriptions of the instruments and instrument performance are presented. These techniques were an effective approach to characterize mixing phenomena, determine mixing energy required to fully mobilize vessel contents, and to determine mixing times for process evaluation.
Harrison, Thomas
-PERIOD CATACLYSMIC VARIABLES Thomas E. Harrison1,2 and Heather L. Osborne2 Department of Astronomy, New Mexico State) found that the carbon abundance was 5 times solar, nitrogen was 3 times solar, and silicon was less than 0.1 times solar for the white
Count-doubling time safety circuit
Rusch, Gordon K. (Downers Grove, IL); Keefe, Donald J. (Lemont, IL); McDowell, William P. (Downers Grove, IL)
1981-01-01
There is provided a nuclear reactor count-factor-increase time monitoring circuit which includes a pulse-type neutron detector, and means for counting the number of detected pulses during specific time periods. Counts are compared and the comparison is utilized to develop a reactor scram signal, if necessary.
Dispatch R427 Time perception: Brain time or event time?
Johnston, Alan
Dispatch R427 Time perception: Brain time or event time? Alan Johnston* and Shin'ya Nishida Recent experiments show that synchronous events can appear to an observer to occur at different times. Neural processing time delays are offered as an explanation of these temporal illusions, but equating perceived time
Mondrik, Nicholas; Marshall, Jennifer L
2015-01-01
We present a new method of extending the single band Analysis of Variance period estimation algorithm to multiple bands. We use SDSS Stripe 82 RR Lyrae to show that in the case of low number of observations per band and non-simultaneous observations, improvements in period recovery rates of up to $\\approx$60\\% are observed. We also investigate the effect of inter-band observing cadence on period recovery rates. We find that using non-simultaneous observation times between bands is ideal for the multiband method, and using simultaneous multiband data is only marginally better than using single band data. These results will be particularly useful in planning observing cadences for wide-field astronomical imaging surveys such as LSST. They also have the potential to improve the extraction of transient data from surveys with few ($\\lesssim 30$) observations per band across several bands, such as the Dark Energy Survey.
Time Management Managing Time and Tasks
Kunkle, Tom
Time Management Managing Time and Tasks What is time management? Time can't be managed Â but you can manage the amount of time you use each day for fun, work, rest, and time spent with others. Why is time management important? You have responsibilities to yourself, to your family and friends, to your
Tonn, Bruce Edward; Rose, Erin M; Schmoyer, Richard L; Eisenberg, Joel Fred; Ternes, Mark P; Schweitzer, Martin; Hendrick, Timothy P
2012-08-01
This report describes the third major evaluation of the Program, encompassing program years 2009 to 2011. In this report, this period of time is referred to as the ARRA Period. This is a special period of time for the Program because the American Recovery and Reinvestment Act (ARRA) of 2009 has allocated $5 billion of funding for the Program. In normal program years, WAP s annual appropriation is in the range of $200-250 million, supporting the weatherization of approximately 100,000 homes. With the addition of ARRA funding during these program years, the expectation is that weatherization activity will exceed 300,000 homes per year. In addition to saving energy and reducing low-income energy bills, expanded WAP funding is expected to stimulate the economy by providing new jobs in the weatherization field and allowing low-income households to spend more money on goods and services by spending less on energy.
Periods and damping rates of fast sausage oscillations in multi-shelled coronal loops
Chen, Shao-Xia; Xia, Li-Dong; Yu, Hui
2015-01-01
Standing sausage modes are important in interpreting quasi-periodic pulsations in the lightcurves of solar flares. Their periods and damping times play an important role in seismologically diagnosing key parameters like the magnetic field strength in regions where flare energy is released. Usually such applications are based on theoretical results neglecting unresolved fine structures in magnetized loops. However, the existence of fine structuring is suggested on both theoretical and observational grounds. Adopting the framework of cold magnetohydrodynamics (MHD), we model coronal loops as magnetized cylinders with a transverse equilibrium density profile comprising a monolithic part and a modulation due to fine structuring in the form of concentric shells. The equation governing the transverse velocity perturbation is solved with an initial-value-problem approach, and the effects of fine structuring on the periods $P$ and damping times $\\tau$ of global, leaky, standing sausage modes are examined. A parameter...
A Low-Power Acoustic Periodicity Detector Chip for Voice and Engine Detection
Horiuchi, Timothy K.
designed a simple, low-power (1.5 Wµ ) analog VLSI circuit that detects periodicity in the time. This algorithm rejects impulse events, wind noise, and is intensity- independent. Clearly, as this type into the chip to a peak-detector/spike-generator circuit. The `spike generator' generates a voltage spike
the past 150-year period of reported global Second, historical information on solar
compared with the radia- tive relaxation time of layers storing the heat blocked by sunspots. This timethe past 150-year period of reported global warming. Second, historical information on solar increase in solar activity beyond present levels might make the sun dimmer, decreasing its average out- put
A PERIOD-BASED GROUP MEMBERSHIP STRATEGY FOR NODES OF TDMA NETWORKS
Koopman, Philip
In automotive embedded systems, all nodes are not created equal. Automotive embedded systems generally have different periods. Current automotive buses such as the Controller Area Network (CAN) use a priority in order to provide a more predictable platform for safety assurance. Time Division Multiple Access (TDMA
FILAMENT DISAPPEARANCES DURING THE PERIOD OF SEPTEMBER 1991 THROUGH SEPTEMBER 1994
FILAMENT DISAPPEARANCES DURING THE PERIOD OF SEPTEMBER 1991 THROUGH SEPTEMBER 1994 HAIMIN WANG1 of the disappearing solar filaments based on this set of data are made: (1) The disk latitude distribution of all larger disappearing filaments with a minimum length of 70 arc sec, including the time
Small angle neutron scattering on periodically deformed polymers A. R. Rennie
Boyer, Edmond
765 Small angle neutron scattering on periodically deformed polymers A. R. Rennie Institut für Phys-768 SEPTEMBRE 1984, 1. Introduction. Neutron scattering has proved a useful tool for the investigation of a wide time for a small angle neutron scattering spectrum is several minutes. Obser- vation on rapidly
Lab 7: Fourier analysis and synthesis Fourier series (periodic phenomena)
Gustafsson, Torgny
Lab 7: Fourier analysis and synthesis · Fourier series (periodic phenomena) · Fourier transform (aperiodic phenomena) · Fast Fourier transform (FFT) The Fourier Transform and its Applications Brad G A powerful analytic tool that has many applications.... #12;Applications of Fourier analysis Periodic
Entrainment control of chaos near unstable periodic orbits
R. Mettin
1996-10-16
It is demonstrated that improved entrainment control of chaotic systems can maintain periodic goal dynamics near unstable periodic orbits without feedback. The method is based on the optimization of goal trajectories and leads to small open-loop control forces.
Benjamin Hertz Shargel; Tom Chou
2009-07-27
Asymptotic fluctuation theorems are statements of a Gallavotti-Cohen symmetry in the rate function of either the time-averaged entropy production or heat dissipation of a process. Such theorems have been proved for various general classes of continuous-time deterministic and stochastic processes, but always under the assumption that the forces driving the system are time independent, and often relying on the existence of a limiting ergodic distribution. In this paper we extend the asymptotic fluctuation theorem for the first time to inhomogeneous continuous-time processes without a stationary distribution, considering specifically a finite state Markov chain driven by periodic transition rates. We find that for both entropy production and heat dissipation, the usual Gallavotti-Cohen symmetry of the rate function is generalized to an analogous relation between the rate functions of the original process and its corresponding backward process, in which the trajectory and the driving protocol have been time-reversed. The effect is that spontaneous positive fluctuations in the long time average of each quantity in the forward process are exponentially more likely than spontaneous negative fluctuations in the backward process, and vice-versa, revealing that the distributions of fluctuations in universes in which time moves forward and backward are related. As an additional result, the asymptotic time-averaged entropy production is obtained as the integral of a periodic entropy production rate that generalizes the constant rate pertaining to homogeneous dynamics.
Extending quantum control of time-independent systems to time-dependent systems
Zhen-Yu Wang; Ren-Bao Liu
2011-01-27
We establish that if a scheme can control a time-independent system arbitrarily coupled to a generic finite bath over a short period of time $T$ with control precision $O(T^{N+1})$, it can also realize the control with the same order of precision on smoothly time-dependent systems. This result extends the validity of various universal dynamical control schemes to arbitrary analytically time-dependent systems.
Long Term Simulations Of Astrophysical Jets; Energy Structure and Quasi-Periodic Ejection
Ahmed Ibrahim; Kazunari Shibata
2007-04-23
We have performed self-consistent 2.5-dimensional nonsteady MHD numerical simulations of jet formation as long as possible, including the dynamics of accretion disks. Although the previous nonsteady MHD simulations for astrophysical jets revealed that the characteristics of nonsteady jets are similar to those of steady jets, the calculation time of these simulations is very short compared with the time scale of observed jets. Thus we have investigated long term evolutions of mass accretion rate, mass outflow rate, jet velocity, and various energy flux. We found that the ejection of jet is quasi-periodic. The period of the ejection is related to the time needed for the initial magnetic filed to be twisted to generate toroidal filed. We compare our results with both the steady state theory and previous 2.5-dimensional nonsteady MHD simulations.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
UGE Scheduler Cycle Time UGE Scheduler Cycle Time Genepool Cycle Time Genepool Daily Genepool Weekly Phoebe Cycle Time Phoebe Daily Phoebe Weekly What is the Scheduler Cycle? The...
The quasi-periodic nature of wall slip for molten plastics in large amplitude oscillatory shear
Adrian, David Warren
1992-01-01
is not to be confused with a quasi-periodic spectrum like Figure 15 because of its strong continuous component. 0. 01 X 0. 001 0. 0001 0. 2 0. 4 0. 6 f (Hz) Figure 14. Chaotic amplitude spectrum of Duffing's equation. 0. 1 0. 01 X 0. 001 0. 0001 1E-05 0... amplitude spectrum for a viscoelastic melt in LAOS 6. Pipkin diagram, adapted from Dealy and Wissbrun (1990), 14 showing the regimes of oscillatory shear for a viscoelastic melt . . . . 15 7. Time domain plot of the quasi-periodic forced van der Pol...
Complete Chaotic Mixing in an Electro-osmotic Flow by Destabilization of Key Periodic Pathlines
R. Chabreyrie; C. Chandre; P. Singh; N. Aubry
2011-02-07
The ability to generate complete, or almost complete, chaotic mixing is of great interest in numerous applications, particularly for microfluidics. For this purpose, we propose a strategy that allows us to quickly target the parameter values at which complete mixing occurs. The technique is applied to a time periodic, two-dimensional electro-osmotic flow with spatially and temporally varying Helmoltz-Smoluchowski slip boundary conditions. The strategy consists of following the linear stability of some key periodic pathlines in parameter space (i.e., amplitude and frequency of the forcing), particularly through the bifurcation points at which such pathlines become unstable.
Time and Labor Manual -Time Keepers -LSUSH
Time and Labor Manual - Time Keepers - LSUSH Version Date: July 2012 #12;COPYRIGHT & TRADEMARKS create a risk of personal injury. If you use this software in dangerous applications, then you shall Guide Time and Labor Manual - Time Keepers - LSUSH Page iii Table of Contents Time and Labor Manual
Time Commitments Where Does Your Time Go
Kunkle, Tom
Time Commitments Where Does Your Time Go Everyone starts the week with the same number of hours. So, why does your time go so fast? Let's find out! Number of hours of sleep each night ____ x 7 preparation/clean-up time) ____ x 7 = ____ Travel time to and from campus ___ x __ = ____ Number of hours per
Horizontal structure of winter time 250 mb jet stream variations on the fifteen day time scale
Park, Sangwook
1993-01-01
The horizontal structure of the 250 mb jet stream on the fifteen-day time scale during Northern Hemisphere winter is presented. The winter season is divided into six fifteen-day periods for the 24-year NMC data set. The fifteen-day time...
A one-time excess inventory disposal decision under stochastic and price dependent demand
Zhu, Xiaoyan
2002-01-01
This thesis studies a one-time excess inventory disposal problem where the demand during the disposal period (DDDP) is stochastic and its distribution depends on the disposal price. More specifically, this thesis considers a periodic...
THE DECAYING LONG-PERIOD OSCILLATION OF A STELLAR MEGAFLARE
Anfinogentov, S.; Nakariakov, V. M.; Mathioudakis, M.; Van Doorsselaere, T.; Kowalski, A. F.
2013-08-20
We analyze and interpret the oscillatory signal in the decay phase of the U-band light curve of a stellar megaflare observed on 2009 January 16 on the dM4.5e star YZ CMi. The oscillation is well approximated by an exponentially decaying harmonic function. The period of the oscillation is found to be 32 minutes, the decay time about 46 minutes, and the relative amplitude 15%. As this observational signature is typical of the longitudinal oscillations observed in solar flares at extreme ultraviolet and radio wavelengths, associated with standing slow magnetoacoustic waves, we suggest that this megaflare may be of a similar nature. In this scenario, macroscopic variations of the plasma parameters in the oscillations modulate the ejection of non-thermal electrons. The phase speed of the longitudinal (slow magnetoacoustic) waves in the flaring loop or arcade, the tube speed, of about 230 km s{sup -1} would require a loop length of about 200 Mm. Other mechanisms, such as standing kink oscillations, are also considered.
Periodicals collection management using a decision support system
Compton, M.L.; Moser, E.C.
1993-12-31
Sandia National Laboratories is a multiprogram national laboratory established in 1949. The Library currently uses DOBIS for its automated system, including the Periodicals Control function for periodical check-in. DOBIS performs processing and control functions adequately, but could not meet our reporting needs. Therefore the Library`s Periodicals Decision Team decided that they needed another ``system`` for collection management. A Periodicals Decision Support System was created using information downloaded from DOBIS and uploaded into dBASE IV. The Periodical Decision Support System functions as an information-processing system that has aided us in making collection management decisions for periodicals. It certainly allows us to do interactive ad-hoc analysis; although there are no modeling tools currently incorporated in the system. We hope that these modeling tools will come later. We have been gathering information and developing needed reports to achieve this goal.
Multilevel interference lithography--fabricating sub-wavelength periodic nanostructures
Chang, Chih-Hao, 1980-
2008-01-01
Periodic nanostructures have many exciting applications, including high-energy spectroscopy, patterned magnetic media, photonic crystals, and templates for self-assembly. Interference lithography (IL) is an attractive ...
Department of Energy Announces Plans for Additional Comment Period...
Office of Environmental Management (EM)
Department of Energy Announces Plans for Additional Comment Period on National Interest Electric Transmission Corridors Department of Energy Announces Plans for Additional Comment...
Extension of Comment Period on the Draft Integrated, Interagency...
of Comment Period on the Draft Integrated, Interagency Pre-Application (IIP) Process for Electric Transmission Projects Requiring Federal Authorizations Extension of Comment...
Analysis of Periodic GrowthDisturbance Models Timothy C. Reluga
Reluga, Tim
and may include forest fires, volcanic eruptions, and hurricanes, occur quickly, perhaps over a period succession around disturbances like forest fires. Andrewartha and Birch (1978) proposed that disturbances
EIS-0431: Extension of Public Comment Period | Department of...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Comment Period Hydrogen Energy California's Integrated Gasification Combined Cycle and Carbon Capture and Sequestration Project, CA The U.S. Department of Energy (DOE) published...
Quality of monitoring of stochastic events by periodic and ...
David K. Y. Yau, Nung Kwan Yip, Chris Y. T. Ma, Nageswara S. V. Rao, Mallikarjun Shankar
2010-08-28
sensor monitoring a PoI may be periodically turned off to conserve energy, thereby ... In traditional public safety work, policemen or security guards are on.
Quality of Monitoring of Stochastic Events by Periodic & Proportional ...
2008-12-09
be periodically turned off to conserve energy, thereby .... ing resources to the different parts in proportion ... riodically turn off the sensor to conserve energy, so.
EIS-0431: Extension of public comment period; Notice of public...
EIS-0431: Extension of public comment period; Notice of public hearing; Correction Hydrogen Energy California's Integrated Gasification Combined Cycle and Carbon Capture and...
Pulse vaccination in the periodic infection rate SIR epidemic model
Zhen Jin; Mainul Haque; Quanxing Liu
2006-06-09
A pulse vaccination SIR model with periodic infection rate $\\beta (t)$ have been proposed and studied. The basic reproductive number $R_0$ is defined. The dynamical behaviors of the model are analyzed with the help of persistence, bifurcation and global stability. It has been shown that the infection-free periodic solution is globally stable provided $R_0 1$. Standard bifurcation theory have been used to show the existence of the positive periodic solution for the case of $R_0 \\to1^+$. Finally, the numerical simulations have been performed to show the uniqueness and the global stability of the positive periodic solution of the system.
CEQ Extends Comment Period on Revised Draft Guidance on Consideration...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
on Revised Draft Guidance on Consideration of Greenhouse Gas Emissions and the Effects of Climate Change in NEPA Reviews CEQ Extends Comment Period on Revised Draft Guidance on...
DOE Extends Public Comment Period for Uranium Program Environmental...
Office of Environmental Management (EM)
Uranium Program Environmental Impact Statement DOE Extends Public Comment Period for Uranium Program Environmental Impact Statement April 18, 2013 - 1:08pm Addthis Contractor, Bob...
Guidance on the Required Period for Grantees to Obligate Funds...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
on the Required Period for Grantees to Obligate Funds and the Procedures for Reporting of Obligated Funds for the Energy Efficiency Conservation Block Grant (EECBG) Program...
Pressure-driven reconnection and quasi periodical oscillations in plasmas
Paccagnella, R., E-mail: roberto.paccagnella@igi.cnr.it [Consorzio RFX and Istituto Gas Ionizzati del Consiglio Nazionale delle Ricerche (CNR), Padova (Italy)
2014-03-15
This paper presents a model for an ohmically heated plasma in which a feedback exists between thermal conduction and transport, on one side, and the magneto-hydro-dynamical stability of the system, on the other side. In presence of a reconnection threshold for the magnetic field, a variety of periodical or quasi periodical oscillations for the physical quantities describing the system are evidenced. The model is employed to interpret the observed quasi periodical oscillations of electron temperature and perturbed magnetic field around the so called “Single Helical” state in the reversed field pinch, but its relevance for other periodical phenomena observed in magnetic confinement systems, especially in tokamaks, is suggested.
AN EFFICIENT SECOND ORDER IN TIME SCHEME FOR APPROXIMATING LONG TIME STATISTICAL PROPERTIES OF
AN EFFICIENT SECOND ORDER IN TIME SCHEME FOR APPROXIMATING LONG TIME STATISTICAL PROPERTIES of the following efficient second order in time scheme for the 2D Navier-Stokes equation in a periodic box: 3n+1 - 4n + n-1 2k + (2n - n-1 ) · (2n - n-1 ) - n+1 = fn+1 , -n = n . The scheme is a combination of a 2
Dwarf Nova-like Outburst of Short Period Intermediate Polar HT Camelopardalis
Ryoko Ishioka; Taichi Kato; Makoto Uemura; Gary W. Billings; Koichi Morikawa; Ken'ichi Torii; Kenji Tanabe; Arto Oksanen; Harri Hyvonen; Hitoshi Itoh
2002-06-12
We report the first time-series observations of the short outburst of the proposed intermediate polar HT Cam (=RX J0757.0+6306). On 2001 December 29, we detected the object was undergoing a bright outburst at the magnitude of $m_{vis}=12.2$. Following this detection, we started international joint observations through VSNET. The light curve showed a gradual decline for the first 0.5 d. Following this short plateau phase, the rate of decline dramatically increased to more than 4 mag d$^{-1}$. Within 1.5 d from the outburst detection, the object almost declined to the quiescent level. During the rapidly declining phase, long-term modulations with a period of 86 min and strong pulses with a period of 8.6 min were observed. We concluded that 86 min and 8.6 min are the orbital period and the spin period of HT Cam, respectively. By the detection of the spin period, we confirmed the IP classification of HT Cam. However, its outburst behavior rather resembles that of dwarf novae. The discrepancy between the declining rates of the total flux and the pulse flux strongly suggests that the disk instabilities were taking place during the outburst.
Discovery of four periodic methanol masers and updated light curve for a further one
Szymczak, M; Bartkiewicz, A
2015-01-01
We report the discovery of 6.7 GHz methanol maser periodic flares in four massive star forming regions and the updated light curve for the known periodic source G22.357+0.066. The observations were carried out with the Torun 32 m radio telescope between June 2009 and April 2014. Flux density variations with period of 120 to 245 d were detected for some or all spectral features. A variability pattern with a fast rise and relatively slow fall on time-scale of 30-60 d dominated. A reverse pattern was observed for some features of G22.357+0.066, while sinusoidal-like variations were detected in G25.411+0.105. A weak burst lasting ~520 d with the velocity drift of 0.24 km/s/yr occurred in G22.357+0.066. For three sources for which high resolution maps are available, we found that the features with periodic behaviour are separated by more than 500 au from those without any periodicity. This suggests that the maser flares are not triggered by large-scale homogeneous variations in either the background seed photon fl...
Oscillatory convective modes in red giants: a possible explanation of the long secondary periods
Saio, Hideyuki; Takayama, Masaki; Ita, Yoshifusa
2015-01-01
We discuss properties of oscillatory convective modes in low-mass red giants, and compare them with observed properties of the long secondary periods (LSPs) of semi-regular red giant variables. Oscillatory convective modes are very nonadiabatic g$^{-}$ modes and they are present in luminous stars, such as red giants with $\\log L/{\\rm L}_\\odot \\ga 3$. Finite amplitudes for these modes are confined to the outermost nonadiabatic layers, where the radiative energy flux is more important than the convective energy flux. The periods of oscillatory convection modes increase with luminosity, and the growth times are comparable to the oscillation periods. The LSPs of red giants in the Large Magellanic Cloud (LMC) are observed to lie on a distinct period-luminosity sequence called sequence D. This sequence D period-luminosity relation is roughly consistent with the predictions for dipole oscillatory convective modes in AGB models if we adopt a mixing length of 1.2 pressure scale height ($\\alpha = 1.2$). However, the ef...
Chakrabarti, Sandip K; Debnath, Dipak
2015-01-01
It has long been proposed that low frequency QPOs in stellar mass black holes or their equivalents in super massive black holes are results of resonances between infall and cooling time scales. We explicitly compute these two time scales in a generic situation to show that resonances are easily achieved. During an outburst of a transient black hole candidate (BHC), the accretion rate of the Keplerian disk as well as the geometry of the Comptonizing cloud change very rapidly. During some period, resonance condition between the cooling time scale (predominantly by Comptonization) and the infall time scale of the Comptonizing cloud is roughly satisfied. This leads to low frequency quasi-periodic oscillations (LFQPOs) of the Compton cloud and the consequent oscillation of hard X-rays. In this paper, we explicitly follow the BHC H 1743-322 during its 2010 outburst. We compute Compton cooling time and infall time on several days and show that QPOs take place when these two roughly agree within ~50%, i.e., the reson...
Entangled three-particle states in magnetic field: Periodic correlations and density matrices
Amitabha Chakrabarti; Anirban Chakraborti
2010-04-28
We present a novel study of the time evolutions of entangled states of three spin-1/2 particles in the presence of a constant external magnetic field, which causes the individual spins to precess and leads to remarkable periodicities in the correlations and density matrices. The emerging patterns of periodicity are studied explicitly for different entangled states and in detail for a particular initial configuration of the velocities. Contributions to precession of anomalous magnetic moments are analysed and general results are also obtained. We then introduce an electric field orthogonal to the magnetic field, linking to the preceding case via a suitable Lorentz transformation, and obtain the corresponding Wigner rotations of the spin states. Finally, we point out for the first time that the entangled states corresponding to well-known ones in the study of 3-particle entanglements, may be classified systematically using a particular coupling of three angular momenta.
Dual periodicities in the rotational modulation of Saturn narrowband emissions
Gurnett, Donald A.
Dual periodicities in the rotational modulation of Saturn narrowband emissions S.Y. Ye,1 D. A emissions is examined, restricting the spacecraft location to either the northern or the southern hemisphere of Saturn. It is found that in both hemispheres, the modulation period of 5 kHz narrowband emissions has two
Homogenization of linear spatially periodic electronic Michel Lenczner
Homogenization of linear spatially periodic electronic circuits Michel Lenczner January 20, 2006 Abstract: In this paper we establish a simplified model of general spatially periodic linear electronic is reported. 1 Introduction It is well known that when the size of an analog electronic network increases too
Multivariate periodic wavelet analysis Dirk Langemann, Jurgen Prestin
Prestin, JÃ¼rgen
Multivariate periodic wavelet analysis Dirk Langemann, JÂ¨urgen Prestin University of LÂ¨ubeck, Institute of Mathematics, Wallstr. 40, D-23560 LÂ¨ubeck, Germany Abstract General multivariate periodic are generalized to multivariate shift invariant spaces on non-tensor-product pat- terns. In particular
Saving and Using Encountered Information: Implications for Electronic Periodicals
Marshall, Cathy
Saving and Using Encountered Information: Implications for Electronic Periodicals Catherine C of a focus on electronic publications, we undertook an exploratory study of how people saved and used study participants had examples of materials they had deliberately saved from periodicals, ranging from
Optical characterization of periodically-poled KTiOPO4
Exter, Martin van
Optical characterization of periodically-poled KTiOPO4 W. H. Peeters and M. P. van Exter Huygens-conversion(SPDC) give a direct visualization of the poling quality of a periodically-poled crystal. Identical Maker with small and slowly-varying deformations of the poling structure. Our theoretical model, based on a Fourier
Quantum coherent switch utilizing commensurate nanoelectrode and charge density periodicities
Harrison; Neil (Santa Fe, NM), Singleton; John (Los Alamos, NM), Migliori; Albert (Santa Fe, NM)
2008-08-05
A quantum coherent switch having a substrate formed from a density wave (DW) material capable of having a periodic electron density modulation or spin density modulation, a dielectric layer formed onto a surface of the substrate that is orthogonal to an intrinsic wave vector of the DW material; and structure for applying an external spatially periodic electrostatic potential over the dielectric layer.
Time, Clocks and the Speed of Light Vasco Guerra
Guerra, Vasco
Time, Clocks and the Speed of Light Vasco Guerra and Rodrigo de Abreu Departamento de Física are a direct consequence of the fundamental notions of time and clocks. They can be obtained without any time, independently of the periodic physical phenomena they are built upon and of the machinery
Unstable periodic orbits in a chaotic meandering jet flow
Uleysky, M Yu; Prants, S V; 10.1088/1751-8113/41/21/215102
2012-01-01
We study the origin and bifurcations of typical classes of unstable periodic orbits in a jet flow that was introduced before as a kinematic model of chaotic advection, transport and mixing of passive scalars in meandering oceanic and atmospheric currents. A method to detect and locate the unstable periodic orbits and classify them by the origin and bifurcations is developed. We consider in detail period-1 and period-4 orbits playing an important role in chaotic advection. We introduce five classes of period-4 orbits: western and eastern ballistic ones, whose origin is associated with ballistic resonances of the fourth order, rotational ones, associated with rotational resonances of the second and fourth orders, and rotational-ballistic ones associated with a rotational-ballistic resonance. It is a new kind of nonlinear resonances that may occur in chaotic flow with jets and/or circulation cells. Varying the perturbation amplitude, we track out the origin and bifurcations of the orbits for each class.
Unstable periodic orbits in a chaotic meandering jet flow
M. Yu. Uleysky; M. V. Budyansky; S. V. Prants
2007-12-25
We study the origin and bifurcations of typical classes of unstable periodic orbits in a jet flow that was introduced before as a kinematic model of chaotic advection, transport and mixing of passive scalars in meandering oceanic and atmospheric currents. A method to detect and locate the unstable periodic orbits and classify them by the origin and bifurcations is developed. We consider in detail period-1 and period-4 orbits playing an important role in chaotic advection. We introduce five classes of period-4 orbits: western and eastern ballistic ones, whose origin is associated with ballistic resonances of the fourth order, rotational ones, associated with rotational resonances of the second and fourth orders, and rotational-ballistic ones associated with a rotational-ballistic resonance. It is a new kind of nonlinear resonances that may occur in chaotic flow with jets and/or circulation cells. Varying the perturbation amplitude, we track out the origin and bifurcations of the orbits for each class.
Stevens, Fred J. (Naperville, IL)
1992-01-01
A novel method of electric field flow fractionation for separating solute molecules from a carrier solution is disclosed. The method of the invention utilizes an electric field that is periodically reversed in polarity, in a time-dependent, wave-like manner. The parameters of the waveform, including amplitude, frequency and wave shape may be varied to optimize separation of solute species. The waveform may further include discontinuities to enhance separation.
Occurrence and Stability of Glaciations in Geologic Time
Zhuang, Kelin
2011-10-21
Earth is characterized by episodes of glaciations and periods of minimal or no ice through geologic time. Using the linear energy balance model (EBM), nonlinear EBM with empirical ice sheet schemes, the general circulation model coupled with an ice...
The continuous period search method and its application to the young solar analogue HD 116956
Lehtinen, J; Hackman, T; Henry, P Kajatkari G W
2010-01-01
Aims: We formulate an improved time series analysis method for the analysis of photometry of active stars. This new Continuous Period Search (CPS) method is applied to 12 years of V band photometry of the young solar analogue HD 116956 (NQ UMa). Methods: The new method is developed from the previous Three Stage Period Analysis (TSPA) method. Our improvements are the use of a sliding window in choosing the modelled datasets, a criterion applied to select the best model for each dataset and the computation of the time scale of change of the light curve. We test the performance of CPS with simulated and real data. Results: The CPS has a much improved time resolution which allows us to better investigate fast evolution of stellar light curves. We can also separate between the cases when the data is best described by periodic (i.e. rotational modulation of brightness) and aperiodic (e.g. constant brightness) models. We find, however, that the performance of the CPS has certain limitations. It does not determine th...
Steady-State Electrical Conduction in the Periodic Lorentz Gas
N. I. Chernov; G. L. Eyink; J. L. Lebowitz; Ya. G. Sinai
1993-02-08
We study nonequilibrium steady states in the Lorentz gas of periodic scatterers when an external field is applied and the particle kinetic energy is held fixed by a ``thermostat'' constructed according to Gauss' principle of least constraint (a model problem previously studied numerically by Moran and Hoover). The resulting dynamics is reversible and deterministic, but does not preserve Liouville measure. For a sufficiently small field, we prove the following results: (1) existence of a unique stationary, ergodic measure obtained by forward evolution of initial absolutely continuous distributions, for which the Pesin entropy formula and Young's expression for the fractal dimension are valid; (2) exact identity of the steady-state thermodyamic entropy production, the asymptotic decay of the Gibbs entropy for the time-evolved distribution, and minus the sum of the Lyapunov exponents; (3) an explicit expression for the full nonlinear current response (Kawasaki formula); and (4) validity of linear response theory and Ohm's transport law, including the Einstein relation between conductivity and diffusion matrices. Results (2) and (4) yield also a direct relation between Lyapunov exponents and zero-field transport (=diffusion) coefficients. Although we restrict ourselves here to dimension $d=2,$ the results carry over to higher dimensions and to some other physical situations: e.g. with additional external magnetic fields. The proofs use a well-developed theory of small perturbations of hyperbolic dynamical systems and the method of Markov sieves, an approximation of Markov partitions. In our context we discuss also the van Kampen objection to linear response theory, which, we point out, overlooks the ``structural stability'' of strongly hyperbolic flows.
Time Crystals from Minimum Time Uncertainty
Mir Faizal; Mohammed M. Khalil; Saurya Das
2014-12-29
Motivated by the Generalized Uncertainty Principle, covariance, and a minimum measurable time, we propose a deformation of the Heisenberg algebra, and show that this leads to corrections to all quantum mechanical systems. We also demonstrate that such a deformation implies a discrete spectrum for time. In other words, time behaves like a crystal.
Enhanced entrainability of genetic oscillators by period mismatch
Yoshihiko Hasegawa; Masanori Arita
2013-01-12
Biological oscillators coordinate individual cellular components so that they function coherently and collectively. They are typically composed of multiple feedback loops, and period mismatch is unavoidable in biological implementations. We investigated the advantageous effect of this period mismatch in terms of a synchronization response to external stimuli. Specifically, we considered two fundamental models of genetic circuits: smooth- and relaxation oscillators. Using phase reduction and Floquet multipliers, we numerically analyzed their entrainability under different coupling strengths and period ratios. We found that a period mismatch induces better entrainment in both types of oscillator; the enhancement occurs in the vicinity of the bifurcation on their limit cycles. In the smooth oscillator, the optimal period ratio for the enhancement coincides with the experimentally observed ratio, which suggests biological exploitation of the period mismatch. Although the origin of multiple feedback loops is often explained as a passive mechanism to ensure robustness against perturbation, we study the active benefits of the period mismatch, which include increasing the efficiency of the genetic oscillators. Our findings show a qualitatively different perspective for both the inherent advantages of multiple loops and their essentiality.
Development of Seismic Isolation Systems Using Periodic Materials
Yan, Yiqun; Mo, Yi-Lung; Menq, Farn-Yuh; Stokoe, II, Kenneth H.; Perkins, Judy; Tang, Yu
2014-12-10
Advanced fast nuclear power plants and small modular fast reactors are composed of thin-walled structures such as pipes; as a result, they do not have sufficient inherent strength to resist seismic loads. Seismic isolation, therefore, is an effective solution for mitigating earthquake hazards for these types of structures. Base isolation, on which numerous studies have been conducted, is a well-defined structure protection system against earthquakes. In conventional isolators, such as high-damping rubber bearings, lead-rubber bearings, and friction pendulum bearings, large relative displacements occur between upper structures and foundations. Only isolation in a horizontal direction is provided; these features are not desirable for the piping systems. The concept of periodic materials, based on the theory of solid-state physics, can be applied to earthquake engineering. The periodic material is a material that possesses distinct characteristics that prevent waves with certain frequencies from being transmitted through it; therefore, this material can be used in structural foundations to block unwanted seismic waves with certain frequencies. The frequency band of periodic material that can filter out waves is called the band gap, and the structural foundation made of periodic material is referred to as the periodic foundation. The design of a nuclear power plant, therefore, can be unified around the desirable feature of a periodic foundation, while the continuous maintenance of the structure is not needed. In this research project, three different types of periodic foundations were studied: one-dimensional, two-dimensional, and three-dimensional. The basic theories of periodic foundations are introduced first to find the band gaps; then the finite element methods are used, to perform parametric analysis, and obtain attenuation zones; finally, experimental programs are conducted, and the test data are analyzed to verify the theory. This procedure shows that the periodic foundation is a promising and effective way to mitigate structural damage caused by earthquake excitation.
Fourier Analysis and Autocorrelation Function Applied to Periodical Nanostructures
Rockett, Angus
Fourier Analysis and Autocorrelation Function Applied to Periodical Nanostructures E. Cruz Microscopy (AFM) Image Fast Fourier Transformation Autocorrelation Function(AC) Angular Distribution] Fourier Analysis: analytical and geometrical aspects, Bray William O ed. New York: Marcel Dekker, 1994
Period tripling accumulation point for complexified Henon map
O. B. Isaeva; S. P. Kuznetsov
2005-09-06
Accumulation point of period-tripling bifurcations for complexified Henon map is found. Universal scaling properties of parameter space and Fourier spectrum intrinsic to this critical point is demonstrated.
Single-valued periods and multiple zeta values
Francis Brown
2013-09-20
The values at 1 of single-valued multiple polylogarithms span a certain subalgebra of multiple zeta values. In this paper, the properties of this algebra are studied from the point of view of motivic periods.
Generalized Cost Function Based Forecasting for Periodically Measured Nonstationary Traffic
Zeng, Yong - Department of Mathematics and Statistics, University of Missouri
1 Generalized Cost Function Based Forecasting for Periodically Measured Nonstationary Traffic true value. However, such a forecast- ing function is not directly applicable for applications potentially result in insufficient allocation of bandwidth leading to short term data loss. To facilitate
Neutron-Scattering Evidence for a Periodically Modulated Superconducti...
Office of Scientific and Technical Information (OSTI)
Neutron-Scattering Evidence for a Periodically Modulated Superconducting Phase in the Underdoped Cuprate La1.905Ba0.095CuO4 Citation Details In-Document Search Title:...
Dispersion extraction with near-field measurements in periodic waveguides
, R. D. Meade, and J. N. Winn, Photonic Crystals: Molding the Flow of Light (Princeton University. Joannopoulos, "Guided and defect modes in periodic dielectric wave-guides," J. Opt. Soc. Am. B 12, 1267
Linear Scaling Electronic Structure Methods with Periodic Boundary Conditions
Gustavo E. Scuseria
2008-02-08
The methodological development and computational implementation of linear scaling quantum chemistry methods for the accurate calculation of electronic structure and properties of periodic systems (solids, surfaces, and polymers) and their application to chemical problems of DOE relevance.
No more periods? Oral contraception and menstrual suppression
Gunson, Dr Jessie
Oral contraception, or ‘The Pill’, is widely used by women to control how often they have a period. In many countries using oral contraception in this way has remained unofficial practice. However, in 2003 the first FDA ...
Transport and Fractionation in Periodic Potential-Energy Landscapes
Kosta Ladavac; Matthew Pelton; David G. Grier
2004-04-09
Objects driven through periodically modulated potential-energy landscapes in two dimensions can become locked in to symmetry-selected directions that are independent of the driving force's orientation. We investigate this problem in the overdamped limit, and demonstrate that the crossover from free-flowing to locked-in transport can depend exponentially on an object's size, with this exceptional selectivity emerging from the periodicity of the environment.
Modal Approach to Casimir Forces in Periodic Structures
P. S. Davids; F. Intravaia; F. S. S. Rosa; D. A. R. Dalvit
2010-08-20
We present a modal approach to calculate finite temperature Casimir interactions between two periodically modulated surfaces. The scattering formula is used and the reflection matrices of the patterned surfaces are calculated decomposing the electromagnetic field into the natural modes of the structures. The Casimir force gradient from a deeply etched silicon grating is evaluated using the modal approach and compared to experiment for validation. The Casimir force from a two dimensional periodic structure is computed and deviations from the proximity force approximation examined.
Experimental continuation of periodic orbits through a fold
J. Sieber; A. Gonzalez-Buelga; S. A. Neild; D. J. Wagg; B. Krauskopf
2008-06-12
We present a continuation method that enables one to track or continue branches of periodic orbits directly in an experiment when a parameter is changed. A control-based setup in combination with Newton iterations ensures that the periodic orbit can be continued even when it is unstable. This is demonstrated with the continuation of initially stable rotations of a vertically forced pendulum experiment through a fold bifurcation to find the unstable part of the branch.
Periodic equivalence ratio modulation method and apparatus for controlling combustion instability
Richards, George A. (Morgantown, WV); Janus, Michael C. (Baltimore, MD); Griffith, Richard A. (Morgantown, WV)
2000-01-01
The periodic equivalence ratio modulation (PERM) method and apparatus significantly reduces and/or eliminates unstable conditions within a combustion chamber. The method involves modulating the equivalence ratio for the combustion device, such that the combustion device periodically operates outside of an identified unstable oscillation region. The equivalence ratio is modulated between preselected reference points, according to the shape of the oscillation region and operating parameters of the system. Preferably, the equivalence ratio is modulated from a first stable condition to a second stable condition, and, alternatively, the equivalence ratio is modulated from a stable condition to an unstable condition. The method is further applicable to multi-nozzle combustor designs, whereby individual nozzles are alternately modulated from stable to unstable conditions. Periodic equivalence ratio modulation (PERM) is accomplished by active control involving periodic, low frequency fuel modulation, whereby low frequency fuel pulses are injected into the main fuel delivery. Importantly, the fuel pulses are injected at a rate so as not to affect the desired time-average equivalence ratio for the combustion device.
Periodic equivalence ratio modulation method and apparatus for controlling combustion instability
Richards, G.A.; Janus, M.C.; Griffith, R.A.
2000-05-09
The periodic equivalence ratio modulation (PERM) method and apparatus significantly reduces and/or eliminates unstable conditions within a combustion chamber. The method involves modulating the equivalence ratio for the combustion device, such that the combustion device periodically operates outside of an identified unstable oscillation region. The equivalence ratio is modulated between preselected reference points, according to the shape of the oscillation region and operating parameters of the system. Preferably, the equivalence ratio is modulated from a first stable condition to a second stable condition, and, alternatively, the equivalence ratio is modulated from a stable condition to an unstable condition. The method is further applicable to multi-nozzle combustor designs, whereby individual nozzles are alternately modulated from stable to unstable conditions. Periodic equivalence ratio modulation (PERM) is accomplished by active control involving periodic, low frequency fuel modulation, whereby low frequency fuel pulses are injected into the main fuel delivery. Importantly, the fuel pulses are injected at a rate so as not to affect the desired time-average equivalence ratio for the combustion device.
Space time and the passage of time
George F. R. Ellis; Rituparno Goswami
2012-08-26
This paper examines the various arguments that have been put forward suggesting either that time does not exist, or that it exists but its flow is not real. I argue that (i) time both exists and flows; (ii) an Evolving Block Universe (`EBU') model of spacetime adequately captures this feature, emphasizing the key differences between the past, present, and future; (iii) the associated surfaces of constant time are uniquely geometrically and physically determined in any realistic spacetime model based in General Relativity Theory; (iv) such a model is needed in order to capture the essential aspects of what is happening in circumstances where initial data does not uniquely determine the evolution of spacetime structure because quantum uncertainty plays a key role in that development. Assuming that the functioning of the mind is based in the physical brain, evidence from the way that the mind apprehends the flow of time prefers this evolving time model over those where there is no flow of time.
White, Lynn
2000-06-27
People view time in different ways, but we all could do a better job of managing our time. This publication explains three different time management tools: the 24-hour time log and chart; a self-assessment of thinking styles and time management...
Kato, Taichi; Dubovsky, Pavol A; Kudzej, Igor; Monard, Berto; Miller, Ian; Itoh, Hiroshi; Kiyota, Seiichiro; Masumoto, Kazunari; Fukushima, Daiki; Kinoshita, Hiroki; Maeda, Kazuki; Mikami, Jyunya; Matsuda, Risa; Kojiguchi, Naoto; Kawabata, Miho; Takenaka, Megumi; Matsumoto, Katsura; de Miguel, Enrique; Maeda, Yutaka; Ohshima, Tomohito; Isogai, Keisuke; Pickard, Roger D; Henden, Arne; Kafka, Stella; Akazawa, Hidehiko; Otani, Noritoshi; Ishibashi, Sakiko; Ogi, Minako; Tanabe, Kenji; Imamura, Kazuyoshi; Stein, William; Kasai, Kiyoshi; Vanmunster, Tonny; Starr, Peter; Pavlenko, Elena P; Antonyuk, Oksana I; Antonyuk, Kirill A; Sosnovskij, Aleksei A; Pit, Nikolaj V; Babina, Julia V; Sklyanov, Aleksandr; Novak, Rudolf; Oksanen, Arto; Dvorak, Shawn; Michel, Raul; Masi, Gianluca; Littlefield, Colin; Ulowetz, Joseph; Shugarov, Sergey Yu; Golysheva, Polina Yu; Chochol, Drahomir; Krushevska, Viktoriia; Ruiz, Javier; Tordai, Tamas; Morelle, Etienne; Sabo, Richard; Maehara, Hiroyuki; Richmond, Michael; Katysheva, Natalia; Hirosawa, Kenji; Goff, William N; Dubois, Franky; Logie, Ludwig; Rau, Steve; Voloshina, Irina B; Andreev, Maksim V; Shiokawa, Kazuhiko; Neustroev, Vitaly V; Sjoberg, George; Zharikov, Sergey; James, Nick; Bolt, Greg; Crawford, Tim; Buczynski, Denis; Cook, Lewis M; Kochanek, Christopher S; Shappee, Benjamin; Stanek, Krzysztof Z; Prieto, Jose L; Denisenko, Denis; Nishimura, Hideo; Mukai, Masaru; Kaneko, Shizuo; Ueda, Seiji; Stubbings, Rod; Moriyama, Masayuki; Schmeer, Patrick; Muyllaert, Eddy; Shears, Jeremy; Modic, Robert J; Paxson, Kevin B
2015-01-01
Continuing the project described by Kato et al. (2009, arXiv:0905.1757), we collected times of superhump maxima for 102 SU UMa-type dwarf novae observed mainly during the 2014-2015 season and characterized these objects. Our project has greatly improved the statistics of the distribution of orbital periods, which is a good approximation of the distribution of cataclysmic variables at the terminal evolutionary stage, and confirmed the presence of a period minimum at a period of 0.053 d and a period spike just above this period. The number density monotonically decreased toward the longer period and there was no strong indication of a period gap. We detected possible negative superhumps in Z Cha. It is possible that normal outbursts are also suppressed by the presence of a disk tilt in this system. There was no indication of enhanced orbital humps just preceding the superoutburst, and this result favors the thermal-tidal disk instability as the origin of superoutbursts. We detected superhumps in three AM CVn-ty...
Periodicities in the X-ray emission from the solar corona
Chowdhury, Partha; Jain, Rajmal; Awasthi, Arun K. E-mail: parthares@gmail.com E-mail: awasthi@prl.res.in
2013-11-20
We have studied the time series of full disk integrated soft and hard X-ray emission from the solar corona during 2004 January to 2008 December, covering the entire descending phase of solar cycle 23 from a global point of view. We employ the daily X-ray index derived from 1 s cadence X-ray observations from the Si and CZT detectors of the 'Solar X-ray Spectrometer' mission in seven different energy bands ranging between 6 and 56 keV. X-ray data in the energy bands 6-7, 7-10, 10-20, and 4-25 keV from the Si detector are considered, while 10-20, 20-30, and 30-56 keV high energy observations are taken from the CZT detector. The daily time series is subjected to power spectrum analysis after appropriate correction for noise. The Lomb-Scargle periodogram technique has shown prominent periods of ?13.5 days, ?27 days, and a near-Rieger period of ?181 days and ?1.24 yr in all energy bands. In addition to this, other periods like ?31, ?48, ?57, ?76, ?96, ?130, ?227, and ?303 days are also detected in different energy bands. We discuss our results in light of previous observations and existing numerical models.
A search for periodicities from a ULX in the LINER galaxy NGC 4736
Avdan, H; Akyuz, A; Balman, S
2014-01-01
We report our findings on a new quasi-periodic oscillation (QPO) and a long period from the ultraluminous X-ray source (ULX) X-2 in nearby galaxy NGC 4736 based on the Chandra and XMM-Newton archival data. To examine the timing properties, power density spectra of the source have been obtained using Fast Fourier Transform. Also the spectral parameters of the source have been calculated by obtaining and fitting the energy spectra. Power density spectrum of this source reveals a QPO peak at $0.73_{-0.14}^{+0.16}$ mHz with an fractional rms variability of 16% using the Chandra data (in the year 2000-lower state of the source). The XMM-Newton data analysis indicates a peak at $0.53_{-0.35}^{+0.09}$ mHz with a fractional rms variation of 5% (in the year 2006-higher state of the source). These recovered QPOs overlap within errors and may be the same oscillation. In addition, we detect a long periodicity or a QPO in the Chandra data of about $(5.2\\pm2.0)\\times10^{-5}$ Hz ($\\sim$ 5.4 hrs) over 3 $\\sigma$ confidence l...
Tracking multiple generation and suppression of secondary electrons on periodic triangular surface
Li, S.; Wang, J. G.; Zhu, M.; Peng, J. C.; Xie, J. L.; Wu, X. L.; Guo, L. T.; Chang, C.; Xiong, Z. F.; Department of Engineering Physics, Tsinghua University, Beijing 10084
2013-12-15
To research the dynamic course of multipactor suppression on the periodically patterned surface, tens of electron collision processes are tracked by numerical calculation. The influences of microwave frequency, amplitude of RF electric field, slope angle, the local field enhancement, and the tilted incident electric field on the multipactor suppression are studied by tracking multi-generation electrons' trajectories, hopping and flight time, collision energy, and secondary emission yield. Meanwhile, the dynamic processes of secondary electrons on the periodic surface are analyzed by particle-in-cell (PIC) simulation. The PIC results are consistent with the analytical results in which the electrons fly reciprocatingly between the slopes and impact on the slopes; the methods of increasing the slope angle, enlarging the RF field, and lowering the frequency in a certain range are helpful to enhance the multipactor suppression steadily and persistently.
The Design of a Synthesis Tool for Interrupt-based Real Time Embedded Software
Hsiung, Pao-Ann
to accomplish some dedicated set of periodic tasks within real time deadlines. Some examples include avionics Thermometer with Microcontroller (DTM) and a Real-time Stepping Motor Control (RSMC) to demonstrate
Sensitive response of a model of symbiotic ecosystem to seasonal periodic drive
Rekker, A.; Lumi, N.; Mankin, R.
2014-11-12
A symbiotic ecosysytem (metapopulation) is studied by means of the stochastic Lotka-Volterra model with generalized Verhulst self-regulation. The effect of variable environment on the carrying capacities of populations is taken into account as an asymmetric dichotomous noise and as a deterministic periodic stimulus. In the framework of the mean-field theory an explicit self-consistency equation for the system in the long-time limit is presented. Also, expressions for the probability distribution and for the moments of the population size are found. In certain cases the mean population size exhibits large oscillations in time, even if the amplitude of the seasonal environmental drive is small. Particularly, it is shown that the occurrence of large oscillations of the mean population size can be controlled by noise parameters (such as amplitude and correlation time) and by the coupling strength of the symbiotic interaction between species.
Qin, Xiao
Scheduling of Periodic Packets in Energy-Aware Wireless Networks Xiao Qin , Mohammed Alghamdi, Mais. Abstract Existing packets scheduling algorithms designed for energy-efficient wireless networks ignore in wireless networks subject to both timing and energy constraints. We propose a necessary and sufficient
On Time. 6b: Quantum Mechanical Time
C. K. Raju
2008-08-09
The existence of small amounts of advanced radiation, or a tilt in the arrow of time, makes the basic equations of physics mixed-type functional differential equations. The novel features of such equations point to a microphysical structure of time. This corresponds to a change of logic at the microphysical level. We show that the resulting logic is a quantum logic. This provides a natural and rigorous explanation of quantum interference. This structured-time interpretation of quantum mechanics is briefly compared with various other interpretations of q.m.
1D periodic potentials with gaps vanishing at k=0
O. Zagordi; A. Michelangeli
2008-10-13
Appearance of energy bands and gaps in the dispersion relations of a periodic potential is a standard feature of Quantum Mechanics. We investigate the class of one-dimensional periodic potentials for which all gaps vanish at the center of the Brillouin zone. We characterize them through a necessary and sufficient condition. Potentials of the form we focus on arise in different fields of Physics, from supersymmetric Quantum Mechanics, to Korteweg-de Vries equation theory and classical diffusion problems. The O.D.E. counterpart to this problem is the characterisation of periodic potentials for which coexistence occur of linearly independent solutions of the corresponding Schroedinger equation (Hill's equation). This result is placed in perspective of the previous related results available in the literature.
National Weatherization Assistance Program Characterization Describing the Recovery Act Period
Tonn, Bruce Edward; Rose, Erin M.; Hawkins, Beth A.
2015-10-01
This report characterizes the U.S. Department of Energy s Weatherization Assistance Program (WAP) during the American Recovery and Reinvestment Act of 2009 (Recovery Act) period. This research was one component of the Recovery Act evaluation of WAP. The report presents the results of surveys administered to Grantees (i.e., state weatherization offices) and Subgrantees (i.e., local weatherization agencies). The report also documents the ramp up and ramp down of weatherization production and direct employment during the Recovery Act period and other challenges faced by the Grantees and Subgrantees during this period. Program operations during the Recovery Act (Program Year 2010) are compared to operations during the year previous to the Recovery Act (Program Year 2008).
Lyapunov functions for periodic matrix-valued Jacobi operators
Evgeny Korotyaev; Anton Kutsenko
2007-01-16
We consider periodic matrix-valued Jacobi operators. The spectrum of this operator is absolutely continuous and consists of intervals separated by gaps. We define the Lyapunov function, which is analytic on an associated Riemann surface. On each sheet the Lyapunov function has the standard properties of the Lyapunov function for the scalar case. We show that this function has (real or complex) branch points, which we call resonances. We prove that there exist two types of gaps: i) stable gaps, i.e., the endpoints are periodic and anti-periodic eigenvalues, ii) unstable (resonance) gaps, i.e., the endpoints are resonances (real branch points). We show that some spectral data determine the spectrum (counting multiplicity) of the Jacobi operator.
Periodic Discrete Energy for Long-Range Potentials
D. P. Hardin; E. B. Saff; Brian Simanek
2014-12-11
We consider periodic energy problems in Euclidean space with a special emphasis on long-range potentials that cannot be defined through the usual infinite sum. One of our main results builds on more recent developments of Ewald summation to define the periodic energy corresponding to a large class of long-range potentials. Two particularly interesting examples are the logarithmic potential and the Riesz potential when the Riesz parameter is smaller than the dimension of the space. For these examples, we use analytic continuation methods to provide concise formulas for the periodic kernel in terms of the Epstein Hurwitz Zeta function. We apply our energy definition to deduce several properties of the minimal energy including the asymptotic order of growth and the distribution of points in energy minimizing configurations as the number of points becomes large. We conclude with some detailed calculations in the case of one dimension, which shows the utility of this approach.
Point Vortices: Finding Periodic Orbits and their Topological Classification
Spencer A. Smith
2015-10-22
The motion of point vortices constitutes an especially simple class of solutions to Euler's equation for two dimensional, inviscid, incompressible, and irrotational fluids. In addition to their intrinsic mathematical importance, these solutions are also physically relevant. Rotating superfluid helium can support rectilinear quantized line vortices, which in certain regimes are accurately modeled by point vortices. Depending on the number of vortices, it is possible to have either regular integrable motion or chaotic motion. Thus, the point vortex model is one of the simplest and most tractable fluid models which exhibits some of the attributes of weak turbulence. The primary aim of this work is to find and classify periodic orbits, a special class of solutions to the point vortex problem. To achieve this goal, we introduce a number of algorithms: Lie transforms which ensure that the equations of motion are accurately solved; constrained optimization which reduces close return orbits to true periodic orbits; object-oriented representations of the braid group which allow for the topological comparison of periodic orbits. By applying these ideas, we accumulate a large data set of periodic orbits and their associated attributes. To render this set tractable, we introduce a topological classification scheme based on a natural decomposition of mapping classes. Finally, we consider some of the intriguing patterns which emerge in the distribution of periodic orbits in phase space. Perhaps the most enduring theme which arises from this investigation is the interplay between topology and geometry. The topological properties of a periodic orbit will often force it to have certain geometric properties.
Periodic homogenization and material symmetry in linear elasticity
Mariya Ptashnyk; Brian Seguin
2015-05-07
Here homogenization theory is used to establish a connection between the symmetries of a periodic elastic structure associated with the microscopic properties of an elastic material and the material symmetries of the effective, macroscopic elasticity tensor. Previous results of this type exist but here more general symmetries on the microscale are considered. Using an explicit example, we show that it is possible for a material to be fully anisotropic on the microscale and yet have a nontrivial material symmetry group on the macroscale. Another example demonstrates that not all material symmetries of the macroscopic elastic tensor are generated by symmetries of the periodic elastic structure.
Self-organized periodicity of protein clusters in growing bacteria
Hui Wang; Ned S. Wingreen; Ranjan Mukhopadhyay
2008-08-06
Chemotaxis receptors in E. coli form clusters at the cell poles and also laterally along the cell body, and this clustering plays an important role in signal transduction. Recently, experiments using flourrescence imaging have shown that, during cell growth, lateral clusters form at positions approximately periodically spaced along the cell body. In this paper, we demonstrate within a lattice model that such spatial organization could arise spontaneously from a stochastic nucleation mechanism. The same mechanism may explain the recent observation of periodic aggregates of misfolded proteins in E. coli.
Periodic Photometric Variability in the Becklin-Neugebauer Object
Lynne A. Hillenbrand; John M. Carpenter; M. F. Skrutskie
2000-10-24
The Becklin-Neugebauer (BN) object in the Orion Nebula Cluster (ONC) is a well-studied optically invisible, infrared-bright young stellar object, thought to be an intermediate-mass protostar. We report here that BN exhibited nearly-sinusoidal periodic variability at the near-infrared H- and Ks-bands during a one month observing campaign in 2000 March/April. The period was 8.28 days and the peak-to-peak amplitude ~0.2 mag. Plausible mechanisms for producing the observed variability characteristics are explored.
Period doubling, information entropy, and estimates for Feigenbaum's constants
Reginald D. Smith
2013-08-03
The relationship between period doubling bifurcations and Feigenbaum's constants has been studied for nearly 40 years and this relationship has helped uncover many fundamental aspects of universal scaling across multiple nonlinear dynamical systems. This paper will combine information entropy with symbolic dynamics to demonstrate how period doubling can be defined using these tools alone. In addition, the technique allows us to uncover some unexpected, simple estimates for Feigenbaum's constants which relate them to log 2 and the golden ratio, phi, as well as to each other.
Proton aurora related to intervals of pulsations of diminishing periods
California at Berkeley, University of
Proton aurora related to intervals of pulsations of diminishing periods A. G. Yahnin,1 T. A are generated because of a cyclotron instability of the anisotropic distribution of ring current ions. Proton precipitation produced by the cyclotron instability can be responsible for proton aurora. Indeed
Emergence of spike correlations in periodically forced excitable systems
Jose A. Reinoso; M. C. Torrent; Cristina Masoller
2015-10-30
In sensory neurons the presence of noise can facilitate the detection of weak information-carrying signals, which are encoded and transmitted via correlated sequences of spikes. Here we investigate relative temporal order in spike sequences induced by a subthreshold periodic input, in the presence of white Gaussian noise. To simulate the spikes, we use the FitzHugh-Nagumo model, and to investigate the output sequence of inter-spike intervals (ISIs), we use the symbolic method of ordinal analysis. We find different types of relative temporal order, in the form of preferred ordinal patterns which depend on both, the strength of the noise and the period of the input signal. We also demonstrate a resonance-like behavior, as certain periods and noise levels enhance temporal ordering in the ISI sequence, maximizing the probability of the preferred patterns. Our findings could be relevant for understanding the mechanisms underlying temporal coding, by which single sensory neurons represent in spike sequences the information about weak periodic stimuli.
Periodic bedrock ridges on Mars David R. Montgomery,1
Montgomery, David R.
Periodic bedrock ridges on Mars David R. Montgomery,1 Joshua L. Bandfield,1 and Scott K. Becker1 to be widespread [Carr, 1981; Greeley et al., 1992; Malin and Edgett, 2001]. Although wind-streamlined yardangs interpreted as sedimentary forms [McCauley et al., 1972; Cutts and Smith, 1973; Carr, 1981; Greeley et al
Periodic fluctuations in deep water formation due to sea ice
Raj Saha
2015-02-21
During the last ice age several quasi-periodic abrupt warming events took place. Known as Dansgaard-Oeschger (DO) events their effects were felt globally, although the North Atlantic experienced the largest temperature anomalies. Paleoclimate data shows that the fluctuations often occurred right after massive glacial meltwater releases in the North Atlantic and in bursts of three or four with progressively decreasing strengths. In this study a simple dynamical model of an overturning circulation and sea ice is developed with the goal of understanding the fundamental mechanisms that could have caused the DO events. Interaction between sea ice and the overturning circulation in the model produces self-sustained oscillations. Analysis and numerical experiments reveal that the insulating effect of sea ice causes the ocean to periodically vent out accumulated heat in the deep ocean into the atmosphere. Subjecting the model to idealized freshwater forcing mimicking Heinrich events causes modulation of the natural periodicity and produces burst patterns very similar to what is observed in temperature proxy data. Numerical experiments with the model also suggests that the characteristic period of 1,500 years is due to the geometry, or the effective heat capacity, of the ocean that comes under sea ice cover.
Greedy Approaches to Static Stochastic Robust Resource Allocation for Periodic
Maciejewski, Anthony A.
Greedy Approaches to Static Stochastic Robust Resource Allocation for Periodic Sensor Driven@us.ibm.com Abstract-- This research investigates the problem of robust resource allocation for a large class. Such systems are expected to function in an environment replete with uncertainty where the workload is likely
lthough Earth has undergone many periods of significant environmen-
Horton, Tom
A lthough Earth has undergone many periods of significant environmen- tal change, the planet push the Earth system outside the stable environmental state of the Holocene, with consequences occurred naturally and Earth's regu- latory capacity maintained the conditions that enabled human
Temperature-induced marine export production during glacial period
Chikamoto, Megumi O.
Temperature-induced marine export production during glacial period M. O. Chikamoto,1,2 A. Abe October 2012; published 8 November 2012. [1] Proxy records indicate that export production was enhanced at the onset of the last glaciation. We examine how glacial cooling affects marine export production through
Bifurcation and Stability Properties of Periodic Solutions to Two Nonlinear
Fiedler, Bernold
motions of suspension bridges. Though they were able to replicate the phenomena observed on the Tacoma in suspen- sion bridges. We contrast the multiplicity, bifurcation, and stability of periodic solutions-doubling and quadrupling) differs significantly. Keywords: suspension bridge, continuation, bifurcation, stability
Urban Water Demand with Periodic Error Correction David R. Bell
Griffin, Ronald
them. Econometric estimates of residential demand for water abound (Dalhuisen et al. 2003Urban Water Demand with Periodic Error Correction by David R. Bell and Ronald C. Griffin February, Department of Agricultural Economics, Texas A&M University. #12;Abstract Monthly demand for publicly supplied
RIEMANN SURFACES, PLANE ALGEBRAIC CURVES AND THEIR PERIOD MATRICES
numerically the canonical map. Therefore symmetric 1991 Mathematics Subject Classification. 14Q05, 14H55, 14P for computing a representation of a compact Riemann surface as an algebraic plane curve and to compute a numerical approximation for its period matrix. We will describe a program Cars ([3]) that can be used
Marchenko-Ostrovski mappings for periodic Jacobi matrices
Evgeny Korotyaev; Anton Kutsenko
2007-10-15
We consider the 1D periodic Jacobi matrices. The spectrum of this operator is purely absolutely continuous and consists of intervals separated by gaps. We solve the inverse problem (including characterization) in terms of vertical slits on the quasimomentum domain . Furthermore, we obtain a priori two-sided estimates for vertical slits in terms of Jacoby matrices.
Strategic Sourcing Dashboard Reporting Period: January 2010 through December 2011
Minnesota, University of
We have accomplished $10.8 million in annual savings through our Strategic Sourcing efforts over below. Strategic Sourcing continues to have a significant emphasis for Purchasing Services, but savings/Activities/Risks for this Reporting Period Annual savings of over $200,000 was booked in the last quarter in the office and lab supply
NANO EXPRESS Fabrication of Large Area Periodic Nanostructures Using
Mohseni, Hooman
, such as photonic band-gap materials, high dense data storage, and photonic devices. We have developed a maskless areas, such as photonic band-gap materials [1], high dense data storage [2], and photonic devices [3NANO EXPRESS Fabrication of Large Area Periodic Nanostructures Using Nanosphere Photolithography
Total Estimated Contract Cost: Contract Option Period: Performance
Office of Environmental Management (EM)
Performance Period Fee Earned FY2000 thru 2008 102,622,325 FY2009 12,259,719 FY2010 35,789,418 FY2011 24,126,240 FY2012 24,995,209 FY2013 6,340,762 FY2014 16,285,867 FY2015...
Rehabilitating space-times with NUTs
Clément, Gérard; Guenouche, Mourad
2015-01-01
We revisit the Taub-NUT solution of the Einstein equations without time periodicity condition, showing that the Misner string is still fully transparent for geodesics. In this case, analytic continuation can be carried out through both horizons leading to a Hausdorff spacetime without a central singularity, and thus geodesically complete. Furthermore, we show that, in spite of the presence of a region containing closed time-like curves, there are no closed causal {\\em geodesics}. Thus, some longstanding obstructions to accept the Taub-NUT solution as physically relevant are removed.
Rehabilitating space-times with NUTs
Gérard Clément; Dmitri Gal'tsov; Mourad Guenouche
2015-08-30
We revisit the Taub-NUT solution of the Einstein equations without time periodicity condition, showing that the Misner string is still fully transparent for geodesics. In this case, analytic continuation can be carried out through both horizons leading to a Hausdorff spacetime without a central singularity, and thus geodesically complete. Furthermore, we show that, in spite of the presence of a region containing closed time-like curves, there are no closed causal {\\em geodesics}. Thus, some longstanding obstructions to accept the Taub-NUT solution as physically relevant are removed.
Yet another time about time - Part I
Plamen L. Simeonov
2015-08-29
This paper presents yet another personal reflection on one the most important concepts in both science and the humanities: time. This elusive notion has been not only bothering philosophers since Plato and Aristotle. It goes throughout human history embracing all analytical and creative (anthropocentric) disciplines. Time has been a central theme in physical and life sciences, philosophy, psychology, music, art and many more. This theme is known with a vast body of knowledge across different theories and categories. What has been explored concerns its nature (rational, irrational, arational), appearances/qualia, degrees, dimensions and scales of conceptualization (internal, external, fractal, discrete, continuous, mechanical, quantum, local, global, etc.). Of particular interest have been parameters of time such as duration ranges, resolutions, modes (present, now, past, future), varieties of tenses (e.g. present perfect, present progressive, etc.) and some intuitive, but also fancy phenomenological characteristics such as arrow, stream, texture, width, depth, density, even scent. Perhaps the most distinct characteristic of this fundamental concept is the absolute time constituting the flow of consciousness according to Husserl, the reflection of pure (human) nature without having the distinction between exo and endo. This essay is a personal reflection upon the meaning of time in modern physics and phenomenological philosophy.
Guenter Nimtz
2009-01-26
How much time does a tunneling wave packet spent in traversing a barrier? Quantum mechanical calculations result in zero time inside a barrier . In the nineties analogous tunneling experiments with microwaves were carried out. The results agreed with quantum mechanical calculations. Electron tunneling time is hard to measure being extremely short and parasitic effects due to the electric charge of electrons may be dominant. However, quite recently the atomic ionization tunneling time has been measured. Experimental data of photonic, phononic, and electronic tunneling time is available now and will be presented. It appears that the tunneling time is a universal property independent of the field in question.
de Ponthiere, Pierre; Fumagalli, F; Hambsch, Franz-Josef; Krajci, Tom; Llapasset, J-M; Menzies, Kenneth; Nobile, Marco; Sabo, Richard
2012-01-01
We present the results of collaborative observations of three RR Lyrae stars (CX Lyr, NU Aur and VY CrB) which have a strong Blazhko effect. This work has been initiated and performed in the framework of the GEOS RR Lyr Survey (Groupe Europ\\'een d'Observations Stellaires). From the measured light curves, we have determined the times and the magnitudes at maximum. The times of maxima have been compared to ephemerides to obtain the (O-C) values and from a period analysis of these (O-C) values, the Blazhko period is derived. The Blazhko periods of NU Aur (114.8 days) and VY CrB (32.3 days) are reported here for the first time and a more accurate period for CX Lyr (68.3 days) has been obtained. The three stars are subject to strong Blazhko effect, but this effect has different characteristics for each of them. When we compare the variations of magnitude at maximum and variations of (O-C) values with respect to the Blazhko phase, these variations are either in phase, in opposition, or even in quadrature.
Homogenizing metamaterials, three times
Didier Felbacq
2012-11-08
The homogenization of a metamaterial made of a collection of scatterers periodically disposed is studied from three different points of view. Specifically tools for multiple scattering theory, functional analysis, differential geometry and optimization are used. Detailed numerical results are given and the connections between the different approaches are enlightened.
EE 511 Solutions to Problem Set 8 1. E[Yt] = E[Xt] cos 2fct. E[Yt] is periodic with period 1/fc.
Bhashyam, Srikrishna
EE 511 Solutions to Problem Set 8 1. E[Yt] = E[Xt] cos 2fct. E[Yt] is periodic with period 1/fc. RY (t, t + ) = E[Xt+ cos 2fc(t + )Xt cos 2fct] = RX() 2 [cos 2fc + cos 2fc(2t + )] RY (t, t + ) is periodic with period 1/(2fc). Therefore, Yt is wide-sense cyclostationary with period 1/fc. E[Zt] = E[Xt]E[cos
Time Asymmetric Quantum Physics
A. Bohm
1999-02-26
Mathematical and phenomenological arguments in favor of asymmetric time evolution of micro-physical states are presented.
Noncommutative Two Time Physics
W. Chagas-Filho
2006-05-10
We present a classical formalism describing two-time physics with Abelian canonical gauge field backgrounds. The formalism can be used as a starting point for the construction of an interacting quantized two-time physics theory in a noncommutative soace-time.
IRC-10443: a multi-periodic SRa variable and the nature of long secondary periods in AGB stars
U. Munari; A. Siviero; P. Ochner; S. Dallaporta; C. Simoncelli
2008-10-08
We obtained BVIc photometry of IRC-10443 on 85 different nights distributed over two years, and in addition low resolution absolute spectro- photometry and high resolution Echelle spectroscopy. Our data show that IRC-10443, which was never studied before in any detail, is a SRa variable, characterized by Delta(B)=1.27, Delta(V)=1.14 and Delta(I)=0.70 mag amplitudes and mean values =13.75, =11.33 and =6.18 mag. Two strong periodicities are simultaneously present: a principal one of 85.5 (+/-0.2) days, and a secondary one of 620 (+/-15) days, both sinusoidal in shape, and with semi-amplitudes Delta(V)=0.41 and 0.20 mag, respectively. IRC-10443 turns out to be a M7III star, with a mean heliocentric radial velocity -28 km/s and reddened by E(B-V)=0.87, a third of which of circumstellar origin. The same 0.5 kpc distance is derived from application of the appropriate period-luminosity relations to both the principal and the secondary periods. The long secondary period causes a sinusoidal variation in color of 0.13 mag semi-amplitude in V-Ic, with IRC-10443 being bluest at maximum and reddest at minimum, and with associated changes in effective temperature and radius of 85 K and 6%, respectively. This behavior of colors argues in favor of a pulsation nature for the still mysterious long secondary periods in AGB stars.
Long-lived periodic revivals of coherence in an interacting Bose-Einstein condensate
Egorov, M.; Ivannikov, V.; Opanchuk, B.; Drummond, P.; Hall, B. V.; Sidorov, A. I. [ARC Centre of Excellence for Quantum-Atom Optics and Centre for Atom Optics and Ultrafast Spectroscopy, Swinburne University of Technology, Melbourne 3122 (Australia); Anderson, R. P. [ARC Centre of Excellence for Quantum-Atom Optics and Centre for Atom Optics and Ultrafast Spectroscopy, Swinburne University of Technology, Melbourne 3122 (Australia); School of Physics, Monash University, Victoria 3800 (Australia)
2011-08-15
We observe the coherence of an interacting two-component Bose-Einstein condensate (BEC) surviving for seconds in a trapped Ramsey interferometer. Mean-field-driven collective oscillations of two components lead to periodic dephasing and rephasing of condensate wave functions with a slow decay of the interference fringe visibility. We apply spin echo synchronous with the self-rephasing of the condensate to reduce the influence of state-dependent atom losses, significantly enhancing the visibility up to 0.75 at the evolution time of 1.5 s. Mean-field theory consistently predicts higher visibility than experimentally observed values. We quantify the effects of classical and quantum noise and infer a coherence time of 2.8 s for a trapped condensate of 5.5x10{sup 4} interacting atoms.
2010-01-01
as: Herr et al. : Air pollution exposure during criticalJ, Bobak M: Ambient air pollution and pregnancy outcomes: aSaxon A, Diaz-Sanchez D: Air pollution and allergy: you are
are derived from the analysis of intra-day (hourly) load records from local substations of the Belgian high by a multi-equation system with autocorrelated resid- uals. Satisfactory results are obtained for a large analysis of the electric load is cur- rently a key research area [1, 2] with important impli- cations
Rate description of FokkerPlanck processes with time-periodic parameters Changho Kim a,b
Lee, EokKyun
mechanical) thermal energy that may accumulate in a single reaction coordinate and finally enable for these three sets of functions and strategies are discussed how to solve them. These methods are illustrated reaction the energy necessary for the activation most often stems from the (classical or even quantum
Mojzsis, Stephen J.
in New Mexico with a sensitive camera. You have discovered a new object in our Solar System, which you us new information about some of the distant bodies in our Solar System. Pre-Requisite Knowledge of a distant star. Snorkzat is in the Kuiper Belt of the Solar System and very little is known about it. You
Winkelmann, Tim, E-mail: tim.winkelmann@med.uni-heidelberg.de; Cee, Rainer; Haberer, Thomas; Naas, Bernd; Peters, Andreas; Schreiner, Jochen [Heidelberger Ionenstrahl-Therapie Centrum (HIT), D -69120 Heidelberg (Germany)] [Heidelberger Ionenstrahl-Therapie Centrum (HIT), D -69120 Heidelberg (Germany)
2014-02-15
The clinical operation at the Heidelberg Ion Beam Therapy Center (HIT) started in November 2009; since then more than 1600 patients have been treated. In a 24/7 operation scheme two 14.5 GHz electron cyclotron resonance ion sources are routinely used to produce protons and carbon ions. The modification of the low energy beam transport line and the integration of a third ion source into the therapy facility will be shown. In the last year we implemented a new extraction system at all three sources to enhance the lifetime of extraction parts and reduce preventive and corrective maintenance. The new four-electrode-design provides electron suppression as well as lower beam emittance. Unwanted beam sputtering effects which typically lead to contamination of the insulator ceramics and subsequent high-voltage break-downs are minimized by the beam guidance of the new extraction system. By this measure the service interval can be increased significantly. As a side effect, the beam emittance can be reduced allowing a less challenging working point for the ion sources without reducing the effective beam performance. This paper gives also an outlook to further enhancements at the HIT ion source testbench.
flux is 1.8x109 photons/s at 30 eV and 6x107 photons/s at 60 eV. The best energy resolution is 120 me weeks access is available. Three weeks are available for EU access, provided through Laserlab Europe. The remaining energy can be used as synchronized pump/probe pulses. Any of the Artemis laser outputs can be used
T. Matolcsi; P. Van
2006-10-23
A four dimensional treatment of nonrelativistic space-time gives a natural frame to deal with objective time derivatives. In this framework some well known objective time derivatives of continuum mechanics appear as Lie-derivatives. Their coordinatized forms depends on the tensorial properties of the relevant physical quantities. We calculate the particular forms of objective time derivatives for scalars, vectors, covectors and different second order tensors from the point of view of a rotating observer. The relation of substantial, material and objective time derivatives is treated.
S. Pireaux
2007-03-23
The LISA mission is a space interferometer aiming at the detection of gravitational waves in the [$10^{-4}$,$10^{-1}$] Hz frequency band. In order to reach the gravitational wave detection level, a Time Delay Interferometry (TDI) method must be applied to get rid of (most of) the laser frequency noise and optical bench noise. This TDI analysis is carried out in terms of the coordinate time corresponding to the Barycentric Coordinate Reference System (BCRS), TCB, whereas the data at each of the three LISA stations is recorded in terms of each station proper time. We provide here the required proper time versus BCRS time transformation. We show that the difference in rate of station proper time versus TCB is of the order of $5 10^{-8}$. The difference between station proper times and TCB exhibits an oscillatory trend with a maximum amplitude of about $10^{-3}$ s.
Curt A. Moyer
2013-05-23
The failure of conventional quantum theory to recognize time as an observable and to admit time operators is addressed. Instead of focusing on the existence of a time operator for a given Hamiltonian, we emphasize the role of the Hamiltonian as the generator of translations in time to construct time states. Taken together, these states constitute what we call a timeline, or quantum history, that is adequate for the representation of any physical state of the system. Such timelines appear to exist even for the semi-bounded and discrete Hamiltonian systems ruled out by Pauli's theorem. However, the step from a timeline to a valid time operator requires additional assumptions that are not always met. Still, this approach illuminates the crucial issue surrounding the construction of time operators, and establishes quantum histories as legitimate alternatives to the familiar coordinate and momentum bases of standard quantum theory.
Parameters of Integral Circulant Graphs and Periodic Quantum Dynamics
Nitin Saxena; Simone Severini; Igor Shparlinski
2007-03-26
The intention of the paper is to move a step towards a classification of network topologies that exhibit periodic quantum dynamics. We show that the evolution of a quantum system, whose hamiltonian is identical to the adjacency matrix of a circulant graph, is periodic if and only if all eigenvalues of the graph are integers (that is, the graph is integral). Motivated by this observation, we focus on relevant properties of integral circulant graphs. Specifically, we bound the number of vertices of integral circulant graphs in terms of their degree, characterize bipartiteness and give exact bounds for their diameter. Additionally, we prove that circulant graphs with odd order do not allow perfect state transfer.
Periodic fluctuations in deep water formation due to sea ice
Saha, Raj
2015-01-01
During the last ice age several quasi-periodic abrupt warming events took place. Known as Dansgaard-Oeschger (DO) events their effects were felt globally, although the North Atlantic experienced the largest temperature anomalies. Paleoclimate data shows that the fluctuations often occurred right after massive glacial meltwater releases in the North Atlantic and in bursts of three or four with progressively decreasing strengths. In this study a simple dynamical model of an overturning circulation and sea ice is developed with the goal of understanding the fundamental mechanisms that could have caused the DO events. Interaction between sea ice and the overturning circulation in the model produces self-sustained oscillations. Analysis and numerical experiments reveal that the insulating effect of sea ice causes the ocean to periodically vent out accumulated heat in the deep ocean into the atmosphere. Subjecting the model to idealized freshwater forcing mimicking Heinrich events causes modulation of the natural p...
Periodic Schrödinger operators with local defects and spectral pollution
Eric Cancès; Virginie Ehrlacher; Yvon Maday
2011-11-16
This article deals with the numerical calculation of eigenvalues of perturbed periodic Schr\\"odinger operators located in spectral gaps. Such operators are encountered in the modeling of the electronic structure of crystals with local defects, and of photonic crystals. The usual finite element Galerkin approximation is known to give rise to spectral pollution. In this article, we give a precise description of the corresponding spurious states. We then prove that the supercell model does not produce spectral pollution. Lastly, we extend results by Lewin and S\\'er\\'e on some no-pollution criteria. In particular, we prove that using approximate spectral projectors enables one to eliminate spectral pollution in a given spectral gap of the reference periodic Sch\\"odinger operator.
Inverse design of periodic metallic slits for extraordinary optical transmission
Deng, Yongbo; Liu, Zhenyu; Wu, Yihui
2016-01-01
The inverse design methodology of periodic metallic slits for extraordinary optical transmission is presented based on the topology optimization method. Several topological configurations of periodic metallic slits with typical subwavelength size are derived with transmission peaks at the prescribed incident wavelengths in the visible light region, where the transmissivity is enhanced by effective excitation of surface-plasmon-polariton at the inlet side of the slit, Fabry-P\\'erot resonance of surface-plasmon-polariton inside the slit and radiation of the electromagnetic energy at the outlet side of the slit. The transmission peaks of the derived metallic configurations are raised along with the red shift of the incident wavelength, because of the reduction of the energy absorption and increase of the propagation distance of surface-plasmon-polariton. And the shift of transmission peak is controlled by prescribing a different incident wavelength in the corresponding topology optimization problem. To reduce th...
Period change and stellar evolution of $\\beta$ Cephei stars
Neilson, Hilding R
2015-01-01
The $\\beta$ Cephei stars represent an important class of massive star pulsators probing the evolution of B-type stars and the transition from main sequence to hydrogen-shell burning evolution. By understanding $\\beta$ Cep stars, we gain insights into the detailed physics of massive star evolution such as rotational mixing, convective core overshooting, magnetic fields and stellar winds, all of which play important roles. Similarly, modeling their pulsation provides additional information into their interior structures. Furthermore, measurements of the rate of change of pulsation period offer a direct measure of $\\beta$ Cephei stellar evolution. In this work, we compute state-of-the-art stellar evolution models assuming different amounts of initial rotation and convective core overshoot and measure theoretical rates of period change for which we compare to rates previously measured for a sample of $\\beta$ Cephei stars. The results of this comparison are mixed. For three stars, the rates are too small to infer ...
Quasi-periodic quantum dot arrays produced by electrochemical synthesis
Bandyopadhyay, S.; Miller, A.E.; Yue, D.F.; Banerjee, G.; Ricker, R.E.; Jones, S.; Eastman, J.A.; Baugher, E.; Chandrasekhar, M.
1994-06-01
We discuss a ``gentle`` electrochemical technique for fabricating quasi-periodic quantum dot arrays. The technique exploits a self-organizing phenomenon to produce quasi-periodic arrangement of dots and provides excellent control over dot size and interdot spacing. Unlike conventional nanolithography, it does not cause radiation damage to the structures during exposure to pattern delineating beams (e-beam, ion-beam or x-ray). Moreover, it does not require harsh processing steps like reactive ion etching, offers a minimum feature size of {approximately}40 {angstrom}, allows the fabrication of structures on nonplanar surfaces (e.g. spherical or cylindrical substrates), is amenable to mass production (millions of wafers can be processed simultaneously) and is potentially orders of magnitude cheaper than conventional nanofabrication. In this paper, we describe our initial results and show the promise of this technique for low-cost and high-yield nanosynthesis.
Period tripling causes rotating spirals in agitated wet granular layers
Kai Huang; Ingo Rehberg
2011-07-07
Pattern formation of a thin layer of vertically agitated wet granular matter is investigated experimentally. Rotating spirals with three arms, which correspond to the kinks between regions with different colliding phases, are the dominating pattern. This preferred number of arms corresponds to period tripling of the agitated granular layer, unlike predominantly subharmonic Faraday crispations in dry granular matter. The chirality of the spatiotemporal pattern corresponds to the rotation direction of the spirals.
Sorting by Periodic Potential Energy Landscapes: Optical Fractionation
Kosta Ladavac; Karen Kasza; David G. Grier
2003-10-16
Viscously damped objects driven through a periodically modulated potential energy landscape can become kinetically locked in to commensurate directions through the landscape, and thus can be deflected away from the driving direction. We demonstrate that the threshold for an object to become kinetically locked in to an array can depend exponentially on its size. When implemented with an array of holographic optical tweezers, this provides the basis for a continuous and continuously optimized sorting technique for mesoscopic objects called ``optical fractionation''.
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Enforcement Policy Statement: Compliance Period for Regional Standards
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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: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum12, 2015 Infographiclighbulbs - high-resolution JPG20,1LLC |Compliance Period for
Non-Foster Circuit Loaded Periodic Structures for Broadband Fast and Slow Wave Propagation
Long, Jiang
2015-01-01
1.1 Periodic Structure, Fast and Slow Wave Propagation . 1.2for a periodic structure. . . . . . . Slow and fast waveA unit cell of a periodic structure . . . . .
Yousef Ghazi-Tabatabai
2012-11-19
While Quantum Gravity remains elusive and Quantum Field Theory retains the interpretational difficulties of Quantum Mechanics, we have introduced an alternate approach to the unification of particles, fields, space and time, suggesting that the concept of matter as space without time provides a framework which unifies matter with spacetime and in which we anticipate the development of complete theories (ideally a single unified theory) describing observed 'particles, charges, fields and forces' solely with the geometry of our matter-space-time universe.
Intrinsic Time Quantum Geometrodynamics
Eyo Eyo Ita III; Chopin Soo; Hoi-Lai Yu
2015-02-06
Quantum Geometrodynamics with intrinsic time development and momentric variables is presented. An underlying SU(3) group structure at each spatial point regulates the theory. The intrinsic time behavior of the theory is analyzed, together with its ground state and primordial quantum fluctuations. Cotton-York potential dominates at early times when the universe was small; the ground state naturally resolves Penrose's Weyl Curvature Hypothesis, and thermodynamic and gravitational `arrows of time' point in the same direction. Ricci scalar potential corresponding to Einstein's General Relativity emerges as a zero-point energy contribution. A new set of fundamental commutation relations without Planck's constant emerges from the unification of Gravitation and Quantum Mechanics.
Orbital and Super-Orbital Periods of 1E 1740.7-2942 and GRS 1758-258
D. M. Smith; W. A. Heindl; J. H. Swank
2002-09-13
Five years of Rossi X-ray Timing Explorer (RXTE) observations of the Galactic black-hole candidates 1E 1740.7-2942 and GRS 1758-258 show a periodic modulation with amplitude 3-4% in each source at 12.73 +/- 0.05 dy and 18.45 +/- 0.10 dy, respectively. We interpret the modulations as orbital, suggesting that the objects have red-giant companions. Combining the RXTE data with earlier data (Zhang, Harmon & Liang 1997) from the Burst and Transient Source Experiment on the Compton Gamma-Ray Observatory, we find a long period or quasi-period of about 600 dy in 1E 1740.7-2942, and a suggestion of a similar 600-dy period in GRS 1758-258. These timescales are longer than any yet found for either precessing systems like Her X-1 and SS 433 or binaries like LMC X-3 and Cyg X-1 with more irregular long periods.
NASA-TM-III642 Design of Inielligent Mesoscale Periodic Array
Asher, Sanford A.
i" /} , NASA-TM-III642 Design of Inielligent Mesoscale Periodic Array Structures Utilizing Smart *National Research Council hitrodoetion Mesoscale Periodic Arlay Structures (MPAS, also known as crystalline
Littlefield, C.; Garnavich, P.; Magno, K.; Applegate, A.; Pogge, R.; Irwin, J.; Marion, G. H.; Kirshner, R.; Vinko, J.
2013-06-15
We present time-resolved spectroscopy and photometry of CSS 120422:111127+571239 (=SBS 1108+574), a recently discovered SU UMa-type dwarf nova whose 55 minute orbital period is well below the cataclysmic variable (CV) period minimum of {approx}78 minutes. In contrast with most other known CVs, its spectrum features He I emission of comparable strength to the Balmer lines, implying a hydrogen abundance less than 0.1 of long-period CVs-but still at least 10 times higher than that in AM CVn stars. Together, the short orbital period and remarkable helium-to-hydrogen ratio suggest that mass transfer in CSS 120422 began near the end of the donor star's main-sequence lifetime, meaning that this CV is a strong candidate progenitor of an AM CVn system as described by Podsiadlowski et al. Moreover, a Doppler tomogram of the H{alpha} line reveals two distinct regions of enhanced emission. While one is the result of the stream-disk impact, the other is probably attributable to spiral disk structure generated when material in the outer disk achieves a 2:1 orbital resonance with respect to the donor.
Kumar, Pankaj; Cho, Kyung-Suk
2015-01-01
We report decaying quasi-periodic intensity oscillations in the X-ray (6-12 keV) and extreme ultraviolet (EUV) channels (131, 94, 1600, 304 \\AA) observed by the Fermi GBM (Gamma-ray Burst Monitor) and SDO/AIA, respectively, during a C-class flare. The estimated period of oscillation and decay time in the X-ray channel (6-12 keV) was about 202 s and 154 s, respectively. A similar oscillation period was detected at the footpoint of the arcade loops in the AIA 1600 and 304 \\AA channels. Simultaneously, AIA hot channels (94 and 131 \\AA) reveal propagating EUV disturbances bouncing back and forth between the footpoints of the arcade loops. The period of the oscillation and decay time were about 409 s and 1121 s, respectively. The characteristic phase speed of the wave is about 560 km/s for about 115 Mm loop length, which is roughly consistent with the sound speed at the temperature about 10-16 MK (480-608 km/s). These EUV oscillations are consistent with the SOHO/SUMER Doppler-shift oscillations interpreted as the...
E. Minguzzi
2009-09-04
Every time function on spacetime gives a (continuous) total preordering of the spacetime events which respects the notion of causal precedence. The problem of the existence of a (semi-)time function on spacetime and the problem of recovering the causal structure starting from the set of time functions are studied. It is pointed out that these problems have an analog in the field of microeconomics known as utility theory. In a chronological spacetime the semi-time functions correspond to the utilities for the chronological relation, while in a K-causal (stably causal) spacetime the time functions correspond to the utilities for the K^+ relation (Seifert's relation). By exploiting this analogy, we are able to import some mathematical results, most notably Peleg's and Levin's theorems, to the spacetime framework. As a consequence, we prove that a K-causal (i.e. stably causal) spacetime admits a time function and that the time or temporal functions can be used to recover the K^+ (or Seifert) relation which indeed turns out to be the intersection of the time or temporal orderings. This result tells us in which circumstances it is possible to recover the chronological or causal relation starting from the set of time or temporal functions allowed by the spacetime. Moreover, it is proved that a chronological spacetime in which the closure of the causal relation is transitive (for instance a reflective spacetime) admits a semi-time function. Along the way a new proof avoiding smoothing techniques is given that the existence of a time function implies stable causality, and a new short proof of the equivalence between K-causality and stable causality is given which takes advantage of Levin's theorem and smoothing techniques.
Time-Resonant Tokamak Plasma Edge Instabilities?
Webster, A J; Calderon, F A; Chapman, S C; Delabie, E; Dodt, D; Felton, R; Todd, T N; Maviglia, F; Morris, J; Riccardo, V; Alper, B; Brezinsek, S; Coad, P; Likonen, J; Rubel, M; Contributors, JET EFDA
2013-01-01
For a two week period during the Joint European Torus (JET) 2012 experimental campaign, the same high confinement plasma was repeated 151 times. The dataset was analysed to produce a probability density function (pdf) for the waiting times between edge-localised plasma instabilities ("ELMS"). The result was entirely unexpected. Instead of a smooth single peaked pdf, a succession of 4-5 sharp maxima and minima uniformly separated by 7-8 millisecond intervals was found. Here we explore the causes of this newly observed phenomenon, and conclude that it is either due to a self-organised plasma phenomenon or an interaction between the plasma and a real-time control system. If the maxima are a result of "resonant" frequencies at which ELMs can be triggered more easily, then future ELM control techniques can, and probably will, use them. Either way, these results demand a deeper understanding of the ELMing process.
Time Domain Reflectometry Theory
Palermo, Sam
Time Domain Reflectometry Theory Application Note 1304-2 For Use with Agilent 86100 Infiniium DCA #12;2 The most general approach to evaluating the time domain response of any electromagnetic system a concise presentation of the fundamentals of TDR and then relates these fundamentals to the parameters
Beyond periodic orbits: An example in nonhydrogenic atoms
Dando, P.A.; Monteiro, T.S.; Delande, D.; Taylor, K.T. (Department of Mathematics, Royal Holloway, University of London, Egham, Surrey, TW20 0EX (United Kingdom) Laboratoire Kastler-Brossel, Universite Pierre et Marie Curie, 4 place Jussieu, F-75005 Paris (France) Department of Applied Mathematics and Theoretical Physics, Queen's University Belfast, Belfast, BT7 1NN (United Kingdom))
1995-02-13
The spectrum of hydrogen in a magnetic field is a paradigm of quantum chaos and may be analyzed accurately by periodic-orbit-type theories. In nonhydrogenic atoms, the core induces pure quantum effects, especially additional spectral modulations, which cannot be analyzed reliably in terms of classical orbits and their stability parameters. Provided core-scattered waves are included consistently, core-scattered modulations as well as corrected amplitudes for primitive orbits are in excellent agreement with quantum results. We consider whether these systems correspond to quantum chaos.
Bott-Kitaev Periodic Table and the Diagonal Map
R. Kennedy; M. R. Zirnbauer
2014-12-15
Building on the 10-way symmetry classification of disordered fermions, the authors have recently given a homotopy-theoretic proof of Kitaev's "Periodic Table" for topological insulators and superconductors. The present paper offers an introduction to the physical setting and the mathematical model used. Basic to the proof is the so-called Diagonal Map, a natural transformation akin to the Bott map of algebraic topology, which increases by one unit both the momentum-space dimension and the symmetry index of translation-invariant ground states of gapped free-fermion systems. This mapping is illustrated here with a few examples of interest.
PARC Periodical: Volume 5, Issue 3 | Photosynthetic Antenna Research Center
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
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Property:Building/StartPeriod | Open Energy Information
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Devaux, Fabrice
2015-01-01
We report an application of the tri-dimensional pseudo-spectral time domain algorithm, that solves with accuracy the nonlinear Maxwell's equations, to predict second harmonic generation in lithium niobate ridge-type waveguides with high index contrast. Characteristics of the nonlinear process such as conversion efficiency as well as impact of the multimode character of the waveguide are investigated as a function of the waveguide geometry in uniformly and periodically poled medium.
An analysis of periodic heat flow through a plane slab
Gibson, Daniel Morgan
1958-01-01
= heat ener;;y ter perature temperature at end o" time interval w8 nor~el distance from the surface in contact t. ~ith the fluid mhose te", . perature va~ies time prefix, a finite increment densit~J of the slab Sbs '* the fluid. v... INT. HiICH GLIC"' Zigure 2 The al. ;, ebra'c e-lressions for calculating7 the amount of ener'-y er terin;. = an7 interior slice through eaca of its l&oundaries during a finite time interval nQ and. the con- sequent change in energy content...
Ekoto, Dr Isaac; Peterson, Dr. Brian; Szybist, James P; Northrop, Dr. William
2015-01-01
A central challenge for efficient auto-ignition controlled low-temperature gasoline combustion (LTGC) engines has been achieving the combustion phasing needed to reach stable performance over a wide operating regime. The negative valve overlap (NVO) strategy has been explored as a way to improve combustion stability through a combination of charge heating and altered reactivity via a recompression stroke with a pilot fuel injection. The study objective was to analyze the thermal and chemical effects on NVO-period energy recovery. The analysis leveraged experimental gas sampling results obtained from a single-cylinder LTGC engine along with cylinder pressure measurements and custom data reduction methods used to estimate period thermodynamic properties. The engine was fueled by either iso-octane or ethanol, and operated under sweeps of NVO-period oxygen concentration, injection timing, and fueling rate. Gas sampling at the end of the NVO period was performed via a custom dump-valve apparatus, with detailed sample speciation by in-house gas chromatography. The balance of NVO-period input and output energy flows was calculated in terms of fuel energy, work, heat loss, and change in sensible energy. Experiment results were complemented by detailed chemistry single-zone reactor simulations performed at relevant mixing and thermodynamic conditions, with results used to evaluate ignition behavior and expected energy recovery yields. For the intermediate bulk-gas temperatures present during the NVO period (900-1100 K), weak negative temperature coefficient behavior with iso-octane fueling significantly lengthened ignition delays relative to similar ethanol fueled conditions. Faster ethanol ignition chemistry led to lower recovered fuel intermediate yields relative to similar iso-octane fueled conditions due to more complete fuel oxidation. From the energy analysis it was found that increased NVO-period global equivalence ratio, either from lower NVOperiod oxygen concentrations or higher fueling rates, in general led to a greater fraction of net recovered fuel energy and work as heat losses were minimized. These observations were supported by complementary single-zone reactor model results, which further indicated that kinetic time-scales favor chemical energy-consuming exothermic oxidation over slower endothermic reformation. Nonetheless, fuel energy recovery close to the thermodynamic equilibrium solution was achieved for baseline conditions that featured 4% NVO-period oxygen concentration.
Periodicity of the solar full-disk magnetic fields
Xiang, N. B.; Qu, Z. N.; Zhai, Q. [National Astronomical Observatories/Yunnan Observatory, CAS, Kunming 650011 (China)
2014-07-01
A full-disk solar magnetogram has been measured each day since 1970 January 19, and the daily Magnetic Plage Strength Index (MPSI) and the daily Mount Wilson Sunspot Index (MWSI) were calculated for each magnetogram at the Mount Wilson Observatory. The MPSI and MWSI are used to investigate the periodicity of the solar full-disk magnetic activity through autocorrelation analyses. Just two periods, the solar cycle and the rotation cycle, are determined in both the MPSI (the solar full-disk weak magnetic field activity) and MWSI (the solar full-disk strong magnetic field activity) with no annual signal found. The solar cycle for MPSI (10.83 yr) is found to be obviously longer than that for MWSI (9.77 yr). The rotation cycle is determined to be 26.8 ± 0.63 sidereal days for MPSI and 27.4 ± 2.4 sidereal days for MWSI. The rotation cycle length for MPSI is found to fluctuate around 27 days within a very small amplitude, but for MWSI it obviously temporally varies with a rather large amplitude. The rotation cycle for MWSI seems longer near solar minimum than at solar maximum. Cross-correlation analyses of daily MPSI and MWSI are carried out, and it is inferred that the MPSI components partly come from relatively early MWSI measurements.
Ferromagnetism in the two-dimensional periodic Anderson model
Batista, C. D.; Bonca, J.; Gubernatis, J. E.
2001-05-01
Using the constrained-path Monte Carlo method, we studied the magnetic properties of the two-dimensional periodic Anderson model for electron fillings between 1/4 and 1/2. We also derived two effective low-energy theories to assist in interpreting the numerical results. For 1/4 filling, we found that the system can be a Mott or a charge-transfer insulator, depending on the relative values of the Coulomb interaction and the charge-transfer gap between the two noninteracting bands. The insulator may be a paramagnet or antiferromagnet. We concentrated on the effect of electron doping on these insulating phases. Upon doping we obtained a partially saturated ferromagnetic phase for low concentrations of conduction electrons. If the system were a charge-transfer insulator, we would find that the ferromagnetism is induced by the well-known Ruderman-Kittel-Kasuya-Yosida interaction. However, we found a novel correlated hopping mechanism inducing the ferromagnetism in the region where the nondoped system is a Mott insulator. Our regions of ferromagnetism spanned a much smaller doping range than suggested by recent slave boson and dynamical mean-field theory calculations, but they were consistent with that obtained by density-matrix renormalization group calculations of the one-dimensional periodic Anderson model.
Martin, A.D.
1986-05-09
Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay provides a first output signal at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits latch the high resolution data to form a first synchronizing data set. A selected time interval has been preset to internal counters and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses count down the counters to generate an internal pulse delayed by an internal which is functionally related to the preset time interval. A second LCD corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD to generate a second set of synchronizing data which is complementary with the first set of synchronizing data for presentation to logic circuits. The logic circuits further delay the internal output signal with the internal pulses. The final delayed output signal thereafter enables the output pulse generator to produce the desired output pulse at the preset time delay interval following input of the trigger pulse.
Multi-period optimization of pavement management systems
Yoo, Jaewook
2004-09-30
The purpose of this research is to develop a model and solution methodology for selecting and scheduling timely and cost-effective maintenance, rehabilitation, and reconstruction activities (M & R) for each pavement section ...
Reducing EnergyPlus Run Time For Code Compliance Tools
Athalye, Rahul A.; Gowri, Krishnan; Schultz, Robert W.; Glazer, Jason
2014-09-12
Integration of the EnergyPlus ™ simulation engine into performance-based code compliance software raises a concern about simulation run time, which impacts timely feedback of compliance results to the user. EnergyPlus annual simulations for proposed and code baseline building models, and mechanical equipment sizing result in simulation run times beyond acceptable limits. This paper presents a study that compares the results of a shortened simulation time period using 4 weeks of hourly weather data (one per quarter), to an annual simulation using full 52 weeks of hourly weather data. Three representative building types based on DOE Prototype Building Models and three climate zones were used for determining the validity of using a shortened simulation run period. Further sensitivity analysis and run time comparisons were made to evaluate the robustness and run time savings of using this approach. The results of this analysis show that the shortened simulation run period provides compliance index calculations within 1% of those predicted using annual simulation results, and typically saves about 75% of simulation run time.
Broader source: Energy.gov [DOE]
Energy Conservation Program for Consumer Products: Test Procedures for Furnaces and Boilers, Comment Period Extension
Kairoscope : coordinating time socially
Martin, Reed Eric
2010-01-01
If everyone says time is relative, why is it still so rigidly defined? There have been many attempts to address the issue of coordinating schedules, but each of these attempts runs into an issue of rigidity: in order to ...
Moses, David (David Patrick)
2015-01-01
This project is a time capsule of the oil economy, created by entombing everyday objects made from and powered by petroleum into a landscape that spatially recreates the processes of drilling and fracking a contemporary ...
Rubinfeld, Ronitt
Sublinear time algorithms represent a new paradigm in computing, where an algorithm must give some sort of an answer after inspecting only a very small portion of the input. We discuss the types of answers that one can ...
McInnis, Martha Jane
1982-01-01
Physical manifestations of time occur in natural forms of all sizes. Architectural form serves as shelter while providing a built envelope of human life, simultaneously influencing and influenced by energetic activities ...
Center for Human Reliability Studies
2007-05-01
The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user
Center for Human Reliability Studies
2007-05-01
The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user.
Chapin, Kimberly R.
1997-01-01
TIME IN QUANTUM MECHANICS A Thesis by KIMBERLY R. CHAPIN Submitted to Texas A8M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved as to style and content by: Marian O. Scully (Chair... of Committee) Edward S. Fry (Member) aan Laane (Member) Thomas W. Adair, III (Head of Department) August 1997 Major Subject: Physics TIME IN QIJANTUM MECHANICS A Thesis by KIMBERLY R. CHAPIN Submitted to the Oflice of Graduate Studies of Texas A...
Dries Sels; Michiel Wouters
2015-01-22
The problem of time is a deep paradox in our physical description of the world. According to Aristotle's relational theory, time is a measure of change and does not exist on its own. In contrast, quantum mechanics, just like Newtonian mechanics, is equipped with a master clock that dictates the evolution of a system. This clock is infinitely precise and tacitly supplied free of charge from outside physics. Not only does this absolute time make it notoriously difficult to make a consistent theory of quantum gravity, it is also the underlying problem in establishing the second law. Indeed, contrary to our experience, the Wheeler-deWitt equation --a canonical quantization of general relativity-- predicts a static universe. Similarly, when simply concerned with the dynamics of a closed quantum system, there is no second law because the Von Neumann entropy is invariant under unitary transformations. Here we are mainly concerned with the latter problem and we show that it can be resolved by attributing a minimal amount of resources to the measurement of time. Although there is an absolute time in quantum mechanics, an observer can only establish a time by measuring a clock. For a local measurement, the minimal entropy production is equal to the number of ticks. This lower bound is attained by a black hole.
Distinguished trajectories in time dependent vector fields
J. A. Jimenez Madrid; Ana M. Mancho
2009-02-16
We introduce a new definition of distinguished trajectory that generalises the concepts of fixed point and periodic orbit to aperiodic dynamical systems. This new definition is valid for identifying distinguished trajectories with hyperbolic and non-hyperbolic types of stability. The definition is implemented numerically and the procedure consist in determining a path of limit coordinates. It has been successfully applied to known examples of distinguished trajectories. In the context of highly aperiodic realistic flows our definition characterises distinguished trajectories in finite time intervals, and states that outside these intervals trajectories are no longer distinguished.
Real-Time Demand Side Energy Management
Victor, A.; Brodkorb, M.
2006-01-01
• Provides periodic energy consumption reports Demand-Side Energy Management • Compares actual energy cost against defined dynamic targets • Alerts responsible personnel when corrective action is needed • Provides a list of recommended actions... stream_source_info ESL-IE-06-05-24.pdf.txt stream_content_type text/plain stream_size 17485 Content-Encoding UTF-8 stream_name ESL-IE-06-05-24.pdf.txt Content-Type text/plain; charset=UTF-8 Real-Time Demand Side Energy...
All-sky Search for Periodic Gravitational Waves in the Full S5 LIGO Data
J. Abadie; B. P. Abbott; R. Abbott; T. D. Abbott; M. Abernathy; T. Accadia; F. Acernese; C. Adams; R. Adhikari; C. Affeldt; P. Ajith; B. Allen; G. S. Allen; E. Amador Ceron; D. Amariutei; R. S. Amin; S. B. Anderson; W. G. Anderson; K. Arai; M. A. Arain; M. C. Araya; S. M. Aston; P. Astone; D. Atkinson; P. Aufmuth; C. Aulbert; B. E. Aylott; S. Babak; P. Baker; G. Ballardin; S. Ballmer; D. Barker; F. Barone; B. Barr; P. Barriga; L. Barsotti; M. Barsuglia; M. A. Barton; I. Bartos; R. Bassiri; M. Bastarrika; A. Basti; J. Batch; J. Bauchrowitz; Th. S. Bauer; M. Bebronne; B. Behnke; M. G. Beker; A. S. Bell; A. Belletoile; I. Belopolski; M. Benacquista; J. M. Berliner; A. Bertolini; J. Betzwieser; N. Beveridge; P. T. Beyersdorf; I. A. Bilenko; G. Billingsley; J. Birch; R. Biswas; M. Bitossi; M. A. Bizouard; E. Black; J. K. Blackburn; L. Blackburn; D. Blair; B. Bland; M. Blom; O. Bock; T. P. Bodiya; C. Bogan; R. Bondarescu; F. Bondu; L. Bonelli; R. Bonnand; R. Bork; M. Born; V. Boschi; S. Bose; L. Bosi; B. Bouhou; S. Braccini; C. Bradaschia; P. R. Brady; V. B. Braginsky; M. Branchesi; J. E. Brau; J. Breyer; T. Briant; D. O. Bridges; A. Brillet; M. Brinkmann; V. Brisson; M. Britzger; A. F. Brooks; D. A. Brown; A. Brummit; T. Bulik; H. J. Bulten; A. Buonanno; J. Burguet--Castell; O. Burmeister; D. Buskulic; C. Buy; R. L. Byer; L. Cadonati; G. Cagnoli; J. Cain; E. Calloni; J. B. Camp; P. Campsie; J. Cannizzo; K. Cannon; B. Canuel; J. Cao; C. D. Capano; F. Carbognani; S. Caride; S. Caudill; M. Cavaglià; F. Cavalier; R. Cavalieri; G. Cella; C. Cepeda; E. Cesarini; O. Chaibi; T. Chalermsongsak; E. Chalkley; P. Charlton; E. Chassande-Mottin; S. Chelkowski; Y. Chen; A. Chincarini; A. Chiummo; H. Cho; N. Christensen; S. S. Y. Chua; C. T. Y. Chung; S. Chung; G. Ciani; F. Clara; D. E. Clark; J. Clark; J. H. Clayton; F. Cleva; E. Coccia; P. -F. Cohadon; C. N. Colacino; J. Colas; A. Colla; M. Colombini; A. Conte; R. Conte; D. Cook; T. R. Corbitt; M. Cordier; N. Cornish; A. Corsi; C. A. Costa; M. Coughlin; J. -P. Coulon; P. Couvares; D. M. Coward; D. C. Coyne; J. D. E. Creighton; T. D. Creighton; A. M. Cruise; A. Cumming; L. Cunningham; E. Cuoco; R. M. Cutler; K. Dahl; S. L. Danilishin; R. Dannenberg; S. D'Antonio; K. Danzmann; V. Dattilo; B. Daudert; H. Daveloza; M. Davier; G. Davies; E. J. Daw; R. Day; T. Dayanga; R. De Rosa; D. DeBra; G. Debreczeni; J. Degallaix; W. Del Pozzo; M. del Prete; T. Dent; V. Dergachev; R. DeRosa; R. DeSalvo; S. Dhurandhar; L. Di Fiore; A. Di Lieto; I. Di Palma; M. Di Paolo Emilio; A. Di Virgilio; M. Díaz; A. Dietz; F. Donovan; K. L. Dooley; S. Dorsher; M. Drago; R. W. P. Drever; J. C. Driggers; Z. Du; J. -C. Dumas; S. Dwyer; T. Eberle; M. Edgar; M. Edwards; A. Effler; P. Ehrens; G. Endr?czi; R. Engel; T. Etzel; K. Evans; M. Evans; T. Evans; M. Factourovich; V. Fafone; S. Fairhurst; Y. Fan; B. F. Farr; W. Farr; D. Fazi; H. Fehrmann; D. Feldbaum; I. Ferrante; F. Fidecaro; L. S. Finn; I. Fiori; R. P. Fisher; R. Flaminio; M. Flanigan; S. Foley; E. Forsi; L. A. Forte; N. Fotopoulos; J. -D. Fournier; J. Franc; S. Frasca; F. Frasconi; M. Frede; M. Frei; Z. Frei; A. Freise; R. Frey; T. T. Fricke; D. Friedrich; P. Fritschel; V. V. Frolov; P. J. Fulda; M. Fyffe; M. Galimberti; L. Gammaitoni; M. R. Ganija; J. Garcia; J. A. Garofoli; F. Garufi; M. E. Gáspár; G. Gemme; R. Geng; E. Genin; A. Gennai; L. Á. Gergely; S. Ghosh; J. A. Giaime; S. Giampanis; K. D. Giardina; A. Giazotto; C. Gill; E. Goetz; L. M. Goggin; G. González; M. L. Gorodetsky; S. Goßler; R. Gouaty; C. Graef; M. Granata; A. Grant; S. Gras; C. Gray; N. Gray; R. J. S. Greenhalgh; A. M. Gretarsson; C. Greverie; R. Grosso; H. Grote; S. Grunewald; G. M. Guidi; C. Guido; R. Gupta; E. K. Gustafson; R. Gustafson; T. Ha; B. Hage; J. M. Hallam; D. Hammer; G. Hammond; J. Hanks; C. Hanna; J. Hanson; J. Harms; G. M. Harry; I. W. Harry; E. D. Harstad; M. T. Hartman; K. Haughian; K. Hayama; J. -F. Hayau; T. Hayler; J. Heefner; A. Heidmann; M. C. Heintze; H. Heitmann; P. Hello; M. A. Hendry; I. S. Heng; A. W. Heptonstall; V. Herrera; M. Hewitson; S. Hild; D. Hoak; K. A. Hodge; K. Holt; T. Hong; S. Hooper; D. J. Hosken; J. Hough; E. J. Howell; B. Hughey; S. Husa; S. H. Huttner; T. Huynh-Dinh; D. R. Ingram; R. Inta; T. Isogai; A. Ivanov; K. Izumi; M. Jacobson; H. Jang; P. Jaranowski; W. W. Johnson; D. I. Jones; G. Jones; R. Jones; L. Ju; P. Kalmus; V. Kalogera; I. Kamaretsos; S. Kandhasamy; G. Kang; J. B. Kanner; E. Katsavounidis; W. Katzman; H. Kaufer; K. Kawabe; S. Kawamura; F. Kawazoe; W. Kells; D. G. Keppel; Z. Keresztes; A. Khalaidovski; F. Y. Khalili; E. A. Khazanov; B. Kim; C. Kim; D. Kim; H. Kim; K. Kim; N. Kim; Y. -M. Kim; P. J. King; M. Kinsey; D. L. Kinzel; J. S. Kissel; S. Klimenko; K. Kokeyama; V. Kondrashov; R. Kopparapu; S. Koranda; W. Z. Korth; I. Kowalska; D. Kozak; V. Kringel; S. Krishnamurthy; B. Krishnan; A. Królak
2011-10-02
We report on an all-sky search for periodic gravitational waves in the frequency band 50-800 Hz and with the frequency time derivative in the range of 0 through -6e-9 Hz/s. Such a signal could be produced by a nearby spinning and slightly non-axisymmetric isolated neutron star in our galaxy. After recent improvements in the search program that yielded a 10x increase in computational efficiency, we have searched in two years of data collected during LIGO's fifth science run and have obtained the most sensitive all-sky upper limits on gravitational wave strain to date. Near 150 Hz our upper limit on worst-case linearly polarized strain amplitude $h_0$ is 1e-24, while at the high end of our frequency range we achieve a worst-case upper limit of 3.8e-24 for all polarizations and sky locations. These results constitute a factor of two improvement upon previously published data. A new detection pipeline utilizing a Loosely Coherent algorithm was able to follow up weaker outliers, increasing the volume of space where signals can be detected by a factor of 10, but has not revealed any gravitational wave signals. The pipeline has been tested for robustness with respect to deviations from the model of an isolated neutron star, such as caused by a low-mass or long-period binary companion.
All-sky search for periodic gravitational waves in LIGO S4 data
Abbott, B; Adhikari, R; Agresti, J; Ajith, P; Allen, B; Amin, R; Anderson, S B; Anderson, W G; Arain, M; Araya, M; Armandula, H; Ashley, M; Aston, S; Aufmuth, P; Aulbert, C; Babak, S; Ballmer, S; Bantilan, H; Barish, B C; Barker, C; Barker, D; Barr, B; Barriga, P; Barton, M A; Bayer, K; Belczynski, K; Betzwieser, J; Beyersdorf, P T; Bhawal, B; Bilenko, I A; Billingsley, G; Biswas, R; Black, E; Blackburn, K; Blackburn, L; Blair, D; Bland, B; Bogenstahl, J; Bogue, L; Bork, R; Boschi, V; Bose, S; Brady, P R; Braginsky, V B; Brau, J E; Brinkmann, M; Brooks, A; Brown, D A; Bullington, A; Bunkowski, A; Buonanno, A; Burmeister, O; Busby, D; Byer, R L; Cadonati, L; Cagnoli, G; Camp, J B; Cannizzo, J; Cannon, K; Cantley, C A; Cao, J; Cardenas, L; Casey, M M; Castaldi, G; Cepeda, C; Chalkey, E; Charlton, P; Chatterji, S; Chelkowski, S; Chen, Y; Chiadini, F; Chin, D; Chin, E; Chow, J; Christensen, N; Clark, J; Cochrane, P; Cokelaer, T; Colacino, C N; Coldwell, R; Conte, R; Cook, D; Corbitt, T; Coward, D; Coyne, D; Creighton, J D E; Creighton, T D; Croce, R P; Crooks, D R M; Cruise, A M; Cumming, A; Dalrymple, J; D'Ambrosio, E; Danzmann, K; Davies, G; De Bra, D; Degallaix, J; Degree, M; Demma, T; Dergachev, V; Desai, S; DeSalvo, R; Dhurandhar, S; Daz, M; Dickson, J; Di Credico, A; Diederichs, G; Dietz, A; Doomes, E E; Drever, R W P; Dumas, J C; Dupuis, R J; Dwyer, J G; Ehrens, P; Espinoza, E; Etzel, T; Evans, M; Evans, T; Fairhurst, S; Fan, Y; Fazi, D; Fejer, M M; Finn, L S; Fiumara, V; Fotopoulos, N; Franzen, A; Franzen, K Y; Freise, A; Frey, R; Fricke, T; Fritschel, P; Frolov, V V; Fyffe, M; Galdi, V; Garofoli, J; Gholami, I; Giaime, J A; Giampanis, S; Giardina, K D; Goda, K; Goetz, E; Goggin, L M; González, G; Gossler, S; Grant, A; Gras, S; Gray, a C; Gray, M; Greenhalgh, J; Gretarsson, A M; Grosso, R; Grote, H; Grünewald, S; Günther, M; Gustafson, R; Hage, B; Hammer, D; Hanna, C; Hanson, J; Harms, J; Harry, G; Harstad, E; Hayler, T; Heefner, J; Heng, I S; Heptonstall, A; Heurs, M; Hewitson, M; Hild, S; Hirose, E; Hoak, D; Hosken, D; Hough, J; Howell, E; Hoyland, D; Huttner, S H; Ingram, D; Innerhofer, E; Ito, M; Itoh, Y; Ivanov, A; Jackrel, D; Johnson, B; Johnson, W W; Jones, D I; Jones, G; Jones, R; Ju, L; Kalmus, Peter Ignaz Paul; Kalogera, V; Kasprzyk, D; Katsavounidis, E; Kawabe, K; Kawamura, S; Kawazoe, F; Kells, W; Keppel, D G; Khalili, F Ya; Kim, C; King, P; Kissel, J S; Klimenko, S; Kokeyama, K; Kondrashov, V; Kopparapu, R K; Kozak, D; Krishnan, B; Kwee, P; Lam, P K; Landry, M; Lantz, B; Lazzarini, A; Lee, B; Lei, M; Leiner, J; Leonhardt, V; Leonor, I; Libbrecht, K; Lindquist, P; Lockerbie, N A; Longo, M; Lormand, M; Lubinski, M; Luck, H; Machenschalk, B; MacInnis, M; Mageswaran, M; Mailand, K; Malec, M; Mandic, V; Marano, S; Marka, S; Markowitz, J; Maros, E; Martin, I; Marx, J N; Mason, K; Matone, L; Matta, V; Mavalvala, a N; McCarthy, R; McClelland, D E; McGuire, S C; McHugh, M; McKenzie, K; McNabb, J W C; McWilliams, S; Meier, T; Melissinos, A; Mendell, G; Mercer, R A; Meshkov, S; Messaritaki, E; Messenger, C J; Meyers, D; Mikhailov, E; Mitra, S; Mitrofanov, V P; Mitselmakher, G; Mittleman, R; Miyakawa, O; Mohanty, S; Moreno, G; Mossavi, K; Mow Lowry, C; Moylan, A; Mudge, D; Müller, G; Mukherjee, S; Muller-Ebhardt, H; Munch, J; Murray, P; Myers, E; Myers, J; Nash, T; Newton, G; Nishizawa, A; Numata, K; O'Reilly, B; O'Shaughnessy, R; Ottaway, D J; Overmier, H; Owen, B J; Pan, Y; Papa, M A; Parameshwaraiah, V; Patel, P; Pedraza, M; Penn, S; Pierro, V; Pinto, I M; Pitkin, M; Pletsch, H; Plissi, M V; Postiglione, F; Prix, R; Quetschke, V; Raab, F; Rabeling, D; Radkins, H; Rahkola, R; Rainer, N; Rakhmanov, M; Ramsunder, M; Rawlins, K; Ray-Majumder, S; Re, V; Rehbein, H; Reid, S; Reitze, D H; Ribichini, L; Riesen, R; Riles, K; Rivera, B; Robertson, N A; Robinson, C; Robinson, E L; Roddy, S; Rodríguez, A; Rogan, A M; Rollins, J; Romano, J D; Romie, J; Route, R; Rowan, S; Rüdiger, A; Ruet, L; Russell, P; Ryan, K; Sakata, S; Samidi, M; Sancho de la Jordana, L; Sandberg, V; Sannibale, V; Saraf, S; Sarin, P; Sathyaprakash, B S; Sato, S; Saulson, P R; Savage, R; Savov, P; Schediwy, S; Schilling, R; Schnabel, R; Schofield, R; Schutz, B F; Schwinberg, P; Scott, S M; Searle, A C; Sears, B; Seifert, F; Sellers, D; Sengupta, A S; Shawhan, P; Shoemaker, D H; Sibley, A; Sidles, J A; Siemens, X; Sigg, D; Sinha, S; Sintes, A M; Slagmolen, B J J; Slutsky, J; Smith, J R; Smith, M R; Somiya, K; Strain, K A; Strom, D M; Stuver, A; Summerscales, T Z; Sun, K X; Sung, M; Sutton, P J; Takahashi, H; Tanner, D B; Tarallo, M; Taylor, R; Taylor, R; Thacker, J; Thorne, K A; Thorne, K S; Thüring, A; Tokmakov, K V; Torres, C; Torrie, C; Traylor, G; Trias, M; Tyler, W; Ugolini, D; Ungarelli, C; Urbanek, K; Vahlbruch, H; Vallisneri, M; Van Den Broeck, C; Varvella, M; Vass, S; Vecchio, A; Veitch, J; Veitch, P; Villar, A; Vorvick, C
2007-01-01
We report on an all-sky search with the LIGO detectors for periodic gravitational waves in the frequency range 50-1000 Hz and with the frequency's time derivative in the range -1.0E-8 Hz/s to zero. Data from the fourth LIGO science run (S4) have been used in this search. Three different semi-coherent methods of transforming and summing strain power from Short Fourier Transforms (SFTs) of the calibrated data have been used. The first, known as "StackSlide", averages normalized power from each SFT. A "weighted Hough" scheme is also developed and used, and which also allows for a multi-interferometer search. The third method, known as "PowerFlux", is a variant of the StackSlide method in which the power is weighted before summing. In both the weighted Hough and PowerFlux methods, the weights are chosen according to the noise and detector antenna-pattern to maximize the signal-to-noise ratio. The respective advantages and disadvantages of these methods are discussed. Observing no evidence of periodic gravitationa...
Gu Zhanji; Ge Weigao [Department of Computer Science, Hainan Normal University, Haikou, HaiNan 571158 (China) and Department of Applied Mathematics, Beijing Institute of Technology, Beijing 100081 (China); Department of Applied Mathematics, Beijing Institute of Technology, Beijing 100081 (China)
2006-09-15
By using the continuation theorem of coincidence degree theory and constructing suitable Lyapunov functions, we study the existence, uniqueness, and global exponential stability of periodic solution for shunting inhibitory cellular neural networks with impulses, dx{sub ij}/dt=-a{sub ij}x{sub ij}-{sigma}{sub C{sub K}{sub 1}}{sub (set-membershipsign)=N{sub r}{sub (i,j)}C{sub ij}{sup kl}f{sub ij}[x{sub kl}(t)]x{sub ij}+L{sub ij}(t), t>0,t{ne}t{sub k}; {delta}x{sub ij}(t{sub k})=x{sub ij}(t{sub k}{sup +})-x{sub ij}(t{sub k}{sup -})=I{sub k}[x{sub ij}(t{sub k})], k=1,2,... . Furthermore, the numerical simulation shows that our system can occur in many forms of complexities, including periodic oscillation and chaotic strange attractor. To the best of our knowledge, these results have been obtained for the first time. Some researchers have introduced impulses into their models, but analogous results have never been found.
Absolute Timing of the Crab Pulsar with RXTE
Arnold H. Rots; Keith Jahoda; Andrew G. Lyne
2004-03-08
We have monitored the phase of the main X-ray pulse of the Crab pulsar with the Rossi X-ray Timing Explorer (RXTE) for almost eight years, since the start of the mission in January 1996. The absolute time of RXTE's clock is sufficiently accurate to allow this phase to be compared directly with the radio profile. Our monitoring observations of the pulsar took place bi-weekly (during the periods when it was at least 30 degrees from the Sun) and we correlated the data with radio timing ephemerides derived from observations made at Jodrell Bank. We have determined the phase of the X-ray main pulse for each observation with a typical error in the individual data points of 50 us. The total ensemble is consistent with a phase that is constant over the monitoring period, with the X-ray pulse leading the radio pulse by 0.0102+/-0.0012 period in phase, or 344+/-40 us in time. The error estimate is dominated by a systematic error of 40 us in the radio data, arising from uncertainties in the variable amount of pulse delay due to interstellar scattering and instrumental calibration. The statistical error is 0.00015 period, or 5 us. The separation of the main pulse and interpulse appears to be unchanging at time scales of a year or less, with an average value of 0.4001+/-0.0002 period. There is no apparent variation in these values with energy over the 2-30 keV range. The lag between the radio and X-ray pulses may be constant in phase (rotational) or constant in time (linear pathlength). We are not (yet) able to distinguish between these two interpretations.
Assessing historical global sulfur emission patterns for the period 1850--1990
Lefohn, A.S.; Husar, J.D.; Husar, R.B.; Brimblecombe, P.
1996-07-19
Anthropogenic sulfur dioxide emissions from energy-producing and metal production activities have become an important factor in better understanding the relationship between humans and the environment. Concerns about (1) acid rain effects on the environment and (2) anthropogenic aerosols affecting possible global change have prompted interest in the transformation and fate of sulfur in the environment. One step in assessing the importance of sulfur emissions is the development of a reliable regional emission inventory of sulfur as a function of time. The objective of this research effort was to create a homogeneous database for historical sulfur emission estimates for the world. The time from 1850--1990 was selected to include the period of industrialization form the time the main production of fuels and minerals began until the most recent year for which complete production data exist. This research effort attempts to correct some of the deficiencies associated with previous global sulfur emission estimates by (1) identifying those production activities that resulted in sulfur emissions by country and (2) calculating historical emission trends by country across years. An important component of this study was the comparison of the sulfur emission results with those of previous studies.
Variable Selection and Inference for Multi-period Forecasting Problems
Pesaran, M Hashem; Pick, Andreas; Timmermann, Allan
?t,x?t)?. Multi-period forecasts of yt can then be obtained iteratively using a conventional VAR of the form zt = µz + ( Ap(L) Bq(L) Cr(L) Ds(L) ) zt?1 + ?t, (10) where p and q are the lag order of yt and xt in the equation for yt and r and s is the lag order... , i.e. Cr(L) and Bq(L) in particular. To deal with this issue, a conditional factor-augmentation approach can be used. In this approach, the large-dimensional xt-vector is condensed into a subset of factors, fˆ t, of dimension m < M , used to summarize...
Transverse commensurability effect for vortices on periodic pinning arrays
Reichhardt, Charles; Reichhardt, Cynthia J
2008-01-01
Using computer simulations, we demonstrate a type of commensurability that occurs for vortices moving longitudinally through periodic pinning arrays in the presence of an additional transverse driving force. As a function of vortex density, there is a series of broad maxima in the transverse critical depinning force that do not fall at the matching fields where the number of vortices equals an integer multiple of the number of pinning sites. The commensurability effects are associated with dynamical states in which evenly spaced structures consisting of one or more moving rows of vortices form between rows of pinning sites. Remarkably, the critical transverse depinning force can be more than an order of magnitude larger than the longitudinal depinning force.
Experimental evidence of planar channeling in a periodically bent crystal
Bagli, E; Bellucci, V; Berra, E; Camattari, R; De Salvador, D; Germogli, G; Guidi, V; Lanzoni, L; Lietti, D; Mazzolari, A; Prest, M; Tikhomirov, V V; Vallazza, E
2014-01-01
The usage of a Crystalline Undulator (CU) has been identified as a promising solution for generating powerful and monochromatic $\\gamma$-rays. A CU was fabricated at SSL through the grooving method, i.e., by the manufacturing of a series of periodical grooves on the major surfaces of a crystal. The CU was extensively characterized both morphologically via optical interferometry at SSL and structurally via X-ray diffraction at ESRF. Then, it was finally tested for channeling with a 400 GeV/c proton beam at CERN. The experimental results were compared to Monte Carlo simulations. Evidence of planar channeling in the CU was firmly observed. Finally, the emission spectrum of the positron beam interacting with the CU was simulated for possible usage in currently existing facilities.
Short-Period RF Undulator for a SASE Nanometer source
Jay L. Hirshfield
2001-12-21
Analysis is described towards development of a RF undulator with a period < 1 cm, an undulator parameter K of the order of unity, and a gap greater than 2.25 mm. The application for the undulator is for a SASE source to produce 1 nm wavelength radiation using a low energy electron beam in the range 1-2 GeV. Particle orbit calculations in a conventional standing-wave resonator configuration show that the presence of a co-propagating component of RF field can cause deleterious motion for the undulating electrons that can seriously degrade their radiation spectrum. To obviate this problem, resonator designs were devised in which only the counter-propagating field components interact with the particles. Two resonator configurations with the same undulator parameter K = 0.4 have been devised and are described in this report.
Quasi-periodic oscillations from relativistic hydrodynamical slender tori
Mishra, B; Manousakis, A; Fragile, P C; Paumard, T; Klu?niak, W
2015-01-01
We simulate an oscillating purely hydrodynamical torus with constant specific angular mo- mentum around a Schwarzschild black hole. The goal is to search for quasi-periodic oscil- lations (QPOs) in the light curve of the torus. The initial torus setup is subjected to radial, vertical and diagonal (combination of radial and vertical) velocity perturbations. The hydro- dynamical simulations are performed using the general relativistic magnetohydrodynamics code Cosmos++ and ray-traced using the GYOTO code. We found that a horizontal velocity perturbation triggers the radial and plus modes, while a vertical velocity perturbation trig- gers the vertical and X modes. The diagonal perturbation gives a combination of the modes triggered in the radial and vertical perturbations.
Physics Division progress report for period ending September 30, 1984
Livingston, A.B. (ed.)
1985-01-01
The research activities of the Division are centered primarily in three areas: experimental nuclear physics, experimental atomic physics, and theoretical nuclear and atomic physics. The largest of these efforts, experimental nuclear physics, is dominated by the heavy ion research program. A major responsibility under this program is the operation of the Holifield Heavy Ion Research Facility as a national user facility. During the period of this report, the facility has begun routine operation for the experimental program. The experimental atomic physics program has two components: the accelerator-based studies of basic collisional phenomena and the studies in support of the controlled fusion program. Also associated with the fusion-related studies are a plasma diagnostics program and the operation of an atomic physics data center. The theoretical physics program, both nuclear and atomic, is covered. This program has benefited this year from the success of the VAX-AP computer system and from the increase in manpower provided by the ORNL/University of Tennessee Distinguished Scientist Program. Smaller programs in applications and high-energy physics are summarized. During the period of this report, we continued to explore possible future extensions of the Holifield Facility. We retain a strong interest in a relativistic heavy-ion collider in the 10 x 10 GeV/nuclear energy range. The ideas for such a facility, described in last year's report, have been modified to utilize the HHIRF 25 MV tandem accelerator as the first stage. Finally, the report concludes with some general information on publications, Division activities, and personnel changes.
High harmonic generation from periodic potentials driven by few-cycle laser pulses
Guan, Zhong; Bian, Xue-Bin
2015-01-01
We investigate the high harmonic generation (HHG) from solids by simulating the dynamics of a single active electron in periodic potentials. The corresponding time-dependent Schr\\"odinger equations (TDSE) are solved numerically by using B-spline basis sets in coordinate space. The energy band structure and wave vectors can be directly retrived from the eigenfunctions. The harmonic spectra obtained agree well with the results simulated by TDSE in $k$ space using Bloch states and show a two-plateau structure. Both of the cutoff energies of the two plateaus in the harmonic spectrum scale linearly with the field strength. We also study HHG driven by intense few-cycle laser pulses and find that the cutoff energy of the harmonic spectrum is as sensitive to the changes of the carrier envelope phase, as to HHG from gas samples, which suggests recollision pictures in HHG as found by recent experiments (Nature {\\bf 522}, 462 (2015)).
High field pulsed microwiggler comprising a conductive tube with periodically space slots
Warren, R.W.
1992-09-01
A microwiggler assembly produces large magnetic fields for oscillating charged particle beams, particularly electron beams for free electron laser (FEL) application. A tube of electrically conductive material is formed with radial slots axially spaced at the period of the electron beam. The slots have alternate 180[degree] relationships and are formed to a maximum depth of 0.6 to 0.7 times the tube circumference. An optimum slot depth is selected to eliminate magnetic quadrupole fields within the microwiggler as determined from a conventional pulsed wire technique. Suitable slot configurations include single slits, double slits, triple slits, and elliptical slots. An axial electron beam direction is maintained by experimentally placing end slits adjacent entrance and exit portions of the assembly, where the end slit depth is determined by use of the pulsed wire technique outside the tube. 10 figs.
High field pulsed microwiggler comprising a conductive tube with periodically space slots
Warren, Roger W. (Santa Fe, NM)
1992-01-01
A microwiggler assembly produces large magnetic fields for oscillating ched particle beams, particularly electron beams for free electron laser (FEL) application. A tube of electrically conductive material is formed with radial slots axially spaced at the period of the electron beam. The slots have alternate 180.degree. relationships and are formed to a maximum depth of 0.6 to 0.7 times the tube circumference. An optimum slot depth is selected to eliminate magnetic quadrupole fields within the microwiggler as determined from a conventional pulsed wire technique. Suitable slot configurations include single slits, double slits, triple slits, and elliptical slots. An axial electron beam direction is maintained by experimentally placing end slits adjacent entrance and exit portions of the assembly, where the end slit depth is determined by use of the pulsed wire technique outside the tube.
Neighboring Interactions in a Periodic Plasmonic Material for Solar-Thermal Energy Conversion
Musho, Terence D; Coppens, Zackary J
2015-01-01
A periodic plasmonic meta-material was studied using finite-difference time domain (FDTD) method to investigate the influence of neighboring particles on the near unity optical absorptivity. The meta-material was constructed as a silver nanoparticle (20-90nm) situated above an alumina (Al$_2$O$_3$) dielectric environment. A full parametric sweep of the particle width and the dielectric thickness was conducted. Computational results identified several resonances between the metal-dielectric and metal-air that have potential to broadening the response through stacked geometry. A significant coupled resonance between the metal-dielectric resonance and a cavity resonance between particles was capture as a function of dielectric thickness. This coupled resonance was not evident below dielectric thicknesses of 40nm and above cavity widths of 20nm. Additionally, a noticeable propagating surface plasmon polariton resonance was predicted when the particle width was half the unit cell length.
Loki, Io: New groundbased observations and a model describing the change from periodic overturn
Julie A. Rathbun; John R. Spencer
2006-05-09
Loki Patera is the most powerful volcano in the solar system. We have obtained measurements of Loki's 3.5 micron brightness from NASA's Infrared Telescope Facility (IRTF) and have witnessed a change from the periodic behavior previously noted. While Loki brightened by a factor of several every 540 days prior to 2001, from 2001 through 2004 Loki remained at a constant, medium brightness. We have constructed a quantitative model of Loki as a basaltic lava lake whose solidified crust overturns when it becomes buoyantly unstable. By altering the speed at which the overturn propagates across the patera, we can match our groundbased brightness data. In addition, we can match other data taken at other times and wavelengths. By slowing the propagation speed dramatically, we can match the observations from 2001-2004. This slowing may be due to a small change in volatile content in the magma.
Superfluid Dynamics of a Bose-Einstein Condensate in a Periodic Potential
C. Menotti; A. Smerzi; A. Trombettoni
2003-10-31
We investigate the superfluid properties of a Bose-Einstein condensate (BEC) trapped in a one dimensional periodic potential. We study, both analytically (in the tight binding limit) and numerically, the Bloch chemical potential, the Bloch energy and the Bogoliubov dispersion relation, and we introduce {\\it two} different, density dependent, effective masses and group velocities. The Bogoliubov spectrum predicts the existence of sound waves, and the arising of energetic and dynamical instabilities at critical values of the BEC quasi-momentum which dramatically affect its coherence properties. We investigate the dependence of the dipole and Bloch oscillation frequencies in terms of an effective mass averaged over the density of the condensate. We illustrate our results with several animations obtained solving numerically the time-dependent Gross-Pitaevskii equation.
Maximum population transfer in a periodically driven two-level system
P. M. Poggi; F. J. Arranz; R. M. Benito; F. Borondo; D. A. Wisniacki
2014-12-03
We study the dynamics of a two-level quantum system under the influence of sinusoidal driving in the intermediate frequency regime. Analyzing the Floquet quasienergy spectrum, we find combinations of the field parameters for which population transfer is optimal and takes place through a series of well defined steps of fixed duration. We also show how the corresponding evolution operator can be approximated at all times by a very simple analytical expression. We propose this model as being specially suitable for treating periodic driving at avoided crossings found in complex multi-level systems, and thus show a relevant application of our results to designing a control protocol in a realistic molecular model
Search for periodic gravitational radiation with the ALLEGRO gravitational wave detector
E. Mauceli; M. P. McHugh; W. O. Hamilton; W. W. Johnson; A. Morse
2000-07-11
We describe the search for a continuous signal of gravitational radiation from a rotating neutron star in the data taken by the ALLEGRO gravitational wave detector in early 1994. Since ALLEGRO is sensitive at frequencies near 1 kHz, only neutron stars with spin periods near 2 ms are potential sources. There are no known sources of this typ e for ALLEGRO, so we directed the search towards both the galactic center and the globular clus ter 47 Tucanae. The analysis puts a constraint of roughly $8 \\times 10^{-24}$ at frequencies near 1 kHz on the gravitational strain emitted from pulsar spin-down in either 47 Tucanae or the galactic center.
General model selection estimation of a periodic regression with a Gaussian noise
Konev, Victor; 10.1007/s10463-008-0193-1
2010-01-01
This paper considers the problem of estimating a periodic function in a continuous time regression model with an additive stationary gaussian noise having unknown correlation function. A general model selection procedure on the basis of arbitrary projective estimates, which does not need the knowledge of the noise correlation function, is proposed. A non-asymptotic upper bound for quadratic risk (oracle inequality) has been derived under mild conditions on the noise. For the Ornstein-Uhlenbeck noise the risk upper bound is shown to be uniform in the nuisance parameter. In the case of gaussian white noise the constructed procedure has some advantages as compared with the procedure based on the least squares estimates (LSE). The asymptotic minimaxity of the estimates has been proved. The proposed model selection scheme is extended also to the estimation problem based on the discrete data applicably to the situation when high frequency sampling can not be provided.
Unipolar half-cycle pulse generation in asymmetrical media with a periodic subwavelength structure
Song Xiaohong; Yang Weifeng; Zeng Zhinan; Li Ruxin; Xu Zhizhan [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)
2010-11-15
We present a method to generate an extremely short unipolar half-cycle pulse based on resonant propagation of a few-cycle pulse through asymmetrical media with periodic subwavelength structure. Moreover, single- and few-cycle gap solitons with different frequencies are found to split from one incident few-cycle ultrashort pulse. These solitons with various frequencies provide evidence for the generation of different parametric waves during the strong light-matter coupling in asymmetrical media under the extreme nonlinear optics condition. Because of the pulse self-shaping process during the course of resonant propagation, the generated low-frequency sideband and another broadband continuum sideband ranging from the visible to the near-infrared regime couple together, which results in the generation of the subfemtosecond unipolar half-cycle pulse. A time-frequency analysis is preformed which corroborates the mechanism. The generated unipolar half-cycle pulse might be utilized to control and probe the ultrafast electronic dynamics.
Asymptotic reconstruction of the Fourier expansion of inputs of linear time-varying
along with several examples from the automotive engine industry, and with an oscillating water column retrieving wave energy. Keywords: Observers, Linear Time-Varying systems, Periodic input signals, Automotive automotive engine applications. In this domain of engineering, this periodicity stems from a fundamental
Adaptive Time Slotted Channel Hopping for Wireless Sensor Networks
Roussos, George
-located wireless systems utilising the same spectral space. Channel hopping technique was proposed to mitigate the problem via periodic change of the operating frequency, and has been adopted in the form of time slotted-TSCH), an enhanced version of the TSCH aided by blacklisting technique. Complete design and implementation specifics
RESEARCH Open Access Longitudinal variability of time-location/activity
Leistikow, Bruce N.
/weekend), season (warm/cool), sex, employment status, and over the follow-up period. Results: As expected, day- base (CHAD), which houses time-activity data from a large number of studies, are single-day diaries of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits
Predictive Control for Time-Delayed Switching Control Systems
Barth, Eric J.
Predictive Control for Time-Delayed Switching Control Systems Bobby L. Shields Eric J. Barth A methodology is proposed for the control of switching systems characterized by linear system dynamics period determines the effect that the next control input will have on the future output of the system
Computational and experimental study of a forced, time-dependent, methaneair coflow
Long, Marshall B.
steady-state condi- tions. The complex coupling between chemistry and fluid flow in time-varying laminar, a periodic fluc- tuation in time is imposed on the fuel flow rate of a steady laminar flame. The study, D.C. 20052, USA Abstract Forced, time-varying flames are laminar systems that help bridge the gap
Dorf, Martin E.
Time Entry Form Overtime Eligible Staff & Temporaries Harvard Medical School Harvard School of Dental Medicine Action: Reported Time Prior Period Adjustment Name: Week Ending: Employee ID: Job Title: Dept: Job Rcd #: Sun Mon Tue Wed Thu Fri Sat Time Type Tub Org Fund Activity Sub-Act Root Rate Comments
A Tactical Planning Model for a Production Network with Continuous-Time Control
Graves, Stephen C.
1 A Tactical Planning Model for a Production Network with Continuous-Time Control Chee-Chong Teo1 for production planning, the time period needs to be long enough to coincide with the underlying time buckets network. Subject classifications: Inventory/production: tactical planning that considers tradeoffs between
Developmental time windows for axon growth influence neuronal network topology
Lim, Sol
2015-01-01
Early brain connectivity development consists of multiple stages: birth of neurons, their migration and the subsequent growth of axons and dendrites. Each stage occurs within a certain period of time depending on types of neurons and cortical layers. Forming synapses between neurons either by growing axons starting at similar times for all neurons (much-overlapped time windows) or at different time points (less-overlapped) may affect the topological and spatial properties of neuronal networks. Here, we explore the extreme cases of axon formation especially concerning short-distance connectivity during early development, either starting at the same time for all neurons (parallel, i.e. maximally-overlapped time windows) or occurring for each neuron separately one neuron after another (serial, i.e. no overlaps in time windows). For both cases, the number of potential and established synapses remained comparable. Topological and spatial properties, however, differed: neurons that started axon growth early on in s...
Time and Labor 9.1 Time Keeper Payroll -HCSD
Time and Labor 9.1 Time Keeper Payroll - HCSD Version Date: July 2012 #12;COPYRIGHT & TRADEMARKS create a risk of personal injury. If you use this software in dangerous applications, then you shall Guide Time and Labor 9.1 Time Keeper Payroll - HCSD Page iii Table of Contents Time and Labor 9.1 Time
Timed Alternating-Time Temporal Logic Thomas A. Henzinger1
Henzinger, Thomas A.
equally powerful options for updating the state of the game, advancing time, or blocking time. Second, we in order to specify real-time objectives for games played on timed structures. We define the semantics Timed games are a formal model for the synthesis of real-time systems [22, 20]. While much research
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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDidDevelopment TopMetathesisSediments andTheTime-Resolved Time-Resolved
Time series analysis of the lead-lag relationship of freight futures and spot market prices
Gavriilidis, Nikolaos
2008-01-01
This thesis analyzes the relationship between the physical and paper shipping markets. The main objective is to find if one market leads the other by a specific time period so that market players can take advantage from ...
Time-Series Classification of High-Temporal Resolution AVHRR NDVI Imagery of Mexico
Egbert, Stephen L.; Ortega-Huerta, Miguel; Martí nez-Meyer, Enrique; Price, Kevin P.; Peterson, A. Townsend
2000-01-01
Time-series data from wide-field sensors, acquired for the period of a growing season or longer, capitalize on phenological changes in vegetation and make it possible to identify vegetated land cover types in greater detail. ...
Analysis of MODIS 250 m NDVI Using Different Time-Series Data for Crop Type Separability
Lee, Eunmok
2014-08-31
The primary objectives of this research were to: (1) investigate the use of different compositing periods of NDVI values of time-series MODIS 250 m data for distinguishing major crop types on the central Great Plains of ...
Lapa, Celso M.F.; Pereira, Claudio M.N.A. [CNEN, Comissao Nacional de Energia Nuclear, Rua General Severiano 90, Rio de Janeiro, RJ-22-294-900 (Brazil); Frutuoso e Melo, P.F. [COPPE/UFRJ, Cidade Universitaria, Centro de Tecnologia, Bloco G, sala 101, Ilha do Fundao, 21945-970, Rio de Janeiro - RJ (Brazil)
2002-07-01
Nuclear standby safety systems must frequently, be submitted to periodic surveillance tests. The main reason is to detect, as soon as possible, the occurrence of unrevealed failure states. Such interventions may, however, affect the overall system availability due to component outages. Besides, as the components are demanded, deterioration by aging may occur, penalizing again the system performance. By these reasons, planning a good surveillance test policy implies in a trade-off between gains and overheads due to the surveillance test interventions. In order maximize the systems average availability during a given period of time, it has recently been developed a non-periodic surveillance test optimization methodology based on genetic algorithms (GA). The fact of allowing non-periodic tests turns the solution space much more flexible and schedules can be better adjusted, providing gains in the overall system average availability, when compared to those obtained by an optimized periodic tests scheme. The optimization problem becomes, however, more complex. Hence, the use of a powerful optimization technique, such as GAs, is required. Some particular features of certain systems can turn it advisable to introduce other specific constraints in the optimization problem. The Emergency Diesel Generation System (EDGS) of a Nuclear Power Plant (N-PP) is a good example for demonstrating the introduction of seasonal constraints in the optimization problem. This system is responsible for power supply during an external blackout. Therefore, it is desirable during periods of high blackout probability to maintain the system availability as high as possible. Previous applications have demonstrated the robustness and effectiveness of the methodology. However, no seasonal constraints have ever been imposed. This work aims at investigating the application of such methodology in the Angra-II Brazilian NPP EDGS surveillance test policy optimization, considering the blackout probability growth during summer, due to the electrical power demand increase. Here, the model used penalizes test interventions by a continuous modulating function, which depends on the instantaneous blackout probability. Results have demonstrated the ability of the method in adapting the surveillance tests policy to seasonal behaviors. The knowledge acquired by the GA during the searching process has lead to test schedules that drastically minimize the test interventions at periods of high blackout probability. It is compensated by more frequent tests redistributed through the periods of low blackout probability, in order to provide improvement on the overall average availability at the system level. (authors)
Burg, Theresa
Time Activity Time Activity Time Activity Tuesday CLOSED CONFERENCE CLOSED CONFERENCE CLOSED CONFERENCE 2-Jun-15 Wednesday CLOSED CONFERENCE CLOSED CONFERENCE CLOSED CONFERENCE 3-Jun-15 Thursday CLOSED
A Circumbinary Planet in Orbit Around the Short-Period White-Dwarf Eclipsing Binary RR Cae
Qian, S -B; Zhu, L -Y; Dai, Z -B; Lajus, E Fernandez; Baume, G L
2012-01-01
By using six new determined mid-eclipse times together with those collected from the literature, we found that the Observed-Calculated (O-C) curve of RR Cae shows a cyclic change with a period of 11.9 years and an amplitude of 14.3s, while it undergoes an upward parabolic variation (revealing a long-term period increase at a rate of dP/dt =+4.18(+-0.20)x10^(-12). The cyclic change was analyzed for the light-travel time effect that arises from the gravitational influence of a third companion. The mass of the third body was determined to be M_3*sin i' = 4.2(+-0.4) M_{Jup} suggesting that it is a circumbinary giant planet when its orbital inclination is larger than 17.6 degree. The orbital separation of the circumbinary planet from the central eclipsing binary is about 5.3(+-0.6)AU. The period increase is opposite to the changes caused by angular momentum loss via magnetic braking or/and gravitational radiation, nor can it be explained by the mass transfer between both components because of its detached configur...
R. Brout; R. Parentani
1999-02-05
The notion of time in cosmology is revealed through an examination of transition matrix elements of radiative processes occurring in the cosmos. To begin with, the very concept of time is delineated in classical physics in terms of correlations between the succession of configurations which describe a process and a standard trajectory called the clock. The total is an isolated system of fixed energy. This is relevant for cosmology in that the universe is an isolated system which we take to be homogeneous and isotropic. Furthermore, in virtue of the constraint which arises from reparametrization invariance of time, it has total energy zero. Therefore the momentum of the scale factor is determined from the energy of matter. In the quantum theory this is exploited through use of the WKB approximation for the wave function of the scale factor, justified for a large universe. The formalism then gives rise to matrix elements describing matter processes. These are shown to take on the form of usual time dependent quantum amplitudes wherein the temporal dependence is given by a background which is once more fixed by the total energy of matter.
Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]
2004-10-22
DOE O 535.1 establishes the Department's requirements and responsibilities governing time and attendance reporting. The purpose of this revision is to reflect the transition of payroll processing from the Capital Accounting Center to the Defense Finance and Accounting System. Cancels DOE O 3600.1B. Canceled by DOE O 322.1C.
Collar, Juan I.
a checkbook, you can understand which energy options have the promise of supporting humankind - wind, hydro://cfcpwork.uchicago.edu/mailman/listinfo/cafe! A Reality Check on Alternative Energy! #12;A Reality Check on Alternative Energy! Presenter: Liz Moyer! Time a bigger, richer population without fossil fuels (which will definitely run out someday)? Energy is a hot
Marleau, Peter; Brubaker, Erik
2014-11-01
This report provides a short overview of the DNN R&D funded project, Time-Encoded Imagers. The project began in FY11 and concluded in FY14. The Project Description below provides the overall motivation and objectives for the project as well as a summary of programmatic direction. It is followed by a short description of each task and the resulting deliverables.
Time reversal communication system
Candy, James V. (Danville, CA); Meyer, Alan W. (Danville, CA)
2008-12-02
A system of transmitting a signal through a channel medium comprises digitizing the signal, time-reversing the digitized signal, and transmitting the signal through the channel medium. The channel medium may be air, earth, water, tissue, metal, and/or non-metal.
Lyapunov Modes and Time-Correlation Functions for Two-Dimensional Systems
Tooru Taniguchi; Gary P. Morriss
2005-09-27
The relation between the Lyapunov modes (delocalized Lyapunov vectors) and the momentum autocorrelation function is discussed in two-dimensional hard-disk systems. We show numerical evidence that the smallest time-oscillating period of the Lyapunov modes is twice as long as the time-oscillating period of momentum autocorrelation function for both square and rectangular two-dimensional systems with hard-wall boundary conditions.
Nonlinear Dynamics, Magnitude-Period Formula and Forecasts on Earthquake
Yi-Fang Chang
2008-02-02
Based on the geodynamics, an earthquake does not take place until the momentum-energy excess a faulting threshold value of rock due to the movement of the fluid layer under the rock layer and the transport and accumulation of the momentum. From the nonlinear equations of fluid mechanics, a simplified nonlinear solution of momentum corresponding the accumulation of the energy could be derived. Otherwise, a chaos equation could be obtained, in which chaos corresponds to the earthquake, which shows complexity on seismology, and impossibility of exact prediction of earthquakes. But, combining the Carlson-Langer model and the Gutenberg-Richter relation, the magnitude-period formula of the earthquake may be derived approximately, and some results can be calculated quantitatively. For example, we forecast a series of earthquakes of 2004, 2009 and 2014, especially in 2019 in California. Combining the Lorenz model, we discuss the earthquake migration to and fro. Moreover, many external causes for earthquake are merely the initial conditions of this nonlinear system.
Lithospheric Thickness Modeled from Long Period Surface Wave Dispersion
Pasyanos, M E
2008-05-15
The behavior of surface waves at long periods is indicative of subcrustal velocity structure. Using recently published dispersion models, we invert surface wave group velocities for lithospheric structure, including lithospheric thickness, over much of the Eastern Hemisphere, encompassing Eurasia, Africa, and the Indian Ocean. Thicker lithosphere under Precambrian shields and platforms are clearly observed, not only under the large cratons (West Africa, Congo, Baltic, Russia, Siberia, India), but also under smaller blocks like the Tarim Basin and Yangtze craton. In contrast, it is found that remobilized Precambrian structures like the Saharan Shield and Sino-Korean Paraplatform do not have well-established lithospheric keels. The thinnest lithospheric thickness is found under oceanic and continental rifts, as well as along convergence zones. We compare our results to thermal models of continental lithosphere, lithospheric cooling models of oceanic lithosphere, lithosphere-asthenosphere boundary (LAB) estimates from S-wave receiver functions, and velocity variations of global tomography models. In addition to comparing results for the broad region, we examine in detail the regions of Central Africa, Siberia, and Tibet. While there are clear differences in the various estimates, overall the results are generally consistent. Inconsistencies between the estimates may be due to a variety of reasons including lateral and depth resolution differences and the comparison of what may be different lithospheric features.
Physics division. Progress report for period ending September 30, 1996
Ball, S.J. [ed.
1997-04-01
This report covers the research and development activities of the Physics Division for the 1995 and 1996 fiscal years, beginning October 1, 1994, and ending September 30, 1996. The activities of the Division continue to be concentrated in the areas of experimental nuclear physics, experimental atomic physics, and theoretical nuclear and atomic physics. In addition, there are smaller programs in plasma diagnostics and data compilation and evaluation. During the period of this report, there has been considerable success in bringing the Holifield Radioactive Ion Beam Facility (HRIBF) into routine operation. The budgets of the nuclear physics portion of the Division have increased each year in nearly all areas, and several new members have been added to the Division research and development staff. On August 30, 1996, the HRIBF successfully accelerated its first radioactive ion beams, {sup 69}As and {sup 70}As. Prior to this, the heart of the facility, the RIB injector system, was completed, including installation of a remote handling system for the target/ion source assembly. Target and ion source development is likely to be the technical key to success of the HRIBF. We have expanded our efforts in those development areas. Of special note is the development of highly permeable composite targets which have now been shown to allow release of difficult-to-produce radioactive ions such as {sup 17,18}F. A summary of the HRIBF work is provided in Chapter 1, along with supporting activities of the Joint Institute for Heavy Ion Research.
Periodic Accretion Instabilities in the Protostar L1634 IRS 7
Hodapp, Klaus W
2015-01-01
The small molecular cloud Lynds 1634 contains at least three outflow sources. We found one of these, IRS 7, to be variable with a period of 37.14 +/- 0.04 days and an amplitude of approximately 2 mag in the Ks band. The light curve consists of a quiescent phase with little or no variation, and a rapid outburst phase. During the outburst phase, the rapid brightness variation generates light echoes that propagate into the surrounding molecular cloud, allowing a measurement of the distance to IRS 7 of 404 pc +/- 35 pc. We observed only a marginally significant change in the H - K color during the outburst phase. The K-band spectrum of IRS 7 shows CO bandhead emission but its equivalent width does not change significantly with the phase of the light curve. The H_2 1-0 S(1) line emission does not follow the variability of the continuum flux. We also used the imaging data for a proper motion study of the outflows originating from the IRS 7 and the FIR source IRAS 05173-0555, and confirm that these are indeed distin...
Large deviations for quasi-periodic cocycles with singularities
Pedro Duarte; Silvius Klein
2015-07-10
We derive large deviations type (LDT) estimates for linear cocycles over an ergodic multifrequency torus translation. These models are called quasi-periodic cocycles. We make the following assumptions on the model: the translation vector satisfies a generic Diophantine condition, and the fiber action is given by a matrix valued analytic function of several variables which is not identically singular. The LDT estimates obtained here depend on some uniform measurements on the cocycle. Our general results derived in [9] regarding the continuity properties of the Lyapunov exponents (LE) and of the Oseledets filtration and decompositions are then applicable, and we obtain local weak-Holder continuity of these quantities in the presence of gaps in the Lyapunov spectrum. The main new feature of this work is allowing a cocycle depending on several variables to have singularities, i.e. points of non invertibility. This requires a careful analysis of the set of zeros of certain analytic functions of several variables and of the singularities (i.e. negative infinity values) of pluri-subharmonic functions related to the iterates of the cocycle. A refinement of this method in the one variable case leads to a stronger LDT estimate and in turn to a stronger, nearly-Holder modulus of continuity of the LE, Oseledets filtration and Oseledets decomposition. This is a draft of a chapter in our forthcoming research monograph [9].
A renewal theory approach to periodic copolymers with adsorption
Francesco Caravenna; Giambattista Giacomin; Lorenzo Zambotti
2007-10-24
We consider a general model of a heterogeneous polymer chain fluctuating in the proximity of an interface between two selective solvents. The heterogeneous character of the model comes from the fact that the monomer units interact with the solvents and with the interface according to some charges that they carry. The charges repeat themselves along the chain in a periodic fashion. The main question concerning this model is whether the polymer remains tightly close to the interface, a phenomenon called localization, or whether there is a marked preference for one of the two solvents, thus yielding a delocalization phenomenon. In this paper, we present an approach that yields sharp estimates for the partition function of the model in all regimes (localized, delocalized and critical). This, in turn, makes possible a precise pathwise description of the polymer measure, obtaining the full scaling limits of the model. A key point is the closeness of the polymer measure to suitable Markov renewal processes, Markov renewal theory being one of the central mathematical tools of our analysis.
The periodic standing-wave approximation: post-Minkowski computation
Christopher Beetle; Benjamin Bromley; Napoleón Hernández; Richard H. Price
2007-08-08
The periodic standing wave method studies circular orbits of compact objects coupled to helically symmetric standing wave gravitational fields. From this solution an approximation is extracted for the strong field, slowly inspiralling motion of black holes and binary stars. Previous work on this model has dealt with nonlinear scalar models, and with linearized general relativity. Here we present the results of the method for the post-Minkowski (PM) approximation to general relativity, the first step beyond linearized gravity. We compute the PM approximation in two ways: first, via the standard approach of computing linearized gravitational fields and constructing from them quadratic driving sources for second-order fields, and second, by solving the second-order equations as an ``exact'' nonlinear system. The results of these computations have two distinct applications: (i) The computational infrastructure for the ``exact'' PM solution will be directly applicable to full general relativity. (ii) The results will allow us to begin supplying initial data to collaborators running general relativistic evolution codes.
A. UDALSKI; M. KUBIAK; M. SZYMANSKI; J. KALUZNY; M. MATEO; W. KRZEMINSKI
1995-01-09
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.
Transmissions in Graphene through Double Barriers and Periodic Potential
Miloud Mekkaoui; El Bouâzzaoui Choubabi; Ahmed Jellal; Hocine Bahlouli
2015-03-04
Transmission of Dirac fermions through a chip of graphene under the effect of magnetic field and a time vibrating double barrier with frequency $w$ is investigated. Quantum interference within the oscillating barrier has an important effect on quasi-particles tunneling. A combination of both a time dependent potential and a magnetic field generate physical states whose energy is double quantified by the pair of integers $(n, l)$ with high degeneracy. The large number of modes that exist in the energy spectrum presents a colossal difficulty in numerical computations. Thus we were obliged to make a truncation and limit ourselves to the central $(n = 0)$ and two adjacent side band ($n=\\pm 1$).
A periodic and statistical review of the biorhythm theory
Rock, Steven H.
1985-01-01
Committee: Mr. Charles L. Gilmore and Dr. Nay Johnston Nearly 150, 000 industrial worker accidents recorded 1n the State of Colorado were analysed using a computer program designed to determine the status of the victim's biorhythm at the time... the accident occurred and record the results in critical and non-critical categories . The expected rate of occurrence of accidents on biorhythm critical days under random occurrence was statistically compared to the actual rate of occurrence us1ng...
Einstein@Home all-sky search for periodic gravitational waves in LIGO S5 data
Aasi, J; Abbott, B P; Abbott, R; Abbott, T D; Abernathy, M; Accadia, T; Acernese, F; Adams, C; Adams, T; Addesso, P; Adhikari, R; Affeldt, C; Agathos, M; Agatsuma, K; Ajith, P; Allen, B; Allocca, A; Ceron, E Amador; Amariutei, D; Anderson, S B; Anderson, W G; Arai, K; Araya, M C; Ast, S; Aston, S M; Astone, P; Atkinson, D; Aufmuth, P; Aulbert, C; Aylott, B E; Babak, S; Baker, P; Ballardin, G; Ballmer, S; Bao, Y; Barayoga, J C B; Barker, D; Barone, F; Barr, B; Barsotti, L; Barsuglia, M; Barton, M A; Bartos, I; Bassiri, R; Bastarrika, M; Basti, A; Batch, J; Bauchrowitz, J; Bauer, Th S; Bebronne, M; Beck, D; Behnke, B; Bejger, M; Beker, M G; Bell, A S; Bell, C; Belopolski, I; Benacquista, M; Berliner, J M; Bertolini, A; Betzwieser, J; Beveridge, N; Beyersdorf, P T; Bhadbade, T; Bilenko, I A; Billingsley, G; Birch, J; Biswas, R; Bitossi, M; Bizouard, M A; Black, E; Blackburn, J K; Blackburn, L; Blair, D; Bland, B; Blom, M; Bock, O; Bodiya, T P; Bogan, C; Bond, C; Bondarescu, R; Bondu, F; Bonelli, L; Bonnand, R; Bork, R; Born, M; Boschi, V; Bose, S; Bosi, L; Bouhou, B; Braccini, S; Bradaschia, C; Brady, P R; Braginsky, V B; Branchesi, M; Brau, J E; Breyer, J; Briant, T; Bridges, D O; Brillet, A; Brinkmann, M; Brisson, V; Britzger, M; Brooks, A F; Brown, D A; Bulik, T; Bulten, H J; Buonanno, A; Burguet--Castell, J; Buskulic, D; Buy, C; Byer, R L; Cadonati, L; Cagnoli, G; Cagnoli, G; Calloni, E; Camp, J B; Campsie, P; Cannon, K; Canuel, B; Cao, J; Capano, C D; Carbognani, F; Carbone, L; Caride, S; Caudill, S; Cavaglià, M; Cavalier, F; Cavalieri, R; Cella, G; Cepeda, C; Cesarini, E; Chalermsongsak, T; Charlton, P; Chassande-Mottin, E; Chen, W; Chen, X; Chen, Y; Chincarini, A; Chiummo, A; Cho, H S; Chow, J; Christensen, N; Chua, S S Y; Chung, C T Y; Chung, S; Ciani, G; Clara, F; Clark, D E; Clark, J A; Clayton, J H; Cleva, F; Coccia, E; Cohadon, P -F; Colacino, C N; Colla, A; Colombini, M; Conte, A; Conte, R; Cook, D; Corbitt, T R; Cordier, M; Cornish, N; Corsi, A; Costa, C A; Coughlin, M; Coulon, J -P; Couvares, P; Coward, D M; Cowart, M; Coyne, D C; Creighton, J D E; Creighton, T D; Cruise, A M; Cumming, A; Cunningham, L; Cuoco, E; Cutler, R M; Dahl, K; Damjanic, M; Danilishin, S L; D'Antonio, S; Danzmann, K; Dattilo, V; Daudert, B; Daveloza, H; Davier, M; Daw, E J; Day, R; Dayanga, T; De Rosa, R; DeBra, D; Debreczeni, G; Degallaix, J; Del Pozzo, W; Dent, T; Dergachev, V; DeRosa, R; Dhurandhar, S; Di Fiore, L; Di Lieto, A; Di Palma, I; Emilio, M Di Paolo; Di Virgilio, A; Díaz, M; Dietz, A; Dietz, A; Donovan, F; Dooley, K L; Doravari, S; Dorsher, S; Drago, M; Drever, R W P; Driggers, J C; Du, Z; Dumas, J -C; Dwyer, S; Eberle, T; Edgar, M; Edwards, M; Effler, A; Ehrens, P; Endr?czi, G; Engel, R; Etzel, T; Evans, K; Evans, M; Evans, T; Factourovich, M; Fafone, V; Fairhurst, S; Farr, B F; Favata, M; Fazi, D; Fehrmann, H; Feldbaum, D; Ferrante, I; Ferrini, F; Fidecaro, F; Finn, L S; Fiori, I; Fisher, R P; Flaminio, R; Foley, S; Forsi, E; Fotopoulos, N; Fournier, J -D; Franc, J; Franco, S; Frasca, S; Frasconi, F; Frede, M; Frei, M A; Frei, Z; Freise, A; Frey, R; Fricke, T T; Friedrich, D; Fritschel, P; Frolov, V V; Fujimoto, M -K; Fulda, P J; Fyffe, M; Gair, J; Galimberti, M; Gammaitoni, L; Garcia, J; Garufi, F; Gáspár, M E; Gelencser, G; Gemme, G; Genin, E; Gennai, A; Gergely, L Á; Ghosh, S; Giaime, J A; Giampanis, S; Giardina, K D; Giazotto, A; Gil-Casanova, S; Gill, C; Gleason, J; Goetz, E; González, G; Gorodetsky, M L; Goßler, S; Gouaty, R; Graef, C; Graff, P B; Granata, M; Grant, A; Gray, C; Greenhalgh, R J S; Gretarsson, A M; Griffo, C; Grote, H; Grover, K; Grunewald, S; Guidi, G M; Guido, C; Gupta, R; Gustafson, E K; Gustafson, R; Hallam, J M; Hammer, D; Hammond, G; Hanks, J; Hanna, C; Hanson, J; Harms, J; Harry, G M; Harry, I W; Harstad, E D; Hartman, M T; Haughian, K; Hayama, K; Hayau, J -F; Heefner, J; Heidmann, A; Heitmann, H; Hello, P; Hendry, M A; Heng, I S; Heptonstall, A W; Herrera, V; Heurs, M; Hewitson, M; Hild, S; Hoak, D; Hodge, K A; Holt, K; Holtrop, M; Hong, T; Hooper, S; Hough, J; Howell, E J; Hughey, B; Husa, S; Huttner, S H; Huynh-Dinh, T; Ingram, D R; Inta, R; Isogai, T; Ivanov, A; Izumi, K; Jacobson, M; James, E; Jang, Y J; Jaranowski, P; Jesse, E; Johnson, W W; Jones, D I; Jones, R; Jonker, R J G; Ju, L; Kalmus, P; Kalogera, V; Kandhasamy, S; Kang, G; Kanner}, J B; Kasprzack, M; Kasturi, R; Katsavounidis, E; Katzman, W; Kaufer, H; Kaufman, K; Kawabe, K; Kawamura, S; Kawazoe, F; Keitel, D; Kelley, D; Kells, W; Keppel, D G; Keresztes, Z; Khalaidovski, A; Khalili, F Y; Khazanov, E A; Kim, B K; Kim, C; Kim, H; Kim, K; Kim, N; Kim, Y M; King, P J; Kinzel, D L; Kissel, J S; Klimenko, S; Kline, J; Kokeyama, K; Kondrashov, V; Koranda, S; Korth, W Z; Kowalska, I; Kozak, D; Kringel, V; Krishnan, B; Królak, A; Kuehn, G; Kumar, P; Kumar, R; Kurdyumov, R; Kwee, P; Lam, P K; Landry, M; Langley, A; Lantz, B
2012-01-01
This paper presents results of an all-sky searches for periodic gravitational waves in the frequency range [50, 1190] Hz and with frequency derivative ranges of [-2 \\times 10^-9, 1.1 \\times 10^-10] Hz/s for the fifth LIGO science run (S5). The novelty of the search lies in the use of a non-coherent technique based on the Hough-transform to combine the information from coherent searches on timescales of about one day. Because these searches are very computationally intensive, they have been deployed on the Einstein@Home distributed computing project infrastructure. The search presented here is about a factor 3 more sensitive than the previous Einstein@Home search in early S5 LIGO data. The post-processing has left us with eight surviving candidates. We show that deeper follow-up studies rule each of them out. Hence, since no statistically significant gravitational wave signals have been detected, we report upper limits on the intrinsic gravitational wave amplitude h0. For example, in the 0.5 Hz-wide band at 15...
New insights into the quasi-periodic X-ray burster GS 0836-429
Aranzana, E; Kuulkers, E
2015-01-01
GS 0836-429 is a neutron star X-ray transient that displays Type-I X-ray bursts. In 2003 and 2004 it experienced two outbursts in X-rays. We present here an analysis of the system bursting properties during these outbursts. We studied the evolution of the 2003-2004 outbursts in soft X-rays using RXTE (2.5-12 keV; ASM), and in hard X-rays with INTEGRAL (17-80 keV, IBIS/ISGRI). Using data from the JEM-X monitor onboard INTEGRAL we detected 61 Type-I X-ray bursts, and confirm that the source displayed a quasi-periodic burst recurrence time of about 2.3 hours. We improve the characterization of the fuel composition, as well as the description of the typical burst durations and fluences. We estimate the average value of $\\alpha$ to be $49\\pm\\,3$. This value together with the observed burst profiles indicate a regime of a mixed He/H runaway triggered by unstable helium ignition. In addition, we report the detection of four series of double bursts, with burst recurrence times of $\\leq\\,20$ minutes. The measured recu...
Saritepe, S.; Annala, G.
1993-06-01
Bunched beam transfer from one accelerator to another requires coordination and synchronization of many ramped devices. During collider operation timing issues are more complicated since one has to switch from proton injection devices to antiproton injection devices. Proton and antiproton transfers are clearly distinct sequences since protons and antiprotons circulate in opposite directions in the Main Ring (MR) and in the Tevatron. The time bumps are different, the kicker firing delays are different, the kickers and lambertson magnets are different, etc. Antiprotons are too precious to be used for tuning purposes, therefore protons are transferred from the Tevatron back into the Main Ring, tracing the path of antiprotons backwards. This tuning operation is called ``reverse injection.`` Previously, the reverse injection was handled in one supercycle. One batch of uncoalesced bunches was injected into the Tevatron and ejected after 40 seconds. Then the orbit closure was performed in the MR. In the new scheme the lambertson magnets have to be moved and separator polarities have to be switched, activities that cannot be completed in one supercycle. Therefore, the reverse injection sequence was changed. This involved the redefinition of TVBS clock event $D8 as MRBS $D8 thus making it possible to inject 6 proton batches (or coalesced bunches) and eject them one at a time on command, performing orbit closure each time in the MR. Injection devices are clock event driven. The TCLK is used as the reference clock. Certain TCLK events are triggered by the MR beam synchronized clock (MRBS) events. Some delays are measured in terms of MRBS ticks and MR revolutions. See Appendix A for a brief description of the beam synchronized clocks.
Direct calculation of thermal emission for three-dimensionally periodic photonic crystal slabs Received 8 May 2006; published 18 September 2006 We perform direct thermal emission calculations for three, implemented via a finite-difference time- domain algorithm. We demonstrate that emissivity and absorptivity
Copyright 2002 The Financial Times Limited Financial Times (London, England)
with Argentina's capacity to abuse, manipulate, freeze, confiscate and periodically replace the national currency. Furthermore, the public will respond to red-meat populism. Argentina's need for international support in debt
Quinn, H; /SLAC
2009-01-27
This talk briefly reviews three types of time-asymmetry in physics, which I classify as universal, macroscopic and microscopic. Most of the talk is focused on the latter, namely the violation of T-reversal invariance in particle physics theories. In sum tests of microscopic T-invariance, or observations of its violation, are limited by the fact that, while we can measure many processes, only in very few cases can we construct a matched pair of process and inverse process and observe it with sufficient sensitivity to make a test. In both the cases discussed here we can achieve an observable T violation making use of flavor tagging, and in the second case also using the quantum properties of an antisymmetric coherent state of two B mesons to construct a CP-tag. Both these tagging properties depend only on very general properties of the flavor and/or CP quantum numbers and so provide model independent tests for T-invariance violations. The microscopic laws of physics are very close to T-symmetric. There are small effects that give CP- and T-violating processes in three-generation-probing weak decays. Where a T-violating observable can be constructed we see the relationships between T-violation and CP-violation expected in a CPT conserving theory. These microscopic effects are unrelated to the 'arrow of time' that is defined by increasing entropy, or in the time direction defined by the expansion of our Universe.
EIS-0388: Extension of Scoping Period for the Notice of Intent...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Extension of Scoping Period for the Notice of Intent to Prepare an Environmental Impact Statement EIS-0388: Extension of Scoping Period for the Notice of Intent to Prepare an...
EIS-0380: Notice to Extend Comment Period on the Draft Site-Wide...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
to Extend Comment Period on the Draft Site-Wide Environmental Impact Statement EIS-0380: Notice to Extend Comment Period on the Draft Site-Wide Environmental Impact Statement...
The effect of periodic-unsteady wakes, curvature, and pressure gradient on boundary-layer transition
Radke, Robert Edward
1994-01-01
periodic-unsteady wakes. In addition, a turbomachinery cascade test facility with periodic-unsteady inlet flow was designed and manufactured for the next generation of research in this area....
Taxonomy of periodic nets and the design of materials Olaf Delgado-Friedrichs,a
Yaghi, Omar M.
Taxonomy of periodic nets and the design of materials Olaf Delgado-Friedrichs,a Michael O classification (taxonomy) of polyhedra and periodic nets that is appropriate for identifying the structures
Klages, Rainer
Lyapunov instability for a periodic Lorentz gas thermostated by deterministic scattering K assess the nonlinear properties of this dynamical system by numerically calculating its Lyapunov exponents. Based on a revised method for computing Lyapunov exponents, which employs periodic
Victoria, University of
A New Methodology for Frequency Domain Analysis of Wave Energy Converters with Periodically Varying Methodology for Frequency Domain Analysis of Wave Energy Converters with Periodically Varying Physical of Mechanical Engineering) ABSTRACT Within a wave energy converter's operational bandwidth, device operation
Real Time Grid Reliability Management 2005
Eto, Joe; Eto, Joe; Lesieutre, Bernard; Lewis, Nancy Jo; Parashar, Manu
2008-07-07
The increased need to manage California?s electricity grid in real time is a result of the ongoing transition from a system operated by vertically-integrated utilities serving native loads to one operated by an independent system operator supporting competitive energy markets. During this transition period, the traditional approach to reliability management -- construction of new transmission lines -- has not been pursued due to unresolved issues related to the financing and recovery of transmission project costs. In the absence of investments in new transmission infrastructure, the best strategy for managing reliability is to equip system operators with better real-time information about actual operating margins so that they can better understand and manage the risk of operating closer to the edge. A companion strategy is to address known deficiencies in offline modeling tools that are needed to ground the use of improved real-time tools. This project: (1) developed and conducted first-ever demonstrations of two prototype real-time software tools for voltage security assessment and phasor monitoring; and (2) prepared a scoping study on improving load and generator response models. Additional funding through two separate subsequent work authorizations has already been provided to build upon the work initiated in this project.
Progress in Large Period Multilayer Coatings for High Harmonic and Solar Applications
Aquila, Andrew
2008-01-01
large period multilayer coatings for high harmonic and solarBerkeley, CA 94720 Multilayer coatings for normal incidence
DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD JUNE 1, 2001 THROUGH SEPTEMBER 30, 2001
L.C. BROWN
2001-09-30
OAK-B135 DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD JUNE 1, 2001 THROUGH SEPTEMBER 30, 2001
Zhang, Dingzong; Wang, Yanhui; Wang, Dezhen [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)
2013-06-15
Period-doubling and chaos phenomenon have been frequently observed in atmospheric-pressure dielectric-barrier discharges. However, how a normal single period discharge bifurcates into period-doubling state is still unclear. In this paper, by changing the driving frequency, we study numerically the transition mechanisms from a normal single period discharge to a period-doubling state using a one-dimensional self-consistent fluid model. The results show that before a discharge bifurcates into a period-doubling state, it first deviates from its normal operation and transforms into an asymmetric single period discharge mode. Then the weaker discharge in this asymmetric discharge will be enhanced gradually with increasing of the frequency until it makes the subsequent discharge weaken and results in the discharge entering a period-doubling state. In the whole transition process, the spatial distribution of the charged particle density and the electric field plays a definitive role. The conclusions are further confirmed by changing the gap width and the amplitude of the applied voltage.
E ective boundary conditions for laminar ows over periodic rough boundaries
Achdou, Yves
E#27;ective boundary conditions for laminar #29;ows over periodic rough boundaries Yves Achdou #3 are proposed for a laminar #29;ow over a rough wall with periodic roughness elements. These e#27;ective is such an approach ? In this paper, we wish to answer these questions for laminar #29;ows over periodic rough walls
THE EFFECT OF A REFRACTORY PERIOD ON THE POWER SPECTRUM OF NEURONAL DISCHARGE
Bair, Wyeth
produce peaks in the power spectrum near 40 Hz. Key words. neuronal spike trains, refractory periodTHE EFFECT OF A REFRACTORY PERIOD ON THE POWER SPECTRUM OF NEURONAL DISCHARGE JOEL FRANKLIN neuron refractory period and a statistically independent interval due to a stationary external process
Holocene climate instability during the termination of the African Humid Period
Renssen, Hans
Holocene climate instability during the termination of the African Humid Period H. Renssen January 2003; published 25 February 2003. [1] The termination of the Holocene African Humid Period ($9. Goosse, Holocene climate instability during the termination of the African Humid Period, Geophys. Res
Accomplishments in Field Period Assembly for NCSX* This is how we did it
Michael Viola, J. Edwards, T. Brown, L. Dudek, R. Ellis, P. Heitzenroeder, R. Strykowsky and Michael Cole
2009-09-14
The National Compact Stellarator Experiment (NCSX) was a collaborative effort between ORNL and PPPL. PPPL provided the assembly techniques with guidance from ORNL to meet design criteria. The individual vacuum vessel segments, modular coils, trim coils, and toroidal field coils components were delivered to the Field Period Assembly (FPA) crew who then would complete the component assemblies and then assemble the final three field period assemblies, each consisting of two sets of three modular coils assembled over a 120o vacuum vessel segment with the trim coils and toroidal field coils providing the outer layer. The requirements for positioning the modular coils were found to be most demanding. The assembly tolerances required for accurate positioning of the field coil windings in order to generate sufficiently accurate magnetic fields strained state of the art techniques in metrology and alignment and required constant monitoring of assembly steps with laser trackers, measurement arms, and photogrammetry. The FPA activities were being performed concurrently while engineering challenges were being resolved. For example, it was determined that high friction electrically isolated shims were needed between the modular coil interface joints and low distortion welding was required in the nose region of those joints. This took months of analysis and development yet the assembly was not significantly impacted because other assembly tasks could be performed in parallel with ongoing assembly tasks as well as tasks such as advance tooling setup preparation for the eventual welding tasks. The crew technicians developed unique, accurate time saving techniques and tooling which provided significant cost and schedule savings. Project management displayed extraordinary foresight and every opportunity to gain advanced knowledge and develop techniques was taken advantage of. Despite many risk concerns, the cost and schedule performance index was maintained nearly 1.0 during the assembly phase until project cancellation. In this paper, the assembly logic, the engineering challenges, solutions to those challenges and some of the unique and clever assembly techniques, will be presented.
Daiqin Su; T. C. Ralph
2015-07-02
We show that the particle number distribution of diamond modes, modes that are localised in a finite space-time region, are thermal for the Minkowski vacuum state of a massless scalar field, an analogue to the Unruh effect. The temperature of the diamond is inversely proportional to its size. An inertial observer can detect this thermal radiation by coupling to the diamond modes using an appropriate energy scaled detector. We further investigate the correlations between various diamonds and find that entanglement between adjacent diamonds dominates.
Sirshendu Bhattacharyya; Arnab Das; Subinay Dasgupta
2012-08-10
We study the real-time dynamics of a quantum Ising chain driven periodically by instantaneous quenches of the transverse field (the transverse field varying as rectangular wave symmetric about zero). Two interesting phenomena are reported and analyzed: (1) We observe dynamical many-body freezing or DMF (Phys. Rev. B, vol. 82, 172402, 2010), i.e. strongly non-monotonic freezing of the response (transverse magnetization) with respect to the driving parameters (pulse width and height) resulting from equivocal freezing behavior of all the many-body modes. The freezing occurs due to coherent suppression of dynamics of the many-body modes. For certain combination of the pulse height and period, maximal freezing (freezing peaks) are observed. For those parameter values, a massive collapse of the entire Floquet spectrum occurs. (2) Secondly, we observe emergence of a distinct solitary oscillation with a single frequency, which can be much lower than the driving frequency. This slow oscillation, involving many high-energy modes, dominates the response remarkably in the limit of long observation time. We identify this slow oscillation as the unique survivor of destructive quantum interference between the many-body modes. The oscillation is found to decay algebraically with time to a constant value. All the key features are demonstrated analytically with numerical evaluations for specific results.
Francini, Andrea
2013-05-14
An advance is made over the prior art in accordance with the principles of the present invention that is directed to a new approach for a system and method for a buffer management scheme called Periodic Early Discard (PED). The invention builds on the observation that, in presence of TCP traffic, the length of a queue can be stabilized by selection of an appropriate frequency for packet dropping. For any combination of number of TCP connections and distribution of the respective RTT values, there exists an ideal packet drop frequency that prevents the queue from over-flowing or under-flowing. While the value of the ideal packet drop frequency may quickly change over time and is sensitive to the series of TCP connections affected by past packet losses, and most of all is impossible to compute inline, it is possible to approximate it with a margin of error that allows keeping the queue occupancy within a pre-defined range for extended periods of time. The PED scheme aims at tracking the (unknown) ideal packet drop frequency, adjusting the approximated value based on the evolution of the queue occupancy, with corrections of the approximated packet drop frequency that occur at a timescale that is comparable to the aggregate time constant of the set of TCP connections that traverse the queue.
No Time Wasted. 25 years COVRA: Radioactive Waste Management in the Netherlands
Codee, H.D.K.; Verhoef, E.V. [COVRA N.V., Vlissingen (Netherlands)
2008-07-01
Time will render radioactive waste harmless. How can we manage the time radioactive substances remain harmful? Just 'wait and see' or 'marking time' is not an option. We need to isolate the waste from our living environment and control it as long as necessary. December 2007 was a time to commemorate, as the national waste management organisation of the Netherlands, COVRA, celebrated its 12. anniversary. During this period of 25 years a stable policy has been formulated and implemented. For the situation in the Netherlands, it was obvious that a period of long term storage was needed. Both the small volume of waste and the limited financial possibilities are determining factors. Time is needed to let the volume of waste grow and to let the money, needed for disposal, grow in a capital growth fund. A historical overview of the activities of COVRA is presented and lessons learned over a period of 25 years are given. (authors)
R. Staubert; S. Schandl; D. Klochkov; J Wilms; K. Postnov; N. Shakura
2007-02-20
We have studied the long-term (1971-2005) behaviour of the 1.24 sec pulse period and the 35 day precession period of Her X-1 and show that both periods vary in a highly correlated way (see also Staubert et al. 1997 and 2000). When the spin-up rate decreases, the 35 day turn-on period shortens.This correlation is most evident on long time scales (~2000 days),e.g.around four extended spin-down episodes, but also on shorter time scales (a few 100 days) on which quasi-periodic variations are apparent. We argue that the likely common cause is variations of the mass accretion rate onto the neutron star.The data since 1991 allow a continuous sampling and indicate a lag between the turn-on behaviour and the spin behaviour, in the sense that changes are first seen in the spin, about one cycle later in the turn-on. Both the coronal wind model (Schandl & Meyer 1994) as well as the stream-disk model (Shakura et al.999) predict this kind of behaviour.
Detection and discrimination of the periodicity of prime numbers by discrete Fourier transform
Levente Csoka
2015-01-27
A novel representation of a quasi-periodic modified von Mangoldt function L(n) on prime numbers and its decomposition into Fourier series has been investigated. We focus on some particular quantities characterizing the modified von Mangoldt function. The results indicate that prime number progression can be decomposed into periodic sequences. The main approach is to decompose it into sin or cosine function. Basically, it is applied to extract hidden periodicities in seemingly quasi periodic prime function. Numerical evidences were provided to confirm the periodic distribution of primes.
The Periods Discovered by RXTE in Thermonuclear Flash Bursts
T. E. Strohmayer; J. H. Swank; W. Zhang
1998-01-23
Oscillations in the X-ray flux of thermonuclear X-ray bursts have been observed with RXTE from at least 6 low-mass binaries, at frequencies from 330 Hz to 589 Hz. There appear to be preferred relations between the frequencies present during the bursts and those seen in the persistent flux. The amplitude of the oscillations can exceed 50 % near burst onset. Except for a systematic increase in oscillation frequency as the burst progresses, the frequency is stable. Time resolved spectra track increases in the X-ray emitting area due to propagation of the burning front over the neutron star surface, as well as radiation driven expansion of the photosphere. The neutron star mass, radius, and distance can be inferred when spectra are compared to theoretical expectations.
Sayles, Mark; Stasiak, Arkadiusz; Winter, Ian M.
2015-01-12
) of a low F0 (e.g., Plack et al., 2005). In the case of voiced speech sounds, F0 typically corresponds to the vocal-fold vibration rate. The F0 of steady-state and time-varying complex sounds is represented in the temporal pattern of action- potential... distri- butions has been shown to correlate with psychophysical pitch strength for a wide range of pitch-evoking sounds (Cariani and Delgutte, 1996a,b). Contrast of 1 indicates no periodicity at the corresponding F0. Neural mechanisms for complex...
Sloan Digital Sky Survey observing time tracking and efficiency measurement
Eric H. Neilsen, Jr.; Richard G. Kron; William N. Boroski
2002-10-16
Accurate and consistent time tracking is essential for evaluating the efficiency of survey observing operations and identifying areas that need improvement. Off the shelf time tracking software, which requires users to enter activities by hand, proved tedious to use and insufficiently exible. In this paper, we present an alternate time tracking system developed specifically for Sloan Digital Sky Survey observing. This system uses an existing logging system, murmur, to log the beginning and ending times of tracked circumstances, including activities, weather, and problems which effect observing. Operations software automatically generates most entries for routine observing activities; in a night of routine observing, time tracking requires little or no attention from the observing staff. A graphical user interface allows observers to make entries marking time lost to weather and equipment, and to correct inaccurate entries made by the observing software. The last is necessary when the change in activity is not marked by a change in the state of the software or instruments, or when the time is used for engineering or other observing not part of routine survey data collection. A second utility generates reports of time usage from these logs. These reports include totals for the time spent for each observing task, time lost to weather and problems, efficiency statistics for comparison with the survey baseline, and a detailed listing of what activities and problems were present in any covered time period.
Time Valid One-Time Signature for Time-Critical Multicast Data Authentication
Nahrstedt, Klara
malicious attacks. In this paper, we propose a novel signature model Time Valid One-Time Signature (TVTime Valid One-Time Signature for Time-Critical Multicast Data Authentication Qiyan Wang, Himanshu-OTS) to boost the efficiency of regular one-time signature schemes. Based on the TV-OTS model, we design
Advertising Emergency Department Wait Times
Weiner, Scott G
2013-01-01
studies evaluating the advertising of ED wait times. Only 1potentially used for advertising may be inaccurate. AccessedE ditorial Advertising Emergency Department Wait Times Scott
Final Exam Location and Time. Math 162 Fall 2001. Date: Wednesday December 12, 2001. Time: 7:00 pm -9:00 pm. Location: Lambert Fieldhouse ...
Final Exam Location and Time. Math 161 Fall 2001. Date: Friday December 14, 2001. Time: 8:00 am -10:00 am. Location: Lambert Fieldhouse ...
Kaplan, Alexander
format with double line spacing (font Times New Roman, 12 pt; margins: left and up -- 30 mm, right , . 20. , , . 1. 2 , 4 2 ( Times New Roman, 12 pt
Denoising Deterministic Time Series
Steven P. Lalley; Andrew B. Nobel
2006-04-21
This paper is concerned with the problem of recovering a finite, deterministic time series from observations that are corrupted by additive, independent noise. A distinctive feature of this problem is that the available data exhibit long-range dependence and, as a consequence, existing statistical theory and methods are not readily applicable. This paper gives an analysis of the denoising problem that extends recent work of Lalley, but begins from first principles. Both positive and negative results are established. The positive results show that denoising is possible under somewhat restrictive conditions on the additive noise. The negative results show that, under more general conditions on the noise, no procedure can recover the underlying deterministic series.
Real time automated inspection
Fant, K.M.; Fundakowski, R.A.; Levitt, T.S.; Overland, J.E.; Suresh, B.R.; Ulrich, F.W.
1985-05-21
A method and apparatus are described relating to the real time automatic detection and classification of characteristic type surface imperfections occurring on the surfaces of material of interest such as moving hot metal slabs produced by a continuous steel caster. A data camera transversely scans continuous lines of such a surface to sense light intensities of scanned pixels and generates corresponding voltage values. The voltage values are converted to corresponding digital values to form a digital image of the surface which is subsequently processed to form an edge-enhanced image having scan lines characterized by intervals corresponding to the edges of the image. The edge-enhanced image is thresholded to segment out the edges and objects formed by the edges by interval matching and bin tracking. Features of the objects are derived and such features are utilized to classify the objects into characteristic type surface imperfections. 43 figs.
Time encoded radiation imaging
Marleau, Peter; Brubaker, Erik; Kiff, Scott
2014-10-21
The various technologies presented herein relate to detecting nuclear material at a large stand-off distance. An imaging system is presented which can detect nuclear material by utilizing time encoded imaging relating to maximum and minimum radiation particle counts rates. The imaging system is integrated with a data acquisition system that can utilize variations in photon pulse shape to discriminate between neutron and gamma-ray interactions. Modulation in the detected neutron count rates as a function of the angular orientation of the detector due to attenuation of neighboring detectors is utilized to reconstruct the neutron source distribution over 360 degrees around the imaging system. Neutrons (e.g., fast neutrons) and/or gamma-rays are incident upon scintillation material in the imager, the photons generated by the scintillation material are converted to electrical energy from which the respective neutrons/gamma rays can be determined and, accordingly, a direction to, and the location of, a radiation source identified.
Real-time applications of neural nets
Spencer, J.E.
1989-05-01
Producing, accelerating and colliding very high power, low emittance beams for long periods is a formidable problem in real-time control. As energy has grown exponentially in time so has the complexity of the machines and their control systems. Similar growth rates have occurred in many areas, e.g., improved integrated circuits have been paid for with comparable increases in complexity. However, in this case, reliability, capability and cost have improved due to reduced size, high production and increased integration which allow various kinds of feedback. In contrast, most large complex systems (LCS) are perceived to lack such possibilities because only one copy is made. Neural nets, as a metaphor for LCS, suggest ways to circumvent such limitations. It is argued that they are logically equivalent to multi-loop feedback/forward control of faulty systems. While complimentary to AI, they mesh nicely with characteristics desired for real-time systems. Such issues are considered, examples given and possibilities discussed. 21 refs., 6 figs.
Finite-difference time-domain simulation of fusion plasmas at radiofrequency time scales
Smithe, David N. [Tech-X Corporation, 5621 Arapahoe Avenue, Suite A, Boulder, Colorado 80303 (United States)
2007-05-15
Simulation of dense plasmas in the radiofrequency range are typically performed in the frequency domain, i.e., by solving Laplace-transformed Maxwell's equations. This technique is well-suited for the study of linear heating and quasilinear evolution, but does not generalize well to the study of nonlinear phenomena. Conversely, time-domain simulation in this range is difficult because the time scale is long compared to the electron plasma wave period, and in addition, the various cutoff and resonance behaviors within the plasma insure that any explicit finite-difference scheme would be numerically unstable. To resolve this dilemma, explicit finite-difference Maxwell terms are maintained, but a carefully time-centered locally implicit method is introduced to treat the plasma current, such that all linear plasma dispersion behavior is faithfully reproduced at the available temporal and spatial resolution, despite the fact that the simulation time step may exceed the electron gyro and electron plasma time scales by orders of magnitude. Demonstrations are presented of the method for several classical benchmarks, including mode conversion to ion cyclotron wave, cyclotron resonance, propagation into a plasma-wave cutoff, and tunneling through low-density edge plasma.
Time's Ontic Voltage Craig Callender
Callender, Craig
Time's Ontic Voltage Craig Callender Philosophy of time, as practiced throughout the last hundred venue for attacking questions about the nature of time--in sharp contrast to the primary venue slowly in philosophy of time.1 Since twentieth-century analytic philosophy as a whole often drew
Untameable Timed Automata! (Extended Abstract)
Doyen, Laurent
are a widely studied model for realtime systems. Since 8 years, several tools implement this modellife systems. 1 Introduction RealTime Systems Since their introduction by Alur and Dill in [AD94], timed au tomata are one of the most studied models for realtime systems. Numerous works have been devoted
Untameable Timed Automata! (Extended Abstract)
Doyen, Laurent
model for real-time systems. Since 8 years, several tools implement this model and are successfully used for a restricted class of timed automata, which has been sufficient for modeling numerous real-life systems. 1 Introduction Real-Time Systems - Since their introduction by Alur and Dill in [AD94], timed au- tomata are one
On the Problem of Allocating Multicore Virtual Resources to Real-Time Task Pipelines
Lipari, Giuseppe
1 On the Problem of Allocating Multicore Virtual Resources to Real-Time Task Pipelines Giuseppe--Real-time applications that process streams of data can be modelled by a pipeline of tasks, to be executed on a multi-processor system. The pipeline is periodically activated, and each instance must be completed before an end
P-WAVE TIME-LAPSE SEISMIC DATA INTERPRETATION AT RULISON FIELD, PICEANCE BASIN, COLORADO
P-WAVE TIME-LAPSE SEISMIC DATA INTERPRETATION AT RULISON FIELD, PICEANCE BASIN, COLORADO by Donald-lapse seismic surveys, shot by the Reservoir Characterization Project in the fall of 2003 and 2004, at Rulison seismic can monitor tight gas reservoirs, to a limited extent, over a short period of time. Repeat surveys
Lyapunov based continuous-time nonlinear controller redesign for sampled-data implementation
Nesic, Dragan
Lyapunov based continuous-time nonlinear controller redesign for sampled-data implementation, 2004 Abstract: Given a continuous-time controller and a Lyapunov function that shows global asymptotic the sampling period T) of the Lyapunov difference for the sampled-data system with the redesigned controller
XMM-EPIC TIMING MONITORING AT ESAC I. Caballero1,2
Barnstedt, JÃ¼rgen
accuracy of EPIC-pn. It calculates the period of the Crab pulsar in the X-ray regime and compares-pn; calibration; tim- ing. 1. INTRODUCTION The EPIC instruments on board XMM-Newton were suc- cesfully launched et al. 2005. 2. TIMING MONITORING The relative timing accuracy is monitored by calculating the X
PROBABILITY OF ERROR FOR TRAINED UNITARY SPACE-TIME MODULATION OVER A
Swindlehurst, A. Lee
PROBABILITY OF ERROR FOR TRAINED UNITARY SPACE-TIME MODULATION OVER A GAUSS-INNOVATIONS RICIAN probability of error for trained uni- tary space-time modulation over channels with a constant specular trained modulation, assuming that the channel is constant between training periods. All of the above
All-sky Search for Periodic Gravitational Waves in the Full S5 LIGO Data
Abadie, J; Abbott, R; Abbott, T D; Abernathy, M; Accadia, T; Acernese, F; Adams, C; Adhikari, R; Affeldt, C; Ajith, P; Allen, B; Allen, G S; Ceron, E Amador; Amariutei, D; Amin, R S; Anderson, S B; Anderson, W G; Arai, K; Arain, M A; Araya, M C; Aston, S M; Astone, P; Atkinson, D; Aufmuth, P; Aulbert, C; Aylott, B E; Babak, S; Baker, P; Ballardin, G; Ballmer, S; Barker, D; Barone, F; Barr, B; Barriga, P; Barsotti, L; Barsuglia, M; Barton, M A; Bartos, I; Bassiri, R; Bastarrika, M; Basti, A; Batch, J; Bauchrowitz, J; Bauer, Th S; Bebronne, M; Behnke, B; Beker, M G; Bell, A S; Belletoile, A; Belopolski, I; Benacquista, M; Berliner, J M; Bertolini, A; Betzwieser, J; Beveridge, N; Beyersdorf, P T; Bilenko, I A; Billingsley, G; Birch, J; Biswas, R; Bitossi, M; Bizouard, M A; Black, E; Blackburn, J K; Blackburn, L; Blair, D; Bland, B; Blom, M; Bock, O; Bodiya, T P; Bogan, C; Bondarescu, R; Bondu, F; Bonelli, L; Bonnand, R; Bork, R; Born, M; Boschi, V; Bose, S; Bosi, L; Bouhou, B; Braccini, S; Bradaschia, C; Brady, P R; Braginsky, V B; Branchesi, M; Brau, J E; Breyer, J; Briant, T; Bridges, D O; Brillet, A; Brinkmann, M; Brisson, V; Britzger, M; Brooks, A F; Brown, D A; Brummit, A; Bulik, T; Bulten, H J; Buonanno, A; Burguet--Castell, J; Burmeister, O; Buskulic, D; Buy, C; Byer, R L; Cadonati, L; Cagnoli, G; Cain, J; Calloni, E; Camp, J B; Campsie, P; Cannizzo, J; Cannon, K; Canuel, B; Cao, J; Capano, C D; Carbognani, F; Caride, S; Caudill, S; Cavaglià, M; Cavalier, F; Cavalieri, R; Cella, G; Cepeda, C; Cesarini, E; Chaibi, O; Chalermsongsak, T; Chalkley, E; Charlton, P; Chassande-Mottin, E; Chelkowski, S; Chen, Y; Chincarini, A; Chiummo, A; Cho, H; Christensen, N; Chua, S S Y; Chung, C T Y; Chung, S; Ciani, G; Clara, F; Clark, D E; Clark, J; Clayton, J H; Cleva, F; Coccia, E; Cohadon, P -F; Colacino, C N; Colas, J; Colla, A; Colombini, M; Conte, A; Conte, R; Cook, D; Corbitt, T R; Cordier, M; Cornish, N; Corsi, A; Costa, C A; Coughlin, M; Coulon, J -P; Couvares, P; Coward, D M; Coyne, D C; Creighton, J D E; Creighton, T D; Cruise, A M; Cumming, A; Cunningham, L; Cuoco, E; Cutler, R M; Dahl, K; Danilishin, S L; Dannenberg, R; D'Antonio, S; Danzmann, K; Dattilo, V; Daudert, B; Daveloza, H; Davier, M; Davies, G; Daw, E J; Day, R; Dayanga, T; De Rosa, R; DeBra, D; Debreczeni, G; Degallaix, J; Del Pozzo, W; del Prete, M; Dent, T; Dergachev, V; DeRosa, R; DeSalvo, R; Dhurandhar, S; Di Fiore, L; Di Lieto, A; Di Palma, I; Emilio, M Di Paolo; Di Virgilio, A; Díaz, M; Dietz, A; Donovan, F; Dooley, K L; Dorsher, S; Drago, M; Drever, R W P; Driggers, J C; Du, Z; Dumas, J -C; Dwyer, S; Eberle, T; Edgar, M; Edwards, M; Effler, A; Ehrens, P; Endr?czi, G; Engel, R; Etzel, T; Evans, K; Evans, M; Evans, T; Factourovich, M; Fafone, V; Fairhurst, S; Fan, Y; Farr, B F; Farr, W; Fazi, D; Fehrmann, H; Feldbaum, D; Ferrante, I; Fidecaro, F; Finn, L S; Fiori, I; Fisher, R P; Flaminio, R; Flanigan, M; Foley, S; Forsi, E; Forte, L A; Fotopoulos, N; Fournier, J -D; Franc, J; Frasca, S; Frasconi, F; Frede, M; Frei, M; Frei, Z; Freise, A; Frey, R; Fricke, T T; Friedrich, D; Fritschel, P; Frolov, V V; Fulda, P J; Fyffe, M; Galimberti, M; Gammaitoni, L; Ganija, M R; Garcia, J; Garofoli, J A; Garufi, F; Gáspár, M E; Gemme, G; Geng, R; Genin, E; Gennai, A; Gergely, L Á; Ghosh, S; Giaime, J A; Giampanis, S; Giardina, K D; Giazotto, A; Gill, C; Goetz, E; Goggin, L M; González, G; Gorodetsky, M L; Goßler, S; Gouaty, R; Graef, C; Granata, M; Grant, A; Gras, S; Gray, C; Gray, N; Greenhalgh, R J S; Gretarsson, A M; Greverie, C; Grosso, R; Grote, H; Grunewald, S; Guidi, G M; Guido, C; Gupta, R; Gustafson, E K; Gustafson, R; Ha, T; Hage, B; Hallam, J M; Hammer, D; Hammond, G; Hanks, J; Hanna, C; Hanson, J; Harms, J; Harry, G M; Harry, I W; Harstad, E D; Hartman, M T; Haughian, K; Hayama, K; Hayau, J -F; Hayler, T; Heefner, J; Heidmann, A; Heintze, M C; Heitmann, H; Hello, P; Hendry, M A; Heng, I S; Heptonstall, A W; Herrera, V; Hewitson, M; Hild, S; Hoak, D; Hodge, K A; Holt, K; Hong, T; Hooper, S; Hosken, D J; Hough, J; Howell, E J; Hughey, B; Husa, S; Huttner, S H; Huynh-Dinh, T; Ingram, D R; Inta, R; Isogai, T; Ivanov, A; Izumi, K; Jacobson, M; Jang, H; Jaranowski, P; Johnson, W W; Jones, D I; Jones, G; Jones, R; Ju, L; Kalmus, P; Kalogera, V; Kamaretsos, I; Kandhasamy, S; Kang, G; Kanner, J B; Katsavounidis, E; Katzman, W; Kaufer, H; Kawabe, K; Kawamura, S; Kawazoe, F; Kells, W; Keppel, D G; Keresztes, Z; Khalaidovski, A; Khalili, F Y; Khazanov, E A; Kim, B; Kim, C; Kim, D; Kim, H; Kim, K; Kim, N; Kim, Y -M; King, P J; Kinsey, M; Kinzel, D L; Kissel, J S; Klimenko, S; Kokeyama, K; Kondrashov, V; Kopparapu, R; Koranda, S; Korth, W Z; Kowalska, I; Kozak, D; Kringel, V; Krishnamurthy, S; Krishnan, B; Królak, A; Kuehn, G; Kumar, R; Kwee, P; Lam, P K; Landry, M; Lang, M; Lantz, B; Lastzka, N; Lawrie, C; Lazzarini, A; Leaci, P; Lee, C H; Lee, H M
2011-01-01
We report on an all-sky search for periodic gravitational waves in the frequency band 50-800 Hz and with the frequency time derivative in the range of 0 through -6e-9 Hz/s. Such a signal could be produced by a nearby spinning and slightly non-axisymmetric isolated neutron star in our galaxy. After recent improvements in the search program that yielded a 10x increase in computational efficiency, we have searched in two years of data collected during LIGO's fifth science run and have obtained the most sensitive all-sky upper limits on gravitational wave strain to date. Near 150 Hz our upper limit on worst-case linearly polarized strain amplitude $h_0$ is 1e-24, while at the high end of our frequency range we achieve a worst-case upper limit of 3.8e-24 for all polarizations and sky locations. These results constitute a factor of two improvement upon previously published data. A new detection pipeline utilizing a Loosely Coherent algorithm was able to follow up weaker outliers, increasing the volume of space wher...
SGR1806-20: evidence for a superstrong Magnetic Field from Quasi Periodic Oscillations
M. Vietri; L. Stella; G. Israel
2007-02-22
Fast Quasi-Periodic Oscillations (QPOs, frequencies of $\\sim 20 - 1840$ Hz) have been recently discovered in the ringing tail of giant flares from Soft Gamma Repeaters (SGRs), when the luminosity was of order $10^{41}-10^{41.5}$ erg/s. These oscillations persisted for many tens of seconds, remained coherent for up to hundreds of cycles and were observed over a wide range of rotational phases of the neutron stars believed to host SGRs. Therefore these QPOs must have originated from a compact, virtually non-expanding region inside the star's magnetosphere, emitting with a very moderate degree of beaming (if at all). The fastest QPOs imply a luminosity variation of $\\Delta L/\\Delta t \\simeq 6 \\times 10^{43}$ erg s$^{-2}$, the largest luminosity variation ever observed from a compact source. It exceeds by over an order of magnitude the usual Cavallo-Fabian-Rees (CFR) luminosity variability limit for a matter-to-radiation conversion efficiency of 100%. We show that such an extreme variability can be reconciled with the CFR limit if the emitting region is immersed in a magnetic field $\\gtrsim 10^{15}$ G at the star surface, providing independent evidence for the superstrong magnetic fields of magnetars.
KIC 4768731: a bright long-period roAp star in the Kepler Field
Smalley, B; Murphy, S J; Lehmann, H; Kurtz, D W; Holdsworth, D L; Cunha, M S; Balona, L A; Briquet, M; Bruntt, H; de Cat, P; Lampens, P; Thygesen, A O; Uytterhoeven, K
2015-01-01
We report the identification of 61.45 d^-1 (711.2 mu Hz) oscillations, with amplitudes of 62.6-mu mag, in KIC 4768731 (HD 225914) using Kepler photometry. This relatively bright (V=9.17) chemically peculiar star with spectral type A5 Vp SrCr(Eu) has previously been found to exhibit rotational modulation with a period of 5.21 d. Fourier analysis reveals a simple dipole pulsator with an amplitude that has remained stable over a 4-yr time span, but with a frequency that is variable. Analysis of high-resolution spectra yields stellar parameters of T_eff = 8100 +/- 200 K, log g = 4.0 +/- 0.2, [Fe/H] = +0.31 +/- 0.24 and v sin i = 14.8 +/- 1.6 km/s. Line profile variations caused by rotation are also evident. Lines of Sr, Cr, Eu, Mg and Si are strongest when the star is brightest, while Y and Ba vary in anti-phase with the other elements. The abundances of rare earth elements are only modestly enhanced compared to other roAp stars of similar T_eff and log g. Radial velocities in the literature suggest a significant...
Gevorg Poghosyan; Sanchit Matta; Achim Streit; Micha? Bejger; Andrzej Królak
2014-10-14
The parallelization, design and scalability of the \\sky code to search for periodic gravitational waves from rotating neutron stars is discussed. The code is based on an efficient implementation of the F-statistic using the Fast Fourier Transform algorithm. To perform an analysis of data from the advanced LIGO and Virgo gravitational wave detectors' network, which will start operating in 2015, hundreds of millions of CPU hours will be required - the code utilizing the potential of massively parallel supercomputers is therefore mandatory. We have parallelized the code using the Message Passing Interface standard, implemented a mechanism for combining the searches at different sky-positions and frequency bands into one extremely scalable program. The parallel I/O interface is used to escape bottlenecks, when writing the generated data into file system. This allowed to develop a highly scalable computation code, which would enable the data analysis at large scales on acceptable time scales. Benchmarking of the code on a Cray XE6 system was performed to show efficiency of our parallelization concept and to demonstrate scaling up to 50 thousand cores in parallel.
Refined rotational period, pole solution, and shape model for (3200) Phaethon
Ansdell, Megan; Meech, Karen J.; Kaluna, Heather; Hainaut, Olivier; Buie, Marc W.; Bauer, James; Dundon, Luke
2014-09-20
(3200) Phaethon exhibits both comet- and asteroid-like properties, suggesting it could be a rare transitional object such as a dormant comet or previously volatile-rich asteroid. This justifies detailed study of (3200) Phaethon's physical properties as a better understanding of asteroid-comet transition objects can provide insight into minor body evolution. We therefore acquired time series photometry of (3200) Phaethon over 15 nights from 1994 to 2013, primarily using the Tektronix 2048 × 2048 pixel CCD on the University of Hawaii 2.2 m telescope. We utilized light curve inversion to (1) refine (3200) Phaethon's rotational period to P = 3.6032 ± 0.0008 hr; (2) estimate a rotational pole orientation of ? = +85° ± 13° and ? = –20° ± 10°; and (3) derive a shape model. We also used our extensive light curve data set to estimate the slope parameter of (3200) Phaethon's phase curve as G ? 0.06, consistent with C-type asteroids. We discuss how this highly oblique pole orientation with a negative ecliptic latitude supports previous evidence for (3200) Phaethon's origin in the inner main asteroid belt as well as the potential for deeply buried volatiles fueling impulsive yet rare cometary outbursts.
Robustness of the periodic and chaotic orientational behavior of tumbling nematic liquid crystals
Heidenreich, Sebastian; Hess, Siegfried [Institute for Theoretical Physics, Technical University Berlin, Hardenbergstrasse 36, D-10623 (Germany); Ilg, Patrick [Institute for Theoretical Physics, Technical University Berlin, Hardenbergstrasse 36, D-10623 (Germany); Universite Lyon1, Laboratoire de Physique de la Matiere Condensee et Nanostructures, CNRS, UMR5586, F-69622 Villeurbanne Cedex (France)
2006-06-15
The dynamical behavior of molecular alignment strongly affects physical properties of nematic liquid crystals. A theoretical description can be made by a nonlinear relaxation equation of the order parameter and leads to the prediction that rather complex even chaotic orientational behavior occur. Here the influence of fluctuating shear rates on the orientational dynamics especially on chaotic solutions is discussed. With the help of phase portraits and time evolution diagrams, we investigated the influence of different fluctuation strengths on the flow aligned, isotropic, and periodic solutions. To explore the effect of fluctuations on the chaotic behavior, we calculated the largest Lyapunov exponent for different fluctuation strengths. We found in all cases that small fluctuations of the shear rate do not affect the basic features of the dynamics of tumbling nematics. Furthermore, we present an amended potential modeling the isotropic to nematic transition and discuss the equivalence and difference to the commonly used Landau-de Gennes potential. In contrast to the Landau-de Gennes potential, our potential has the advantage to restrict the order parameter to physically admissible values. In the case of extensional flow, we show that the amended potential leads for increasing extensional rate to a better agreement with experimental results.
The backward phase flow method for the Eulerian finite time Lyapunov exponent computations
Leung, Shingyu, E-mail: masyleung@ust.hk [Department of Mathematics, Hong Kong University of Science and Technology, Clear Water Bay (Hong Kong)] [Department of Mathematics, Hong Kong University of Science and Technology, Clear Water Bay (Hong Kong)
2013-12-15
We propose a simple Eulerian approach to compute the moderate to long time flow map for approximating the Lyapunov exponent of a (periodic or aperiodic) dynamical system. The idea is to generalize a recently proposed backward phase flow method which is specially designed for long time level set propagation. Unlike the original phase flow method or the backward phase flow method, which is applicable only to autonomous systems, the current approach can also be applied to any time-dependent (periodic or aperiodic) flow. We will discuss the stability of the proposed method. Numerical examples will be given to demonstrate the effectiveness of the algorithm.
Andrey Melnikov
2012-12-08
We prove the existence of solutions to the Sturm-Liouville (SL) equation -y"(x)+q(x)y(x) = s^2 y(x) with periodic and quasi-periodic potential q(x) using theory of SL vessels, implementing a Backlund transformation of SL equation. In this paper quasi-periodic means a finite sum of periodic integrable functions. The solutions for a general s are explicitly constructed in terms of the solutions zn(x), satisfying the SL equation with initial conditions zn(0)=0, zn'(0)=1 for a discrete Levinson set of numbers s=sn, n-natural number. The tau function tau(x) of the corresponding vessel realizes the given potential via the formula q(x)= - 2(ln(tau(x)))". We also prove an analogue of the inverse scattering theorem in this setting too. Using the notion of "KdV evolutionary vessel", we construct a solution of the Korteweg-de-Vries (KdV) equation q'_t = - 3/2 q q'_x + 1/4 q"'_{xxx}, which coincides for t=0 with a given (periodic or quasi-periodic) potential.
Time-resolved optical photometry of the ultra-compact binary 4U0614+091
Shahbaz, T; Zurita, C; Villaver, E; Hernandez-Peralta, H
2008-01-01
We present a detailed optical study of the ultra-compact X-ray binary 4U0614+091. We have used 63 hrs of time-resolved optical photometry taken with three different telescopes (IAC80, NOT and SPM) to search for optical modulations. The power spectra of each dataset reveals sinusoidal modulations with different periods, which are not always present. The strongest modulation has a period of 51.3 mins, a semi-amplitude of 4.6 mmags, and is present in the IAC80 data. The SPM and NOT data show periods of 42 mins and 64 mins respectively, but with much weaker amplitudes, 2.6 mags and 1.3 mmags respectively. These modulations arise from either X-ray irradiation of the inner face of the secondary star and/or a superhump modulation from the accretion disc, or quasi-periodic modulations in the accretion disc. It is unclear whether these periods/quasi-periodic modulations are related to the orbital period, however, the strongest period of 51.3 mins is close to earlier tentative orbital periods. Further observations take...
Time-resolved optical photometry of the ultra-compact binary 4U0614+091
T. Shahbaz; C. A. Watson; C. Zurita; E. Villaver; H. Hernandez-Peralta
2008-06-09
We present a detailed optical study of the ultra-compact X-ray binary 4U0614+091. We have used 63 hrs of time-resolved optical photometry taken with three different telescopes (IAC80, NOT and SPM) to search for optical modulations. The power spectra of each dataset reveals sinusoidal modulations with different periods, which are not always present. The strongest modulation has a period of 51.3 mins, a semi-amplitude of 4.6 mmags, and is present in the IAC80 data. The SPM and NOT data show periods of 42 mins and 64 mins respectively, but with much weaker amplitudes, 2.6 mags and 1.3 mmags respectively. These modulations arise from either X-ray irradiation of the inner face of the secondary star and/or a superhump modulation from the accretion disc, or quasi-periodic modulations in the accretion disc. It is unclear whether these periods/quasi-periodic modulations are related to the orbital period, however, the strongest period of 51.3 mins is close to earlier tentative orbital periods. Further observations taken over a long base-line are encouraged.
Schneider, Abe
2014-04-09
The main goal of this proposal was to develop and test a novel powertrain solution for the SLH hydroEngine?, a low-cost, efficient low-head hydropower technology. Nearly two-thirds of U.S. renewable electricity is produced by hydropower (EIA 2010). According to the U.S. Department of Energy; this amount could be increased by 50% with small hydropower plants, often using already-existing dams (Hall 2004). There are more than 80,000 existing dams, and of these, less than 4% generate power (Blankinship 2009). In addition, there are over 800 irrigation districts in the U.S., many with multiple, non-power, low-head drops. These existing, non-power dams and irrigation drops could be retrofitted to produce distributed, baseload, renewable energy with appropriate technology. The problem is that most existing dams are low-head, or less than 30 feet in height (Ragon 2009). Only about 2% of the available low-head hydropower resource in the U.S. has been developed, leaving more than 70 GW of annual mean potential low-head capacity untapped (Hall 2004). Natel Energy, Inc. is developing a low-head hydropower turbine that operates efficiently at heads less than 6 meters and is cost-effective for deployment across multiple low-head structures. Because of the unique racetrack-like path taken by the prime-movers in the SLH, a flexible powertrain is required. Historically, the only viable technological solution was roller chain. Despite the having the ability to easily attach blades, roller chain is characterized by significant drawbacks, including high cost, wear, and vibration from chordal action. Advanced carbon-#12;fiber-reinforced timing belts have been recently developed which, coupled with a novel belt attachment system developed by Natel Energy, result in a large reduction in moving parts, reduced mass and cost, and elimination of chordal action for increased fatigue life. The work done in this project affirmatively addressed each of the following 3 major uncertainties concerning a timing-belt based hydroEngine ?powertrain: 1. Can a belt handle the high torques and power loads demanded by the SLH? (Yes.) 2. Can the SLH blades be mounted to belt with a connection that can withstand the loads encountered in operation? (Yes.) 3. Can the belt, with blade attachments, live through the required cyclic loading? (Yes.) The research adds to the general understanding of sustainable small hydropower systems by using innovative system testing to develop and demonstrate performance of a novel powertrain solution, enabling a new type of hydroelectric turbine to be commercially developed. The technical effectiveness of the methods investigated has been shown to be positive through an extensive design and testing process accommodating many constraints and goals, with a major emphasis on high cycle fatigue life. Economic feasibility of the innovations has been demonstrated through many iterations of design for manufacturability and cost reduction. The project is of benefit to the public because it has helped to develop a solution to a major problem -- despite the large available potential for new low-head hydropower, high capital costs and high levelized cost of electricity (LCOE) continue to be major barriers to project development. The hydroEngine? represents a significant innovation, leveraging novel fluid mechanics and mechanical configuration to allow lower-cost turbine manufacture and development of low head hydropower resources.
Enderlein, Jörg
Dead-time optimized time-correlated photon counting instrument with synchronized, independent timing channels Michael Wahla and Hans-Jürgen Rahn PicoQuant GmbH, Rudower Chaussee 29, D-12489 Berlin December 2006; accepted 19 February 2007; published online 23 March 2007 Time-correlated single photon
Time and Labor 9.1 Time Keeper -HCSD
Time and Labor 9.1 Time Keeper - HCSD Version Date: July 2012 #12;COPYRIGHT & TRADEMARKS Copyright create a risk of personal injury. If you use this software in dangerous applications, then you shall
Property:OpenEI/UtilityRate/DemandChargePeriod7FAdj | Open Energy...
Jump to: navigation, search This is a property of type Number. Name: Demand Charge Period 7 Fuel Adj Retrieved from "http:en.openei.orgwindex.php?titleProper...
[2008, 23pp]---On certain period relations for cusp forms on GL_n.pdf
2008-07-24
International Mathematics Research Notices, Vol. 2008, Article ID rnn077, .... sponds to a Hilbert modular form of CM type, then our period relations are formally ...
EIS-0466: Re-opening of Public Scoping Period and Announcement...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Public Scoping Meetings Continued Operation of the Sandia National Laboratories, New Mexico Comment Period Ends: 9122011 Submit Comments to: Ms. Jeanette Norte NNSA Sandia Site...
EIS-0350-S1: Extension of the Public Review and Comment Period...
Broader source: Energy.gov (indexed) [DOE]
Period and Announcement of an Additional Public Hearing for the Draft Supplemental Environmental Impact Statement for the Nuclear Facility Portion of the Chemistry and Metallurgy...
Computer Assisted 'Proof' of the Global Existence of Periodic Orbits in the Rössler System
A. E. Botha; W. Dednam
2014-08-14
The numerical optimized shooting method for finding periodic orbits in nonlinear dynamical systems was employed to determine the existence of periodic orbits in the well-known R\\"ossler system. By optimizing the period $T$ and the three system parameters, $a$, $b$ and $c$, simultaneously, it was found that, for any initial condition $(x_0,y_0,z_0) \\in \\Re^3$, there exists at least one set of optimized parameters corresponding to a periodic orbit passing through $ (x_0,y_0,z_0)$. After a discussion of this result it was concluded that its analytical proof may present an interesting new mathematical challenge.
Measuring the rotation period distribution of field M-dwarfs with Kepler
McQuillan, Amy; Mazeh, Tsevi
2013-01-01
We have analysed 10 months of public data from the Kepler space mission to measure rotation periods of main-sequence stars with masses between 0.3 and 0.55 M_sun. To derive the rotational period we introduce the autocorrelation function and show that it is robust against phase and amplitude modulation and residual instrumental systematics. Of the 2483 stars examined, we detected rotation periods in 1570 (63.2%), representing an increase of a factor ~ 30 in the number of rotation period determination for field M-dwarfs. The periods range from 0.37-69.7 days, with amplitudes ranging from 1.0-140.8 mmags. The rotation period distribution is clearly bimodal, with peaks at ~ 19 and ~ 33 days, hinting at two distinct waves of star formation, a hypothesis that is supported by the fact that slower rotators tend to have larger proper motions. The two peaks of the rotation period distribution form two distinct sequences in period-temperature space, with the period decreasing with increasing temperature, reminiscent of ...
DOE Extends Comment Period on Notice of Inquiry Under the Energy...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Act of 2007, which implements the Convention on Supplementary Compensation for Nuclear Damage. The public comment period will be extended to October 27, 2010. The signed extension...
A Low-Cost, High-Efficiency Periodic Flow Gas Turbine for Distributed Energy Generation
Dr. Adam London
2008-06-20
The proposed effort served as a feasibility study for an innovative, low-cost periodic flow gas turbine capable of realizing efficiencies in the 39-48% range.
EIS-0250-S2 and EIS-0369: Notice of Public Comment Period Extension...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Notice of Public Comment Period Extension and Additional Public Meeting Supplemental Yucca Mountain Rail Corridor and Rail Alignment The Department of Energy announced an...
EIS-0299: Notice of Extension of Comment Period for the Environmental...
Broader source: Energy.gov (indexed) [DOE]
period on the environmental impact statement (EIS) for the Proposed Production of Plutonium-238 for Use in Advanced Radioisotope Power Systems for Future Space Missions from...
Date of Injury Date Time In Time Out
: NORMAL Work Schedule (ie: MF, 8am5pm)First Name Last Name # of hours missed from work #12;RISK MGTDate of Injury Date Time In Time Out Total time worked medical appt no work within restrictions Next Medical Appointment(s): Tuesday of each week. Risk Mgt email: workcomp@colostate.edu; fax
Chopra, Omesh K.; Diercks, Dwight R.; Ma, David Chia-Chiun; Garud, Yogendra S.
2013-12-17
At the request of the United States (U.S.) government, the International Atomic Energy Agency (IAEA) assembled a team of 20 senior safety experts to review the regulatory framework for the safety of operating nuclear power plants in the United States. This review focused on the effectiveness of the regulatory functions implemented by the NRC and on its commitment to nuclear safety and continuous improvement. One suggestion resulting from that review was that the U.S. Nuclear Regulatory Commission (NRC) incorporate lessons learned from periodic safety reviews (PSRs) performed in other countries as an input to the NRC’s assessment processes. In the U.S., commercial nuclear power plants (NPPs) are granted an initial 40-year operating license, which may be renewed for additional 20-year periods, subject to complying with regulatory requirements. The NRC has established a framework through its inspection, and operational experience processes to ensure the safe operation of licensed nuclear facilities on an ongoing basis. In contrast, most other countries do not impose a specific time limit on the operating licenses for NPPs, they instead require that the utility operating the plant perform PSRs, typically at approximately 10-year intervals, to assure continued safe operation until the next assessment. The staff contracted with Argonne National Laboratory (Argonne) to perform a pilot review of selected translated PSR assessment reports and related documentation from foreign nuclear regulatory authorities to identify any potential new regulatory insights regarding license renewal-related topics and NPP operating experience (OpE). A total of 14 PSR assessment documents from 9 countries were reviewed. For all of the countries except France, individual reports were provided for each of the plants reviewed. In the case of France, three reports were provided that reviewed the performance assessment of thirty-four 900-MWe reactors of similar design commissioned between 1978 and 1988. All of the reports reviewed were the regulator’s assessment of the PSR findings rather than the original PSR report, and all but one were English translations from the original language. In these reviews, it was found that most of the countries base their regulatory guidance to some extent (and often to a large extent) on U.S. design codes and standards, NRC regulatory guidance, and U.S. industry guidance. In addition, many of the observed operational technical issues and OpE events reported for U.S. reactors are also cited in the PSR reports. The PSR reports also identified a number of potential technical material/component performance issues and OpE events that are not commonly reported for U.S. plants.
Gevorgyan, T. V. [Institute for Physical Research, National Academy of Sciences, Ashtarak-2, 0203 Ashtarak (Armenia); Shahinyan, A. R. [Yerevan State University, A. Manoogian 1, 0025 Yerevan (Armenia); Kryuchkyan, G. Yu. [Institute for Physical Research, National Academy of Sciences, Ashtarak-2, 0203 Ashtarak (Armenia); Yerevan State University, A. Manoogian 1, 0025 Yerevan (Armenia)
2009-05-15
We show that quantum-interference phenomena can be realized for the dissipative nonlinear systems exhibiting hysteresis-cycle behavior and quantum chaos. Such results are obtained for a driven dissipative nonlinear oscillator with time-dependent parameters and take place for the regimes of long time intervals exceeding dissipation time and for macroscopic levels of oscillatory excitation numbers. Two schemas of time modulation, (i) periodic variation in the strength of the {chi}(3) nonlinearity; (ii) periodic modulation of the amplitude of the driving force, are considered. These effects are obtained within the framework of phase-space quantum distributions. It is demonstrated that the Wigner functions of oscillatory mode in both bistable and chaotic regimes acquire negative values and interference patterns in parts of phase-space due to appropriately time modulation of the oscillatory nonlinear dynamics. It is also shown that the time modulation of the oscillatory parameters essentially improves the degree of sub-Poissonian statistics of excitation numbers.
David Boyd
2004-09-14
A modulation in the V-band with period 527.84+/-1.81 sec and amplitude 0.023 magnitude, attributable to the spin of the magnetic white dwarf primary star, has been detected in 7.5 hours of V-band CCD photometry data recorded during the January 2004 outburst of the DQ Her type dwarf nova DO (YY) Draconis. This measurement is consistent with previous results for the white dwarf spin period based on X-ray and UV observations made with the Hubble Space Telescope, ROSAT and the Rossi X-ray Timing Explorer and appears to be the first independent determination of the spin period in the V-band. It is consistent with previous V-band observations in not showing a significant signal at the first harmonic of the spin period as seen in X-ray and UV data. Light output in the V-band peaks only once per rotation of the white dwarf rather than twice as seen in X-rays and UV. Concurrent observation at optical and X-ray wavelengths is needed to establish whether these two modulation behaviours occur at the same time during the outburst and to investigate the phase relationship between them. A coordinated observing campaign at a future outburst would help to advance our understanding of this system.
Time Domain Partitioning of Electricity Production Cost Simulations
Barrows, C.; Hummon, M.; Jones, W.; Hale, E.
2014-01-01
Production cost models are often used for planning by simulating power system operations over long time horizons. The simulation of a day-ahead energy market can take several weeks to compute. Tractability improvements are often made through model simplifications, such as: reductions in transmission modeling detail, relaxation of commitment variable integrality, reductions in cost modeling detail, etc. One common simplification is to partition the simulation horizon so that weekly or monthly horizons can be simulated in parallel. However, horizon partitions are often executed with overlap periods of arbitrary and sometimes zero length. We calculate the time domain persistence of historical unit commitment decisions to inform time domain partitioning of production cost models. The results are implemented using PLEXOS production cost modeling software in an HPC environment to improve the computation time of simulations while maintaining solution integrity.
Time translation of quantum properties
L. Vanni; R. Laura
2008-12-03
Based on the notion of time translation, we develop a formalism to deal with the logic of quantum properties at different times. In our formalism it is possible to enlarge the usual notion of context to include composed properties involving properties at different times. We compare our results with the theory of consistent histories.
Time machines and quantum theory
Mark J Hadley
2006-12-02
There is a deep structural link between acausal spacetimes and quantum theory. As a consequence quantum theory may resolve some "paradoxes" of time travel. Conversely, non-time-orientable spacetimes naturally give rise to electric charges and spin half. If an explanation of quantum theory is possible, then general relativity with time travel could be it.
Real-time method and apparatus for measuring the decay-time constant of a fluorescing phosphor
Britton, Jr., Charles L. (Alcoa, TN); Beshears, David L. (Knoxville, TN); Simpson, Marc L. (Knoxville, TN); Cates, Michael R. (Oak Ridge, TN); Allison, Steve W. (Knoxville, TN)
1999-01-01
A method for determining the decay-time constant of a fluorescing phosphor is provided, together with an apparatus for performing the method. The apparatus includes a photodetector for detecting light emitted by a phosphor irradiated with an excitation pulse and for converting the detected light into an electrical signal. The apparatus further includes a differentiator for differentiating the electrical signal and a zero-crossing discrimination circuit that outputs a pulse signal having a pulse width corresponding to the time period between the start of the excitation pulse and the time when the differentiated electrical signal reaches zero. The width of the output pulse signal is proportional to the decay-time constant of the phosphor.
2Dimensional localization of acoustic waves in random perturbation of periodic media.
2ÂDimensional localization of acoustic waves in random perturbation of periodic media. Hatem NAJAR to the spectral properties of the relevant selfÂadjoint di#erential operator. As far as the acoustic waves, electromagnetic or acoustic) waves in a periodic meÂ dia perturbed by random impurities. See [7, 8, 9, 10
Guide to Library Resources for English 110 Finding Books, Periodicals, Microforms and Media
Cakoni, Fioralba
the Library of Congress Classification System. Each book (or bound volume of a periodical) is assigned a call1 Guide to Library Resources for English 110 Finding Books, Periodicals, Microforms and Media held by the University of Delaware Library, you may wish to start by searching DELCAT or WorldCat Local
Periodic Cooling of Bird Eggs Reduces Embryonic Growth Efficiency Christopher R. Olson*
Vleck, Carol
927 Periodic Cooling of Bird Eggs Reduces Embryonic Growth Efficiency Christopher R. Olson* Carol M, periodic cooling occurs when the in- cubating adult leaves the nest to forage, but the effects of pe- riodic cooling on embryo growth, yolk use, and metabolism are poorly known. To address this question, we
CONTROLLING ENERGY INTAKE IN THE PREPARTUM PERIOD TO IMPROVE TRANSITION COW HEALTH
Farrell, Anthony P.
CONTROLLING ENERGY INTAKE IN THE PREPARTUM PERIOD TO IMPROVE TRANSITION COW HEALTH by LORI ANN A common feeding practice during the dry period is to switch dairy cows to a low forage, energy dense diet 3 weeks prepartum, but this practice has been criticized as it may lead to the overconsumption
Interrogation of a long-period grating using a mechanically scannable arrayed waveguide grating
Yao, Jianping
); published July 16, 2008 A novel technique to interrogate a long-period grating (LPG) using a mechanically of the LPG is measured. An interrogation system with a resolution of 10 pm at a speed of 10 Hz-period-grating (LPG) sensors have found exten- sive applications ranging from temperature monitor- ing, mechanical
Characterization of LMS and DMR Beamformers in the Presence of Loud Periodic Interferers
George Mason University
Characterization of LMS and DMR Beamformers in the Presence of Loud Periodic Interferers Geoffrey C introduced loud impulsive periodic interferers into these systems. Standard LMS adaptive beamforming interference. 1. INTRODUCTION Adaptive Least Mean-Square (LMS) beamformers are efficient algorithms, providing
Trepanation in South-Central Peru During the Early Late Intermediate Period (ca. AD 10001250)
Cosmides, Leda
Trepanation in South-Central Peru During the Early Late Intermediate Period (ca. AD 1000-two individuals from Andahuaylas, AMS radiocarbon dated to the early Late Intermediate Period (ca. AD 1000 grooving, drilling and boring, and lin- ear cutting were far less successful. Evidence of perioperative
Comparison of quantization of charge transport in periodic and open pumps
Comparison of quantization of charge transport in periodic and open pumps G.M. Graf and G. Ortelli the charges transported in two systems, a spatially periodic and an open quantum pump, both depending physical situations become the same, i.e., that of a large open pump. 1 Introduction In this note we
Transport and Fractionation in Periodic Potential-Energy Landscapes Matthew Pelton and Kosta Ladavac
Grier, David
. Grier Dept. of Physics and Center for Soft Matter Research New York University, New York, NY 10003Transport and Fractionation in Periodic Potential-Energy Landscapes Matthew Pelton and Kosta (Dated: January 2, 2012) Objects driven through periodically modulated potential-energy landscapes in two
Numerical implementation of static Field Dislocation Mechanics theory for periodic media
Acharya, Amit
Numerical implementation of static Field Dislocation Mechanics theory for periodic media R of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, 1206 W. Green St., Urbana, IL investigates the implementation of Field Dislocation Mechanics theory for media with a periodic microstructure
Stable all-optical limiting in nonlinear periodic structures. I. Analysis
Pelinovsky, Dmitry
Stable all-optical limiting in nonlinear periodic structures. I. Analysis Dmitry Pelinovsky consider propagation of coherent light through a nonlinear periodic optical structure consisting of two al-dependent dy- namics. We find the domain for existence of true all-optical limiting when the input
Periodic migration in a physical model of cells on micropatterns Brian A. Camley,1, 2
Li, Bo
Periodic migration in a physical model of cells on micropatterns Brian A. Camley,1, 2 Yanxiang Zhao, bipedal motion, and periodic migration, in which the cell crawls persistently in one direction before-dimensional extracellular ma- trix (ECM). However, cells in ECM often exhibit qualitatively different modes of migration
Predicting short-period, wind-wave-generated seismic1 noise in coastal regions2
Tsai, Victor C.
Predicting short-period, wind-wave-generated seismic1 noise in coastal regions2 Florent Gimberta recorded in this period range is mostly caused by local wind-waves, i.e. by wind-waves occurring within in nearly opposite directions is orders of magnitude smaller than previously suggested for wind-waves, does
Semi-automatic Construction of Cross-period Thesaurus Chaya Liebeskind, Ido Dagan, Jonathan Schler
Wintner, Shuly
Semi-automatic Construction of Cross-period Thesaurus Chaya Liebeskind, Ido Dagan, Jonathan Schler-period (Diachronic) Thesaurus Automatic generation of candidates Research objective Our task: · Support searches of cultural resources · High-quality diachronic thesaurus construction Semi-automatic setting Hardly explored
Emergence of unsteady dark solitary waves from coalescing spatially-periodic patterns
Bridges, Tom
Emergence of unsteady dark solitary waves from coalescing spatially-periodic patterns Thomas J of the defocussing nonlinear Schrödinger equation. In this paper the interest is in a mechanism for the emergence is on the periodic state at innity as the generator. It is shown that a natural mechanism for the emergence
Potsdam Thinkshop Poster Proceedings, p. 4345 Rotational periods of very young brown dwarfs in Cha I
Joergens, Viki
telescope at ESO. We performed aperture photometry and calculated differential magnitudes by means for unevenly spaced data as in our case. The algorithm phase folds the data with a trial period and calculates modulates the total brightness of the star and leads to periodic light vari- Correspondence to: viki@mpe.mpg
Multi-Period Production Capacity Planning for Integrated Product and Production System Design*
Saitou, Kazuhiro "Kazu"
Multi-Period Production Capacity Planning for Integrated Product and Production System Design* Emre.ac.uk kazu@umich.edu .Abstract This paper presents a simulation-based method to aid multi-period production capacity planning by quantifying the trade-off between product quality and production cost. The product
Margaliot, Michael
1 Entrainment to Periodic Initiation and Transition Rates in a Computational Model for Gene, the biological system must entrain or phase-lock to the periodic excitation. Entrainment is also important in synthetic biology. For example, connecting several artificial biological systems that entrain to a common
Sontag, Eduardo
Entrainment to Periodic Initiation and Transition Rates in a Computational Model for Gene to the solar day. In the terminology of systems theory, the biological system must entrain or phase-lock to the periodic excitation. Entrainment is also important in synthetic biology. For example, connecting several
Fejer, Martin M.
June 15, 1996 / Vol. 21, No. 12 / OPTICS LETTERS 857 Photorefractive effects in periodically poled-state photorefractive index perturbations caused by a given optical irradiance distribution in a periodically poled are reduced compared with those in a homogeneously poled crystal by approximately the square of the product
Dusatko, John; Allison, S.; Browne, M.; Krejcik, P.; /SLAC
2012-07-23
The Linac Coherent Light Source requires precision timing trigger signals for various accelerator diagnostics and controls at SLAC-NAL. A new timing system has been developed that meets these requirements. This system is based on COTS hardware with a mixture of custom-designed units. An added challenge has been the requirement that the LCLS Timing System must co-exist and 'know' about the existing SLC Timing System. This paper describes the architecture, construction and performance of the LCLS timing event system.
Setting and Maintaining Arecibo Observatory's Timing Systems
Frequency Standard 14 Time Code Generators TRAK Synchronized Time Code Generator 38 EECO Time Code Generator the time codes if the TRAC Synchronized Time Code Generator fails. Soon the TrueTime time code generator) Time Code Generator TRAK Synchronized Time Code Generator EECO Time Code Generator Transfer standard
A survey for very short-period planets in the Kepler data
Jackson, Brian; Stark, Christopher C.; Chambers, John; Adams, Elisabeth R.; Deming, Drake
2013-12-20
We conducted a search for very short-period transiting objects in the publicly available Kepler data set. Our preliminary survey has revealed four planetary candidates, all with orbital periods less than 12 hr. We have analyzed the data for these candidates using photometric models that include transit light curves, ellipsoidal variations, and secondary eclipses to constrain the candidates' radii, masses, and effective temperatures. Even with masses of only a few Earth masses, the candidates' short periods mean that they may induce stellar radial velocity signals (a few m s{sup –1}) detectable by currently operating facilities. The origins of such short-period planets are unclear, but we discuss the possibility that they may be the remnants of disrupted hot Jupiters. Whatever their origins, if confirmed as planets, these candidates would be among the shortest-period planets ever discovered. Such planets would be particularly amenable to discovery by the planned TESS mission.
S. M. Soskin; O. M. Yevtushenko; R. Mannella
2005-10-12
We show for the first time that a {\\it weak} perturbation in a Hamiltonian system may lead to an arbitrarily {\\it wide} chaotic layer and {\\it fast} chaotic transport. This {\\it generic} effect occurs in any spatially periodic Hamiltonian system subject to a sufficiently slow ac force. We explain it and develop an explicit theory for the layer width, verified in simulations. Chaotic spatial transport as well as applications to the diffusion of particles on surfaces, threshold devices and others are discussed.
Local-time effect on small space-time scale
V. A. Panchelyuga; V. A. Kolombet; M. S. Panchelyuga; S. E. Shnoll
2006-10-18
The paper presents an investigation of local-time effect - one of the manifestations of macroscopic fluctuations phenomena. Was shown the existence of the named effect for longitudinal distance between locations of measurements up to 500 meters. Also a structure of intervals distribution in neighborhood of local-time peak was studied and splitting of the peak was found out. Obtained results lead to conclusion about sharp anisotropy of space-time.
Finding a 60.9-day orbital period for the HMXB 4U 1036-56 with the Swift-BAT monitoring
Cusumano, G; La Parola, V; Masetti, N; D'Aì, A; Tagliaferri, G
2013-01-01
Since November 2004, the Burst Alert Telescope on board Swift is producing a monitoring of the entire sky in the 15-150 keV band, recording the timing and spectral behavior of the detected sources. In this letter we study the properties of the HMXB 4U 1036-56 using both the BAT survey data and those from a Swift-XRT pointed observation. The timing analysis of the BAT light curve unveils a periodic modulation with a period of ~60.9 days, that we explain as the orbital period of the binary system. The position of 4U 1036-56 on the Corbet diagram and the derived semi-major orbit axis (~180 R_dot) are consistent with the Be nature of its companion star. The intensity orbital profile averaged over 88 months of observations shows a large asymmetric shape with a minimum consistent with zero intensity, that could be related to the occultation of the neutron star by the supergiant companion. The source shows also a strong long term variability, going from high intensity states to quiescent states over a time scale of ...
Time Consistent Risk Measure Under Stopping Time Framework ...
2015-02-13
to the stochastic volatility of security markets and constantly change of economic and financial information, the earliest target reaching time is random, it then ...
Ferrocyanide Safety Program. Quarterly report for the period ending March 31, 1994
Meacham, J.E.; Cash, R.J.; Dukelow, G.T.
1994-04-01
Various high-level radioactive waste from defense operations has accumulated at the Hanford Site in underground storage tanks since the mid-1940s. During the 1950s, additional tank storage space was required to support the defense mission. To obtain this additional storage volume within a short time period, and to minimize the need for constructing additional storage tanks, Hanford Site scientists developed a process to scavenge {sup 137}Cs from tank waste liquids. In implementing this process, approximately 140 metric tons of ferrocyanide were added to waste that was later routed to some Hanford Site single-shell tanks. The reactive nature of ferrocyanide in the presence of an oxidizer has been known for decades, but the conditions under which the compound can undergo endothermic and exothermic reactions have not been thoroughly studied. Because the scavenging process precipitated ferrocyanide from solutions containing nitrate and nitrite, an intimate mixture of ferrocyanides and nitrates and/or nitrites is likely to exist in some regions of the ferrocyanide tanks. This quarterly report provides a status of the activities underway at the Hanford Site on the Ferrocyanide Safety Issue, as requested by the Defense Nuclear Facilities Safety Board (DNFSB) in their Recommendation 90-7. A revised Ferrocyanide Safety Program Plan addressing the total Ferrocyanide Safety Program, including the six parts of DNFSB Recommendation 90-7, was recently prepared and released in March 1994. Activities in the revised program plan are underway or have been completed, and the status of each is described in Section 4.0 of this report.
Rothe, R.E.
1996-09-30
A series of 62 critical and critical approach experiments were performed to evaluate a possible novel means of storing large volumes of fissile solution in a critically safe configuration. This study is intended to increase safety and economy through use of such a system in commercial plants which handle fissionable materials in liquid form. The fissile solution`s concentration may equal or slightly exceed the minimum-critical-volume concentration; and experiments were performed for high-enriched uranium solution. Results should be generally applicable in a wide variety of plant situations. The method is called the `Poisoned Tube Tank` because strong neutron absorbers (neutron poisons) are placed inside periodically spaced stainless steel tubes which separate absorber material from solution, keeping the former free of contamination. Eight absorbers are investigated. Both square and triangular pitched lattice patterns are studied. Ancillary topics which closely model typical plant situations are also reported. They include the effect of removing small bundles of absorbers as might occur during inspections in a production plant. Not taking the tank out of service for these inspections would be an economic advantage. Another ancillary topic studies the effect of the presence of a significant volume of unpoisoned solution close to the Poisoned Tube Tank on the critical height. A summary of the experimental findings is that boron compounds were excellent absorbers, as expected. This was true for granular materials such as Gerstley Borate and Borax; but it was also true for the flexible solid composed of boron carbide and rubber, even though only thin sheets were used. Experiments with small bundles of absorbers intentionally removed reveal that quite reasonable tanks could be constructed that would allow a few tubes at a time to be removed from the tank for inspection without removing the tank from production service.
George F R Ellis
2008-12-01
Current theoretical physics suggests the flow of time is an illusion: the entire universe just is, with no special meaning attached to the present time. This paper points out that this view, in essence represented by usual space-time diagrams, is based on time-reversible microphysical laws, which fail to capture essential features of the time-irreversible nature of decoherence and the quantum measurement process, as well as macro-physical behaviour and the development of emergent complex systems, including life, which exist in the real universe. When these are taken into account, the unchanging block universe view of spacetime is best replaced by an evolving block universe which extends as time evolves, with the potential of the future continually becoming the certainty of the past; spacetime itself evolves, as do the entities within it. However this time evolution is not related to any preferred surfaces in spacetime; rather it is associated with the evolution of proper time along families of world lines. The default state of fundamental physics should not be taken to be a time irreversible evolution of physical states: it is an ongoing irreversible development of time itself.
Aagaard, B T; Graves, R W; Rodgers, A; Brocher, T M; Simpson, R W; Dreger, D; Petersson, N A; Larsen, S C; Ma, S; Jachens, R C
2009-11-04
We simulate long-period (T > 1.0-2.0 s) and broadband (T > 0.1 s) ground motions for 39 scenarios earthquakes (Mw 6.7-7.2) involving the Hayward, Calaveras, and Rodgers Creek faults. For rupture on the Hayward fault we consider the effects of creep on coseismic slip using two different approaches, both of which reduce the ground motions compared with neglecting the influence of creep. Nevertheless, the scenario earthquakes generate strong shaking throughout the San Francisco Bay area with about 50% of the urban area experiencing MMI VII or greater for the magnitude 7.0 scenario events. Long-period simulations of the 2007 Mw 4.18 Oakland and 2007 Mw 4.5 Alum Rock earthquakes show that the USGS Bay Area Velocity Model version 08.3.0 permits simulation of the amplitude and duration of shaking throughout the San Francisco Bay area, with the greatest accuracy in the Santa Clara Valley (San Jose area). The ground motions exhibit a strong sensitivity to the rupture length (or magnitude), hypocenter (or rupture directivity), and slip distribution. The ground motions display a much weaker sensitivity to the rise time and rupture speed. Peak velocities, peak accelerations, and spectral accelerations from the synthetic broadband ground motions are, on average, slightly higher than the Next Generation Attenuation (NGA) ground-motion prediction equations. We attribute at least some of this difference to the relatively narrow width of the Hayward fault ruptures. The simulations suggest that the Spudich and Chiou (2008) directivity corrections to the NGA relations could be improved by including a dependence on the rupture speed and increasing the areal extent of rupture directivity with period. The simulations also indicate that the NGA relations may under-predict amplification in shallow sedimentary basins.
Name:______________ Period:_____________
Lega, Joceline
cup to balance the system again. Fill in the following table for when the system is balanced: Plot on the line and finding the ratio (expressed as a fraction) of the change in the y- coordinates to the change in the x- coordinates. slope= rise run = y2-y1 x2-x1 6: Label two points in the line and fill
Klotz, David
2015-01-01
the Great, Persia invaded Egypt twice and administered it asEl- Qeis) in Upper Egypt (BM 37496; Yoyotte 1972b: pl. 19a;sites are on the fringes of Egypt: Kharga Oasis to the west,
Williamson, Jacquelyn
2015-01-01
The city of Akhenaten I. London: Egypt Exploration Society.of Akhenaten III. London: Egypt Exploration Society. Petrie,the American Research Center in Egypt 25, pp. 117-121. 1991
Formation of laser-induced periodic surface structures on niobium by femtosecond laser irradiation
Pan, A.; Dias, A.; Gomez-Aranzadi, M.; Olaizola, S. M. [CIC microGUNE, Goiru Kalea 9 Polo Innovación Garaia, 20500 Arrasate-Mondragón (Spain); CEIT-IK4 and Tecnun, University of Navarra, Manuel Lardizábal 15, 20018 San Sebastián (Spain); Rodriguez, A. [CIC microGUNE, Goiru Kalea 9 Polo Innovación Garaia, 20500 Arrasate-Mondragón (Spain)
2014-05-07
The surface morphology of a Niobium sample, irradiated in air by a femtosecond laser with a wavelength of 800?nm and pulse duration of 100 fs, was examined. The period of the micro/nanostructures, parallel and perpendicularly oriented to the linearly polarized fs-laser beam, was studied by means of 2D Fast Fourier Transform analysis. The observed Laser-Induced Periodic Surface Structures (LIPSS) were classified as Low Spatial Frequency LIPSS (periods about 600?nm) and High Spatial Frequency LIPSS, showing a periodicity around 300?nm, both of them perpendicularly oriented to the polarization of the incident laser wave. Moreover, parallel high spatial frequency LIPSS were observed with periods around 100?nm located at the peripheral areas of the laser fingerprint and overwritten on the perpendicular periodic gratings. The results indicate that this method of micro/nanostructuring allows controlling the Niobium grating period by the number of pulses applied, so the scan speed and not the fluence is the key parameter of control. A discussion on the mechanism of the surface topology evolution was also introduced.
The Lyapunov function for Schrödinger operators with a periodic 2x2 matrix potential
Andrei Badanin; Jochen Brüning; Evgeny Korotyaev
2005-08-29
We consider the Schr\\"odinger operator on the real line with a 2x2 matrix valued 1-periodic potential. The spectrum of this operator is absolutely continuous and consists of intervals separated by gaps. We define a Lyapunov function which is analytic on a two sheeted Riemann surface. On each sheet, the Lyapunov function has the same properties as in the scalar case, but it has branch points, which we call resonances. We prove the existence of real as well as non-real resonances for specific potentials. We determine the asymptotics of the periodic and anti-periodic spectrum and of the resonances at high energy. We show that there exist two type of gaps: 1) stable gaps, where the endpoints are periodic and anti-periodic eigenvalues, 2) unstable (resonance) gaps, where the endpoints are resonances (i.e., real branch points of the Lyapunov function). We also show that periodic and anti-periodic spectrum together determine the spectrum of the matrix Hill operator.
Waszczak, Adam; Ofek, Eran O; Laher, Russ; Masci, Frank; Levitan, David; Surace, Jason; Cheng, Yu-Chi; Ip, Wing-Huen; Kinoshita, Daisuke; Helou, George; Prince, Thomas A; Kulkarni, Shrinivas
2015-01-01
We fit 54,296 sparsely-sampled asteroid lightcurves in the Palomar Transient Factory to a combined rotation plus phase-function model. Each lightcurve consists of 20+ observations acquired in a single opposition. Using 805 asteroids in our sample that have reference periods in the literature, we find the reliability of our fitted periods is a complicated function of the period, amplitude, apparent magnitude and other attributes. Using the 805-asteroid ground-truth sample, we train an automated classifier to estimate (along with manual inspection) the validity of the remaining 53,000 fitted periods. By this method we find 9,033 of our lightcurves (of 8,300 unique asteroids) have reliable periods. Subsequent consideration of asteroids with multiple lightcurve fits indicate 4% contamination in these reliable periods. For 3,902 lightcurves with sufficient phase-angle coverage and either a reliably-fit period or low amplitude, we examine the distribution of several phase-function parameters, none of which are bimo...
Timing analysis for 20 millisecond pulsars in the Parkes Pulsar Timing Array
Reardon, D J; Coles, W; Levin, Y; Keith, M J; Bailes, M; Bhat, N D R; Burke-Spolaor, S; Dai, S; Kerr, M; Lasky, P D; Manchester, R N; Os?owski, S; Ravi, V; Shannon, R M; van Straten, W; Toomey, L; Wang, J; Wen, L; You, X P; Zhu, X -J
2015-01-01
We present timing models for 20 millisecond pulsars in the Parkes Pulsar Timing Array. The precision of the parameter measurements in these models has been improved over earlier results by using longer data sets and modelling the non-stationary noise. We describe a new noise modelling procedure and demonstrate its effectiveness using simulated data. Our methodology includes the addition of annual dispersion measure (DM) variations to the timing models of some pulsars. We present the first significant parallax measurements for PSRs J1024-0719, J1045-4509, J1600-3053, J1603-7202, and J1730-2304, as well as the first significant measurements of some post-Keplerian orbital parameters in six binary pulsars, caused by kinematic effects. Improved Shapiro delay measurements have resulted in much improved pulsar mass measurements, particularly for PSRs J0437-4715 and J1909-3744 with $M_p=1.44\\pm0.07$ $M_\\odot$ and $M_p=1.47\\pm0.03$ $M_\\odot$ respectively. The improved orbital period-derivative measurement for PSR J043...
Olaf Dreyer
2009-04-22
Attempts to quantize general relativity encounter an odd problem. The Hamiltonian that normally generates time evolution vanishes in the case of general relativity as a result of diffeomorphism invariance. The theory seems to be saying that time does not exist. The most obvious feature of our world, namely that time seems to progress and that the world changes accordingly becomes a problem in this presumably fundamental theory. This is called the problem of time. In this essay we argue that this problem is the result of an unphysical idealization. We are caught in this "problem of time" trap because we took a wrong turn in the early days of relativity by permanently including a split of geometry and matter into our physical theories. We show that another possibility exists that circumvents the problem of time and also sheds new light on other problems like the cosmological constant problem and the horizon problem in early universe cosmology.
Kelkar, N. G.
2010-06-15
The lifetime of an unstable state or resonance formed as an intermediate state in two-body scattering is known to be related to the dwell time or the time spent within a given region of space by the two interacting particles. This concept is extended to the case of three-body systems and a relation connecting the three-body dwell time with the two-body dwell times of the substructures of the three-body system is derived for the case of separable wave functions. The Kapur-Peierls formalism is revisited to discover one of the first definitions of dwell time in the literature. An extension of the Kapur-Peierls formalism to the three-body case shows that the lifetime of a three-body resonance can indeed be given by the three-body dwell time.
Reactor control rod timing system
Wu, Peter T. K. (Clifton Park, NY)
1982-01-01
A fluid driven jet-edge whistle timing system for control rods of a nuclear reactor for producing real-time detection of the timing of each control rod in its scram operation. An important parameter in reactor safety, particularly for liquid metal fast breeder reactors (LMFBR), is the time deviation between the time the control rod is released and the time the rod actually reaches the down position. The whistle has a nearly pure tone signal with center frequency (above 100 kHz) far above the frequency band in which the energy of the background noise is concentrated. Each control rod can be fitted with a whistle with a different frequency so that there is no ambiguity in differentiating the signal from each control rod.
Reactor control rod timing system
Wu, P.T.
1982-02-09
A fluid driven jet-edge whistle timing system for control rods of a nuclear reactor for producing real-time detection of the timing of each control rod in its scram operation. An important parameter in reactor safety, particularly for liquid metal fast breeder reactors (LMFBR), is the time deviation between the time the control rod is released and the time the rod actually reaches the down position. The whistle has a nearly pure tone signal with center frequency (Above 100 kHz) far above the frequency band in which the energy of the background noise is concentrated. Each control rod can be fitted with a whistle with a different frequency so that there is no ambiguity in differentiating the signal from each control rod.
Commencement Ceremony Department Time Location Department and Major Time Location
Kaji, Hajime
Engineering 15:30 Bldg. 63 Classroom 01 (2nd Fl.) Industrial and Management Systems Engineering 15:30 Bldg. 63 and Management 15:30 Bldg. 63 Classroom 01 (2nd Fl.) Department Time Location Department and Major Time Location:30 Bldg. 57 202 Modern Mechanical Engineering 10:30 Bldg. 57 202 Industrial and Management Systems
49 Stress-timed vs. Syllable-timed Languages
Mehler, Jacques
49 Stress-timed vs. Syllable- timed Languages Marina Nespor Mohinish Shukla Jacques Mehler 1; Prince 1983; Nespor & Vogel 1989; chapter 43: representations of word stress), the element that "establishes order" in the flow of speech is stress: universally, stressed and unstressed positions alternate
Time Structure of Muonic Showers
L. Cazon; R. A. Vazquez; A. A. Watson; E. Zas
2003-11-10
An analytical description of the time structure of the pulses induced by muons in air showers at ground level is deduced assuming the production distance distribution for the muons can be obtained elsewhere. The results of this description are compared against those obtained from simulated showers using AIRES. Major contributions to muon time delays are identified and a relation between the time structure and the depth distribution is unveiled.
Semi-classical formula beyond the Ehrenfest time in quantum chaos. (I) Trace formula
Frederic Faure
2007-03-19
We consider a nonlinear area preserving Anosov map M on the torus phase space, which is the simplest example of a fully chaotic dynamics. We are interested in the quantum dynamics for long time, generated by the unitary quantum propagator Mq. The usual semi-classical Trace formula expresses Tr(Mq^t) for finite time t, in the limit hbar->0, in terms of periodic orbits of M of period t. Recent work reach time t<< tE/6 where tE=log(1/hbar)/lambda is the Ehrenfest time, and lambda is the Lyapounov coefficient. Using a semi-classical normal form description of the dynamics uniformly over phase space, we show how to extend the trace formula for longer time of the form t= C.tE where C is any constant, with an arbitrary small error.
Seismic velocity estimation from time migration
Cameron, Maria Kourkina
2007-01-01
v List of Tables Comparison of time migration and depthof seismic imaging: time migration and depth migration. TimeComparison of time migration and depth migration Adequate
Time and maps Menno-Jan Kraak Time and maps ! Â· Why interested in time? Â· What is time and Â· How is time perceived? Â· How is time represented? Why interested in time? GIScience perspective) - analysis of changes over time - analysis of patterns of change over time ! Â· Development of methods
Quantum gravity, the origin of time and time's arrow
Moffat, J.W. (Univ. of Toronto, Ontario (Canada))
1993-03-01
The local Lorentz and diffeomorphism symmetries of Einstein's gravitational theory are spontaneously broken by a Higgs mechanism by invoking a phase transition in the early universe, at a critical temperature [Tc] below which the symmetry is restored. The spontaneous breakdown of the vacuum state generates an external time, and the wave function of the universe satisfies a time-dependent Schroedinger equation, which reduces to the Wheeler-deWitt equation in the classical regime for T<[Tc], allowing a semiclassical WKB approximation to the wave function. The conservation of energy is spontaneously violated for T>[Tc], and matter is created fractions of seconds after the big bang, generating the matter in the Universe. The time direction of the vacuum expectation value of the scalar Higgs field generates a time asymmetry, which defines the cosmological arrow of time and the direction of increasing entropy as the Lorentz symmetry is restored at low temperatures. 52 refs.
SHORT-PERIOD g-MODE PULSATIONS IN LOW-MASS WHITE DWARFS TRIGGERED BY H-SHELL BURNING
Córsico, A. H.; Althaus, L. G.
2014-09-20
The detection of pulsations in white dwarfs with low mass offers the possibility of probing their internal structures through asteroseismology and placing constraints on the binary evolutionary processes involved in their formation. In this Letter, we assess the impact of stable H burning on the pulsational stability properties of low-mass He-core white dwarf models resulting from binary star evolutionary calculations. We found that besides a dense spectrum of unstable radial modes and nonradial g and p modes driven by the ? mechanism due to the partial ionization of H in the stellar envelope, some unstable g modes with short pulsation periods are also powered by H burning via the ? mechanism of mode driving. This is the first time that ? destabilized modes are found in models representative of cool white dwarf stars. The short periods recently detected in the pulsating low-mass white dwarf SDSS J111215.82+111745.0 could constitute the first evidence of the existence of stable H burning in these stars, in particular in the so-called extremely low-mass white dwarfs.
The 5 hr pulse period and broadband spectrum of the Symbiotic X-ray Binary 3A 1954+319
Marcu, Diana M; Pottschmidt, Katja; Grinberg, Victoria; Mueller, Sebastian; Wilms, Joern; Postnov, Konstantin A; Corbet, Robin H D; Markwardt, Craig B; Bel, Marion Cadolle; 10.1088/2041-8205/742/1/L11
2011-01-01
We present an analysis of the highly variable accreting X-ray pulsar 3A 1954+319 using 2005-2009 monitoring data obtained with INTEGRAL and Swift. This considerably extends the pulse period history and covers flaring episodes in 2005 and 2008. In 2006 the source was identified as one of only a few known symbiotic X-ray binaries (SyXBs), i.e., systems composed of a neutron star accreting from the inhomogeneous medium around an M-giant star. The extremely long pulse period of 5.3 hr is directly visible in the 2008 INTEGRAL-ISGRI outburst light curve. The pulse profile is double peaked and generally not significantly energy dependent although there is an indication of possible softening during the main pulse. During the outburst a strong spin-up of -1.8 10^(-4) hr hr^(-1) occurred. Between 2005 and 2008 a long-term spin-down trend of 2.1 10^-5 hr hr^(-1) was observed for the first time for this source. The 3-80 keV pulse peak spectrum of 3A 1954+319 during the 2008 flare could be well described by a thermal Comp...
Smith, Ken
2007-11-26
This report describes earthquake activity within approximately 65 km of Yucca Mountain site during the October 1, 2004 to September 30, 2006 time period (FY05-06). The FY05-06 earthquake activity will be compared with the historical and more recent period of seismic activity in the Yucca Mountain region. The relationship between the distribution of seismicity and active faults, historical patterns of activity, and rates of earthquakes (number of events and their magnitudes) are important components in the assessment of the seismic hazard for the Yucca Mountain site. Since October 1992 the University of Nevada has compiled a catalog of earthquakes in the Yucca Mountain area. Seismicity reports have identified notable earthquake activity, provided interpretations of the seismotectonics of the region, and documented changes in the character of earthquake activity based on nearly 30 years of site-characterization monitoring. Data from stations in the seismic network in the vicinity of Yucca Mountain is collected and managed at the Nevada Seismological Laboratory (NSL) at the University of Nevada Reno (UNR). Earthquake events are systematically identified and cataloged under Implementing Procedures developed in compliance with the Nevada System of Higher Education (NSHE) Quality Assurance Program. The earthquake catalog for FY05-06 in the Yucca Mountain region submitted to the Yucca Mountain Technical Data Management System (TDMS) forms the basis of this report.
Bonnet-Bidaud, J M; Busschaert, C; Falize, E; Michaut, C
2015-01-01
Quasi-periodic oscillations (QPOs) are observed in the optical flux of some polars with typical periods of 1 to 3 s but none have been observed yet in X-rays where a significant part of the accreting energy is released. QPOs are expected and predicted from shock oscillations. Most of the polars have been observed by the XMM-Newton satellite. We made use of the homogeneous set of observations of the polars by XMM-Newton to search for the presence of QPOs in the (0.5-10 keV) energy range and to set significant upper limits for the brightest X-ray polars. We extracted high time-resolution X-ray light curves by taking advantage of the 0.07 sec resolution of the EPIC-PN camera. Among the 65 polars observed with XMM-Newton from 1998 to 2012, a sample of 24 sources was selected on the basis of their counting rate in the PN instrument to secure significant limits. We searched for QPOs using Fast Fourier Transform (FFT) methods and defined limits of detection using statistical tools. Among the sample surveyed, none sh...
A. Chakrabarti
1998-01-05
An iterative map of the unit disc in the complex plane (Appendix) is used to explore certain aspects of selfdual, four dimensional gauge fields (quasi)periodic in the Euclidean time. These fields are characterized by two topological numbers and contain standard instantons and monopoles as different limits. The iterations do not correspond directly to a discretized time evolution of the gauge fields. They are implemented in an indirect fashion. First, (t,r,\\theta,\\phi) being the standard coordinates, the (r,t) half plane is mapped on the unit disc in an appropriate way. This provides an (r,t) parametrization (Sec.1) of Z_0, the starting point of the iterations and makes the iterates increasingly complex functions of r and t. These are then incorporated as building blocks in the generating function of the fields (Sec.2). We explain (starting in Sec.1 and at different stages) in what sense and to what extent some remarkable features of our map (indicated in the title) are thus carried over into the continuous time development of the fields. Special features for quasiperiodicity are studied (Sec.3). Spinor solutions (Sec.4) and propagators (Sec.5) are discussed from the point of view of the mapping. Several possible generalizations are indicated (Sec.6). Some broader topics are discussd in conclusion (Sec.7).
Hot Jupiter Breezes: Time-dependent Outflows from Extrasolar Planets
Owen, James E
2015-01-01
We explore the dynamics of magnetically controlled outflows from Hot Jupiters, where these flows are driven by UV heating from the central star. In these systems, some of the open field lines do not allow the flow to pass smoothly through the sonic point, so that steady-state solutions do not exist in general. This paper focuses on this type of magnetic field configuration, where the resulting flow becomes manifestly time-dependent. We consider the case of both steady heating and time-variable heating, and find the time scales for the corresponding time variations of the outflow. Because the flow cannot pass through the sonic transition, it remains subsonic and leads to so-called breeze solutions. One manifestation of the time variability is that the flow samples a collection of different breeze solutions over time, and the mass outflow rate varies in quasi-periodic fashion. Because the flow is subsonic, information can propagate inward from the outer boundary, which determines, in part, the time scale of the...