Parallel time integration software
2014-07-01
This package implements an optimal-scaling multigrid solver for the (non) linear systems that arise from the discretization of problems with evolutionary behavior. Typically, solution algorithms for evolution equations are based on a time-marching approach, solving sequentially for one time step after the other. Parallelism in these traditional time-integrarion techniques is limited to spatial parallelism. However, current trends in computer architectures are leading twards system with more, but not faster. processors. Therefore, faster compute speeds mustmore » come from greater parallelism. One approach to achieve parallelism in time is with multigrid, but extending classical multigrid methods for elliptic poerators to this setting is a significant achievement. In this software, we implement a non-intrusive, optimal-scaling time-parallel method based on multigrid reduction techniques. The examples in the package demonstrate optimality of our multigrid-reduction-in-time algorithm (MGRIT) for solving a variety of parabolic equations in two and three sparial dimensions. These examples can also be used to show that MGRIT can achieve significant speedup in comparison to sequential time marching on modern architectures.« less
Parallel time integration software
2014-07-01
This package implements an optimal-scaling multigrid solver for the (non) linear systems that arise from the discretization of problems with evolutionary behavior. Typically, solution algorithms for evolution equations are based on a time-marching approach, solving sequentially for one time step after the other. Parallelism in these traditional time-integrarion techniques is limited to spatial parallelism. However, current trends in computer architectures are leading twards system with more, but not faster. processors. Therefore, faster compute speeds must come from greater parallelism. One approach to achieve parallelism in time is with multigrid, but extending classical multigrid methods for elliptic poerators to this setting is a significant achievement. In this software, we implement a non-intrusive, optimal-scaling time-parallel method based on multigrid reduction techniques. The examples in the package demonstrate optimality of our multigrid-reduction-in-time algorithm (MGRIT) for solving a variety of parabolic equations in two and three sparial dimensions. These examples can also be used to show that MGRIT can achieve significant speedup in comparison to sequential time marching on modern architectures.
Multimodal integration of time.
Bausenhart, Karin M; de la Rosa, Maria Dolores; Ulrich, Rolf
2014-01-01
Recent studies suggest that the accuracy of duration discrimination for visually presented intervals is strongly impaired by concurrently presented auditory intervals of different duration, but not vice versa. Because these studies rely mostly on accuracy measures, it remains unclear whether this impairment results from changes in perceived duration or rather from a decrease in perceptual sensitivity. We therefore assessed complete psychometric functions in a duration discrimination task to disentangle effects on perceived duration and sensitivity. Specifically, participants compared two empty intervals marked by either visual or auditory pulses. These pulses were either presented unimodally, or accompanied by task-irrelevant pulses in the respective other modality, which defined conflicting intervals of identical, shorter, or longer duration. Participants were instructed to base their temporal judgments solely on the task-relevant modality. Despite this instruction, perceived duration was clearly biased toward the duration of the intervals marked in the task-irrelevant modality. This was not only found for the discrimination of visual intervals, but also, to a lesser extent, for the discrimination of auditory intervals. Discrimination sensitivity, however, was similar between all multimodal conditions, and only improved compared to the presentation of unimodal visual intervals. In a second experiment, evidence for multisensory integration was even found when the task-irrelevant modality did not contain any duration information, thus excluding noncompliant attention allocation as a basis of our results. Our results thus suggest that audiovisual integration of temporally discrepant signals does not impair discrimination sensitivity but rather alters perceived duration, presumably by means of a temporal ventriloquism effect. PMID:24351985
NASA Astrophysics Data System (ADS)
Soloviev, A. A.; Agayan, S. M.; Gvishiani, A. D.; Bogoutdinov, Sh. R.; Chulliat, A.
2012-05-01
Preliminary magnetograms contain different types of temporal anthropogenic disturbances: spikes, baseline jumps, drifts, etc. These disturbances should be identified and filtered out during the preprocessing of the preliminary records for the definitive data. As of now, at the geomagnetic observatories, such filtering is carried out manually. Most of the disturbances in the records sampled every second are spikes, which are much more abundant than those on the magnetograms sampled every minute. Another important feature of the 1-s magnetograms is the presence of a plenty of specific disturbances caused by short-period geomagnetic pulsations, which must be retained in the definitive records. Thus, creating an instrument for formalized and unified recognition of spikes on the preliminary 1-s magnetograms would largely solve the problem of labor-consuming manual preprocessing of the magnetic records. In the context of this idea, in the present paper, we focus on recognition of the spikes on the 1-s magnetograms as a key point of the problem. We describe here the new algorithm of pattern recognition, SPs, which is capable of automatically identifying the spikes on the 1-s magnetograms with a low probability of missed events and false alarms. The algorithm was verified on the real magnetic data recorded at the French observatory located on Easter Island in the Pacific.
Time-dependent multiphoton ionization from the He 1s2s ? metastable state
NASA Astrophysics Data System (ADS)
Nicolaides, Cleanthes A.; Dionissopoulou, Stavroula; Mercouris, Theodoros
1996-01-01
Using the state-specific expansion approach to the solution of the time-dependent Schrödinger equation, we calculated a number of observables from the response of the He 0953-4075/29/2/012/img2 metastable state to strong as well as to weak laser pulses. The photon energies (0953-4075/29/2/012/img3) were 1 eV, 2 eV, 2.47 eV and 3 eV, and the intensities (I) covered the range from 0953-4075/29/2/012/img4 to 0953-4075/29/2/012/img5. For the weak intensities, the results are in full accord with the experimental findings of Haberland and co-workers. For the strong intensities, our predictions are of quantitative as well as of qualitative value. They permit conclusions about the fingerprints left on observable spectra by electron correlation, by Rydberg levels and by doubly excited states and about the extent to which high harmonics of short wavelength can be produced as a function of I and 0953-4075/29/2/012/img6 when the initial state lies above the ground state. Finally, we argue that calculations of harmonic spectra based on the use of the acceleration form of the dipole operator will produce, in general, unreliable results even when some correlations are accounted for.
Optimal integration time in OCT imaging
NASA Astrophysics Data System (ADS)
Martin, Lorenz; Gräub, Stephan; Meier, Christoph
2015-07-01
When measuring static objects with 3D OCT, two opposing trends occur: If the integration time is too short, the measurement is noisy resulting in granulated textures on measured objects. If the integration time is too long, drifts e.g. due to thermal effects or unstable laser sources lead to blurred images. The Allan variance is a scheme to find the optimal integration time in terms of reducing noise without picking up signal drift. A long-term measurement with short integration time of a reference target under realistic conditions is needed to obtain the database for the calculation of the Allan variance. Longer integration times are simulated by taking averages of subsequent samples. The Allan variance being the mean of the squared differences between two consecutive averages is calculated for different integration times. The optimal integration time is achieved for minimal Allan variance. First, the scheme is explained and discussed with simulated data. Then, reference measurements of layers of adhesive tape made with a 3D OCT device are analysed to find the optimal integration time of the device. Finally, the findings are applied to the detection of water inclusions in calcite. With too short integration time the water inclusions appear with a stained surface. With the integration time increased towards the optimal time, the surfaces of the water inclusions get smoother and easier to discriminate from the background. Ready-to-use Octave code for the computation of the Allan variance is provided.
NASA Technical Reports Server (NTRS)
Straton, Jack C.
1989-01-01
The class of integrals containing the product of N 1s hydrogenic orbitals and M Coulomb or Yukawa potentials with m plane waves is investigated analytically. The results obtained by Straton (1989) are extended and generalized. It is shown that the dimensionality of the entire class can be reduced from 3m to M+N-1.
Integrating Time, Place, and Play
ERIC Educational Resources Information Center
Gallavan, Nancy P.
2004-01-01
"Time, Place, and Play," is a short phrase, but is summarizes three very big concepts--history, geography, and culture--that are part of the elementary social studies curriculum. This article relates the story of how twenty-five elementary and middle school teachers, meeting over several weeks in a university class, designed a unit of study on the…
Feature integration across space, time, and orientation
Otto, Thomas U.; Öğmen, Haluk; Herzog, Michael H.
2012-01-01
The perception of a visual target can be strongly influenced by flanking stimuli. In static displays, performance on the target improves when the distance to the flanking elements increases- proposedly because feature pooling and integration vanishes with distance. Here, we studied feature integration with dynamic stimuli. We show that features of single elements presented within a continuous motion stream are integrated largely independent of spatial distance (and orientation). Hence, space based models of feature integration cannot be extended to dynamic stimuli. We suggest that feature integration is guided by perceptual grouping operations that maintain the identity of perceptual objects over space and time. PMID:19968428
Local-time representation of path integrals
NASA Astrophysics Data System (ADS)
Jizba, Petr; Zatloukal, Václav
2015-12-01
We derive a local-time path-integral representation for a generic one-dimensional time-independent system. In particular, we show how to rephrase the matrix elements of the Bloch density matrix as a path integral over x -dependent local-time profiles. The latter quantify the time that the sample paths x (t ) in the Feynman path integral spend in the vicinity of an arbitrary point x . Generalization of the local-time representation that includes arbitrary functionals of the local time is also provided. We argue that the results obtained represent a powerful alternative to the traditional Feynman-Kac formula, particularly in the high- and low-temperature regimes. To illustrate this point, we apply our local-time representation to analyze the asymptotic behavior of the Bloch density matrix at low temperatures. Further salient issues, such as connections with the Sturm-Liouville theory and the Rayleigh-Ritz variational principle, are also discussed.
Efficient time integration in dislocation dynamics
NASA Astrophysics Data System (ADS)
Sills, Ryan B.; Cai, Wei
2014-03-01
The efficiencies of one implicit and three explicit time integrators have been compared in line dislocation dynamics simulations using two test cases: a collapsing loop and a Frank-Read (FR) source with a jog. The time-step size and computational efficiency of the explicit integrators is shown to become severely limited due to the presence of so-called stiff modes, which include the oscillatory zig-zag motion of discretization nodes and orientation fluctuations of the jog. In the stability-limited regime dictated by these stiff modes, the implicit integrator shows superior efficiency when using a Jacobian that only accounts for short-range interactions due to elasticity and line tension. However, when a stable dislocation dipole forms during a jogged FR source simulation, even the implicit integrator suffers a substantial drop in the time-step size. To restore computational efficiency, a time-step subcycling algorithm is tested, in which the nodes involved in the dipole are integrated over multiple smaller, local time steps, while the remaining nodes take a single larger, global time step. The time-step subcycling method leads to substantial efficiency gain when combined with either an implicit or an explicit integrator.
Demonstration of a time-integrating microdosimeter
NASA Astrophysics Data System (ADS)
Famiano, M. A.; Hamby, D. M.
1997-02-01
A tissue-equivalent spherical proportional counter is used with a modified amplifier system to measure specific energy deposited from a uniform radiation field for short periods of time (on the order of microseconds to milliseconds) in order to extrapolate to dose in sub-micron tissue volumes. The signal is integrated over a variable collection time which is adjusted with a square-wave pulse. Charge from partical passages is collected on the anode during the period in which the integrator is triggered, and the signal decays quickly to zero after the integrator feedback switch resets; the process repeats for every "triggering" pulse. Measurements of energy deposited from X-rays are examined. Spectral characteristics as a function of charge collection time are observed and frequency plots of specific energy and collection time-interval are presented.
Multirate Time Integration for Compressible Atmospheric Flow
NASA Astrophysics Data System (ADS)
Wensch, Jörg; Knoth, Oswald; Galant, Alexander
2008-09-01
We generalise split-explicit Runge-Kutta methods utilised in atmospheric dynamics simulation where fast sub-processes (sound waves) are integrated by small time steps. The inclusion of fixed tendencies of previous stages leads to an improvement of the stability barrier for the acoustics equation by a factor of two. Order and stability analysis is based on the assumption of exact integration of fast subprocesses.
NASA Astrophysics Data System (ADS)
Negri, Alessandra; Morigi, Caterina; Sangiorgi, Francesca; Keller, Joerg
2016-04-01
The Eastern Mediterranean late Neogene to Quaternary sedimentary record is characterized by the widespread and distinctly periodical occurrence of organic carbon-rich layers, called sapropels. The deposition of sapropels is related to significant changes in climate, in the pattern of water circulation and in the biogeochemical cycles. The primary cause triggering the formation of sapropels has been debated ever since their discovery: productivity in the surface waters and organic matter preservation at the sea-floor due to hypoxia or anoxia have been indicated as the two major contributing factors operating either separately or combined. Moreover, each sapropel seems to have its own peculiar feature, likely attributed to the different climate forcing and the different response of productivity and preservation to the water column parameters. Here we present preliminary data from core M25/4 12, located in the Ionian Sea, containing a continuous record of the sapropels deposited in the last 330 ka (S1 to S10, excluding S2). We analysed the microfossil assemblages in sapropels S1 (10 ka BP), S3 (80 ka BP) and S5 (125 ka BP) at a multi-centennial time resolution to get insights into the climatic and oceanographical features leading to their deposition and the role of productivity and preservation.
Local-time representation of path integrals.
Jizba, Petr; Zatloukal, Václav
2015-12-01
We derive a local-time path-integral representation for a generic one-dimensional time-independent system. In particular, we show how to rephrase the matrix elements of the Bloch density matrix as a path integral over x-dependent local-time profiles. The latter quantify the time that the sample paths x(t) in the Feynman path integral spend in the vicinity of an arbitrary point x. Generalization of the local-time representation that includes arbitrary functionals of the local time is also provided. We argue that the results obtained represent a powerful alternative to the traditional Feynman-Kac formula, particularly in the high- and low-temperature regimes. To illustrate this point, we apply our local-time representation to analyze the asymptotic behavior of the Bloch density matrix at low temperatures. Further salient issues, such as connections with the Sturm-Liouville theory and the Rayleigh-Ritz variational principle, are also discussed. PMID:26764662
Variational time integrators in computational solid mechanics
NASA Astrophysics Data System (ADS)
Lew, Adrian Jose
This thesis develops the theory and implementation of variational integrators for computational solid mechanics problems, and to some extent, for fluid mechanics problems as well. Variational integrators for finite dimensional mechanical systems are succinctly reviewed, and used as the foundations for the extension to continuum systems. The latter is accomplished by way of a space-tune formulation for Lagrangian continuum mechanics that unifies the derivation of tyre balance of linear momentum, energy and configurational forces, all of there as Euler-Lagrange equations of an extended Hamilton's principle. In this formulation, energy conservation and the path independence of the J- and L-integrals are conserved quantities emanating from Noether's theorem. Variational integrators for continuum mechanics are constructed by mimicking this variational structure, and a discrete Noether's theorem for rather general space-tune discretizations is presented. Additionally, the algorithms are automatically (multi)symplectic, and the (multi)symplectic form is uniquely defined by the theory. For instance, in nonlinear elastodynamics the algorithms exactly preserve linear and angular momenta, whenever the continuous system does. A class of variational algorithms is constructed, termed asynchronous variational integrators (AVI), which permit: the selection of independent time steps in each element of a finite element mesh, and the local time steps need riot bear an integral relation to each other. The conservation properties of both synchronous and asynchronous variational integrators are discussed in detail. In particular, AVI are found to nearly conserve energy both locally and globally, a distinguishing feature of variational integrators. The possibility of adapting the elemental time step to exactly satisfy the local energy balance equation, obtained from the extended variational principle, is analyzed. The AVI are also extended to include dissipative systems. The excellent
Hippocampal “Time Cells”: Time versus Path Integration
Kraus, Benjamin J.; Robinson, Robert J.; White, John A.; Eichenbaum, Howard; Hasselmo, Michael E.
2014-01-01
SUMMARY Recent studies have reported the existence of hippocampal “time cells,” neurons that fire at particular moments during periods when behavior and location are relatively constant. However, an alternative explanation of apparent time coding is that hippocampal neurons “path integrate” to encode the distance an animal has traveled. Here, we examined hippocampal neuronal firing patterns as rats ran in place on a treadmill, thus “clamping” behavior and location, while we varied the treadmill speed to distinguish time elapsed from distance traveled. Hippocampal neurons were strongly influenced by time and distance, and less so by minor variations in location. Furthermore, the activity of different neurons reflected integration over time and distance to varying extents, with most neurons strongly influenced by both factors and some significantly influenced by only time or distance. Thus, hippocampal neuronal networks captured both the organization of time and distance in a situation where these dimensions dominated an ongoing experience. PMID:23707613
Integrated Planning for Telepresence with Time Delays
NASA Technical Reports Server (NTRS)
Johnston, Mark D.; Rabe, Kenneth J.
2006-01-01
Teleoperation of remote robotic systems over time delays in the range of 2-10 seconds poses a unique set of challenges. In the context of a supervisory control system for the JSC Robonaut humanoid robot, we have developed an 'intelligent assistant' that integrates an Artificial Intelligence planner (JSHOP2) with execution monitoring of the state of both the human supervisor and the remote robot. The assistant reasons simultaneously about the world state on both sides of the time delay, which represents a novel application of this technology. The purpose of the assistant is to provide advice to the human supervisor about current and future activities, derived from a sequence of high-level goals to be achieved. To do this, the assistant must simultaneously monitor and react to various data sources, including actions taken by the supervisor who is issuing commands to the robot (e.g. with a data glove), actions taken by the robot, and the environment of the robot, both as currently perceived over the time delay, along with the current sequence of goals. We have developed a 'leader/follower' software architecture to handle the dual time-shifted streams of execution feedback. In this paper we describe the integrated planner and its executive, and how it operates in normal and anomaly situations.
NASA Technical Reports Server (NTRS)
Pines, D.
1999-01-01
This is the Performance Verification Report, METSAT (Meteorological Satellites) Phase Locked Oscillator Assembly, P/N 1348360-1, S/N F09 and F10, for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A).
NASA Technical Reports Server (NTRS)
Valdez, A.
2000-01-01
This is the Engineering Test Report, Radiated Emissions and SARR, SARP, DCS Receivers, Link Frequencies EMI Sensitive Band Test Results, AMSU-A1, S/N 109, for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A).
Integrated Planning for Telepresence with Time Delays
NASA Technical Reports Server (NTRS)
Johnston, Mark D.; Rabe, Kenneth J.
2006-01-01
Integrated planning and execution of teleoperations in space with time delays is shown. The topics include: 1) The Problem; 2) Future Robot Surgery? 3) Approach Overview; 4) Robonaut; 5) Normal Planning and Execution; 6) Planner Context; 7) Implementation; 8) Use of JSHOP2; 9) Monitoring and Testing GUI; 10) Normal sequence: first the supervisor acts; 11) then the robot; 12) Robot might be late; 13) Supervisor can work ahead; 14) Deviations from Plan; 15) Robot State Change Example; 16) Accomplished goals skipped in replan; 17) Planning continuity; 18) Supervisor Deviation From Plan; 19) Intentional Deviation; and 20) Infeasible states.
NASA Technical Reports Server (NTRS)
1999-01-01
This is the Performance Verification Report, METSAT (S/N 109) AMSU-A1 Receiver Assemblies, P/N 1356429-1 S/N F06 and P/N 1356409 S/N F06, for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A).
Lottersberger, Francisca; Panza, Andrea; Lucchini, Giovanna; Piatti, Simonetta; Longhese, Maria Pia
2006-06-01
14-3-3 proteins are highly conserved polypeptides that participate in many biological processes by binding phosphorylated target proteins. The Saccharomyces cerevisiae BMH1 and BMH2 genes, whose concomitant deletion is lethal, encode two functionally redundant 14-3-3 isoforms. To gain insights into the essential function(s) shared by these proteins, we searched for high-dosage suppressors of the growth defects of temperature-sensitive bmh mutants. Both the protein kinase C1 (Pkc1) and its upstream regulators Wsc2 and Mid2 were found to act as high dosage suppressors of bmh mutants' temperature sensitivity, indicating a functional interaction between 14-3-3 and Pkc1. Consistent with a role of 14-3-3 proteins in Pkc1-dependent cellular processes, shift to the restrictive temperature of bmh mutants severely impaired initiation of DNA replication, polarization of the actin cytoskeleton, and budding, as well as cell wall integrity. Because Pkc1 acts in concert with the Swi4-Swi6 (SBF) transcriptional activator to control all these processes, the defective G(1)/S transition of bmh mutants might be linked to impaired SBF activity. Indeed, the levels of the G(1) cyclin CLN2 transcripts, which are positively regulated by SBF, were dramatically reduced in bmh mutants. Remarkably, budding and DNA replication defects of bmh mutants were suppressed by CLN2 expression from an SBF-independent promoter, suggesting that 14-3-3 proteins might contribute to regulating the late G(1) transcriptional program. PMID:16648583
Integrated Planning for Telepresence With Time Delays
NASA Technical Reports Server (NTRS)
Johnston, Mark; Rabe, Kenneth
2009-01-01
A conceptual "intelligent assistant" and an artificial-intelligence computer program that implements the intelligent assistant have been developed to improve control exerted by a human supervisor over a robot that is so distant that communication between the human and the robot involves significant signal-propagation delays. The goal of the effort is not only to help the human supervisor monitor and control the state of the robot, but also to improve the efficiency of the robot by allowing the supervisor to "work ahead". The intelligent assistant is an integrated combination of an artificial-intelligence planner and a monitor of states of both the human supervisor and the remote robot. The novelty of the system lies in the way it uses the planner to reason about the states at both ends of the time delay. The purpose served by the assistant is to provide advice to the human supervisor about current and future activities, derived from a sequence of high-level goals to be achieved.
Time, Dynamics and Chaos: Integrating Poincare's 'Non-Integrable Systems'
DOE R&D Accomplishments Database
Prigogine, I.
1990-10-01
This report discusses the nature of time. The author attempts to resolve the conflict between the concept of time reversibility in classical and quantum mechanics with the macroscopic world's irreversibility of time. (LSP)
Time, dynamics and chaos. Integrating Poincare's "non-integrable systems"
Prigogine, I.
1990-01-01
This report discusses the nature of time. The author attempts to resolve the conflict between the concept of time reversibility in classical and quantum mechanics with the macroscopic world's irreversibility of time. (LSP)
Numerical Integration: One Step at a Time
ERIC Educational Resources Information Center
Yang, Yajun; Gordon, Sheldon P.
2016-01-01
This article looks at the effects that adding a single extra subdivision has on the level of accuracy of some common numerical integration routines. Instead of automatically doubling the number of subdivisions for a numerical integration rule, we investigate what happens with a systematic method of judiciously selecting one extra subdivision for…
Feature Integration across Space, Time, and Orientation
ERIC Educational Resources Information Center
Otto, Thomas U.; Ogmen, Haluk; Herzog, Michael H.
2009-01-01
The perception of a visual target can be strongly influenced by flanking stimuli. In static displays, performance on the target improves when the distance to the flanking elements increases--presumably because feature pooling and integration vanishes with distance. Here, we studied feature integration with dynamic stimuli. We show that features of…
40 CFR 147.3109 - Timing of mechanical integrity test.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Timing of mechanical integrity test... Certain Oklahoma Indian Tribes § 147.3109 Timing of mechanical integrity test. The demonstrations of mechanical integrity required by § 146.14(b)(2) of this chapter prior to approval for the operation of...
40 CFR 147.3109 - Timing of mechanical integrity test.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Timing of mechanical integrity test... Certain Oklahoma Indian Tribes § 147.3109 Timing of mechanical integrity test. The demonstrations of mechanical integrity required by § 146.14(b)(2) of this chapter prior to approval for the operation of...
Integrated method for chaotic time series analysis
Hively, L.M.; Ng, E.G.
1998-09-29
Methods and apparatus for automatically detecting differences between similar but different states in a nonlinear process monitor nonlinear data are disclosed. Steps include: acquiring the data; digitizing the data; obtaining nonlinear measures of the data via chaotic time series analysis; obtaining time serial trends in the nonlinear measures; and determining by comparison whether differences between similar but different states are indicated. 8 figs.
Integrated method for chaotic time series analysis
Hively, Lee M.; Ng, Esmond G.
1998-01-01
Methods and apparatus for automatically detecting differences between similar but different states in a nonlinear process monitor nonlinear data. Steps include: acquiring the data; digitizing the data; obtaining nonlinear measures of the data via chaotic time series analysis; obtaining time serial trends in the nonlinear measures; and determining by comparison whether differences between similar but different states are indicated.
NASA Technical Reports Server (NTRS)
Haigh, R.; Krimchansky, S. (Technical Monitor)
2000-01-01
This is the Performance Verification Report, METSAT (S/N 108) AMSU-A1 Receiver Assemblies P/N 1356429-1 S/N F05 and P/N 1356409-1 S/N F05, for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A). The ATP for the AMSU-A Receiver Subsystem, AE-26002/6A, is prepared to describe in detail the configuration of the test setups and the procedures of the tests to verify that the receiver subsystem meets the specifications as required either in the AMSU-A Instrument Performance and Operation Specifications, S-480-80, or in AMSU-A Receiver Subsystem Specifications, AE-26608, derived by the Aerojet System Engineering. Test results that verify the conformance to the specifications demonstrate the acceptability of that particular receiver subsystem.
Calculation of plantar pressure time integral, an alternative approach.
Melai, Tom; IJzerman, T Herman; Schaper, Nicolaas C; de Lange, Ton L H; Willems, Paul J B; Meijer, Kenneth; Lieverse, Aloysius G; Savelberg, Hans H C M
2011-07-01
In plantar pressure measurement, both peak pressure and pressure time integral are used as variables to assess plantar loading. However, pressure time integral shows a high concordance with peak pressure. Many researchers and clinicians use Novel software (Novel GmbH Inc., Munich, Germany) that calculates this variable as the summation of the products of peak pressure and duration per time sample, which is not a genuine integral of pressure over time. Therefore, an alternative calculation method was introduced. The aim of this study was to explore the relevance of this alternative method, in different populations. Plantar pressure variables were measured in 76 people with diabetic polyneuropathy, 33 diabetic controls without polyneuropathy and 19 healthy subjects. Peak pressure and pressure time integral were obtained using Novel software. The quotient of the genuine force time integral over contact area was obtained as the alternative pressure time integral calculation. This new alternative method correlated less with peak pressure than the pressure time integral as calculated by Novel. The two methods differed significantly and these differences varied between the foot sole areas and between groups. The largest differences were found under the metatarsal heads in the group with diabetic polyneuropathy. From a theoretical perspective, the alternative approach provides a more valid calculation of the pressure time integral. In addition, this study showed that the alternative calculation is of added value, along peak pressure calculation, to interpret adapted plantar pressures patterns in particular in patients at risk for foot ulceration. PMID:21737281
Finite difference schemes for long-time integration
NASA Technical Reports Server (NTRS)
Haras, Zigo; Taasan, Shlomo
1993-01-01
Finite difference schemes for the evaluation of first and second derivatives are presented. These second order compact schemes were designed for long-time integration of evolution equations by solving a quadratic constrained minimization problem. The quadratic cost function measures the global truncation error while taking into account the initial data. The resulting schemes are applicable for integration times fourfold, or more, longer than similar previously studied schemes. A similar approach was used to obtain improved integration schemes.
40 CFR 147.3109 - Timing of mechanical integrity test.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Timing of mechanical integrity test... Certain Oklahoma Indian Tribes § 147.3109 Timing of mechanical integrity test. The demonstrations of... Class I well shall, for an existing well, be conducted no more than 90 days prior to application for...
Ubiquitous time variability of integrated stellar populations.
Conroy, Charlie; van Dokkum, Pieter G; Choi, Jieun
2015-11-26
Long-period variable stars arise in the final stages of the asymptotic giant branch phase of stellar evolution. They have periods of up to about 1,000 days and amplitudes that can exceed a factor of three in the I-band flux. These stars pulsate predominantly in their fundamental mode, which is a function of mass and radius, and so the pulsation periods are sensitive to the age of the underlying stellar population. The overall number of long-period variables in a population is directly related to their lifetimes, which is difficult to predict from first principles because of uncertainties associated with stellar mass-loss and convective mixing. The time variability of these stars has not previously been taken into account when modelling the spectral energy distributions of galaxies. Here we construct time-dependent stellar population models that include the effects of long-period variable stars, and report the ubiquitous detection of this expected 'pixel shimmer' in the massive metal-rich galaxy M87. The pixel light curves display a variety of behaviours. The observed variation of 0.1 to 1 per cent is very well matched to the predictions of our models. The data provide a strong constraint on the properties of variable stars in an old and metal-rich stellar population, and we infer that the lifetime of long-period variables in M87 is shorter by approximately 30 per cent compared to predictions from the latest stellar evolution models. PMID:26570999
The Time Course of Anticipatory Constraint Integration
Kukona, Anuenue; Fang, Shin-Yi; Aicher, Karen A.; Chen, Helen; Magnuson, James S.
2011-01-01
Several studies have demonstrated that as listeners hear sentences describing events in a scene, their eye movements anticipate upcoming linguistic items predicted by the unfolding relationship between scene and sentence. While this may reflect active prediction based on structural or contextual expectations, the influence of local thematic priming between words has not been fully examined. In Experiment 1, we presented verbs (e.g., arrest) in active (Subject-Verb-Object) sentences with displays containing verb-related patients (e.g., crook) and agents (e.g., policeman). We examined patient and agent fixations following the verb, after the agent role had been filled by another entity, but prior to bottom-up specification of the object. Participants were nearly as likely to fixate agents “anticipatorily” as patients, even though the agent role was already filled. However, the slight patient advantage suggested simultaneous influences of both local priming and active prediction. In Experiment 2, using passives (Object-Verb-Subject), we found stronger, but still graded influences of role prediction when more time elapsed between verb and target, and more syntactic cues were available. We interpret anticipatory fixations as emerging from constraint-based processes that involve both non-predictive thematic priming and active prediction. PMID:21237450
Transit light curves with finite integration time: Fisher information analysis
Price, Ellen M.; Rogers, Leslie A.
2014-10-10
Kepler has revolutionized the study of transiting planets with its unprecedented photometric precision on more than 150,000 target stars. Most of the transiting planet candidates detected by Kepler have been observed as long-cadence targets with 30 minute integration times, and the upcoming Transiting Exoplanet Survey Satellite will record full frame images with a similar integration time. Integrations of 30 minutes affect the transit shape, particularly for small planets and in cases of low signal to noise. Using the Fisher information matrix technique, we derive analytic approximations for the variances and covariances on the transit parameters obtained from fitting light curve photometry collected with a finite integration time. We find that binning the light curve can significantly increase the uncertainties and covariances on the inferred parameters when comparing scenarios with constant total signal to noise (constant total integration time in the absence of read noise). Uncertainties on the transit ingress/egress time increase by a factor of 34 for Earth-size planets and 3.4 for Jupiter-size planets around Sun-like stars for integration times of 30 minutes compared to instantaneously sampled light curves. Similarly, uncertainties on the mid-transit time for Earth and Jupiter-size planets increase by factors of 3.9 and 1.4. Uncertainties on the transit depth are largely unaffected by finite integration times. While correlations among the transit depth, ingress duration, and transit duration all increase in magnitude with longer integration times, the mid-transit time remains uncorrelated with the other parameters. We provide code in Python and Mathematica for predicting the variances and covariances at www.its.caltech.edu/∼eprice.
A CMOS integrated timing discriminator circuit for fast scintillation counters
Jochmann, M.W.
1998-06-01
Based on a zero-crossing discriminator using a CR differentiation network for pulse shaping, a new CMOS integrated timing discriminator circuit is proposed for fast (t{sub r} {ge} 2 ns) scintillation counters at the cooler synchrotron COSY-Juelich. By eliminating the input signal`s amplitude information by means of an analog continuous-time divider, a normalized pulse shape at the zero-crossing point is gained over a wide dynamic input amplitude range. In combination with an arming comparator and a monostable multivibrator this yields in a highly precise timing discriminator circuit, that is expected to be useful in different time measurement applications. First measurement results of a CMOS integrated logarithmic amplifier, which is part of the analog continuous-time divider, agree well with the corresponding simulations. Moreover, SPICE simulations of the integrated discriminator circuit promise a time walk well below 200 ps (FWHM) over a 40 dB input amplitude dynamic range.
Exponential Methods for the Time Integration of Schroedinger Equation
Cano, B.; Gonzalez-Pachon, A.
2010-09-30
We consider exponential methods of second order in time in order to integrate the cubic nonlinear Schroedinger equation. We are interested in taking profit of the special structure of this equation. Therefore, we look at symmetry, symplecticity and approximation of invariants of the proposed methods. That will allow to integrate till long times with reasonable accuracy. Computational efficiency is also our aim. Therefore, we make numerical computations in order to compare the methods considered and so as to conclude that explicit Lawson schemes projected on the norm of the solution are an efficient tool to integrate this equation.
ARTEMIS: Ares Real Time Environments for Modeling, Integration, and Simulation
NASA Technical Reports Server (NTRS)
Hughes, Ryan; Walker, David
2009-01-01
This slide presentation reviews the use of ARTEMIS in the development and testing of the ARES launch vehicles. Ares Real Time Environment for Modeling, Simulation and Integration (ARTEMIS) is the real time simulation supporting Ares I hardware-in-the-loop (HWIL) testing. ARTEMIS accurately models all Ares/Orion/Ground subsystems which interact with Ares avionics components from pre-launch through orbit insertion The ARTEMIS System integration Lab, and the STIF architecture is reviewed. The functional components of ARTEMIS are outlined. An overview of the models and a block diagram is presented.
Integration time in space experiments to test the equivalence principle
NASA Astrophysics Data System (ADS)
Nobili, A. M.; Pegna, R.; Shao, M.; Turyshev, S. G.; Catastini, G.; Anselmi, A.; Spero, R.; Doravari, S.; Comandi, G. L.; Lucchesi, D. M.; De Michele, A.
2014-02-01
The integration time required by space experiments to perform high accuracy tests of the universality of free fall and the weak equivalence principle is a crucial issue. It is inversely proportional to the square of the acceleration to be measured, which is extremely small; the duration of the mission is a severe limitation and experiments in space lack repeatability. An exceedingly long integration time can therefore rule out a mission target. We have evaluated the integration time due to thermal noise from gas damping, Johnson noise and eddy currents—which are independent of the signal frequency—and to internal damping, which is known to decrease with increasing frequency. It is found that at low frequencies thermal noise from internal damping dominates. In the "Galileo Galilei" proposed space experiment to test the equivalence principle to 10-17 the rapid rotation of the satellite (1 Hz) up-converts the signal to a frequency region where thermal noise from internal damping is lower than gas damping and only a factor 2 higher than Johnson noise, with a total integration time of 2.4 to 3.5 hours even in a very conservative estimate. With an adequate readout and additional care in reducing systematics the test could be improved by another order of magnitude, close to 10-18, requiring a hundred times longer—still affordable—integration time of 10 to 14.6 days. μSCOPE, a similar room temperature mission under construction by the French space agency to be launched in 2015, aims at a 10-15 test with an estimated integration time of 1.4 days. Space tests using cold atoms and atom interferometry have been proposed to be performed on the space station (Q-WEP, to 10-14) and on a dedicated mission (STE-QUEST, to 10-15 like μSCOPE). In this case integration is required in order to reduce single shot noise. European Space Agency funded studies report an integration time of several months and a few years respectively.
A model of interval timing by neural integration
Simen, Patrick; Balci, Fuat; deSouza, Laura; Cohen, Jonathan D.; Holmes, Philip
2011-01-01
We show that simple assumptions about neural processing lead to a model of interval timing as a temporal integration process, in which a noisy firing-rate representation of time rises linearly on average toward a response threshold over the course of an interval. Our assumptions include: that neural spike trains are approximately independent Poisson processes; that correlations among them can be largely cancelled by balancing excitation and inhibition; that neural populations can act as integrators; and that the objective of timed behavior is maximal accuracy and minimal variance. The model accounts for a variety of physiological and behavioral findings in rodents, monkeys and humans, including ramping firing rates between the onset of reward-predicting cues and the receipt of delayed rewards, and universally scale-invariant response time distributions in interval timing tasks. It furthermore makes specific, well-supported predictions about the skewness of these distributions, a feature of timing data that is usually ignored. The model also incorporates a rapid (potentially one-shot) duration-learning procedure. Human behavioral data support the learning rule’s predictions regarding learning speed in sequences of timed responses. These results suggest that simple, integration-based models should play as prominent a role in interval timing theory as they do in theories of perceptual decision making, and that a common neural mechanism may underlie both types of behavior. PMID:21697374
Analysis of a Real-Time Separation Assurance System with Integrated Time-in-Trail Spacing
NASA Technical Reports Server (NTRS)
Aweiss, Arwa S.; Farrahi, Amir H.; Lauderdale, Todd A.; Thipphavong, Adam S.; Lee, Chu H.
2010-01-01
This paper describes the implementation and analysis of an integrated ground-based separation assurance and time-based metering prototype system into the Center-TRACON Automation System. The integration of this new capability accommodates constraints in four-dimensions: position (x-y), altitude, and meter-fix crossing time. Experiments were conducted to evaluate the performance of the integrated system and its ability to handle traffic levels up to twice that of today. Results suggest that the integrated system reduces the number and magnitude of time-in-trail spacing violations. This benefit was achieved without adversely affecting the resolution success rate of the system. Also, the data suggest that the integrated system is relatively insensitive to an increase in traffic of twice the current levels.
Stability of mixed time integration schemes for transient thermal analysis
NASA Technical Reports Server (NTRS)
Liu, W. K.; Lin, J. I.
1982-01-01
A current research topic in coupled-field problems is the development of effective transient algorithms that permit different time integration methods with different time steps to be used simultaneously in various regions of the problems. The implicit-explicit approach seems to be very successful in structural, fluid, and fluid-structure problems. This paper summarizes this research direction. A family of mixed time integration schemes, with the capabilities mentioned above, is also introduced for transient thermal analysis. A stability analysis and the computer implementation of this technique are also presented. In particular, it is shown that the mixed time implicit-explicit methods provide a natural framework for the further development of efficient, clean, modularized computer codes.
A general time element for orbit integration in Cartesian coordinates
NASA Technical Reports Server (NTRS)
Janin, G.; Bond, V. R.
1981-01-01
Two techniques are discussed for increasing the accuracy of the numerical integration of eccentric orbits in Cartesian coordinates. One involves the use of an independent variable different from time; this increases the efficiency of the numerical integration. The other uses a time element, which reduces the in-track error. A general expression is given of a time element valid for an arbitrary independent variable. It is pointed out that this time element makes it possible to switch the independent variable merely by applying a scaling factor; there is no need to change the differential equations of the motion. Eccentric, true, and elliptic anomalies are used as independent variables in the case of a transfer orbit for a geosynchronous orbit. The elliptic anomaly is shown to perform much better than the other classical anomalies.
Orientation, Evaluation, and Integration of Part-Time Nursing Faculty.
Carlson, Joanne S
2015-01-01
This study helps to quantify and describe orientation, evaluation, and integration practices pertaining to part-time clinical nursing faculty teaching in prelicensure nursing education programs. A researcher designed Web-based survey was used to collect information from a convenience sample of part-time clinical nursing faculty teaching in prelicensure nursing programs. Survey questions focused on the amount and type of orientation, evaluation, and integration practices. Descriptive statistics were used to analyze results. Respondents reported on average four hours of orientation, with close to half reporting no more than two hours. Evaluative feedback was received much more often from students than from full-time faculty. Most respondents reported receiving some degree of mentoring and that it was easy to get help from full-time faculty. Respondents reported being most informed about student evaluation procedures, grading, and the steps to take when students are not meeting course objectives, and less informed about changes to ongoing curriculum and policy. PMID:26151905
Integrable nonlinear parity-time-symmetric optical oscillator
NASA Astrophysics Data System (ADS)
Hassan, Absar U.; Hodaei, Hossein; Miri, Mohammad-Ali; Khajavikhan, Mercedeh; Christodoulides, Demetrios N.
2016-04-01
The nonlinear dynamics of a balanced parity-time-symmetric optical microring arrangement are analytically investigated. By considering gain and loss saturation effects, the pertinent conservation laws are explicitly obtained in the Stokes domain, thus establishing integrability. Our analysis indicates the existence of two regimes of oscillatory dynamics and frequency locking, both of which are analogous to those expected in linear parity-time-symmetric systems. Unlike other saturable parity-time-symmetric systems considered before, the model studied in this work first operates in the symmetric regime and then enters the broken parity-time phase.
AH-1S communication switch integration program
NASA Technical Reports Server (NTRS)
Haworth, Loran; Szoboszlay, Zoltan; Shively, Robert; Bick, Frank J.
1989-01-01
The C-6533/ARC communication system as installed on the test AH-1E Cobra helicopter was modified to allow discrete radio selection of all aircraft radios at the cyclic radio/intercommunication system switch. The current Cobra-fleet use of the C-6533 system is cumbersome, particularly during low-altitude operations. Operationally, the current system C-6533 configuration and design requires the pilot to estimate when he can safely remove his hand from an active flight control to select radios during low-altitude flight. The pilot must then physically remove his hand from the flight control, look inside the cockpit to select and verify the radio selection and then effect the selected radio transmission by activating the radio/ICS switch on the cyclic. This condition is potentially hazardous, especially during low-level flight at night in degraded weather. To improve pilot performance, communications effectiveness, and safety, manprint principles were utilized in the selection of a design modification. The modified C-6533 design was kept as basic as possible for potential Cobra-fleet modification. The communications system was modified and the design was subsequently flight-tested by the U.S. Army Aeroflightdynamics Directorate and NASA at the NASA Ames Research Center, Mountain View, California. The design modification enables the Cobra pilot to maintain hands-on flight controls while selecting radios during nap-of-the-Earth (NOE) flight without looking inside the cockpit which resulted in reduced pilot workload ratings, better pilot handling quality ratings and increased flight safety for the NOE flight environment.
The Weight of Time: Affordances for an Integrated Magnitude System
ERIC Educational Resources Information Center
Lu, Aitao; Mo, Lei; Hodges, Bert H.
2011-01-01
In five experiments we explored the effects of weight on time in different action contexts to test the hypothesis that an integrated magnitude system is tuned to affordances. Larger magnitudes generally seem longer; however, Lu and colleagues (2009) found that if numbers were presented as weights in a range heavy enough to affect lifting, the…
Early Pubertal Timing and Girls' Problem Behavior: Integrating Two Hypotheses
ERIC Educational Resources Information Center
Stattin, Hakan; Kerr, Margaret; Skoog, Therese
2011-01-01
Girls' early pubertal timing has been linked in many studies to behavioral problems such as delinquency and substance use. The theoretical explanations for these links have often involved the girls' peer relationships, but contexts have also been considered important in some explanations. By integrating two theoretical models, the…
Chmura, Bartosz; Rode, Michal F.; Sobolewski, Andrzej L.; Lan Zhenggang
2009-10-07
The photoinduced electron-driven proton-transfer dynamics of the water-dimer system has been investigated by time-dependent quantum wave-packet calculations. The main nuclear degrees of freedom driving the system from the Frank-Condon region to the S{sub 0}-S{sub 1} conical intersection are the distance between the oxygen atoms and the displacement of the hydrogen atom from the oxygen-oxygen bond center. Two important coupling modes have been investigated: Rotation of the H-donating water dangling proton and asymmetric stretching of the H-accepting water dangling protons'O{sub a}H bonds. Potential energy surfaces of the ground and lowest excited electronic states have been constructed on the basis of ab initio calculations. The time-dependent quantum wave-packet propagation has been employed within the (2 + 1)-dimensional systems for the description of the nonadiabatic dynamics of water dimer. The effects of the initial vibrational state of the system on the electronic population transfer and dissociation dynamics are presented. To approximate the photochemical behavior of water dimer in bulk water, we add a boundary condition into the (2 + 1)-dimensional systems to simulate the existence of water bulk. The results provide insight into the mechanisms of excited state deactivation of the water-dimer system in gas phase and in bulk water through the electron-driven proton-transfer process.
Bräunig, Jennifer; Schiwy, Sabrina; Broedel, Oliver; Müller, Yvonne; Frohme, Marcus; Hollert, Henner; Keiter, Steffen H
2015-11-01
Zebrafish embryos are being increasingly used as model organisms for the assessment of single substances and complex environmental samples for regulatory purposes. Thus, it is essential to fully understand the xenobiotic metabolism during the different life-stages of early development. The aim of the present study was to determine arylhydrocarbon receptor (AhR)-mediated activity during selected times of early development using qPCR, enzymatic activity through measurement of 7-ethoxyresorufin-O-deethylase (EROD) activity, and protein expression analysis. In the present study, gene expression of cyp1a, cyp1b1, cyp1c1, cyp1c2, and ahr2 as well as EROD activity were investigated up to 120 h postfertilization (hpf) after exposure to either β-naphthoflavone (BNF) or a polycyclic aromatic hydrocarbons (PAH)-contaminated sediment extract from Vering Kanal in Hamburg (VK). Protein expression was measured at 72 hpf after exposure to 20 μg/L BNF. Altered proteins were identified by matrix assisted laser desorption ionization time-of-flight (MALDI-TOF) peptide mass fingerprinting. Distinct patterns of basal messenger RNA (mRNA) expression were found for each of the cyp1 genes, suggesting specific roles during embryonic development. All transcripts were induced by BNF and VK. ahr2 mRNA expression was significantly upregulated after exposure to VK. All cyp1 genes investigated showed a temporal decline in expression at 72 hpf. The significant decline of Hsp 90β protein at 72 hpf after exposure to BNF may suggest an explanation for the decline of cyp1 genes at this time point as Hsp 90β is of major importance for the functioning of the Ah-receptor. EROD activity measured in embryos was significantly induced after 96 hpf of exposure to BNF or VK. Together, these results demonstrate distinct temporal patterns of cyp1 genes and protein activities in zebrafish embryos as well as show a need to investigate further the xenobiotic biotransformation system during early development of
Improved Integral Equation Solution for the First Passage Time of Leaky Integrate-and-Fire Neurons
Dong, `Yi; Mihalas, Stefan; Niebur, Ernst
2011-01-01
An accurate calculation of the first passage time probability density (FPTPD) is essential for computing the likelihood of solutions of the stochastic leaky integrate-and-fire model. The previously proposed numerical calculation of the FPTPD based on the integral equation method discretizes the probability current of the voltage crossing the threshold. While the method is accurate for high noise levels, we show that it results in large numerical errors for small noise. The problem is solved by analytically computing, in each time bin, the mean probability current. Efficiency is further improved by identifying and ignoring time bins with negligible mean probability current. PMID:21105825
Nagy, Bálint; Woth, Gábor; Mérei, Ákos; Nagy, Lilla; Lantos, János; Menyhei, Gábor; Bogár, Lajos; Mühl, Diána
2016-01-01
Background & objectives: Ischaemic stroke is a life burdening disease for which carotid endarterectomy (CEA) is considered a gold standard intervention. Pro-inflammatory markers like matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) and S-100 Beta (S100B) may have a role in the early inflammation and cognitive decline following CEA. This study was aimed to describe the perioperative time courses and correlations between of MMP-9, TIMP-1 and S100B following CEA. Methods: Fifty four patients scheduled for CEA were enrolled. Blood samples were collected at four time points, T1: preoperative, T2: 60 min after cross-clamp release, T3: first postoperative morning, T4: third postoperative morning. Twenty atherosclerotic patients were included as controls. Plasma MMP-9, TIMP-1 and S100B levels were estimated by ELISA. Results: TIMP-1 was decreased significantly in the CEA group (P<0.01). Plasma MMP-9 was elevated and remained elevated from T1-4 in the CEA group (P<0.05) with a marked elevation in T3 compared to T1 (P<0.05). MMP-9/TIMP-1 was elevated in the CEA group and increased further by T2 and T3 (P<0.05). S100B was elevated on T2 and decreased on T3-4 compared to T1. Interpretation & conclusions: Our study provides information on the dynamic changes of MMP-9-TIMP-1 system and S100B in the perioperative period. Preoperative reduction of TIMP-1 might be predictive for shunt requirement but future studies are required for verification. PMID:27121520
PBO Integrated Real-Time Observing Sites at Volcanic Sites
NASA Astrophysics Data System (ADS)
Mencin, D.; Jackson, M.; Borsa, A.; Feaux, K.; Smith, S.
2009-05-01
The Plate Boundary Observatory, an element of NSF's EarthScope program, has six integrated observatories in Yellowstone and four on Mt St Helens. These observatories consist of some combination of borehole strainmeters, borehole seismometers, GPS, tiltmeters, pore pressure, thermal measurements and meteorological data. Data from all these instruments have highly variable data rates and formats, all synchronized to GPS time which can cause significant congestion of precious communication resources. PBO has been experimenting with integrating these data streams to both maximize efficiency and minimize latency through the use of software that combines the streams, like Antelope, and VPN technologies.
Multistep matrix integrators for real-time simulation
NASA Technical Reports Server (NTRS)
De Abreu-Garcia, J. A.; Hartley, T. T.
1990-01-01
An explicit linear multistep matrix-integration technique is presented for vector systems of ODEs which employs the stability region placement approach to permit the time-step to be chosen independently of system eigenvalues. Closed-form solutions for the general p-step method and the case where the system matrix has zero eigenvalues are given. It is shown that system mode shapes are preserved over the integration process, and that the technique remains applicable to systems with eigenvalues at their origin without need for computing a matrix inversion.
Integrated real-time fracture-diagnostics instrumentation system
Engi, D
1983-01-01
The use of an integrated, real-time fracture-diagnostics instrumentation system for the control of the fracturing treatment during massive hydraulic fracturing is proposed. The proposed system consists of four subsystems: an internal-fracture-pressure measurement system, a fluid-flow measurement system, a borehole seismic system, and a surface-electric-potential measurement system. This use of borehole seismic and surface-electric-potential measurements, which are essentially away-from-the-wellbore measurements, in conjunction with the use of the more commonly used types of measurements, i.e., at-the-wellbore pressure and fluid-flow measurements, is a distinctive feature of the composite real-time diagnostics system. Currently, the real-time capabilities of the individual subsystems are being developed, and the problems associated with their integration into a complete, computer-linked instrumentation system are being addressed. 2 figures.
Multisensory integration: the case of a time window of gesture-speech integration.
Obermeier, Christian; Gunter, Thomas C
2015-02-01
This experiment investigates the integration of gesture and speech from a multisensory perspective. In a disambiguation paradigm, participants were presented with short videos of an actress uttering sentences like "She was impressed by the BALL, because the GAME/DANCE...." The ambiguous noun (BALL) was accompanied by an iconic gesture fragment containing information to disambiguate the noun toward its dominant or subordinate meaning. We used four different temporal alignments between noun and gesture fragment: the identification point (IP) of the noun was either prior to (+120 msec), synchronous with (0 msec), or lagging behind the end of the gesture fragment (-200 and -600 msec). ERPs triggered to the IP of the noun showed significant differences for the integration of dominant and subordinate gesture fragments in the -200, 0, and +120 msec conditions. The outcome of this integration was revealed at the target words. These data suggest a time window for direct semantic gesture-speech integration ranging from at least -200 up to +120 msec. Although the -600 msec condition did not show any signs of direct integration at the homonym, significant disambiguation was found at the target word. An explorative analysis suggested that gesture information was directly integrated at the verb, indicating that there are multiple positions in a sentence where direct gesture-speech integration takes place. Ultimately, this would implicate that in natural communication, where a gesture lasts for some time, several aspects of that gesture will have their specific and possibly distinct impact on different positions in an utterance. PMID:25061929
Orbital flux integrations: Parameter values for effective computer time reductions
NASA Technical Reports Server (NTRS)
Stassinopoulos, E. G.
1974-01-01
To improve computer utilization and to reduce the cost of orbital flux integrations, the effects of integration parameters 'duration' (T) and 'stepsize' (delta t) on integration results were investigated. Over given ranges of T and delta t, and within specified acceptable accuracy restraints, optimal values of these parameters were established for circular subsynchronous trajectories, in terms of the variables altitude (H) and inclination (i). It is shown that (1) above a certain statistically important value, duration is independent of both h and i; (2) stepsize has a relative altitude dependence; and (3) stepsize is not a function of inclination. The substantial savings in computer time are discussed along with the possibility of greater savings by relaxing accuracy restrictions while not exceeding the minimum model-associated uncertainty factors of the environments.
Practical Measures of Integrated Information for Time-Series Data
Barrett, Adam B.; Seth, Anil K.
2011-01-01
A recent measure of ‘integrated information’, ΦDM, quantifies the extent to which a system generates more information than the sum of its parts as it transitions between states, possibly reflecting levels of consciousness generated by neural systems. However, ΦDM is defined only for discrete Markov systems, which are unusual in biology; as a result, ΦDM can rarely be measured in practice. Here, we describe two new measures, ΦE and ΦAR, that overcome these limitations and are easy to apply to time-series data. We use simulations to demonstrate the in-practice applicability of our measures, and to explore their properties. Our results provide new opportunities for examining information integration in real and model systems and carry implications for relations between integrated information, consciousness, and other neurocognitive processes. However, our findings pose challenges for theories that ascribe physical meaning to the measured quantities. PMID:21283779
Dynamic time warp pattern matching using an integrated multiprocessing array
Weste, N.; Burr, D.J.; Ackland, B.D.
1983-08-01
Dynamic time warping is a well-established technique for time alignment and comparison of speech and image patterns. This paper describes the architecture, algorithms and design of a CMOS integrated processing array used for computing the dynamic time warp algorithm. Emphasis is placed on speech recognition applications because of the real-time constraints imposed by isolated and continuous speech recognition. High throughput is obtained through the use of extensive pipelining, parallel computation and simultaneous matching of multiple patterns. A realistic speech recognition application based on 40 nine-component linear predictor coefficient (LPC) vectors per word permits 20000 isolated word comparisons per second or, equivalently, real time recognition of a 20000 word vocabulary. The paper also illustrates a trend in IC design in which the architecture of the system leads to an embodiment which far outperforms solutions based on current design methodologies. 27 references.
Real-time Space-time Integration in GIScience and Geography
Richardson, Douglas B.
2013-01-01
Space-time integration has long been the topic of study and speculation in geography. However, in recent years an entirely new form of space-time integration has become possible in GIS and GIScience: real-time space-time integration and interaction. While real-time spatiotemporal data is now being generated almost ubiquitously, and its applications in research and commerce are widespread and rapidly accelerating, the ability to continuously create and interact with fused space-time data in geography and GIScience is a recent phenomenon, made possible by the invention and development of real-time interactive (RTI) GPS/GIS technology and functionality in the late 1980s and early 1990s. This innovation has since functioned as a core change agent in geography, cartography, GIScience and many related fields, profoundly realigning traditional relationships and structures, expanding research horizons, and transforming the ways geographic data is now collected, mapped, modeled, and used, both in geography and in science and society more broadly. Real-time space-time interactive functionality remains today the underlying process generating the current explosion of fused spatiotemporal data, new geographic research initiatives, and myriad geospatial applications in governments, businesses, and society. This essay addresses briefly the development of these real-time space-time functions and capabilities; their impact on geography, cartography, and GIScience; and some implications for how discovery and change can occur in geography and GIScience, and how we might foster continued innovation in these fields. PMID:24587490
Real-time Space-time Integration in GIScience and Geography.
Richardson, Douglas B
2013-01-01
Space-time integration has long been the topic of study and speculation in geography. However, in recent years an entirely new form of space-time integration has become possible in GIS and GIScience: real-time space-time integration and interaction. While real-time spatiotemporal data is now being generated almost ubiquitously, and its applications in research and commerce are widespread and rapidly accelerating, the ability to continuously create and interact with fused space-time data in geography and GIScience is a recent phenomenon, made possible by the invention and development of real-time interactive (RTI) GPS/GIS technology and functionality in the late 1980s and early 1990s. This innovation has since functioned as a core change agent in geography, cartography, GIScience and many related fields, profoundly realigning traditional relationships and structures, expanding research horizons, and transforming the ways geographic data is now collected, mapped, modeled, and used, both in geography and in science and society more broadly. Real-time space-time interactive functionality remains today the underlying process generating the current explosion of fused spatiotemporal data, new geographic research initiatives, and myriad geospatial applications in governments, businesses, and society. This essay addresses briefly the development of these real-time space-time functions and capabilities; their impact on geography, cartography, and GIScience; and some implications for how discovery and change can occur in geography and GIScience, and how we might foster continued innovation in these fields. PMID:24587490
Mixed time integration methods for transient thermal analysis of structures
NASA Technical Reports Server (NTRS)
Liu, W. K.
1983-01-01
The computational methods used to predict and optimize the thermal-structural behavior of aerospace vehicle structures are reviewed. In general, two classes of algorithms, implicit and explicit, are used in transient thermal analysis of structures. Each of these two methods has its own merits. Due to the different time scales of the mechanical and thermal responses, the selection of a time integration method can be a difficult yet critical factor in the efficient solution of such problems. Therefore mixed time integration methods for transient thermal analysis of structures are being developed. The computer implementation aspects and numerical evaluation of these mixed time implicit-explicit algorithms in thermal analysis of structures are presented. A computationally-useful method of estimating the critical time step for linear quadrilateral element is also given. Numerical tests confirm the stability criterion and accuracy characteristics of the methods. The superiority of these mixed time methods to the fully implicit method or the fully explicit method is also demonstrated.
Timing Analysis with INTEGRAL: Comparing Different Reconstruction Algorithms
NASA Technical Reports Server (NTRS)
Grinberg, V.; Kreykenboehm, I.; Fuerst, F.; Wilms, J.; Pottschmidt, K.; Bel, M. Cadolle; Rodriquez, J.; Marcu, D. M.; Suchy, S.; Markowitz, A.; Nowak, M. A.
2010-01-01
INTEGRAL is one of the few instruments capable of detecting X-rays above 20keV. It is therefore in principle well suited for studying X-ray variability in this regime. Because INTEGRAL uses coded mask instruments for imaging, the reconstruction of light curves of X-ray sources is highly non-trivial. We present results from the comparison of two commonly employed algorithms, which primarily measure flux from mask deconvolution (ii-lc-extract) and from calculating the pixel illuminated fraction (ii-light). Both methods agree well for timescales above about 10 s, the highest time resolution for which image reconstruction is possible. For higher time resolution, ii-light produces meaningful results, although the overall variance of the lightcurves is not preserved.
Time-integrated charge asymmetries at D0
Cheu, E.; /Arizona U.
2006-10-01
We have measured the time-integrated charge asymmetries in dimuon events and semileptonic B{sub s} decays. These results are the most precise semileptonic charge asymmetries in B decays to date. We combine these results with measurements from the decay B{sub s} {yields} J/{psi}{phi} to determine the CP-violating phase {phi}{sub s}. They find {phi}{sub s} = -0.56{sub -0.41}{sup +0.44}.
Time Delay Integration: A Wide-Field Survey Technique
NASA Astrophysics Data System (ADS)
Lapointe, Robert; Hill, E.; Leimer, L.; McMillian, K.; Miller, A.; Prindle, A.
2009-05-01
The Advanced Placement Physics class of Orange Lutheran High School has conducted a survey-imaging pro-ject using a Time Delay Integration (TDI) technique. TDI enables very wide-field images to be collected in the form of long strips of the sky. A series of five consecutive nights were captured, calibrated and compared to re-veal possible transient phenomena such as supernovae, asteroids, and other events that have a noticeable change over 24-hour intervals.
A portable millisecond-integration-time photoelectric photometer.
NASA Technical Reports Server (NTRS)
Mcgraw, J. T.; Wells, D. C.; Wiant, J. R.
1973-01-01
Portable equipment for recording millisecond-integration-time photoelectric photometric data is described. Digital data are reliably recorded on standard 6.35 mm audio grade magnetic tape via a quadradial audio grade tape deck. The system is designed specifically for recording lunar occulations of stars, but the data recording technique is independent of the data source. Recovery of the data is made via minicomputer.
NASA Technical Reports Server (NTRS)
Sukumar, C. V.; Faisal, F. H. M.
1971-01-01
The 1 1s yields 1 1s elastic and 1 1s yields 2 1s and 1 1s yields 2 excitation cross sections of Helium atoms by collision with a charged particle are obtained as analytic functions of incident velocity. The first order time dependent scattering theory is used. Numerical values of electron -He cross sections are obtained for incident energies in the range 30 eV to 800 eV and compared with earlier Born approximation calculations and with available experimental data. It is found that at 100 eV and above, the present results are in good agreement with the experimental results. They are also closer to the experimental results than the corresponding Born calculations.
Integration of Real-Time Data Into Building Automation Systems
Mark J. Stunder; Perry Sebastian; Brenda A. Chube; Michael D. Koontz
2003-04-16
The project goal was to investigate the possibility of using predictive real-time information from the Internet as an input to building management system algorithms. The objectives were to identify the types of information most valuable to commercial and residential building owners, managers, and system designers. To comprehensively investigate and document currently available electronic real-time information suitable for use in building management systems. Verify the reliability of the information and recommend accreditation methods for data and providers. Assess methodologies to automatically retrieve and utilize the information. Characterize equipment required to implement automated integration. Demonstrate the feasibility and benefits of using the information in building management systems. Identify evolutionary control strategies.
Hamiltonian time integrators for Vlasov-Maxwell equations
He, Yang; Xiao, Jianyuan; Zhang, Ruili; Liu, Jian; Qin, Hong; Sun, Yajuan
2015-12-15
Hamiltonian time integrators for the Vlasov-Maxwell equations are developed by a Hamiltonian splitting technique. The Hamiltonian functional is split into five parts, which produces five exactly solvable subsystems. Each subsystem is a Hamiltonian system equipped with the Morrison-Marsden-Weinstein Poisson bracket. Compositions of the exact solutions provide Poisson structure preserving/Hamiltonian methods of arbitrary high order for the Vlasov-Maxwell equations. They are then accurate and conservative over a long time because of the Poisson-preserving nature.
On noise in time-delay integration CMOS image sensors
NASA Astrophysics Data System (ADS)
Levski, Deyan; Choubey, Bhaskar
2016-05-01
Time delay integration sensors are of increasing interest in CMOS processes owing to their low cost, power and ability to integrate with other circuit readout blocks. This paper presents an analysis of the noise contributors in current day CMOS Time-Delay-Integration image sensors with various readout architectures. An analysis of charge versus voltage domain readout modes is presented, followed by a noise classiﬁcation of the existing Analog Accumulator Readout (AAR) and Digital Accumulator Readout (DAR) schemes for TDI imaging. The analysis and classiﬁcation of existing readout schemes include, pipelined charge transfer, buﬀered direct injection, voltage as well as current-mode analog accumulators and all-digital accumulator techniques. Time-Delay-Integration imaging modes in CMOS processes typically use an N-number of readout steps, equivalent to the number of TDI pixel stages. In CMOS TDI sensors, where voltage domain readout is used, the requirements over speed and noise of the ADC readout chain are increased due to accumulation of the dominant voltage readout and ADC noise with every stage N. Until this day, the latter is the primary reason for a leap-back of CMOS TDI sensors as compared to their CCD counterparts. Moreover, most commercial CMOS TDI implementations are still based on a charge-domain readout, mimicking a CCD-like operation mode. Thus, having a good understanding of each noise contributor in the signal chain, as well as its magnitude in diﬀerent readout architectures, is vital for the design of future generation low-noise CMOS TDI image sensors based on a voltage domain readout. This paper gives a quantitative classiﬁcation of all major noise sources for all popular implementations in the literature.
NASA Technical Reports Server (NTRS)
Pines, D.
1999-01-01
This is the Performance Verification Report, METSAT (S/N: 107) AMSU-A1 Receiver Assemblies, P/N 1356429-1, SIN: F04, P/N 1356409- 1, S/N: F04, for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A). The AMSU-A receiver subsystem comprises two separated receiver assemblies; AMSU-A1 and AMSU-A2 (P/N 1356441-1). The AMSU-A1 receiver contains 13 channels and the AMSU-A2 receiver 2 channels. The AMSU-A receiver assembly is further divided into two parts; AMSU-A I - I (P/N 13 5 6429- 1) and AMSU-A 1 -2 (P/N 1356409-1), which contain 9 and 4 channels, respectively. The AMSU-A receiver subsystem is located in between the antenna and signal processing subsystems of the AMSU-A instrument and comprises the RF and IF components from isolators to attenuators. It receives the RF signals from the antenna subsystem, down-converts the RF signals to IF signals, amplifies and defines the IF signals to proper power level and frequency bandwidth as specified for each channel, and inputs the IF signals to the signal processing subsystem. The test reports for the METSAT AMSU-A receiver subsystem are prepared separately for Al and A2 receivers so that each receiver stands alone during integration of instruments into the spacecraft. This test report presents the test data of the N4ETSAT AMSU-A1 Flight Model No. 4 (FM-4) receiver subsystem. The tests are performed per the Acceptance Test Procedure (ATP) for the AMSU-A Receiver Subsystem, AE-26002/6A. The functional performance tests are conducted either at the component or subsystem level. While the component-level tests are performed over the entire operating temperature range predicted by thermal analysis, most subsystem-level tests are conducted at ambient temperature only. Key performances (bandpass characteristics and noise figure) of the receiver subsystem are verified over the operating temperature.
Quantum stopping times stochastic integral in the interacting Fock space
NASA Astrophysics Data System (ADS)
Kang, Yuanbao
2015-08-01
Following the ideas of Hudson [J. Funct. Anal. 34(2), 266-281 (1979)] and Parthasarathy and Sinha [Probab. Theory Relat. Fields 73, 317-349 (1987)], we define a quantum stopping time (QST, for short) τ in the interacting Fock space (IFS, for short), Γ, over L2(ℝ+), which is actually a spectral measure in [0, ∞] such that τ([0, t]) is an adapted process. Motivated by Parthasarathy and Sinha [Probab. Theory Relat. Fields 73, 317-349 (1987)] and Applebaum [J. Funct. Anal. 65, 273-291 (1986)], we also develop a corresponding quantum stopping time stochastic integral (QSTSI, for abbreviations) on the IFS over a subspace of L2(ℝ+) equipped with a filtration. As an application, such integral provides a useful tool for proving that Γ admits a strong factorisation, i.e., Γ = Γτ] ⊗ Γ[τ, where Γτ] and Γ[τ stand for the part "before τ" and the part "after τ," respectively. Additionally, this integral also gives rise to a natural composition operation among QST to make the space of all QSTs a semigroup.
Quantum stopping times stochastic integral in the interacting Fock space
Kang, Yuanbao
2015-08-15
Following the ideas of Hudson [J. Funct. Anal. 34(2), 266-281 (1979)] and Parthasarathy and Sinha [Probab. Theory Relat. Fields 73, 317-349 (1987)], we define a quantum stopping time (QST, for short) τ in the interacting Fock space (IFS, for short), Γ, over L{sup 2}(ℝ{sup +}), which is actually a spectral measure in [0, ∞] such that τ([0, t]) is an adapted process. Motivated by Parthasarathy and Sinha [Probab. Theory Relat. Fields 73, 317-349 (1987)] and Applebaum [J. Funct. Anal. 65, 273-291 (1986)], we also develop a corresponding quantum stopping time stochastic integral (QSTSI, for abbreviations) on the IFS over a subspace of L{sup 2}(ℝ{sup +}) equipped with a filtration. As an application, such integral provides a useful tool for proving that Γ admits a strong factorisation, i.e., Γ = Γ{sub τ]} ⊗ Γ{sub [τ}, where Γ{sub τ]} and Γ{sub [τ} stand for the part “before τ” and the part “after τ,” respectively. Additionally, this integral also gives rise to a natural composition operation among QST to make the space of all QSTs a semigroup.
Development of Visuo-Auditory Integration in Space and Time
Gori, Monica; Sandini, Giulio; Burr, David
2012-01-01
Adults integrate multisensory information optimally (e.g., Ernst and Banks, 2002) while children do not integrate multisensory visual-haptic cues until 8–10 years of age (e.g., Gori et al., 2008). Before that age strong unisensory dominance occurs for size and orientation visual-haptic judgments, possibly reflecting a process of cross-sensory calibration between modalities. It is widely recognized that audition dominates time perception, while vision dominates space perception. Within the framework of the cross-sensory calibration hypothesis, we investigate visual-auditory integration in both space and time with child-friendly spatial and temporal bisection tasks. Unimodal and bimodal (conflictual and not) audio-visual thresholds and PSEs were measured and compared with the Bayesian predictions. In the temporal domain, we found that both in children and adults, audition dominates the bimodal visuo-auditory task both in perceived time and precision thresholds. On the contrary, in the visual-auditory spatial task, children younger than 12 years of age show clear visual dominance (for PSEs), and bimodal thresholds higher than the Bayesian prediction. Only in the adult group did bimodal thresholds become optimal. In agreement with previous studies, our results suggest that also visual-auditory adult-like behavior develops late. We suggest that the visual dominance for space and the auditory dominance for time could reflect a cross-sensory comparison of vision in the spatial visuo-audio task and a cross-sensory comparison of audition in the temporal visuo-audio task. PMID:23060759
Time Triggered Protocol (TTP) for Integration Modular Avionics (IMA)
NASA Technical Reports Server (NTRS)
Gwaltney, David A.; Bauer, Guenther; Jakovljevic, Mirko; Gagea,Leonard; Motzet, Guenter
2006-01-01
This viewgraph presentation is a review of the Time Triggered Protocol, designed to work with NASA's Integrated Safety-Critical Advanced Avionics Communication and Control (ISAACC) system. ISAACC is the product of the Propulsion High-Impact Avionics Technologies (PHIAT) project at NASA Marshall Space Flight Center (MSFC) during FY03 to the end of FY05. The goal is an avionics architecture suitable for control and monitoring of safety critical systems of manned spacecraft. It must be scalable to allow its use in robotic vehicles or launch pad and propulsion test stand monitoring and control systems. The developed IMA should have: a common power supply and rugged chassis for a set of modules, many upgradeable software functions on one module (i.e. processing unit Reduced weight, straightforward update and system integration. It is also important that it have Partitioning and a Memory Management Unit (MMU)
Time delay and integration detectors using charge transfer devices
NASA Technical Reports Server (NTRS)
Mccann, D. H.; White, M. H.; Turly, A. P.
1981-01-01
An imaging system comprises a multi-channel matrix array of CCD devices wherein a number of sensor cells (pixels) in each channel are subdivided and operated in discrete intercoupled groups of subarrays with a readout CCD shift register terminating each end of the channels. Clock voltages, applied to the subarrays, selectively cause charge signal flow in each subarray in either direction independent of the other subarrays. By selective application of four phase clock voltages, either one, two or all three of the sections subarray sections cause charge signal flow in one direction, while the remainder cause charge signal flow in the opposite direction. This creates a form of selective electronic exposure control which provides an effective variable time delay and integration of three, six or nine sensor cells or integration stages. The device is constructed on a semiconductor sustrate with a buried channel and is adapted for front surface imaging through transparent doped tin oxide gates.
FLRW cosmology in Weyl-integrable space-time
Gannouji, Radouane; Nandan, Hemwati; Dadhich, Naresh E-mail: hntheory@yahoo.co.in
2011-11-01
We investigate the Weyl space-time extension of general relativity (GR) for studying the FLRW cosmology through focusing and defocusing of the geodesic congruences. We have derived the equations of evolution for expansion, shear and rotation in the Weyl space-time. In particular, we consider the Starobinsky modification, f(R) = R+βR{sup 2}−2Λ, of gravity in the Einstein-Palatini formalism, which turns out to reduce to the Weyl integrable space-time (WIST) with the Weyl vector being a gradient. The modified Raychaudhuri equation takes the form of the Hill-type equation which is then analysed to study the formation of the caustics. In this model, it is possible to have a Big Bang singularity free cyclic Universe but unfortunately the periodicity turns out to be extremely short.
Integrated Project Scheduling and Staff Assignment with Controllable Processing Times
Framinan, Jose M.
2014-01-01
This paper addresses a decision problem related to simultaneously scheduling the tasks in a project and assigning the staff to these tasks, taking into account that a task can be performed only by employees with certain skills, and that the length of each task depends on the number of employees assigned. This type of problems usually appears in service companies, where both tasks scheduling and staff assignment are closely related. An integer programming model for the problem is proposed, together with some extensions to cope with different situations. Additionally, the advantages of the controllable processing times approach are compared with the fixed processing times. Due to the complexity of the integrated model, a simple GRASP algorithm is implemented in order to obtain good, approximate solutions in short computation times. PMID:24895672
2015-01-01
When simulating molecular systems using deterministic equations of motion (e.g., Newtonian dynamics), such equations are generally numerically integrated according to a well-developed set of algorithms that share commonly agreed-upon desirable properties. However, for stochastic equations of motion (e.g., Langevin dynamics), there is still broad disagreement over which integration algorithms are most appropriate. While multiple desiderata have been proposed throughout the literature, consensus on which criteria are important is absent, and no published integration scheme satisfies all desiderata simultaneously. Additional nontrivial complications stem from simulating systems driven out of equilibrium using existing stochastic integration schemes in conjunction with recently developed nonequilibrium fluctuation theorems. Here, we examine a family of discrete time integration schemes for Langevin dynamics, assessing how each member satisfies a variety of desiderata that have been enumerated in prior efforts to construct suitable Langevin integrators. We show that the incorporation of a novel time step rescaling in the deterministic updates of position and velocity can correct a number of dynamical defects in these integrators. Finally, we identify a particular splitting (related to the velocity Verlet discretization) that has essentially universally appropriate properties for the simulation of Langevin dynamics for molecular systems in equilibrium, nonequilibrium, and path sampling contexts. PMID:24555448
Real-time optimizations for integrated smart network camera
NASA Astrophysics Data System (ADS)
Desurmont, Xavier; Lienard, Bruno; Meessen, Jerome; Delaigle, Jean-Francois
2005-02-01
We present an integrated real-time smart network camera. This system is composed of an image sensor, an embedded PC based electronic card for image processing and some network capabilities. The application detects events of interest in visual scenes, highlights alarms and computes statistics. The system also produces meta-data information that could be shared between other cameras in a network. We describe the requirements of such a system and then show how the design of the system is optimized to process and compress video in real-time. Indeed, typical video-surveillance algorithms as background differencing, tracking and event detection should be highly optimized and simplified to be used in this hardware. To have a good adequation between hardware and software in this light embedded system, the software management is written on top of the java based middle-ware specification established by the OSGi alliance. We can integrate easily software and hardware in complex environments thanks to the Java Real-Time specification for the virtual machine and some network and service oriented java specifications (like RMI and Jini). Finally, we will report some outcomes and typical case studies of such a camera like counter-flow detection.
Integrated Sachs-Wolfe effect in time varying vacuum model
Wang, Y. T.; Gui, Y. X.; Xu, L. X.; Lu, J. B.
2010-04-15
The integrated Sachs-Wolfe (ISW) effect is an important implication for dark energy. In this paper, we have calculated the power spectrum of the ISW effect in the time varying vacuum cosmological model, where the model parameter {beta}=4.407 is obtained by the observational constraint of the growth rate. It is found that the source of the ISW effect is not only affected by the different evolutions of the Hubble function H(a) and the dimensionless matter density {Omega}{sub m}(a), but also by the different growth function D{sub +}(a), all of which are changed due to the presence of a matter production term in the time varying vacuum model. However, the difference of the ISW effect in the {Lambda}(t)CDM model and the {Lambda}CDM model is lessened to a certain extent because of the integration from the time of last scattering to the present. It is implied that the observations of the galaxies with high redshift are required to distinguish the two models.
Integrating timing and conditioning approaches to study behavior.
Kalafut, Kathryn L; Freestone, David M; MacInnis, Mika L M; Church, Russell M
2014-10-01
Skinner and Pavlov had innovative ways to measure both the times of their subject's responses, as well as the rate of their responses. Since then, different subfields within the study of animal behavior have prioritized either the rate or timing of responses, creating a divide in data and theory. Both timing and conditioning fields have proven fruitful, producing large bodies of empirical data and developing sophisticated models. Despite their individual successes, a unified view of simple behavior is still lacking. This may be caused, at least in part, by the differential emphasis on data collection and analysis techniques. The result is that these subfields produce models that fit their data well, but fail to translate to the other domain. This is startling given the fact that both subfields use nearly identical experimental procedures. To highlight similarities within the subfields, and provide empirical data in support of this integration, 18 Sprague-Dawley rats were trained on trace, delay, and backward conditioning procedures. Using these empirical data we discuss how traditional summary measures used by these subfields can be limiting, and suggest methods that may aid in the integration of these subfields toward common goals. PMID:25546101
Time-resolved and time-integrated radiography of fast reactor fuel elements
De Volpi, A.
1981-01-01
The fast-reactor safety program has some unusual requirements in radiography. Applications may be divided into two areas: time-resolved or time-integrated radiography. The fast-neutron hodoscope has supplied all recent time-resolved cineradiographic in-pile fuel-motion data, and various x-ray and photographic techniques have been used for out-of-pile experiments. Thick containers and the large number of radioactive fuel pins involved in safety research have been responsible for some nonconventional applications of time-integrated radiography of stationary objects. Hodoscopes record fuel-motion during transient experiments at the TREAT reactor in the United States and CABRI in France. Other special techniques have been under development for out-of-pile nondestructive radiography of fuel element subassemblies, including fast-neutron and gamma-ray tomographic methods.
Organic Materials for Time-Temperature Integrator Devices.
Cavallini, Massimiliano; Melucci, Manuela
2015-08-12
Time-temperature integrators (TTIs) are devices capable of recording the thermal history of a system. They have an enormous impact in the food and pharmaceutical industries. TTIs exploit several irreversible thermally activated transitions such as recrystallization, dewetting, smoothening, chemical decomposition, and polymorphic transitions, usually considered drawbacks for many technological applications. The aim of this article is to sensitize research groups working in organic synthesis and surface science toward TTI devices, enlarging the prospects of many new materials. We reviewed the principal applications highlighting the need and criticisms of TTIs, which offer a new opportunity for the development of many materials. PMID:26156082
Algorithmic properties of the midpoint predictor-corrector time integrator.
Rider, William J.; Love, Edward; Scovazzi, Guglielmo
2009-03-01
Algorithmic properties of the midpoint predictor-corrector time integration algorithm are examined. In the case of a finite number of iterations, the errors in angular momentum conservation and incremental objectivity are controlled by the number of iterations performed. Exact angular momentum conservation and exact incremental objectivity are achieved in the limit of an infinite number of iterations. A complete stability and dispersion analysis of the linearized algorithm is detailed. The main observation is that stability depends critically on the number of iterations performed.
Linear Time Invariant Models for Integrated Flight and Rotor Control
NASA Astrophysics Data System (ADS)
Olcer, Fahri Ersel
2011-12-01
Recent developments on individual blade control (IBC) and physics based reduced order models of various on-blade control (OBC) actuation concepts are opening up opportunities to explore innovative rotor control strategies for improved rotor aerodynamic performance, reduced vibration and BVI noise, and improved rotor stability, etc. Further, recent developments in computationally efficient algorithms for the extraction of Linear Time Invariant (LTI) models are providing a convenient framework for exploring integrated flight and rotor control, while accounting for the important couplings that exist between body and low frequency rotor response and high frequency rotor response. Formulation of linear time invariant (LTI) models of a nonlinear system about a periodic equilibrium using the harmonic domain representation of LTI model states has been studied in the literature. This thesis presents an alternative method and a computationally efficient scheme for implementation of the developed method for extraction of linear time invariant (LTI) models from a helicopter nonlinear model in forward flight. The fidelity of the extracted LTI models is evaluated using response comparisons between the extracted LTI models and the nonlinear model in both time and frequency domains. Moreover, the fidelity of stability properties is studied through the eigenvalue and eigenvector comparisons between LTI and LTP models by making use of the Floquet Transition Matrix. For time domain evaluations, individual blade control (IBC) and On-Blade Control (OBC) inputs that have been tried in the literature for vibration and noise control studies are used. For frequency domain evaluations, frequency sweep inputs are used to obtain frequency responses of fixed system hub loads to a single blade IBC input. The evaluation results demonstrate the fidelity of the extracted LTI models, and thus, establish the validity of the LTI model extraction process for use in integrated flight and rotor control
Integral ceramic superstructure evaluation using time domain optical coherence tomography
NASA Astrophysics Data System (ADS)
Sinescu, Cosmin; Bradu, Adrian; Topala, Florin I.; Negrutiu, Meda Lavinia; Duma, Virgil-Florin; Podoleanu, Adrian G.
2014-02-01
Optical Coherence Tomography (OCT) is a non-invasive low coherence interferometry technique that includes several technologies (and the corresponding devices and components), such as illumination and detection, interferometry, scanning, adaptive optics, microscopy and endoscopy. From its large area of applications, we consider in this paper a critical aspect in dentistry - to be investigated with a Time Domain (TD) OCT system. The clinical situation of an edentulous mandible is considered; it can be solved by inserting 2 to 6 implants. On these implants a mesostructure will be manufactured and on it a superstructure is needed. This superstructure can be integral ceramic; in this case materials defects could be trapped inside the ceramic layers and those defects could lead to fractures of the entire superstructure. In this paper we demonstrate that a TD-OCT imaging system has the potential to properly evaluate the presence of the defects inside the ceramic layers and those defects can be fixed before inserting the prosthesis inside the oral cavity. Three integral ceramic superstructures were developed by using a CAD/CAM technology. After the milling, the ceramic layers were applied on the core. All the three samples were evaluated by a TD-OCT system working at 1300 nm. For two of the superstructures evaluated, no defects were found in the most stressed areas. The third superstructure presented four ceramic defects in the mentioned areas. Because of those defects the superstructure may fracture. The integral ceramic prosthesis was send back to the dental laboratory to fix the problems related to the material defects found. Thus, TD-OCT proved to be a valuable method for diagnosing the ceramic defects inside the integral ceramic superstructures in order to prevent fractures at this level.
Time Triggered Protocol (TTP) for Integrated Modular Avionics
NASA Technical Reports Server (NTRS)
Motzet, Guenter; Gwaltney, David A.; Bauer, Guenther; Jakovljevic, Mirko; Gagea, Leonard
2006-01-01
Traditional avionics computing systems are federated, with each system provided on a number of dedicated hardware units. Federated applications are physically separated from one another and analysis of the systems is undertaken individually. Integrated Modular Avionics (IMA) takes these federated functions and integrates them on a common computing platform in a tightly deterministic distributed real-time network of computing modules in which the different applications can run. IMA supports different levels of criticality in the same computing resource and provides a platform for implementation of fault tolerance through hardware and application redundancy. Modular implementation has distinct benefits in design, testing and system maintainability. This paper covers the requirements for fault tolerant bus systems used to provide reliable communication between IMA computing modules. An overview of the Time Triggered Protocol (TTP) specification and implementation as a reliable solution for IMA systems is presented. Application examples in aircraft avionics and a development system for future space application are covered. The commercially available TTP controller can be also be implemented in an FPGA and the results from implementation studies are covered. Finally future direction for the application of TTP and related development activities are presented.
Hybrid integrated optic modules for real-time signal processing
NASA Technical Reports Server (NTRS)
Tsai, C. S.
1984-01-01
The most recent progress on four relatively new hybrid integrated optic device modules in LiNbO3 waveguides and one in YIG/GGG waveguide that are currently being studied are discussed. The five hybrid modules include a time-integrating acoustooptic correlator, a channel waveguide acoustooptic frequency shifter/modulator, an electrooptic channel waveguide total internal reflection moculator/switch, an electrooptic analog-to-digital converter using a Fabry-Perot modulator array, and a noncollinear magnetooptic modulator using magnetostatic surface waves. All of these devices possess the desirable characteristics of very large bandwidth (GHz or higher), very small substrate size along the optical path (typically 1.5 cm or less), single-mode optical propagation, and low drive power requirement. The devices utilize either acoustooptic, electrooptic or magnetooptic effects in planar or channel waveguides and, therefore, act as efficient interface devices between a light wave and temporal signals. Major areas of application lie in wideband multichannel optical real-time signal processing and communications. Some of the specific applications include spectral analysis and correlation of radio frequency (RF) signals, fiber-optic sensing, optical computing and multiport switching/routing, and analog-to-digital conversion of wide RF signals.
Wang, S-K; Tsai, W-C; Chou, L-C; Hsieh, Y-C; Chen, K-H; He, T-M; Feng, K-S; Wen, C-R
2011-11-01
Continuous-time core-level photon-stimulated desorption (PSD) spectroscopy was used to investigate the monochromatic soft x-ray photoreactions of CF(2)Cl(2) adsorbed on Si(111)-7 × 7 near the F(1s) edge (681-704 eV). Sequential F(+) PSD spectra were observed as a function of photon exposure at the CF(2)Cl(2)-covered surface (dose = 2.0 × 10(14) molecules cm(-2), ∼0.75 monolayer). The F(+) PSD and total electron yield (TEY) spectra of solid CF(2)Cl(2) near the F(1s) edge were also measured. Both F(+) PSD and TEY spectra depict three features in the energy range of 687-695 eV, and are assigned to the excitations of F(1s) to (13a(1) + 9b(2))[(C-Cl)(∗)], (7b(1) + 14a(1))[(C-F)∗] antibonding and 5p Rydberg orbitals, respectively. Following the Auger decay process, two holes are created in the C-F bonding orbitals producing the 2h1e final state which results in the F(+) desorption. This PSD mechanism, responsible for the F(+) PSD of solid CF(2)Cl(2), is used to explain the first F(+) PSD spectrum in the sequential F(+) PSD spectra. The variation of spectral shapes in the sequential F(+) PSD spectra shows the consumption of adsorbed CF(2)Cl(2) molecules and the production of surface SiF species as a function of photon exposure. The photolysis cross section of the adsorbed CF(2)Cl(2) molecules by photons with varying energy (681-704 eV) is deduced from the sequential F(+) PSD spectra and found to be ∼6.0 × 10(-18) cm(2). PMID:21996577
Wen, C-R; Jang, C-Y; Chou, L-C; Chen, J; Wu, Y-H; Chang, S-C; Tsai, W-C; Liu, C-C; Wang, S-K; Shai, Y
2007-09-21
The continuous-time core-level photon-stimulated desorption (PSD) spectroscopy was employed to monitor the monochromatic soft x-ray-induced reactions of CF3Cl adsorbed on Si(111)-7x7 near the F(1s) edge (681-704 eV). Sequential F+ PSD spectra were measured as a function of photon exposure at the CF3Cl-covered surface (dose=0.3x10(15) molecules/cm2, approximately 0.75 ML). The F+ PSD and total electron yield (TEY) spectra of molecular solid CF3Cl near the F(1s) edge were also measured. Both F+ PSD and TEY spectra show two features at the energy positions of 690.2 and 692.6 eV, and are attributed to the excitations of F(1s) to 11a1[(C-Cl)*] and (8e+12a1)[(C-F)*] antibonding orbitals, respectively. Following Auger decay, two holes are created in the F(2p) lone pair and/or C-F bonding orbitals forming the 2h1e final state which leads to the F+ desorption. This PSD mechanism, which is responsible for the F+ PSD of solid CF3Cl, is employed to interpret the first F+ PSD spectrum in the sequential F+ PSD spectra. The variation of spectrum shapes in the sequential F+ PSD spectra indicates the dissipation of adsorbed CF3Cl molecules and the formation of surface SiF species as a function of photon exposure. From the sequential F+ PSD spectra the photolysis cross section of the adsorbed CF3Cl molecules by photons with varying energy (681-704 eV) is determined to be approximately 1.0x10(-17) cm2. PMID:17887867
NASA Technical Reports Server (NTRS)
Hoffman, David K.; Sharafeddin, Omar; Judson, Richard S.; Kouri, Donald J.
1990-01-01
The time-dependent form of the Lippmann-Schwinger integral equation is used as the basis of several new wave packet propagation schemes. These can be formulated in terms of either the time-dependent wave function or a time-dependent amplitude density. The latter is nonzero only in the region of configuratiaon space for which the potential is nonzero, thereby in principle obviating the necessity of large grids or the use of complex absorbing potentials when resonances cause long collision times (leading, consequently, to long propagation times). Transition amplitudes are obtained in terms of Fourier transforms of the amplitude density from the time to the energy domain. The approach is illustrated by an application to a standard potential scattering model problem where, as in previous studies, the action of the kinetic energy operator is evaluated by fast Fourier transform (FFT) techniques.
A unified discontinuous Galerkin framework for time integration.
Zhao, Shan; Wei, G W
2014-05-15
We introduce a new discontinuous Galerkin approach for time integration. On the basis of the method of weighted residual, numerical quadratures are employed in the finite element time discretization to account for general nonlinear ordinary differential equations. Many different conditions, including explicit, implicit, and symplectic conditions, are enforced for the test functions in the variational analysis to obtain desirable features of the resulting time-stepping scheme. The proposed discontinuous Galerkin approach provides a unified framework to derive various time-stepping schemes, such as low-order one-step methods, Runge-Kutta methods, and multistep methods. On the basis of the proposed framework, several explicit Runge-Kutta methods of different orders are constructed. The derivation of symplectic Runge-Kutta methods has also been realized. The proposed framework allows the optimization of new schemes in terms of several characteristics, such as accuracy, sparseness, and stability. The accuracy optimization is performed on the basis of an analytical form of the error estimation function for a linear test initial value problem. Schemes with higher formal order of accuracy are found to provide more accurate solutions. We have also explored the optimization potential of sparseness, which is related to the general compressive sensing in signal/imaging processing. Two critical dimensions of the stability region, that is, maximal intervals along the imaginary and negative real axes, are employed as the criteria for stability optimization. This gives the largest Courant-Friedrichs-Lewy time steps in solving hyperbolic and parabolic partial differential equations, respectively. Numerical experiments are conducted to validate the optimized time-stepping schemes. PMID:25382889
A unified discontinuous Galerkin framework for time integration
Zhao, Shan; Wei, G. W.
2013-01-01
We introduce a new discontinuous Galerkin approach for time integration. On the basis of the method of weighted residual, numerical quadratures are employed in the finite element time discretization to account for general nonlinear ordinary differential equations. Many different conditions, including explicit, implicit, and symplectic conditions, are enforced for the test functions in the variational analysis to obtain desirable features of the resulting time-stepping scheme. The proposed discontinuous Galerkin approach provides a unified framework to derive various time-stepping schemes, such as low-order one-step methods, Runge–Kutta methods, and multistep methods. On the basis of the proposed framework, several explicit Runge–Kutta methods of different orders are constructed. The derivation of symplectic Runge–Kutta methods has also been realized. The proposed framework allows the optimization of new schemes in terms of several characteristics, such as accuracy, sparseness, and stability. The accuracy optimization is performed on the basis of an analytical form of the error estimation function for a linear test initial value problem. Schemes with higher formal order of accuracy are found to provide more accurate solutions. We have also explored the optimization potential of sparseness, which is related to the general compressive sensing in signal/imaging processing. Two critical dimensions of the stability region, that is, maximal intervals along the imaginary and negative real axes, are employed as the criteria for stability optimization. This gives the largest Courant–Friedrichs–Lewy time steps in solving hyperbolic and parabolic partial differential equations, respectively. Numerical experiments are conducted to validate the optimized time-stepping schemes. PMID:25382889
Xie, Rui; Nguyen, Susan; McKeehan, Kerstin; Wang, Fen; McKeehan, Wallace L; Liu, Leyuan
2011-03-25
The ubiquitously distributed MAP1S is a homologue of the exclusively neuronal distributed microtubule-associated protein 1A and 1B (MAP1A/B). They give rise to multiple isoforms through similar post-translational modification. Isoforms of MAP1S have been implicated in microtubule dynamics and mitotic abnormalities and mitotic cell death. Here we show that ablation of the Map1s gene in mice caused reduction in the B-cell CLL/lymphoma 2 or xL (Bcl-2/xL) and cyclin-dependent kinase inhibitor 1B (P27) protein levels, accumulation of defective mitochondria, and severe defects in response to nutritive stress, suggesting defects in autophagosomal biogenesis and clearance. Furthermore, MAP1S isoforms interacted with the autophagosome-associated light chain 3 of MAP1A/B (LC3), a homologue of yeast autophagy-related gene 8 (ATG8), and recruited it to stable microtubules in a MAP1S and LC3 isoform-dependent mode. In addition, MAP1S interacted with mitochondrion-associated leucine-rich PPR-motif containing protein (LRPPRC) that interacts with the mitophagy initiator and Parkinson disease-related protein Parkin. The three-way interactions of MAP1S isoforms with LC3 and microtubules as well as the interaction of MAP1S with LRPPRC suggest that MAP1S isoforms may play positive roles in integration of autophagic components with microtubules and mitochondria in both autophagosomal biogenesis and degradation. For the first time, our results clarify roles of MAP1S in bridging microtubules and mitochondria with autophagic and mitophagic initiation, maturation, trafficking, and lysosomal clearance. Defects in the MAP1S-regulated autophagy may impact heart disease, cancers, neurodegenerative diseases, and a wide range of other diseases. PMID:21262964
Integrated time-lapse geoelectrical imaging of wetland hydrological processes
NASA Astrophysics Data System (ADS)
Uhlemann, S. S.; Sorensen, J. P. R.; House, A. R.; Wilkinson, P. B.; Roberts, C.; Gooddy, D. C.; Binley, A. M.; Chambers, J. E.
2016-03-01
Wetlands provide crucial habitats, are critical in the global carbon cycle, and act as key biogeochemical and hydrological buffers. The effectiveness of these services is mainly controlled by hydrological processes, which can be highly variable both spatially and temporally due to structural complexity and seasonality. Spatial analysis of 2-D geoelectrical monitoring data integrated into the interpretation of conventional hydrological data has been implemented to provide a detailed understanding of hydrological processes in a riparian wetland. A two-layered hydrological system was observed in the peat. In the lower part of the peat, upwelling of deeper groundwater from underlying deposits was considered the driver for a 30% increase in peat resistivity during Winter/Spring. In Spring/Summer there was a 60% decrease in resistivity in the near-surface peats due to plant transpiration and/or microbial activity. Water exchange between the layers only appeared to be initiated following large drops in the encircling surface water stage. For the first time, we demonstrated that automated interpretation of geoelectrical data can be used to quantify ground movement in the vertical direction. Here, we applied this method to quantify shrink-swell of expandable soils, affecting hydrological parameters, such as, porosity and permeability. This study shows that an integrated interpretation of hydrological and geophysical data can significantly improve the understanding of wetland hydrological processes. Potentially, this approach can provide the basis for the evaluation of ecosystem services and may aid in the optimization of wetland management strategies.
Pneumatic oscillator circuits for timing and control of integrated microfluidics.
Duncan, Philip N; Nguyen, Transon V; Hui, Elliot E
2013-11-01
Frequency references are fundamental to most digital systems, providing the basis for process synchronization, timing of outputs, and waveform synthesis. Recently, there has been growing interest in digital logic systems that are constructed out of microfluidics rather than electronics, as a possible means toward fully integrated laboratory-on-a-chip systems that do not require any external control apparatus. However, the full realization of this goal has not been possible due to the lack of on-chip frequency references, thus requiring timing signals to be provided from off-chip. Although microfluidic oscillators have been demonstrated, there have been no reported efforts to characterize, model, or optimize timing accuracy, which is the fundamental metric of a clock. Here, we report pneumatic ring oscillator circuits built from microfluidic valves and channels. Further, we present a compressible-flow analysis that differs fundamentally from conventional circuit theory, and we show the utility of this physically based model for the optimization of oscillator stability. Finally, we leverage microfluidic clocks to demonstrate circuits for the generation of phase-shifted waveforms, self-driving peristaltic pumps, and frequency division. Thus, pneumatic oscillators can serve as on-chip frequency references for microfluidic digital logic circuits. On-chip clocks and pumps both constitute critical building blocks on the path toward achieving autonomous laboratory-on-a-chip devices. PMID:24145429
Pneumatic oscillator circuits for timing and control of integrated microfluidics
Duncan, Philip N.; Nguyen, Transon V.; Hui, Elliot E.
2013-01-01
Frequency references are fundamental to most digital systems, providing the basis for process synchronization, timing of outputs, and waveform synthesis. Recently, there has been growing interest in digital logic systems that are constructed out of microfluidics rather than electronics, as a possible means toward fully integrated laboratory-on-a-chip systems that do not require any external control apparatus. However, the full realization of this goal has not been possible due to the lack of on-chip frequency references, thus requiring timing signals to be provided from off-chip. Although microfluidic oscillators have been demonstrated, there have been no reported efforts to characterize, model, or optimize timing accuracy, which is the fundamental metric of a clock. Here, we report pneumatic ring oscillator circuits built from microfluidic valves and channels. Further, we present a compressible-flow analysis that differs fundamentally from conventional circuit theory, and we show the utility of this physically based model for the optimization of oscillator stability. Finally, we leverage microfluidic clocks to demonstrate circuits for the generation of phase-shifted waveforms, self-driving peristaltic pumps, and frequency division. Thus, pneumatic oscillators can serve as on-chip frequency references for microfluidic digital logic circuits. On-chip clocks and pumps both constitute critical building blocks on the path toward achieving autonomous laboratory-on-a-chip devices. PMID:24145429
Orthogonally referenced integrated ensemble for navigation and timing
Smith, Stephen Fulton; Moore, James Anthony
2014-04-01
An orthogonally referenced integrated ensemble for navigation and timing includes a dual-polyhedral oscillator array, including an outer sensing array of oscillators and an inner clock array of oscillators situated inside the outer sensing array. The outer sensing array includes a first pair of sensing oscillators situated along a first axis of the outer sensing array, a second pair of sensing oscillators situated along a second axis of the outer sensing array, and a third pair of sensing oscillators situated along a third axis of the outer sensing array. The inner clock array of oscillators includes a first pair of clock oscillators situated along a first axis of the inner clock array, a second pair of clock oscillators situated along a second axis of the inner clock array, and a third pair of clock oscillators situated along a third axis of the inner clock array.
Orthogonally referenced integrated ensemble for navigation and timing
Smith, Stephen Fulton; Moore, James Anthony
2013-02-26
An orthogonally referenced integrated ensemble for navigation and timing includes a dual-polyhedral oscillator array, including an outer sensing array of oscillators and an inner clock array of oscillators situated inside the outer sensing array. The outer sensing array includes a first pair of sensing oscillators situated along a first axis of the outer sensing array, a second pair of sensing oscillators situated along a second axis of the outer sensing array, and a third pair of sensing oscillators situated along a third axis of the outer sensing array. The inner clock array of oscillators includes a first pair of clock oscillators situated along a first axis of the inner clock array, a second pair of clock oscillators situated along a second axis of the inner clock array, and a third pair of clock oscillators situated along a third axis of the inner clock array.
Time Integration Schemes for the Unsteady Navier-stokes Equations
NASA Technical Reports Server (NTRS)
Bijl, Hester; Carpenter, Mark H.; Vatsa, Veer N.
2001-01-01
The efficiency and accuracy of several time integration schemes are investigated for the unsteady Navier-Stokes equations. This study focuses on the efficiency of higher-order Runge-Kutta schemes in comparison with the popular Backward Differencing Formulations. For this comparison an unsteady two-dimensional laminar flow problem is chosen, i.e., flow around a circular cylinder at Re = 1200. It is concluded that for realistic error tolerances (smaller than 10(exp -1)) fourth-and fifth-order Runge-Kutta schemes are the most efficient. For reasons of robustness and computer storage, the fourth-order Runge-Kutta method is recommended. The efficiency of the fourth-order Runge-Kutta scheme exceeds that of second-order Backward Difference Formula by a factor of 2.5 at engineering error tolerance levels (10(exp -1) to 10(exp -2)). Efficiency gains are more dramatic at smaller tolerances.
Imaginary time integration method using a quantum lattice gas approach
NASA Astrophysics Data System (ADS)
Oganesov, Armen; Flint, Christopher; Vahala, George; Vahala, Linda; Yepez, Jeffrey; Soe, Min
2016-02-01
By modifying the collision operator in the quantum lattice gas (QLG) algorithm one can develop an imaginary time (IT) integration to determine the ground state solutions of the Schrödinger equation and its variants. These solutions are compared to those found by other methods (in particular the backward-Euler finite-difference scheme and the quantum lattice Boltzmann). In particular, the ground state of the quantum harmonic oscillator is considered as well as bright solitons in the one-dimensional (1D) non-linear Schrödinger equation. The dark solitons in an external potential are then determined. An advantage of the QLG IT algorithm is the avoidance of any real/complex matrix inversion and that its extension to arbitrary dimensions is straightforward.
Integrating Real-time Earthquakes into Natural Hazard Courses
NASA Astrophysics Data System (ADS)
Furlong, K. P.; Benz, H. M.; Whitlock, J. S.; Bittenbinder, A. N.; Bogaert, B. B.
2001-12-01
Natural hazard courses are playing an increasingly important role in college and university earth science curricula. Students' intrinsic curiosity about the subject and the potential to make the course relevant to the interests of both science and non-science students make natural hazards courses popular additions to a department's offerings. However, one vital aspect of "real-life" natural hazard management that has not translated well into the classroom is the real-time nature of both events and response. The lack of a way to entrain students into the event/response mode has made implementing such real-time activities into classroom activities problematic. Although a variety of web sites provide near real-time postings of natural hazards, students essentially learn of the event after the fact. This is particularly true for earthquakes and other events with few precursors. As a result, the "time factor" and personal responsibility associated with natural hazard response is lost to the students. We have integrated the real-time aspects of earthquake response into two natural hazard courses at Penn State (a 'general education' course for non-science majors, and an upper-level course for science majors) by implementing a modification of the USGS Earthworm system. The Earthworm Database Management System (E-DBMS) catalogs current global seismic activity. It provides earthquake professionals with real-time email/cell phone alerts of global seismic activity and access to the data for review/revision purposes. We have modified this system so that real-time response can be used to address specific scientific, policy, and social questions in our classes. As a prototype of using the E-DBMS in courses, we have established an Earthworm server at Penn State. This server receives national and global seismic network data and, in turn, transmits the tailored alerts to "on-duty" students (e-mail, pager/cell phone notification). These students are responsible to react to the alarm
Compact time- and space-integrating SAR processor: performance analysis
NASA Astrophysics Data System (ADS)
Haney, Michael W.; Levy, James J.; Michael, Robert R., Jr.; Christensen, Marc P.
1995-06-01
Progress made during the previous 12 months toward the fabrication and test of a flight demonstration prototype of the acousto-optic time- and space-integrating real-time SAR image formation processor is reported. Compact, rugged, and low-power analog optical signal processing techniques are used for the most computationally taxing portions of the SAR imaging problem to overcome the size and power consumption limitations of electronic approaches. Flexibility and performance are maintained by the use of digital electronics for the critical low-complexity filter generation and output image processing functions. The results reported for this year include tests of a laboratory version of the RAPID SAR concept on phase history data generated from real SAR high-resolution imagery; a description of the new compact 2D acousto-optic scanner that has a 2D space bandwidth product approaching 106 sports, specified and procured for NEOS Technologies during the last year; and a design and layout of the optical module portion of the flight-worthy prototype.
Testing Gravity Against Early Time Integrated Sachs-Wolfe Effect
Zhang, Pengjie; /Shanghai, Astron. Observ. /Fermilab
2005-11-01
A generic prediction of general relativity is that the cosmological linear density growth factor D is scale independent. But in general, modified gravities do not preserve this signature. A scale dependent D can cause time variation in gravitational potential at high redshifts and provides a new cosmological test of gravity, through early time integrated Sachs-Wolfe (ISW) effect-large scale structure (LSS) cross correlation. We demonstrate the power of this test for a class of f(R) gravity, with the form f(R) = {lambda}{sub 1}H{sub 0}{sup 2} exp(-R/{lambda}{sub 2}H{sub 0}{sup 2}). Such f(R) gravity, even with degenerate expansion history to {Lambda}CDM, can produce detectable ISW effect at z {approx}> 3 and l {approx}> 20. Null-detection of such effect would constrain {lambda}{sub 2} to be {lambda}{sub 2} > 1000 at > 95% confidence level. On the other hand, robust detection of ISW-LSS cross correlation at high z will severely challenge general relativity.
Integrated optical deserialiser time sampling based SiGe photoreceiver.
Hai, Mohammed Shafiqul; Ménard, Michaël; Liboiron-Ladouceur, Odile
2015-12-14
A novel photoreceiver architecture enabling parallel processing in the electronic domain of a high-speed optical signal is demonstrated. This allows the electronics to operate at significantly lower frequency than the optical signal and hence reduce power consumption and the impact of parasitics. The photoreceiver performs optical time sampling with four integrated SiGe photodetectors connected in series by waveguide delay lines. Four variations of the optical time sampling receiver are designed and demonstrated which differ by the data rate (10 Gb/s and 20 Gb/s) and silicon delay waveguide loss (2.5 dB/cm and 0.2 dB/cm). The bit error rate performance of the photodetectors in the receiver was measured individually and reached a performance below 1 × 10⁻¹⁰ at an input optical power between 4.8 and 6.3 dBm through an off-chip 50 Ω load at the output. After O/E conversion, the electrical signal (one segment of 2¹⁵ - 1 PRBS data) from each of the photodetector is processed without errors at a quarter of the bit rate, leading to an overall more power efficient receiver front-end. PMID:26698966
Integrated Planning: Consolidating Annual Facility Planning - More Time for Execution
Nelson, J. G.; R., L. Morton; Ramirez, C.; Morris, P. S.; McSwain, J. T.
2011-02-02
Previously, annual planning for Readiness in Technical Base and Facilities (RTBF) at the Nevada National Security Site (NNSS) was fragmented, disconnected, circular, and occurred constantly throughout the fiscal year (FY) comprising 9 of the 12 months, reducing the focus on implementation and execution. This required constant “looking back” instead of “looking forward.” In FY 2009, annual planning was consolidated into one comprehensive integrated plan (IP) for each facility/project, which comprised annual task planning/outyear budgeting, AMPs, and investment planning (i.e., TYIP). In FY 2010, the Risk Management Plans were added to the IPs. The integrated planning process achieved the following: 1) Eliminated fragmented, circular, planning and moved the plan to be more forward-looking; 2) Achieved a 90% reduction in schedule planning timeframe from 40 weeks (9 months) to 6 weeks; 3) Achieved an 80% reduction in cost from just under $1.0M to just over $200K, for a cost savings of nearly $800K (reduced combined effort from over 200 person-weeks to less than 40); 4) Reduced the number of plans generated from 21 plans (1 per facility per plan) per year to 8 plans per year (1 per facility plus 1 program-level IP); 5) Eliminated redundancy in common content between plans and improved consistency and overall quality; 6) Reduced the preparation time and cost of the FY 2010 SEP by 50% due to information provided in the IP; 7) Met the requirements for annual task planning, annual maintenance planning, ten-year investment planning, and risk management plans.
Wen, C.-R.; Jang, C.-Y.; Chou, L.-C.; Chen, J.; Wu, Y.-H.; Chang, S.-C.; Tsai, W.-C.; Liu, C.-C.; Wang, S.-K.; Shai, Y.
2007-09-21
The continuous-time core-level photon-stimulated desorption (PSD) spectroscopy was employed to monitor the monochromatic soft x-ray-induced reactions of CF{sub 3}Cl adsorbed on Si(111)-7x7 near the F(1s) edge (681-704 eV). Sequential F{sup +} PSD spectra were measured as a function of photon exposure at the CF{sub 3}Cl-covered surface (dose=0.3x10{sup 15} molecules/cm{sup 2}, {approx}0.75 ML). The F{sup +} PSD and total electron yield (TEY) spectra of molecular solid CF{sub 3}Cl near the F(1s) edge were also measured. Both F{sup +} PSD and TEY spectra show two features at the energy positions of 690.2 and 692.6 eV, and are attributed to the excitations of F(1s) to 11a{sub 1}[(C-Cl)*] and (8e+12a{sub 1})[(C-F)*] antibonding orbitals, respectively. Following Auger decay, two holes are created in the F(2p) lone pair and/or C-F bonding orbitals forming the 2h1e final state which leads to the F{sup +} desorption. This PSD mechanism, which is responsible for the F{sup +} PSD of solid CF{sub 3}Cl, is employed to interpret the first F{sup +} PSD spectrum in the sequential F{sup +} PSD spectra. The variation of spectrum shapes in the sequential F{sup +} PSD spectra indicates the dissipation of adsorbed CF{sub 3}Cl molecules and the formation of surface SiF species as a function of photon exposure. From the sequential F{sup +} PSD spectra the photolysis cross section of the adsorbed CF{sub 3}Cl molecules by photons with varying energy (681-704 eV) is determined to be {approx}1.0x10{sup -17} cm{sup 2}.
Matlaga, David P; da S L Sternberg, Leonel
2009-02-01
A major advantage of clonal growth forms is the intergenerational transfer of resources through vascular connections (clonal integration). Connections linking ramets can be persistent or ephemeral. For species with ephemeral connections, whether the extent of clonal integration changes over time is unclear. To address this issue, we tracked water movement using an isotopic label and assessed the demographic performance of parent and offspring ramets over time in a severing experiment. Our study system was the understory herb Calathea marantifolia, which has parent ramets that produce vegetative bulbils (clonal offspring) that pass through distinct pre- and post-rooting stages. Little water was transported between parents and offspring, and the direction of movement was primarily from parent to pre-rooting offspring. Anatomical observations of inter-ramet connections showed that vascular bundles were twice as abundant in parent stems compared to inter-ramet connections. Severing inter-ramet connections reduced the growth of offspring ramets but not parents. Survival of pre-rooting offspring was reduced by 10% due to severing, but post-rooting offspring were not affected. Our results suggest that offspring ramets of C. marantifolia are weaned from their parent as they progress from pre- to post-rooting stages. PMID:21628198
3D Vectorial Time Domain Computational Integrated Photonics
Kallman, J S; Bond, T C; Koning, J M; Stowell, M L
2007-02-16
The design of integrated photonic structures poses considerable challenges. 3D-Time-Domain design tools are fundamental in enabling technologies such as all-optical logic, photonic bandgap sensors, THz imaging, and fast radiation diagnostics. Such technologies are essential to LLNL and WFO sponsors for a broad range of applications: encryption for communications and surveillance sensors (NSA, NAI and IDIV/PAT); high density optical interconnects for high-performance computing (ASCI); high-bandwidth instrumentation for NIF diagnostics; micro-sensor development for weapon miniaturization within the Stockpile Stewardship and DNT programs; and applications within HSO for CBNP detection devices. While there exist a number of photonics simulation tools on the market, they primarily model devices of interest to the communications industry. We saw the need to extend our previous software to match the Laboratory's unique emerging needs. These include modeling novel material effects (such as those of radiation induced carrier concentrations on refractive index) and device configurations (RadTracker bulk optics with radiation induced details, Optical Logic edge emitting lasers with lateral optical inputs). In addition we foresaw significant advantages to expanding our own internal simulation codes: parallel supercomputing could be incorporated from the start, and the simulation source code would be accessible for modification and extension. This work addressed Engineering's Simulation Technology Focus Area, specifically photonics. Problems addressed from the Engineering roadmap of the time included modeling the Auston switch (an important THz source/receiver), modeling Vertical Cavity Surface Emitting Lasers (VCSELs, which had been envisioned as part of fast radiation sensors), and multi-scale modeling of optical systems (for a variety of applications). We proposed to develop novel techniques to numerically solve the 3D multi-scale propagation problem for both the microchip
Cryogenic Integrated Offset Compensation for Time Domain SQUID Multiplexing
NASA Astrophysics Data System (ADS)
Prêle, D.; Voisin, F.; Martino, J.; Bréelle, E.; Bordier, G.; Piat, M.
2012-06-01
Superconducting QUantum Interference Device (SQUID) multiplexing is a common technique in the use of large arrays of Transition Edge Sensors (TES). A Time Domain Multiplexer (TDM) combines input TES signals into one output signal using several SQUIDs. Different TES, SQUID and amplifier characteristics induce unavoidable different offsets on the multiplexed signal. Additionally, given the periodicity of the SQUID characteristic, the Flux Locked Loop (FLL) operating point is only defined modulo Φ 0. This can lead to a large output offset. In multiplexed mode, the difference between offsets associated with different pixels can induce a parasitic signal which is often larger than that of the TES. These offset signals drastically constrain the readout dynamic range and thus the maximum gain allowed. They also limit the signal-to-noise ratio, the FLL stability and the multiplexing frequency. Offsets in SQUID readout are discussed and offset compensation for TDM is presented. The dynamic calibration and compensation on a simplified 4:1 TDM are demonstrated in simulation. Dynamic offset compensation is being implemented on a cryogenic SiGe integrated circuit operated at 4 K for 128:1 TDM.
Minimizing the area required for time constants in integrated circuits
NASA Technical Reports Server (NTRS)
Lyons, J. C.
1972-01-01
When a medium- or large-scale integrated circuit is designed, efforts are usually made to avoid the use of resistor-capacitor time constant generators. The capacitor needed for this circuit usually takes up more surface area on the chip than several resistors and transistors. When the use of this network is unavoidable, the designer usually makes an effort to see that the choice of resistor and capacitor combinations is such that a minimum amount of surface area is consumed. The optimum ratio of resistance to capacitance that will result in this minimum area is equal to the ratio of resistance to capacitance which may be obtained from a unit of surface area for the particular process being used. The minimum area required is a function of the square root of the reciprocal of the products of the resistance and capacitance per unit area. This minimum occurs when the area required by the resistor is equal to the area required by the capacitor.
Optimal Real-time Dispatch for Integrated Energy Systems
Firestone, Ryan Michael
2007-05-31
This report describes the development and application of a dispatch optimization algorithm for integrated energy systems (IES) comprised of on-site cogeneration of heat and electricity, energy storage devices, and demand response opportunities. This work is intended to aid commercial and industrial sites in making use of modern computing power and optimization algorithms to make informed, near-optimal decisions under significant uncertainty and complex objective functions. The optimization algorithm uses a finite set of randomly generated future scenarios to approximate the true, stochastic future; constraints are included that prevent solutions to this approximate problem from deviating from solutions to the actual problem. The algorithm is then expressed as a mixed integer linear program, to which a powerful commercial solver is applied. A case study of United States Postal Service Processing and Distribution Centers (P&DC) in four cities and under three different electricity tariff structures is conducted to (1) determine the added value of optimal control to a cogeneration system over current, heuristic control strategies; (2) determine the value of limited electric load curtailment opportunities, with and without cogeneration; and (3) determine the trade-off between least-cost and least-carbon operations of a cogeneration system. Key results for the P&DC sites studied include (1) in locations where the average electricity and natural gas prices suggest a marginally profitable cogeneration system, optimal control can add up to 67% to the value of the cogeneration system; optimal control adds less value in locations where cogeneration is more clearly profitable; (2) optimal control under real-time pricing is (a) more complicated than under typical time-of-use tariffs and (b) at times necessary to make cogeneration economic at all; (3) limited electric load curtailment opportunities can be more valuable as a compliment to the cogeneration system than alone; and
G-larmS: Integrating Real-Time GPS into Earthquake Early Warning
NASA Astrophysics Data System (ADS)
Grapenthin, R.; Johanson, I. A.; Allen, R. M.
2013-12-01
correctly estimate magnitude and finite fault extent and because real-time GPS suffers from a lower signal-to-noise ratio than post-processed data. Here, we follow two strategies to test G-larmS: (1) add simulated static offsets to (archived) real-time time series, and (2) replay archived data that contain static and dynamic motion due to a real event. We test the prototype system for the Bay Area using synthetic data for a Mw 6.9 Hayward Fault Scenario and on data for the 2010 Mw 7.2 El Mayor-Cucapah earthquake. We compare offset estimate time series and the evolution of event characteristics (magnitude, fault geometry, and slip) to model predictions and post-processed results. We find that the dynamic motion of the El-Mayor Cucapah event impacts the evolution of co-seismic offset estimates initially. However, the results converge quickly (about 1 S-wave wavelength) towards co-seismic offsets (within real-time noise) estimated from post-processed data.
National Ignition Facility sub-system design requirements integrated timing system SSDR 1.5.3
Wiedwald, J.; Van Aersau, P.; Bliss, E.
1996-08-26
This System Design Requirement document establishes the performance, design, development, and test requirements for the Integrated Timing System, WBS 1.5.3 which is part of the NIF Integrated Computer Control System (ICCS). The Integrated Timing System provides all temporally-critical hardware triggers to components and equipment in other NIF systems.
CRAY-1S integer vector utility library
Rogers, J.N.; Tooman, T.P.
1982-06-01
This report describes thirty-five integer or packed vector utility routines, and documents their testing. These routines perform various vector searches, linear algebra functions, memory resets, and vector boolean operations. They are written in CAL, the assembly language on the CRAY-1S computer. By utilizing the vector processing features of that machine, they are optimized in terms of run time. Each routine has been extensively tested.
Incremental constitutive formulation for time dependent materials: creep integral approach
NASA Astrophysics Data System (ADS)
Chazal, Claude; Moutou Pitti, Rostand
2011-08-01
This paper deals with the development of a mathematical approach for the solution of linear, non-ageing viscoelastic materials undergoing mechanical deformation. The formulation is derived from integral approach based on a discrete spectrum representation for the creep tensor. Finite difference integration is used to discretize the integral operators. The resulting constitutive model contains an internal state variable which represents the influence of the whole past history of stress and strain. Thus the difficulty of retaining the strain history in computer solutions is avoided. A complete general formulation of linear viscoelastic stress-strain analysis is developed in terms of increments of stresses and strains. Numerical simulations are included in order to validate the incremental constitutive equations.
EMERGING TECHNOLOGIES FOR REAL-TIME AND INTEGRATED AGRICULTURE DECISIONS
Technology Transfer Automated Retrieval System (TEKTRAN)
The papers in this special issue arise from the premise that precision agriculture information increases in value when data collection, data processing, and management actions are integrated. It seems evident that precision agriculture adoption has been hindered, in part, due to the lack of products...
Technology Integration Enhancing Science: Things Take Time Revisited
ERIC Educational Resources Information Center
Shane, Patricia Mills; Wojnowski, Brenda Shumate
2007-01-01
Project TIES (Technology Integration Enhancing Science), a four-year K-8 Technology Literacy Challenge project, combined technology as a tool for teaching and learning with earth and environmental science education. This project provided teachers in two North Carolina school systems with professional development as well as technology equipment and…
Integration of neutron time-of-flight single-crystal Bragg peaks in reciprocal space
Schultz, Arthur J; Joergensen, Mads; Wang, Xiaoping; Mikkelson, Ruth L; Mikkelson, Dennis J; Lynch, Vickie E; Peterson, Peter F; Green, Mark L; Hoffmann, Christina
2014-01-01
The intensity of single crystal Bragg peaks obtained by mapping neutron time-of-flight event data into reciprocal space and integrating in various ways are compared. These include spherical integration with a fixed radius, ellipsoid fitting and integrating of the peak intensity and one-dimensional peak profile fitting. In comparison to intensities obtained by integrating in real detector histogram space, the data integrated in reciprocal space results in better agreement factors and more accurate atomic parameters. Furthermore, structure refinement using integrated intensities from one-dimensional profile fitting is demonstrated to be more accurate than simple peak-minus-background integration.
Multigrid time-accurate integration of Navier-Stokes equations
NASA Technical Reports Server (NTRS)
Arnone, Andrea; Liou, Meng-Sing; Povinelli, Louis A.
1993-01-01
Efficient acceleration techniques typical of explicit steady-state solvers are extended to time-accurate calculations. Stability restrictions are greatly reduced by means of a fully implicit time discretization. A four-stage Runge-Kutta scheme with local time stepping, residual smoothing, and multigridding is used instead of traditional time-expensive factorizations. Some applications to natural and forced unsteady viscous flows show the capability of the procedure.
Advanced time integration algorithms for dislocation dynamics simulations of work hardening
Sills, Ryan B.; Aghaei, Amin; Cai, Wei
2016-04-25
Efficient time integration is a necessity for dislocation dynamics simulations of work hardening to achieve experimentally relevant strains. In this work, an efficient time integration scheme using a high order explicit method with time step subcycling and a newly-developed collision detection algorithm are evaluated. First, time integrator performance is examined for an annihilating Frank–Read source, showing the effects of dislocation line collision. The integrator with subcycling is found to significantly out-perform other integration schemes. The performance of the time integration and collision detection algorithms is then tested in a work hardening simulation. The new algorithms show a 100-fold speed-up relativemore » to traditional schemes. As a result, subcycling is shown to improve efficiency significantly while maintaining an accurate solution, and the new collision algorithm allows an arbitrarily large time step size without missing collisions.« less
Advanced time integration algorithms for dislocation dynamics simulations of work hardening
NASA Astrophysics Data System (ADS)
Sills, Ryan B.; Aghaei, Amin; Cai, Wei
2016-05-01
Efficient time integration is a necessity for dislocation dynamics simulations of work hardening to achieve experimentally relevant strains. In this work, an efficient time integration scheme using a high order explicit method with time step subcycling and a newly-developed collision detection algorithm are evaluated. First, time integrator performance is examined for an annihilating Frank–Read source, showing the effects of dislocation line collision. The integrator with subcycling is found to significantly out-perform other integration schemes. The performance of the time integration and collision detection algorithms is then tested in a work hardening simulation. The new algorithms show a 100-fold speed-up relative to traditional schemes. Subcycling is shown to improve efficiency significantly while maintaining an accurate solution, and the new collision algorithm allows an arbitrarily large time step size without missing collisions.
NASA Astrophysics Data System (ADS)
von Sydow, Lina
2013-10-01
The discontinuous Galerkin method for time integration of the Black-Scholes partial differential equation for option pricing problems is studied and compared with more standard time-integrators. In space an adaptive finite difference discretization is employed. The results show that the dG method are in most cases at least comparable to standard time-integrators and in some cases superior to them. Together with adaptive spatial grids the suggested pricing method shows great qualities.
Photonic integrated circuit as a picosecond pulse timing discriminator.
Lowery, Arthur James; Zhuang, Leimeng
2016-04-18
We report the first experimental demonstration of a compact on-chip optical pulse timing discriminator that is able to provide an output voltage proportional to the relative timing of two 60-ps input pulses on separate paths. The output voltage is intrinsically low-pass-filtered, so the discriminator forms an interface between high-speed optics and low-speed electronics. Potential applications include timing synchronization of multiple pulse trains as a precursor for optical time-division multiplexing, and compact rangefinders with millimeter dimensions. PMID:27137311
Data rate management and real time operation: recursive adaptive frame integration of limited data
NASA Astrophysics Data System (ADS)
Rafailov, Michael K.
2006-08-01
Recursive Limited Frame Integration was proposed as a way to improve frame integration performance and mitigate issues related to high data rate needed to support conventional frame integration. The technique uses two thresholds -one tuned for optimum probability of detection, the other to manage required false alarm rate, and places integration process between those thresholds. This configuration allows a non-linear integration process that, along with Signal-to-Noise Ratio (SNR) gain, provides system designers more capability where cost, weight, or power considerations limit system data rate, processing, or memory capability. However, Recursive Frame Integration Limited may have performance issues when single-frame SNR is really low. Recursive Adaptive Limited Frame Integration was proposed as a means to improve limited integration performance with really low single-frame SNR. It combines the benefits of nonlinear recursive limited frame integration and adaptive thresholds with a kind of conventional frame integration. Adding the third threshold may help in managing real time operations. In the paper the Recursive Frame Integration is presented in form of multiple parallel recursive integration. Such an approach can help not only in data rate management but in mitigation of low single frame SNR issue for Recursive Integration as well as in real time operations with frame integration.
NASA Technical Reports Server (NTRS)
Chao, W. C.
1982-01-01
With appropriate modifications, a recently proposed explicit-multiple-time-step scheme (EMTSS) is incorporated into the UCLA model. In this scheme, the linearized terms in the governing equations that generate the gravity waves are split into different vertical modes. Each mode is integrated with an optimal time step, and at periodic intervals these modes are recombined. The other terms are integrated with a time step dictated by the CFL condition for low-frequency waves. This large time step requires a special modification of the advective terms in the polar region to maintain stability. Test runs for 72 h show that EMTSS is a stable, efficient and accurate scheme.
Multiple time step integrators in ab initio molecular dynamics
Luehr, Nathan; Martínez, Todd J.; Markland, Thomas E.
2014-02-28
Multiple time-scale algorithms exploit the natural separation of time-scales in chemical systems to greatly accelerate the efficiency of molecular dynamics simulations. Although the utility of these methods in systems where the interactions are described by empirical potentials is now well established, their application to ab initio molecular dynamics calculations has been limited by difficulties associated with splitting the ab initio potential into fast and slowly varying components. Here we present two schemes that enable efficient time-scale separation in ab initio calculations: one based on fragment decomposition and the other on range separation of the Coulomb operator in the electronic Hamiltonian. We demonstrate for both water clusters and a solvated hydroxide ion that multiple time-scale molecular dynamics allows for outer time steps of 2.5 fs, which are as large as those obtained when such schemes are applied to empirical potentials, while still allowing for bonds to be broken and reformed throughout the dynamics. This permits computational speedups of up to 4.4x, compared to standard Born-Oppenheimer ab initio molecular dynamics with a 0.5 fs time step, while maintaining the same energy conservation and accuracy.
NASA Technical Reports Server (NTRS)
Valdez, A.
2000-01-01
This is the Engineering Test Report, Radiated Emissions and SARR, SARP, DCS Receivers, Link Frequencies EMI Sensitive Band Test Results, AMSU-A1 SIN 108, for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A).
Integrated Formal Analysis of Timed-Triggered Ethernet
NASA Technical Reports Server (NTRS)
Dutertre, Bruno; Shankar, Nstarajan; Owre, Sam
2012-01-01
We present new results related to the verification of the Timed-Triggered Ethernet (TTE) clock synchronization protocol. This work extends previous verification of TTE based on model checking. We identify a suboptimal design choice in a compression function used in clock synchronization, and propose an improvement. We compare the original design and the improved definition using the SAL model checker.
Optimal Perceived Timing: Integrating Sensory Information with Dynamically Updated Expectations
Di Luca, Massimiliano; Rhodes, Darren
2016-01-01
The environment has a temporal structure, and knowing when a stimulus will appear translates into increased perceptual performance. Here we investigated how the human brain exploits temporal regularity in stimulus sequences for perception. We find that the timing of stimuli that occasionally deviate from a regularly paced sequence is perceptually distorted. Stimuli presented earlier than expected are perceptually delayed, whereas stimuli presented on time and later than expected are perceptually accelerated. This result suggests that the brain regularizes slightly deviant stimuli with an asymmetry that leads to the perceptual acceleration of expected stimuli. We present a Bayesian model for the combination of dynamically-updated expectations, in the form of a priori probability of encountering future stimuli, with incoming sensory information. The asymmetries in the results are accounted for by the asymmetries in the distributions involved in the computational process. PMID:27385184
Optimal Perceived Timing: Integrating Sensory Information with Dynamically Updated Expectations.
Di Luca, Massimiliano; Rhodes, Darren
2016-01-01
The environment has a temporal structure, and knowing when a stimulus will appear translates into increased perceptual performance. Here we investigated how the human brain exploits temporal regularity in stimulus sequences for perception. We find that the timing of stimuli that occasionally deviate from a regularly paced sequence is perceptually distorted. Stimuli presented earlier than expected are perceptually delayed, whereas stimuli presented on time and later than expected are perceptually accelerated. This result suggests that the brain regularizes slightly deviant stimuli with an asymmetry that leads to the perceptual acceleration of expected stimuli. We present a Bayesian model for the combination of dynamically-updated expectations, in the form of a priori probability of encountering future stimuli, with incoming sensory information. The asymmetries in the results are accounted for by the asymmetries in the distributions involved in the computational process. PMID:27385184
Probability distributed time delays: integrating spatial effects into temporal models
2010-01-01
Background In order to provide insights into the complex biochemical processes inside a cell, modelling approaches must find a balance between achieving an adequate representation of the physical phenomena and keeping the associated computational cost within reasonable limits. This issue is particularly stressed when spatial inhomogeneities have a significant effect on system's behaviour. In such cases, a spatially-resolved stochastic method can better portray the biological reality, but the corresponding computer simulations can in turn be prohibitively expensive. Results We present a method that incorporates spatial information by means of tailored, probability distributed time-delays. These distributions can be directly obtained by single in silico or a suitable set of in vitro experiments and are subsequently fed into a delay stochastic simulation algorithm (DSSA), achieving a good compromise between computational costs and a much more accurate representation of spatial processes such as molecular diffusion and translocation between cell compartments. Additionally, we present a novel alternative approach based on delay differential equations (DDE) that can be used in scenarios of high molecular concentrations and low noise propagation. Conclusions Our proposed methodologies accurately capture and incorporate certain spatial processes into temporal stochastic and deterministic simulations, increasing their accuracy at low computational costs. This is of particular importance given that time spans of cellular processes are generally larger (possibly by several orders of magnitude) than those achievable by current spatially-resolved stochastic simulators. Hence, our methodology allows users to explore cellular scenarios under the effects of diffusion and stochasticity in time spans that were, until now, simply unfeasible. Our methodologies are supported by theoretical considerations on the different modelling regimes, i.e. spatial vs. delay-temporal, as indicated
Integrated active sensor system for real time vibration monitoring
NASA Astrophysics Data System (ADS)
Liang, Qijie; Yan, Xiaoqin; Liao, Xinqin; Cao, Shiyao; Lu, Shengnan; Zheng, Xin; Zhang, Yue
2015-11-01
We report a self-powered, lightweight and cost-effective active sensor system for vibration monitoring with multiplexed operation based on contact electrification between sensor and detected objects. The as-fabricated sensor matrix is capable of monitoring and mapping the vibration state of large amounts of units. The monitoring contents include: on-off state, vibration frequency and vibration amplitude of each unit. The active sensor system delivers a detection range of 0-60 Hz, high accuracy (relative error below 0.42%), long-term stability (10000 cycles). On the time dimension, the sensor can provide the vibration process memory by recording the outputs of the sensor system in an extend period of time. Besides, the developed sensor system can realize detection under contact mode and non-contact mode. Its high performance is not sensitive to the shape or the conductivity of the detected object. With these features, the active sensor system has great potential in automatic control, remote operation, surveillance and security systems.
Life-history syndromes: integrating dispersal through space and time.
Buoro, Mathieu; Carlson, Stephanie M
2014-06-01
Recent research has highlighted interdependencies between dispersal and other life-history traits, i.e. dispersal syndromes, thereby revealing constraints on the evolution of dispersal and opportunities for improved ability to predict dispersal by considering suites of dispersal-related traits. This review adds to the growing list of life-history traits linked to spatial dispersal by emphasising the interdependence between dispersal through space and time, i.e. life-history diversity that distributes individuals into separate reproductive events. We reviewed the literature that has simultaneously investigated spatial and temporal dispersal to examine the prediction that traits of these two dispersal strategies are negatively correlated. Our results suggest that negative covariation is widely anticipated from theory. Empirical studies often reported evidence of weak negative covariation, although more complicated patterns were also evident, including across levels of biological organisation. Existing literature has largely focused on plants with dormancy capability, one or two phases of the dispersal process (emigration and/or transfer) and a single level of biological organisation (theory: individual; empirical: species). We highlight patterns of covariation across levels of organisation and conclude with a discussion of the consequences of dispersal through space and time and future research areas that should improve our understanding of dispersal-related life-history syndromes. PMID:24690406
Integrated active sensor system for real time vibration monitoring
Liang, Qijie; Yan, Xiaoqin; Liao, Xinqin; Cao, Shiyao; Lu, Shengnan; Zheng, Xin; Zhang, Yue
2015-01-01
We report a self-powered, lightweight and cost-effective active sensor system for vibration monitoring with multiplexed operation based on contact electrification between sensor and detected objects. The as-fabricated sensor matrix is capable of monitoring and mapping the vibration state of large amounts of units. The monitoring contents include: on-off state, vibration frequency and vibration amplitude of each unit. The active sensor system delivers a detection range of 0–60 Hz, high accuracy (relative error below 0.42%), long-term stability (10000 cycles). On the time dimension, the sensor can provide the vibration process memory by recording the outputs of the sensor system in an extend period of time. Besides, the developed sensor system can realize detection under contact mode and non-contact mode. Its high performance is not sensitive to the shape or the conductivity of the detected object. With these features, the active sensor system has great potential in automatic control, remote operation, surveillance and security systems. PMID:26538293
Integrated active sensor system for real time vibration monitoring.
Liang, Qijie; Yan, Xiaoqin; Liao, Xinqin; Cao, Shiyao; Lu, Shengnan; Zheng, Xin; Zhang, Yue
2015-01-01
We report a self-powered, lightweight and cost-effective active sensor system for vibration monitoring with multiplexed operation based on contact electrification between sensor and detected objects. The as-fabricated sensor matrix is capable of monitoring and mapping the vibration state of large amounts of units. The monitoring contents include: on-off state, vibration frequency and vibration amplitude of each unit. The active sensor system delivers a detection range of 0-60 Hz, high accuracy (relative error below 0.42%), long-term stability (10000 cycles). On the time dimension, the sensor can provide the vibration process memory by recording the outputs of the sensor system in an extend period of time. Besides, the developed sensor system can realize detection under contact mode and non-contact mode. Its high performance is not sensitive to the shape or the conductivity of the detected object. With these features, the active sensor system has great potential in automatic control, remote operation, surveillance and security systems. PMID:26538293
NASA Technical Reports Server (NTRS)
Pines, D.
1998-01-01
Two Flight Model AMSU-A Phase Locked Oscillators (PIN 1348360-1, S/N F07 and F08) have been tested per AES Test Procedure AE-26758 Rev. B, which include full functional testing, vibration testing, thermal testing, and AM/FM Noise testing. Both assemblies satisfactorily passed all performance requirements of the AE-26633 Product Specification. During the thermal cycling of both units, spurs developed 1 MHz from the carrier when the units were cold, and TARs were written to document the anomaly. The symptoms observed in both cases were consistent with inadequate tuning. The units were successfully re-tuned. In the case of F08, re-tuning required a design change which allowed a greater range of possible values for tuning resisters. Both units completed thermal cycling without further delay. The results of the required tests are presented in the following section as test data. As indicated on the test data sheets, all measured data passed all requirements.
NASA Technical Reports Server (NTRS)
Pines, D.
1998-01-01
Two Flight Model AMSU-A Phase Locked Oscillators (P/N 1348360-1, S/Ns F03 and F04) have been tested per AES Test Procedure AE-26758. The tests included vibration testing, thermal cycle testing, AM/FM Noise testing, and full functional testing. EMI/REO 2 Testing was not performed. (See test data for S/N F01). Both AMSU-A Phase Locked Oscillators satisfactorily passed all performance requirements of the AE-26633 Product specification. During thermal cycling of PLO serial number F03, the oven and data logger momentarily lost power, including a loss of data. The unit did not experience any thermal stress. TAR 003134 describes the corrective action. Prior to testing PLO serial number FO4, power was applied to the unit. (+15v,-15v) the unit did not display the proper phase lock. Upon test equipment check out a connector was found to be defective. TAR 003133 describes the corrective action. After completion of testing of PLO serial number F04 was installed into Receiver Assembly F02. Upon testing F02 Receiver Assembly the unit was found not to phase lock at ambient temperature. Removal of PLO Assembly F04 was required. R2 was the real issue. Solithane was secondary. Troubleshooting revealed excessive solithane on inner PLL Assembly cover inhibiting optimum grounding. Also, R2 was reselected which increased the lock range from -30 C to +60 C. TAR 002737 describes the corrective action.
Integrated Monitoring of Mola mola Behaviour in Space and Time.
Sousa, Lara L; López-Castejón, Francisco; Gilabert, Javier; Relvas, Paulo; Couto, Ana; Queiroz, Nuno; Caldas, Renato; Dias, Paulo Sousa; Dias, Hugo; Faria, Margarida; Ferreira, Filipe; Ferreira, António Sérgio; Fortuna, João; Gomes, Ricardo Joel; Loureiro, Bruno; Martins, Ricardo; Madureira, Luis; Neiva, Jorge; Oliveira, Marina; Pereira, João; Pinto, José; Py, Frederic; Queirós, Hugo; Silva, Daniel; Sujit, P B; Zolich, Artur; Johansen, Tor Arne; de Sousa, João Borges; Rajan, Kanna
2016-01-01
Over the last decade, ocean sunfish movements have been monitored worldwide using various satellite tracking methods. This study reports the near-real time monitoring of fine-scale (< 10 m) behaviour of sunfish. The study was conducted in southern Portugal in May 2014 and involved satellite tags and underwater and surface robotic vehicles to measure both the movements and the contextual environment of the fish. A total of four individuals were tracked using custom-made GPS satellite tags providing geolocation estimates of fine-scale resolution. These accurate positions further informed sunfish areas of restricted search (ARS), which were directly correlated to steep thermal frontal zones. Simultaneously, and for two different occasions, an Autonomous Underwater Vehicle (AUV) video-recorded the path of the tracked fish and detected buoyant particles in the water column. Importantly, the densities of these particles were also directly correlated to steep thermal gradients. Thus, both sunfish foraging behaviour (ARS) and possibly prey densities, were found to be influenced by analogous environmental conditions. In addition, the dynamic structure of the water transited by the tracked individuals was described by a Lagrangian modelling approach. The model informed the distribution of zooplankton in the region, both horizontally and in the water column, and the resultant simulated densities positively correlated with sunfish ARS behaviour estimator (rs = 0.184, p<0.001). The model also revealed that tracked fish opportunistically displace with respect to subsurface current flow. Thus, we show how physical forcing and current structure provide a rationale for a predator's fine-scale behaviour observed over a two weeks in May 2014. PMID:27494028
Integrated Monitoring of Mola mola Behaviour in Space and Time
Sousa, Lara L.; López-Castejón, Francisco; Gilabert, Javier; Relvas, Paulo; Couto, Ana; Queiroz, Nuno; Caldas, Renato; Dias, Paulo Sousa; Dias, Hugo; Faria, Margarida; Ferreira, Filipe; Ferreira, António Sérgio; Fortuna, João; Gomes, Ricardo Joel; Loureiro, Bruno; Martins, Ricardo; Madureira, Luis; Neiva, Jorge; Oliveira, Marina; Pereira, João; Pinto, José; Py, Frederic; Queirós, Hugo; Silva, Daniel; Sujit, P. B.; Zolich, Artur; Johansen, Tor Arne; de Sousa, João Borges; Rajan, Kanna
2016-01-01
Over the last decade, ocean sunfish movements have been monitored worldwide using various satellite tracking methods. This study reports the near-real time monitoring of fine-scale (< 10 m) behaviour of sunfish. The study was conducted in southern Portugal in May 2014 and involved satellite tags and underwater and surface robotic vehicles to measure both the movements and the contextual environment of the fish. A total of four individuals were tracked using custom-made GPS satellite tags providing geolocation estimates of fine-scale resolution. These accurate positions further informed sunfish areas of restricted search (ARS), which were directly correlated to steep thermal frontal zones. Simultaneously, and for two different occasions, an Autonomous Underwater Vehicle (AUV) video-recorded the path of the tracked fish and detected buoyant particles in the water column. Importantly, the densities of these particles were also directly correlated to steep thermal gradients. Thus, both sunfish foraging behaviour (ARS) and possibly prey densities, were found to be influenced by analogous environmental conditions. In addition, the dynamic structure of the water transited by the tracked individuals was described by a Lagrangian modelling approach. The model informed the distribution of zooplankton in the region, both horizontally and in the water column, and the resultant simulated densities positively correlated with sunfish ARS behaviour estimator (rs = 0.184, p<0.001). The model also revealed that tracked fish opportunistically displace with respect to subsurface current flow. Thus, we show how physical forcing and current structure provide a rationale for a predator’s fine-scale behaviour observed over a two weeks in May 2014. PMID:27494028
Generation of accurate integral surfaces in time-dependent vector fields.
Garth, Christoph; Krishnan, Han; Tricoche, Xavier; Bobach, Tom; Joy, Kenneth I
2008-01-01
We present a novel approach for the direct computation of integral surfaces in time-dependent vector fields. As opposed to previous work, which we analyze in detail, our approach is based on a separation of integral surface computation into two stages: surface approximation and generation of a graphical representation. This allows us to overcome several limitations of existing techniques. We first describe an algorithm for surface integration that approximates a series of time lines using iterative refinement and computes a skeleton of the integral surface. In a second step, we generate a well-conditioned triangulation. Our approach allows a highly accurate treatment of very large time-varying vector fields in an efficient, streaming fashion. We examine the properties of the presented methods on several example datasets and perform a numerical study of its correctness and accuracy. Finally, we investigate some visualization aspects of integral surfaces. PMID:18988990
Integrating Databases with Maps: The Delivery of Cultural Data through TimeMap.
ERIC Educational Resources Information Center
Johnson, Ian
TimeMap is a unique integration of database management, metadata and interactive maps, designed to contextualise and deliver cultural data through maps. TimeMap extends conventional maps with the time dimension, creating and animating maps "on-the-fly"; delivers them as a kiosk application or embedded in Web pages; links flexibly to detailed…
NASA Astrophysics Data System (ADS)
Romm, I.; Lev, M.; Cukurel, B.
2016-02-01
Thermal-infrared radiation measurements, conducted using an InSb camera, indicated a failure of the reciprocity law for a wide range of radiation intensities and integration times. When reciprocity between radiation flux and integration time was assumed, the radiation estimates, computed from different combinations of output signals and selected integration time values, suffered from imprecisions of up to 12%. Temperature errors of ~4% were predicted for low emissivity surfaces, at all temperatures. A novel empirical methodology, which compensates for multiple nonlinearity effects, is presented. Among different types of models, it is demonstrated that an equation, which represents a power-law dependence of the output signal on integration time best describes the physical system. Experimental procedures are suggested to avoid nonlinearity-related errors.
Design of a semi-custom integrated circuit for the SLAC SLC timing control system
Linstadt, E.
1984-10-01
A semi-custom (gate array) integrated circuit has been designed for use in the SLAC Linear Collider timing and control system. The design process and SLAC's experiences during the phases of the design cycle are described. Issues concerning the partitioning of the design into semi-custom and standard components are discussed. Functional descriptions of the semi-custom integrated circuit and the timing module in which it is used are given.
A new integrator for monitoring time and temperature of steam sterilizers.
Beck, W C
1976-01-01
Steam sterilization is the simplest and most useful method of sterilization of thermostable materials. Sterilization depends upon three factors: time, temperature, and the presence of live steam. For the first time an instrument can be employed to monitor these three factors with immediate readout. This paper contrasts the advantages of this integrator with sterilizer controls, and biological and chemical indicators; and describes methods utilized in testing the integrator. PMID:1012107
An integral equation representation approach for valuing Russian options with a finite time horizon
NASA Astrophysics Data System (ADS)
Jeon, Junkee; Han, Heejae; Kim, Hyeonuk; Kang, Myungjoo
2016-07-01
In this paper, we first describe a general solution for the inhomogeneous Black-Scholes partial differential equation with mixed boundary conditions using Mellin transform techniques. Since Russian options with a finite time horizon are usually formulated into the inhomogeneous free-boundary Black-Scholes partial differential equation with a mixed boundary condition, we apply our method to Russian options and derive an integral equation satisfied by Russian options with a finite time horizon. Furthermore, we present some numerical solutions and plots of the integral equation using recursive integration methods and demonstrate the computational accuracy and efficiency of our method compared to other competing approaches.
Exponential Methods for the Time Integration of Schrödinger Equation
NASA Astrophysics Data System (ADS)
Cano, B.; González-Pachón, A.
2010-09-01
We consider exponential methods of second order in time in order to integrate the cubic nonlinear Schrödinger equation. We are interested in taking profit of the special structure of this equation. Therefore, we look at symmetry, symplecticity and approximation of invariants of the proposed methods. That will allow to integrate till long times with reasonable accuracy. Computational efficiency is also our aim. Therefore, we make numerical computations in order to compare the methods considered and so as to conclude that explicit Lawson schemes projected on the norm of the solution are an efficient tool to integrate this equation.
Li, Lian; Sun, Wei; Zhang, Zhirong; Huang, Yuan
2016-06-28
While highly effective for slowing cancer progression in principle, the c-Myc inhibitor peptide H1-S6A,F8A (H1) has not performed well in tumor studies, in part because it does not pass efficiently through the nuclear envelope. Here we describe a dual-strike strategy in which tumor cells were treated first with N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer-docetaxel (DTX) conjugates (P-DTX), which arrested cells in the G2/M phase and prolonged the period when the nuclear membrane was disassembled. In the second strike, the cells were then treated with P-H1 conjugates, which entered the nucleus and efficiently inhibited c-Myc. The in vitro studies demonstrated that the combination of P-DTX and P-H1 conjugates was sequence-dependent, and P-DTX followed by P-H1 had synergism, which was significantly more effective than reverse sequential delivery, simultaneous co-delivery or monotherapy with P-DTX or P-H1 alone. The in vivo studies showed that sequential delivery of P-DTX followed by P-H1 remarkably slowed the tumor growth and improved the animal survival. This sequential, dual-strike approach provides new opportunities for nuclear-targeted anticancer drug delivery. PMID:27098443
Time series analysis of the developed financial markets' integration using visibility graphs
NASA Astrophysics Data System (ADS)
Zhuang, Enyu; Small, Michael; Feng, Gang
2014-09-01
A time series representing the developed financial markets' segmentation from 1973 to 2012 is studied. The time series reveals an obvious market integration trend. To further uncover the features of this time series, we divide it into seven windows and generate seven visibility graphs. The measuring capabilities of the visibility graphs provide means to quantitatively analyze the original time series. It is found that the important historical incidents that influenced market integration coincide with variations in the measured graphical node degree. Through the measure of neighborhood span, the frequencies of the historical incidents are disclosed. Moreover, it is also found that large "cycles" and significant noise in the time series are linked to large and small communities in the generated visibility graphs. For large cycles, how historical incidents significantly affected market integration is distinguished by density and compactness of the corresponding communities.
NASA Technical Reports Server (NTRS)
Kapper, R.
1998-01-01
The AMSU-A receiver subsystem comprises two separated receiver assemblies; AMSU-Al and AMSU-A2(PN1356441-1). The AMSU-A1 receiver contains 13 channels and the AMSU-A2 receiver 2 channels. The AMSU-AL receiver assembly is further divided into two parts; AMSU-A 1-1 (P/N 1356429-1) and AMSU-A 1-2 (P/N 1356409-1), which contain 9 and 4 channels, respectively. The AMSU-A receiver subsystem stands in between the antenna and signal processing subsystems of the AMSU-A instrument and comprises the RF and IF components from RF isolators to IF attenuators. It receives the RF signals from the antenna subsystem, down-converts the RF signals to IF signals, amplifies and defines the IF signals to proper power level and frequency bandwidth as specified for each channel, and inputs the IF signals to the signal processing subsystem. The test reports for the METSAT AMSU-A receiver subsystem are prepared separately for the A1 and A2 receivers so that each receiver stands alone during integration of instruments into the spacecraft. This test report presents the test data of the METSAT AMSU-A2 Flight Model No.4 (FM4) receiver. The tests are performed per the Acceptance Test Procedure for the AMSU-A Receiver Subsystem, AE-26002/6A. The functional performance tests are conducted either at the component or subsystem level. While the component-level tests are performed over the entire operating temperature range predicted by thermal analysis, the subsystem-level tests are conducted at ambient temperature only.
NASA Technical Reports Server (NTRS)
Bartels, Robert E.
2003-01-01
A variable order method of integrating the structural dynamics equations that is based on the state transition matrix has been developed. The method has been evaluated for linear time variant and nonlinear systems of equations. When the time variation of the system can be modeled exactly by a polynomial it produces nearly exact solutions for a wide range of time step sizes. Solutions of a model nonlinear dynamic response exhibiting chaotic behavior have been computed. Accuracy of the method has been demonstrated by comparison with solutions obtained by established methods.
Creating a Campus Culture of Integrity: Comparing the Perspectives of Full- and Part-Time Faculty
ERIC Educational Resources Information Center
Hudd, Suzanne S.; Apgar, Caroline; Bronson, Eric Franklyn; Lee, Renee Gravois
2009-01-01
Part-time faculty play an important role in creating a culture of integrity on campus, yet they face a number of structural constraints. This paper seeks to improve our understanding of the potentially unique experiences of part-time faculty with academic misconduct and suggests ways to more effectively involve them in campus-wide academic…
NASA Astrophysics Data System (ADS)
Fortunati, Alessandro; Wiggins, Stephen
2014-05-01
The aim of this paper is to extend the result of Giorgilli and Zehnder for aperiodic time dependent systems to a case of nearly integrable convex analytic Hamiltonians. The existence of a normal form and then a stability result are shown in the case of a slow aperiodic time dependence that, under some smallness conditions, is independent of the size of the perturbation.
ERIC Educational Resources Information Center
Taatgen, Niels A.; van Rijn, Hedderik; Anderson, John
2007-01-01
A theory of prospective time perception is introduced and incorporated as a module in an integrated theory of cognition, thereby extending existing theories and allowing predictions about attention and learning. First, a time perception module is established by fitting existing datasets (interval estimation and bisection and impact of secondary…
Building a better leapfrog. [an algorithm for ensuring time symmetry in any integration scheme
NASA Technical Reports Server (NTRS)
Hut, Piet; Makino, Jun; Mcmillan, Steve
1995-01-01
In stellar dynamical computer simulations, as well as other types of simulations using particles, time step size is often held constant in order to guarantee a high degree of energy conservation. In many applications, allowing the time step size to change in time can offer a great saving in computational cost, but variable-size time steps usually imply a substantial degradation in energy conservation. We present a meta-algorithm' for choosing time steps in such a way as to guarantee time symmetry in any integration scheme, thus allowing vastly improved energy conservation for orbital calculations with variable time steps. We apply the algorithm to the familiar leapfrog scheme, and generalize to higher order integration schemes, showing how the stability properties of the fixed-step leapfrog scheme can be extended to higher order, variable-step integrators such as the Hermite method. We illustrate the remarkable properties of these time-symmetric integrators for the case of a highly eccentric elliptical Kepler orbit and discuss applications to more complex problems.
How to Make Additional Time Matter: Integrating Individualized Tutorials into an Extended Day
ERIC Educational Resources Information Center
Kraft, Matthew A.
2015-01-01
Evidence on the effect of extending the school day is decidedly mixed because of the stark differences in how schools use additional time. In this paper, I focus narrowly on the effect of additional time used for individualized tutorials. In 2005, MATCH Charter Public High School integrated two hours of tutorials throughout an extended day. The…
An Approach to Integrate a Space-Time GIS Data Model with High Performance Computers
Wang, Dali; Zhao, Ziliang; Shaw, Shih-Lung
2011-01-01
In this paper, we describe an approach to integrate a Space-Time GIS data model on a high performance computing platform. The Space-Time GIS data model has been developed on a desktop computing environment. We use the Space-Time GIS data model to generate GIS module, which organizes a series of remote sensing data. We are in the process of porting the GIS module into an HPC environment, in which the GIS modules handle large dataset directly via parallel file system. Although it is an ongoing project, authors hope this effort can inspire further discussions on the integration of GIS on high performance computing platforms.
Time perception impairs sensory-motor integration in Parkinson’s disease
2013-01-01
It is well known that perception and estimation of time are fundamental for the relationship between humans and their environment. However, this temporal information processing is inefficient in patients with Parkinson’ disease (PD), resulting in temporal judgment deficits. In general, the pathophysiology of PD has been described as a dysfunction in the basal ganglia, which is a multisensory integration station. Thus, a deficit in the sensorimotor integration process could explain many of the Parkinson symptoms, such as changes in time perception. This physiological distortion may be better understood if we analyze the neurobiological model of interval timing, expressed within the conceptual framework of a traditional information-processing model called “Scalar Expectancy Theory”. Therefore, in this review we discuss the pathophysiology and sensorimotor integration process in PD, the theories and neural basic mechanisms involved in temporal processing, and the main clinical findings about the impact of time perception in PD. PMID:24131660
Tracking the time course of phonetic cue integration during spoken word recognition.
McMurray, Bob; Clayards, Meghan A; Tanenhaus, Michael K; Aslin, Richard N
2008-12-01
Speech perception requires listeners to integrate multiple cues that each contribute to judgments about a phonetic category. Classic studies of trading relations assessed the weights attached to each cue but did not explore the time course of cue integration. Here, we provide the first direct evidence that asynchronous cues to voicing (/b/ vs. /p/) and manner (/b/ vs. /w/) contrasts become available to the listener at different times during spoken word recognition. Using the visual world paradigm, we show that the probability of eye movements to pictures of target and of competitor objects diverge at different points in time after the onset of the target word. These points of divergence correspond to the availability of early (voice onset time or formant transition slope) and late (vowel length) cues to voicing and manner contrasts. These results support a model of cue integration in which phonetic cues are used for lexical access as soon as they are available. PMID:19001568
Exploring the History of Time in an Integrated System: the Ramifications for Water
NASA Astrophysics Data System (ADS)
Green, M. B.; Adams, L. E.; Allen, T. L.; Arrigo, J. S.; Bain, D. J.; Bray, E. N.; Duncan, J. M.; Hermans, C. M.; Pastore, C.; Schlosser, C. A.; Vorosmarty, C. J.; Witherell, B. B.; Wollheim, W. M.; Wreschnig, A. J.
2009-12-01
Characteristic time scales are useful and simple descriptors of geophysical and socio-economic system dynamics. Focusing on the integrative nature of the hydrologic cycle, new insights into system couplings can be gained by compiling characteristic time scales of important processes driving these systems. There are many examples of changing characteristic time scales. Human life expectancy has increased over the recent history of medical advancement. The transport time of goods has decreased with the progression from horse to rail to car to plane. The transport time of information changed with the progression from letter to telegraph to telephone to networked computing. Soil residence time (pedogenesis to estuary deposition) has been influenced by changing agricultural technology, urbanization, and forest practices. Surface water residence times have varied as beaver dams have disappeared and been replaced with modern reservoirs, flood control works, and channelization. These dynamics raise the question of how these types of time scales interact with each other to form integrated Earth system dynamics? Here we explore the coupling of geophysical and socio-economic systems in the northeast United States over the 1600 to 2010 period by examining characteristic time scales. This visualization of many time scales serves as an exploratory analysis, producing new hypotheses about how the integrated system dynamics have evolved over the last 400 years. Specifically, exponential population growth and the evolving strategies to maintain that population appears as fundamental to many of the time scales.
A point implicit time integration technique for slow transient flow problems
Kadioglu, Samet Y.; Berry, Ray A.; Martineau, Richard C.
2015-05-01
We introduce a point implicit time integration technique for slow transient flow problems. The method treats the solution variables of interest (that can be located at cell centers, cell edges, or cell nodes) implicitly and the rest of the information related to same or other variables are handled explicitly. The method does not require implicit iteration; instead it time advances the solutions in a similar spirit to explicit methods, except it involves a few additional function(s) evaluation steps. Moreover, the method is unconditionally stable, as a fully implicit method would be. This new approach exhibits the simplicity of implementation of explicit methods and the stability of implicit methods. It is specifically designed for slow transient flow problems of long duration wherein one would like to perform time integrations with very large time steps. Because the method can be time inaccurate for fast transient problems, particularly with larger time steps, an appropriate solution strategy for a problem that evolves from a fast to a slow transient would be to integrate the fast transient with an explicit or semi-implicit technique and then switch to this point implicit method as soon as the time variation slows sufficiently. We have solved several test problems that result from scalar or systems of flow equations. Our findings indicate the new method can integrate slow transient problems very efficiently; and its implementation is very robust.
NASA Astrophysics Data System (ADS)
Gao, Yingjie; Zhang, Jinhai; Yao, Zhenxing
2016-06-01
The symplectic integration method is popular in high-accuracy numerical simulations when discretizing temporal derivatives; however, it still suffers from time-dispersion error when the temporal interval is coarse, especially for long-term simulations and large-scale models. We employ the inverse time dispersion transform (ITDT) to the third-order symplectic integration method to reduce the time-dispersion error. First, we adopt the pseudospectral algorithm for the spatial discretization and the third-order symplectic integration method for the temporal discretization. Then, we apply the ITDT to eliminate time-dispersion error from the synthetic data. As a post-processing method, the ITDT can be easily cascaded in traditional numerical simulations. We implement the ITDT in one typical exiting third-order symplectic scheme and compare its performances with the performances of the conventional second-order scheme and the rapid expansion method. Theoretical analyses and numerical experiments show that the ITDT can significantly reduce the time-dispersion error, especially for long travel times. The implementation of the ITDT requires some additional computations on correcting the time-dispersion error, but it allows us to use the maximum temporal interval under stability conditions; thus, its final computational efficiency would be higher than that of the traditional symplectic integration method for long-term simulations. With the aid of the ITDT, we can obtain much more accurate simulation results but with a lower computational cost.
Highly optimized fourth-order short-time approximation for path integrals.
Predescu, Cristian
2006-01-19
We derive a fourth-order short-time approximation for use in imaginary-time path-integral simulations. The short-time approximation converges for all continuous and bounded-from-below potentials, attains quartic order of convergence for sufficiently smooth potentials, and utilizes statistically independent random variables for its construction. These properties recommend the approximation as a natural replacement of the trapezoidal Trotter-Suzuki approximation for physical systems with continuous distributions. PMID:16471584
A Novel Reconstruction Framework for Time-Encoded Signals with Integrate-and-Fire Neurons.
Florescu, Dorian; Coca, Daniel
2015-09-01
Integrate-and-fire neurons are time encoding machines that convert the amplitude of an analog signal into a nonuniform, strictly increasing sequence of spike times. Under certain conditions, the encoded signals can be reconstructed from the nonuniform spike time sequences using a time decoding machine. Time encoding and time decoding methods have been studied using the nonuniform sampling theory for band-limited spaces, as well as for generic shift-invariant spaces. This letter proposes a new framework for studying IF time encoding and decoding by reformulating the IF time encoding problem as a uniform sampling problem. This framework forms the basis for two new algorithms for reconstructing signals from spike time sequences. We demonstrate that the proposed reconstruction algorithms are faster, and thus better suited for real-time processing, while providing a similar level of accuracy, compared to the standard reconstruction algorithm. PMID:26161820
An integrated software solution for real-time PCR analysis based on microfluidic biochip
NASA Astrophysics Data System (ADS)
Wang, Qinghui; Gong, Haiqing
2003-04-01
In this paper, we present an integrated and automated prototype system which has been developed for real-time polymerase chain reaction (PCR) analysis based on microfluidic PCR array chips. The system integrates the PCR thermal cycling and optical detection capabilities to enable real-time fluorescence imaging and image processing for data analysis. The main advantage of the system is that it provides a solution that can rapidly perform and evaluate PCR experiment simultaneously on microfluidic PCR array chips. The system has demonstrated fast and efficient on-chip real-time PCR analysis using human genomic DNA samples. The implementation of the system integration is a multi-thread Windows software with component structure which is written in Visual C++.
Applying an integrated neuro-expert system model in a real-time alarm processing system
NASA Astrophysics Data System (ADS)
Khosla, Rajiv; Dillon, Tharam S.
1993-03-01
In this paper we propose an integrated model which is derived from the combination of a generic neuro-expert system model, an object model, and unix operating system process (UOSP) model. This integrated model reflects the strengths of both artificial neural nets (ANNs) and expert systems (ESs). A formalism of ES object, ANN object, UOSP object, and problem domain object is used for developing a set of generic data structures and methods. These generic data structures and methods help us to build heterogeneous ES-ANN objects with uniform communication interface. The integrated model is applied in a real-time alarm processing system for a non-trivial terminal power station. It is shown how features like hierarchical/distributed ES/ANN objects, inter process communication, and fast concurrent execution help to cope with real-time system constraints like, continuity, data variability, and fast response time.
NASA Astrophysics Data System (ADS)
Mor, I.; Vartsky, D.; Dangendorf, V.; Bar, D.; Feldman, G.; Goldberg, M. B.; Tittelmeier, K.; Bromberger, B.; Brandis, M.; Weierganz, M.
2013-11-01
The Time-Resolved Integrative Optical Neutron (TRION) detector was developed for Fast Neutron Resonance Radiography (FNRR), a fast-neutron transmission imaging method that exploits characteristic energy-variations of the total scattering cross-section in the En = 1-10 MeV range to detect specific elements within a radiographed object. As opposed to classical event-counting time of flight (ECTOF), it integrates the detector signal during a well-defined neutron Time of Flight window corresponding to a pre-selected energy bin, e.g., the energy-interval spanning a cross-section resonance of an element such as C, O and N. The integrative characteristic of the detector permits loss-free operation at very intense, pulsed neutron fluxes, at a cost however, of recorded temporal resolution degradation This work presents a theoretical and experimental evaluation of detector related parameters which affect temporal resolution of the TRION system.
Non-electrical-power temperature-time integrating sensor for RFID based on microfluidics
NASA Astrophysics Data System (ADS)
Schneider, Mike; Hoffmann, Martin
2011-06-01
The integration of RFID tags into packages offers the opportunity to combine logistic advantages of the technology with monitoring different parameters from inside the package at the same time. An essential demand for enhanced product safety especially in pharmacy or food industry is the monitoring of the time-temperature-integral. Thus, completely passive time-temperature-integrators (TTI) requiring no battery, microprocessor nor data logging devices are developed. TTI representing the sterilization process inside an autoclave system is a demanding challenge: a temperature of at least 120 °C have to be maintained over 45 minutes to assure that no unwanted organism remains. Due to increased temperature, the viscosity of a fluid changes and thus the speed of the fluid inside the channel increases. The filled length of the channel represents the time temperature integral affecting the system. Measurements as well as simulations allow drawing conclusions about the influence of the geometrical parameters of the system and provide the possibility of adaptation. Thus a completely passive sensor element for monitoring an integral parameter with waiving of external electrical power supply and data processing technology is demonstrated. Furthermore, it is shown how to adjust the specific TTI parameters of the sensor to different applications and needs by modifying the geometrical parameters of the system.
Two-time coherence of pulse trains and the integrated degree of temporal coherence.
Dutta, Rahul; Friberg, Ari T; Genty, Göery; Turunen, Jari
2015-09-01
We examine the temporal coherence properties of trains of nonidentical short optical pulses in the framework of the second-order coherence theory of nonstationary light. Considering Michelson's interferometric measurement of temporal coherence, we demonstrate that time-resolved interferograms reveal the full two-time temporal coherence function of the partially coherent pulse train. We also show that the result given by the time-integrated Michelson interferogram equals the true degree of temporal coherence only when the pulse train is quasi-stationary, i.e., the coherence time is a small fraction of the pulse duration. True two-time and integrated coherence functions produced by specific models representing perturbed trains of mode-locked pulses and supercontinuum pulse trains produced in nonlinear fibers are illustrated. PMID:26367430
NASA Astrophysics Data System (ADS)
Baiardi, Alberto; Barone, Vincenzo; Biczysko, Malgorzata; Bloino, Julien
2014-06-01
Two parallel theories including Franck-Condon, Herzberg-Teller and Duschinsky (i.e., mode mixing) effects, allowing different approximations for the description of excited state PES have been developed in order to simulate realistic, asymmetric, electronic spectra line-shapes taking into account the vibrational structure: the so-called sum-over-states or time-independent (TI) method and the alternative time-dependent (TD) approach, which exploits the properties of the Fourier transform. The integrated TI-TD procedure included within a general purpose QM code [1,2], allows to compute one photon absorption, fluorescence, phosphorescence, electronic circular dichroism, circularly polarized luminescence and resonance Raman spectra. Combining both approaches, which use a single set of starting data, permits to profit from their respective advantages and minimize their respective limits: the time-dependent route automatically includes all vibrational states and, possibly, temperature effects, while the time-independent route allows to identify and assign single vibronic transitions. Interpretation, analysis and assignment of experimental spectra based on integrated TI-TD vibronic computations will be illustrated for challenging cases of medium-sized open-shell systems in the gas and condensed phases with inclusion of leading anharmonic effects. 1. V. Barone, A. Baiardi, M. Biczysko, J. Bloino, C. Cappelli, F. Lipparini Phys. Chem. Chem. Phys, 14, 12404, (2012) 2. A. Baiardi, V. Barone, J. Bloino J. Chem. Theory Comput., 9, 4097-4115 (2013)
Time integration algorithms for the two-dimensional Euler equations on unstructured meshes
NASA Technical Reports Server (NTRS)
Slack, David C.; Whitaker, D. L.; Walters, Robert W.
1994-01-01
Explicit and implicit time integration algorithms for the two-dimensional Euler equations on unstructured grids are presented. Both cell-centered and cell-vertex finite volume upwind schemes utilizing Roe's approximate Riemann solver are developed. For the cell-vertex scheme, a four-stage Runge-Kutta time integration, a fourstage Runge-Kutta time integration with implicit residual averaging, a point Jacobi method, a symmetric point Gauss-Seidel method and two methods utilizing preconditioned sparse matrix solvers are presented. For the cell-centered scheme, a Runge-Kutta scheme, an implicit tridiagonal relaxation scheme modeled after line Gauss-Seidel, a fully implicit lower-upper (LU) decomposition, and a hybrid scheme utilizing both Runge-Kutta and LU methods are presented. A reverse Cuthill-McKee renumbering scheme is employed for the direct solver to decrease CPU time by reducing the fill of the Jacobian matrix. A comparison of the various time integration schemes is made for both first-order and higher order accurate solutions using several mesh sizes, higher order accuracy is achieved by using multidimensional monotone linear reconstruction procedures. The results obtained for a transonic flow over a circular arc suggest that the preconditioned sparse matrix solvers perform better than the other methods as the number of elements in the mesh increases.
Timing of Formal Phase Safety Reviews for Large-Scale Integrated Hazard Analysis
NASA Technical Reports Server (NTRS)
Massie, Michael J.; Morris, A. Terry
2010-01-01
Integrated hazard analysis (IHA) is a process used to identify and control unacceptable risk. As such, it does not occur in a vacuum. IHA approaches must be tailored to fit the system being analyzed. Physical, resource, organizational and temporal constraints on large-scale integrated systems impose additional direct or derived requirements on the IHA. The timing and interaction between engineering and safety organizations can provide either benefits or hindrances to the overall end product. The traditional approach for formal phase safety review timing and content, which generally works well for small- to moderate-scale systems, does not work well for very large-scale integrated systems. This paper proposes a modified approach to timing and content of formal phase safety reviews for IHA. Details of the tailoring process for IHA will describe how to avoid temporary disconnects in major milestone reviews and how to maintain a cohesive end-to-end integration story particularly for systems where the integrator inherently has little to no insight into lower level systems. The proposal has the advantage of allowing the hazard analysis development process to occur as technical data normally matures.
NASA Astrophysics Data System (ADS)
Patacchini, L.; Hutchinson, I. H.
2009-04-01
A new explicit time-reversible orbit integrator for the equations of motion in a static homogeneous magnetic field - called Cyclotronic integrator - is presented. Like Spreiter and Walter's Taylor expansion algorithm, for sufficiently weak electric field gradients this second order method does not require a fine resolution of the Larmor motion; it has however the essential advantage of being symplectic, hence time-reversible. The Cyclotronic integrator is only subject to a linear stability constraint ( ΩΔ t < π, Ω being the Larmor angular frequency), and is therefore particularly suitable to electrostatic Particle In Cell codes with uniform magnetic field where Ω is larger than any other characteristic frequency, yet a resolution of the particles' gyromotion is required. Application examples and a detailed comparison with the well-known (time-reversible) Boris algorithm are presented; it is in particular shown that implementation of the Cyclotronic integrator in the kinetic codes SCEPTIC and Democritus can reduce the cost of orbit integration by up to a factor of ten.
N1s and O1s double ionization of the NO and N2O molecules
NASA Astrophysics Data System (ADS)
Hedin, L.; Tashiro, M.; Linusson, P.; Eland, J. H. D.; Ehara, M.; Ueda, K.; Zhaunerchyk, V.; Karlsson, L.; Pernestâl, K.; Feifel, R.
2014-01-01
Single-site N1s and O1s double core ionisation of the NO and N2O molecules has been studied using a magnetic bottle many-electron coincidence time-of-flight spectrometer at photon energies of 1100 eV and 1300 eV. The double core hole energies obtained for NO are 904.8 eV (N1s-2) and 1179.4 eV (O1s-2). The corresponding energies obtained for N2O are 896.9 eV (terminal N1s-2), 906.5 eV (central N1s-2), and 1174.1 eV (O1s-2). The ratio between the double and single ionisation energies are in all cases close or equal to 2.20. Large chemical shifts are observed in some cases which suggest that reorganisation of the electrons upon the double ionization is significant. Δ-self-consistent field and complete active space self-consistent field (CASSCF) calculations were performed for both molecules and they are in good agreement with these results. Auger spectra of N2O, associated with the decay of the terminal and central N1s-2 as well as with the O1s-2 dicationic states, were extracted showing the two electrons emitted as a result of filling the double core holes. The spectra, which are interpreted using CASSCF and complete active space configuration interaction calculations, show atomic-like character. The cross section ratio between double and single core hole creation was estimated as 1.6 × 10-3 for nitrogen at 1100 eV and as 1.3 × 10-3 for oxygen at 1300 eV.
N1s and O1s double ionization of the NO and N{sub 2}O molecules
Hedin, L.; Zhaunerchyk, V.; Karlsson, L.; Pernestål, K.; Feifel, R.; Tashiro, M.; Ehara, M.; Linusson, P.; Eland, J. H. D.; Ueda, K.
2014-01-28
Single-site N1s and O1s double core ionisation of the NO and N{sub 2}O molecules has been studied using a magnetic bottle many-electron coincidence time-of-flight spectrometer at photon energies of 1100 eV and 1300 eV. The double core hole energies obtained for NO are 904.8 eV (N1s{sup −2}) and 1179.4 eV (O1s{sup −2}). The corresponding energies obtained for N{sub 2}O are 896.9 eV (terminal N1s{sup −2}), 906.5 eV (central N1s{sup −2}), and 1174.1 eV (O1s{sup −2}). The ratio between the double and single ionisation energies are in all cases close or equal to 2.20. Large chemical shifts are observed in some cases which suggest that reorganisation of the electrons upon the double ionization is significant. Δ-self-consistent field and complete active space self-consistent field (CASSCF) calculations were performed for both molecules and they are in good agreement with these results. Auger spectra of N{sub 2}O, associated with the decay of the terminal and central N1s{sup −2} as well as with the O1s{sup −2} dicationic states, were extracted showing the two electrons emitted as a result of filling the double core holes. The spectra, which are interpreted using CASSCF and complete active space configuration interaction calculations, show atomic-like character. The cross section ratio between double and single core hole creation was estimated as 1.6 × 10{sup −3} for nitrogen at 1100 eV and as 1.3 × 10{sup −3} for oxygen at 1300 eV.
N1s and O1s double ionization of the NO and N2O molecules.
Hedin, L; Tashiro, M; Linusson, P; Eland, J H D; Ehara, M; Ueda, K; Zhaunerchyk, V; Karlsson, L; Pernestål, K; Feifel, R
2014-01-28
Single-site N1s and O1s double core ionisation of the NO and N2O molecules has been studied using a magnetic bottle many-electron coincidence time-of-flight spectrometer at photon energies of 1100 eV and 1300 eV. The double core hole energies obtained for NO are 904.8 eV (N1s(-2)) and 1179.4 eV (O1s(-2)). The corresponding energies obtained for N2O are 896.9 eV (terminal N1s(-2)), 906.5 eV (central N1s(-2)), and 1174.1 eV (O1s(-2)). The ratio between the double and single ionisation energies are in all cases close or equal to 2.20. Large chemical shifts are observed in some cases which suggest that reorganisation of the electrons upon the double ionization is significant. Δ-self-consistent field and complete active space self-consistent field (CASSCF) calculations were performed for both molecules and they are in good agreement with these results. Auger spectra of N2O, associated with the decay of the terminal and central N1s(-2) as well as with the O1s(-2) dicationic states, were extracted showing the two electrons emitted as a result of filling the double core holes. The spectra, which are interpreted using CASSCF and complete active space configuration interaction calculations, show atomic-like character. The cross section ratio between double and single core hole creation was estimated as 1.6 × 10(-3) for nitrogen at 1100 eV and as 1.3 × 10(-3) for oxygen at 1300 eV. PMID:25669525
A study of pile-up in integrated time-correlated single photon counting systems.
Arlt, Jochen; Tyndall, David; Rae, Bruce R; Li, David D-U; Richardson, Justin A; Henderson, Robert K
2013-10-01
Recent demonstration of highly integrated, solid-state, time-correlated single photon counting (TCSPC) systems in CMOS technology is set to provide significant increases in performance over existing bulky, expensive hardware. Arrays of single photon single photon avalanche diode (SPAD) detectors, timing channels, and signal processing can be integrated on a single silicon chip with a degree of parallelism and computational speed that is unattainable by discrete photomultiplier tube and photon counting card solutions. New multi-channel, multi-detector TCSPC sensor architectures with greatly enhanced throughput due to minimal detector transit (dead) time or timing channel dead time are now feasible. In this paper, we study the potential for future integrated, solid-state TCSPC sensors to exceed the photon pile-up limit through analytic formula and simulation. The results are validated using a 10% fill factor SPAD array and an 8-channel, 52 ps resolution time-to-digital conversion architecture with embedded lifetime estimation. It is demonstrated that pile-up insensitive acquisition is attainable at greater than 10 times the pulse repetition rate providing over 60 dB of extended dynamic range to the TCSPC technique. Our results predict future CMOS TCSPC sensors capable of live-cell transient observations in confocal scanning microscopy, improved resolution of near-infrared optical tomography systems, and fluorescence lifetime activated cell sorting. PMID:24182099
A study of pile-up in integrated time-correlated single photon counting systems
NASA Astrophysics Data System (ADS)
Arlt, Jochen; Tyndall, David; Rae, Bruce R.; Li, David D.-U.; Richardson, Justin A.; Henderson, Robert K.
2013-10-01
Recent demonstration of highly integrated, solid-state, time-correlated single photon counting (TCSPC) systems in CMOS technology is set to provide significant increases in performance over existing bulky, expensive hardware. Arrays of single photon single photon avalanche diode (SPAD) detectors, timing channels, and signal processing can be integrated on a single silicon chip with a degree of parallelism and computational speed that is unattainable by discrete photomultiplier tube and photon counting card solutions. New multi-channel, multi-detector TCSPC sensor architectures with greatly enhanced throughput due to minimal detector transit (dead) time or timing channel dead time are now feasible. In this paper, we study the potential for future integrated, solid-state TCSPC sensors to exceed the photon pile-up limit through analytic formula and simulation. The results are validated using a 10% fill factor SPAD array and an 8-channel, 52 ps resolution time-to-digital conversion architecture with embedded lifetime estimation. It is demonstrated that pile-up insensitive acquisition is attainable at greater than 10 times the pulse repetition rate providing over 60 dB of extended dynamic range to the TCSPC technique. Our results predict future CMOS TCSPC sensors capable of live-cell transient observations in confocal scanning microscopy, improved resolution of near-infrared optical tomography systems, and fluorescence lifetime activated cell sorting.
Advanced receiver autonomous integrity monitoring (ARAIM) schemes with GNSS time offsets
NASA Astrophysics Data System (ADS)
Wu, Yun; Wang, Jinling; Jiang, Yiping
2013-07-01
Within the current Advanced Receiver Integrity Monitoring (ARAIM) scheme, the time offsets between different Global Navigation Satellite System (GNSS) constellations are estimated along with a position solution and the GNSS receiver clock error. This scheme is called the Time-offsets Estimated ARAIM, or the TOE ARAIM. In order to enhance the interoperability and compatibility between different constellations, the time offsets are expected to be broadcast to users in future multi-GNSS positioning and navigation applications. This paper describes two new ARAIM schemes to make use of the Broadcast Time Offsets (BTOs): Time Offset Observed ARAIM (TOO ARAIM) and Time Offset Synchronized ARAIM (TOS ARAIM). It has been shown that the VPL performances of these two new ARAIM schemes rely strongly on the accuracy of BTOs. By varying the error model of the BTOs, the simulation results also demonstrate that the proposed new TOO ARAIM scheme can outperform the existing TOE ARAIM scheme-even if the accuracy of BTOs for integrity is degraded to 4.5 m and the probability of a BTO fault is relaxed to 10-2 h-1. In addition, the new Time Offset Synchronized ARAIM scheme (TOS ARAIM) can also perform better than the existing TOE ARAIM scheme if the accuracy of BTOs for integrity can reach 0.75 m. As the TOO ARAIM also has a very relaxed requirement on BTOs and better VPL performance, the TOO ARAIM is regarded as a superior ARAIM scheme for multi-GNSS with BTOs available.
Time and space integrating acousto-optic folded spectrum processing for SETI
NASA Technical Reports Server (NTRS)
Wagner, K.; Psaltis, D.
1986-01-01
Time and space integrating folded spectrum techniques utilizing acousto-optic devices (AOD) as 1-D input transducers are investigated for a potential application as wideband, high resolution, large processing gain spectrum analyzers in the search for extra-terrestrial intelligence (SETI) program. The space integrating Fourier transform performed by a lens channels the coarse spectral components diffracted from an AOD onto an array of time integrating narrowband fine resolution spectrum analyzers. The pulsing action of a laser diode samples the interferometrically detected output, aliasing the fine resolution components to baseband, as required for the subsequent charge coupled devices (CCD) processing. The raster scan mechanism incorporated into the readout of the CCD detector array is used to unfold the 2-D transform, reproducing the desired high resolution Fourier transform of the input signal.
Xiong, Z.; Tripp, A.C.
1994-12-31
This paper presents an integral equation algorithm for 3D EM modeling at high frequencies for applications in engineering an environmental studies. The integral equation method remains the same for low and high frequencies, but the dominant roles of the displacements currents complicate both numerical treatments and interpretations. With singularity extraction technique they successively extended the application of the Hankel filtering technique to the computation of Hankel integrals occurring in high frequency EM modeling. Time domain results are calculated from frequency domain results via Fourier transforms. While frequency domain data are not obvious for interpretations, time domain data show wave-like pictures that resemble seismograms. Both 1D and 3D numerical results show clearly the layer interfaces.
Time-Integrated Fluorescence Cumulant Analysis and Its Application in Living Cells
Wu, Bin; Singer, Robert H.; Mueller, Joachim D.
2014-01-01
Time-integrated fluorescence cumulant analysis (TIFCA) is a data analysis technique for fluorescence fluctuation spectroscopy (FFS) that extracts information from the cumulants of the integrated fluorescence intensity. It is the first exact theory that describes the effect of sampling time on FFS experiment. Rebinning of data to longer sampling times helps to increase the signal/noise ratio of the experimental cumulants of the photon counts. The sampling time dependence of the cumulants encodes both brightness and diffusion information of the sample. TIFCA analysis extracts this formation by fitting the cumulants to model functions. Generalization of TIFCA to multicolor FFS experiment is straightforward. Here, we present an overview of the theory, its implementation, as well as the benefits and requirements of TIFCA. The questions of why, when, and how to use TIFCA will be discussed. We give several examples of practical applications of TIFCA, particularly focused on measuring molecular interaction in living cells. PMID:23276537
Two-dimensional time-domain volume integral equations for scattering of inhomogeneous objects
NASA Astrophysics Data System (ADS)
Wang, Jianguo; Fan, Ruyu
2003-08-01
This paper proposes a time-domain volume integral equation based method for analyzing the transient scattering from a two-dimensional inhomogeneous cylinder by invoking the volume equivalence principle for both the transverse magnetic and electric cases. The cylinder is discretized into triangular cells, and the electric flux is chosen as the unknown. For the transverse magnetic case, the electric flux is defined on the surfaces of the triangles. For the transverse electric case, because of the electric charges induced inside and on the surface of the cylinder, the electric flux is defined on the edges of the triangles, and expanded in space in terms of two-dimensional surface roof-top basis functions. The time-domain volume integral equation is solved by using a marching-on-in-time scheme. Numerical results obtained using this method are in excellent agreement with the data obtained using the finite-difference time-domain method.
An Integral Method for Determining Induced Voltage in Time-Varying Wire Inductors
Fasenfest, B; White, D; Rockway, J
2005-05-27
This report documents the creation of software tools to model time-varying wire inductors. The class of inductors studied consists of arbitrary wire shapes in nonmagnetic material. When the wire structures are deformed, the inductance changes, and a voltage is induced. This voltage is of interest, for instance when the inductor is used to measure or sense a shockwave. An integral technique, which only requires integrating over the wire segments, is used to find the inductance at each time step, with backwards-difference approximations being used on successive time steps to determine the voltage. This method allows for arbitrary time-varying wire structures. It was tested for several canonical problems and used to model a double helix solenoid compressed by a shockwave.
Controlled time integration for the numerical simulation of meteor radar reflections
NASA Astrophysics Data System (ADS)
Räbinä, Jukka; Mönkölä, Sanna; Rossi, Tuomo; Markkanen, Johannes; Gritsevich, Maria; Muinonen, Karri
2016-07-01
We model meteoroids entering the Earth's atmosphere as objects surrounded by non-magnetized plasma, and consider efficient numerical simulation of radar reflections from meteors in the time domain. Instead of the widely used finite difference time domain method (FDTD), we use more generalized finite differences by applying the discrete exterior calculus (DEC) and non-uniform leapfrog-style time discretization. The computational domain is presented by convex polyhedral elements. The convergence of the time integration is accelerated by the exact controllability method. The numerical experiments show that our code is efficiently parallelized. The DEC approach is compared to the volume integral equation (VIE) method by numerical experiments. The result is that both methods are competitive in modelling non-magnetized plasma scattering. For demonstrating the simulation capabilities of the DEC approach, we present numerical experiments of radar reflections and vary parameters in a wide range.
The use of time-domain integral equations in electromagnetism problems
NASA Astrophysics Data System (ADS)
Berthon, A.; Vallet, E.
1984-10-01
The application of time-domain integral equations to the analysis of the scattering and propagation of EM fields is surveyed. Explicit iterative time-stepping procedures are developed for such problems as simple-conductor obstacles, one-dimensional obstacles, orifices, small obstacles, and media of finite conductivity (interface fields, reflection factors, and shielding problems). Numerical results for problems involving the interaction of a dipole field with various cylindrical obstacles are presented in graphs and diagrams.
Implicit integration of the time-dependent Ginzburg-Landau equations of superconductivity.
Gunter, D. O.; Kaper, H. G.; Leaf, G. K.; Mathematics and Computer Science
2002-05-17
This article is concerned with the integration of the time-dependent Ginzburg-Landau (TDGL) equations of superconductivity. Four algorithms, ranging from fully explicit to nonlinearly implicit, are presented and evaluated for stability, accuracy, and compute time. The benchmark problem for the evaluation is the equilibration of a vortex configuration in a superconductor that is embedded in a thin insulator and subject to an applied magnetic field.
ERIC Educational Resources Information Center
Harvard Family Research Project, 2010
2010-01-01
Across the country many schools and communities are trying to create and support efforts to institutionalize partnerships for learning, including those that rethink the use of time across the school day and year, and across the developmental continuum. Referred to by different terms--integrated, expanded, or complementary learning--the concept has…
Violation of Homogeneity of Variance Assumption in the Integrated Moving Averages Time Series Model.
ERIC Educational Resources Information Center
Gullickson, Arlen R.; And Others
This study is an analysis of the robustness of the Box-Tiao integrated moving averages model for analysis of time series quasi experiments. One of the assumptions underlying the Box-Tiao model is that all N values of alpha subscript t come from the same population which has a variance sigma squared. The robustness was studied only in terms of…
Mapping algorithm for 360-deg profilometry with time delayed integration imaging
NASA Astrophysics Data System (ADS)
Asundi, Anand K.; Zhou, Wensen
1999-02-01
A direct phase-to-radial distance mapping algorithm for 360 deg profilometry with time delay and integration imaging is presented. This method, based on an inherent mapping relationship, is capable of speedy and accurate measurement without the determination of any geometric parameter. The capability of the mapping algorithm is demonstrated by measuring a plane and a shoe.
Innovation Diffusion: A Deterministic Model of Space-Time Integration with Physical Analog
ERIC Educational Resources Information Center
Haynes, Kingsley E.; And Others
1977-01-01
Extends a fundamental temporal diffusion model to integrate space and time dimensions of innovation diffusion. Compares analogous developments in the physical sciences and argues that the proposed model may help link the concepts of catalysts in physical science diffusion processes to the role of change agents in social science systems. (Author/JG)
NASA Astrophysics Data System (ADS)
Bohlen, Thomas; Wittkamp, Florian
2016-03-01
We analyse the performance of a higher order accurate staggered viscoelastic time-domain finite-difference method, in which the staggered Adams-Bashforth (ABS) third-order and fourth-order accurate time integrators are used for temporal discretization. ABS is a multistep method that uses previously calculated wavefields to increase the order of accuracy in time. The analysis shows that the numerical dispersion is much lower than that of the widely used second-order leapfrog method. Numerical dissipation is introduced by the ABS method which is significantly smaller for fourth-order than third-order accuracy. In 1-D and 3-D simulation experiments, we verify the convincing improvements of simulation accuracy of the fourth-order ABS method. In a realistic elastic 3-D scenario, the computing time reduces by a factor of approximately 2.4, whereas the memory requirements increase by approximately a factor of 2.2. The ABS method thus provides an alternative strategy to increase the simulation accuracy in time by investing computer memory instead of computing time.
Model-integrated program synthesis environment for parallel/real-time image processing
NASA Astrophysics Data System (ADS)
Moore, Michael S.; Sztipanovitz, Janos; Karsai, Gabor; Nichols, James A.
1997-09-01
In this paper, it is shown that, through the use of model- integrated program synthesis (MIPS), parallel real-time implementations of image processing data flows can be synthesized from high level graphical specifications. The complex details in inherent to parallel and real-time software development become transparent to the programmer, enabling the cost-effective exploitation of parallel hardware for building more flexible and powerful real-time imaging systems. The model integrated real-time image processing system (MIRTIS) is presented as an example. MIRTIS employs the multigraph architecture (MGA), a framework and set of tools for building MIPS systems, to generate parallel real-time image processing software which runs under the control of a parallel run-time kernel on a network of Texas Instruments TMS320C40 DSPs (C40s). The MIRTIS models contain graphical declarations of the image processing computations to be performed, the available hardware resources, and the timing constraints of the application. The MIRTIS model interpreter performs the parallelization, scaling, and mapping of the computations to the resources automatically or determines that the timing constraints cannot be met with the available resources. MIRTIS is a clear example of how parallel real-time image processing systems can be built which are (1) cost-effectively programmable, (2) flexible, (3) scalable, and (4) built from commercial off-the-shelf (COTS) components.
Hartcher-O'Brien, Jess; Di Luca, Massimiliano; Ernst, Marc O
2014-01-01
Often multisensory information is integrated in a statistically optimal fashion where each sensory source is weighted according to its precision. This integration scheme isstatistically optimal because it theoretically results in unbiased perceptual estimates with the highest precisionpossible.There is a current lack of consensus about how the nervous system processes multiple sensory cues to elapsed time.In order to shed light upon this, we adopt a computational approach to pinpoint the integration strategy underlying duration estimationof audio/visual stimuli. One of the assumptions of our computational approach is that the multisensory signals redundantly specify the same stimulus property. Our results clearly show that despite claims to the contrary, perceived duration is the result of an optimal weighting process, similar to that adopted for estimates of space. That is, participants weight the audio and visual information to arrive at the most precise, single duration estimate possible. The work also disentangles how different integration strategies - i.e. consideringthe time of onset/offset ofsignals - might alter the final estimate. As such we provide the first concrete evidence of an optimal integration strategy in human duration estimates. PMID:24594578
Wang, Dong; Liu, Tao; Sun, Ximing; Zhong, Chongquan
2016-07-01
A discrete-time domain two-degree-of-freedom (2DOF) design method is proposed for integrating and unstable processes with time delay. Based on a 2DOF control structure recently developed, a controller is analytically designed in terms of the H2 optimal control performance specification for the set-point tracking, and another controller is derived by proposing the desired closed-loop transfer function for load disturbance rejection. Both controllers can be tuned relatively independent to realize control optimization. Analytical expression of the set-point response is given for quantitatively tuning the single adjustable parameter in the set-point tracking controller. At the meantime, sufficient and necessary conditions for holding robust stability of the closed-loop control system are established for tuning another adjustable parameter in the disturbance rejection controller, along with numerical tuning guidelines. Illustrative examples from the literature are used to demonstrate the effectiveness of the proposed method. PMID:27062021
Romá, Federico; Cugliandolo, Leticia F; Lozano, Gustavo S
2014-08-01
We introduce a numerical method to integrate the stochastic Landau-Lifshitz-Gilbert equation in spherical coordinates for generic discretization schemes. This method conserves the magnetization modulus and ensures the approach to equilibrium under the expected conditions. We test the algorithm on a benchmark problem: the dynamics of a uniformly magnetized ellipsoid. We investigate the influence of various parameters, and in particular, we analyze the efficiency of the numerical integration, in terms of the number of steps needed to reach a chosen long time with a given accuracy. PMID:25215839
NASA Astrophysics Data System (ADS)
Poon, H.; Ahmad, M. F.
This study presents an effective and robust time integration procedure for general anisotropic, thermal rheologically simple viscoelasticity, that is suitable for implementation in a broad spectrum of general purpose nonlinear finite element programs. It features a judicious choice of state variables which record the extent of inelastic flow (creep), a stable backward Euler integration step, and a consistent tangent operator. Numerical examples involving homogeneous stress states such as uniaxial tension and simple shear, and non-uniform stress states such as a beam under tip load, were carried out by incorporating the present scheme into a general purpose FEM package. Excellent agreement with analytical results is observed.
NASA Technical Reports Server (NTRS)
Park, K. C.; Belvin, W. Keith
1990-01-01
A general form for the first-order representation of the continuous second-order linear structural-dynamics equations is introduced to derive a corresponding form of first-order continuous Kalman filtering equations. Time integration of the resulting equations is carried out via a set of linear multistep integration formulas. It is shown that a judicious combined selection of computational paths and the undetermined matrices introduced in the general form of the first-order linear structural systems leads to a class of second-order discrete Kalman filtering equations involving only symmetric sparse N x N solution matrices.
NASA Technical Reports Server (NTRS)
Thompson, L. L.; Mccann, D. H.
1978-01-01
The visible focal plane of the Thematic Mapper, the next generation sensor system for application to earth resource survey, uses complex hybrid assembly techniques to interface silicon photodiodes to JFET preamplifiers. This complexity can be ameliorated by the use of a 20-channel time-delay-and-integration (TDI) CCD with nine stages of integration per channel. By going to a CCD array operating in a TDI mode, over 700 individual op amps can be replaced with only 48 op amps. Smooth spectral response and 70% quantum efficiency have been provided by using doped tin oxide gates over the imaging region.
Fully integrated time-to-amplitude converter for multidimensional TCSPC applications
NASA Astrophysics Data System (ADS)
Crotti, Matteo; Rech, Ivan; Ghioni, Massimo; Labanca, Ivan
2011-06-01
Over the past years an always growing interest has arisen about the measurement technique of time-correlated single photon counting (TCSPC), since it allows the analysis of extremely fast and weak light waveforms with a picoseconds resolution. Consequently, many applications exploiting TCSPC have been developing in several fields such as medicine and chemistry. Moreover, the use of multianode PMT and of single photon avalanche diode arrays led to the development of multichannel acquisition systems, employed in even more applications. Since TCSPC basically consists of the measurement of the arrival time of a photon, a high resolution and high linearity time measurement block is of the utmost importance, and in order to realize multidimensional systems, it has to be integrated to reduce both cost and area. We have designed and fabricated a 4 channel fully integrated time-to-amplitude converter (TAC), built in 0.35 μm Si-Ge technology, characterized by a very good time resolution (less than 50 ps), low differential nonlinearity (better than 2% peak-peak and less than 0.1% rms), high counting rate (16 MHz), low and constant power dissipation (50 mW), and low area occupation (2.58x1.28 mm2). Moreover our measurements show a very little crosstalk between the converters integrated on the same chip; this feature together with low power and low area make the fabricated converter suitable for parallelization, so it can be the starting point for future large scale multi-channel acquisition chains.
Tuning of IMC based PID controllers for integrating systems with time delay.
Kumar, D B Santosh; Padma Sree, R
2016-07-01
Design of Proportional Integral and Derivative (PID) controllers based on IMC principles for various types of integrating systems with time delay is proposed. PID parameters are given in terms of process model parameters and a tuning parameter. The tuning parameter is IMC filter time constant. In the present work, the IMC filter (Q) is chosen in such a manner that the order of the denominator of IMC controller is one less than the order of the numerator. The IMC filter time constant (λ) is tuned in such a way that a good compromise is made between performance and robustness for both servo and regulatory problems. To improve servo response of the controller a set point filter is designed such that the closed loop response is similar to that of first order plus time delay system. The proposed controller design method is applied to various transfer function models and to the non-linear model equations of jacketed CSTR to demonstrate its applicability and effectiveness. The performance of the proposed controller is compared with the recently reported methods in terms of IAE and ITAE. The smooth functioning of the controller is determined in terms of total variation and compared with recently reported methods. Simulation studies are carried out on various integrating systems with time delay to show the effectiveness and superiority of the proposed controllers. PMID:27087135
NASA Astrophysics Data System (ADS)
Kleinert, H.
1989-06-01
The Feynman formula, which expresses the time displacement amplitude > x b | exp (-t Ȟ) | x a< in terms of a path integral Π 1N (∫ dn) Π 1N+1 ( {∫ dp n}/{2π}) exp{Σ 1N [ ip n(x n-x n-1) - ɛH (p n, x n)]} with large N, does not exist for systems with Coulomb {-1}/{r} potential and gives incorrect threshold behaviours near centrifugal {1}/{r 2} or angular {1}/{sin2θ } barriers. We discuss the physical origin of this failure and propose an alternative well-defined path integral formula based on a family of amplitudes that is invariant under arbitrary local time reparametrizations. The time slicing with finite N breaks this invariance. For appropriate choices of the reparametrization function the fluctuations are stabilized and the new formula is applicable to all the above systems.
Note: Fully integrated 3.2 Gbps quantum random number generator with real-time extraction
NASA Astrophysics Data System (ADS)
Zhang, Xiao-Guang; Nie, You-Qi; Zhou, Hongyi; Liang, Hao; Ma, Xiongfeng; Zhang, Jun; Pan, Jian-Wei
2016-07-01
We present a real-time and fully integrated quantum random number generator (QRNG) by measuring laser phase fluctuations. The QRNG scheme based on laser phase fluctuations is featured for its capability of generating ultra-high-speed random numbers. However, the speed bottleneck of a practical QRNG lies on the limited speed of randomness extraction. To close the gap between the fast randomness generation and the slow post-processing, we propose a pipeline extraction algorithm based on Toeplitz matrix hashing and implement it in a high-speed field-programmable gate array. Further, all the QRNG components are integrated into a module, including a compact and actively stabilized interferometer, high-speed data acquisition, and real-time data post-processing and transmission. The final generation rate of the QRNG module with real-time extraction can reach 3.2 Gbps.
Note: Fully integrated 3.2 Gbps quantum random number generator with real-time extraction.
Zhang, Xiao-Guang; Nie, You-Qi; Zhou, Hongyi; Liang, Hao; Ma, Xiongfeng; Zhang, Jun; Pan, Jian-Wei
2016-07-01
We present a real-time and fully integrated quantum random number generator (QRNG) by measuring laser phase fluctuations. The QRNG scheme based on laser phase fluctuations is featured for its capability of generating ultra-high-speed random numbers. However, the speed bottleneck of a practical QRNG lies on the limited speed of randomness extraction. To close the gap between the fast randomness generation and the slow post-processing, we propose a pipeline extraction algorithm based on Toeplitz matrix hashing and implement it in a high-speed field-programmable gate array. Further, all the QRNG components are integrated into a module, including a compact and actively stabilized interferometer, high-speed data acquisition, and real-time data post-processing and transmission. The final generation rate of the QRNG module with real-time extraction can reach 3.2 Gbps. PMID:27475609
Molecular radiotherapy: The NUKFIT software for calculating the time-integrated activity coefficient
Kletting, P.; Schimmel, S.; Luster, M.; Kestler, H. A.; Hänscheid, H.; Fernández, M.; Lassmann, M.; Bröer, J. H.; Nosske, D.; Glatting, G.
2013-10-15
Purpose: Calculation of the time-integrated activity coefficient (residence time) is a crucial step in dosimetry for molecular radiotherapy. However, available software is deficient in that it is either not tailored for the use in molecular radiotherapy and/or does not include all required estimation methods. The aim of this work was therefore the development and programming of an algorithm which allows for an objective and reproducible determination of the time-integrated activity coefficient and its standard error.Methods: The algorithm includes the selection of a set of fitting functions from predefined sums of exponentials and the choice of an error model for the used data. To estimate the values of the adjustable parameters an objective function, depending on the data, the parameters of the error model, the fitting function and (if required and available) Bayesian information, is minimized. To increase reproducibility and user-friendliness the starting values are automatically determined using a combination of curve stripping and random search. Visual inspection, the coefficient of determination, the standard error of the fitted parameters, and the correlation matrix are provided to evaluate the quality of the fit. The functions which are most supported by the data are determined using the corrected Akaike information criterion. The time-integrated activity coefficient is estimated by analytically integrating the fitted functions. Its standard error is determined assuming Gaussian error propagation. The software was implemented using MATLAB.Results: To validate the proper implementation of the objective function and the fit functions, the results of NUKFIT and SAAM numerical, a commercially available software tool, were compared. The automatic search for starting values was successfully tested for reproducibility. The quality criteria applied in conjunction with the Akaike information criterion allowed the selection of suitable functions. Function fit
Utilizing real-time and near real-time data in the iNtegrated Space Weather Analysis System
NASA Astrophysics Data System (ADS)
Maddox, M. M.; Mullinix, R. E.; Rastaetter, L.; Pulkkinen, A.; Zheng, Y.; Berrios, D.; Hesse, M.; Kuznetsova, M. M.; Taktakishvili, A.; Chulaki, A.; Shim, J.; Bakshi, S. S.; Patel, K. D.; Jain, P.
2010-12-01
Access to near real-time and real-time space weather data is essential to accurately specifying and forecasting the space environment. The Space Weather Desk at NASA Goddard Space Flight Center's Space Weather Laboratory provides vital space weather forecasting services primarily to NASA robotic mission operators, as well as external space weather stakeholders including the Air Force Weather Agency. A key component in this activity is the iNtegrated Space Weather Analysis System which is a joint development project at NASA GSFC between the Space Weather Laboratory, Community Coordinated Modeling Center, Applied Engineering & Technology Directorate, and NASA HQ Office Of Chief Engineer. The iSWA system was developed to address technical challenges in acquiring and disseminating space weather environment information. A key design driver for the iSWA system was to generate and present vast amounts of space weather resources in an intuitive, user-configurable, and adaptable format - thus enabling users to respond to current and future space weather impacts as well as enabling post-impact analysis. Having access to near real-time and real-time data is essential to not only ensuring that relevant observational data is available for analysis - but also in ensuring that models can be driven with the requisite input parameters at proper and efficient temporal and spacial resolutions. The iSWA system currently manages over 250 unique near-real and real-time data feeds from various sources consisting of both observational and simulation data. A comprehensive suite of actionable space weather analysis tools and products are generated and provided utilizing a mixture of the ingested data - enabling new capabilities in quickly assessing past, present, and expected space weather effects. This paper will highlight current and future iSWA system capabilities and also discuss some of the challenges and lessons-learned in dealing with diverse real-time and near-real time space
NASA Astrophysics Data System (ADS)
Hoshiba, M.
2013-05-01
In this presentation, I propose a new approach for real-time prediction of seismic ground motion which is applicable to Earthquake Early Waning (EEW), in which hypocentral location and magnitude are not required. . Many methods of EEW are based on a network method in which hypocenter and magnitude (source parameters) are quickly determined, and then the ground motions are predicted, and warnings are issued depending on the strength of the predicted ground motion. In this method, it is necessary to determine the hypocenter and magnitude at first, and error of the source parameters leads directly to the error of the prediction. It is not easy to take the effects of rupture directivity and source extent into account, and it is impossible to fully reproduce the current wavefield from the interpreted source parameters. Time evolutional prediction is a method in which future wavefield is iteratively predicted from the wavefield at the certain time, that is u(x, t+Δt)=P(u(x, t)), where u is the wave motion at location x at lapse time t, and P is the prediction operator. Future wave motion, u(x, t+Δt), is predicted from the distribution of the current wave motion u(x, t) using P. For P, finite difference technique or boundary integral equation method, such as Kirchhoff integral, is used. Kirchhoff integral is qualitatively approximated by Huygens principle. The real time monitoring of wavefield are important for this method, but it is possible to predict ground motion without a hypocentral location and magnitude. In the time evolutional prediction, determination of detailed distribution of current wavefield is an important key, so that dense seismic observation network is required. Data assimilation is a technique to produce artificially denser network, which is widely used for numerical weather forecast and oceanography. Distribution of current wave motion is estimated from not only the current real observation of u(xi, t) where xi is the location of the i-th site, but
A new aerodynamic integral equation based on an acoustic formula in the time domain
NASA Technical Reports Server (NTRS)
Farassat, F.
1984-01-01
An aerodynamic integral equation for bodies moving at transonic and supersonic speeds is presented. Based on a time-dependent acoustic formula for calculating the noise emanating from the outer portion of a propeller blade travelling at high speed (the Ffowcs Williams-Hawking formulation), the loading terms and a conventional thickness source terms are retained. Two surface and three line integrals are employed to solve an equation for the loading noise. The near-field term is regularized using the collapsing sphere approach to obtain semiconvergence on the blade surface. A singular integral equation is thereby derived for the unknown surface pressure, and is amenable to numerical solutions using Galerkin or collocation methods. The technique is useful for studying the nonuniform inflow to the propeller.
Comparison of Fixed and Variable Time Step Trajectory Integration Methods for Cislunar Trajectories
NASA Technical Reports Server (NTRS)
Weeks, ichael W.; Thrasher, Stephen W.
2007-01-01
Due to the nonlinear nature of the Earth-Moon-Sun three-body problem and non-spherical gravity, CEV cislunar targeting algorithms will require many propagations in their search for a desired trajectory. For on-board targeting especially, the algorithm must have a simple, fast, and accurate propagator to calculate a trajectory with reasonable computation time, and still be robust enough to remain stable in the various flight regimes that the CEV will experience. This paper compares Cowell s method with a fourth-order Runge- Kutta integrator (RK4), Encke s method with a fourth-order Runge-Kutta- Nystr m integrator (RKN4), and a method known as Multi-Conic. Additionally, the study includes the Bond-Gottlieb 14-element method (BG14) and extends the investigation of Encke-Nystrom methods to integrators of higher order and with variable step size.
NASA Astrophysics Data System (ADS)
Manges, W. W.; Mallinak-Glassell, J. T.; Breeding, J. E.; Jansen, J. M., Jr.; Tate, R. M.; Bentz, R. R.
The Instrumentation and Controls Division at Oak Ridge National Laboratory recently developed and installed a large scale, real-time measurement system for the world's largest pressurized water tunnel. This water tunnel, the Large Cavitation Channel (LCC) provides a research and development facility for the study of acoustic phenomena to aid in model testing of new naval ship and submarine designs. The LCC design required the development of a near-field beamformer in addition to extending the range of real-time processing capability to frequencies unavailable at other facilities. The beamformer acquires and processes time-domain acoustic data at 9.5 MB/s from up to 45 hydrophones while performing 200 million floating-point operations per second, producing a time-integrated, spatially filtered, frequency-domain data set with improved signal-to-noise ratio. The acoustic processing software provides for the real-time analysis of acoustic data. Up to 128 facility sensors are sampled, time stamped, and stored at 600 kB/s. The system generates information for acoustic phenomena and facility measurements in real-time so that the operator can make facility adjustments to control the running equipment. This real-time control of facility conditions requires that the measurement system integrate facility and acoustic data for simultaneous display to the operator in engineering units via high-end workstations. A dual-host minicomputer configuration with high-end workstations connected via an Ethernet networking cluster controls and integrates measurement and display subsystems. The hardware and software architecture is described in this paper.
NASA Technical Reports Server (NTRS)
Hu, Fang Q.; Pizzo, Michelle E.; Nark, Douglas M.
2016-01-01
Based on the time domain boundary integral equation formulation of the linear convective wave equation, a computational tool dubbed Time Domain Fast Acoustic Scattering Toolkit (TD-FAST) has recently been under development. The time domain approach has a distinct advantage that the solutions at all frequencies are obtained in a single computation. In this paper, the formulation of the integral equation, as well as its stabilization by the Burton-Miller type reformulation, is extended to cases of a constant mean flow in an arbitrary direction. In addition, a "Source Surface" is also introduced in the formulation that can be employed to encapsulate regions of noise sources and to facilitate coupling with CFD simulations. This is particularly useful for applications where the noise sources are not easily described by analytical source terms. Numerical examples are presented to assess the accuracy of the formulation, including a computation of noise shielding by a thin barrier motivated by recent Historical Baseline F31A31 open rotor noise shielding experiments. Furthermore, spatial resolution requirements of the time domain boundary element method are also assessed using point per wavelength metrics. It is found that, using only constant basis functions and high-order quadrature for surface integration, relative errors of less than 2% may be obtained when the surface spatial resolution is 5 points-per-wavelength (PPW) or 25 points-per-wavelength squared (PPW2).
Time required to obtain representative point-integrated suspended sediment samples
NASA Astrophysics Data System (ADS)
Gitto, A.; Venditti, J. G.; Kostaschuk, R.; Church, M. A.
2013-12-01
Suspended sediment sampling by conventional bottle sampling methods remains one of the primary ways in which sediment input is measured for sediment budgets. Depth- and point-integrated methods are commonly assumed to accurately represent suspended sediment transport and to contain minimal error, however a recent study of depth-integrated sampling has identified considerable uncertainty between grain-size classes of multiple samples. The uncertainty surrounding point-integrated sampling methods is less well understood. This field study examines at-a-point variability in suspended sediment concentration, grain-size distribution, and grain-size moments to determine if traditional point-integrated methods accurately provide a representative sample of suspended sediment. Here, we present observations of suspended sediment from the sand bedded portion of the Fraser River at Mission, British Columbia, Canada, using a LISST laser-diffraction instrument. Measurements were obtained during the 2010 and 2013 freshet to address scales of sediment transport variability related to turbulence and hydraulic phenomena, respectively. Our observations indicate that the minimum sampling time to obtain representative indicators of suspended sediment transport ranges between 100 to 200 seconds. We are exploring the scales of variability embedded in the flow and the uncertainty in point-integrated sampling. Our goal is to understand the magnitude and the sources of error in suspended sediment measurements, to better understand the sources of uncertainty in sediment budgets.
Audio-visual integration of speech with time-varying sine wave speech replicas
NASA Astrophysics Data System (ADS)
Tuomainen, Jyrki; Andersen, Tobias; Tiippana, Kaisa; Sams, Mikko
2002-11-01
We tested whether listener's knowledge about the nature of the auditory stimuli had an effect on audio-visual (AV) integration of speech. First, subjects were taught to categorize two sine-wave (sw) replicas of the real speech tokens /omso/ and /onso/ into two arbitrary nonspeech categories without knowledge of the speech-like nature of the sounds. A test with congruent and incongruent AV-stimulus condition (together with auditory-only presentations of the sw stimuli) demonstrated no AV integration, but instead close to perfect categorization of stimuli in the two arbitrary categories according to the auditory presentation channel. Then, the same subjects (of which most were still under the impression that the sw-stimuli were nonspeech sounds) were taught to categorize the sw stimuli as /omso/ and /onso/, and again tested with the same AV stimuli as used in the nonspeech sw condition. This time, subjects showed highly reliable AV integration similar to integration obtained with real speech stimuli in a separate test. We suggest that AV integration only occurs when subject are in a so-called ''speech mode.''
Integrated photonic reservoir computing based on hierarchical time-multiplexing structure.
Zhang, Hong; Feng, Xue; Li, Boxun; Wang, Yu; Cui, Kaiyu; Liu, Fang; Dou, Weibei; Huang, Yidong
2014-12-15
An integrated photonic reservoir computing (RC) based on hierarchical time-multiplexing structure is proposed by numerical simulations. A micro-ring array (MRA) is employed as a typical time delay implementation of RC. At the output port of the MRA, a secondary time-multiplexing is achieved by multi-mode interference (MMI) splitter and delay line array. This hierarchical time-multiplexing structure can ensure a large reservoir size with fast processing speed. Simulation results indicate that the proposed RC system yields better performance than previously reported ones. The achieved normalized mean square error between the system output and target sequence are 0.5% and 2.7% for signal classification and chaotic time series prediction, respectively, while the sample rate is as high as 1.3 Gbps. PMID:25607084
First-passage times in integrate-and-fire neurons with stochastic thresholds
NASA Astrophysics Data System (ADS)
Braun, Wilhelm; Matthews, Paul C.; Thul, Rüdiger
2015-05-01
We consider a leaky integrate-and-fire neuron with deterministic subthreshold dynamics and a firing threshold that evolves as an Ornstein-Uhlenbeck process. The formulation of this minimal model is motivated by the experimentally observed widespread variation of neural firing thresholds. We show numerically that the mean first-passage time can depend nonmonotonically on the noise amplitude. For sufficiently large values of the correlation time of the stochastic threshold the mean first-passage time is maximal for nonvanishing noise. We provide an explanation for this effect by analytically transforming the original model into a first-passage-time problem for Brownian motion. This transformation also allows for a perturbative calculation of the first-passage-time histograms. In turn this provides quantitative insights into the mechanisms that lead to the nonmonotonic behavior of the mean first-passage time. The perturbation expansion is in excellent agreement with direct numerical simulations. The approach developed here can be applied to any deterministic subthreshold dynamics and any Gauss-Markov processes for the firing threshold. This opens up the possibility to incorporate biophysically detailed components into the subthreshold dynamics, rendering our approach a powerful framework that sits between traditional integrate-and-fire models and complex mechanistic descriptions of neural dynamics.
McLeod, R.; Hawkins, R.J.; Kallman, J.S.
1991-04-01
Interest has recently grown in applying microwave modeling techniques to optical circuit modeling. One of the simplest, yet most powerful, microwave simulation techniques is the finite-difference time-domain algorithm (FDTD). In this technique, the differential form of the time-domain Maxwell's equations are discretized and all derivatives are approximated as differences. Minor algebraic manipulations on the resulting equations produces a set of update equations that produce fields at a given time step from fields at the previous time step. The FDTD algorithm, then, is quite simple. Source fields are launched into the discrete grid by some means. The FDTD equations advance these fields in time. At the boundaries of the grid, special update equations called radiation conditions are applied that approximate a continuing, infinite space. Because virtually no assumptions are made in the development of the FDTD method, the algorithm is able to represent a wide-range of physical effects. Waves can propagate in any direction, multiple reflections within structures can cause resonances, multiple modes of various polarizations can be launched, each of which may generate within the device an infinite spectrum of bound and radiation modes. The ability to model these types of general physical effects is what makes the FDTD method interesting to the field of optics. In this paper, we discuss the application of the finite-difference time-domain technique to integrated optics. Animations will be shown of the simulations of a TE coupler, TM grating, and a TE integrated detector. 3 refs., 1 fig.
First-Passage and Residence Times in a Periodically Driven Integrate-and-Fire Model
NASA Astrophysics Data System (ADS)
Talkner, Peter; Schindler, Michael; Hänggi, Peter
2004-03-01
The stochastic integrate-and-fire model presents a simple description of the spiking behavior of neurons.In this model a neuron ``fires'' if an Ornstein-Uhlenbeck process crosses a prescribed threshold. After the firing the process is assumed to be in a refractory state, and from there it is put back into its initial, active state.This process can be characterized by the distribution of the first passage times of the threshold and by the residence times in the active states.We determined the distributions of these times for the integrate-and-fire model for short refractory times in the presence of a periodic signal.This is done by numerical solutions both of the respective Langevin equation and the equivalent Fokker-Planck equation. The results are compared with an approximate analytic theory. If the period of the signal is large compared to the relaxation time of the Ornstein-Uhlenbeck process and if the threshold is higher than a few times the noise strength we find theory and numerics to be in excellent agreement.
Gil, Yeongjoon; Li, Gang; Lee, Jungtae
2009-01-01
The anti-social behaviors of the people who are characteristic of abnormal action have seriously affected our society. Recent years, with the development of brain science, the features of human's abnormal action have been identified by means of the low frontal lobe activities. However, in many countries, the corresponding systems for identification and treatment are in an insufficient situation. Thus, in this paper, an integrated portable and real-time neurofeedback system assisted by EEG has been developed. The algorithm for this system has been developed and its performance has been verified by the fMRI experiment. Through the experiment, we ensured that the subjects controlled and checked their frontal lobe activities by themselves via the integrated real-time neurofeedback system. And then, the potential human's abnormal action could be not only early detected, but also eased via neurofeedback system. Therefore, we expected that our system can be more benefit to individuals and society. PMID:19963734
Time series autoregressive integrated moving average modeling of test-day milk yields of dairy ewes.
Macciotta, N P; Cappio-Borlino, A; Pulina, G
2000-05-01
Monthly test-day milk yields of 1200 dairy Sarda ewes were analyzed by time-series methods. Autocorrelation functions were calculated for lactations within parity classes and altitude of location of flocks. Spectral analysis of the successions of data was developed by Fourier transformation, and different Box-Jenkins autoregressive integrated moving average models were fitted. The separation of deterministic and stochastic components highlighted the autoregressive feature of milk production pattern. The forecasting power of autoregressive integrated moving average models was tested by predicting total milk production for a standardized lactation length of 225 d from only a few test-day records. Results indicated a greater forecasting capacity in comparison with standard methods and suggested further development of time-series analysis for studying lactation curves with more sophisticated methods, such as wavelet decomposition and neural network models. PMID:10821585
50 Gbit/s real-time test environment for integrated photonic DQPSK receivers
NASA Astrophysics Data System (ADS)
Föhn, T.; Fischer, C.; Berroth, M.
2014-11-01
In this paper an FPGA-based test system for high-speed transmission experiments with integrated photonic receivers is presented. Pseudorandom binary sequences are generated inside the FPGA and encoded as either differential quadrature phase shift keying (DQPSK) or quadrature phase shift keying (QPSK) signals. The DQPSK encoder uses a 64-fold parallel-prefix-layers architecture for real-time operation which allows for a maximum internal encoder data rate of 64 Gbit/s. Two-fold parallel data streams of I and Q signals suitable for driving an optical IQ-modulator can be transmitted and received by four 12.5 Gbit/s transceivers. Integrated bit error testers are used to determine bit error rates in real-time.
Optimal generalized multistep integration formulae for real-time digital simulation
NASA Technical Reports Server (NTRS)
Moerder, D. D.; Halyo, N.
1985-01-01
The problem of discretizing a dynamical system for real-time digital simulation is considered. Treating the system and its simulation as stochastic processes leads to a statistical characterization of simulator fidelity. A plant discretization procedure based on an efficient matrix generalization of explicit linear multistep discrete integration formulae is introduced, which minimizes a weighted sum of the mean squared steady-state and transient error between the system and simulator outputs.
Different time slices for different degrees of freedom in Feynman path integration
NASA Astrophysics Data System (ADS)
Li, Yimin; Miller, William H.
2005-01-01
A general scheme is presented for using different numbers of 'time slices' for different degrees of freedom in a path integral evaluation of the Boltzmann operator for a large molecular system. This will be particularly useful, for example, in evaluating the 'quantum instanton' rate constant [cf. W.H. Miller, Y. Zhao, M. Ceotto, S. Yang. J. Chem. Phys., 119, 1329 (2003)] for H atom transfer reactions, or any applications involving atoms with largely differing masses.
Radar and satellite area-time-integral techniques for estimating convective precipitation
NASA Technical Reports Server (NTRS)
Smith, Paul L.; Johnson, L. Ronald; Vonder Haar, Thomas H.; Reinke, Don
1990-01-01
The application of the area-time-integral (ATI) method (Doneaud et al, 1984) to radar and satellite measurements is reviewed. Results are presented from the calculation of ATI values from radar observations based on low-elevation-angle and low-altitude CAPPI data. Also, results from a satellite ATI calculation using IR images from a GEO platform are given. The results suggest that the radar and satellite applications produce good consistency.
NASA Astrophysics Data System (ADS)
Bylaska, Eric J.; Weare, Jonathan Q.; Weare, John H.
2013-08-01
Parallel in time simulation algorithms are presented and applied to conventional molecular dynamics (MD) and ab initio molecular dynamics (AIMD) models of realistic complexity. Assuming that a forward time integrator, f (e.g., Verlet algorithm), is available to propagate the system from time ti (trajectory positions and velocities xi = (ri, vi)) to time ti + 1 (xi + 1) by xi + 1 = fi(xi), the dynamics problem spanning an interval from t0…tM can be transformed into a root finding problem, F(X) = [xi - f(x(i - 1)]i = 1, M = 0, for the trajectory variables. The root finding problem is solved using a variety of root finding techniques, including quasi-Newton and preconditioned quasi-Newton schemes that are all unconditionally convergent. The algorithms are parallelized by assigning a processor to each time-step entry in the columns of F(X). The relation of this approach to other recently proposed parallel in time methods is discussed, and the effectiveness of various approaches to solving the root finding problem is tested. We demonstrate that more efficient dynamical models based on simplified interactions or coarsening time-steps provide preconditioners for the root finding problem. However, for MD and AIMD simulations, such preconditioners are not required to obtain reasonable convergence and their cost must be considered in the performance of the algorithm. The parallel in time algorithms developed are tested by applying them to MD and AIMD simulations of size and complexity similar to those encountered in present day applications. These include a 1000 Si atom MD simulation using Stillinger-Weber potentials, and a HCl + 4H2O AIMD simulation at the MP2 level. The maximum speedup (serial execution time/parallel execution time) obtained by parallelizing the Stillinger-Weber MD simulation was nearly 3.0. For the AIMD MP2 simulations, the algorithms achieved speedups of up to 14.3. The parallel in time algorithms can be implemented in a distributed computing
Bylaska, Eric J.; Weare, Jonathan Q.; Weare, John H.
2013-08-21
Parallel in time simulation algorithms are presented and applied to conventional molecular dynamics (MD) and ab initio molecular dynamics (AIMD) models of realistic complexity. Assuming that a forward time integrator, f (e.g., Verlet algorithm), is available to propagate the system from time t{sub i} (trajectory positions and velocities x{sub i} = (r{sub i}, v{sub i})) to time t{sub i+1} (x{sub i+1}) by x{sub i+1} = f{sub i}(x{sub i}), the dynamics problem spanning an interval from t{sub 0}…t{sub M} can be transformed into a root finding problem, F(X) = [x{sub i} − f(x{sub (i−1})]{sub i} {sub =1,M} = 0, for the trajectory variables. The root finding problem is solved using a variety of root finding techniques, including quasi-Newton and preconditioned quasi-Newton schemes that are all unconditionally convergent. The algorithms are parallelized by assigning a processor to each time-step entry in the columns of F(X). The relation of this approach to other recently proposed parallel in time methods is discussed, and the effectiveness of various approaches to solving the root finding problem is tested. We demonstrate that more efficient dynamical models based on simplified interactions or coarsening time-steps provide preconditioners for the root finding problem. However, for MD and AIMD simulations, such preconditioners are not required to obtain reasonable convergence and their cost must be considered in the performance of the algorithm. The parallel in time algorithms developed are tested by applying them to MD and AIMD simulations of size and complexity similar to those encountered in present day applications. These include a 1000 Si atom MD simulation using Stillinger-Weber potentials, and a HCl + 4H{sub 2}O AIMD simulation at the MP2 level. The maximum speedup ((serial execution time)/(parallel execution time) ) obtained by parallelizing the Stillinger-Weber MD simulation was nearly 3.0. For the AIMD MP2 simulations, the algorithms achieved speedups of up
Balistrieri, Laurie S.; Nimick, David A.; Mebane, Christopher A.
2012-01-01
Evaluating water quality and the health of aquatic organisms is challenging in systems with systematic diel (24 h) or less predictable runoff-induced changes in water composition. To advance our understanding of how to evaluate environmental health in these dynamic systems, field studies of diel cycling were conducted in two streams (Silver Bow Creek and High Ore Creek) affected by historical mining activities in southwestern Montana. A combination of sampling and modeling tools was used to assess the toxicity of metals in these systems. Diffusive Gradients in Thin Films (DGT) samplers were deployed at multiple time intervals during diel sampling to confirm that DGT integrates time-varying concentrations of dissolved metals. Site specific water compositions, including time-integrated dissolved metal concentrations determined from DGT, a competitive, multiple-toxicant biotic ligand model, and the Windemere Humic Aqueous Model Version 6.0 (WHAM VI) were used to determine the equilibrium speciation of dissolved metals and biotic ligands. The model results were combined with previously collected toxicity data on cutthroat trout to derive a relationship that predicts the relative survivability of these fish at a given site. This integrative approach may prove useful for assessing water quality and toxicity of metals to aquatic organisms in dynamic systems and evaluating whether potential changes in environmental health of aquatic systems are due to anthropogenic activities or natural variability.
Focusing of synthetic aperture radar ocean images with long integration times
NASA Astrophysics Data System (ADS)
Kasilingam, Dayalan P.; Hayt, David W.; Shemdin, Omar H.
1991-09-01
Synthetic aperture radar (SAR) images obtained in the SAR and X Band Ocean Nonlinearities: Chesapeake Light Tower (SAXON:CLT) experiment are processed with long integration times (6 s) and analyzed to study the effects of focusing. Two images with near-azimuth-traveling waves were chosen for the study. The first image consists of relatively short wavelength wind waves traveling in the same general direction as the aircraft. The second image consists of a long Atlantic swell traveling in the opposite direction to the aircraft. At these long integration times the image spectral intensities are found to be sensitive to the focus setting. The spectral intensity at the optimum focus is 400% of that at zero focus for the first image and 167% for the second image. The focusing curves for both images agree well with those predicted by a model developed by several groups and referred to here as the "consensus" model. This model predicts an optimum focus setting that is equal to one half of the effective phase speed of the dominant wave in the azimuth direction. The velocity bunching model underpredicts the optimum focus setting significantly. The study concludes that in long-integration-time SAR processing of surface waves, such as the spotlight mode, the image contrast is sensitively dependent on the focus setting and that the optimum focus setting is given by one half of the effective phase speed of the dominant surface wave.
A 7.5 ps single-shot precision integrated time counter with segmented delay line
NASA Astrophysics Data System (ADS)
Klepacki, K.; Szplet, R.; Pelka, R.
2014-03-01
This paper describes the design and test results of time interval counter featuring the single-shot precision of 7.5 ps root mean square (rms) and measurement range of 1 ms. These parameters have been achieved by combining direct counting method with a two-stage interpolation within a single clock period. Both stages of interpolation are based on the use of tapped delay lines stabilized by delay locked loop mechanism. In the first stage, a coarse resolution is obtained with the aid of high frequency multiphase clock, while in the second stage a sub-gate delay resolution is achieved with the use of differential delay line. To reduce the nonlinearities of conversion and to improve the precision of measurement, a novel segmented delay line is proposed. An important feature of this segmented delay line is partial overlapping of measurement range and resulting enhancement of both resolution and precision of time interval counter. The maximum integral nonlinearity error of the fine-stage interpolators does not exceed 16 ps and 14 ps in START and STOP interpolators, respectively. These errors have been identified by statistical calibration procedure and corrected to achieve single-shot precision better than 7.5 ps (rms). The time counter is integrated in a single ASIC (Application Specific Integrated Circuit) chip using a standard cost-effective 0.35 μm CMOS (Complementary Metal Oxide Semiconductor) process.
Development of the Semi-implicit Time Integration in KIM-SH
NASA Astrophysics Data System (ADS)
NAM, H.
2015-12-01
The Korea Institute of Atmospheric Prediction Systems (KIAPS) was founded in 2011 by the Korea Meteorological Administration (KMA) to develop Korea's own global Numerical Weather Prediction (NWP) system as nine year (2011-2019) project. The KIM-SH is a KIAPS integrated model-spectral element based in the HOMME. In KIM-SH, the explicit schemes are employed. We introduce the three- and two-time-level semi-implicit scheme in KIM-SH as the time integration. Explicit schemes however have a tendancy to be unstable and require very small timesteps while semi-implicit schemes are very stable and can have much larger timesteps.We define the linear and reference values, then by definition of semi-implicit scheme, we apply the linear solver as GMRES. The numerical results from experiments will be introduced with the current development status of the time integration in KIM-SH. Several numerical examples are shown to confirm the efficiency and reliability of the proposed schemes.
A 0.18-µm CMOS Array Sensor for Integrated Time-Resolved Fluorescence Detection
Huang, Ta-chien D.; Sorgenfrei, Sebastian; Gong, Ping; Levicky, Rastislav; Shepard, Kenneth L.
2010-01-01
This paper describes the design of an active, integrated CMOS sensor array for fluorescence applications which enables time-gated, time-resolved fluorescence spectroscopy. The 64-by-64 array is sensitive to photon densities as low as 8.8 × 106 photons/cm2 with 64-point averaging and, through a differential pixel design, has a measured impulse response of better than 800 ps. Applications include both active microarrays and high-frame-rate imagers for fluorescence lifetime imaging microscopy. PMID:20436922
Morrison, John L.
2001-04-24
Leaks are detected in a multi-layered geomembrane liner by a two-dimensional time domain reflectometry (TDR) technique. The TDR geomembrane liner is constructed with an electrically conductive detection layer positioned between two electrically non-conductive dielectric layers, which are each positioned between the detection layer and an electrically conductive reference layer. The integrity of the TDR geomembrane liner is determined by generating electrical pulses within the detection layer and measuring the time delay for any reflected electrical energy caused by absorption of moisture by a dielectric layer.
Procassini, R.J.; Birdsall, C.K.; Morse, E.C.; Cohen, B.I.
1988-01-01
Implicit time integration schemes allow for the use of larger time steps than conventional explicit methods, thereby extending the applicability of kinetic particle simulation methods. This paper will describe a study of the performance and optimization of two such direct implicit schemes, which are used to follow the trajectories of charged particles in an electrostatic, particle-in-cell plasma simulation code. The direct implicit method that was used for this study is an alternative to the moment-equation implicit method. 10 refs., 7 figs., 4 tabs.
Morris, John L.
1998-11-09
Leaks are detected in a multi-layered geomembrane liner by a two-dimensional time domain reflectometry (TDR) technique. The TDR geomembrane liner is constructed with an electrically conductive detection layer positioned between two electrically non-conductive dielectric layers, which are each positioned between the detection layer and an electrically conductive reference layer. The integrity of the TDR geomembrane liner is determined by generating electrical pulses within the detection layer and measuring the time delay for any reflected electrical energy caused by absorption of moisture by a dielectric layer.
Estimation of convective rain volumes utilizing the are-time-integral technique
NASA Technical Reports Server (NTRS)
Johnson, L. Ronald; Smith, Paul L.
1990-01-01
Interest in the possibility of developing useful estimates of convective rainfall with Area-Time Integral (ATI) methods is increasing. The basis of the ATI technique is the observed strong correlation between rainfall volumes and ATI values. This means that rainfall can be estimated by just determining the ATI values, if previous knowledge of the relationship to rain volume is available to calibrate the technique. Examples are provided of the application of the ATI approach to gage, radar, and satellite measurements. For radar data, the degree of transferability in time and among geographical areas is examined. Recent results on transferability of the satellite ATI calculations are presented.
NASA Astrophysics Data System (ADS)
Fortunati, Alessandro; Wiggins, Stephen
2014-09-01
The aim of this paper is to prove a Kolmogorov type result for a nearly integrable Hamiltonian, quadratic in the actions, with an aperiodic time dependence. The existence of a torus with a prefixed Diophantine frequency is shown in the forced system, provided that the perturbation is real-analytic and (exponentially) decaying with time. The advantage consists in the possibility to choose an arbitrarily small decaying coefficient consistently with the perturbation size. The proof, based on the Lie series formalism, is a generalization of a work by A. Giorgilli.
NASA Technical Reports Server (NTRS)
Sharafeddin, Omar A.; Judson, Richard S.; Kouri, Donald J.; Hoffman, David K.
1990-01-01
The novel wave-packet propagation scheme presented is based on the time-dependent form of the Lippman-Schwinger integral equation and does not require extensive matrix inversions, thereby facilitating application to systems in which some degrees of freedom express the potential in a basis expansion. The matrix to be inverted is a function of the kinetic energy operator, and is accordingly diagonal in a Bessel function basis set. Transition amplitudes for various orbital angular momentum quantum numbers are obtainable via either Fourier transform of the amplitude density from the time to the energy domain, or the direct analysis of the scattered wave packet.
Establishing more truth in space-time integration of surface turbulent heat fluxes
NASA Astrophysics Data System (ADS)
Gulev, Sergey; Belyaev, Konstantin
2016-04-01
Space-time integration of surface turbulent heat fluxes is important for obtaining area-averaged budget estimates and for producing climatologies of surface fluxes. Uncertainty of the integration or averaging of fluxes in space and in time are especially high when the data are sparse as in the case of the use of information from Voluntary Observing Ships (VOS) which are characterized by inhomogeneous sampling density in contrast to NWP products and satellite data sets. In order to minimize sampling impact onto local and larger scale surface flux averages we suggest an approach based upon analysis of surface fluxes in the coordinates of steering parameters (vertical surface temperature and humidity gradients on one hand and wind speed on the other). These variables are distributed according to the Modified Fisher-Tippett (MFT) distribution (temperature and humidity gradients) and Weibull distribution (wind speed) which imply a 2-dimentional distribution for the fluxes. Since the fluxes in these coordinates are determined in a unique manner (within a chosen bulk transfer algorithm), they can be easily integrated in the space of 2-dimentional distribution in order to get the averaged values dependent on the parameters of the MFT and Weibull distributions. Conceptually, the approach is similar to that oceanographers apply for analysing volumetric T,S-diagrams of water mass properties. We developed an algorithm for applying this approach and also provided the analysis of integrated surface fluxes for different regions of the North Atlantic for which heat flux estimates can be obtained from oceanographic cross-sections. Analysis was performed for the last 5 decades. 2-dimensitonal diagrams also make it possible to analyse temporal variability of integrated surface fluxes in the dimension of steering parameters and to further compare estimates with changes in the ocean heat content.
Bylaska, Eric J; Weare, Jonathan Q; Weare, John H
2013-08-21
Parallel in time simulation algorithms are presented and applied to conventional molecular dynamics (MD) and ab initio molecular dynamics (AIMD) models of realistic complexity. Assuming that a forward time integrator, f (e.g., Verlet algorithm), is available to propagate the system from time ti (trajectory positions and velocities xi = (ri, vi)) to time ti + 1 (xi + 1) by xi + 1 = fi(xi), the dynamics problem spanning an interval from t0[ellipsis (horizontal)]tM can be transformed into a root finding problem, F(X) = [xi - f(x(i - 1)]i = 1, M = 0, for the trajectory variables. The root finding problem is solved using a variety of root finding techniques, including quasi-Newton and preconditioned quasi-Newton schemes that are all unconditionally convergent. The algorithms are parallelized by assigning a processor to each time-step entry in the columns of F(X). The relation of this approach to other recently proposed parallel in time methods is discussed, and the effectiveness of various approaches to solving the root finding problem is tested. We demonstrate that more efficient dynamical models based on simplified interactions or coarsening time-steps provide preconditioners for the root finding problem. However, for MD and AIMD simulations, such preconditioners are not required to obtain reasonable convergence and their cost must be considered in the performance of the algorithm. The parallel in time algorithms developed are tested by applying them to MD and AIMD simulations of size and complexity similar to those encountered in present day applications. These include a 1000 Si atom MD simulation using Stillinger-Weber potentials, and a HCl + 4H2O AIMD simulation at the MP2 level. The maximum speedup (serial execution/timeparallel execution time) obtained by parallelizing the Stillinger-Weber MD simulation was nearly 3.0. For the AIMD MP2 simulations, the algorithms achieved speedups of up to 14.3. The parallel in time algorithms can be implemented in a
Night-Time Noise Index Based on the Integration of Awakening Potential
Tagusari, Junta; Takashima, Tomoya; Furukawa, Satoshi; Matsui, Toshihito
2016-01-01
Sleep disturbance induced by night-time noise is a serious environmental problem that can cause adverse health effects, such as hypertension and ischemic heart disease. Night-time noise indices are used to facilitate the enforcement of permitted noise levels during night-time. However, existing night-time noise indices, such as sound exposure level (SEL), maximum sound level (LAmax) and night equivalent level (Lnight) are selected mainly because of practical reasons. Therefore, this study proposes a noise index based on neurophysiological determinants of the awakening process. These determinants have revealed that the potential on awakening is likely integrated into the brainstem that dominates wakefulness and sleep. From this evidence, a night-time noise index, Nawake,year, was redefined based on the integration of the awakening potential unit (punit) estimated from the existing dose-response relationships of awakening. The newly-defined index considers the total number of awakenings and covers a wide-range and number of noise events. We also presented examples of its applicability to traffic noise. Although further studies are needed, it may reveal a reasonable dose-response relationship between sleep disturbance and adverse health effects and provide a consistent explanation for the risks of different sound sources where the characteristics of noise exposure are quite different. PMID:26938546
Note: Fully integrated time-to-amplitude converter in Si-Ge technology
NASA Astrophysics Data System (ADS)
Crotti, M.; Rech, I.; Ghioni, M.
2010-10-01
Over the past years an always growing interest has arisen about the measurement technique of time-correlated single photon counting TCSPC), since it allows the analysis of extremely fast and weak light waveforms with a picoseconds resolution. Consequently, many applications exploiting TCSPC have been developed in several fields such as medicine and chemistry. Moreover, the development of multianode PMT and of single photon avalanche diode arrays led to the realization of acquisition systems with several parallel channels to employ the TCSPC technique in even more applications. Since TCSPC basically consists of the measurement of the arrival time of a photon, the most important part of an acquisition chain is the time measurement block, which must have high resolution and low differential nonlinearity, and in order to realize multidimensional systems, it has to be integrated to reduce both cost and area. In this paper we present a fully integrated time-to-amplitude converter, built in 0.35 μm Si-Ge technology, characterized by a good time resolution (60 ps), low differential nonlinearity (better than 3% peak to peak), high counting rate (16 MHz), low and constant power dissipation (40 mW), and low area occupation (1.38×1.28 mm2).
Edwards, R.M.; Lee, K.Y.; Kumara, S.; Levine, S.H.
1989-01-01
An approach for an integrated real-time diagnostic system is being developed for inclusion as an integral part of a power plant automatic control system. In order to participate in control decisions and automatic closed loop operation, the diagnostic system must operate in real-time. Thus far, an expert system with real-time capabilities has been developed and installed on a subsystem at the Experimental Breeder Reactor (EBR-II) in Idaho, USA. Real-time simulation testing of advanced power plant concepts at the Pennsylvania State University has been developed and was used to support the expert system development and installation at EBR-II. Recently, the US National Science Foundation (NSF) and the US Department of Energy (DOE) have funded a Penn State research program to further enhance application of real-time diagnostic systems by pursuing implementation in a distributed power plant computer system including microprocessor based controllers. This paper summarizes past, current, planned, and possible future approaches to power plant diagnostic systems research at Penn State. 34 refs., 9 figs.
Time-reversal symmetric resolution of unity without background integrals in open quantum systems
Hatano, Naomichi; Ordonez, Gonzalo
2014-12-15
We present a new complete set of states for a class of open quantum systems, to be used in expansion of the Green’s function and the time-evolution operator. A remarkable feature of the complete set is that it observes time-reversal symmetry in the sense that it contains decaying states (resonant states) and growing states (anti-resonant states) parallelly. We can thereby pinpoint the occurrence of the breaking of time-reversal symmetry at the choice of whether we solve Schrödinger equation as an initial-condition problem or a terminal-condition problem. Another feature of the complete set is that in the subspace of the central scattering area of the system, it consists of contributions of all states with point spectra but does not contain any background integrals. In computing the time evolution, we can clearly see contribution of which point spectrum produces which time dependence. In the whole infinite state space, the complete set does contain an integral but it is over unperturbed eigenstates of the environmental area of the system and hence can be calculated analytically. We demonstrate the usefulness of the complete set by computing explicitly the survival probability and the escaping probability as well as the dynamics of wave packets. The origin of each term of matrix elements is clear in our formulation, particularly, the exponential decays due to the resonance poles.
Influence of time lag and noncolocation on integrated structural/control system designs
NASA Technical Reports Server (NTRS)
Manning, R. A.; Schmit, L. A.
1989-01-01
Recent research efforts have led to the development of simultaneous structural/control system design procedures. Absent in any of the work is the time delay present in the control system sensors and actuators and the computational time delay for synthesizing actuator commands from sensor measurements. Madden has shown that the time delay present in the control system can have profound effects on the resulting system performance and stability regardless of its source. In addition, many of the simultaneous structural/control system design procedures have used colocated sensors and actuators for implementation of the control system. In actual practice, colocation in not always possible. The issue of stability degradation when using noncolocated sensor and actuators was raised. The integrated structural/control system design procedure is extended to include the effects of time lag and noncolocation of sensors and actuators on the resulting optimum designs.
Integration of domain and resource-based reasoning for real-time control in dynamic environments
NASA Technical Reports Server (NTRS)
Morgan, Keith; Whitebread, Kenneth R.; Kendus, Michael; Cromarty, Andrew S.
1993-01-01
A real-time software controller that successfully integrates domain-based and resource-based control reasoning to perform task execution in a dynamically changing environment is described. The design of the controller is based on the concept of partitioning the process to be controlled into a set of tasks, each of which achieves some process goal. It is assumed that, in general, there are multiple ways (tasks) to achieve a goal. The controller dynamically determines current goals and their current criticality, choosing and scheduling tasks to achieve those goals in the time available. It incorporates rule-based goal reasoning, a TMS-based criticality propagation mechanism, and a real-time scheduler. The controller has been used to build a knowledge-based situation assessment system that formed a major component of a real-time, distributed, cooperative problem solving system built under DARPA contract. It is also being employed in other applications now in progress.
Bylaska, Eric J.; Weare, Jonathan Q.; Weare, John H.
2013-08-21
Parallel in time simulation algorithms are presented and applied to conventional molecular dynamics (MD) and ab initio molecular dynamics (AIMD) models of realistic complexity. Assuming that a forward time integrator, f , (e.g. Verlet algorithm) is available to propagate the system from time ti (trajectory positions and velocities xi = (ri; vi)) to time ti+1 (xi+1) by xi+1 = fi(xi), the dynamics problem spanning an interval from t0 : : : tM can be transformed into a root finding problem, F(X) = [xi - f (x(i-1)]i=1;M = 0, for the trajectory variables. The root finding problem is solved using a variety of optimization techniques, including quasi-Newton and preconditioned quasi-Newton optimization schemes that are all unconditionally convergent. The algorithms are parallelized by assigning a processor to each time-step entry in the columns of F(X). The relation of this approach to other recently proposed parallel in time methods is discussed and the effectiveness of various approaches to solving the root finding problem are tested. We demonstrate that more efficient dynamical models based on simplified interactions or coarsening time-steps provide preconditioners for the root finding problem. However, for MD and AIMD simulations such preconditioners are not required to obtain reasonable convergence and their cost must be considered in the performance of the algorithm. The parallel in time algorithms developed are tested by applying them to MD and AIMD simulations of size and complexity similar to those encountered in present day applications. These include a 1000 Si atom MD simulation using Stillinger-Weber potentials, and a HCl+4H2O AIMD simulation at the MP2 level. The maximum speedup obtained by parallelizing the Stillinger-Weber MD simulation was nearly 3.0. For the AIMD MP2 simulations the algorithms achieved speedups of up to 14.3. The parallel in time algorithms can be implemented in a distributed computing environment using very slow TCP/IP networks. Scripts
Higher-order time integration of Coulomb collisions in a plasma using Langevin equations
Dimits, A. M.; Cohen, B. I.; Caflisch, R. E.; Rosin, M. S.; Ricketson, L. F.
2013-02-08
The extension of Langevin-equation Monte-Carlo algorithms for Coulomb collisions from the conventional Euler-Maruyama time integration to the next higher order of accuracy, the Milstein scheme, has been developed, implemented, and tested. This extension proceeds via a formulation of the angular scattering directly as stochastic differential equations in the two fixed-frame spherical-coordinate velocity variables. Results from the numerical implementation show the expected improvement [O(Δt) vs. O(Δt^{1/2})] in the strong convergence rate both for the speed |v| and angular components of the scattering. An important result is that this improved convergence is achieved for the angular component of the scattering if and only if the “area-integral” terms in the Milstein scheme are included. The resulting Milstein scheme is of value as a step towards algorithms with both improved accuracy and efficiency. These include both algorithms with improved convergence in the averages (weak convergence) and multi-time-level schemes. The latter have been shown to give a greatly reduced cost for a given overall error level when compared with conventional Monte-Carlo schemes, and their performance is improved considerably when the Milstein algorithm is used for the underlying time advance versus the Euler-Maruyama algorithm. A new method for sampling the area integrals is given which is a simplification of an earlier direct method and which retains high accuracy. Lastly, this method, while being useful in its own right because of its relative simplicity, is also expected to considerably reduce the computational requirements for the direct conditional sampling of the area integrals that is needed for adaptive strong integration.
Integrating and Visualizing Tropical Cyclone Data Using the Real Time Mission Monitor
NASA Technical Reports Server (NTRS)
Goodman, H. Michael; Blakeslee, Richard; Conover, Helen; Hall, John; He, Yubin; Regner, Kathryn
2009-01-01
The Real Time Mission Monitor (RTMM) is a visualization and information system that fuses multiple Earth science data sources, to enable real time decision-making for airborne and ground validation experiments. Developed at the NASA Marshall Space Flight Center, RTMM is a situational awareness, decision-support system that integrates satellite imagery, radar, surface and airborne instrument data sets, model output parameters, lightning location observations, aircraft navigation data, soundings, and other applicable Earth science data sets. The integration and delivery of this information is made possible using data acquisition systems, network communication links, network server resources, and visualizations through the Google Earth virtual globe application. RTMM is extremely valuable for optimizing individual Earth science airborne field experiments. Flight planners, scientists, and managers appreciate the contributions that RTMM makes to their flight projects. A broad spectrum of interdisciplinary scientists used RTMM during field campaigns including the hurricane-focused 2006 NASA African Monsoon Multidisciplinary Analyses (NAMMA), 2007 NOAA-NASA Aerosonde Hurricane Noel flight, 2007 Tropical Composition, Cloud, and Climate Coupling (TC4), plus a soil moisture (SMAP-VEX) and two arctic research experiments (ARCTAS) in 2008. Improving and evolving RTMM is a continuous process. RTMM recently integrated the Waypoint Planning Tool, a Java-based application that enables aircraft mission scientists to easily develop a pre-mission flight plan through an interactive point-and-click interface. Individual flight legs are automatically calculated "on the fly". The resultant flight plan is then immediately posted to the Google Earth-based RTMM for interested scientists to view the planned flight track and subsequently compare it to the actual real time flight progress. We are planning additional capabilities to RTMM including collaborations with the Jet Propulsion
NASA Astrophysics Data System (ADS)
Wezka, K.; Galas, R.
2013-12-01
Ionospheric disturbances are characterized as fast and random variability in the ionosphere. Those phenomena are difficult to predict, detect and model. Occurrence of some strong ionospheric disturbances can cause, inter alia degradation and interruption of GNSS signals. Therefore they are especially harmful for real-time applications, as for example Precise Point Positioning (PPP) in real time, where one of the most important requirements is to ensure the high level of reliability. In such applications verification and confirmation of a high trust degree towards the estimated coordinates is a very critical issue. In one of the previous papers (K. Wezka, 2012 -Identification of system performance parameters and their usability) two sets of parameters have been proposed for enhance reliability of the PPP. The first one for data quality control (QC) of the raw GNSS observations and the second one for examination of the quality, robustness and performance of various processing approaches (strategies). To the second group the following parameters has been proposed: accuracy, precision, availability, integrity and convergence time. In consideration of perturbation of GNSS signal resulting from sudden ionospheric disturbances, one of the most important demands is effective autonomous integrity monitoring. The poster presents first preliminary results of the applicability of the proposed parameters in order to ensure the high level of reliability/integrity of GNSS observations and positioning results under the presence of strong ionospheric anomalies. The data-set from continuously operated GNSS station located at high latitude, where ionospheric disturbances occur more frequently, were used for the analysis. Various selected Receiver Autonomous Integrity Monitoring (RAIM) approaches for quality control of the GNSS observables are applied to the data sets recorded under different (low/quite and high) ionospheric activities. Based on those analyses the usability of the
Žarić, Gojko; Fraga González, Gorka; Tijms, Jurgen; van der Molen, Maurits W.; Blomert, Leo; Bonte, Milene
2015-01-01
A failure to build solid letter-speech sound associations may contribute to reading impairments in developmental dyslexia. Whether this reduced neural integration of letters and speech sounds changes over time within individual children and how this relates to behavioral gains in reading skills remains unknown. In this research, we examined changes in event-related potential (ERP) measures of letter-speech sound integration over a 6-month period during which 9-year-old dyslexic readers (n = 17) followed a training in letter-speech sound coupling next to their regular reading curriculum. We presented the Dutch spoken vowels /a/ and /o/ as standard and deviant stimuli in one auditory and two audiovisual oddball conditions. In one audiovisual condition (AV0), the letter “a” was presented simultaneously with the vowels, while in the other (AV200) it was preceding vowel onset for 200 ms. Prior to the training (T1), dyslexic readers showed the expected pattern of typical auditory mismatch responses, together with the absence of letter-speech sound effects in a late negativity (LN) window. After the training (T2), our results showed earlier (and enhanced) crossmodal effects in the LN window. Most interestingly, earlier LN latency at T2 was significantly related to higher behavioral accuracy in letter-speech sound coupling. On a more general level, the timing of the earlier mismatch negativity (MMN) in the simultaneous condition (AV0) measured at T1, significantly related to reading fluency at both T1 and T2 as well as with reading gains. Our findings suggest that the reduced neural integration of letters and speech sounds in dyslexic children may show moderate improvement with reading instruction and training and that behavioral improvements relate especially to individual differences in the timing of this neural integration. PMID:26157382
NASA Astrophysics Data System (ADS)
Min, Xiaoyi
This thesis first presents the study of the interaction of electromagnetic waves with three-dimensional heterogeneous, dielectric, magnetic, and lossy bodies by surface integral equation modeling. Based on the equivalence principle, a set of coupled surface integral equations is formulated and then solved numerically by the method of moments. Triangular elements are used to model the interfaces of the heterogeneous body, and vector basis functions are defined to expand the unknown current in the formulation. The validity of this formulation is verified by applying it to concentric spheres for which an exact solution exists. The potential applications of this formulation to a partially coated sphere and a homogeneous human body are discussed. Next, this thesis also introduces an efficient new set of integral equations for treating the scattering problem of a perfectly conducting body coated with a thin magnetically lossy layer. These electric field integral equations and magnetic field integral equations are numerically solved by the method of moments (MoM). To validate the derived integral equations, an alternative method to solve the scattering problem of an infinite circular cylinder coated with a thin magnetic lossy layer has also been developed, based on the eigenmode expansion. Results for the radar cross section and current densities via the MoM and the eigenmode expansion method are compared. The agreement is excellent. The finite difference time domain method is subsequently implemented to solve a metallic object coated with a magnetic thin layer and numerical results are compared with that by the MoM. Finally, this thesis presents an application of the finite-difference time-domain approach to the problem of electromagnetic receiving and scattering by a cavity -backed antenna situated on an infinite conducting plane. This application involves modifications of Yee's model, which applies the difference approximations of field derivatives to differential
Lee, Jae Young; Park, Jin Bae; Choi, Yoon Ho
2015-05-01
This paper focuses on a class of reinforcement learning (RL) algorithms, named integral RL (I-RL), that solve continuous-time (CT) nonlinear optimal control problems with input-affine system dynamics. First, we extend the concepts of exploration, integral temporal difference, and invariant admissibility to the target CT nonlinear system that is governed by a control policy plus a probing signal called an exploration. Then, we show input-to-state stability (ISS) and invariant admissibility of the closed-loop systems with the policies generated by integral policy iteration (I-PI) or invariantly admissible PI (IA-PI) method. Based on these, three online I-RL algorithms named explorized I-PI and integral Q -learning I, II are proposed, all of which generate the same convergent sequences as I-PI and IA-PI under the required excitation condition on the exploration. All the proposed methods are partially or completely model free, and can simultaneously explore the state space in a stable manner during the online learning processes. ISS, invariant admissibility, and convergence properties of the proposed methods are also investigated, and related with these, we show the design principles of the exploration for safe learning. Neural-network-based implementation methods for the proposed schemes are also presented in this paper. Finally, several numerical simulations are carried out to verify the effectiveness of the proposed methods. PMID:25163070
FPGA-Based Real-Time Embedded System for RISS/GPS Integrated Navigation
Abdelfatah, Walid Farid; Georgy, Jacques; Iqbal, Umar; Noureldin, Aboelmagd
2012-01-01
Navigation algorithms integrating measurements from multi-sensor systems overcome the problems that arise from using GPS navigation systems in standalone mode. Algorithms which integrate the data from 2D low-cost reduced inertial sensor system (RISS), consisting of a gyroscope and an odometer or wheel encoders, along with a GPS receiver via a Kalman filter has proved to be worthy in providing a consistent and more reliable navigation solution compared to standalone GPS receivers. It has been also shown to be beneficial, especially in GPS-denied environments such as urban canyons and tunnels. The main objective of this paper is to narrow the idea-to-implementation gap that follows the algorithm development by realizing a low-cost real-time embedded navigation system capable of computing the data-fused positioning solution. The role of the developed system is to synchronize the measurements from the three sensors, relative to the pulse per second signal generated from the GPS, after which the navigation algorithm is applied to the synchronized measurements to compute the navigation solution in real-time. Employing a customizable soft-core processor on an FPGA in the kernel of the navigation system, provided the flexibility for communicating with the various sensors and the computation capability required by the Kalman filter integration algorithm. PMID:22368460
Integration of real-time 3D capture, reconstruction, and light-field display
NASA Astrophysics Data System (ADS)
Zhang, Zhaoxing; Geng, Zheng; Li, Tuotuo; Pei, Renjing; Liu, Yongchun; Zhang, Xiao
2015-03-01
Effective integration of 3D acquisition, reconstruction (modeling) and display technologies into a seamless systems provides augmented experience of visualizing and analyzing real objects and scenes with realistic 3D sensation. Applications can be found in medical imaging, gaming, virtual or augmented reality and hybrid simulations. Although 3D acquisition, reconstruction, and display technologies have gained significant momentum in recent years, there seems a lack of attention on synergistically combining these components into a "end-to-end" 3D visualization system. We designed, built and tested an integrated 3D visualization system that is able to capture in real-time 3D light-field images, perform 3D reconstruction to build 3D model of the objects, and display the 3D model on a large autostereoscopic screen. In this article, we will present our system architecture and component designs, hardware/software implementations, and experimental results. We will elaborate on our recent progress on sparse camera array light-field 3D acquisition, real-time dense 3D reconstruction, and autostereoscopic multi-view 3D display. A prototype is finally presented with test results to illustrate the effectiveness of our proposed integrated 3D visualization system.
FPGA-based real-time embedded system for RISS/GPS integrated navigation.
Abdelfatah, Walid Farid; Georgy, Jacques; Iqbal, Umar; Noureldin, Aboelmagd
2012-01-01
Navigation algorithms integrating measurements from multi-sensor systems overcome the problems that arise from using GPS navigation systems in standalone mode. Algorithms which integrate the data from 2D low-cost reduced inertial sensor system (RISS), consisting of a gyroscope and an odometer or wheel encoders, along with a GPS receiver via a Kalman filter has proved to be worthy in providing a consistent and more reliable navigation solution compared to standalone GPS receivers. It has been also shown to be beneficial, especially in GPS-denied environments such as urban canyons and tunnels. The main objective of this paper is to narrow the idea-to-implementation gap that follows the algorithm development by realizing a low-cost real-time embedded navigation system capable of computing the data-fused positioning solution. The role of the developed system is to synchronize the measurements from the three sensors, relative to the pulse per second signal generated from the GPS, after which the navigation algorithm is applied to the synchronized measurements to compute the navigation solution in real-time. Employing a customizable soft-core processor on an FPGA in the kernel of the navigation system, provided the flexibility for communicating with the various sensors and the computation capability required by the Kalman filter integration algorithm. PMID:22368460
Freeman, Elliot D.; Ipser, Alberta; Palmbaha, Austra; Paunoiu, Diana; Brown, Peter; Lambert, Christian; Leff, Alex; Driver, Jon
2013-01-01
The sight and sound of a person speaking or a ball bouncing may seem simultaneous, but their corresponding neural signals are spread out over time as they arrive at different multisensory brain sites. How subjective timing relates to such neural timing remains a fundamental neuroscientific and philosophical puzzle. A dominant assumption is that temporal coherence is achieved by sensory resynchronisation or recalibration across asynchronous brain events. This assumption is easily confirmed by estimating subjective audiovisual timing for groups of subjects, which is on average similar across different measures and stimuli, and approximately veridical. But few studies have examined normal and pathological individual differences in such measures. Case PH, with lesions in pons and basal ganglia, hears people speak before seeing their lips move. Temporal order judgements (TOJs) confirmed this: voices had to lag lip-movements (by ∼200 msec) to seem synchronous to PH. Curiously, voices had to lead lips (also by ∼200 msec) to maximise the McGurk illusion (a measure of audiovisual speech integration). On average across these measures, PH's timing was therefore still veridical. Age-matched control participants showed similar discrepancies. Indeed, normal individual differences in TOJ and McGurk timing correlated negatively: subjects needing an auditory lag for subjective simultaneity needed an auditory lead for maximal McGurk, and vice versa. This generalised to the Stream–Bounce illusion. Such surprising antagonism seems opposed to good sensory resynchronisation, yet average timing across tasks was still near-veridical. Our findings reveal remarkable disunity of audiovisual timing within and between subjects. To explain this we propose that the timing of audiovisual signals within different brain mechanisms is perceived relative to the average timing across mechanisms. Such renormalisation fully explains the curious antagonistic relationship between disparate timing
Effect of Variations in IRU Integration Time Interval On Accuracy of Aqua Attitude Estimation
NASA Technical Reports Server (NTRS)
Natanson, G. A.; Tracewell, Dave
2003-01-01
During Aqua launch support, attitude analysts noticed several anomalies in Onboard Computer (OBC) rates and in rates computed by the ground Attitude Determination System (ADS). These included: 1) periodic jumps in the OBC pitch rate every 2 minutes; 2) spikes in ADS pitch rate every 4 minutes; 3) close agreement between pitch rates computed by ADS and those derived from telemetered OBC quaternions (in contrast to the step-wise pattern observed for telemetered OBC rates); 4) spikes of +/- 10 milliseconds in telemetered IRU integration time every 4 minutes (despite the fact that telemetered time tags of any two sequential IRU measurements were always 1 second apart from each other). An analysis presented in the paper explains this anomalous behavior by a small average offset of about 0.5 +/- 0.05 microsec in the time interval between two sequential accumulated angle measurements. It is shown that errors in the estimated pitch angle due to neglecting the aforementioned variations in the integration time interval by the OBC is within +/- 2 arcseconds. Ground attitude solutions are found to be accurate enough to see the effect of the variations on the accuracy of the estimated pitch angle.
Numerical evaluation of the Feynman integral-over-paths in real and imaginary-time
NASA Astrophysics Data System (ADS)
Register, L. F.; Stroscio, M. A.; Littlejohn, M. A.
New techniques are described for Monte Carlo evaluation of the propagation of quantum mechanical systems in both real and imaginary-time using the Feynman integral-over-paths formulation of quantum mechanics. For imaginary-time calculations path translation is used to augment the technique of Lawande et. al. This simple-yet-powerful technique allows the equilibrium probability density to be accurately evaluated in the presence of multiple potential wells. It is shown that path translation permits the calculation of the unknown ground-state energy of one confining potential by comparison with the known ground-state energy of another. A double finite-square-well potential and a finite-square-well/parabolic-well pair are presented as examples. For real-time calculations, a weighted analytical averaging of the exponential in the classical action is performed over a region of paths. This "windowed action" has both real and imaginary components. The imaginary component yields an exponentially decaying probability for selecting paths, thereby providing a basis for the Monte Carlo evaluation of the real-time integral-over-paths. Examples of a wave-packet in a parabolic well and a wave-packet impinging upon a potential barrier are considered.
Qian, Liwei; Zheng, Haoran; Zhou, Hong; Qin, Ruibin; Li, Jinlong
2013-01-01
The increasing availability of time series expression datasets, although promising, raises a number of new computational challenges. Accordingly, the development of suitable classification methods to make reliable and sound predictions is becoming a pressing issue. We propose, here, a new method to classify time series gene expression via integration of biological networks. We evaluated our approach on 2 different datasets and showed that the use of a hidden Markov model/Gaussian mixture models hybrid explores the time-dependence of the expression data, thereby leading to better prediction results. We demonstrated that the biclustering procedure identifies function-related genes as a whole, giving rise to high accordance in prognosis prediction across independent time series datasets. In addition, we showed that integration of biological networks into our method significantly improves prediction performance. Moreover, we compared our approach with several state-of–the-art algorithms and found that our method outperformed previous approaches with regard to various criteria. Finally, our approach achieved better prediction results on early-stage data, implying the potential of our method for practical prediction. PMID:23516469
Qian, Liwei; Zheng, Haoran; Zhou, Hong; Qin, Ruibin; Li, Jinlong
2013-01-01
The increasing availability of time series expression datasets, although promising, raises a number of new computational challenges. Accordingly, the development of suitable classification methods to make reliable and sound predictions is becoming a pressing issue. We propose, here, a new method to classify time series gene expression via integration of biological networks. We evaluated our approach on 2 different datasets and showed that the use of a hidden Markov model/Gaussian mixture models hybrid explores the time-dependence of the expression data, thereby leading to better prediction results. We demonstrated that the biclustering procedure identifies function-related genes as a whole, giving rise to high accordance in prognosis prediction across independent time series datasets. In addition, we showed that integration of biological networks into our method significantly improves prediction performance. Moreover, we compared our approach with several state-of-the-art algorithms and found that our method outperformed previous approaches with regard to various criteria. Finally, our approach achieved better prediction results on early-stage data, implying the potential of our method for practical prediction. PMID:23516469
NASA Technical Reports Server (NTRS)
Jothiprasad, Giridhar; Mavriplis, Dimitri J.; Caughey, David A.
2002-01-01
The rapid increase in available computational power over the last decade has enabled higher resolution flow simulations and more widespread use of unstructured grid methods for complex geometries. While much of this effort has been focused on steady-state calculations in the aerodynamics community, the need to accurately predict off-design conditions, which may involve substantial amounts of flow separation, points to the need to efficiently simulate unsteady flow fields. Accurate unsteady flow simulations can easily require several orders of magnitude more computational effort than a corresponding steady-state simulation. For this reason, techniques for improving the efficiency of unsteady flow simulations are required in order to make such calculations feasible in the foreseeable future. The purpose of this work is to investigate possible reductions in computer time due to the choice of an efficient time-integration scheme from a series of schemes differing in the order of time-accuracy, and by the use of more efficient techniques to solve the nonlinear equations which arise while using implicit time-integration schemes. This investigation is carried out in the context of a two-dimensional unstructured mesh laminar Navier-Stokes solver.
Integrating Satellite, Radar and Surface Observation with Time and Space Matching
NASA Astrophysics Data System (ADS)
Ho, Y.; Weber, J.
2015-12-01
The Integrated Data Viewer (IDV) from Unidata is a Java™-based software framework for analyzing and visualizing geoscience data. It brings together the ability to display and work with satellite imagery, gridded data, surface observations, balloon soundings, NWS WSR-88D Level II and Level III RADAR data, and NOAA National Profiler Network data, all within a unified interface. Applying time and space matching on the satellite, radar and surface observation datasets will automatically synchronize the display from different data sources and spatially subset to match the display area in the view window. These features allow the IDV users to effectively integrate these observations and provide 3 dimensional views of the weather system to better understand the underlying dynamics and physics of weather phenomena.
New readout integrated circuit using continuous time fixed pattern noise correction
NASA Astrophysics Data System (ADS)
Dupont, Bertrand; Chammings, G.; Rapellin, G.; Mandier, C.; Tchagaspanian, M.; Dupont, Benoit; Peizerat, A.; Yon, J. J.
2008-04-01
LETI has been involved in IRFPA development since 1978; the design department (LETI/DCIS) has focused its work on new ROIC architecture since many years. The trend is to integrate advanced functions into the CMOS design to achieve cost efficient sensors production. Thermal imaging market is today more and more demanding of systems with instant ON capability and low power consumption. The purpose of this paper is to present the latest developments of fixed pattern noise continuous time correction. Several architectures are proposed, some are based on hardwired digital processing and some are purely analog. Both are using scene based algorithms. Moreover a new method is proposed for simultaneous correction of pixel offsets and sensitivities. In this scope, a new architecture of readout integrated circuit has been implemented; this architecture is developed with 0.18μm CMOS technology. The specification and the application of the ROIC are discussed in details.
Saturations-based nonlinear controllers with integral term: validation in real-time
NASA Astrophysics Data System (ADS)
Alatorre, A. G.; Castillo, P.; Mondié, S.
2016-05-01
Popular saturations-based nonlinear controller usually include proportional and derivative components of the state or output. The fact that in many applications, these components do not suffice to insure the convergence to the desired output values, motivate the addition of an integral term. In this paper, three configurations of nonlinear controllers based on saturation functions are improved with an integral component. The stability of the three algorithms is analysed using the Lyapunov theory. Simulation results validate the proposed control laws when they are applied to nonlinear systems with constant and unknown perturbations. Real-time experiments realised with a quad-rotor aerial vehicle and a hovercraft vehicle show that the proposed scheme can follow autonomously some trajectories, and that it could be robust with respect to delays.
Time-Dependent and Time-Integrated Angular Analysis of B -> phi Ks pi0 and B -> phi K+ pi-
Aubert, B; Bona, M; Karyotakis, Y; Lees, J P; Poireau, V
2008-08-04
We perform a time-dependent and time-integrated angular analysis of the B{sup 0} {yields} {psi}K*(892){sup 0}, {psi}K*{sub 2}(1430{sup 0}), and {psi}(K{pi}){sub S-wave}{sup 0} decays with the final sample of about 465 million B{bar B} pairs recorded with the BABAR detector. Overall, twelve parameters are measured for the vector-vector decay, nine parameters for the vector-tensor decay, and three parameters for the vector-scalar decay, including the branching fractions, CP-violation parameters, and parameters sensitive to final state interaction. We use the dependence on the K{pi} invariant mass of the interference between the scalar and vector or tensor components to resolve discrete ambiguities of the strong and weak phases. We use the time-evolution of the B {yields} {psi}K{sub S}{sup 0}{pi}{sup 0} channel to extract the CP-violation phase difference {Delta}{phi}{sub 00} = 0.28 {+-} 0.42 {+-} 0.04 between the B and {bar B} decay amplitudes. When the B {yields} {psi}K{sup {+-}}{pi}{sup {-+}} channel is included, the fractions of longitudinal polarization f{sub L} of the vector-vector and vector-tensor decay modes are measured to be 0.494 {+-} 0.034 {+-} 0.013 and 0.901{sub -0.058}{sup +0.046} {+-} 0.037, respectively. This polarization pattern requires the presence of a helicity-plus amplitude in the vector-vector decay from a presently unknown source.
ERIC Educational Resources Information Center
Mucientes, A. E.; de la Pena, M. A.
2009-01-01
The concentration-time integrals method has been used to solve kinetic equations of parallel-consecutive first-order reactions with a reversible step. This method involves the determination of the area under the curve for the concentration of a given species against time. Computer techniques are used to integrate experimental curves and the method…
Timely integration of safeguards and security with projects at Los Alamos National Laboratory
Price, R.; Blount, P. M.; Garcia, S. W.; Gonzales, R. L.; Salazar, J. B.; Campbell, C. H.
2004-01-01
The Safeguards and Security (S&S) Requirements Integration Team at Los Alamos National Laboratory (LANL) has developed and implemented an innovative management process that will be described in detail. This process systematically integrates S&S planning into construction, facility modifications or upgrades, mission changes, and operational projects. It extends and expands the opportunities provided by the DOE project management manual, DOE M 413.3-1. Through a series of LANL documents, a process is defined and implemented that formally identifies an S&S professional to oversee, coordinate, facilitate, and communicate among the identified S&S organizations and the project organizations over the life cycle of the project. The derived benefits, namely (1) elimination/reduction of re-work or costly retrofitting, (2) overall project cost savings because of timely and improved planning, (3) formal documentation, and (4) support of Integrated Safeguards and Security Management at LANL, will be discussed. How many times, during the construction of a new facility or the modification of an existing facility, have the persons responsible for the project waited until the last possible minute or until after construction is completed to approach the security organizations for their help in safeguarding and securing the facility? It's almost like, 'Oh, by the way, do we need access control and a fence around this building and just what are we going to do with our classified anyway?' Not only is it usually difficult; it's also typically expensive to retrofit or plan for safeguards and security after the fact. Safeguards and security organizations are often blamed for budget overruns and delays in facility occupancy and program startup, but these problems are usually due to poor front-end planning. In an effort to help projects engage safeguards and security in the pre-conceptual or conceptual stages, we implemented a high level formality of operations. We established institutional
Black-and-white hole as a space-time with integrable singularity
NASA Astrophysics Data System (ADS)
Strokov, Vladimir N.; Lukash, Vladimir N.; Mikheeva, Elena V.
2016-01-01
We discuss the problem of singularities in general relativity and emphasize the distinction that should be made between what is understood to be mathematical and physical singularities. We revise examples of space-times that conventionally contain a singularity which, in a sense, does not manifest itself physically. A special attention is paid to the case of integrable singularities for which we propose a well-defined mathematical procedure used to extend the space-time beyond the singularity. We argue that this type of singularity may connect the interior of a black hole with a newly born universe (a space-time referred to as black-and-white hole) giving a resolution to the problem of initial high density and symmetry of the universe. We exemplify by presenting toy models of eternal and astrophysical black-and-white holes.
Integrated survival analysis using an event-time approach in a Bayesian framework.
Walsh, Daniel P; Dreitz, Victoria J; Heisey, Dennis M
2015-02-01
Event-time or continuous-time statistical approaches have been applied throughout the biostatistical literature and have led to numerous scientific advances. However, these techniques have traditionally relied on knowing failure times. This has limited application of these analyses, particularly, within the ecological field where fates of marked animals may be unknown. To address these limitations, we developed an integrated approach within a Bayesian framework to estimate hazard rates in the face of unknown fates. We combine failure/survival times from individuals whose fates are known and times of which are interval-censored with information from those whose fates are unknown, and model the process of detecting animals with unknown fates. This provides the foundation for our integrated model and permits necessary parameter estimation. We provide the Bayesian model, its derivation, and use simulation techniques to investigate the properties and performance of our approach under several scenarios. Lastly, we apply our estimation technique using a piece-wise constant hazard function to investigate the effects of year, age, chick size and sex, sex of the tending adult, and nesting habitat on mortality hazard rates of the endangered mountain plover (Charadrius montanus) chicks. Traditional models were inappropriate for this analysis because fates of some individual chicks were unknown due to failed radio transmitters. Simulations revealed biases of posterior mean estimates were minimal (≤ 4.95%), and posterior distributions behaved as expected with RMSE of the estimates decreasing as sample sizes, detection probability, and survival increased. We determined mortality hazard rates for plover chicks were highest at <5 days old and were lower for chicks with larger birth weights and/or whose nest was within agricultural habitats. Based on its performance, our approach greatly expands the range of problems for which event-time analyses can be used by eliminating the
Steenken, Rike; Weber, Lars; Colonius, Hans; Diederich, Adele
2014-01-01
Modern driver assistance systems make increasing use of auditory and tactile signals in order to reduce the driver's visual information load. This entails potential crossmodal interaction effects that need to be taken into account in designing an optimal system. Here we show that saccadic reaction times to visual targets (cockpit or outside mirror), presented in a driving simulator environment and accompanied by auditory or tactile accessories, follow some well-known spatiotemporal rules of multisensory integration, usually found under confined laboratory conditions. Auditory nontargets speed up reaction time by about 80 ms. The effect tends to be maximal when the nontarget is presented 50 ms before the target and when target and nontarget are spatially coincident. The effect of a tactile nontarget (vibrating steering wheel) was less pronounced and not spatially specific. It is shown that the average reaction times are well-described by the stochastic “time window of integration” model for multisensory integration developed by the authors. This two-stage model postulates that crossmodal interaction occurs only if the peripheral processes from the different sensory modalities terminate within a fixed temporal interval, and that the amount of crossmodal interaction manifests itself in an increase or decrease of second stage processing time. A qualitative test is consistent with the model prediction that the probability of interaction, but not the amount of crossmodal interaction, depends on target–nontarget onset asynchrony. A quantitative model fit yields estimates of individual participants' parameters, including the size of the time window. Some consequences for the design of driver assistance systems are discussed. PMID:24800823
Integrated survival analysis using an event-time approach in a Bayesian framework
Walsh, Daniel P; Dreitz, Victoria J; Heisey, Dennis M
2015-01-01
Event-time or continuous-time statistical approaches have been applied throughout the biostatistical literature and have led to numerous scientific advances. However, these techniques have traditionally relied on knowing failure times. This has limited application of these analyses, particularly, within the ecological field where fates of marked animals may be unknown. To address these limitations, we developed an integrated approach within a Bayesian framework to estimate hazard rates in the face of unknown fates. We combine failure/survival times from individuals whose fates are known and times of which are interval-censored with information from those whose fates are unknown, and model the process of detecting animals with unknown fates. This provides the foundation for our integrated model and permits necessary parameter estimation. We provide the Bayesian model, its derivation, and use simulation techniques to investigate the properties and performance of our approach under several scenarios. Lastly, we apply our estimation technique using a piece-wise constant hazard function to investigate the effects of year, age, chick size and sex, sex of the tending adult, and nesting habitat on mortality hazard rates of the endangered mountain plover (Charadrius montanus) chicks. Traditional models were inappropriate for this analysis because fates of some individual chicks were unknown due to failed radio transmitters. Simulations revealed biases of posterior mean estimates were minimal (≤ 4.95%), and posterior distributions behaved as expected with RMSE of the estimates decreasing as sample sizes, detection probability, and survival increased. We determined mortality hazard rates for plover chicks were highest at <5 days old and were lower for chicks with larger birth weights and/or whose nest was within agricultural habitats. Based on its performance, our approach greatly expands the range of problems for which event-time analyses can be used by eliminating the
Time to Integrate to Nest Test Evaluation in a Mouse DSS-Colitis Model
Häger, Christine; Keubler, Lydia M.; Biernot, Svenja; Dietrich, Jana; Buchheister, Stephanie; Buettner, Manuela; Bleich, André
2015-01-01
Severity assessment in laboratory animals is an important issue regarding the implementation of the 3R concept into biomedical research and pivotal in current EU regulations. In mouse models of inflammatory bowel disease severity assessment is usually undertaken by clinical scoring, especially by monitoring reduction of body weight. This requires daily observance and handling of each mouse, which is time consuming, stressful for the animal and necessitates an experienced observer. The time to integrate to nest test (TINT) is an easily applicable test detecting disturbed welfare by measuring the time interval mice need to integrate nesting material to an existing nest. Here, TINT was utilized to assess severity in a mouse DSS-colitis model. TINT results depended on the group size of mice maintained per cage with most consistent time intervals measured when co-housing 4 to 5 mice. Colitis was induced with 1% or 1.5% DSS in group-housed WT and Cd14-deficient mice. Higher clinical scores and loss of body weight were detected in 1.5% compared to 1% DSS treated mice. TINT time intervals showed no dose dependent differences. However, increased clinical scores, body weight reductions, and increased TINT time intervals were detected in Cd14-/- compared to WT mice revealing mouse strain related differences. Therefore, TINT is an easily applicable method for severity assessment in a mouse colitis model detecting CD14 related differences, but not dose dependent differences. As TINT revealed most consistent results in group-housed mice, we recommend utilization as an additional method substituting clinical monitoring of the individual mouse. PMID:26637175
NASA Astrophysics Data System (ADS)
Falkensammer, Peter; Soegner, Peter I.; zur Nedden, Dieter
2002-05-01
The integration of RIS-PACS systems in radiology units are intended to reduce time consumption in radiology workflow and thus to increase radiologist productivity. Along with the RIS-PACS integration at the University Hospital Innsbruck we analyzed workflow from patient admission to release of final reports before implementation. The follow up study after six months of the implementation is currently in work. In this study we compared chest to skeletal x-ray examinations in 969 patients before the implementation. Drawing the admission-to-release-of-final-report period showed a two-peak diagram with the first peak corresponding to a release of final results on the same day and the second peak to a release on the following day. In the chest x-ray group, 57% were released the same day (mean value 4:02 hours) and 43% the next day (mean value 21:47 hours). Looking at the skeletal x-rays 40% were released the same day (mean value 3:58 hours) and 60% were released the next day (mean value 21:05 hours). Summarizing the results we should say, that the average chest x-ray requires less time than an skeletal x-ray, due to the fact that a greater percentage of reports is released the same day. The most important result is, that the most time consuming workstep is the exchange of data media between radiologist and secretary with at least 5 hours.
A real-time, interactive steering environment for integrated ground water modeling.
Li, Shu-Guang; Liu, Qun
2006-01-01
We present in this note an innovative software environment, called Interactive Ground Water (IGW), for unified deterministic and stochastic ground water modeling. Based on efficient computational algorithms, IGW allows simulating three-dimensional (3D) unsteady flow and transport in saturated media subject to systematic and "random" stresses and geological and chemical heterogeneity. Adopting a new computing paradigm, IGW eliminates the fragmentation in the traditional modeling schemes and allows fully utilizing today's dramatically increased computing power. For many problems, IGW enables real-time modeling, visualization, mapping, and analysis. The software environment functions as a "numerical laboratory" in which an investigator may freely explore the following: creating visually an aquifer system of desired configurations, interactively applying stresses and boundary conditions, and then investigating and visualizing on the fly the geology and flow and transport dynamics. At any time, a researcher can pause to interact dynamically with virtually any aspects of the modeling process and then resume the integrated visual exploration; he or she can initiate, pause, or resume particle tracking, plume modeling, subscale modeling, stochastic modeling, monitoring, and budget analyses. IGW continually provides results that are dynamically processed, overlaid, and displayed. It dynamically merges modeling inputs and outputs into composite two-dimensional/3D images-integrating related data to provide a more complete view of the complex interplay among the geology, hydrology, flow system, and transport. These unique capabilities of real-time modeling, steering, analysis, and mapping expand the utility of models as tools for research, education, and professional investigations. PMID:16961499
Multiparameter radar study of rainfall: Potential application to area-time integral studies
NASA Technical Reports Server (NTRS)
Raghavan, R.; Chandrasekar, V.
1994-01-01
Multiparameter radars measure one or more additional parameters in addition to the coventional reflectivity factor. The combination of radar observations from a multiparameter radar is used to study the time evolution of rainstorms. A technique is presented to self-consistently compare the area-time integral (ATI) and rainfall volume estimates from convective storms, using two different measurements from a multiparameter radar. Rainfall volumes for the lifetime of individual storms are computed using the reflectivity at S band (10-cm wavelength) as well as one-way specific attenuation at X band (3-cm wavelength). Area-time integrals are computed by summing all areas in each radar snapshot having reflectivities (S band) in excess of a preselected threshold. The multiparameter radar data used in this study were acquired by the National Center for Atmospheric Research (NCAR) CP-2 radar during the Cooperative Huntsville Meteorological Experiment (COHMEX) and the Convection and Precipitation/Electrification Experiment (CaPE), respectively. ATI studies were accomplished in this work using multiparameter radar data acquired during the lifetime of six convective events that occurred in the COHMEX radar coverage area. A case study from the COMHEX field campaign (20 July 1986) was selected to depict the various stages in the evolution of a storm over which the ATI and rainfall volume computations were performed using multiparameter radar data. Another case study from the CaPE field campaign (12 August 1991) was used to demonstrate the evolution of a convective cell based on differential reflectivity observations.
An integrated, subsurface characterization system for real-time, in-situ field analysis
Baumgart, C.W.; Creager, J.; Mathes, J.; Pounds, T.; VanDeusen, A.; Warthen, B.
1996-02-01
This paper describes current efforts at AlliedSignal Federal Manufacturing and Technologies (FM and T) to develop and field an in-situ, data analysis platform to acquire, process, and display site survey data in near real-time. In past years, FM and T has performed a number of site survey tasks. Each of these surveys was unique in application as well as in the type of data processing and analysis that was required to extract and visualize useful site characterization information. However, common to each of these surveys were the following specific computational and operational requirements: (1) a capability to acquire, process, and visualize the site survey data in the field; (2) a capability to perform all processing in a timely fashion (ideally real-time); and (3) a technique for correlating (or fusing) data streams from multiple sensors. Two more general, but no less important, requirements include system architecture modularity and positioning capability. Potential applications include: survey, evaluation, and remediation of numerous Department of Defense and Department of Energy waste sites; real-time detection and characterization of unexploded ordnance and landmines; survey, evaluation, and remediation of industrial waste sites; location of underground utility lines; and providing law enforcement agencies with real-time surveys of crime scenes. The paper describes an integrated data acquisition, processing, and visualization platform that is capable of performing in-situ data processing, interpretation, and visualization in real-time.
Real-time pickup and display integral imaging system without pseudoscopic problem
NASA Astrophysics Data System (ADS)
Kim, Jonghyun; Jung, Jae-Hyun; Lee, Byoungho
2013-03-01
We propose a novel real-time pickup and display of integral imaging system using only a lens array and a high speed charge coupled device (CCD). A simple lens array and a high speed CCD can capture 3D information of the object and a commercial liquid crystal (LC) display panel shows the elemental image in real-time. Reconstructed image is real and orthographic so that the observer can touch the 3D image. Furthermore, our system is free from pseudoscopic problem by adopting recent pixel mapping algorithm. This algorithm, based on image interweaving process, can also change the depth plane of the displayed 3D images in real-time. C++ programming is used for real-time capturing, image processing, and display. For real-time high quality 3D video generation, a high resolution and high frame rate CCD (AVT Prosilica GX2300C) and LC display panel (IBM 22inch 3840×2400) are used in proposed system. Proper simulation and experiment are presented to verify our proposed system. We expect that our research can be the basic technology for real-time 3D broadcasting and interactive 3D technology.
Implicit Time Integration for Multiscale Molecular Dynamics Using Transcendental Padé Approximants.
Abi Mansour, Andrew; Ortoleva, Peter J
2016-04-12
Molecular dynamics systems evolve through the interplay of collective and localized disturbances. As a practical consequence, there is a restriction on the time step imposed by the broad spectrum of time scales involved. To resolve this restriction, multiscale factorization was introduced for molecular dynamics as a method that exploits the separation of time scales by coevolving the coarse-grained and atom-resolved states via Trotter factorization. Developing a stable time-marching scheme for this coevolution, however, is challenging because the coarse-grained dynamical equations depend on the microstate; therefore, these equations cannot be expressed in closed form. The objective of this paper is to develop an implicit time integration scheme for multiscale simulation of large systems over long periods of time and with high accuracy. The scheme uses Padé approximants to account for both the stochastic and deterministic features of the coarse-grained dynamics. The method is demonstrated for a protein either undergoing a conformational change or migrating under the influence of an external force. The method shows promise in accelerating multiscale molecular dynamics without a loss of atomic precision or the need to conjecture the form of coarse-grained governing equations. PMID:26845510
NASA Astrophysics Data System (ADS)
Wallstedt, P. C.; Guilkey, J. E.
2008-11-01
The stability and accuracy of the generalized interpolation material point (GIMP) Method is measured directly through carefully-formulated manufactured solutions over wide ranges of CFL numbers and mesh sizes. The manufactured solutions are described in detail. The accuracy and stability of several time integration schemes are compared via numerical experiments. The effect of various treatments of particle "size" are also considered. The hypothesis that GIMP is most accurate when particles remain contiguous and non-overlapping is confirmed by comparing manufactured solutions with and without this property.
Data Integration in Support of a Real-Time Biosurveillance Network
NASA Astrophysics Data System (ADS)
Cross, S. L.; Scott, G. I.; Miglarese, J. V.
2008-12-01
Recent emergency and security events from both human and natural causes have increased the urgency for multidisciplinary data integration. For example, understanding natural resource mortalities on any given day and time of year may result in the timely identification of an intentional biological or chemical act, as well as assist in the development of recovery and restoration plans. The South Carolina Environmental Surveillance Network (ESN) is a real-time surveillance network of coastal-zone wildlife mortality incidents (e.g. fish kills, bird kills, animal disease outbreaks, harmful algal blooms, marine mammal strandings, etc.) that (1) notifies participating network science and regulatory experts of incidents; (2) allows for quick assessments of potential links between and among mortalities and (3) provides a mechanism to alert the emergency management community of incidents that could impact commerce and public health. The ESN data management system relies on a resource-based (or RESTful) approach and includes a Web mapping application that provides access to both real-time and historical data, as well as data flow that analyzes event co-occurrence and provides for email notification of a number of state and federal partners. Notably, it is not simply the occurrence, but the co-occurrence of these events that can signal emergency conditions; thus the real value of the ESN is in its integration of data streams across state and federal administrative lines that have historically provided barriers to data and information flow. In our experience, two recurring types of obstacles to data system integration are particularly challenging. One is the cultural tendency for an agency or agent to maintain tight control over data that they have collected. The second is the reluctance of Information Technology (IT) managers to allow remote access to data systems under their control, regardless of security measures taken. The ESN development has thus far been successful due
Interconnect modeling using integrated time-domain and frequency-domain techniques
You, Hong; Yeh, Chune-Sin; Gadepally, B.
1995-12-31
This paper presents an integrated time- and-frequency-domain technique for characterization and modeling of parasitic effects associated with interconnects. This technique enables direct measurements of critical transient as well as frequency responses of interconnects; accurate and efficient SPICE model extraction for coupled lines; and cross-domain verification of the measured data as well as the extracted models. To illustrate its application this technique is applied to characterize and extract the equivalent circuit model of the I/O bus on a real-world printed circuit board.
Dimensional regularization of the path integral in curved space on an infinite time interval
NASA Astrophysics Data System (ADS)
Bastianelli, F.; Corradini, O.; van Nieuwenhuizen, P.
2000-09-01
We use dimensional regularization to evaluate quantum mechanical path integrals in arbitrary curved spaces on an infinite time interval. We perform 3-loop calculations in Riemann normal coordinates, and 2-loop calculations in general coordinates. It is shown that one only needs a covariant two-loop counterterm (VDR=ℏ2/8R) to obtain the same results as obtained earlier in other regularization schemes. It is also shown that the mass term needed in order to avoid infrared divergences explicitly breaks general covariance in the final result.
Time transformations and Cowell's method. [for numerical integration of satellite motion equations
NASA Technical Reports Server (NTRS)
Velez, C. E.; Hilinski, S.
1978-01-01
The precise numerical integration of Cowell's equations of satellite motion is frequently performed with an independent variable s defined by an equation of the form dt = cr to the n-th power ds, where t represents time, r the radial distance from the center of attraction, c is a constant, and n is a parameter. This has been primarily motivated by the 'uniformizing' effects of such a transformation resulting in desirable 'analytic' stepsize control for elliptical orbits. This report discusses the 'proper' choice of the parameter n defining the independent variable s for various types of orbits and perturbation models, and develops a criterion for its selection.
Splitting methods for time integration of trajectories in combined electric and magnetic fields.
Knapp, Christian; Kendl, Alexander; Koskela, Antti; Ostermann, Alexander
2015-12-01
The equations of motion of a single particle subject to an arbitrary electric and a static magnetic field form a Poisson system. We present a second-order time integration method which preserves well the Poisson structure and compare it to commonly used algorithms, such as the Boris scheme. All the methods are represented in a general framework of splitting methods. We use the so-called ϕ functions, which give efficient ways for both analyzing and implementing the algorithms. Numerical experiments show an excellent long term stability for the method considered. PMID:26764856
Jin Jianyue; Drzymala, Robert; Li Zuofeng
2004-12-01
The purpose of this study is to develop a simple independent dose calculation method to verify treatment plans for Leksell Gamma Knife radiosurgery. Our approach uses the total integral dose within the skull as an end point for comparison. The total integral dose is computed using a spreadsheet and is compared to that obtained from Leksell GammaPlan registered . It is calculated as the sum of the integral doses of 201 beams, each passing through a cylindrical volume. The average length of the cylinders is estimated from the Skull-Scaler measurement data taken before treatment. Correction factors are applied to the length of the cylinder depending on the location of a shot in the skull. The radius of the cylinder corresponds to the collimator aperture of the helmet, with a correction factor for the beam penumbra and scattering. We have tested our simple spreadsheet program using treatment plans of 40 patients treated with Gamma Knife registered in our center. These patients differ in geometry, size, lesion locations, collimator helmet, and treatment complexities. Results show that differences between our calculations and treatment planning results are typically within {+-}3%, with a maximum difference of {+-}3.8%. We demonstrate that our spreadsheet program is a convenient and effective independent method to verify treatment planning irradiation times prior to implementation of Gamma Knife radiosurgery.
In a Time of Change: Integrating the Arts and Humanities with Climate Change Science in Alaska
NASA Astrophysics Data System (ADS)
Leigh, M.; Golux, S.; Franzen, K.
2011-12-01
The arts and humanities have a powerful capacity to create lines of communication between the public, policy and scientific spheres. A growing network of visual and performing artists, writers and scientists has been actively working together since 2007 to integrate scientific and artistic perspectives on climate change in interior Alaska. These efforts have involved field workshops and collaborative creative processes culminating in public performances and a visual art exhibit. The most recent multimedia event was entitled In a Time of Change: Envisioning the Future, and challenged artists and scientists to consider future scenarios of climate change. This event included a public performance featuring original theatre, modern dance, Alaska Native Dance, poetry and music that was presented concurrently with an art exhibit featuring original works by 24 Alaskan visual artists. A related effort targeted K12 students, through an early college course entitled Climate Change and Creative Expression, which was offered to high school students at a predominantly Alaska Native charter school and integrated climate change science, creative writing, theatre and dance. Our program at Bonanza Creek Long Term Ecological Research (LTER) site is just one of many successful efforts to integrate arts and humanities with science within and beyond the NSF LTER Program. The efforts of various LTER sites to engage the arts and humanities with science, the public and policymakers have successfully generated excitement, facilitated mutual understanding, and promoted meaningful dialogue on issues facing science and society. The future outlook for integration of arts and humanities with science appears promising, with increasing interest from artists, scientists and scientific funding agencies.
NASA Astrophysics Data System (ADS)
Geissman, J. W.
2013-12-01
We celebrate the 50th anniversary of the publication of the Vine-Matthews/Morley-Larochelle hypothesis (Vine and Matthews, Nature, 1963, v. 199, #4897, p. 947-949), which integrated marine magnetic anomaly data with a rapidly evolving terrestrial-based geomagnetic polarity time scale (GPTS). The five decades of research since 1963 have witnessed the expansion and refinement of the GPTS, to the point where ages of magnetochron boundaries, in particular in the Cenozoic, can be estimated with uncertainties better than 0.1%. This has come about by integrating high precision geochronology, cyclostratigraphy at different time scales, and magnetic polarity data of increased quality, allowing extension of the GPTS back into the Paleozoic. The definition of a high resolution GPTS across time intervals of major events in Earth history has been of particular interest, as a specific magnetochron boundary correlated across several localities represents a singular global datum. A prime example is the end Permian, when some 80 percent of genus-level extinctions and a range of 75 to 96 percent species- level extinctions took place in the marine environment, depending upon clade. Much our understanding of the Permian-Triassic boundary (PTB) is based on relatively slowly deposited marine sequences in Europe and Asia, yet a growing body of observations from continental sequences demonstrates a similar extinction event and new polarity data from some of these sequences are critical to refining the GPTS across the PTB and testing synchronicity of marine and terrestrial events. The data show that the end-Permian ecological crisis and the conodont calibrated biostratigraphic PTB both followed a key polarity reversal between a short interval (subchron) of reverse polarity to a considerably longer (chron) of normal polarity. Central European Basin strata (continental Permian and epicontinental Triassic) yield high-quality magnetic polarity stratigraphic records (Szurlies et al., 2003
2012-01-01
Background Tardigrades are multicellular organisms, resistant to extreme environmental changes such as heat, drought, radiation and freezing. They outlast these conditions in an inactive form (tun) to escape damage to cellular structures and cell death. Tardigrades are apparently able to prevent or repair such damage and are therefore a crucial model organism for stress tolerance. Cultures of the tardigrade Milnesium tardigradum were dehydrated by removing the surrounding water to induce tun formation. During this process and the subsequent rehydration, metabolites were measured in a time series by GC-MS. Additionally expressed sequence tags are available, especially libraries generated from the active and inactive state. The aim of this integrated analysis is to trace changes in tardigrade metabolism and identify pathways responsible for their extreme resistance against physical stress. Results In this study we propose a novel integrative approach for the analysis of metabolic networks to identify modules of joint shifts on the transcriptomic and metabolic levels. We derive a tardigrade-specific metabolic network represented as an undirected graph with 3,658 nodes (metabolites) and 4,378 edges (reactions). Time course metabolite profiles are used to score the network nodes showing a significant change over time. The edges are scored according to information on enzymes from the EST data. Using this combined information, we identify a key subnetwork (functional module) of concerted changes in metabolic pathways, specific for de- and rehydration. The module is enriched in reactions showing significant changes in metabolite levels and enzyme abundance during the transition. It resembles the cessation of a measurable metabolism (e.g. glycolysis and amino acid anabolism) during the tun formation, the production of storage metabolites and bioprotectants, such as DNA stabilizers, and the generation of amino acids and cellular components from monosaccharides as carbon and
Compact time- and space-integrating SAR processor: design and development status
NASA Astrophysics Data System (ADS)
Haney, Michael W.; Levy, James J.; Christensen, Marc P.; Michael, Robert R., Jr.; Mock, Michael M.
1994-06-01
Progress toward a flight demonstration of the acousto-optic time- and space- integrating real-time SAR image formation processor program is reported. The concept overcomes the size and power consumption limitations of electronic approaches by using compact, rugged, and low-power analog optical signal processing techniques for the most computationally taxing portions of the SAR imaging problem. Flexibility and performance are maintained by the use of digital electronics for the critical low-complexity filter generation and output image processing functions. The results reported include tests of a laboratory version of the concept, a description of the compact optical design that will be implemented, and an overview of the electronic interface and controller modules of the flight-test system.
A hybrid method for solving time-domain integral equations in transient scattering
NASA Astrophysics Data System (ADS)
Tijhuis, A. G.; Wiemans, R.; Kuester, E. F.
A new hybrid method is proposed for the numerical solution of integral equations describing transient scattering problems. The basic idea behind the method is to first discretize in space, and then solve the resulting system of linear time-domain equations by carrying out a temporal Laplace transformation. This approach combines the efficiency of the marching-on-in-time method with the stability and the accuracy of frequency-domain techniques. Numerical results are presented for the scattering of E-polarized, pulsed waves by a one-dimensionally inhomogeneous, lossy dielectric slab located in between two homogeneous, lossless dielectric half-spaces, and by a radially inhomogeneous, lossy dielectric circular cylinder embedded in vacuum. For these problems, the hybrid method turns out to be more powerful than existing solution techniques.
Ying, Wenjun; Henriquez, Craig S.
2015-01-01
A both space and time adaptive algorithm is presented for simulating electrical wave propagation in the Purkinje system of the heart. The equations governing the distribution of electric potential over the system are solved in time with the method of lines. At each timestep, by an operator splitting technique, the space-dependent but linear diffusion part and the nonlinear but space-independent reactions part in the partial differential equations are integrated separately with implicit schemes, which have better stability and allow larger timesteps than explicit ones. The linear diffusion equation on each edge of the system is spatially discretized with the continuous piecewise linear finite element method. The adaptive algorithm can automatically recognize when and where the electrical wave starts to leave or enter the computational domain due to external current/voltage stimulation, self-excitation, or local change of membrane properties. Numerical examples demonstrating efficiency and accuracy of the adaptive algorithm are presented. PMID:26581455
Kovaleva, Agnessa; Manevitch, Leonid I; Kosevich, Yuriy A
2011-02-01
We demonstrate that in significant limiting cases the problem of irreversible energy transfer in an oscillatory system with time-dependent parameters can be efficiently solved in terms of the Fresnel integrals. For definiteness, we consider a system of two weakly coupled linear oscillators in which the first oscillator with constant parameters is excited by an initial impulse, whereas the coupled oscillator with a slowly varying frequency is initially at rest but then acts as an energy trap. We show that the evolution equations of the slow passage through resonance are identical to the equations of the Landau-Zener tunneling problem, and therefore, the suggested asymptotic solution of the classical problem provides a simple analytic description of the quantum Landau-Zener tunneling with arbitrary initial conditions over a finite time interval. A correctness of approximations is confirmed by numerical simulations. PMID:21405919
Earl, R.D.; Zeng, G.L.; Zhang, B.
2005-09-15
This article considers a hypothetical imaging device with a spinning slat collimator that measures parallel-planar-integral data from an object. This device rotates around the object 180 deg. and stops at N positions uniformly distributed over this 180 deg. . At each stop, the device spins on its own axis 180 deg. and acquires measurements at M positions uniformly distributed over this 180 deg. . For a fixed total imaging time, an optimal distribution of the scanning time among the data measurement locations is searched by a nonlinear programming method: Nelder-Mead's simplex method. The optimal dwell time is approximately proportional to the weighting factor in the backprojector of the reconstruction algorithm. By using an optimal dwell-time profile, the reconstruction signal-to-noise ratio has a gain of 23%-24% for the filtered backprojection algorithm and a gain of 10%-18% for the iterative algorithms, compared with the situation when a constant dwell-time profile is used.
Simulation of a Real-Time Local Data Integration System over East-Central Florida
NASA Technical Reports Server (NTRS)
Case, Jonathan
1999-01-01
The Applied Meteorology Unit (AMU) simulated a real-time configuration of a Local Data Integration System (LDIS) using data from 15-28 February 1999. The objectives were to assess the utility of a simulated real-time LDIS, evaluate and extrapolate system performance to identify the hardware necessary to run a real-time LDIS, and determine the sensitivities of LDIS. The ultimate goal for running LDIS is to generate analysis products that enhance short-range (less than 6 h) weather forecasts issued in support of the 45th Weather Squadron, Spaceflight Meteorology Group, and Melbourne National Weather Service operational requirements. The simulation used the Advanced Regional Prediction System (ARPS) Data Analysis System (ADAS) software on an IBM RS/6000 workstation with a 67-MHz processor. This configuration ran in real-time, but not sufficiently fast for operational requirements. Thus, the AMU recommends a workstation with a 200-MHz processor and 512 megabytes of memory to run the AMU's configuration of LDIS in real-time. This report presents results from two case studies and several data sensitivity experiments. ADAS demonstrates utility through its ability to depict high-resolution cloud and wind features in a variety of weather situations. The sensitivity experiments illustrate the influence of disparate data on the resulting ADAS analyses.
Integrators of several orders in time to study the evolution of an aerosol by coagulation
NASA Astrophysics Data System (ADS)
Fernández-Díaz, J. M.; Rodríguez Braña, M. A.; Argüelles Díaz, K.; Gómez García, G.; García Nieto, P. J.
We have obtained some numerical methods to integrate the coagulation equation for an aerosol. They are semi-implicit and stable regarding the time integration step, which can be freely chosen (a very important matter in numerical solution of differential equations). The methods are of two types: extrapolative (based on a previously known first-order semi-implicit formula) and purely semi-implicit, both mass-conservative. The same methodology used here to develop these new methods can be applied to improve the well-known sectional ones. The extrapolative and the semi-implicit methods are really of the order we had deduced from their analysis. However, as the order of the method increases, for small time steps, the roundoff causes the error no longer to behave as expected. The extrapolative methods are self-starting but the semi-implicit ones are not, so we need the first ones to start the others. If we take into account both the error and the CPU time, the second-order methods are comparable, but the third-order semi-implicit one is better than the extrapolative one. The comparison of higher order methods is disturbed by the roundoff error. Both methods can be used with fixed and moving bins with respect to the discretization of the size in the particle size distribution. These methods are valid to complement the specific ones developed to solve the growth and other phenomena in the time-splitting method which is used to analyse the evolution of an aerosol in the general case.
Integrating roots into a whole plant network of flowering time genes in Arabidopsis thaliana.
Bouché, Frédéric; D'Aloia, Maria; Tocquin, Pierre; Lobet, Guillaume; Detry, Nathalie; Périlleux, Claire
2016-01-01
Molecular data concerning the involvement of roots in the genetic pathways regulating floral transition are lacking. In this study, we performed global analyses of the root transcriptome in Arabidopsis in order to identify flowering time genes that are expressed in the roots and genes that are differentially expressed in the roots during the induction of flowering. Data mining of public microarray experiments uncovered that about 200 genes whose mutations are reported to alter flowering time are expressed in the roots (i.e. were detected in more than 50% of the microarrays). However, only a few flowering integrator genes passed the analysis cutoff. Comparison of root transcriptome in short days and during synchronized induction of flowering by a single 22-h long day revealed that 595 genes were differentially expressed. Enrichment analyses of differentially expressed genes in root tissues, gene ontology categories, and cis-regulatory elements converged towards sugar signaling. We concluded that roots are integrated in systemic signaling, whereby carbon supply coordinates growth at the whole plant level during the induction of flowering. This coordination could involve the root circadian clock and cytokinin biosynthesis as a feed forward loop towards the shoot. PMID:27352932
Reithmaier, G.; Lichtmannecker, S.; Reichert, T.; Hasch, P.; Müller, K.; Bichler, M.; Gross, R.; Finley, J. J.
2013-01-01
We report the routing of quantum light emitted by self-assembled InGaAs quantum dots (QDs) into the optical modes of a GaAs ridge waveguide and its efficient detection on-chip via evanescent coupling to NbN superconducting nanowire single photon detectors (SSPDs). The waveguide coupled SSPDs primarily detect QD luminescence, with scattered photons from the excitation laser onto the proximal detector being negligible by comparison. The SSPD detection efficiency from the evanescently coupled waveguide modes is shown to be two orders of magnitude larger when compared with operation under normal incidence illumination, due to the much longer optical interaction length. Furthermore, in-situ time resolved measurements performed using the integrated detector show an average QD spontaneous emission lifetime of 0.95 ns, measured with a timing jitter of only 72 ps. The performance metrics of the SSPD integrated directly onto GaAs nano-photonic hardware confirms the strong potential for on-chip few-photon quantum optics using such semiconductor-superconductor hybrid systems. PMID:23712624
Integrating roots into a whole plant network of flowering time genes in Arabidopsis thaliana
Bouché, Frédéric; D’Aloia, Maria; Tocquin, Pierre; Lobet, Guillaume; Detry, Nathalie; Périlleux, Claire
2016-01-01
Molecular data concerning the involvement of roots in the genetic pathways regulating floral transition are lacking. In this study, we performed global analyses of the root transcriptome in Arabidopsis in order to identify flowering time genes that are expressed in the roots and genes that are differentially expressed in the roots during the induction of flowering. Data mining of public microarray experiments uncovered that about 200 genes whose mutations are reported to alter flowering time are expressed in the roots (i.e. were detected in more than 50% of the microarrays). However, only a few flowering integrator genes passed the analysis cutoff. Comparison of root transcriptome in short days and during synchronized induction of flowering by a single 22-h long day revealed that 595 genes were differentially expressed. Enrichment analyses of differentially expressed genes in root tissues, gene ontology categories, and cis-regulatory elements converged towards sugar signaling. We concluded that roots are integrated in systemic signaling, whereby carbon supply coordinates growth at the whole plant level during the induction of flowering. This coordination could involve the root circadian clock and cytokinin biosynthesis as a feed forward loop towards the shoot. PMID:27352932
A time-domain finite element boundary integration method for ultrasonic nondestructive evaluation.
Shi, Fan; Choi, Wonjae; Skelton, Elizabeth A; Lowe, Michael J S; Craster, Richard V
2014-12-01
A 2-D and 3-D numerical modeling approach for calculating the elastic wave scattering signals from complex stress-free defects is evaluated. In this method, efficient boundary integration across the complex boundary of the defect is coupled with a time-domain finite element (FE) solver. The model is designed to simulate time-domain ultrasonic nondestructive evaluation in bulk media. This approach makes use of the hybrid concept of linking a local numerical model to compute the near-field scattering behavior and theoretical mathematical formulas for postprocessing to calculate the received signals. It minimizes the number of monitoring signals from the FE calculation so that the computation effort in postprocessing decreases significantly. In addition, by neglecting the conventional regular monitoring box, the region for FE calculation can be made smaller. In this paper, the boundary integral method is implemented in a commercial FE code, and it is validated by comparing the scattering signals with results from corresponding full FE models. The coupled method is then implemented in real inspection scenarios in both 2-D and 3-D, and the accuracy and the efficiency are demonstrated. The limitations of the proposed model and future works are also discussed. PMID:25474780
Database Integration: An Intial Step Towards the Deep-Time Data Infrastructure
NASA Astrophysics Data System (ADS)
Kolankowski, S. M.; Fox, P. A.; Ma, X.
2015-12-01
As our knowledge of Earth's geologic history grows, we require more robust methods of sharing immense amounts of data. Various databases across numerous disciplines have been widely utilized to offer extensive information on very specific pieces of both Earth's history and its current state, ie. fossil record, rock composition, proteins, etc. In order to gain a deeper understanding of our planet's past we must combine the resources present in our online communities. These databases could be a powerful force in identifying previously unseen correlations if used in tandem rather than as separate entities. Creating a unifying site that provides links to these databases will aid in our ability as a collaborative scientific community to utilize our findings on a larger scale. The Deep-Time Data Infrastructure is currently underway as part of a larger effort to accomplish this goal. DTDI works not to build a new database, but to integrate existing resources. This research is the beginning step in the DTDI program. To create this infrastructure, all current geologic and related databases had to be identified and their schema recorded. Using variables from their combined records, we are able to determine the best way to integrate them using common factors. The Deep-Time Data Infrastructure will allow geoscientists to bridge gaps in data and further our understanding of our planet's history.
Colonius, Hans; Diederich, Adele
2012-01-01
In the crossmodal signals paradigm (CSP) participants are instructed to respond to a set of stimuli from different modalities, presented more or less simultaneously, as soon as a stimulus from any modality has been detected. In the focused attention paradigm (FAP), on the other hand, responses should only be made to a stimulus from a pre-defined target modality and stimuli from non-target modalities should be ignored. Whichever paradigm is being applied, a typical result is that responses tend to be faster to crossmodal stimuli than to unimodal stimuli, a phenomenon often referred to as "crossmodal interaction." Here, we investigate predictions of the time-window-of-integration (TWIN) modeling framework previously proposed by the authors. It is shown that TWIN makes specific qualitative and quantitative predictions on how the two paradigms differ with respect to the probability of multisensory integration and the amount of response enhancement, including the effect of stimulus intensity ("inverse effectiveness"). Introducing a decision-theoretic framework for TWIN further allows comparing the two paradigms with respect to the predicted optimal time window size and its dependence on the prior probability that the crossmodal stimulus information refers to the same event. In order to test these predictions, experimental studies that systematically compare crossmodal effects under stimulus conditions that are identical except for the CSP-FAP instruction should be performed in the future. PMID:22952460
Reithmaier, G; Lichtmannecker, S; Reichert, T; Hasch, P; Müller, K; Bichler, M; Gross, R; Finley, J J
2013-01-01
We report the routing of quantum light emitted by self-assembled InGaAs quantum dots (QDs) into the optical modes of a GaAs ridge waveguide and its efficient detection on-chip via evanescent coupling to NbN superconducting nanowire single photon detectors (SSPDs). The waveguide coupled SSPDs primarily detect QD luminescence, with scattered photons from the excitation laser onto the proximal detector being negligible by comparison. The SSPD detection efficiency from the evanescently coupled waveguide modes is shown to be two orders of magnitude larger when compared with operation under normal incidence illumination, due to the much longer optical interaction length. Furthermore, in-situ time resolved measurements performed using the integrated detector show an average QD spontaneous emission lifetime of 0.95 ns, measured with a timing jitter of only 72 ps. The performance metrics of the SSPD integrated directly onto GaAs nano-photonic hardware confirms the strong potential for on-chip few-photon quantum optics using such semiconductor-superconductor hybrid systems. PMID:23712624
Gonçalves, Joana P; Aires, Ricardo S; Francisco, Alexandre P; Madeira, Sara C
2012-01-01
Explaining regulatory mechanisms is crucial to understand complex cellular responses leading to system perturbations. Some strategies reverse engineer regulatory interactions from experimental data, while others identify functional regulatory units (modules) under the assumption that biological systems yield a modular organization. Most modular studies focus on network structure and static properties, ignoring that gene regulation is largely driven by stimulus-response behavior. Expression time series are key to gain insight into dynamics, but have been insufficiently explored by current methods, which often (1) apply generic algorithms unsuited for expression analysis over time, due to inability to maintain the chronology of events or incorporate time dependency; (2) ignore local patterns, abundant in most interesting cases of transcriptional activity; (3) neglect physical binding or lack automatic association of regulators, focusing mainly on expression patterns; or (4) limit the discovery to a predefined number of modules. We propose Regulatory Snapshots, an integrative mining approach to identify regulatory modules over time by combining transcriptional control with response, while overcoming the above challenges. Temporal biclustering is first used to reveal transcriptional modules composed of genes showing coherent expression profiles over time. Personalized ranking is then applied to prioritize prominent regulators targeting the modules at each time point using a network of documented regulatory associations and the expression data. Custom graphics are finally depicted to expose the regulatory activity in a module at consecutive time points (snapshots). Regulatory Snapshots successfully unraveled modules underlying yeast response to heat shock and human epithelial-to-mesenchymal transition, based on regulations documented in the YEASTRACT and JASPAR databases, respectively, and available expression data. Regulatory players involved in functionally enriched
NASA Astrophysics Data System (ADS)
He, M.; Hardin, D. M.; Goodman, M.; Blakeslee, R.
2008-05-01
The Real Time Mission Monitor (RTMM) is an interactive visualization application based on Google Earth, that provides situational awareness and field asset management during NASA field campaigns. The RTMM can integrate data and imagery from numerous sources including GOES-12, GOES-10, and TRMM satellites. Simultaneously, it can display data and imagery from surface observations including Nexrad, NPOL and SMART- R radars. In addition to all these it can display output from models and real-time flight tracks of all aircraft involved in the experiment. In some instances the RTMM can also display measurements from scientific instruments as they are being flown. All data are recorded and archived in an on-line system enabling playback and review of all sorties. This is invaluable in preparing for future deployments and in exercising case studies. The RTMM facilitates pre-flight planning, in-flight monitoring, development of adaptive flight strategies and post- flight data analyses and assessments. Since the RTMM is available via the internet - during the actual experiment - project managers, scientists and mission planners can collaborate no matter where they are located as long as they have a viable internet connection. In addition, the system is open so that the general public can also view the experiment, in-progress, with Google Earth. Predecessors of RTMM were originally deployed in 2002 as part of the Altus Cumulus Electrification Study (ACES) to monitor uninhabited aerial vehicles near thunderstorms. In 2005 an interactive Java-based web prototype supported the airborne Lightning Instrument Package (LIP) during the Tropical Cloud Systems and Processes (TCSP) experiment. In 2006 the technology was adapted to the 3D Google Earth virtual globe and in 2007 its capabilities were extended to support multiple NASA aircraft (ER-2, WB-57, DC-8) during Tropical Composition, Clouds and Climate Coupling (TC4) experiment and 2007 Summer Aerosonde field study. In April 2008
Integrated micro-optofluidic platform for real-time detection of airborne microorganisms.
Choi, Jeongan; Kang, Miran; Jung, Jae Hee
2015-01-01
We demonstrate an integrated micro-optofluidic platform for real-time, continuous detection and quantification of airborne microorganisms. Measurements of the fluorescence and light scattering from single particles in a microfluidic channel are used to determine the total particle number concentration and the microorganism number concentration in real-time. The system performance is examined by evaluating standard particle measurements with various sample flow rates and the ratios of fluorescent to non-fluorescent particles. To apply this method to real-time detection of airborne microorganisms, airborne Escherichia coli, Bacillus subtilis, and Staphylococcus epidermidis cells were introduced into the micro-optofluidic platform via bioaerosol generation, and a liquid-type particle collection setup was used. We demonstrate successful discrimination of SYTO82-dyed fluorescent bacterial cells from other residue particles in a continuous and real-time manner. In comparison with traditional microscopy cell counting and colony culture methods, this micro-optofluidic platform is not only more accurate in terms of the detection efficiency for airborne microorganisms but it also provides additional information on the total particle number concentration. PMID:26522006
Clutter interference and the integration time of echoes in the echolocating bat, Eptesicus fuscus.
Simmons, J A; Freedman, E G; Stevenson, S B; Chen, L; Wohlgenant, T J
1989-10-01
The ability of the echolocating bat, Eptesicus fuscus, to detect a sonar target is affected by the presence of other targets along the same axis at slightly different ranges. If echoes from one target arrive at about the same delay as echoes from another target, clutter interference occurs and one set of echoes masks the other. Although the bat's sonar emissions and the echoes themselves are 2 to 5 ms long, echoes (of approximately equal sensation levels--around 15 dB SL) only interfere with each other if they arrive within 200 to 400 microseconds of the same arrival time. This figure is an estimate of the integration time of the bat's sonar receiver for echoes. The fine structure of the clutter-interference data reflects the reinforcement and cancellation of echoes according to their time separation. When clutter interference first occurs, the waveforms of test and cluttering echoes already overlap for much of their duration. The masking effect underlying clutter interference appears specifically due to overlap, not between raw echo waveforms, but between the patterns of mechanical excitation created when echoes pass through bandpass filters equivalent to auditory-nerve tuning curves. While the time scale of clutter interference is substantially shorter than the duration of echo waveforms, it still is much longer than the eventual width of a target's range-axis image expressed in terms of echo delay. PMID:2808907
Integrated micro-optofluidic platform for real-time detection of airborne microorganisms
Choi, Jeongan; Kang, Miran; Jung, Jae Hee
2015-01-01
We demonstrate an integrated micro-optofluidic platform for real-time, continuous detection and quantification of airborne microorganisms. Measurements of the fluorescence and light scattering from single particles in a microfluidic channel are used to determine the total particle number concentration and the microorganism number concentration in real-time. The system performance is examined by evaluating standard particle measurements with various sample flow rates and the ratios of fluorescent to non-fluorescent particles. To apply this method to real-time detection of airborne microorganisms, airborne Escherichia coli, Bacillus subtilis, and Staphylococcus epidermidis cells were introduced into the micro-optofluidic platform via bioaerosol generation, and a liquid-type particle collection setup was used. We demonstrate successful discrimination of SYTO82-dyed fluorescent bacterial cells from other residue particles in a continuous and real-time manner. In comparison with traditional microscopy cell counting and colony culture methods, this micro-optofluidic platform is not only more accurate in terms of the detection efficiency for airborne microorganisms but it also provides additional information on the total particle number concentration. PMID:26522006
Integrated micro-optofluidic platform for real-time detection of airborne microorganisms
NASA Astrophysics Data System (ADS)
Choi, Jeongan; Kang, Miran; Jung, Jae Hee
2015-11-01
We demonstrate an integrated micro-optofluidic platform for real-time, continuous detection and quantification of airborne microorganisms. Measurements of the fluorescence and light scattering from single particles in a microfluidic channel are used to determine the total particle number concentration and the microorganism number concentration in real-time. The system performance is examined by evaluating standard particle measurements with various sample flow rates and the ratios of fluorescent to non-fluorescent particles. To apply this method to real-time detection of airborne microorganisms, airborne Escherichia coli, Bacillus subtilis, and Staphylococcus epidermidis cells were introduced into the micro-optofluidic platform via bioaerosol generation, and a liquid-type particle collection setup was used. We demonstrate successful discrimination of SYTO82-dyed fluorescent bacterial cells from other residue particles in a continuous and real-time manner. In comparison with traditional microscopy cell counting and colony culture methods, this micro-optofluidic platform is not only more accurate in terms of the detection efficiency for airborne microorganisms but it also provides additional information on the total particle number concentration.
Jeong, Youngmo; Kim, Jonghyun; Yeom, Jiwoon; Lee, Chang-Kun; Lee, Byoungho
2015-12-10
In this paper, we develop a real-time depth controllable integral imaging system. With a high-frame-rate camera and a focus controllable lens, light fields from various depth ranges can be captured. According to the image plane of the light field camera, the objects in virtual and real space are recorded simultaneously. The captured light field information is converted to the elemental image in real time without pseudoscopic problems. In addition, we derive characteristics and limitations of the light field camera as a 3D broadcasting capturing device with precise geometry optics. With further analysis, the implemented system provides more accurate light fields than existing devices without depth distortion. We adapt an f-number matching method at the capture and display stage to record a more exact light field and solve depth distortion, respectively. The algorithm allows the users to adjust the pixel mapping structure of the reconstructed 3D image in real time. The proposed method presents a possibility of a handheld real-time 3D broadcasting system in a cheaper and more applicable way as compared to the previous methods. PMID:26836855
Structural damage evolution assessment using the regularised time step integration method
NASA Astrophysics Data System (ADS)
Chen, Hua-Peng; Maung, Than Soe
2014-09-01
This paper presents an approach to identify both the location and severity evolution of damage in engineering structures directly from measured dynamic response data. A relationship between the change in structural parameters such as stiffness caused by structural damage development and the measured dynamic response data such as accelerations is proposed, on the basis of the governing equations of motion for the original and damaged structural systems. Structural damage parameters associated with time are properly chosen to reflect both the location and severity development over time of damage in a structure. Basic equations are provided to solve the chosen time-dependent damage parameters, which are constructed by using the Newmark time step integration method without requiring a modal analysis procedure. The Tikhonov regularisation method incorporating the L-curve criterion for determining the regularisation parameter is then employed to reduce the influence of measurement errors in dynamic response data and then to produce stable solutions for structural damage parameters. Results for two numerical examples with various simulated damage scenarios show that the proposed method can accurately identify the locations of structural damage and correctly assess the evolution of damage severity from information on vibration measurements with uncertainties.
Efficient solution of time-domain boundary integral equations arising in sound-hard scattering
NASA Astrophysics Data System (ADS)
Veit, Alexander; Merta, Michal; Zapletal, Jan; Lukáš, Dalibor
2016-08-01
We consider the efficient numerical solution of the three-dimensional wave equation with Neumann boundary conditions via time-domain boundary integral equations. A space-time Galerkin method with $C^\\infty$-smooth, compactly supported basis functions in time and piecewise polynomial basis functions in space is employed. We discuss the structure of the system matrix and its efficient parallel assembly. Different preconditioning strategies for the solution of the arising systems with block Hessenberg matrices are proposed and investigated numerically. Furthermore, a C++ implementation parallelized by OpenMP and MPI in shared and distributed memory, respectively, is presented. The code is part of the boundary element library BEM4I. Results of numerical experiments including convergence and scalability tests up to a thousand cores on a cluster are provided. The presented implementation shows good parallel scalability of the system matrix assembly. Moreover, the proposed algebraic preconditioner in combination with the FGMRES solver leads to a significant reduction of the computational time.
An integrated analysis of phenotypic selection on insect body size and development time.
Eck, Daniel J; Shaw, Ruth G; Geyer, Charles J; Kingsolver, Joel G
2015-09-01
Most studies of phenotypic selection do not estimate selection or fitness surfaces for multiple components of fitness within a unified statistical framework. This makes it difficult or impossible to assess how selection operates on traits through variation in multiple components of fitness. We describe a new generation of aster models that can evaluate phenotypic selection by accounting for timing of life-history transitions and their effect on population growth rate, in addition to survival and reproductive output. We use this approach to estimate selection on body size and development time for a field population of the herbivorous insect, Manduca sexta (Lepidoptera: Sphingidae). Estimated fitness surfaces revealed strong and significant directional selection favoring both larger adult size (via effects on egg counts) and more rapid rates of early larval development (via effects on larval survival). Incorporating the timing of reproduction and its influence on population growth rate into the analysis resulted in larger values for size in early larval development at which fitness is maximized, and weaker selection on size in early larval development. These results illustrate how the interplay of different components of fitness can influence selection on size and development time. This integrated modeling framework can be readily applied to studies of phenotypic selection via multiple fitness components in other systems. PMID:26257167
Dose-response-time modelling: Second-generation turnover model with integral feedback control.
Andersson, Robert; Jirstrand, Mats; Peletier, Lambertus; Chappell, Michael J; Evans, Neil D; Gabrielsson, Johan
2016-01-01
This study presents a dose-response-time (DRT) analysis based on a large preclinical biomarker dataset on the interaction between nicotinic acid (NiAc) and free fatty acids (FFA). Data were collected from studies that examined different rates, routes, and modes of NiAc provocations on the FFA time course. All information regarding the exposure to NiAc was excluded in order to demonstrate the utility of a DRT model. Special emphasis was placed on the selection process of the biophase model. An inhibitory Imax-model, driven by the biophase amount, acted on the turnover rate of FFA. A second generation NiAc/FFA model, which encompasses integral (slow buildup of tolerance - an extension of the previously used NiAc/FFA turnover models) and moderator (rapid and oscillatory) feedback control, was simultaneously fitted to all time courses in normal rats. The integral feedback control managed to capture an observed 90% adaptation (i.e., almost a full return to baseline) when 10 days constant-rate infusion protocols of NiAc were used. The half-life of the adaptation process had a 90% prediction interval between 3.5-12 in the present population. The pharmacodynamic parameter estimates were highly consistent when compared to an exposure-driven analysis, partly validating the DRT modelling approach and suggesting the potential of DRT analysis in areas where exposure data are not attainable. Finally, new numerical algorithms, which rely on sensitivity equations to robustly and efficiently compute the gradients in the parameter optimization, were successfully used for the mixed-effects approach in the parameter estimation. PMID:26529383
Real-Time Baseline Error Estimation and Correction for GNSS/Strong Motion Seismometer Integration
NASA Astrophysics Data System (ADS)
Li, C. Y. N.; Groves, P. D.; Ziebart, M. K.
2014-12-01
Accurate and rapid estimation of permanent surface displacement is required immediately after a slip event for earthquake monitoring or tsunami early warning. It is difficult to achieve the necessary accuracy and precision at high- and low-frequencies using GNSS or seismometry alone. GNSS and seismic sensors can be integrated to overcome the limitations of each. Kalman filter algorithms with displacement and velocity states have been developed to combine GNSS and accelerometer observations to obtain the optimal displacement solutions. However, the sawtooth-like phenomena caused by the bias or tilting of the sensor decrease the accuracy of the displacement estimates. A three-dimensional Kalman filter algorithm with an additional baseline error state has been developed. An experiment with both a GNSS receiver and a strong motion seismometer mounted on a movable platform and subjected to known displacements was carried out. The results clearly show that the additional baseline error state enables the Kalman filter to estimate the instrument's sensor bias and tilt effects and correct the state estimates in real time. Furthermore, the proposed Kalman filter algorithm has been validated with data sets from the 2010 Mw 7.2 El Mayor-Cucapah Earthquake. The results indicate that the additional baseline error state can not only eliminate the linear and quadratic drifts but also reduce the sawtooth-like effects from the displacement solutions. The conventional zero-mean baseline-corrected results cannot show the permanent displacements after an earthquake; the two-state Kalman filter can only provide stable and optimal solutions if the strong motion seismometer had not been moved or tilted by the earthquake. Yet the proposed Kalman filter can achieve the precise and accurate displacements by estimating and correcting for the baseline error at each epoch. The integration filters out noise-like distortions and thus improves the real-time detection and measurement capability
An integrated approach using high time-resolved tools to study the origin of aerosols.
Di Gilio, A; de Gennaro, G; Dambruoso, P; Ventrella, G
2015-10-15
Long-range transport of natural and/or anthropogenic particles can contribute significantly to PM10 and PM2.5 concentrations and some European cities often fail to comply with PM daily limit values due to the additional impact of particles from remote sources. For this reason, reliable methodologies to identify long-range transport (LRT) events would be useful to better understand air pollution phenomena and support proper decision-making. This study explores the potential of an integrated and high time-resolved monitoring approach for the identification and characterization of local, regional and long-range transport events of high PM. In particular, the goal of this work was also the identification of time-limited event. For this purpose, a high time-resolved monitoring campaign was carried out at an urban background site in Bari (southern Italy) for about 20 days (1st-20th October 2011). The integration of collected data as the hourly measurements of inorganic ions in PM2.5 and their gas precursors and of the natural radioactivity, in addition to the analyses of aerosol maps and hourly back trajectories (BT), provided useful information for the identification and chemical characterization of local sources and trans-boundary intrusions. Non-sea salt (nss) sulfate levels were found to increase when air masses came from northeastern Europe and higher dispersive conditions of the atmosphere were detected. Instead, higher nitrate and lower nss-sulfate concentrations were registered in correspondence with air mass stagnation and attributed to local traffic source. In some cases, combinations of local and trans-boundary sources were observed. Finally, statistical investigations such as the principal component analysis (PCA) applied on hourly ion concentrations and the cluster analyses, the Potential Source Contribution Function (PSCF) and the Concentration Weighted Trajectory (CWT) models computed on hourly back-trajectories enabled to complete a cognitive framework
NASA Astrophysics Data System (ADS)
Roellig, Mike; Meier, Karsten; Metasch, Rene
2010-11-01
The recent development of 3D-integrated electronic packages is characterized by the need to increase the diversity of functions and to miniaturize. Currently many 3D-integration concepts are being developed and all of them demand new materials, new designs and new processing technologies. The combination of simulation and experimental investigation becomes increasingly accepted since simulations help to shorten the R&D cycle time and reduce costs. Numerical calculations like the Finite-Element-Method are strong tools to calculate stress conditions in electronic packages resulting from thermal strains due to the manufacturing process and environmental loads. It is essential for the application of numerical calculations that the material data is accurate and describes sufficiently the physical behaviour. The developed machine allows the measurement of time and temperature dependent micromechanical properties of solder joints. Solder joints, which are used to mechanically and electrically connect different packages, are physically measured as they leave the process. This allows accounting for process influences, which may change material properties. Additionally, joint sizes and metallurgical interactions between solder and under bump metallization can be respected by this particular measurement. The measurement allows the determination of material properties within a temperature range of 20° C-200° C. Further, the time dependent creep deformation can be measured within a strain-rate range of 10-31/s-10-81/s. Solder alloys based on Sn-Ag/Sn-Ag-Cu with additionally impurities and joint sizes down to O/ 200 μm were investigated. To finish the material characterization process the material model coefficient were extracted by FEM-Simulation to increase the accuracy of data.
Lagrangian and Hamiltonian structures in an integrable hierarchy and space-time duality
NASA Astrophysics Data System (ADS)
Avan, Jean; Caudrelier, Vincent; Doikou, Anastasia; Kundu, Anjan
2016-01-01
We define and illustrate the novel notion of dual integrable hierarchies, on the example of the nonlinear Schrödinger (NLS) hierarchy. For each integrable nonlinear evolution equation (NLEE) in the hierarchy, dual integrable structures are characterized by the fact that the zero-curvature representation of the NLEE can be realized by two Hamiltonian formulations stemming from two distinct choices of the configuration space, yielding two inequivalent Poisson structures on the corresponding phase space and two distinct Hamiltonians. This is fundamentally different from the standard bi-Hamiltonian or generally multitime structure. The first formulation chooses purely space-dependent fields as configuration space; it yields the standard Poisson structure for NLS. The other one is new: it chooses purely time-dependent fields as configuration space and yields a different Poisson structure at each level of the hierarchy. The corresponding NLEE becomes a space evolution equation. We emphasize the role of the Lagrangian formulation as a unifying framework for deriving both Poisson structures, using ideas from covariant field theory. One of our main results is to show that the two matrices of the Lax pair satisfy the same form of ultralocal Poisson algebra (up to a sign) characterized by an r-matrix structure, whereas traditionally only one of them is involved in the classical r-matrix method. We construct explicit dual hierarchies of Hamiltonians, and Lax representations of the triggered dynamics, from the monodromy matrices of either Lax matrix. An appealing procedure to build a multi-dimensional lattice of Lax pair, through successive uses of the dual Poisson structures, is briefly introduced.
Neuronal Spike Timing Adaptation Described with a Fractional Leaky Integrate-and-Fire Model
Teka, Wondimu; Marinov, Toma M.; Santamaria, Fidel
2014-01-01
The voltage trace of neuronal activities can follow multiple timescale dynamics that arise from correlated membrane conductances. Such processes can result in power-law behavior in which the membrane voltage cannot be characterized with a single time constant. The emergent effect of these membrane correlations is a non-Markovian process that can be modeled with a fractional derivative. A fractional derivative is a non-local process in which the value of the variable is determined by integrating a temporal weighted voltage trace, also called the memory trace. Here we developed and analyzed a fractional leaky integrate-and-fire model in which the exponent of the fractional derivative can vary from 0 to 1, with 1 representing the normal derivative. As the exponent of the fractional derivative decreases, the weights of the voltage trace increase. Thus, the value of the voltage is increasingly correlated with the trajectory of the voltage in the past. By varying only the fractional exponent, our model can reproduce upward and downward spike adaptations found experimentally in neocortical pyramidal cells and tectal neurons in vitro. The model also produces spikes with longer first-spike latency and high inter-spike variability with power-law distribution. We further analyze spike adaptation and the responses to noisy and oscillatory input. The fractional model generates reliable spike patterns in response to noisy input. Overall, the spiking activity of the fractional leaky integrate-and-fire model deviates from the spiking activity of the Markovian model and reflects the temporal accumulated intrinsic membrane dynamics that affect the response of the neuron to external stimulation. PMID:24675903
Near real-time, on-the-move multisensor integration and computing framework
NASA Astrophysics Data System (ADS)
Burnette, Chris; Schneider, Matt; Agarwal, Sanjeev; Deterline, Diane; Geyer, Chris; Phan, Chung D.; Lydic, Richard M.; Green, Kevin; Swett, Bruce
2015-05-01
Implanted mines and improvised devices are a persistent threat to Warfighters. Current Army countermine missions for route clearance need on-the-move standoff detection to improve the rate of advance. Vehicle-based forward looking sensors such as electro-optical and infrared (EO/IR) devices can be used to identify potential threats in near real-time (NRT) at safe standoff distance to support route clearance missions. The MOVERS (Micro-Cloud for Operational, Vehicle-Based EO-IR Reconnaissance System) is a vehicle-based multi-sensor integration and exploitation system that ingests and processes video and imagery data captured from forward-looking EO/IR and thermal sensors, and also generates target/feature alerts, using the Video Processing and Exploitation Framework (VPEF) "plug and play" video processing toolset. The MOVERS Framework provides an extensible, flexible, and scalable computing and multi-sensor integration GOTS framework that enables the capability to add more vehicles, sensors, processors or displays, and a service architecture that provides low-latency raw video and metadata streams as well as a command and control interface. Functionality in the framework is exposed through the MOVERS SDK which decouples the implementation of the service and client from the specific communication protocols.
NASA Technical Reports Server (NTRS)
Agrawal, Gagan; Sussman, Alan; Saltz, Joel
1993-01-01
Scientific and engineering applications often involve structured meshes. These meshes may be nested (for multigrid codes) and/or irregularly coupled (called multiblock or irregularly coupled regular mesh problems). A combined runtime and compile-time approach for parallelizing these applications on distributed memory parallel machines in an efficient and machine-independent fashion was described. A runtime library which can be used to port these applications on distributed memory machines was designed and implemented. The library is currently implemented on several different systems. To further ease the task of application programmers, methods were developed for integrating this runtime library with compilers for HPK-like parallel programming languages. How this runtime library was integrated with the Fortran 90D compiler being developed at Syracuse University is discussed. Experimental results to demonstrate the efficacy of our approach are presented. A multiblock Navier-Stokes solver template and a multigrid code were experimented with. Our experimental results show that our primitives have low runtime communication overheads. Further, the compiler parallelized codes perform within 20 percent of the code parallelized by manually inserting calls to the runtime library.
Integration of Kepler with ROADNet: Visual Dataflow Design with Real-time Geophysical Data
NASA Astrophysics Data System (ADS)
Fricke, T. T.; Ludaescher, B.; Altintas, I.; Lindquist, K. G.; Hansen, T. S.; Rajasekar, A.; Vernon, F. L.; Orcutt, J.
2004-12-01
The ROADNet project concentrates real-time data from a wide variety of signal domains, providing a reliable platform to store and transport these data. Ptolemy is a general purpose visual programming environment in which work flows on data streams can be constructed by connecting general purpose components. The Kepler scientific workflow system extends Ptolemy to approach design and automation of scientific data analysis tasks. In this work we discuss our integration of ROADNet (and the Antelope platform on which ROADNet is based in part) with the Ptolemy environment. We have produced interface components that allow someone using the Kepler scientific workflow system to readily use ROADNet data resources. Presently we have working components to gather real-time waveform and image data from ROADNet object ring buffers, and we are working to provide the ability to perform Datascope database queries from Kepler. The Kepler project, including the Antelope interface, is entirely free and open-source, and will run on any platform where Java is available. We discuss existing applications in addition to possible future directions, such as coherent array processing, event detection, and online stream processing. A major advantage of the Ptolemy environment is the ease with which it may be used for rapid prototyping of analyses by even inexperienced users. For instance, a user can drag-and-drop an Orb Waveform Source component and several general purpose analysis and display components, connect them visually, and immediately perform an analysis on real-time data.
Rhodes, Ryan E; Courneya, Kerry S; Blanchard, Chris M; Plotnikoff, Ronald C
2007-01-01
Background Walking is the primary focus of population-based physical activity initiatives but a theoretical understanding of this behaviour is still elusive. The purpose of this study was to integrate personality, the perceived environment, and planning into a theory of planned behaviour (TPB) framework to predict leisure-time walking. Methods Participants were a random sample (N = 358) of Canadian adults who completed measures of the TPB, planning, perceived neighbourhood environment, and personality at Time 1 and self-reported walking behaviour two months later. Results Analyses using structural equation modelling provided evidence that leisure-time walking is largely predicted by intention (standardized effect = .42) with an additional independent contribution from proximity to neighbourhood retail shops (standardized effect = .18). Intention, in turn, was predicted by attitudes toward walking and perceived behavioural control. Effects of perceived neighbourhood aesthetics and walking infrastructure on walking were mediated through attitudes and intention. Moderated regression analysis showed that the intention-walking relationship was moderated by conscientiousness and proximity to neighbourhood recreation facilities but not planning. Conclusion Overall, walking behaviour is theoretically complex but may best be addressed at a population level by facilitating strong intentions in a receptive environment even though individual differences may persist. PMID:17974022
Edwards, R.
1988-05-02
The Decision System Research Section of the Oak Ridge National Laboratory (ORNL) is assisting the Deployment Directorate (formerly the Joint Deployment Agency) of the US Transportation Command (USTRANSCOM) in identifying and evaluating opportunities for improving the automation support used in deliberate and time-critical deployment planning. USTRANSCOM, which is a unified command (i.e., personnel are drawn from all services), was created in the fall of 1987 to consolidate the functions of the former Military Transportation Operating Agencies (the Military Airlift Command, the Military Traffic Management Command, and the Military Sealift Command). An important factor justifying creation of USTRANSCOM, was the possibility of combining and improving coordination in deployment planning between the organizations responsible for strategic transportation activities during times of crisis. This report, the second in a series to be produced in the course of the ORNL study, presents three possibilities for integrating deliberate and time-sensitive planning. Two proposals recommended for use by MTMC and MSC build on cooperative planning initiatives already in progress in the two commands. A unique application of relative probabilistic measures is a key element in a proposal for improving MTMC/MAC airlift planning. 35 refs., 1 tab.
Gullapalli, Ramachandra R.; Tabouillot, Tristan; Mathura, Rishi; Dangaria, Jhanvi H.; Butler, Peter J.
2011-01-01
Cells respond to forces through coordinated biochemical signaling cascades that originate from changes in single-molecule structure and dynamics and proceed to large-scale changes in cellular morphology and protein expression. To enable experiments that determine the molecular basis of mechanotransduction over these large time and length scales, we construct a confocal molecular dynamics microscope (CMDM). This system integrates total-internal-reflection fluorescence (TIRF), epifluorescence, differential interference contrast (DIC), and 3-D deconvolution imaging modalities with time-correlated single-photon counting (TCSPC) instrumentation and an optical trap. Some of the structures hypothesized to be involved in mechanotransduction are the glycocalyx, plasma membrane, actin cytoskeleton, focal adhesions, and cell-cell junctions. Through analysis of fluorescence fluctuations, single-molecule spectroscopic measurements [e.g., fluorescence correlation spectroscopy (FCS) and time-resolved fluorescence] can be correlated with these subcellular structures in adherent endothelial cells subjected to well-defined forces. We describe the construction of our multimodal microscope in detail and the calibrations necessary to define molecular dynamics in cell and model membranes. Finally, we discuss the potential applications of the system and its implications for the field of mechanotransduction. PMID:17343487
Reverberation time measurement using integrated impulse response and sweep sine excitation
NASA Astrophysics Data System (ADS)
Nabuco, Marco; Brando, Paulo
2002-11-01
As the capacity and speed of digital processing systems becomes much higher, the integrated impulsive response for reverberation time measurements by the indirect method also becomes more feasible and faster. The MLS technique to obtain the impulse response for LTI has been developed during the last several years and it is very well reported by the bibliography. Some frequency analyzers available in the market are capable to generate and process MLS to get the impulse responses very easily. Sometimes, when the room to be tested is very reverberant, sequences of higher order and a certain number of average are necessary to assure acceptable signal-to-noise ratio. The sweep sine technique or the deconvolution method to obtain impulsive responses presents many new advantages, most of them still reported in various technical documents. This paper presents the results of application of this technique to measure the reverberation time in two different reverberation rooms. Comparisons with MLS, ensemble, and reverberation time averages are presented. The sweep sine technique repeatability was verified in a reverberation chamber for a polyurethane foam sample and showed smaller standard deviations when compared with other techniques. (To be presented in Portuguese.)
NASA Technical Reports Server (NTRS)
Jensen, E. Douglas
1988-01-01
Alpha is a new kind of operating system that is unique in two highly significant ways. First, it is decentralized transparently providing reliable resource management across physically dispersed nodes, so that distributed applications programming can be done largely as though it were centralized. And second, it provides comprehensive, high technology support for real-time system integration and operation, an application area which consists predominately of aperiodic activities having critical time constraints such as deadlines. Alpha is extremely adaptable so that it can be easily optimized for a wide range of problem-specific functionality, performance, and cost. Alpha is the first systems effort of the Archons Project, and the prototype was created at Carnegie-Mellon University directly on modified Sun multiprocessor workstation hardware. It has been demonstrated with a real-time C(sup 2) application. Continuing research is leading to a series of enhanced follow-ons to Alpha; these are portable but initially hosted on Concurrent's MASSCOMP line of multiprocessor products.
Finite Element Analysis Of An Axially Moving Beam, Part I: Time Integration
NASA Astrophysics Data System (ADS)
Stylianou, M.; Tabarrok, B.
1994-12-01
Axially moving materials arise in problems associated with spacecraft antennas, pipes conveying fluid and telescopic robotic manipulators. Axially moving beams are a special class of axially moving materials, in which the axially moving material is modelled as a slender beam and the mechanism of elastic deformation is transverse bending. The mass of this system is not constant and the general analytical solution to the equation of motion is not known. In this study, numerical solutions are obtained using finite element analysis. However, instead of following the obvious (but cumbersome) approach of using fixed-size elements and increasing their number, in a step-wise fashion, as mass elements enter the domain of interest, a more elegant approach is followed wherein the number of elements is fixed, while the sizes of the elements change with time. To this end, a variable-domain beam finite element the size of which is a prescribed function of time is formulated in Part I. The accuracy of this variable-domain beam element is demonstrated through the time-integration of equations of motion using various extrusion profiles. The effects of wall flexibility, tip mass, and high frequency axial motion perturbations to the transverse response of the flexible extendible beam are also examined.
Time-lapsed integrated Raman and angular scattering microscopy of single cells
NASA Astrophysics Data System (ADS)
Shipp, Dustin W.; Berger, Andrew J.
2011-03-01
Integrated Raman- and Angular-scatteringMicroscopy (IRAM) combines two light scattering techniques to make chemical and morphological measurements of intact, single cells without the use of external labeling. IRAM has previously demonstrated its ability to differentiate between activated and non-activated CD8+ T cells based on both chemical and morphological differences. Activated cells showed an increase in protein and lipid content as well as an increase in the size and number of 0.5-1.0 μm diameter scatterers (likely lysosomes). Recent improvements to the IRAM system enable studies over an extended period of time. The applications of IRAM to chemical and structural changes of single cells during biological processes and treatments will be discussed.
Evidence for CP violation in time-integrated D0→h(-)h(+) decay rates.
Aaij, R; Abellan Beteta, C; Adeva, B; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amhis, Y; Anderson, J; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Arrabito, L; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Bachmann, S; Back, J J; Bailey, D S; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bates, A; Bauer, C; Bauer, Th; Bay, A; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Benayoun, M; Bencivenni, G; Benson, S; Benton, J; Bernet, R; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blanks, C; Blouw, J; Blusk, S; Bobrov, A; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Büchler-Germann, A; Burducea, I; Bursche, A; Buytaert, J; Cadeddu, S; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carson, L; Carvalho Akiba, K; Casse, G; Cattaneo, M; Cauet, Ch; Charles, M; Charpentier, Ph; Chiapolini, N; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Collins, P; Comerma-Montells, A; Constantin, F; Contu, A; Cook, A; Coombes, M; Corti, G; Cowan, G A; Currie, R; D'Ambrosio, C; David, P; David, P N Y; De Bonis, I; De Capua, S; De Cian, M; De Lorenzi, F; De Miranda, J M; De Paula, L; De Simone, P; Decamp, D; Deckenhoff, M; Degaudenzi, H; Del Buono, L; Deplano, C; Derkach, D; Deschamps, O; Dettori, F; Dickens, J; Dijkstra, H; Diniz Batista, P; Domingo Bonal, F; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Dzhelyadin, R; Dziurda, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisele, F; Eisenhardt, S; Ekelhof, R; Eklund, L; Elsasser, Ch; Elsby, D; Esperante Pereira, D; Estève, L; Falabella, A; Fanchini, E; Färber, C; Fardell, G; Farinelli, C; Farry, S; Fave, V; Fernandez Albor, V; Ferro-Luzzi, M; Filippov, S; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Frank, M; Frei, C; Frosini, M; Furcas, S; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garnier, J-C; Garofoli, J; Garra Tico, J; Garrido, L; Gascon, D; Gaspar, C; Gauvin, N; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Haefeli, G; Haen, C; Haines, S C; Hampson, T; Hansmann-Menzemer, S; Harji, R; Harnew, N; Harrison, J; Harrison, P F; Hartmann, T; He, J; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicks, E; Holubyev, K; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Huston, R S; Hutchcroft, D; Hynds, D; Iakovenko, V; Ilten, P; Imong, J; Jacobsson, R; Jaeger, A; Jahjah Hussein, M; Jans, E; Jansen, F; Jaton, P; Jean-Marie, B; Jing, F; John, M; Johnson, D; Jones, C R; Jost, B; Kaballo, M; Kandybei, S; Karacson, M; Karbach, T M; Keaveney, J; Kenyon, I R; Kerzel, U; Ketel, T; Keune, A; Khanji, B; Kim, Y M; Knecht, M; Koopman, R; Koppenburg, P; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kruzelecki, K; Kucharczyk, M; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leroy, O; Lesiak, T; Li, L; Li Gioi, L; Lieng, M; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; von Loeben, J; Lopes, J H; Lopez Asamar, E; Lopez-March, N; Lu, H; Luisier, J; Mac Raighne, A; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Magnin, J; Malde, S; Mamunur, R M D; Manca, G; Mancinelli, G; Mangiafave, N; Marconi, U; Märki, R; Marks, J; Martellotti, G; Martens, A; Martin, L; Martín Sánchez, A; Martinez Santos, D; Massafferri, A; Mathe, Z; Matteuzzi, C; Matveev, M; Maurice, E; Maynard, B; Mazurov, A; McGregor, G; McNulty, R; Meissner, M; Merk, M; Merkel, J; Messi, R; Miglioranzi, S; Milanes, D A; Minard, M-N; Molina Rodriguez, J; Monteil, S; Moran, D; Morawski, P; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Muster, B; Musy, M; Mylroie-Smith, J; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Nedos, M; Needham, M; Neufeld, N; Nguyen-Mau, C; Nicol, M; Niess, V; Nikitin, N; Nomerotski, A; Novoselov, A; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Owen, P; Pal, K; Palacios, J; Palano, A; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Paterson, S K; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perego, D L; Perez Trigo, E; Pérez-Calero Yzquierdo, A; Perret, P; Perrin-Terrin, M; Pessina, G; Petrella, A; Petrolini, A; Phan, A; Picatoste Olloqui, E; Pie Valls, B; Pietrzyk, B; Pilař, T; Pinci, D; Plackett, R; Playfer, S; Plo Casasus, M; Polok, G; Poluektov, A; Polycarpo, E; Popov, D; Popovici, B; Potterat, C; Powell, A; Prisciandaro, J; Pugatch, V; Navarro, A Puig; Qian, W; Rademacker, J H; Rakotomiaramanana, B; Rangel, M S; Raniuk, I; Raven, G; Redford, S; Reid, M M; dos Reis, A C; Ricciardi, S; Rinnert, K; Roa Romero, D A; Robbe, P; Rodrigues, E; Rodrigues, F; Rodriguez Perez, P; Rogers, G J; Roiser, S; Romanovsky, V; Rosello, M; Rouvinet, J; Ruf, T; Ruiz, H; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salzmann, C; Sannino, M; Santacesaria, R; Santamarina Rios, C; Santinelli, R; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schaack, P; Schiller, M; Schleich, S; Schlupp, M; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M-H; Schwemmer, R; Sciascia, B; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Sepp, I; Serra, N; Serrano, J; Seyfert, P; Shapkin, M; Shapoval, I; Shatalov, P; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Skwarnicki, T; Smith, A C; Smith, N A; Smith, E; Sobczak, K; Soler, F J P; Solomin, A; Soomro, F; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stoica, S; Stone, S; Storaci, B; Straticiuc, M; Straumann, U; Subbiah, V K; Swientek, S; Szczekowski, M; Szczypka, P; Szumlak, T; T'jampens, S; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Topp-Joergensen, S; Torr, N; Tournefier, E; Tran, M T; Tsaregorodtsev, A; Tuning, N; Ubeda Garcia, M; Ukleja, A; Urquijo, P; Uwer, U; Vagnoni, V; Valenti, G; Vazquez Gomez, R; Vazquez Regueiro, P; Vecchi, S; Velthuis, J J; Veltri, M; Viaud, B; Videau, I; Vilasis-Cardona, X; Visniakov, J; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Voss, H; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Webber, A D; Websdale, D; Whitehead, M; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wishahi, J; Witek, M; Witzeling, W; Wotton, S A; Wyllie, K; Xie, Y; Xing, F; Xing, Z; Yang, Z; Young, R; Yushchenko, O; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhong, L; Zverev, E; Zvyagin, A
2012-03-16
A search for time-integrated CP violation in D(0)→h(-)h(+) (h=K, π) decays is presented using 0.62 fb(-1) of data collected by LHCb in 2011. The flavor of the charm meson is determined by the charge of the slow pion in the D(*+)→D(0)π(+) and D(*-)→D[over ¯](0)π(-) decay chains. The difference in CP asymmetry between D(0)→K(-)K(+) and D(0)→π(-)π(+), ΔA(CP)≡A(CP)(K(-)K(+))-A(CP)(π(-)π(+)), is measured to be [-0.82±0.21(stat)±0.11(syst)]%. This differs from the hypothesis of CP conservation by 3.5 standard deviations. PMID:22540460
De Cordt, S F; Hendrickx, M E; Maesmans, G J; Tobback, P P
1994-02-01
For the immobilization of Bacillus licheniformis alpha-amylase to porous glass beads, the performances of three possible linking agents, glutaric dialdehyde, benzoquinone and s-trichlorotriazine were assessed in respect of the protein yield, the enzymic activity and the thermostability of the immobilized enzyme. These three properties are to be evaluated in view of the possible use of the enzyme preparations as time-temperature-integrators (TTIs) for assessing the severity of heat pasteurization or sterilization processes of food or pharmaceuticals. All three linkers improved the enzyme's resistance to irreversible heat inactivation to a similar extent and in each case biphasic inactivation kinetics were observed, whereas the dissolved B. licheniformis alpha-amylase showed a simple first order decay. The immobilization yield, measured as protein per carrier weight, did not differ markedly for the three linkers, although the enzymic activity of the glutaric dialdehyde-linked enzyme was lower than that of the benzoquinone- and s-trichlorotriazine-linked preparations. PMID:7764538
Image restoration of hybrid time delay and integration camera system with residual motion
NASA Astrophysics Data System (ADS)
Zheng, Zhenzhen; Wu, Jiagu; Feng, Huajun; Xu, Zhihai; Li, Qi; Chen, Yueting
2011-06-01
In this paper, we present a hybrid system for time delay and integration (TDI) image restoration. Images are degraded by residual motion, which distorts and blurs the TDI images during exposures and excludes the along-track scanning motion. The motion trajectory is estimated from the image sequence captured by an auxiliary high-speed camera. In order to make the estimated results less sensitive to the imaging conditions and noise, a new method based on cross-correlation is introduced for motion estimation. Then geometric distortion of the TDI image is removed by choosing the correct blurred block according to the central of the corresponding motion trajectory and the final image is restored row by row with the Richardson-Lucy algorithm. Simulated and experimental results are given to prove the effectiveness of our system.
A time-temperature integrator based on fluorescent and polymorphic compounds
Gentili, Denis; Durso, Margherita; Bettini, Cristian; Manet, Ilse; Gazzano, Massimo; Capelli, Raffaella; Muccini, Michele; Melucci, Manuela; Cavallini, Massimiliano
2013-01-01
Despite the variety of functional properties of molecular materials, which make them of interest for a number of technologies, their tendency to form inhomogeneous aggregates in thin films and to self-organize in polymorphs are considered drawbacks for practical applications. Here, we report on the use of polymorphic molecular fluorescent thin films as time temperature integrators, a class of devices that monitor the thermal history of a product. The device is fabricated by patterning the fluorescent model compound thieno(bis)imide-oligothiophene. The fluorescence colour of the pattern changes as a consequence of an irreversible phase variation driven by temperature, and reveals the temperature at which the pattern was exposed. The experimental results are quantitatively analysed in the range 20–200°C and interpreted considering a polymorph recrystallization in the thin film. Noteworthy, the reported method is of general validity and can be extended to every compound featuring irreversible temperature-dependent change of fluorescence. PMID:24002421
A new device for collecting time-integrated water samples from springs and surface water bodies
Panno, S.V.; Krapac, I.G.; Keefer, D.A.
1998-01-01
A new device termed the 'seepage sampler' was developed to collect representative water samples from springs, streams, and other surface-water bodies. The sampler collects composite, time-integrated water samples over short (hours) or extended (weeks) periods without causing significant changes to the chemical composition of the samples. The water sample within the sampler remains at the ambient temperature of the water body and does not need to be cooled. Seepage samplers are inexpensive to construct and easy to use. A sampling program of numerous springs and/or streams can be designed at a relatively low cost through the use of these samplers. Transient solutes migrating through such flow systems, potentially unnoticed by periodic sampling, may be detected. In addition, the mass loading of solutes (e.g., agrichemicals) may be determined when seepage samplers are used in conjunction with discharge measurements.
Climatologically tuned reflectivity-rain rate relations and links to area-time integrals
NASA Technical Reports Server (NTRS)
Atlas, David; Rosenfeld, Daniel; Wolff, David B.
1990-01-01
An effort is made to determine relationships between reflectivity (Z) and rain rate (R) which are tuned to the local climatology. The development of such relations was motivated by the need to understand the role of precipitation in controlling general circulation and in affecting such phenomena as ENSO. Attention is given to methods of deriving such relations and how they are linked to area integral rainfall measurements. In essence, the relation is tuned so that the probability distribution of reflectivity, P(Z), replicates that of R over some predetermined space-time climatic domain. Thus, the accurate measurement of the average R over any smaller domain depends on how closely the sampled P(Z) approximates the climatic P(Z). The probability matching method used is a modification of the approach of Calheiros and Zawadzki (1987) and Rosenfeld (1980). The technique is applied to data from Germany and the eastern tropical Atlantic (GATE).
Nayak, Monalisha; Singh, Deepak; Singh, Himanshu; Kant, Rishi; Gupta, Ankur; Pandey, Shashank Shekhar; Mandal, Swarnasri; Ramanathan, Gurunath; Bhattacharya, Shantanu
2013-01-01
The extremely low limit of detection (LOD) posed by global food and water safety standards necessitates the need to perform a rapid process of integrated detection with high specificity, sensitivity and repeatability. The work reported in this article shows a microchip platform which carries out an ensemble of protocols which are otherwise carried in a molecular biology laboratory to achieve the global safety standards. The various steps in the microchip include pre-concentration of specific microorganisms from samples and a highly specific real time molecular identification utilizing a q-PCR process. The microchip process utilizes a high sensitivity antibody based recognition and an electric field mediated capture enabling an overall low LOD. The whole process of counting, sorting and molecular identification is performed in less than 4 hours for highly dilute samples. PMID:24253282
Electronics of an ion trap with integrated time-of-flight mass spectrometer
NASA Astrophysics Data System (ADS)
Schneider, Christian; Schowalter, Steven J.; Yu, Peter; Hudson, Eric R.
2016-01-01
Recently, we reported an ion trap experiment with an integrated time-of-flight mass spectrometer (TOFMS) [Phys. Rev. Appl. 2, 034013 (2014)] focussing on the improvement of mass resolution and detection limit due to sample preparation at millikelvin temperatures. The system utilizes a radio-frequency (RF) ion trap with asymmetric drive for storing and manipulating laser-cooled ions and features radial extraction into a compact $275$ mm long TOF drift tube. The mass resolution exceeds $m / \\Delta m = 500$, which provides isotopic resolution over the whole mass range of interest in current experiments and constitutes an improvement of almost an order of magnitude over other implementations. In this manuscript, we discuss the experimental implementation in detail, which is comprised of newly developed drive electronics for generating the required voltages to operate RF trap and TOFMS, as well as control electronics for regulating RF outputs and synchronizing the TOFMS extraction.
Rapid Ultrasound in Shock (RUSH) Velocity-Time Integral: A Proposal to Expand the RUSH Protocol.
Blanco, Pablo; Aguiar, Francisco Miralles; Blaivas, Michael
2015-09-01
Ultrasound assessment of patients in shock is becoming the standard of care in emergency and critical care settings worldwide. One of the most common protocols used for this assessment is the rapid ultrasound in shock (RUSH) examination. The RUSH protocol is a rapid evaluation of cardiac function, key vascular structures, and likely sources of hypotension. Stroke volume is an established important value to assess in the setting of shock, allowing the provider to predict the patient's response to treatment. However, the calculation of stroke volume or its surrogates is not part of any protocol, including RUSH. We propose the addition of ultrasound calculation of stroke volume or surrogates to the RUSH protocol and provide support for its utility and relative ease of calculation. The resulting product would be the RUSH velocity-time integral protocol. PMID:26283755
NASA Astrophysics Data System (ADS)
Nayak, Monalisha; Singh, Deepak; Singh, Himanshu; Kant, Rishi; Gupta, Ankur; Pandey, Shashank Shekhar; Mandal, Swarnasri; Ramanathan, Gurunath; Bhattacharya, Shantanu
2013-11-01
The extremely low limit of detection (LOD) posed by global food and water safety standards necessitates the need to perform a rapid process of integrated detection with high specificity, sensitivity and repeatability. The work reported in this article shows a microchip platform which carries out an ensemble of protocols which are otherwise carried in a molecular biology laboratory to achieve the global safety standards. The various steps in the microchip include pre-concentration of specific microorganisms from samples and a highly specific real time molecular identification utilizing a q-PCR process. The microchip process utilizes a high sensitivity antibody based recognition and an electric field mediated capture enabling an overall low LOD. The whole process of counting, sorting and molecular identification is performed in less than 4 hours for highly dilute samples.
Seasonal fractional integrated time series models for rainfall data in Nigeria
NASA Astrophysics Data System (ADS)
Yaya, Olaoluwa S.; Fashae, Olutoyin A.
2015-04-01
Rainfall variability, seasonality and extremity have a lot of consequences in planning and decision making of every sphere of human endeavour especially in Nigeria where majority of agricultural practices and planning is dependent on rainfed agriculture. For this reason, an extensive understanding of rainfall regime is an important prerequisite in such planning. We approach this work using time series approach. Seasonality and possibility of long-term dependence in rainfall data are considered, and these have significant effects in explaining the distribution of rainfall in each state of the six geopolitical zones of Nigeria. The estimated seasonal autoregressive fractionally integrated moving average (SARFIMA) model for each of the six rainfall zones was found to perform better in predicting rainfall distribution than the corresponding seasonal autoregressive moving average (SARMA) model in terms of minimum Akaike information criterion (AIC) and other model diagnostic measures.
NASA Technical Reports Server (NTRS)
Goorjian, Peter M.; Taflove, Allen
1992-01-01
The initial results for femtosecond electromagnetic soliton propagation and collision obtained from first principles, i.e., by a direct time integration of Maxwell's equations are reported. The time integration efficiently implements linear and nonlinear convolutions for the electric polarization and can take into account such quantum effects as Kerr and Raman interactions. The present approach is robust and should permit the modeling of 2D and 3D optical soliton propagation, scattering, and switching from the full-vector Maxwell's equations.
NASA Astrophysics Data System (ADS)
Cammi, C.; Panzeri, F.; Gulinatti, A.; Rech, I.; Ghioni, M.
2012-03-01
Emerged as a solid state alternative to photo multiplier tubes (PMTs), single-photon avalanche diodes (SPADs) are nowadays widely used in the field of single-photon timing applications. Custom technology SPADs assure remarkable performance, in particular a 10 counts/s dark count rate (DCR) at low temperature, a high photon detection efficiency (PDE) with a 50% peak at 550 nm and a 30 ps (full width at half maximum, FWHM) temporal resolution, even with large area devices, have been obtained. Over the past few years, the birth of novel techniques of analysis has led to the parallelization of the measurement systems and to a consequent increasing demand for the development of monolithic arrays of detectors. Unfortunately, the implementation of a multidimensional system is a challenging task from the electrical point of view; in particular, the avalanche current pick-up circuit, used to obtain the previously reported performance, has to be modified in order to enable high parallel temporal resolution, while minimizing the electrical crosstalk probability between channels. In the past, the problem has been solved by integrating the front-end electronics next to the photodetector, in order to reduce the parasitic capacitances and consequently the filtering action on the current signal of the SPAD, leading to an improvement of the timing jitter at higher threshold. This solution has been implemented by using standard complementary metal-oxide-semiconductor (CMOS) technologies, which, however, do not allow a complete control on the SPAD structure; for this reason the intrinsic performance of CMOS SPADs, such as DCR, PDE, and afterpulsing probability, are worse than those attainable with custom detectors. In this paper, we propose a pixel architecture, which enables the development of custom SPAD arrays in which every channel maintains the performance of the best single photodetector. The system relies on the integration of the timing signal pick-up circuit next to the
Cammi, C; Panzeri, F; Gulinatti, A; Rech, I; Ghioni, M
2012-03-01
Emerged as a solid state alternative to photo multiplier tubes (PMTs), single-photon avalanche diodes (SPADs) are nowadays widely used in the field of single-photon timing applications. Custom technology SPADs assure remarkable performance, in particular a 10 counts/s dark count rate (DCR) at low temperature, a high photon detection efficiency (PDE) with a 50% peak at 550 nm and a 30 ps (full width at half maximum, FWHM) temporal resolution, even with large area devices, have been obtained. Over the past few years, the birth of novel techniques of analysis has led to the parallelization of the measurement systems and to a consequent increasing demand for the development of monolithic arrays of detectors. Unfortunately, the implementation of a multidimensional system is a challenging task from the electrical point of view; in particular, the avalanche current pick-up circuit, used to obtain the previously reported performance, has to be modified in order to enable high parallel temporal resolution, while minimizing the electrical crosstalk probability between channels. In the past, the problem has been solved by integrating the front-end electronics next to the photodetector, in order to reduce the parasitic capacitances and consequently the filtering action on the current signal of the SPAD, leading to an improvement of the timing jitter at higher threshold. This solution has been implemented by using standard complementary metal-oxide-semiconductor (CMOS) technologies, which, however, do not allow a complete control on the SPAD structure; for this reason the intrinsic performance of CMOS SPADs, such as DCR, PDE, and afterpulsing probability, are worse than those attainable with custom detectors. In this paper, we propose a pixel architecture, which enables the development of custom SPAD arrays in which every channel maintains the performance of the best single photodetector. The system relies on the integration of the timing signal pick-up circuit next to the
NASA Astrophysics Data System (ADS)
Sun, Shuqian; Deng, Ye; Huang, Ningbo; Tang, Jian; Zhu, Ninghua; Li, Ming
2016-08-01
A tunable photonic temporal integrator based on Raman-gain assisted phase-shifted silicon Bragg gratings is proposed and theoretically demonstrated. The proposed temporal photonic integrator is constructed using a silicon-on-insulator (SOI) π-phase-shifted Bragg grating, with a 25 V reverse bias applied to the p-i-n rib waveguide. Key feature of our design is that the length of integration time window could be widely tuned by simply changing the optical power of the pump light and could be extended to very long when the pump power is approaching lasing threshold. In addition, this scheme also has the potential for on-chip integration with other silicon photonics components.
NASA Astrophysics Data System (ADS)
Tsaloglou, M.-N.; Loukas, C. M.; Ruano-López, J. M.; Morgan, H.; Mowlem, M. C.
2012-04-01
Quantitation of RNA sequences coding either for key metabolic proteins or highly conserved ribosomal subunits can provide insight on cell abundance, speciation and viability. Nucleic sequence-based amplification (NASBA) is an isothermal alternative to traditional nucleic acid amplification methods, such as quantitative PCR. We present here an integrated microfluidic sensor for cell concentration and lysis, RNA extraction/purification and quantitative RNA detection for environmental applications. The portable system uses pre-loaded reagents, stored as a gel on a disposable microfluidic cartridge, which is manufactured using low-cost injection moulding. The NASBA reaction is monitored real-time using a bespoke control unit which includes: an external fluorescence detector, three peristaltic micro-pumps, two heaters and temperature sensors, a battery, seven pin actuated micro-motors (or valve actuators), and an automatic cartridge insertion mechanism. The system has USB connectivity and none of the expensive components require replacing between reactions. Long-term storage of reagents is critically important for any diagnostic tool that will be used in the field, whether for medical or environmental analysis and has not been previously demonstrated for NASBA reagents on-chip. We have shown effective amplification, for as little as 500 cells of the toxic microalga Karenia brevis using reagents which had been preserved as a gel for 45 days. This is the first reported real-time isothermal RNA amplification using with on-chip preservation. Annealing of primers, amplification at 41 °C and real-time fluorescence detection using, also for the first time, an internal control and sequence-specific molecular beacons was all performed on our microfluidic sensor. Our results show excellent promise as a future quantitative tool of in situ phytoplankton analysis and other environmental applications, where long-term reagent storage and low power consumption is essential.
NASA Astrophysics Data System (ADS)
Jaithwa, Ishan
Deployment of smart grid technologies is accelerating. Smart grid enables bidirectional flows of energy and energy-related communications. The future electricity grid will look very different from today's power system. Large variable renewable energy sources will provide a greater portion of electricity, small DERs and energy storage systems will become more common, and utilities will operate many different kinds of energy efficiency. All of these changes will add complexity to the grid and require operators to be able to respond to fast dynamic changes to maintain system stability and security. This thesis investigates advanced control technology for grid integration of renewable energy sources and STATCOM systems by verifying them on real time hardware experiments using two different systems: d SPACE and OPAL RT. Three controls: conventional, direct vector control and the intelligent Neural network control were first simulated using Matlab to check the stability and safety of the system and were then implemented on real time hardware using the d SPACE and OPAL RT systems. The thesis then shows how dynamic-programming (DP) methods employed to train the neural networks are better than any other controllers where, an optimal control strategy is developed to ensure effective power delivery and to improve system stability. Through real time hardware implementation it is proved that the neural vector control approach produces the fastest response time, low overshoot, and, the best performance compared to the conventional standard vector control method and DCC vector control technique. Finally the entrepreneurial approach taken to drive the technologies from the lab to market via ORANGE ELECTRIC is discussed in brief.
Embedded Lensing Time Delays, the Fermat Potential, and the Integrated Sachs-Wolfe Effect
NASA Astrophysics Data System (ADS)
Chen, Bin; Kantowski, Ronald; Dai, Xinyu
2015-05-01
We derive the Fermat potential for a spherically symmetric lens embedded in a Friedman-Lemaître-Robertson-Walker cosmology and use it to investigate the late-time integrated Sachs-Wolfe (ISW) effect, i.e., secondary temperature fluctuations in the cosmic microwave background (CMB) caused by individual large-scale clusters and voids. We present a simple analytical expression for the temperature fluctuation in the CMB across such a lens as a derivative of the lens’ Fermat potential. This formalism is applicable to both linear and nonlinear density evolution scenarios, to arbitrarily large density contrasts, and to all open and closed background cosmologies. It is much simpler to use and makes the same predictions as conventional approaches. In this approach the total temperature fluctuation can be split into a time-delay part and an evolutionary part. Both parts must be included for cosmic structures that evolve and both can be equally important. We present very simple ISW models for cosmic voids and galaxy clusters to illustrate the ease of use of our formalism. We use the Fermat potentials of simple cosmic void models to compare predicted ISW effects with those recently extracted from WMAP and Planck data by stacking large cosmic voids using the aperture photometry method. If voids in the local universe with large density contrasts are no longer evolving we find that the time delay contribution alone predicts values consistent with the measurements. However, we find that for voids still evolving linearly, the evolutionary contribution cancels a significant part of the time delay contribution and results in predicted signals that are much smaller than recently observed.
Ellouze, M; Augustin, J-C
2010-03-31
The objective of this study was to evaluate (eO), a biological time temperature integrator (TTI) as a quality and safety indicator for ground beef packed under modified atmosphere and spiced cooked chicken slices packed under modified atmosphere. Storage trials and challenge tests were thus performed on several batches of the studied food to monitor and model the behavior of Listeria monocytogenes, Salmonella, Staphylococcus aureus and the indigenous food flora. Then, two different prototypes of the TTI (eO) were set and manufactured according to the studied products shelf lives. The TTI evolution with time at static and dynamic temperatures was monitored and modeled. Finally, exposure assessment models were set and used under several realistic storage profiles to assess the distributions of the concentration of the indigenous food flora and the distributions of the increase in the pathogens populations obtained at the end of the product shelf life or at the end point of the TTI, taking into account the TTIs batch variability. Results showed that in case of poor storage conditions, TTI can reduce the consumer exposure to altered or hazardous foods. PMID:20074826
NASA Technical Reports Server (NTRS)
Jothiprasad, Giridhar; Mavriplis, Dimitri J.; Caughey, David A.; Bushnell, Dennis M. (Technical Monitor)
2002-01-01
The efficiency gains obtained using higher-order implicit Runge-Kutta schemes as compared with the second-order accurate backward difference schemes for the unsteady Navier-Stokes equations are investigated. Three different algorithms for solving the nonlinear system of equations arising at each timestep are presented. The first algorithm (NMG) is a pseudo-time-stepping scheme which employs a non-linear full approximation storage (FAS) agglomeration multigrid method to accelerate convergence. The other two algorithms are based on Inexact Newton's methods. The linear system arising at each Newton step is solved using iterative/Krylov techniques and left preconditioning is used to accelerate convergence of the linear solvers. One of the methods (LMG) uses Richardson's iterative scheme for solving the linear system at each Newton step while the other (PGMRES) uses the Generalized Minimal Residual method. Results demonstrating the relative superiority of these Newton's methods based schemes are presented. Efficiency gains as high as 10 are obtained by combining the higher-order time integration schemes with the more efficient nonlinear solvers.
Wachs, Theodore D.; Georgieff, Michael; Cusick, Sarah; McEwen, Bruce
2014-01-01
A central issue when designing multi-dimensional biological and psychosocial interventions for children who are exposed to multiple developmental risks is identification of the age period(s) in which such interventions will have the strongest and longest lasting impact (sensitive periods). In this paper we review nutritional, neuroscience and psychological evidence on this issue. Nutritional evidence is used to identify nutrient sensitive periods of age-linked dimensions of brain development, with specific reference to iron deficiency. Neuroscience evidence is used to assess the importance of timing of exposures to environmental stressors for maintaining neural, neuroendocrine and immune systems integrity. Psychological evidence illustrates the sensitivity of cognitive and social-emotional development to contextual risk and protective influences encountered at different ages. Evidence reviewed documents that the early years of life are a sensitive period where biological or psychosocial interventions or exposure to risk or protective contextual influences can produce unique long-term influences upon human brain, neuroendocrine and cognitive or psychosocial development. However, the evidence does not identify the early years as the sole sensitive time period within which to have a significant influence upon development. Choice of age(s) to initiate interventions should be based on what outcomes are targeted and what interventions are used. PMID:24354763
Massively Parallel and Scalable Implicit Time Integration Algorithms for Structural Dynamics
NASA Technical Reports Server (NTRS)
Farhat, Charbel
1997-01-01
Explicit codes are often used to simulate the nonlinear dynamics of large-scale structural systems, even for low frequency response, because the storage and CPU requirements entailed by the repeated factorizations traditionally found in implicit codes rapidly overwhelm the available computing resources. With the advent of parallel processing, this trend is accelerating because of the following additional facts: (a) explicit schemes are easier to parallelize than implicit ones, and (b) explicit schemes induce short range interprocessor communications that are relatively inexpensive, while the factorization methods used in most implicit schemes induce long range interprocessor communications that often ruin the sought-after speed-up. However, the time step restriction imposed by the Courant stability condition on all explicit schemes cannot yet be offset by the speed of the currently available parallel hardware. Therefore, it is essential to develop efficient alternatives to direct methods that are also amenable to massively parallel processing because implicit codes using unconditionally stable time-integration algorithms are computationally more efficient when simulating the low-frequency dynamics of aerospace structures.
Adaptive neuro-fuzzy inference system for real-time monitoring of integrated-constructed wetlands.
Dzakpasu, Mawuli; Scholz, Miklas; McCarthy, Valerie; Jordan, Siobhán; Sani, Abdulkadir
2015-01-01
Monitoring large-scale treatment wetlands is costly and time-consuming, but required by regulators. Some analytical results are available only after 5 days or even longer. Thus, adaptive neuro-fuzzy inference system (ANFIS) models were developed to predict the effluent concentrations of 5-day biochemical oxygen demand (BOD5) and NH4-N from a full-scale integrated constructed wetland (ICW) treating domestic wastewater. The ANFIS models were developed and validated with a 4-year data set from the ICW system. Cost-effective, quicker and easier to measure variables were selected as the possible predictors based on their goodness of correlation with the outputs. A self-organizing neural network was applied to extract the most relevant input variables from all the possible input variables. Fuzzy subtractive clustering was used to identify the architecture of the ANFIS models and to optimize fuzzy rules, overall, improving the network performance. According to the findings, ANFIS could predict the effluent quality variation quite strongly. Effluent BOD5 and NH4-N concentrations were predicted relatively accurately by other effluent water quality parameters, which can be measured within a few hours. The simulated effluent BOD5 and NH4-N concentrations well fitted the measured concentrations, which was also supported by relatively low mean squared error. Thus, ANFIS can be useful for real-time monitoring and control of ICW systems. PMID:25607665
Aprotinin extends mechanical integrity time of cell-seeded fibrin sutures.
Coffin, Spencer T; Gaudette, Glenn R
2016-09-01
Cell therapy has the potential to treat different pathologies, including myocardial infarctions (heart attacks), although cell engraftment remains elusive with most delivery methods. Biological sutures composed of fibrin have been shown to effectively deliver human mesenchymal stem cell (MSC) to infarcted hearts. However, human MSCs rapidly degrade fibrin making cell seeding and delivery time sensitive. To delay the degradation process, we propose using Aprotinin, a proteolytic enzyme inhibitor that has been shown to slow fibrinolysis. Human MSCs seeded on fibrin sutures and incubated with Aprotinin demonstrated similar cell viability, examined using a LIVE/DEAD stain, to controls. No differences in proliferation, as determined by Ki-67 presence, were observed. Human MSCs incubated in Aprotinin differentiated into adipocytes, osteocytes, and chondrocytes, confirming multipotency. The number of cells adhered to fibrin sutures increased through Aprotinin supplementation at 2, 3, and 5 day time points. Uniaxial tensile testing was used to examine the effect of Aprotinin on suture integrity. Sutures exposed to Aprotinin had higher ultimate tensile strength and modulus when compared to sutures exposed to standard growth media. Fibrin sutures incubated in Aprotinin had larger diameters and less fibrin degradation products compared to the controls, confirming decreased fibrinolysis. These data suggest that Aprotinin can reduce degradation of fibrin sutures without significant effects on MSC function, providing a novel method for extending the implantation window and increasing the number of cells delivered via fibrin sutures. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2271-2279, 2016. PMID:27101153
NASA Astrophysics Data System (ADS)
Mangiameli, M.; Mussumeci, G.
2013-01-01
A wide series of events requires immediate availability of information and field data to be provided to decision-makers. An example is the necessity of quickly transferring the information acquired from monitoring and alerting sensors or the data of the reconnaissance of damage after a disastrous event to an Emergency Operations Center. To this purpose, we developed an integrated GIS and WebGIS system to dynamically create and populate via Web a database with spatial features. In particular, this work concerns the gathering and transmission of spatial data and related information to the desktop GIS so that they can be displayed and analyzed in real time to characterize the operational scenario and to decide the rescue interventions. As basic software, we used only free and open source: QuantumGIS and Grass as Desktop GIS, Map Server with PMapper application for the Web-Gis functionality and PostGreSQL/PostGIS as Data Base Management System (DBMS). The approach has been designed, developed and successfully tested in the management of GIS-based navigation of an autonomous robot, both to map its trajectories and to assign optimal paths. This paper presents the application of our system to a simulated hydrological event that could interest the province of Catania, in Sicily. In particular, assuming that more teams draw up an inventory of the damage, we highlight the benefits of real-time transmission of the information collected from the field to headquarters.
ICESAT Laser Altimeter Pointing, Ranging and Timing Calibration from Integrated Residual Analysis
NASA Technical Reports Server (NTRS)
Luthcke, Scott B.; Rowlands, D. D.; Carabajal, C. C.; Harding, D. H.; Bufton, J. L.; Williams, T. A.
2003-01-01
On January 12, 2003 the Ice, Cloud and land Elevation Satellite (ICESat) was successfully placed into orbit. The ICESat mission carries the Geoscience Laser Altimeter System (GLAS), which has a primary measurement of short-pulse laser- ranging to the Earth s surface at 1064nm wavelength at a rate of 40 pulses per second. The instrument has collected precise elevation measurements of the ice sheets, sea ice roughness and thickness, ocean and land surface elevations and surface reflectivity. The accurate geolocation of GLAS s surface returns, the spots from which the laser energy reflects on the Earth s surface, is a critical issue in the scientific application of these data. Pointing, ranging, timing and orbit errors must be compensated to accurately geolocate the laser altimeter surface returns. Towards this end, the laser range observations can be fully exploited in an integrated residual analysis to accurately calibrate these geolocation/instrument parameters. ICESat laser altimeter data have been simultaneously processed as direct altimetry from ocean sweeps along with dynamic crossovers in order to calibrate pointing, ranging and timing. The calibration methodology and current calibration results are discussed along with future efforts.
NASA Astrophysics Data System (ADS)
Butkiewicz, Michael; Butkiewicz, Thomas; Ribarsky, William; Chang, Remco
2009-05-01
Aviation disaster prevention has always been of interest to homeland security, especially after the recent use of aircrafts as weapons by terrorists. With better understanding of the deficiency of different types of aircraft and their corresponding effects on the craft's safety, better maintenance and response plans can be devised to prevent disasters from occurring. In this paper, we present a visual analytical technique to examine the Federal Aviation Agency's Accident/Incident Database, which contains more than 90,000 incidents across 53 dimensions over the last 30 years, for identifying trends of relationships between dimensions over time. Our technique is based on the integration of the ThemeRiver technique directly within a parallel coordinates framework, and simultaneously presents both a "forward flow view" and a "backward flow view" between each dimension. The forward flow view shows the trends over time of each of the elements-of-interest in the first dimension, while the backward flow view illustrates how the elements in the second dimension contribute to the overall trends seen in the first dimension. Through the use of our technique, we were able to identify characteristics of aircrafts and suggest plausible explanations to their common failures.
Photothermal damage is correlated to the delivery rate of time-integrated temperature
NASA Astrophysics Data System (ADS)
Denton, Michael L.; Noojin, Gary D.; Gamboa, B. Giovanna; Ahmed, Elharith M.; Rockwell, Benjamin A.
2016-03-01
Photothermal damage rate processes in biological tissues are usually characterized by a kinetics approach. This stems from experimental data that show how the transformation of a specified biological property of cells or biomolecule (plating efficiency for viability, change in birefringence, tensile strength, etc.) is dependent upon both time and temperature. However, kinetic methods require determination of kinetic rate constants and knowledge of substrate or product concentrations during the reaction. To better understand photothermal damage processes we have identified temperature histories of cultured retinal cells receiving minimum lethal thermal doses for a variety of laser and culture parameters. These "threshold" temperature histories are of interest because they inherently contain information regarding the fundamental thermal dose requirements for damage in individual cells. We introduce the notion of time-integrated temperature (Tint) as an accumulated thermal dose (ATD) with units of °C s. Damaging photothermal exposure raises the rate of ATD accumulation from that of the ambient (e.g. 37 °C) to one that correlates with cell death (e.g. 52 °C). The degree of rapid increase in ATD (ΔATD) during photothermal exposure depends strongly on the laser exposure duration and the ambient temperature.
A Vertically Integrated CMOS Microsystem for Time-Resolved Fluorescence Analysis.
Rae, Bruce R; Jingbin Yang; McKendry, Jonathan; Zheng Gong; Renshaw, David; Girkin, John M; Erdan Gu; Dawson, Martin D; Henderson, R K
2010-12-01
We describe a two-chip micro-scale time-resolved fluorescence analyzer integrating excitation, detection, and filtering. A new 8×8 array of drivers realized in standard low-voltage 0.35-μm complementary metal-oxide semiconductor is bump-bonded to AlInGaN blue micro-pixellated light-emitting diodes (micro-LEDs). The array is capable of producing sample excitation pulses with a width of 777 ps (FWHM), enabling short lifetime fluorophores to be investigated. The fluorescence emission is detected by a second, vertically-opposed 16 × 4 array of single-photon avalanche diodes (SPADs) fabricated in 0.35-μm high-voltage CMOS technology with in-pixel time-gated photon counting circuitry. Captured chip data are transferred to a PC for further processing, including histogramming, lifetime extraction, calibration and background/noise compensation. This constitutes the smallest reported solid-state microsystem for fluorescence decay analysis, replacing lasers, photomultiplier tubes, bulk optics, and discrete electronics. The system is demonstrated with measurements of fluorescent colloidal quantum dot and Rhodamine samples. PMID:23853381
Active ultrasonic joint integrity adjudication for real-time structural health monitoring
NASA Astrophysics Data System (ADS)
Clayton, Erik H.; Kennel, Matthew B.; Fasel, Timothy R.; Todd, Michael D.; Stabb, Mark C.; Arritt, Brandon J.
2008-03-01
The Operationally Responsive Space (ORS) strategy hinges, in part, on realizing technologies which can facilitate the rapid deployment of satellites. Presently, preflight qualification testing and vehicle integration processes are time consumptive and pose as two significant hurdles which must be overcome to effectively enhance US space asset deployment responsiveness. There is a growing demand for innovative embedded Structural Health Monitoring (SHM) technologies which can be seamlessly incorporated onto payload hardware and function in parallel with satellite construction to mitigate lengthy preflight checkout procedures. In this effort our work is focused on the development of a joint connectivity monitoring algorithm which can detect, locate, and assess preload in bolted joint assemblies. Our technology leverages inexpensive, lightweight, flexible thin-film macro-fiber composite (MFC) sensor/actuators with a novel online, data-driven signal processing algorithm. This algorithm inherently relies upon Chaotic Guided Ultrasonic Waves (CGUW) and a novel cross-prediction error classification technique. The efficacy of the monitoring algorithm is evaluated through a series of numerical simulations and experimentally in two test configurations. We conclude with a discussion surrounding further development of this approach into a commercial product as a real-time flight readiness indicator.
Histotripsy Cardiac Therapy System Integrated with Real-time Motion Correction
Miller, Ryan M.; Kim, Yohan; Lin, Kuang-Wei; Cain, Charles A.; Owens, Gabe E.; Xu, Zhen
2013-01-01
Histotripsy has shown promise in non-invasive cardiac therapy for neonatal and fetal applications. However for cardiac applications in general, and especially in the adult heart, cardiac and respiratory motion may affect the treatment accuracy and efficacy. This paper presents a histotripsy-mediated cardiac therapy system integrated with a fast motion-tracking algorithm and treatment monitoring using ultrasound imaging. Motion tracking is performed by diamond search block matching in real-time ultrasound images using a reference image of the moving target, refined by Kalman filtering. As proof of feasibility, this algorithm was configured to track 2D target motion and then electronically adjust the focus of a 1 MHz annular therapy array to correct for axial motion. This integrated motion tracking system is capable of sub-mm accuracy for displacements of 0–15 mm and velocities of 0–80 mm/s with a maximum error of less than 3 mm. Tissue phantom tests showed treatment efficiency and lesion size using motion tracking over displacements of 0–15 mm and velocities of 0–42 mm/s are comparable to those produced when treating stationary targets. In vivo validation was conducted in an open chest canine model, where the system provided 24 minutes of motion corrected histotripsy therapy in the live beating heart, generating a targeted lesion on the atrial septum. Based on this proof of feasibility and the natural extension of these techniques to three-dimensions, we anticipate a full motion correction system would be feasible and beneficial for non-invasive cardiac therapy. PMID:24063958
Designing Adaptive Low-Dissipative High Order Schemes for Long-Time Integrations. Chapter 1
NASA Technical Reports Server (NTRS)
Yee, Helen C.; Sjoegreen, B.; Mansour, Nagi N. (Technical Monitor)
2001-01-01
A general framework for the design of adaptive low-dissipative high order schemes is presented. It encompasses a rather complete treatment of the numerical approach based on four integrated design criteria: (1) For stability considerations, condition the governing equations before the application of the appropriate numerical scheme whenever it is possible; (2) For consistency, compatible schemes that possess stability properties, including physical and numerical boundary condition treatments, similar to those of the discrete analogue of the continuum are preferred; (3) For the minimization of numerical dissipation contamination, efficient and adaptive numerical dissipation control to further improve nonlinear stability and accuracy should be used; and (4) For practical considerations, the numerical approach should be efficient and applicable to general geometries, and an efficient and reliable dynamic grid adaptation should be used if necessary. These design criteria are, in general, very useful to a wide spectrum of flow simulations. However, the demand on the overall numerical approach for nonlinear stability and accuracy is much more stringent for long-time integration of complex multiscale viscous shock/shear/turbulence/acoustics interactions and numerical combustion. Robust classical numerical methods for less complex flow physics are not suitable or practical for such applications. The present approach is designed expressly to address such flow problems, especially unsteady flows. The minimization of employing very fine grids to overcome the production of spurious numerical solutions and/or instability due to under-resolved grids is also sought. The incremental studies to illustrate the performance of the approach are summarized. Extensive testing and full implementation of the approach is forthcoming. The results shown so far are very encouraging.
Sharp, P E
1999-01-01
Cells in several portions of the hippocampal formation show location-related firing, so that the momentary rate of each cell signals the spatial location of a freely moving rat. Insight into how these signals are generated, and how they travel around the hippocampal circuitry, can be gained by examination of the exact timing of the locational signal. Here, this was investigated for both hippocampal and subicular cells. For this, several aspects of the spatial firing pattern of each cell were examined over a series of time shifts, in which spikes were paired with locations occupied by the animal in either the immediate past, present, or future. Results showed that subicular cells appear to anticipate future locations by approximately 50 to 70 msec, on average. In contrast, hippocampal cells were best correlated with positions about 30 to 40 msec in the future. However, this timing, for hippocampal cells only, was related to the average session running speed, so that the cells were correlated with future locations at slow speeds, but lagged behind (were correlated with past locations) at high speeds. These data support the idea that both subicular and hippocampal cells use a path integration mechanism to generate their spatial signal (since both can anticipate future location). For the hippocampal cells the mechanism does not, apparently, take into account speed information, however. Also, the data suggest that the subicular signal cannot be the result of simple transmission of spatial information from the hippocampus to the subiculum, since this would predict that the subicular signal should correlate with later positions than the hippocampal signal. PMID:10226776
Gans, Donald; Sheykholeslami, Kianoush; Peterson, Diana Coomes; Wenstrup, Jeffrey
2009-07-01
This report examines temporal features of facilitation and suppression that underlie spectrally integrative responses to complex vocal signals. Auditory responses were recorded from 160 neurons in the inferior colliculus (IC) of awake mustached bats. Sixty-two neurons showed combination-sensitive facilitation: responses to best frequency (BF) signals were facilitated by well-timed signals at least an octave lower in frequency, in the range 16-31 kHz. Temporal features and strength of facilitation were generally unaffected by changes in duration of facilitating signals from 4 to 31 ms. Changes in stimulus rise time from 0.5 to 5.0 ms had little effect on facilitatory strength. These results suggest that low frequency facilitating inputs to high BF neurons have phasic-on temporal patterns and are responsive to stimulus rise times over the tested range. We also recorded from 98 neurons showing low-frequency (11-32 kHz) suppression of higher BF responses. Effects of changing duration were related to the frequency of suppressive signals. Signals<23 kHz usually evoked suppression sustained throughout signal duration. This and other features of such suppression are consistent with a cochlear origin that results in masking of responses to higher, near-BF signal frequencies. Signals in the 23- to 30-kHz range-frequencies in the first sonar harmonic-generally evoked phasic suppression of BF responses. This may result from neural inhibitory interactions within and below IC. In many neurons, we observed two or more forms of the spectral interactions described here. Thus IC neurons display temporally and spectrally complex responses to sound that result from multiple spectral interactions at different levels of the ascending auditory pathway. PMID:19403742
New insights into the functions of intersectin-1s
Predescu, Sanda; Bardita, Cristina; Predescu, Dan
2015-01-01
Intersectin-1s (ITSN) is a ubiquitously expressed multifunctional protein known as a scaffold and regulator of the general endocytic machinery as well as a critical integrator of cellular signaling pathways. We showed recently that ITSN deficiency triggers a transforming growth factor β (TGFβ)/Alk5 signaling switch, from the canonical Smad 2/3 to the Erk1/2 MAPK pathway; moreover, endocytic impairment induced by ITSN deficiency enhances Alk5 ubiquitination and degradation and elicits TGFβ-paracrine effects mediated by circulating microparticles, leading to endothelial cell survival and increased proliferation. The studies expand our understanding of how ITSN facilitates cross-regulation of signaling pathways and provide insights into the involvement of ITSN deficiency in human disease. PMID:26479042
New insights into the functions of intersectin-1s.
Predescu, Sanda; Bardita, Cristina; Predescu, Dan
2015-01-01
Intersectin-1s (ITSN) is a ubiquitously expressed multifunctional protein known as a scaffold and regulator of the general endocytic machinery as well as a critical integrator of cellular signaling pathways. We showed recently that ITSN deficiency triggers a transforming growth factor β (TGFβ)/Alk5 signaling switch, from the canonical Smad 2/3 to the Erk1/2 MAPK pathway; moreover, endocytic impairment induced by ITSN deficiency enhances Alk5 ubiquitination and degradation and elicits TGFβ-paracrine effects mediated by circulating microparticles, leading to endothelial cell survival and increased proliferation. The studies expand our understanding of how ITSN facilitates cross-regulation of signaling pathways and provide insights into the involvement of ITSN deficiency in human disease. PMID:26479042
Closed Newton-Cotes Trigonometrically-Fitted Formulae for Long-Time Integration of Orbital Problems
NASA Astrophysics Data System (ADS)
Simos, T. E.
2006-10-01
The connection between closed Newton-Cotes, trigonometrically-fitted differential methods and symplectic integrators is investigated in this paper. It is known from the literature that several one step symplectic integrators have been obtained based on symplectic geometry. However, the investigation of multistep symplectic integrators is very poor. Zhu et al.(1996) presented the well known open Newton-Cotes differential methods as multilayer symplectic integrators. Also, Chiou & Wu (1997) investigated the construction of multistep symplectic integrators based on the open Newton-Cotes integration methods. In this paper we investigate the closed Newton-Cotes formulae and we write them as symplectic multilayer structures. After this we construct trigonometrically-fitted symplectic methods which are based on the closed Newton-Cotes formulae. We apply the symplectic schemes in order to solve Hamilton's equations of motion which are linear in position and momentum. We observe that the Hamiltonian energy of the system remains almost constant as integration procceeds.
Model Integration for Real-Time Flood Forecasting Inundation Mapping for Nashville Tributaries
NASA Astrophysics Data System (ADS)
Charley, W.; Moran, B.; LaRosa, J.
2012-12-01
In May of 2010, between 14 and 19 inches of rain fell on the Nashville metro area in two days, quickly overwhelming tributaries to the Cumberland River and causing wide-spread, serious flooding. Tractor-trailers and houses were seen floating down Mill Creek, a primary tributary in the south eastern area of Nashville. Twenty-six people died and over 2 billion dollars in damage occurred as a result of the flood. Since that time, several other significant rainfall events have occurred in the area. Emergency responders were unable to deliver aid or preventive measures to areas under threat of flooding (or under water) in time to reduce damages because they could not identify those areas far enough in advance of the floods. Nashville Metro Water, the National Weather Service, the US Geological Survey and the US Army Corps of Engineers established a joint venture to seek ways to better forecast short-term flood events in the region. One component of this effort was a pilot project to compute and display real time inundation maps for Mill Creek, a 108 square-mile basin to the south east of Nashville. HEC-RTS (Real-Time Simulation) was used to assimilate and integrate the hydrologic model HEC-HMS with the hydraulics model HEC-RAS and the inundation mapping program HEC-RAS Mapper. The USGS, along with the other agencies, installed additional precipitation and flow/stage gages in the area. Measurements are recorded every 5-30 minutes and are posted on the USGS NWIS database, which are downloaded by HEC-RTS. Using this data in combination with QPFs (Quantitative Precipitation Forecasts) from the NWS, HEC-RTS applies HEC-HMS and HEC-RAS to estimate current and forecast stage hydrographs. The peak stages are read by HEC-RAS Mapper to compute inundation depths for 6 by 6 foot grid cells. HEC-RTS displays the inundation on a high resolution MrSid aerial photo, along with subbasin boundary, street and various other layers. When a user zooms in and "mouses" over a cell, the
Rain rate modeling of 1-min from various integration times in South Korea.
Shrestha, Sujan; Park, Jung-Jin; Choi, Dong-You
2016-01-01
Rain plays a major impairment factor for propagation of electromagnetic waves in atmosphere for systems operating at frequencies above 10 GHz. Several effects are noted such as depolarization, scintillation, interference due to scattering and extra attenuation which seems to increase with frequency. To mitigate its effect in satellite communication, knowledge of local rainfall statistics is necessary which act as milestone for design of radio link. Rain attenuation is best visualize by the 1-min rainfall rate statistic but the measurement of this rain rate distribution is rare on a worldwide basis and observation of rain rate are done with longer integration times typically 30 min or more. In this paper, efforts have been made to develop model that can convert rain rate complementary cumulative distribution function to shorter integration times. The average relative error margin of about 5, 14, 43, 71 and 115 % are noted for 5 to 1-, 10 to 1-, 20 to 1, 30 to 1- and 60 to 1-min respectively from ITU-R P.837-6 method which have been analyzed in further section of this article. The empirical natures of conversion methods as such Segal method, Burgueno's method, Chebil and Rahman method and Logarithmic model are studied along with the proposed new model that seems to be applicable in derivation of 1-min rain rate of the South Korea rain rate statistics. International Telecommunication Union-Radio communication Sector (ITU-R) has developed a recommendation ITU-R P.837-6 that enables the user to estimate the local 1-min rainfall rate statistical distribution which is compared with calculated 1-min rain rate distribution from experimental 1-min rainfall accumulation. Unfortunately, ITU-R P.837-6 estimated 1-min values show greater error percentages. In order to get better approximation of local 1-min rain rate estimation, a novel method is proposed and it's efficiency have been compared with rainfall rate statistics obtained from nine different locations in the South
Spiesberger, John L
2013-02-01
The hypothesis tested is that internal gravity waves limit the coherent integration time of sound at 1346 km in the Pacific ocean at 133 Hz and a pulse resolution of 0.06 s. Six months of continuous transmissions at about 18 min intervals are examined. The source and receiver are mounted on the bottom of the ocean with timing governed by atomic clocks. Measured variability is only due to fluctuations in the ocean. A model for the propagation of sound through fluctuating internal waves is run without any tuning with data. Excellent resemblance is found between the model and data's probability distributions of integration time up to five hours. PMID:23363091
NASA Technical Reports Server (NTRS)
Joseph, Rose M.; Goorjian, Peter M.; Taflove, Allen
1993-01-01
We present what are to our knowledge first-time calculations from vector nonlinear Maxwell's equations of femtosecond soliton propagation and scattering, including carrier waves, in two-dimensional dielectric waveguides. The time integration efficiently implements linear and nonlinear convolutions for the electric polarization, and the nonlinear convolution accounts for two quantum effects, the Kerr and Raman interactions. By retaining the optical carrier, the new method solves for fundamental quantities - optical electric and magnetic fields in space and time - rather than a nonphysical envelope function. It has the potential to provide an unprecedented two- and three-dimensional modeling capability for millimeter-scale integrated-optical circuits with submicrometer engineered inhomogeneities.
Fine, Dana S.; Sawin, Stephen
2014-06-15
Following Feynman's prescription for constructing a path integral representation of the propagator of a quantum theory, a short-time approximation to the propagator for imaginary-time, N = 1 supersymmetric quantum mechanics on a compact, even-dimensional Riemannian manifold is constructed. The path integral is interpreted as the limit of products, determined by a partition of a finite time interval, of this approximate propagator. The limit under refinements of the partition is shown to converge uniformly to the heat kernel for the Laplace-de Rham operator on forms. A version of the steepest descent approximation to the path integral is obtained, and shown to give the expected short-time behavior of the supertrace of the heat kernel.
Islam, Mohammad K.; Norrlinger, Bernhard D.; Smale, Jason R.; Heaton, Robert K.; Galbraith, Duncan; Fan, Cary; Jaffray, David A.
2009-12-15
Purpose: To develop an independent and on-line beam monitoring system, which can validate the accuracy of segment-by-segment energy fluence delivery for each treatment field. The system is also intended to be utilized for pretreatment dosimetric quality assurance of intensity modulated radiation therapy (IMRT), on-line image-guided adaptive radiation therapy, and volumetric modulated arc therapy. Methods: The system, referred to as the integral quality monitor (IQM), utilizes an area integrating energy fluence monitoring sensor (AIMS) positioned between the final beam shaping device [i.e., multileaf collimator (MLC)] and the patient. The prototype AIMS consists of a novel spatially sensitive large area ionization chamber with a gradient along the direction of the MLC motion. The signal from the AIMS provides a simple output for each beam segment, which is compared in real time to the expected value. The prototype ionization chamber, with a physical area of 22x22 cm{sup 2}, has been constructed out of aluminum with the electrode separations varying linearly from 2 to 20 mm. A calculation method has been developed to predict AIMS signals based on an elementwise integration technique, which takes into account various predetermined factors, including the spatial response function of the chamber, MLC characteristics, beam transmission through the secondary jaws, and field size factors. The influence of the ionization chamber on the beam has been evaluated in terms of transmission, surface dose, beam profiles, and depth dose. The sensitivity of the system was tested by introducing small deviations in leaf positions. A small set of IMRT fields for prostate and head and neck plans was used to evaluate the system. The ionization chamber and the data acquisition software systems were interfaced to two different types of linear accelerators: Elekta Synergy and Varian iX. Results: For a 10x10 cm{sup 2} field, the chamber attenuates the beam intensity by 7% and 5% for 6 and 18
NASA Astrophysics Data System (ADS)
French, H. K.; Van Der Zee, S. E.; Wehrer, M.; Godio, A.; Pedersen, L. B.; Tsocano, G.
2013-12-01
measurements indicate where the remaining crude oil can be found. Water samples from multilevel samplers reveal crude oil present in emulsion in the zone of groundwater fluctuations, highlighting the importance of colloidal transport. Modelling of multiphase flow of the fluctuating groundwater level explains the lack of horizontal displacement of the plume in the area. Geochemistry of the groundwater clearly indicates degradation of hydrocarbons under iron- and sulphate reducing conditions, but changes were too slow to be mapped by time-lapse geophysical measurements during the project period. MODFLOW was used to simulate the regional groundwater flow and transport in the area. Highlights of the results from both test sites will be presented as an integrated overview. Snow removal at Oslo airport
Precision frequency measurement of 1S0-3P1 intercombination lines of Sr isotopes
NASA Astrophysics Data System (ADS)
Liu, Hui; Gao, Feng; Ye-Bing, Wang; Xiao, Tian; Jie, Ren; Ben-Quan, Lu; Qin-Fang, Xu; Yu-Lin, Xie; Hong, Chang
2015-01-01
We report on frequency measurement of the intercombination (5s2)1S0-(5s5p)3P1 transition of the four natural isotopes of strontium, including 88Sr (82.58%), 87Sr (7.0%), 86Sr (9.86%), and 84Sr (0.56%). A narrow-linewidth laser that is locked to an ultra-low expansion (ULE) optical cavity with a finesse of 12000 is evaluated at a linewidth of 200 Hz with a fractional frequency drift of 2.8×10-13 at an integration time of 1 s. The fluorescence collector and detector are specially designed, based on a thermal atomic beam. Using a double-pass acousto-optic modulator (AOM) combined with a fiber and laser power stabilization configuration to detune the laser frequency enables high signal-to-noise ratios and precision saturated spectra to be obtained for the six transition lines, which allows us to determine the transition frequency precisely. The optical frequency is measured using an optical frequency synthesizer referenced to an H maser. Both the statistical values and the final values, including the corrections and uncertainties, are derived for a comparison with the values given in other works. Project supported by the National Natural Science Foundation of China (Grant No. 61127901) and the Key Project of the Chinese Academy of Sciences (Grant No. KJZD-EW-W02).
Cimorelli, A.J.; Stahl, C.H.; Chow, A.H.; Fernandez, C.
1999-07-01
A critical evaluation of the many environmental issues facing EPA Region 3 has established five major priorities: (1) ozone pollution (and its precursors); (2) impacts of acidification (acid deposition and acid mine drainage); (3) eutrophication of the Chesapeake Bay from atmospheric nitrogen deposition; (4) Cities/Urban Environment (ozone, particulate matter (PM), air toxics are some of the air components); and (5) Climate Change. Recognizing the complex nature of the systems controlling these issues, Region III's Air Protection Division (APD) is developing a decision support tool, i.e., the Decision Consequence Model (DCM), that will integrate and automate the analysis of environmental impacts in a manner that allows them to holistically address these regional priorities. Using this tool the authors intend to consider the interdependency of pollutants and their environmental impacts in order to support real-time decision making. The purpose of this paper is to outline the basic concept of the DCM and to present an example set of environmental indicators to illustrate how the DCM will be used to evaluate environmental impacts. The authors will discuss their process of indicator development, and present an example suite of indicators to provide a concrete example of the concepts presented above and, to illustrate the utility of the DCM to simultaneously evaluate multiple effects of a single pollutant. They will discuss the type of indicators chosen for this example as well as the general criteria the DCM indicators must satisfy. The framework that was developed to construct the indicators is discussed and used to calculate the example indicators. The yearly magnitudes of these example indicators are calculated for various multi-year periods to show their behavior over time.
Wang, Zhisong; Logothetis, Nikos K; Liang, Hualou
2009-12-01
The question of how perception arises from neuronal activity in the visual cortex is of fundamental importance to many issues in cognitive neuroscience. To address this question, we adopt a unique experimental paradigm in which bistable stimuli, namely structure from motion (SFM), are employed to dissociate the visual input from perception while monitoring cortical neural activity. In this paper, we analyze the dynamic responses of the multiunit activity, simultaneously collected from multiple channels in the middle temporal visual cortex of awake behaving macaque monkeys, for decoding the bistable percepts of SFM in a response-time (RT) perceptual discrimination task. Our goal is to understand how the perceptual discriminative information of neuronal population activity evolves and accumulates over time to mediate behaviors. Here, we used a discriminative classifier called the logistic regression and contrasted it with two generative classifiers, namely the quadratic discriminant analysis (QDA) and linear discriminant analysis (LDA), to achieve the spatiotemporal integration of neural activity and dynamically decode the perceptual reports on a single-trial basis. We found that the logistic regression outperforms both QDA and LDA in terms of decoding accuracy for both single-channel and multichannel decoding of bistable percepts. Subsequent analysis of the temporal profile of neural population decoding in relation to RT revealed that the amplitude and latency of the decoding accuracy are highly correlated with the RT, thus indicating that the monkeys respond faster when the decoding accuracy is higher and has shorter latency. These findings suggest that enhanced neuronal discrimination ability and shortened neuronal discrimination latency may impact monkeys' behaviors. PMID:19635689
Integrated Interventional Devices For Real Time 3D Ultrasound Imaging and Therapy
NASA Astrophysics Data System (ADS)
Smith, Stephen W.; Lee, Warren; Gentry, Kenneth L.; Pua, Eric C.; Light, Edward D.
2006-05-01
Two recent advances have expanded the potential of medical ultrasound: the introduction of real-time 3-D ultrasound imaging with catheter, transesophageal and laparoscopic probes and the development of interventional ultrasound therapeutic systems for focused ultrasound surgery, ablation and ultrasound enhanced drug delivery. This work describes devices combining both technologies. A series of transducer probes have been designed, fabricated and tested including: 1) a 12 French side scanning catheter incorporating a 64 element matrix array for imaging at 5MHz and a piston ablation transducer operating at 10 MHz. 2) a 14 Fr forward-scanning catheter integrating a 112 element 2-D array for imaging at 5 MHz encircled by an ablation annulus operating at 10 MHz. Finite element modeling was then used to simulate catheter annular and linear phased array transducers for ablation. 3) Linear phased array transducers were built to confirm the finite element analysis at 4 and 8 MHz including a mechanically focused 86 element 9 MHz array which transmits an ISPTA of 29.3 W/cm2 and creates a lesion in 2 minutes. 4) 2-D arrays of 504 channels operating at 5 MHz have been developed for transesophageal and laparascopic 3D imaging as well as therapeutic heating. All the devices image the heart anatomy including atria, valves, septa and en face views of the pulmonary veins.
A mixed time integration method for large scale acoustic fluid-structure interaction
Christon, M.A.; Wineman, S.J.; Goudreau, G.L.; Foch, J.D.
1994-07-18
The transient, coupled, interaction of sound with structures is a process in which an acoustic fluid surrounding an elastic body contributes to the effective inertia and elasticity of the body. Conversely, the presence of an elastic body in an acoustic medium influences the behavior of propagating disturbances. This paper details the application of a mixed explicit-implicit time integration algorithm to the fully coupled acoustic fluidstructure interaction problem. Based upon a dispersion analysis of the semi-discrete wave equation a second-order, explicit scheme for solving the wave equation is developed. The combination of a highly vectorized, explicit, acoustic fluid solver with an implicit structural code for linear elastodynamics has resulted in a simulation tool, PING, for acoustic fluid-structure interaction. PING`s execution rates range from 1{mu}s/Element/{delta}t for rigid scattering to 10{mu}s/Element/{delta}t for fully coupled problems. Several examples of PING`s application to 3-D problems serve in part to validate the code, and also to demonstrate the capability to treat complex geometry, acoustic fluid-structure problems which require high resolution meshes.
Zhao, Jinkui Hamilton, William A.; Robertson, J. L.; Crow, Lowell; Lee, Sung-Woo; Kang, Yoon W.
2015-09-14
The analysis of neutron diffraction experiments often assumes that neutrons are elastically scattered from the sample. However, there is growing evidence that a significant fraction of the detected neutrons is in fact inelastically scattered, especially from soft materials and aqueous samples. Ignoring these inelastic contributions gives rise to inaccurate experimental results. To date, there has been no simple method with broad applicability for inelastic signal separation in neutron diffraction experiments. Here, we present a simple and robust method that we believe could be suited for this purpose. We use two radio frequency resonant spin flippers integrated with a Larmor precession field to modulate the neutron intensity and to encode the inelastic scattering information into the neutron data. All three components contribute to the spin encoding. The Larmor field serves several additional purposes. Its usage facilitates neutron time-focusing, eliminates the need for stringent magnetic shielding, and allows for compact setups. The scheme is robust, simple, and flexible. We believe that, with further improvements, it has the potential of adding inelastic signal discrimination capabilities to many existing diffraction instruments in the future.
NASA Astrophysics Data System (ADS)
Musafere, F.; Sadhu, A.; Liu, K.
2016-01-01
In the last few decades, structural health monitoring (SHM) has been an indispensable subject in the field of vibration engineering. With the aid of modern sensing technology, SHM has garnered significant attention towards diagnosis and risk management of large-scale civil structures and mechanical systems. In SHM, system identification is one of major building blocks through which unknown system parameters are extracted from vibration data of the structures. Such system information is then utilized to detect the damage instant, and its severity to rehabilitate and prolong the existing health of the structures. In recent years, blind source separation (BSS) algorithm has become one of the newly emerging advanced signal processing techniques for output-only system identification of civil structures. In this paper, a novel damage detection technique is proposed by integrating BSS with the time-varying auto-regressive modeling to identify the instant and severity of damage. The proposed method is validated using a suite of numerical studies and experimental models followed by a full-scale structure.
Focal plane resolution and overlapped array time delay and integrate imaging
NASA Astrophysics Data System (ADS)
Grycewicz, Thomas J.; Cota, Stephen A.; Lomheim, Terrence S.; Kalman, Linda S.
2010-06-01
In this paper we model sub-pixel image registration for a generic earth-observing satellite system with a focal plane using two offset time delay and integrate (TDI) arrays in the focal plane to improve the achievable ground resolution over the resolution achievable with a single array. The modeling process starts with a high-resolution image as ground truth. The Parameterized Image Chain Analysis & Simulation Software (PICASSO) modeling tool is used to degrade the images to match the optical transfer function, sampling, and noise characteristics of the target system. The model outputs a pair of images with a separation close to the nominal half-pixel separation between the overlapped arrays. A registration estimation algorithm is used to measure the offset for image reconstruction. The two images are aligned and summed on a grid with twice the capture resolution. We compare the resolution in images between the inputs before overlap, the reconstructed image, and a simulation for the image which would have been captured on a focal plane with twice the resolution. We find the performance to always be better than the lower resolution baseline, and to approach the performance of the high-resolution array in the ideal case. We show that the overlapped array imager significantly outperforms both the conventional high- and low-resolution imagers in conditions with high image smear.
NASA Astrophysics Data System (ADS)
Zhao, Jinkui; Hamilton, William A.; Lee, Sung-Woo; Robertson, J. L.; Crow, Lowell; Kang, Yoon W.
2015-09-01
The analysis of neutron diffraction experiments often assumes that neutrons are elastically scattered from the sample. However, there is growing evidence that a significant fraction of the detected neutrons is in fact inelastically scattered, especially from soft materials and aqueous samples. Ignoring these inelastic contributions gives rise to inaccurate experimental results. To date, there has been no simple method with broad applicability for inelastic signal separation in neutron diffraction experiments. Here, we present a simple and robust method that we believe could be suited for this purpose. We use two radio frequency resonant spin flippers integrated with a Larmor precession field to modulate the neutron intensity and to encode the inelastic scattering information into the neutron data. All three components contribute to the spin encoding. The Larmor field serves several additional purposes. Its usage facilitates neutron time-focusing, eliminates the need for stringent magnetic shielding, and allows for compact setups. The scheme is robust, simple, and flexible. We believe that, with further improvements, it has the potential of adding inelastic signal discrimination capabilities to many existing diffraction instruments in the future.
NASA Astrophysics Data System (ADS)
Viehland, Christian; Keller, Brenton; Carrasco-Zevallos, Oscar; Cunefare, David; Shen, Liangbo; Toth, Cynthia; Farsiu, Sina; Izatt, Joseph A.
2016-03-01
Optical coherence tomography (OCT) allows for micron scale imaging of the human retina and cornea. Current generation research and commercial intrasurgical OCT prototypes are limited to live B-scan imaging. Our group has developed an intraoperative microscope integrated OCT system capable of live 4D imaging. With a heads up display (HUD) 4D imaging allows for dynamic intrasurgical visualization of tool tissue interaction and surgical maneuvers. Currently our system relies on operator based manual tracking to correct for patient motion and motion caused by the surgeon, to track the surgical tool, and to display the correct B-scan to display on the HUD. Even when tracking only bulk motion, the operator sometimes lags behind and the surgical region of interest can drift out of the OCT field of view. To facilitate imaging we report on the development of a fast volume based tool segmentation algorithm. The algorithm is based on a previously reported volume rendering algorithm and can identify both the tool and retinal surface. The algorithm requires 45 ms per volume for segmentation and can be used to actively place the B-scan across the tool tissue interface. Alternatively, real-time tool segmentation can be used to allow the surgeon to use the surgical tool as an interactive B-scan pointer.
Goswami, Anjali; Binder, Wendy J.; Meachen, Julie; O’Keefe, F. Robin
2015-01-01
Variation is the raw material for natural selection, but the factors shaping variation are still poorly understood. Genetic and developmental interactions can direct variation, but there has been little synthesis of these effects with the extrinsic factors that can shape biodiversity over large scales. The study of phenotypic integration and modularity has the capacity to unify these aspects of evolutionary study by estimating genetic and developmental interactions through the quantitative analysis of morphology, allowing for combined assessment of intrinsic and extrinsic effects. Data from the fossil record in particular are central to our understanding of phenotypic integration and modularity because they provide the only information on deep-time developmental and evolutionary dynamics, including trends in trait relationships and their role in shaping organismal diversity. Here, we demonstrate the important perspective on phenotypic integration provided by the fossil record with a study of Smilodon fatalis (saber-toothed cats) and Canis dirus (dire wolves). We quantified temporal trends in size, variance, phenotypic integration, and direct developmental integration (fluctuating asymmetry) through 27,000 y of Late Pleistocene climate change. Both S. fatalis and C. dirus showed a gradual decrease in magnitude of phenotypic integration and an increase in variance and the correlation between fluctuating asymmetry and overall integration through time, suggesting that developmental integration mediated morphological response to environmental change in the later populations of these species. These results are consistent with experimental studies and represent, to our knowledge, the first deep-time validation of the importance of developmental integration in stabilizing morphological evolution through periods of environmental change. PMID:25901310
Tanizaki, Yuya; Koike, Takayuki
2014-12-15
Picard–Lefschetz theory is applied to path integrals of quantum mechanics, in order to compute real-time dynamics directly. After discussing basic properties of real-time path integrals on Lefschetz thimbles, we demonstrate its computational method in a concrete way by solving three simple examples of quantum mechanics. It is applied to quantum mechanics of a double-well potential, and quantum tunneling is discussed. We identify all of the complex saddle points of the classical action, and their properties are discussed in detail. However a big theoretical difficulty turns out to appear in rewriting the original path integral into a sum of path integrals on Lefschetz thimbles. We discuss generality of that problem and mention its importance. Real-time tunneling processes are shown to be described by those complex saddle points, and thus semi-classical description of real-time quantum tunneling becomes possible on solid ground if we could solve that problem. - Highlights: • Real-time path integral is studied based on Picard–Lefschetz theory. • Lucid demonstration is given through simple examples of quantum mechanics. • This technique is applied to quantum mechanics of the double-well potential. • Difficulty for practical applications is revealed, and we discuss its generality. • Quantum tunneling is shown to be closely related to complex classical solutions.
The macroevolutionary consequences of phenotypic integration: from development to deep time
Goswami, A.; Smaers, J. B.; Soligo, C.; Polly, P. D.
2014-01-01
Phenotypic integration is a pervasive characteristic of organisms. Numerous analyses have demonstrated that patterns of phenotypic integration are conserved across large clades, but that significant variation also exists. For example, heterochronic shifts related to different mammalian reproductive strategies are reflected in postcranial skeletal integration and in coordination of bone ossification. Phenotypic integration and modularity have been hypothesized to shape morphological evolution, and we extended simulations to confirm that trait integration can influence both the trajectory and magnitude of response to selection. We further demonstrate that phenotypic integration can produce both more and less disparate organisms than would be expected under random walk models by repartitioning variance in preferred directions. This effect can also be expected to favour homoplasy and convergent evolution. New empirical analyses of the carnivoran cranium show that rates of evolution, in contrast, are not strongly influenced by phenotypic integration and show little relationship to morphological disparity, suggesting that phenotypic integration may shape the direction of evolutionary change, but not necessarily the speed of it. Nonetheless, phenotypic integration is problematic for morphological clocks and should be incorporated more widely into models that seek to accurately reconstruct both trait and organismal evolution. PMID:25002699
NASA Astrophysics Data System (ADS)
Tu, Rui; Wang, Li
2014-01-01
A method of real-time coseismic wave retrieving was proposed based on the tight integration of GPS, Glonass and strong-motion sensor observations, the validation and precision analysis have been made by an experimental data. The series of results have been shown that: by the integrated Kalman filter and multi-sensors, the coseismic waves can be optimally recovered by complement the advantages of each other, especially when the observation conditions are very bad. In additional, the results are not significantly effected by different receiver clock error processes for the integration solution.
Barlow, M. Rose; Chu, James A.
2014-01-01
Background Some people with dissociative identity disorder (DID) have very little communication or awareness among the parts of their identity, while others experience a great deal of cooperation among alternate identities. Previous research on this topic has been sparse. Currently, there is no empirical measure of integration versus fragmentation in a person with DID. In this study, we report the development of such a measure. Objective The goal of this study was to pilot the integration measure (IM) and to address its psychometric properties and relationships to other measures. The IM is the first standardized measure of integration in DID. Method Eleven women with DID participated in an experiment that included a variety of tasks. They filled out questionnaires about trauma and dissociation as well as the IM. They also provided verbal results about switching among alternate identities during the study sessions. Results Participants switched among identities an average of 5.8 times during the first session, and switching was highly correlated with trauma. Integration was related to switching, though this relationship may be non-linear. Integration was not related to time in psychotherapy. Conclusions The IM provides a useful beginning to quantify and study integration and fragmentation in DID. Directions for future research are also discussed, including expanding the IM from this pilot. The IM may be useful in treatment settings to assess progress or change over time. PMID:24396569
NASA Astrophysics Data System (ADS)
Allen, George I.; Matthews, Robert; Wynn, Michael
2001-10-01
In keeping with the Navy's policy to remove humans from harms way, the Autonomous Underwater Vehicle (AUV) is replacing human divers for many missions. The Advanced Marine Systems Lab at Florida Atlantic University (FAU) has developed a small, magnetically friendly, modular plastic AUV called Morpheus designed for coastal applications and especially suited for very shallow water (VSW) mine reconnaissance. Currently employed sensor technologies on AUVs have certain deficiencies and limitations when used across the wide gamut of naval targets and environments, and a strong requirement exists for a sensor or sensors to fill these niches. The Real-time Tracking Gradiometer (RTG) selected for this integration is truly such a niche sensor because its capabilities are not degraded by media interfaces or environmental conditions. It is an experimental prototype fluxgate magnetometer array developed by Quantum Magnetics for the Coastal Systems Station (CSS) and was designed to be man portable and self contained. While limited by physics in detection range, it is capable of detecting ferrous targets under the worst environmental conditions, even when the target is buried. While not having the range of sonar, the RTG does not respond to the false alarms that are indicated by sonar, and since it is capable of also providing range and bearing information, it provides an invaluable niche filling classification tool. The placing of any magnetic sensing system on a conventional AUV is a non-trivial problem. The standard AUV is designed around materials and components that were selected to maximize performance without regard to the magnetic properties of the materials used in its fabrication. To minimize the degradation of sensor performance caused by the platform, several steps must be taken. These include; the substitution of nonferrous components for ferrous, maximizing the separation between the sensor and magnetic field sources, minimizing current loops and using auxiliary
Chiang, Kai-Wei; Duong, Thanh Trung; Liao, Jhen-Kai
2013-01-01
The integration of an Inertial Navigation System (INS) and the Global Positioning System (GPS) is common in mobile mapping and navigation applications to seamlessly determine the position, velocity, and orientation of the mobile platform. In most INS/GPS integrated architectures, the GPS is considered to be an accurate reference with which to correct for the systematic errors of the inertial sensors, which are composed of biases, scale factors and drift. However, the GPS receiver may produce abnormal pseudo-range errors mainly caused by ionospheric delay, tropospheric delay and the multipath effect. These errors degrade the overall position accuracy of an integrated system that uses conventional INS/GPS integration strategies such as loosely coupled (LC) and tightly coupled (TC) schemes. Conventional tightly coupled INS/GPS integration schemes apply the Klobuchar model and the Hopfield model to reduce pseudo-range delays caused by ionospheric delay and tropospheric delay, respectively, but do not address the multipath problem. However, the multipath effect (from reflected GPS signals) affects the position error far more significantly in a consumer-grade GPS receiver than in an expensive, geodetic-grade GPS receiver. To avoid this problem, a new integrated INS/GPS architecture is proposed. The proposed method is described and applied in a real-time integrated system with two integration strategies, namely, loosely coupled and tightly coupled schemes, respectively. To verify the effectiveness of the proposed method, field tests with various scenarios are conducted and the results are compared with a reliable reference system. PMID:23955434
Chiang, Kai-Wei; Duong, Thanh Trung; Liao, Jhen-Kai
2013-01-01
The integration of an Inertial Navigation System (INS) and the Global Positioning System (GPS) is common in mobile mapping and navigation applications to seamlessly determine the position, velocity, and orientation of the mobile platform. In most INS/GPS integrated architectures, the GPS is considered to be an accurate reference with which to correct for the systematic errors of the inertial sensors, which are composed of biases, scale factors and drift. However, the GPS receiver may produce abnormal pseudo-range errors mainly caused by ionospheric delay, tropospheric delay and the multipath effect. These errors degrade the overall position accuracy of an integrated system that uses conventional INS/GPS integration strategies such as loosely coupled (LC) and tightly coupled (TC) schemes. Conventional tightly coupled INS/GPS integration schemes apply the Klobuchar model and the Hopfield model to reduce pseudo-range delays caused by ionospheric delay and tropospheric delay, respectively, but do not address the multipath problem. However, the multipath effect (from reflected GPS signals) affects the position error far more significantly in a consumer-grade GPS receiver than in an expensive, geodetic-grade GPS receiver. To avoid this problem, a new integrated INS/GPS architecture is proposed. The proposed method is described and applied in a real-time integrated system with two integration strategies, namely, loosely coupled and tightly coupled schemes, respectively. To verify the effectiveness of the proposed method, field tests with various scenarios are conducted and the results are compared with a reliable reference system. PMID:23955434
Speciation of dissolved iodine: integrating nitrate uptake over time in the oceans
NASA Astrophysics Data System (ADS)
Wong, George T. F.; Hung, Chin-Chang
2001-01-01
The distributions of nitrate reductase activity (NRA), iodate and iodide were determined in May 1996 in the southern East China Sea in a transect that traversed across the upwelling center northeast of Taiwan where topographically induced upwelling occurred as the Kuroshio interacted with the shelf edge. Rationalized iodate (R-iodate or R-IO 3- in nM) and iodide (R-iodide or R-I - in nM), the concentrations of iodate and iodide normalized to a salinity of 35, were strongly correlated to each other so that [R-IO3-]=-1.06(±0.06)[R-I-]+424(±15), r 2=0.87. Since the slope was indistinguishable from -1 mol-IO 3- mol -1-I -, this implies that, if iodate is depleted in the surface oceans by biologically mediated uptake, it re-appears almost quantitatively as iodide so that little iodate is retained in the particulate phase. In the upwelling zone, R-iodate and R-iodide were also strongly correlated to NRA (in nM-N h -1) such that [R-IO3-]=-10.2(±1.0)NRA+392(±12), r 2=0.84, [R-I-]=9.8(±1.1)NRA+27(±5), r 2=0.76. Since NRA is an indicator of nitrate uptake and the source water to the upwelling zone, the Kuroshio Subsurface Water, is rich in iodate and almost devoid of iodide, these relationships are consistent with the conceptual model that iodate reduction and nitrate uptake occur in tandem through the activities of the enzyme nitrate reductase. Since NRA represents an instantaneous rate while [R-IO 3-] and [R-I -] are concentrations, these strong correlations also suggest that iodate reduction and hence nitrate uptake had operated at approximately constant rates during the residence time of the water in the upwelling zone. Thus, the depletion of iodate and the gain in iodide in the upwelled water relative to its source water were integrations of the uptake and reduction of iodate over this residence time. The slope of the relationship between R-iodate and NRA represented the product of this residence time and the biological discrimination of iodate reduction relative
Measurement of the 1s2s 1S0-1s2p 3P1 intercombination interval in helium-like silicon.
Redshaw, M; Myers, E G
2002-01-14
Using Doppler-tuned fast-beam laser spectroscopy the 1s2s 1S0-1s2p 3P1 intercombination interval in 28Si12+ has been measured to be 7230.5(2) cm(-1). The experiment made use of a single-frequency Nd:YAG (1.319 microm) laser and a high-finesse optical buildup cavity. The result provides a precision test of modern relativistic and QED atomic theory. PMID:11801009
Choreographing Change One Step at a Time: Integrating Technology in Teacher Education.
ERIC Educational Resources Information Center
Falba, Christy J.; Zehm, Stanley J.; Bean, Tom; Markos, Patricia A.; Dixon, Juli K; McKinney, Marilyn
The papers presented as part of this symposium explore several aspects of integrating technology in teacher education. The title paper, presented by Christy J. Falba, reports on a study to investigate the process and progress of integrating technology into university level teacher education courses from the perspective of the university…
Song, Linze; Shi, Qiang
2015-05-07
We present a new non-perturbative method to calculate the charge carrier mobility using the imaginary time path integral approach, which is based on the Kubo formula for the conductivity, and a saddle point approximation to perform the analytic continuation. The new method is first tested using a benchmark calculation from the numerical exact hierarchical equations of motion method. Imaginary time path integral Monte Carlo simulations are then performed to explore the temperature dependence of charge carrier delocalization and mobility in organic molecular crystals (OMCs) within the Holstein and Holstein-Peierls models. The effects of nonlocal electron-phonon interaction on mobility in different charge transport regimes are also investigated.
NASA Astrophysics Data System (ADS)
Song, Linze; Shi, Qiang
2015-05-01
We present a new non-perturbative method to calculate the charge carrier mobility using the imaginary time path integral approach, which is based on the Kubo formula for the conductivity, and a saddle point approximation to perform the analytic continuation. The new method is first tested using a benchmark calculation from the numerical exact hierarchical equations of motion method. Imaginary time path integral Monte Carlo simulations are then performed to explore the temperature dependence of charge carrier delocalization and mobility in organic molecular crystals (OMCs) within the Holstein and Holstein-Peierls models. The effects of nonlocal electron-phonon interaction on mobility in different charge transport regimes are also investigated.
Finn, John M.
2015-03-01
Properties of integration schemes for solenoidal fields in three dimensions are studied, with a focus on integrating magnetic field lines in a plasma using adaptive time stepping. It is shown that implicit midpoint (IM) and a scheme we call three-dimensional leapfrog (LF) can do a good job (in the sense of preserving KAM tori) of integrating fields that are reversible, or (for LF) have a 'special divergence-free' property. We review the notion of a self-adjoint scheme, showing that such schemes are at least second order accurate and can always be formed by composing an arbitrary scheme with its adjoint. We also review the concept of reversibility, showing that a reversible but not exactly volume-preserving scheme can lead to a fractal invariant measure in a chaotic region, although this property may not often be observable. We also show numerical results indicating that the IM and LF schemes can fail to preserve KAM tori when the reversibility property (and the SDF property for LF) of the field is broken. We discuss extensions to measure preserving flows, the integration of magnetic field lines in a plasma and the integration of rays for several plasma waves. The main new result of this paper relates to non-uniform time stepping for volume-preserving flows. We investigate two potential schemes, both based on the general method of Ref. [11], in which the flow is integrated in split time steps, each Hamiltonian in two dimensions. The first scheme is an extension of the method of extended phase space, a well-proven method of symplectic integration with non-uniform time steps. This method is found not to work, and an explanation is given. The second method investigated is a method based on transformation to canonical variables for the two split-step Hamiltonian systems. This method, which is related to the method of non-canonical generating functions of Ref. [35], appears to work very well.
Further studies to extend and test the area-time-integral technique applied to satellite data
NASA Technical Reports Server (NTRS)
Smith, Paul L.; Vonderhaar, Thomas H.
1993-01-01
The principal goal of this project is to establish relationships that would allow application of area-time integral (ATI) calculations based upon satellite data to estimate rainfall volumes. The research has been pursued using two different approaches, which for convenience can be designated as the 'fixed-threshold approach' and the 'variable-threshold approach'. In the former approach, an attempt is made to determine a single temperature threshold in the satellite infrared data that would yield ATI values for identifiable cloud clusters which are most closely related to the corresponding rainfall amounts. Results thus far have indicated that a strong correlation exists between the rain volumes and the satellite ATI values, but the optimum threshold for this relationship seems to differ from one geographic location to another. The difference is probably related to differences in the basic precipitation mechanisms that dominate in the different regions. The average rainfall rate associated with each cloudy pixel is also found to vary across the spectrum of ATI values. Work on the second, or 'variable-threshold', approach for determining the satellite ATI values was essentially suspended during this period due to exhaustion of project funds. Most of the ATI work thus far has dealt with cloud clusters from the Lagrangian or 'floating-target' point of view. For many purposes, however, the Eulerian or 'fixed-target' perspective is more appropriate. For a very large target area encompassing entire cluster life histories, the rain volume-ATI relationship would obviously be the same in either case. The important question for the Eulerian perspective is how small the fixed area can be made while maintaining consistency in that relationship.
NASA Astrophysics Data System (ADS)
Dai, Yongbo; Li, Peng; Liu, Yanju; Asundi, Anand; Leng, Jinsong
2014-08-01
Based on the combination of wavelength- and time-division multiplexing technique, a novel fiber Bragg grating (FBG) sensor multiplexing system is proposed, which can be used for monitoring the two-dimensional strain and temperature field distribution in large structures. The FBG sensing unit is encoded simultaneously in both wavelength and time domains. Using the semiconductor optical amplifier (SOA) resonant cavity technology, a large capacity multiplexing technology with mixed time-division and wave-division multiplexing (TDM+WDM) is presented. The sensor array contains many groups with each group composed of many sensors. The group is addressed by TDM mode and each sensor of the groups is accessed by WDM mode. Therefore, the total multiplexing capacity is multiplication of TDM and WDM. In theory, more than 1000 sensors can be multiplexed on one single fiber. The feasibility of the scheme was experimentally demonstrated through a sensor system with a two dimensional FBG sensing network with 5×5 sensors arrays. In addition, the strain/temperature distribution in an aluminum plate was measured at real time under different loading/heating by using above FBG sensing network.
A novel 512×8 ROIC with time-delayed-integration for MW infrared focal plane array
NASA Astrophysics Data System (ADS)
Zhang, Jun-ling; Feng, Qi; Chen, Hong-lei; Huang, Ai-bo; Ding, Rui-jun; Ni, Yun-zhi
2011-08-01
In this paper a novel 512×8 readout circuit (ROIC) with time delayed integration (TDI) for middle wave (MW) infrared focal plane array (IRFPA) is present. As we known TDI is delicately devised and used in readout circuit to effectively increase the integration time and reduce the photon noise. At the same time, the bucket-brigade device (BBD) structure is commonly used in TDI implementation due to its simplicity and small size in integration. We adopt eight-stage BBD structure to get higher Signal-to-Noise ratio (SNR) and achieve faster image scanning speed for linear IRFPA in the 3μm -5μm spectral band. Because the center distance between each pixel is 28μm×56μm, an input stage based on direct injection (DI) which has high injection ratio and small layout area is proved to be suitable in this design. The detector consists of two segments in a staggered format that reads out synchronously. In order to achieve high flexibility, integration time can be controlled and the defective pixels can be de-selection manually. Some other features such as bidirectional operation, integration time, readout mode, an adaptive charge capacity control method and power consumption are also discussed in this article. The novel 512×8 ROIC is fabricated with 0.6μm double poly double metal CMOS technology and interconnected with MW IRFPA using indium bump. The experiments show that our method can achieve good performance of integration of MW signal both at room temperature and at 77K low temperature. The power consumption of the circuit is about 30mW at 5V supply and the readout clock frequency is up to 4MHz.
Accurate exposure classification tools are required to link exposure with health effects in epidemiological studies. Although long-term integrated exposure measurements are a critical component of exposure assessment, the ability to include these measurements into epidemiologic...
Lee, Yong Woo; Lee, Duck Joo
2014-12-01
Kirchhoff's formula for the convective wave equation is derived using the generalized function theory. The generalized convective wave equation for a stationary surface is obtained, and the integral formulation, the convective Kirchhoff's formula, is derived. The formula has a similar form to the classical Kirchhoff's formula, but an additional term appears due to a moving medium effect. For convenience, the additional term is manipulated to a final form as the classical Kirchhoff's formula. The frequency domain boundary integral can be obtained from the current time domain boundary integral form. The derived formula is verified by comparison with the analytic solution of source in the uniform flow. The formula is also utilized as a boundary integral equation. Time domain boundary element method (BEM) analysis using the boundary integral equation is conducted, and the results show good agreement with the analytical solution. The formula derived here can be useful for sound radiation and scattering by arbitrary bodies in a moving medium in the time domain. PMID:25480045
Baumgartner, Joy Noel; da Silva, Tatiana Fernandes Carpinteiro; Valencia, Eliecer; Susser, Ezra
2013-01-01
Global mental health movements increasingly highlight the importance of social integration for individuals living with severe mental illnesses. However, this important individual-level outcome is rarely measured in programs. As part of RedeAmericas, a pilot regional randomized controlled trial of critical time intervention — task shifting — will be conducted, which includes social integration as an outcome measure. It is a time-limited care coordination model to enhance continuity of support for people with severe mental illness during critical periods of transition. Given the challenges of measuring social integration, particularly for a multi-country study with unique cultural contexts, this paper has described the measurement approach used to create a composite measure that uses items from disability and quality of life instruments in addition to other key items. PMID:24288454
Baumgartner, Joy Noel; da Silva, Tatiana Fernandes Carpinteiro; Valencia, Eliecer; Susser, Ezra
2012-01-01
Global mental health movements increasingly highlight the importance of social integration for individuals living with severe mental illnesses. However, this important individual-level outcome is rarely measured in programs. As part of RedeAmericas, a pilot regional randomized controlled trial of critical time intervention - task shifting - will be conducted, which includes social integration as an outcome measure. It is a time-limited care coordination model to enhance continuity of support for people with severe mental illness during critical periods of transition. Given the challenges of measuring social integration, particularly for a multi-country study with unique cultural contexts, this paper has described the measurement approach used to create a composite measure that uses items from disability and quality of life instruments in addition to other key items. PMID:24288454
Hoffman, A. J.; Lee, J. C.
2013-07-01
A new time-dependent neutron transport method based on the method of characteristics (MOC) has been developed. Whereas most spatial kinetics methods treat time dependence through temporal discretization, this new method treats time dependence by defining the characteristics to span space and time. In this implementation regions are defined in space-time where the thickness of the region in time fulfills an analogous role to the time step in discretized methods. The time dependence of the local source is approximated using a truncated Taylor series expansion with high order derivatives approximated using backward differences, permitting the solution of the resulting space-time characteristic equation. To avoid a drastic increase in computational expense and memory requirements due to solving many discrete characteristics in the space-time planes, the temporal variation of the boundary source is similarly approximated. This allows the characteristics in the space-time plane to be represented analytically rather than discretely, resulting in an algorithm comparable in implementation and expense to one that arises from conventional time integration techniques. Furthermore, by defining the boundary flux time derivative in terms of the preceding local source time derivative and boundary flux time derivative, the need to store angularly-dependent data is avoided without approximating the angular dependence of the angular flux time derivative. The accuracy of this method is assessed through implementation in the neutron transport code DeCART. The method is employed with variable-order local source representation to model a TWIGL transient. The results demonstrate that this method is accurate and more efficient than the discretized method. (authors)
Honeine, Jean-Louis; Schieppati, Marco
2014-01-01
Maintaining equilibrium is basically a sensorimotor integration task. The central nervous system (CNS) continually and selectively weights and rapidly integrates sensory inputs from multiple sources, and coordinates multiple outputs. The weighting process is based on the availability and accuracy of afferent signals at a given instant, on the time-period required to process each input, and possibly on the plasticity of the relevant pathways. The likelihood that sensory inflow changes while balancing under static or dynamic conditions is high, because subjects can pass from a dark to a well-lit environment or from a tactile-guided stabilization to loss of haptic inflow. This review article presents recent data on the temporal events accompanying sensory transition, on which basic information is fragmentary. The processing time from sensory shift to reaching a new steady state includes the time to (a) subtract or integrate sensory inputs; (b) move from allocentric to egocentric reference or vice versa; and (c) adjust the calibration of motor activity in time and amplitude to the new sensory set. We present examples of processes of integration of posture-stabilizing information, and of the respective sensorimotor time-intervals while allowing or occluding vision or adding or subtracting tactile information. These intervals are short, in the order of 1–2 s for different postural conditions, modalities and deliberate or passive shift. They are just longer for haptic than visual shift, just shorter on withdrawal than on addition of stabilizing input, and on deliberate than unexpected mode. The delays are the shortest (for haptic shift) in blind subjects. Since automatic balance stabilization may be vulnerable to sensory-integration delays and to interference from concurrent cognitive tasks in patients with sensorimotor problems, insight into the processing time for balance control represents a critical step in the design of new balance- and locomotion training devices
Honeine, Jean-Louis; Schieppati, Marco
2014-01-01
Maintaining equilibrium is basically a sensorimotor integration task. The central nervous system (CNS) continually and selectively weights and rapidly integrates sensory inputs from multiple sources, and coordinates multiple outputs. The weighting process is based on the availability and accuracy of afferent signals at a given instant, on the time-period required to process each input, and possibly on the plasticity of the relevant pathways. The likelihood that sensory inflow changes while balancing under static or dynamic conditions is high, because subjects can pass from a dark to a well-lit environment or from a tactile-guided stabilization to loss of haptic inflow. This review article presents recent data on the temporal events accompanying sensory transition, on which basic information is fragmentary. The processing time from sensory shift to reaching a new steady state includes the time to (a) subtract or integrate sensory inputs; (b) move from allocentric to egocentric reference or vice versa; and (c) adjust the calibration of motor activity in time and amplitude to the new sensory set. We present examples of processes of integration of posture-stabilizing information, and of the respective sensorimotor time-intervals while allowing or occluding vision or adding or subtracting tactile information. These intervals are short, in the order of 1-2 s for different postural conditions, modalities and deliberate or passive shift. They are just longer for haptic than visual shift, just shorter on withdrawal than on addition of stabilizing input, and on deliberate than unexpected mode. The delays are the shortest (for haptic shift) in blind subjects. Since automatic balance stabilization may be vulnerable to sensory-integration delays and to interference from concurrent cognitive tasks in patients with sensorimotor problems, insight into the processing time for balance control represents a critical step in the design of new balance- and locomotion training devices
Samet Y. Kadioglu
2011-12-01
We present a computational gas dynamics method based on the Spectral Deferred Corrections (SDC) time integration technique and the Piecewise Parabolic Method (PPM) finite volume method. The PPM framework is used to define edge averaged quantities which are then used to evaluate numerical flux functions. The SDC technique is used to integrate solution in time. This kind of approach was first taken by Anita et al in [17]. However, [17] is problematic when it is implemented to certain shock problems. Here we propose significant improvements to [17]. The method is fourth order (both in space and time) for smooth flows, and provides highly resolved discontinuous solutions. We tested the method by solving variety of problems. Results indicate that the fourth order of accuracy in both space and time has been achieved when the flow is smooth. Results also demonstrate the shock capturing ability of the method.
NASA Technical Reports Server (NTRS)
Gottlieb, D.; Turkel, E.
1980-01-01
New methods are introduced for the time integration of the Fourier and Chebyshev methods of solution for dynamic differential equations. These methods are unconditionally stable, even though no matrix inversions are required. Time steps are chosen by accuracy requirements alone. For the Fourier method both leapfrog and Runge-Kutta methods are considered. For the Chebyshev method only Runge-Kutta schemes are tested. Numerical calculations are presented to verify the analytic results. Applications to the shallow water equations are presented.
ERIC Educational Resources Information Center
Doerann-George, Judith
The Integrated Moving Average (IMA) model of time series, and the analysis of intervention effects based on it, assume random shocks which are normally distributed. To determine the robustness of the analysis to violations of this assumption, empirical sampling methods were employed. Samples were generated from three populations; normal,…
ERIC Educational Resources Information Center
Carlson, Joanne S.
2012-01-01
The primary purpose of this study was to determine the extent to which orientation, evaluation, and integration practices, along with other select job aspects and demographic characteristics, were correlated with and explained intent to stay among part-time clinical nursing faculty. A conceptual model was developed and tested. A researcher…
2014-06-01
ARKode is part of a software family called SUNDIALS: SUite of Nonlinear and Differential/ALgebraic equation Solvers [1]. The ARKode solver library provides an adaptive-step time integration package for stiff, nonstiff and multi-rate systems of ordinary differential equations (ODEs) using Runge Kutta methods [2].
NASA Astrophysics Data System (ADS)
Wahl, Michael; Röhlicke, Tino; Rahn, Hans-Jürgen; Buschmann, Volker; Bertone, Nick; Kell, Gerald
2013-05-01
Time Correlated Single Photon counting (TCSPC) with picosecond timing is a key method in many areas of applied physics. One of the most important areas is that of fluorescence lifetime measurement in biophysics and the life sciences. Precisely timed photon counting for the purpose of coincidence correlation is now also emerging as the most common approach to quantum state interpretation in experimental quantum optics. Therefore, time-correlated single photon counting electronics, traditionally mostly used in time-resolved fluorescence research are facing new challenges in different emerging areas. Consequently such instruments are undergoing a fresh cycle of innovation, some of which we try to highlight here. The new picosecond TCSPC system we present provides several interesting new features resulting from a high speed monolithic integration in one of the fastest semiconductor technologies available today. The result is a high timing resolution by direct digital conversion and a very short deadtime. Apart from conventional histogramming over a very long time span, we can implement continouos single photon recording modes hat allow picosecond timing of all photon events with respect both to a sync signal as well as on a virtually infinite time scale. Multiple timing channels can also be operated indpendently and in parallel, e.g. for picosecond correlation analysis between signals from multiple photon detectors.
Excitation and Ionization in H(1s)-H(1s) Collisions
Riley, Merle E.; Ritchie, A. Burke
1999-07-15
Hydrogen atom - hydrogen atom scattering is a prototype for many of the fundamental principles of atomic collisions. In this work we present an approximation to the H+H system for scattering in the intermediate energy regime of 1 to 100 keV. The approximation ignores electron exchange and two-electron excitation by assuming that one of the atoms is frozen in the 1s state. We allow for the evolution of the active electron by numerically solving the 3D Schroedinger equation. The results capture many features of the problem and are in harmony with recent theoretical studies. Excitation and ionization cross sections are computed and compared to other theory and experiment. New insight into the mechanism of excitation and ionization is inferred from the solutions.
NASA Technical Reports Server (NTRS)
Young, Steven D.; Harrah, Steven D.; deHaag, Maarten Uijt
2002-01-01
Terrain Awareness and Warning Systems (TAWS) and Synthetic Vision Systems (SVS) provide pilots with displays of stored geo-spatial data (e.g. terrain, obstacles, and/or features). As comprehensive validation is impractical, these databases typically have no quantifiable level of integrity. This lack of a quantifiable integrity level is one of the constraints that has limited certification and operational approval of TAWS/SVS to "advisory-only" systems for civil aviation. Previous work demonstrated the feasibility of using a real-time monitor to bound database integrity by using downward-looking remote sensing technology (i.e. radar altimeters). This paper describes an extension of the integrity monitor concept to include a forward-looking sensor to cover additional classes of terrain database faults and to reduce the exposure time associated with integrity threats. An operational concept is presented that combines established feature extraction techniques with a statistical assessment of similarity measures between the sensed and stored features using principles from classical detection theory. Finally, an implementation is presented that uses existing commercial-off-the-shelf weather radar sensor technology.
NASA Astrophysics Data System (ADS)
Florkowski, Wojciech; Ryblewski, Radoslaw
2016-06-01
We introduce a generalized relaxation-time-approximation form of the collision term in the Boltzmann kinetic equation that allows for using different relaxation times for elastic and inelastic collisions. The efficacy of the proposed framework is demonstrated with the numerical calculations that describe systems with different relations between the two relaxation times and the evolution time of the system.
Improved measurement of the 1s2s 1S0-1s2p 3P1 interval in heliumlike silicon.
DeVore, Thomas R; Crosby, David N; Myers, Edmund G
2008-06-20
Using colinear fast-beam laser spectroscopy with copropagating and counter-propagating beams we have measured the 1s2s 1S0-1s2p 3P1 intercombination interval in 28Si12+ with the result 7230.585(6) cm{-1}. The experiment made use of a dual-wavelength, high-finesse, power build-up cavity excited by single-frequency lasers at 1319 and 1450 nm. The result will provide a precision test of ab initio relativistic many-body atomic theory at moderate Z. PMID:18643579
Coutts, G.W.; Wiedwald, J.D.; Sewall, N.; Lagin, L.
1999-12-07
The National Ignition Facility, or NIF, currently under construction at the Lawrence Livermore National Laboratory will contain the world's most powerful laser. By the year 2003 the NIF laser will be a research tool allowing scientists a glimpse into plasma interactions that are equivalent to those found in the center of the sun. Every eight hours the NIF will generate 1.8 MJ of 351-nm light carried by 192 pulsed laser beams and focus it onto a pea-sized target. This will result in a fusion reaction between two isotopes of hydrogen, creating for a few hundred picoseconds stellar conditions. Synchronizing the beams and diagnosing the fusion reaction requires generation and delivery of over 1000 precisely timed triggers to a multitude of systems. The NIF Integrated Timing System (ITS) was developed to provide reliable, accurately timed triggers that allow each client system to operate independently during periods of shot preparation and maintenance, yet be coordinated to a few tens of picoseconds during the experiment. The ITS applies technologies developed for fiber communications and Two-Way Time Transfer, and integrates them by way of a computer communications network to achieve distributed control, dynamically configurable coordination and independent among timing channels, and integrated self-diagnostics.
NASA Astrophysics Data System (ADS)
Tu, Rui; Zhang, Pengfei; Zhang, Rui; Liu, Jinhai
2016-08-01
This paper has studied the key issues about integration of GNSS and strong-motion records for real-time earthquake monitoring. The validations show that the consistence of the coordinate system must be considered firstly to exclude the system bias between GNSS and strong-motion. The GNSS sampling rate is suggested about 1-5 Hz, and we should give the strong-motion's baseline shift with a larger dynamic noise as its variation is very swift. The initialization time of solving the baseline shift is less than one minute, and ambiguity resolution strategy is not greatly improved the solution. The data quality is very important for the solution, we advised to use multi-frequency and multi-system observations. These ideas give an important guide for real-time earthquake monitoring and early warning by the tight integration of GNSS and strong-motion records.
R. A. Berry; S. Y. Kadioglu
2012-05-01
The numerical simulation of multiphase flows in Light Water (Nuclear) Reactors, LWRs, for normal, accident, and off-normal operation, and for operational optimization must cover a huge disparity of transient time durations, from milliseconds to years. In addition, our recent work has shown that the application of classical Riemann approaches, which pervade modern computational fluid dynamics (CFD), suffer numerical accuracy degradation, especially for compressible liquid flows. In this setting, all-speed or Mach uniform methods are need which can be accurately and efficiently integrated over a very large range of time scales. Thus we need a multi-time-scale integration approach to compliment our previously documented multi-spatial-scale approach to multiphase flow modeling [1]. This report briefly summarizes our efforts in these areas.
Integrating Health and Sustainability: The Higher Education Sector as a Timely Catalyst
ERIC Educational Resources Information Center
Orme, J.; Dooris, M.
2010-01-01
Higher education is an influential sector with enormous potential to impact positively on health and sustainability. The purpose of this paper was to explore its emergent role as a key setting for promoting health and sustainability and for addressing their challenges in an integrated and coherent way. Acknowledging both the relative narrowness of…
INTERNATIONAL STANDARDS FOR RESEARCH INTEGRITY: AN IDEA WHOSE TIME HAS COME?
Resnik, David B.
2014-01-01
A movement to promulgate international ethics standards covering areas of conduct other than research with human subjects has now begun to gain momentum. This commentary explains why it is important to develop international research integrity standards and some of the problems that must be overcome to bring them to fruition. PMID:20183162
Office Hours as You Like Them: Integrating Real-Time Chats into the Course Media Mix.
ERIC Educational Resources Information Center
McKeage, Kim
2001-01-01
Reports on one professor's use of integrated synchronous electronic office hours (i.e., a "chat room") with asynchronous course conferencing (i.e., email) in a class on introductory marketing. Describes its uses, limitations, benefits, potential problems, and results from a student survey. (EV)
An efficient algorithm based on splitting for the time integration of the Schrödinger equation
NASA Astrophysics Data System (ADS)
Blanes, Sergio; Casas, Fernando; Murua, Ander
2015-12-01
We present a practical algorithm based on symplectic splitting methods intended for the numerical integration in time of the Schrödinger equation when the Hamiltonian operator is either time-independent or changes slowly with time. In the later case, the evolution operator can be effectively approximated in a step-by-step manner: first divide the time integration interval in sufficiently short subintervals, and then successively solve a Schrödinger equation with a different time-independent Hamiltonian operator in each of these subintervals. When discretized in space, the Schrödinger equation with the time-independent Hamiltonian operator obtained for each time subinterval can be recast as a classical linear autonomous Hamiltonian system corresponding to a system of coupled harmonic oscillators. The particular structure of this linear system allows us to construct a set of highly efficient schemes optimized for different precision requirements and time intervals. Sharp local error bounds are obtained for the solution of the linear autonomous Hamiltonian system considered in each time subinterval. Our schemes can be considered, in this setting, as polynomial approximations to the matrix exponential in a similar way as methods based on Chebyshev and Taylor polynomials. The theoretical analysis, supported by numerical experiments performed for different time-independent Hamiltonians, indicates that the new methods are more efficient than schemes based on Chebyshev polynomials for all tolerances and time interval lengths. The algorithm we present automatically selects, for each time subinterval, the most efficient splitting scheme (among several new optimized splitting methods) for a prescribed error tolerance and given estimates of the upper and lower bounds of the eigenvalues of the discretized version of the Hamiltonian operator.
NASA Astrophysics Data System (ADS)
Lyles, Patrick V.; Buford, James A., Jr.; Cosby, David S.; Mayhall, Anthony J.
2003-09-01
This paper describes the current research in integrating Personal Computer technology into the U.S. Army Aviation and Missile Command (AMCOM) Hardware-in-the-Loop (HWIL) facilities. Using both COTS hardware along with custom built interfaces; the system under development will be used to replace high-end graphics workstations that provide infrared image generation. Infrared scene generation is an integral component in the HWIL testing of missile seeker units. This functionality must be more accessible, portable, and affordable as HWIL testing becomes more integral and more widely distributed in the development life cycle of missile systems. The graphics system under development is designed to be a more feasible plug-in replacement for existing infrared scene generation systems. Real-time performance and support of existing interfaces to simulation computers, projectors, and missile components are the primary considerations in designing this system.
NASA Astrophysics Data System (ADS)
Monzo, J. M.; Ros, A.; Herrero-Bosch, V.; Perino, I. V.; Aliaga, R. J.; Gadea-Girones, R.; Colom-Palero, R. J.
2013-03-01
Improving timing resolution in positron emission tomography (PET), thus having fine time information of the detected pulses, is important to increase the reconstructed images signal to noise ratio (SNR) [1]. In the present work, an integrated circuit topology for time extraction of the incoming pulses is evaluated. An accurate simulation including the detector physics and the electronics with different configurations has been developed. The selected architecture is intended for a PET system based on a continuous scintillation crystal attached to a SiPM array. The integrated circuit extracts the time stamp from the first few photons generated when the gamma-ray interacts with the scintillator, thus obtaining the best time resolution. To get the time stamp from the detected pulses, a time to digital converter (TDC) array based architecture has been proposed as in [2] or [3]. The TDC input stage uses a current comparator to transform the analog signal into a digital signal. Individually configurable trigger levels allow us to avoid false triggers due to signal noise. Using a TDC per SiPM configuration results in a very area consuming integrated circuit. One solution to this problem is to join several SiPM outputs to one TDC. This reduces the number of TDCs but, on the other hand, the first photons will be more difficult to be detected. For this reason, it is important to simulate how the time resolution is degraded when the number of TDCs is reduced. Following this criteria, the best configuration will be selected considering the trade-off between achievable time resolution and the cost per chip. A simulation is presented that uses Geant4 for simulation of the physics process and, for the electronic blocks, spice and Matlab. The Geant4 stage simulates the gamma-ray interaction with the scintillator, the photon shower generation and the first stages of the SiPM. The electronics simulation includes an electrical model of the SiPM array and all the integrated circuitry
The relation of radar to cloud area-time integrals and implications for rain measurements from space
NASA Technical Reports Server (NTRS)
Atlas, David; Bell, Thomas L.
1992-01-01
The relationships between satellite-based and radar-measured area-time integrals (ATI) for convective storms are determined, and both are shown to depend on the climatological conditional mean rain rate and the ratio of the measured cloud area to the actual rain area of the storms. The GOES precipitation index of Arkin (1986) for convective storms, an area-time integral for satellite cloud areas, is shown to be related to the ATI for radar-observed rain areas. The quality of GPI-based rainfall estimates depends on how well the cloud area is related to the rain area and the size of the sampling domain. It is also noted that the use of a GOES cloud ATI in conjunction with the radar area-time integral will improve the accuracy of rainfall estimates and allow such estimates to be made in much smaller space-time domains than the 1-month and 5-deg boxes anticipated for the Tropical Rainfall Measuring Mission.
Integrated planning problem in supply chains with time-varying delivery
NASA Astrophysics Data System (ADS)
Wang, Hai-ying; Liu, Da-cheng; Ding, Hua; Guo, Fu
2011-10-01
We consider a serial supply chain consisting of a raw material supplier, a manufacturer, a distribution centre and a retailer in the presence of time-varying delivery between manufacturer facility and the retailer warehouse. Delivery time functions are developed based on practical data analysis and the cost models for both linear and non-linear delivery time functions are derived. Analytic solution for system with linear delivery times is derived and a search algorithm for system with non-linear delivery times is established. Finally, sensitivity analysis is made to help decision makers achieve a lower total cost in practice.
Integrative, Dynamic Structural Biology at Atomic Resolution—It’s About Time
van den Bedem, Henry; Fraser, James S.
2015-01-01
Biomolecules adopt a dynamic ensemble of conformations, each with the potential to interact with binding partners or perform the chemical reactions required for a multitude of cellular functions. Recent advances in X-ray crystallography, Nuclear Magnetic Resonance (NMR) spectroscopy, and other techniques are helping us realize the dream of seeing—in atomic detail—how different parts of biomolecules exchange between functional sub-states using concerted motions. Integrative structural biology has advanced our understanding of the formation of large macromolecular complexes and how their components interact in assemblies by leveraging data from many low-resolution methods. Here, we review the growing opportunities for integrative, dynamic structural biology at the atomic scale, contending there is increasing synergistic potential between X-ray crystallography, NMR, and computer simulations to reveal a structural basis for protein conformational dynamics at high resolution. PMID:25825836
Finn, John M.
2015-03-15
Properties of integration schemes for solenoidal fields in three dimensions are studied, with a focus on integrating magnetic field lines in a plasma using adaptive time stepping. It is shown that implicit midpoint (IM) and a scheme we call three-dimensional leapfrog (LF) can do a good job (in the sense of preserving KAM tori) of integrating fields that are reversible, or (for LF) have a “special divergence-free” (SDF) property. We review the notion of a self-adjoint scheme, showing that such schemes are at least second order accurate and can always be formed by composing an arbitrary scheme with its adjoint. We also review the concept of reversibility, showing that a reversible but not exactly volume-preserving scheme can lead to a fractal invariant measure in a chaotic region, although this property may not often be observable. We also show numerical results indicating that the IM and LF schemes can fail to preserve KAM tori when the reversibility property (and the SDF property for LF) of the field is broken. We discuss extensions to measure preserving flows, the integration of magnetic field lines in a plasma and the integration of rays for several plasma waves. The main new result of this paper relates to non-uniform time stepping for volume-preserving flows. We investigate two potential schemes, both based on the general method of Feng and Shang [Numer. Math. 71, 451 (1995)], in which the flow is integrated in split time steps, each Hamiltonian in two dimensions. The first scheme is an extension of the method of extended phase space, a well-proven method of symplectic integration with non-uniform time steps. This method is found not to work, and an explanation is given. The second method investigated is a method based on transformation to canonical variables for the two split-step Hamiltonian systems. This method, which is related to the method of non-canonical generating functions of Richardson and Finn [Plasma Phys. Controlled Fusion 54, 014004 (2012
Finn, John M.
2015-03-01
Properties of integration schemes for solenoidal fields in three dimensions are studied, with a focus on integrating magnetic field lines in a plasma using adaptive time stepping. It is shown that implicit midpoint (IM) and a scheme we call three-dimensional leapfrog (LF) can do a good job (in the sense of preserving KAM tori) of integrating fields that are reversible, or (for LF) have a 'special divergence-free' property. We review the notion of a self-adjoint scheme, showing that such schemes are at least second order accurate and can always be formed by composing an arbitrary scheme with its adjoint. Wemore » also review the concept of reversibility, showing that a reversible but not exactly volume-preserving scheme can lead to a fractal invariant measure in a chaotic region, although this property may not often be observable. We also show numerical results indicating that the IM and LF schemes can fail to preserve KAM tori when the reversibility property (and the SDF property for LF) of the field is broken. We discuss extensions to measure preserving flows, the integration of magnetic field lines in a plasma and the integration of rays for several plasma waves. The main new result of this paper relates to non-uniform time stepping for volume-preserving flows. We investigate two potential schemes, both based on the general method of Ref. [11], in which the flow is integrated in split time steps, each Hamiltonian in two dimensions. The first scheme is an extension of the method of extended phase space, a well-proven method of symplectic integration with non-uniform time steps. This method is found not to work, and an explanation is given. The second method investigated is a method based on transformation to canonical variables for the two split-step Hamiltonian systems. This method, which is related to the method of non-canonical generating functions of Ref. [35], appears to work very well.« less
Development of a CMOS integrated zero-crossing discriminator using analog continuous-time division
Jochmann, M.W.
1996-12-31
High resolution time spectroscopy experiments require circuit techniques that accurately mark the time arrival of events regardless of their amplitude. For this purpose zero-crossing techniques are generally used because of their independence of the signal amplitude. Since the output response of real voltage comparators is related to the input signal slope and overdrive, even these time-pickoff methods are burdened by an amplitude dependent time walk. Therefore a new time-pickoff circuit is proposed using analog continuous-time division to eliminate the undesired amplitude information. Based on a standard CMOS technology a first test version has been developed that is still under production. First promising SPICE simulations using the simulation parameters of an inexpensive 1.2 {mu}m CMOS technology have shown a time walk fairly below 200 ps (FWHM) over a 40 dB amplitude range and for input signal risetimes of 2 to 3 ns.
Carter, Adam G; Soler-Llavina, Gilberto J; Sabatini, Bernardo L
2007-08-15
Medium spiny neurons (MSNs) are the principal cells of the striatum and perform a central role in sensorimotor processing. MSNs must integrate many excitatory inputs located across their dendrites to fire action potentials and enable striatal function. However, the dependence of synaptic responses on the temporal and spatial distribution of these inputs remains unknown. Here, we use whole-cell recordings, two-photon microscopy, and two-photon glutamate uncaging to examine subthreshold synaptic integration in MSNs from acute rat brain slices. We find that synaptic responses can summate sublinearly, linearly, or supralinearly depending on the spatiotemporal pattern of activity. Repetitive activity at single inputs leads to sublinear summation, reflecting long-lived AMPA receptor desensitization. In contrast, asynchronous activity at multiple inputs generates linear summation, with synapses on neighboring spines functioning independently. Finally, synchronous activity at multiple inputs triggers supralinear summation at depolarized potentials, reflecting activation of NMDA receptors and L-type calcium channels. Thus, the properties of subthreshold integration in MSNs are determined by the distribution of synaptic inputs and the differential activation of multiple postsynaptic conductances. PMID:17699678
Developing a service model that integrates palliative care throughout cancer care: the time is now.
Partridge, Ann H; Seah, Davinia S E; King, Tari; Leighl, Natasha B; Hauke, Ralph; Wollins, Dana S; Von Roenn, Jamie Hayden
2014-10-10
Palliative care is a fundamental component of cancer care. As part of the 2011 to 2012 Leadership Development Program (LDP) of the American Society of Clinical Oncology (ASCO), a group of participants was charged with advising ASCO on how to develop a service model integrating palliative care throughout the continuum of cancer care. This article presents the findings of the LDP group. The group focused on the process of palliative care delivery in the oncology setting. We identified key elements for models of palliative care in various settings to be potentially equitable, sustainable, feasible, and acceptable, and here we describe a dynamic model for the integrated, simultaneous implementation of palliative care into oncology practice. We also discuss critical considerations to better integrate palliative care into oncology, including raising consciousness and educating both providers and the public about the importance of palliative care; coordinating palliative care efforts through strengthening affiliations and/or developing new partnerships; prospectively evaluating the impact of palliative care on patient and provider satisfaction, quality improvement, and cost savings; and ensuring sustainability through adequate reimbursement and incentives, including linkage of performance data to quality indicators, and coordination with training efforts and maintenance of certification requirements for providers. In light of these findings, we believe the confluence of increasing importance of incorporation of palliative care education in oncology education, emphasis on value-based care, growing use of technology, and potential cost savings makes developing and incorporating palliative care into current service models a meaningful goal. PMID:25199756
Real-time integrity monitoring of composite laminates with magnetostrictive sensory layer
NASA Astrophysics Data System (ADS)
Kumar, Anand; Bhattacharya, Bishakh
2008-12-01
Fundamental research and development in smart materials and structures have shown great potential for enhancing the functionality, serviceability and increased life span of civil and mechanical infrastructure systems. Researchers from diverse disciplines have been drawn into vigorous efforts to develop smart and intelligent structures that can monitor their own conditions, detect impending failure, control damage and adapt to changing environments. Smart structures are generally created through synthesis by combining sensing, processing and actuating elements integrated with conventional structural materials. The conventional non-destructive evaluation techniques are not very effective in monitoring the structural integrity of composite structures due to their micro-mechanical complexities. With the commercial availability of the magnetostrictive (MS) material Terfenol-D in particulate form, it is now feasible to develop particulate sensors to detect damage with minimum effect on structural integrity. In present investigation, the electromagnetic response in the MS layer at the onset of delamination in one of the weakest ply of the composite laminate has been analyzed. For the numerical analysis symmetric and asymmetric carbon epoxy laminates with one of its layers embedded with Terfenol-D particles have been taken. Terfenol-D layer experiences a change in stress due to onset of delamination causing a change in its magnetic state, which can be sensed as induced open circuit voltage in the sensing coil enclosing the laminate beam. The effect of material properties, lamination schemes and placement of MS layer on the sensing capabilities has been analyzed.
A Search for Invisible Decays of the Upsilon(1S)
Aubert, B.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Battaglia, M.; Brown, D.N.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G. /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /Naples U. /INFN, Naples /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison
2009-10-17
We search for invisible decays of the {Upsilon}(1S) meson using a sample of 91.4 x 10{sup 6} {Upsilon}(3S) mesons collected at the BABAR/PEP-II B Factory. We select events containing the decay {Upsilon}(3S) {yields} {pi}{sup +}{pi}{sup -} {Upsilon}(1S) and search for evidence of an undetectable {Upsilon}(1S) decay recoiling against the dipion system. We set an upper limit on the branching fraction {Beta}({Upsilon}(1S) {yields} invisible) < 3.0 x 10{sup ?4} at the 90% confidence level.
Search for invisible decays of the Upsilon(1S).
Aubert, B; Karyotakis, Y; Lees, J P; Poireau, V; Prencipe, E; Prudent, X; Tisserand, V; Garra Tico, J; Grauges, E; Martinelli, M; Palano, A; Pappagallo, M; Eigen, G; Stugu, B; Sun, L; Battaglia, M; Brown, D N; Hooberman, B; Kerth, L T; Kolomensky, Yu G; Lynch, G; Osipenkov, I L; Tackmann, K; Tanabe, T; Hawkes, C M; Soni, N; Watson, A T; Koch, H; Schroeder, T; Asgeirsson, D J; Hearty, C; Mattison, T S; McKenna, J A; Barrett, M; Khan, A; Randle-Conde, A; Blinov, V E; Bukin, A D; Buzykaev, A R; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Bondioli, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Martin, E C; Stoker, D P; Atmacan, H; Gary, J W; Liu, F; Long, O; Vitug, G M; Yasin, Z; Sharma, V; Campagnari, C; Hong, T M; Kovalskyi, D; Mazur, M A; Richman, J D; Beck, T W; Eisner, A M; Heusch, C A; Kroseberg, J; Lockman, W S; Martinez, A J; Schalk, T; Schumm, B A; Seiden, A; Wang, L; Winstrom, L O; Cheng, C H; Doll, D A; Echenard, B; Fang, F; Hitlin, D G; Narsky, I; Ongmongkolkul, P; Piatenko, T; Porter, F C; Andreassen, R; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Bloom, P C; Ford, W T; Gaz, A; Hirschauer, J F; Nagel, M; Nauenberg, U; Smith, J G; Wagner, S R; Ayad, R; Toki, W H; Wilson, R J; Feltresi, E; Hauke, A; Jasper, H; Karbach, T M; Merkel, J; Petzold, A; Spaan, B; Wacker, K; Kobel, M J; Nogowski, R; Schubert, K R; Schwierz, R; Bernard, D; Latour, E; Verderi, M; Clark, P J; Playfer, S; Watson, J E; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cecchi, A; Cibinetto, G; Fioravanti, E; Franchini, P; Luppi, E; Munerato, M; Negrini, M; Petrella, A; Piemontese, L; Santoro, V; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Contri, R; Guido, E; Lo Vetere, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Tosi, S; Chaisanguanthum, K S; Morii, M; Adametz, A; Marks, J; Schenk, S; Uwer, U; Bernlochner, F U; Klose, V; Lacker, H M; Lueck, T; Volk, A; Bard, D J; Dauncey, P D; Tibbetts, M; Behera, P K; Charles, M J; Mallik, U; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gao, Y Y; Gritsan, A V; Guo, Z J; Arnaud, N; Béquilleux, J; D'Orazio, A; Davier, M; Derkach, D; Firmino da Costa, J; Grosdidier, G; Le Diberder, F; Lepeltier, V; Lutz, A M; Malaescu, B; Pruvot, S; Roudeau, P; Schune, M H; Serrano, J; Sordini, V; Stocchi, A; Wormser, G; Lange, D J; Wright, D M; Bingham, I; Burke, J P; Chavez, C A; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Payne, D J; Touramanis, C; Bevan, A J; Clarke, C K; Di Lodovico, F; Sacco, R; Sigamani, M; Cowan, G; Paramesvaran, S; Wren, A C; Brown, D N; Davis, C L; Denig, A G; Fritsch, M; Gradl, W; Hafner, A; Alwyn, K E; Bailey, D; Barlow, R J; Jackson, G; Lafferty, G D; West, T J; Yi, J I; Anderson, J; Chen, C; Jawahery, A; Roberts, D A; Simi, G; Tuggle, J M; Dallapiccola, C; Salvati, E; Cowan, R; Dujmic, D; Fisher, P H; Henderson, S W; Sciolla, G; Spitznagel, M; Yamamoto, R K; Zhao, M; Patel, P M; Robertson, S H; Schram, M; Biassoni, P; Lazzaro, A; Lombardo, V; Palombo, F; Stracka, S; Cremaldi, L; Godang, R; Kroeger, R; Sonnek, P; Summers, D J; Zhao, H W; Simard, M; Taras, P; Nicholson, H; De Nardo, G; Lista, L; Monorchio, D; Onorato, G; Sciacca, C; Raven, G; Snoek, H L; Jessop, C P; Knoepfel, K J; LoSecco, J M; Wang, W F; Corwin, L A; Honscheid, K; Kagan, H; Kass, R; Morris, J P; Rahimi, A M; Sekula, S J; Wong, Q K; Blount, N L; Brau, J; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Castelli, G; Gagliardi, N; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; del Amo Sanchez, P; Ben-Haim, E; Bonneaud, G R; Briand, H; Chauveau, J; Hamon, O; Leruste, Ph; Marchiori, G; Ocariz, J; Perez, A; Prendki, J; Sitt, S; Gladney, L; Biasini, M; Manoni, E; Angelini, C; Batignani, G; Bettarini, S; Calderini, G; Carpinelli, M; Cervelli, A; Forti, F; Giorgi, M A; Lusiani, A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Lopes Pegna, D; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Anulli, F; Baracchini, E; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Jackson, P D; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Renga, F; Voena, C; Ebert, M; Hartmann, T; Schröder, H; Waldi, R; Adye, T; Franek, B; Olaiya, E O; Wilson, F F; Emery, S; Esteve, L; Hamel de Monchenault, G; Kozanecki, W; Vasseur, G; Yèche, Ch; Zito, M; Allen, M T; Aston, D; Bartoldus, R; Benitez, J F; Cenci, R; Coleman, J P; Convery, M R; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dunwoodie, W; Field, R C; Franco Sevilla, M; Fulsom, B G; Gabareen, A M; Graham, M T; Grenier, P; Hast, C; Innes, W R; Kaminski, J; Kelsey, M H; Kim, H; Kim, P; Kocian, M L; Leith, D W G S; Li, S; Lindquist, B; Luitz, S; Luth, V; Lynch, H L; MacFarlane, D B; Marsiske, H; Messner, R; Muller, D R; Neal, H; Nelson, S; O'Grady, C P; Ofte, I; Perl, M; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Va'vra, J; Wagner, A P; Weaver, M; West, C A; Wisniewski, W J; Wittgen, M; Wright, D H; Wulsin, H W; Yarritu, A K; Young, C C; Ziegler, V; Chen, X R; Liu, H; Park, W; Purohit, M V; White, R M; Wilson, J R; Bellis, M; Burchat, P R; Edwards, A J; Miyashita, T S; Ahmed, S; Alam, M S; Ernst, J A; Pan, B; Saeed, M A; Zain, S B; Soffer, A; Spanier, S M; Wogsland, B J; Eckmann, R; Ritchie, J L; Ruland, A M; Schilling, C J; Schwitters, R F; Wray, B C; Drummond, B W; Izen, J M; Lou, X C; Bianchi, F; Gamba, D; Pelliccioni, M; Bomben, M; Bosisio, L; Cartaro, C; Della Ricca, G; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martinez-Vidal, F; Milanes, D A; Oyanguren, A; Albert, J; Banerjee, Sw; Bhuyan, B; Choi, H H F; Hamano, K; King, G J; Kowalewski, R; Lewczuk, M J; Nugent, I M; Roney, J M; Sobie, R J; Gershon, T J; Harrison, P F; Ilic, J; Latham, T E; Mohanty, G B; Puccio, E M T; Band, H R; Chen, X; Dasu, S; Flood, K T; Pan, Y; Prepost, R; Vuosalo, C O; Wu, S L
2009-12-18
We search for invisible decays of the Upsilon(1S) meson using a sample of 91.4 x 10(6) Upsilon(3S) mesons collected at the BABAR/PEP-II B factory. We select events containing the decay Upsilon(3S) --> pi(+)pi(-)Upsilon(1S) and search for evidence of an undetectable Upsilon(1S) decay recoiling against the dipion system. We set an upper limit on the branching fraction B(Upsilon(1S) --> invisible) < 3.0 x 10(-4) at the 90% confidence level. PMID:20366249
Search for Invisible Decays of the Υ(1S)
NASA Astrophysics Data System (ADS)
Aubert, B.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Tico, J. Garra; Grauges, E.; Martinelli, M.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Battaglia, M.; Brown, D. N.; Hooberman, B.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Osipenkov, I. L.; Tackmann, K.; Tanabe, T.; Hawkes, C. M.; Soni, N.; Watson, A. T.; Koch, H.; Schroeder, T.; Asgeirsson, D. J.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Barrett, M.; Khan, A.; Randle-Conde, A.; Blinov, V. E.; Bukin, A. D.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Bondioli, M.; Curry, S.; Eschrich, I.; Kirkby, D.; Lankford, A. J.; Lund, P.; Mandelkern, M.; Martin, E. C.; Stoker, D. P.; Atmacan, H.; Gary, J. W.; Liu, F.; Long, O.; Vitug, G. M.; Yasin, Z.; Sharma, V.; Campagnari, C.; Hong, T. M.; Kovalskyi, D.; Mazur, M. A.; Richman, J. D.; Beck, T. W.; Eisner, A. M.; Heusch, C. A.; Kroseberg, J.; Lockman, W. S.; Martinez, A. J.; Schalk, T.; Schumm, B. A.; Seiden, A.; Wang, L.; Winstrom, L. O.; Cheng, C. H.; Doll, D. A.; Echenard, B.; Fang, F.; Hitlin, D. G.; Narsky, I.; Ongmongkolkul, P.; Piatenko, T.; Porter, F. C.; Andreassen, R.; Mancinelli, G.; Meadows, B. T.; Mishra, K.; Sokoloff, M. D.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Hirschauer, J. F.; Nagel, M.; Nauenberg, U.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Wilson, R. J.; Feltresi, E.; Hauke, A.; Jasper, H.; Karbach, T. M.; Merkel, J.; Petzold, A.; Spaan, B.; Wacker, K.; Kobel, M. J.; Nogowski, R.; Schubert, K. R.; Schwierz, R.; Bernard, D.; Latour, E.; Verderi, M.; Clark, P. J.; Playfer, S.; Watson, J. E.; Andreotti, M.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cecchi, A.; Cibinetto, G.; Fioravanti, E.; Franchini, P.; Luppi, E.; Munerato, M.; Negrini, M.; Petrella, A.; Piemontese, L.; Santoro, V.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Pacetti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Guido, E.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Tosi, S.; Chaisanguanthum, K. S.; Morii, M.; Adametz, A.; Marks, J.; Schenk, S.; Uwer, U.; Bernlochner, F. U.; Klose, V.; Lacker, H. M.; Lueck, T.; Volk, A.; Bard, D. J.; Dauncey, P. D.; Tibbetts, M.; Behera, P. K.; Charles, M. J.; Mallik, U.; Cochran, J.; Crawley, H. B.; Dong, L.; Eyges, V.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Rubin, A. E.; Gao, Y. Y.; Gritsan, A. V.; Guo, Z. J.; Arnaud, N.; Béquilleux, J.; D'Orazio, A.; Davier, M.; Derkach, D.; da Costa, J. Firmino; Grosdidier, G.; Le Diberder, F.; Lepeltier, V.; Lutz, A. M.; Malaescu, B.; Pruvot, S.; Roudeau, P.; Schune, M. H.; Serrano, J.; Sordini, V.; Stocchi, A.; Wormser, G.; Lange, D. J.; Wright, D. M.; Bingham, I.; Burke, J. P.; Chavez, C. A.; Fry, J. R.; Gabathuler, E.; Gamet, R.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Clarke, C. K.; di Lodovico, F.; Sacco, R.; Sigamani, M.; Cowan, G.; Paramesvaran, S.; Wren, A. C.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Hafner, A.; Alwyn, K. E.; Bailey, D.; Barlow, R. J.; Jackson, G.; Lafferty, G. D.; West, T. J.; Yi, J. I.; Anderson, J.; Chen, C.; Jawahery, A.; Roberts, D. A.; Simi, G.; Tuggle, J. M.; Dallapiccola, C.; Salvati, E.; Cowan, R.; Dujmic, D.; Fisher, P. H.; Henderson, S. W.; Sciolla, G.; Spitznagel, M.; Yamamoto, R. K.; Zhao, M.; Patel, P. M.; Robertson, S. H.; Schram, M.; Biassoni, P.; Lazzaro, A.; Lombardo, V.; Palombo, F.; Stracka, S.; Cremaldi, L.; Godang, R.; Kroeger, R.; Sonnek, P.; Summers, D. J.; Zhao, H. W.; Simard, M.; Taras, P.; Nicholson, H.; de Nardo, G.; Lista, L.; Monorchio, D.; Onorato, G.; Sciacca, C.; Raven, G.; Snoek, H. L.; Jessop, C. P.; Knoepfel, K. J.; Losecco, J. M.; Wang, W. F.; Corwin, L. A.; Honscheid, K.; Kagan, H.; Kass, R.; Morris, J. P.; Rahimi, A. M.; Sekula, S. J.; Wong, Q. K.; Blount, N. L.; Brau, J.; Frey, R.; Igonkina, O.; Kolb, J. A.; Lu, M.; Rahmat, R.; Sinev, N. B.; Strom, D.; Strube, J.; Torrence, E.; Castelli, G.; Gagliardi, N.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Voci, C.; Del Amo Sanchez, P.; Ben-Haim, E.; Bonneaud, G. R.; Briand, H.; Chauveau, J.; Hamon, O.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Perez, A.; Prendki, J.; Sitt, S.; Gladney, L.; Biasini, M.; Manoni, E.; Angelini, C.; Batignani, G.; Bettarini, S.; Calderini, G.; Carpinelli, M.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Morganti, M.; Neri, N.; Paoloni, E.; Rizzo, G.; Walsh, J. J.; Pegna, D. Lopes; Lu, C.; Olsen, J.; Smith, A. J. S.; Telnov, A. V.; Anulli, F.; Baracchini, E.; Cavoto, G.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Jackson, P. D.; Gioi, L. Li; Mazzoni, M. A.; Morganti, S.; Piredda, G.; Renga, F.; Voena, C.; Ebert, M.; Hartmann, T.; Schröder, H.; Waldi, R.; Adye, T.; Franek, B.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Esteve, L.; de Monchenault, G. Hamel; Kozanecki, W.; Vasseur, G.; Yèche, Ch.; Zito, M.; Allen, M. T.; Aston, D.; Bartoldus, R.; Benitez, J. F.; Cenci, R.; Coleman, J. P.; Convery, M. R.; Dingfelder, J. C.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Field, R. C.; Sevilla, M. Franco; Fulsom, B. G.; Gabareen, A. M.; Graham, M. T.; Grenier, P.; Hast, C.; Innes, W. R.; Kaminski, J.; Kelsey, M. H.; Kim, H.; Kim, P.; Kocian, M. L.; Leith, D. W. G. S.; Li, S.; Lindquist, B.; Luitz, S.; Luth, V.; Lynch, H. L.; Macfarlane, D. B.; Marsiske, H.; Messner, R.; Muller, D. R.; Neal, H.; Nelson, S.; O'Grady, C. P.; Ofte, I.; Perl, M.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Schindler, R. H.; Schwiening, J.; Snyder, A.; Su, D.; Sullivan, M. K.; Suzuki, K.; Swain, S. K.; Thompson, J. M.; Va'Vra, J.; Wagner, A. P.; Weaver, M.; West, C. A.; Wisniewski, W. J.; Wittgen, M.; Wright, D. H.; Wulsin, H. W.; Yarritu, A. K.; Young, C. C.; Ziegler, V.; Chen, X. R.; Liu, H.; Park, W.; Purohit, M. V.; White, R. M.; Wilson, J. R.; Bellis, M.; Burchat, P. R.; Edwards, A. J.; Miyashita, T. S.; Ahmed, S.; Alam, M. S.; Ernst, J. A.; Pan, B.; Saeed, M. A.; Zain, S. B.; Soffer, A.; Spanier, S. M.; Wogsland, B. J.; Eckmann, R.; Ritchie, J. L.; Ruland, A. M.; Schilling, C. J.; Schwitters, R. F.; Wray, B. C.; Drummond, B. W.; Izen, J. M.; Lou, X. C.; Bianchi, F.; Gamba, D.; Pelliccioni, M.; Bomben, M.; Bosisio, L.; Cartaro, C.; Della Ricca, G.; Lanceri, L.; Vitale, L.; Azzolini, V.; Lopez-March, N.; Martinez-Vidal, F.; Milanes, D. A.; Oyanguren, A.; Albert, J.; Banerjee, Sw.; Bhuyan, B.; Choi, H. H. F.; Hamano, K.; King, G. J.; Kowalewski, R.; Lewczuk, M. J.; Nugent, I. M.; Roney, J. M.; Sobie, R. J.; Gershon, T. J.; Harrison, P. F.; Ilic, J.; Latham, T. E.; Mohanty, G. B.; Puccio, E. M. T.; Band, H. R.; Chen, X.; Dasu, S.; Flood, K. T.; Pan, Y.; Prepost, R.; Vuosalo, C. O.; Wu, S. L.
2009-12-01
We search for invisible decays of the Υ(1S) meson using a sample of 91.4×106 Υ(3S) mesons collected at the BABAR/PEP-II B factory. We select events containing the decay Υ(3S)→π+π-Υ(1S) and search for evidence of an undetectable Υ(1S) decay recoiling against the dipion system. We set an upper limit on the branching fraction B(Υ(1S)→invisible)<3.0×10-4 at the 90% confidence level.
The novel function of JADE1S in cytokinesis of epithelial cells
Siriwardana, Nirodhini S; Meyer, Rosana D; Panchenko, Maria V
2015-01-01
JADE1 belongs to a small family of PHD zinc finger proteins that interacts with histone acetyl transferase (HAT) HBO1 and is associated with chromatin. We recently reported JADE1 chromatin shuttling and phosphorylation during G2/M to G1 transition, which was sensitive to Aurora A inhibition. In the current study we examined mechanisms of the cell cycle regulation by the small isoform of JADE1 protein, JADE1S, and report data showing that JADE1S has a novel function in the regulation of cytokinesis. Using FACS assays, we show that, JADE1S depletion facilitated rates of G1-cells accumulation in synchronously dividing HeLa cell cultures. Depletion of JADE1S protein in asynchronously dividing cells decreased the proportion of cytokinetic cells, and increased the proportion of multi-nuclear cells, indicative of premature and failed cytokinesis. In contrast, moderate overexpression of JADE1S increased the number of cytokinetic cells in time- and dose- dependent manner, indicating cytokinetic delay. Pharmacological inhibition of Aurora B kinase resulted in the release of JADE1S-mediated cytokinetic delay and allowed progression of abscission in cells over-expressing JADE1S. Finally, we show that JADE1S protein localized to centrosomes in interphase and mitotic cells, while during cytokinesis JADE1S localized to the midbody. Neither JADE1L nor partner of JADE1, HAT HBO1 was localized to the centrosomes or midbodies. Our study identifies the novel role for JADE1S in regulation of cytokinesis and suggests function in Aurora B kinase-mediated cytokinesis checkpoint. PMID:26151225
Belala, R; Briand-Amirat, L; Vinciguerra, L; Tainturier, D; Kaidi, R; Thorin, C; Michaud, S; Anton, M; Bencharif, D
2016-06-01
The present work aimed to assess the effect of equilibration time on post-thaw motility parameters of canine sperm frozen in three extenders: 6% low-density lipoproteins (LDL), 6% liposomes (LIPO), and 40% egg yolk plasma (EYP). A second experiment is aimed at evaluating the functional integrity of canine spermatozoa frozen in the three extenders at the best equilibration time found in the experiment one. In the first experiment, 20 ejaculates harvested from 7 dogs, were frozen in three extenders (LDL, LIPO, and EYP) after four equilibration times (30min, 1h, 3h, and 6h). The semen was evaluated after thawing using an image analyser (HT-IVOS 14.0). The 6h equilibration time gave better results of motility and progressive motility in the three studied extenders. (LDL: 58.9% vs. 42.7%; LIPO: 54.4% vs. 31.9%; EYP: 55.4% vs 40.5% for motility 6 vs. 1h). In the second experiment, 10 ejaculates taken from 6 dogs were frozen under the same conditions as the previous experiment, after 6h equilibration time. The integrity parameters of the spermatozoal membrane (hypo-osmotic swelling test, and SYBR14/propidium Iodide staining), acrosome (FITC-Pisium sativum Aglutinin staining), and DNA (acridine orange staining) were evaluated at three different stages: post-dilution (T0), post-equilibration, and post-thawing. Post-thaw results were as follows: membrane integrity (HOSt: 62;6% vs 58% vs 64.4%; SYBR14/IP: 63.6% vs 57.9% vs 64.8%); acrosome integrity (FITC-PSA: 79.4% vs 74% vs 76.2%) and DNA integrity (Acridine-orange: 98.9% vs 98.5% vs 98.7%) respectively for LDL vs. LIPO vs. EYP. No significant difference existed between the extenders tested; thus 6%LIPO and 40%EYP could be good candidates for replacement of 6%LDL in the protection of canine sperm during the freeze-thaw process without altering motility and integrity parameters. PMID:27234538
NASA Astrophysics Data System (ADS)
McLeod, R.; Hawkins, R. J.; Kallman, J. S.
1991-04-01
Interest has recently grown in applying microwave modeling techniques to optical circuit modeling. One of the simplest, yet most powerful, microwave simulation techniques is the finite-difference time-domain algorithm (FDTD). In this technique, the differential form of the time-domain Maxwell's equations are discretized and all derivatives are approximated as differences. Minor algebraic manipulations on the resulting equations produces a set of update equations that produce fields at a given time step from fields at the previous time step. The FDTD algorithm, then, is quite simple. Source fields are launched into the discrete grid by some means. The FDTD equations advance these fields in time. At the boundaries of the grid, special update equations called radiation conditions are applied that approximate a continuing, infinite space. Because virtually no assumptions are made in the development of the FDTD method, the algorithm is able to represent a wide-range of physical effects. Waves can propagate in any direction, multiple reflections within structures can cause resonances, multiple modes of various polarizations can be launched, each of which may generate within the device an infinite spectrum of bound and radiation modes. The ability to model these types of general physical effects is what makes the FDTD method interesting to the field of optics. In this paper, we discuss the application of the finite-difference time-domain technique to integrated optics. Animations will be shown of the simulations of a TE coupler, TM grating, and a TE integrated detector.
NASA Astrophysics Data System (ADS)
Mateescu, D.; Païdoussis, M. P.; Belanger, F.
1994-07-01
The paper presents 2-D and 3-D computational solutions for unsteady annular viscous flows with oscillating boundaries. A time-integration method based on a three-time-level implicit semi-discretization is first formulated in cylindrical coordinates for solving the time-dependent incompressible Navier-Stokes equations. This methods uses a pseudo-time integration with artificial compressibility to advance the solution between consecutive real time levels, and a finite-difference spatial discretization based on a stretched staggered grid. A decoupling procedure based on a factored ADI scheme with lagged nonlinearities reduces the problem to the solution of scalar tridiagonal systems. As a result, this method displays very good computing efficiency and accuracy in all numerical examples analysed. The method is first validated for axisymmetric flow over an annular backstep, by comparison with previous results, and is then employed to analyse 2-D unsteady annular flows due to transverse oscillations of the outer boundary. The results obtained with this method are free of spurious, numerically induced, oscillations in the unsteady pressure, which otherwise arise if a Crank-Nicolson scheme is used instead for time-discretization.The 3-D case of oscillating boundaries in annular axial flow is also analysed with this method by considering a fully developed viscous axial flow between two concentric cylinders when the central portion of the outer cylinder executes transverse translational oscillations; the computational solution thus obtained is of interest in the study of flow-induced vibration problems in such configurations.
Kirkham, R.; Siddons, D.; Dunn, P.A.; Kuczewski, A.J.; Dodanwela, R.; Moorhead, G.F.; Ryan, C.G.; De Geronimo, G.; Beuttenmuller, R.; Pinelli, D.; Pfeffer, M.; Davey, P.; Jensen, M.; de Jonge, M.D.; Howard, D.L.; Kusel, M.; McKinlay, J.
2010-06-23
The Maia detector system is engineered for energy dispersive x-ray fluorescence spectroscopy and elemental imaging at photon rates exceeding 10{sup 7}/s, integrated scanning of samples for pixel transit times as small as 50 {micro}s and high definition images of 10{sup 8} pixels and real-time processing of detected events for spectral deconvolution and online display of pure elemental images. The system developed by CSIRO and BNL combines a planar silicon 384 detector array, application-specific integrated circuits for pulse shaping and peak detection and sampling and optical data transmission to an FPGA-based pipelined, parallel processor. This paper describes the system and the underpinning engineering solutions.
NASA Technical Reports Server (NTRS)
Doneaud, Andre A.; Miller, James R., Jr.; Johnson, L. Ronald; Vonder Haar, Thomas H.; Laybe, Patrick
1987-01-01
The use of the area-time-integral (ATI) technique, based only on satellite data, to estimate convective rain volume over a moving target is examined. The technique is based on the correlation between the radar echo area coverage integrated over the lifetime of the storm and the radar estimated rain volume. The processing of the GOES and radar data collected in 1981 is described. The radar and satellite parameters for six convective clusters from storm events occurring on June 12 and July 2, 1981 are analyzed and compared in terms of time steps and cluster lifetimes. Rain volume is calculated by first using the regression analysis to generate the regression equation used to obtain the ATI; the ATI versus rain volume relation is then employed to compute rain volume. The data reveal that the ATI technique using satellite data is applicable to the calculation of rain volume.
Song, Linze; Shi, Qiang
2015-05-01
We present a new non-perturbative method to calculate the charge carrier mobility using the imaginary time path integral approach, which is based on the Kubo formula for the conductivity, and a saddle point approximation to perform the analytic continuation. The new method is first tested using a benchmark calculation from the numerical exact hierarchical equations of motion method. Imaginary time path integral Monte Carlo simulations are then performed to explore the temperature dependence of charge carrier delocalization and mobility in organic molecular crystals (OMCs) within the Holstein and Holstein-Peierls models. The effects of nonlocal electron-phonon interaction on mobility in different charge transport regimes are also investigated. PMID:25956086
NASA Technical Reports Server (NTRS)
Thompson, R. R.; Blum, H. A.
1971-01-01
This paper is concerned with the computer costs for both the steady-state and transient thermal responses of large-scale integrated circuits (LSI) when metal is present within the substrate. For the more cost-sensitive transient case, an extrapolation technique for computer time savings is compared with the accuracy loss in this study. This approach could be useful for design-cost planning.
Real-time in situ sensors and control integration for life support systems
NASA Technical Reports Server (NTRS)
Voecks, G. E.; Seshan, P. K.
1991-01-01
The limitations of the state-of-the-art for in situ sensors are discussed and a program of adaptation and enhancement of off-the-shelf sensor technologies and of innovation and research to develop more appropriate sensor technologies for life support systems is offered. By critically assessing the state-of-the-art in multifunctional sensors and smart sensors, research and development requirements for life support systems can be defined. Consideration is given to the desirable characteristics of smart sensors for life support applications, and some preliminary concepts for hierarchical integration of in situ sensors and control elements are presented.
NASA Technical Reports Server (NTRS)
Bogart, Edward H. (Inventor); Pope, Alan T. (Inventor)
2000-01-01
A system for display on a single video display terminal of multiple physiological measurements is provided. A subject is monitored by a plurality of instruments which feed data to a computer programmed to receive data, calculate data products such as index of engagement and heart rate, and display the data in a graphical format simultaneously on a single video display terminal. In addition live video representing the view of the subject and the experimental setup may also be integrated into the single data display. The display may be recorded on a standard video tape recorder for retrospective analysis.
Integral definition of transition time in the Landau-Zener model
Yan Yue; Wu Biao
2010-02-15
We give a general definition for the transition time in the Landau-Zener model. This definition allows us to compute numerically the Landau-Zener transition time at any sweeping rate without ambiguity in both diabatic and adiabatic bases. With this new definition, analytical results are obtained in both the adiabatic limit and the sudden limit.
NASA Astrophysics Data System (ADS)
Symeonidis, Vasileios; Karniadakis, George Em
2006-10-01
We propose new schemes for integrating the stochastic differential equations of dissipative particle dynamics (DPD) in simulations of dilute polymer solutions. The hybrid DPD models consist of hard potentials that describe the microscopic dynamics of polymers and soft potentials that describe the mesoscopic dynamics of the solvent. In particular, we develop extensions to the velocity-Verlet and Lowe's approaches - two representative DPD time-integrators - following a subcycling procedure whereby the solvent is advanced with a timestep much larger than the one employed in the polymer time-integration. The introduction of relaxation parameters allows optimization studies for accuracy while maintaining the low computational complexity of standard DPD algorithms. We demonstrate through equilibrium simulations that a 10-fold gain in efficiency can be obtained with the time-staggered algorithms without loss of accuracy compared to the non-staggered schemes. We then apply the new approach to investigate the scaling response of polymers in equilibrium as well as the dynamics of λ-phage DNA molecules subjected to shear.
NASA Astrophysics Data System (ADS)
El-Desouki, Munir M.; Al-Azem, Badeea
2014-03-01
Time-delay integration (TDI) is a popular imaging technique that is used in many applications such as machine vision, dental scanning and satellite earth observation. One of the main advantages of using TDI imagers is the increased effective integration time that is achieved while maintaining high frame-rates. Another use for TDI imagers is with moving objects, such as the earth's surface or industrial machine vision applications, where integration time is limited in order to avoid motion blurs. Such technique may even find its way in mobile and consumer based imaging applications where the reduction in pixel size can limit the performance during low-light and high speed applications. Until recently, TDI was only used with charge-coupled devices (CCDs) mainly due to their charge transfer characteristics. CCDs however, are power consuming and slow when compared to CMOS technology and are no longer favorable for mobile applications. In this work, we report on novel single-photon counting based TDI technique that is implemented in standard CMOS technology allowing for complete camera-on-a-chip solution. The imager was fabricated in a standard CMOS 150 nm 5-metal digital process from LFoundry.
Integrating health and sustainability: the higher education sector as a timely catalyst.
Orme, J; Dooris, M
2010-06-01
Higher education is an influential sector with enormous potential to impact positively on health and sustainability. The purpose of this paper was to explore its emergent role as a key setting for promoting health and sustainability and for addressing their challenges in an integrated and coherent way. Acknowledging both the relative narrowness of the environmental focus that has to date characterized and driven universities' work in relation to sustainability and the demonstrable value of adopting a whole-system approach, this paper will explore the concept of 'Healthy Universities' as a means of furthering debate and facilitating synergy between public health, sustainable development and climate change. Higher education represents one large-scale sector with a unique combination of roles that can be harnessed to focus and mobilize its education, knowledge exchange, research, corporate responsibility and future shaping agendas to achieve significant impacts in this area. It is the growing commitment to embedding health and well-being within the mainstream business of higher education coupled with the expectation that universities will act sustainably in all that they do that provides the perfect springboard to influence a process of 'co-ordinated action' to address climate change and impact positively on the integrated health and sustainability agenda. PMID:20382673
Real-time three-dimensional pickup and display system based on integral photography
NASA Astrophysics Data System (ADS)
Okano, Fumio; Arai, Jun; Hoshino, Haruo; Yuyama, Ichiro
1998-12-01
A real-time three-dimensional (3-D) pickup and display setup called a Real-time IP system is proposed. In this system, erected real images of an object are formed by a GRIN lens array as element images, and are directly shot by a television camera. The video signal of a group of element images is transmitted to display device that combines a liquid crystal panel display and a convex micro-lens array, producing a color 3-D image in real-time. Full-color and autostereoscopic 3-D images with full-parallax can be observed. We confirmed the possibility of the 3-D television system.
Tierney, Adam; Kraus, Nina
2016-03-01
The auditory system is unique in its ability to precisely detect the timing of perceptual events and use this information to update motor plans, a skill that is crucial for language. However, the characteristics of the auditory system that enable this temporal precision are only beginning to be understood. Previous work has shown that participants who can tap consistently to a metronome have neural responses to sound with greater phase coherence from trial to trial. We hypothesized that this relationship is driven by a link between the updating of motor output by auditory feedback and neural precision. Moreover, we hypothesized that neural phase coherence at both fast time scales (reflecting subcortical processing) and slow time scales (reflecting cortical processing) would be linked to auditory-motor timing integration. To test these hypotheses, we asked participants to synchronize to a pacing stimulus, and then changed either the tempo or the timing of the stimulus to assess whether they could rapidly adapt. Participants who could rapidly and accurately resume synchronization had neural responses to sound with greater phase coherence. However, this precise timing was limited to the time scale of 10 ms (100 Hz) or faster; neural phase coherence at slower time scales was unrelated to performance on this task. Auditory-motor adaptation therefore specifically depends upon consistent auditory processing at fast, but not slow, time scales. PMID:26750313
Long-range properties of 1 S bottomonium states
NASA Astrophysics Data System (ADS)
Brambilla, Nora; Krein, Gastão; Tarrús Castellà, Jaume; Vairo, Antonio
2016-03-01
In the framework of weakly coupled potential nonrelativistic QCD, we derive, first, an analytical expression for the chromopolarizability of 1 S bottomonium states in agreement with previous determinations. Then we use the QCD trace anomaly to obtain the two-pion production amplitude for the chromopolarizability operator and match the result to a chiral effective field theory with 1 S bottomonium states and pions as degrees of freedom. In this chiral effective field theory we compute some long-range properties of the 1 S bottomonium generated by the pion coupling such as the leading chiral logarithm to the 1 S bottomonium mass and the van der Waals potential between two 1 S bottomonium states. Both results improve on previously known expressions.
Integrated real-time control of MHD instabilities using multi-beam ECRH/ECCD systems on TCV
NASA Astrophysics Data System (ADS)
Felici, F.; Goodman, T. P.; Sauter, O.; Canal, G.; Coda, S.; Duval, B. P.; Rossel, J. X.; the TCV Team
2012-07-01
Simultaneous real-time control of multiple MHD instabilities is experimentally demonstrated in the TCV tokamak. Multiple sources of EC heating and current drive, injected through real-time controlled launchers, are used to stabilize 3/2 and 2/1 neoclassical tearing modes (NTMs) rapidly after their appearance. Control of the sawtooth instability using a new sawtooth-pacing technique is demonstrated, providing precise control of the time of appearance of the sawtooth crash. Efficient NTM preemption can then be performed by applying pulsed power on the mode rational surface at the time of the seed-island generating sawtooth crash. These three elements are combined into one integrated control system which can simultaneously control the sawtooth period, preempt the formation of NTMs and suppress these if they appear.
NASA Astrophysics Data System (ADS)
Arai, Jun; Okano, Fumio; Hoshino, Haruo; Yuyama, Ichiro
1998-04-01
Because a three-dimensional (3-D) autostereoscopic image can be seen from a desired viewpoint without the aid of special viewing glasses, integral photography (IP) is an ideal way to create 3-D autostereoscopic images. We have already proposed a real-time IP method that offers 3-D autostereoscopic images of moving objects in real time by use of a microlens array and a high-definition television camera. But there are two problems yet to be resolved: One is pseudoscopic images that show a reversed depth representation. The other is interference between the element images that constitute a 3-D autostereoscopic image. We describe a new gradient-index lense-array method based on real-time IP to overcome these two problems. Experimental results indicating the advantages of this method are shown. These results suggest the possibility of using a gradient-index lens array for real-time IP.
Integrated Real-Time PCR for Detection and Monitoring of Legionella pneumophila in Water Systems▿
Yaradou, Diaraf Farba; Hallier-Soulier, Sylvie; Moreau, Sophie; Poty, Florence; Hillion, Yves; Reyrolle, Monique; André, Janine; Festoc, Gabriel; Delabre, Karine; Vandenesch, François; Etienne, Jerome; Jarraud, Sophie
2007-01-01
We evaluated a ready-to-use real-time quantitative Legionella pneumophila PCR assay system by testing 136 hot-water-system samples collected from 55 sites as well as 49 cooling tower samples collected from 20 different sites, in parallel with the standard culture method. The PCR assay was reproducible and suitable for routine quantification of L. pneumophila. An acceptable correlation between PCR and culture results was obtained for sanitary hot-water samples but not for cooling tower samples. We also monitored the same L. pneumophila-contaminated cooling tower for 13 months by analyzing 104 serial samples. The culture and PCR results were extremely variable over time, but the curves were similar. The differences between the PCR and culture results did not change over time and were not affected by regular biocide treatment. This ready-to-use PCR assay for L. pneumophila quantification could permit more timely disinfection of cooling towers. PMID:17194840
Kojima, Tsuyoshi; Valenzuela, Carla V.; Novaleski, Carolyn K.; Van Deusen, Mark; Mitchell, Joshua R.; Garrett, C. Gaelyn; Sivasankar, M. Preeti; Rousseau, Bernard
2014-01-01
Objective To investigate the effects of increasing time and magnitude doses of vibration exposure on transcription of the vocal fold's junctional proteins, structural alterations, and functional tissue outcomes. Study Design Animal study. Methods 100 New Zealand White breeder rabbits were studied. Dependent variables were measured in response to increasing time doses (30, 60, or 120 minutes) and magnitude doses (control, modal intensity, and raised intensity) of vibration exposure. Messenger RNA expression of occludin, zonula occluden-1 (ZO-1), E-cadherin, β-catenin, interleukin 1β (IL-1β), cyclooxygenase-2 (COX-2), transforming growth factor β-1 (TGFβ1), and fibronectin were measured. Tissue structural alterations were assessed using transmission electron microscopy (TEM). Transepithelial resistance was used to measure functional tissue outcomes. Results Occludin gene expression was downregulated in vocal folds exposed to 120 minute time doses of raised intensity phonation, relative to control, and modal intensity phonation. ZO-1 gene expression was upregulated following a 120 minute time dose of modal intensity phonation, compared to control, and downregulated after a 120 minute time dose of raised intensity phonation, compared to modal intensity phonation. E-cadherin gene expression was downregulated after a120 minute time dose of raised intensity phonation, compared to control and modal intensity phonation. TEM revealed extensive desquamation of the stratified squamous epithelial cells with increasing time and magnitude doses of vibration exposure. A general observation of lower transepithelial resistance measures was made in tissues exposed to raised intensity phonation, compared to all other groups. Conclusions This study provides evidence of vocal fold tissue responses to varying time and magnitude doses of vibration exposure. Level of Evidence N/A PMID:25073715
NASA Astrophysics Data System (ADS)
El-Haddad, Mohamed T.; Ehlers, Justis P.; Srivastava, Sunil K.; Tao, Yuankai K.
2015-03-01
Optical coherence tomography (OCT) allows high-resolution imaging of tissue microstructure and is the goldstandard for clinical ophthalmic diagnostics. Recent development of microscope-integrated intraoperative OCT (iOCT) systems has allowed cross-sectional imaging of surgical dynamics, but limitations in real-time visualization of instrument-tissue interactions remain the critical barrier for iOCT-guided ophthalmic surgery. Spatial compounding has been previously presented as a method for acquiring, processing, and visualizing cross-sectional iOCT images of surgical maneuvers. However, spatial compounding trades-off temporal resolution and FOV, which generally limits video-rate visualization to small regions at the tip of surgical instruments. To overcome these limitations, we present methods for automated dynamic surgical instrument tracking iOCT. B-scans are obtained along and orthogonal to the instrument axis and centered at the instrument tip at all times to allow cross-sectional visualization of ophthalmic surgical maneuvers for intraoperative guidance. Surgical instrument tracking has been previously demonstrated using different imaging modalities, including an OCT-integrated scanning probe. However, the latter uses large feature points, which are impractical in a surgical setting. Here, we describe automated stereo-vision instrument tracking, which achieves <250 μm accuracy, using tracking feature points that are easily integrated with ophthalmic surgical instruments. The instrument tracking system was integrated with an iOCT system to provide video-rate instrument tip tracked crosssectional B-scan imaging during ophthalmic surgical maneuvers, allowing visualization of tissue-instrument interactions and providing feedback on positioning, depth of penetration, and tissue compression in cadaveric porcine eyes. Real-time instrument tracked cross-sectional imaging can potentially help guide clinical decision-making during ophthalmic surgery.
Simulations as real-time integration of information: "Covalence", an Organic Chemistry game
NASA Astrophysics Data System (ADS)
Mathias, Jason
College-level Organic Chemistry classes can be overwhelming to their students. In addition to learning a relatively large amount of information, students have to learn to read multiple visual models and use them to understand subtle differences in the science. In making the puzzle game Covalence to address Organic Chemistry education, I decided to focus on three aspects of the subject's education -- Hidden information in the various visual models, the lack of integration of these representations into a 3D representation of Chemical phenomena, and an atom-based view of the molecules and how they contribute to the field's subtle issues. This paper discusses various traditional visual models taught in Organic Chemistry classes, devising a new visual model to bring out hidden information in these traditional models, and designing levels based on known reactions and their consequences, to illustrate Organic Chemistry's elegance and subtlety.
Neural Basis of the Time Window for Subjective Motor-Auditory Integration
Toida, Koichi; Ueno, Kanako; Shimada, Sotaro
2016-01-01
Temporal contiguity between an action and corresponding auditory feedback is crucial to the perception of self-generated sound. However, the neural mechanisms underlying motor–auditory temporal integration are unclear. Here, we conducted four experiments with an oddball paradigm to examine the specific event-related potentials (ERPs) elicited by delayed auditory feedback for a self-generated action. The first experiment confirmed that a pitch-deviant auditory stimulus elicits mismatch negativity (MMN) and P300, both when it is generated passively and by the participant’s action. In our second and third experiments, we investigated the ERP components elicited by delayed auditory feedback for a self-generated action. We found that delayed auditory feedback elicited an enhancement of P2 (enhanced-P2) and a N300 component, which were apparently different from the MMN and P300 components observed in the first experiment. We further investigated the sensitivity of the enhanced-P2 and N300 to delay length in our fourth experiment. Strikingly, the amplitude of the N300 increased as a function of the delay length. Additionally, the N300 amplitude was significantly correlated with the conscious detection of the delay (the 50% detection point was around 200 ms), and hence reduction in the feeling of authorship of the sound (the sense of agency). In contrast, the enhanced-P2 was most prominent in short-delay (≤200 ms) conditions and diminished in long-delay conditions. Our results suggest that different neural mechanisms are employed for the processing of temporally deviant and pitch-deviant auditory feedback. Additionally, the temporal window for subjective motor–auditory integration is likely about 200 ms, as indicated by these auditory ERP components. PMID:26779000
Integrated electronics for time-resolved array of single-photon avalanche diodes
NASA Astrophysics Data System (ADS)
Acconcia, G.; Crotti, M.; Rech, I.; Ghioni, M.
2013-12-01
The Time Correlated Single Photon Counting (TCSPC) technique has reached a prominent position among analytical methods employed in a great variety of fields, from medicine and biology (fluorescence spectroscopy) to telemetry (laser ranging) and communication (quantum cryptography). Nevertheless the development of TCSPC acquisition systems featuring both a high number of parallel channels and very high performance is still an open challenge: to satisfy the tight requirements set by the applications, a fully parallel acquisition system requires not only high efficiency single photon detectors but also a read-out electronics specifically designed to obtain the highest performance in conjunction with these sensors. To this aim three main blocks have been designed: a gigahertz bandwidth front-end stage to directly read the custom technology SPAD array avalanche current, a reconfigurable logic to route the detectors output signals to the acquisition chain and an array of time measurement circuits capable of recording the photon arrival times with picoseconds time resolution and a very high linearity. An innovative architecture based on these three circuits will feature a very high number of detectors to perform a truly parallel spatial or spectral analysis and a smaller number of high performance time-to-amplitude converter offering very high performance and a very high conversion frequency while limiting the area occupation and power dissipation. The routing logic will make the dynamic connection between the two arrays possible in order to guarantee that no information gets lost.
Jade-1S phosphorylation induced by CK1α contributes to cell cycle progression.
Borgal, Lori; Rinschen, Markus M; Dafinger, Claudia; Liebrecht, Valérie I; Abken, Hinrich; Benzing, Thomas; Schermer, Bernhard
2016-04-17
The PHD zinc finger protein Jade-1S is a component of the HBO1 histone acetyltransferase complex and binds chromatin in a cell cycle-dependent manner. Jade-1S also acts as an E3 ubiquitin ligase for the canonical Wnt effector protein β-catenin and is influenced by CK1α-mediated phosphorylation. To further elucidate the functional impact of this phosphorylation, we used a stable, low-level expression system to express either wild-type or mutant Jade-1S lacking the N-terminal CK1α phosphorylation motif. Interactome analyses revealed that the Jade-1S mutant unable to be phosphorylated by CK1α has an increased binding affinity to proteins involved in chromatin remodelling, histone deacetylation, transcriptional repression, and ribosome biogenesis. Interestingly, cells expressing the mutant displayed an elongated cell shape and a delay in cell cycle progression. Finally, phosphoproteomic analyses allowed identification of a Jade-1S site phosphorylated in the presence of CK1α but closely resembling a PLK1 phosphorylation motif. Our data suggest that Jade-1S phosphorylation at an N-terminal CK1α motif creates a PLK1 phospho-binding domain. We propose CK1α phosphorylation of Jade 1S to serve as a molecular switch, turning off chromatin remodelling functions of Jade-1S and allowing timely cell cycle progression. As Jade-1S protein expression in the kidney is altered upon renal injury, this could contribute to understanding mechanisms underlying epithelial injury repair. PMID:26919559
Accelerating Time Integration for the Shallow Water Equations on the Sphere Using GPUs
Archibald, R.; Evans, K. J.; Salinger, A.
2015-06-01
The push towards larger and larger computational platforms has made it possible for climate simulations to resolve climate dynamics across multiple spatial and temporal scales. This direction in climate simulation has created a strong need to develop scalable time-stepping methods capable of accelerating throughput on high performance computing. This work details the recent advances in the implementation of implicit time stepping on a spectral element cube-sphere grid using graphical processing units (GPU) based machines. We demonstrate how solvers in the Trilinos project are interfaced with ACME and GPU kernels can significantly increase computational speed of the residual calculations in themore » implicit time stepping method for the shallow water equations on the sphere. We show the optimization gains and data structure reorganization that facilitates the performance improvements.« less
Accelerating Time Integration for the Shallow Water Equations on the Sphere Using GPUs
Archibald, R.; Evans, K. J.; Salinger, A.
2015-06-01
The push towards larger and larger computational platforms has made it possible for climate simulations to resolve climate dynamics across multiple spatial and temporal scales. This direction in climate simulation has created a strong need to develop scalable time-stepping methods capable of accelerating throughput on high performance computing. This work details the recent advances in the implementation of implicit time stepping on a spectral element cube-sphere grid using graphical processing units (GPU) based machines. We demonstrate how solvers in the Trilinos project are interfaced with ACME and GPU kernels can significantly increase computational speed of the residual calculations in the implicit time stepping method for the shallow water equations on the sphere. We show the optimization gains and data structure reorganization that facilitates the performance improvements.
Enabling fast, stable and accurate peridynamic computations using multi-time-step integration
Lindsay, P.; Parks, M. L.; Prakash, A.
2016-04-13
Peridynamics is a nonlocal extension of classical continuum mechanics that is well-suited for solving problems with discontinuities such as cracks. This paper extends the peridynamic formulation to decompose a problem domain into a number of smaller overlapping subdomains and to enable the use of different time steps in different subdomains. This approach allows regions of interest to be isolated and solved at a small time step for increased accuracy while the rest of the problem domain can be solved at a larger time step for greater computational efficiency. Lastly, performance of the proposed method in terms of stability, accuracy, andmore » computational cost is examined and several numerical examples are presented to corroborate the findings.« less
1s2s2p2 5p3 5S transition in B ii
NASA Astrophysics Data System (ADS)
Mannervik, S.; Cederquist, H.; Martinson, I.; Brage, T.; Froese Fischer, C.
1987-04-01
An experimental and theoretical study has been made of the 1s2s2p2 5P-1s2p3 5S transition in B ii. The experimental wavelength and lifetime (1323.92+/-0.07 Å and 0.65+/-0.01 ns), determined by beam-foil spectroscopy, are more than five times more accurate than previous experimental results. Our theoretical data, from multiconfiguration Hartree-Fock calculations, 1311.6 Å and 0.601 ns, are in excellent agreement with previous theoretical predictions of Beck and Nicolaides [Phys. Lett. 61A, 227 (1977)]. We have also observed the 1s2p3 5S-1s2p23s 5P transition, at 857.7+/-0.2 Å, in accord with the theoretical value 859.1 Å.
NASA Astrophysics Data System (ADS)
Makri, Nancy
2014-10-01
The real-time path integral representation of the reduced density matrix for a discrete system in contact with a dissipative medium is rewritten in terms of the number of blips, i.e., elementary time intervals over which the forward and backward paths are not identical. For a given set of blips, it is shown that the path sum with respect to the coordinates of all remaining time points is isomorphic to that for the wavefunction of a system subject to an external driving term and thus can be summed by an inexpensive iterative procedure. This exact decomposition reduces the number of terms by a factor that increases exponentially with propagation time. Further, under conditions (moderately high temperature and/or dissipation strength) that lead primarily to incoherent dynamics, the "fully incoherent limit" zero-blip term of the series provides a reasonable approximation to the dynamics, and the blip series converges rapidly to the exact result. Retention of only the blips required for satisfactory convergence leads to speedup of full-memory path integral calculations by many orders of magnitude.
Makri, Nancy
2014-10-07
The real-time path integral representation of the reduced density matrix for a discrete system in contact with a dissipative medium is rewritten in terms of the number of blips, i.e., elementary time intervals over which the forward and backward paths are not identical. For a given set of blips, it is shown that the path sum with respect to the coordinates of all remaining time points is isomorphic to that for the wavefunction of a system subject to an external driving term and thus can be summed by an inexpensive iterative procedure. This exact decomposition reduces the number of terms by a factor that increases exponentially with propagation time. Further, under conditions (moderately high temperature and/or dissipation strength) that lead primarily to incoherent dynamics, the “fully incoherent limit” zero-blip term of the series provides a reasonable approximation to the dynamics, and the blip series converges rapidly to the exact result. Retention of only the blips required for satisfactory convergence leads to speedup of full-memory path integral calculations by many orders of magnitude.
H. Qin and X. Guan
2008-02-11
A variational symplectic integrator for the guiding-center motion of charged particles in general magnetic fields is developed for long-time simulation studies of magnetized plasmas. Instead of discretizing the differential equations of the guiding-center motion, the action of the guiding-center motion is discretized and minimized to obtain the iteration rules for advancing the dynamics. The variational symplectic integrator conserves exactly a discrete Lagrangian symplectic structure, and has better numerical properties over long integration time, compared with standard integrators, such as the standard and variable time-step fourth order Runge-Kutta methods.
Qin, Hong; Guan, Xiaoyin
2008-01-25
A variational symplectic integrator for the guiding-center motion of charged particles in general magnetic fields is developed for long-time simulation studies of magnetized plasmas. Instead of discretizing the differential equations of the guiding-center motion, the action of the guiding-center motion is discretized and minimized to obtain the iteration rules for advancing the dynamics. The variational symplectic integrator conserves exactly a discrete Lagrangian symplectic structure, and has better numerical properties over long integration time, compared with standard integrators, such as the standard and variable time-step fourth order Runge-Kutta methods. PMID:18232993
Minesaki, Yukitaka
2013-08-01
For the restricted three-body problem, we propose an accurate orbital integration scheme that retains all conserved quantities of the two-body problem with two primaries and approximately preserves the Jacobi integral. The scheme is obtained by taking the limit as mass approaches zero in the discrete-time general three-body problem. For a long time interval, the proposed scheme precisely reproduces various periodic orbits that cannot be accurately computed by other generic integrators.
Sander, A.; Schmelzle, R.; Murray, J.C.; Scherpbier-Heddema, T.; Buetow, K.H.; Weissenbach, J.; Ludwig, K.; Zingg, M.
1995-01-01
Van der Woude syndrome (VWS) is an autosomal dominant craniofacial disorder characterized by lip pits, clefting of the primary or secondary palate, and hypodontia. The gene has been localized, by RFLP-based linkage studies, to region 1q32-41 between D1S65-REN and D1S65-TGFB2. In this study we report the linkage analysis of 15 VWS families, using 18 microsatellite markers. Multipoint linkage analysis places the gene, with significant odds of 2,344:1, in a 4.1-cM interval flanked by D1S245 and D1S414. Two-point linkage analysis demonstrates close linkage of VWS with D1S205 (lod score [Z] = 24.41 at {theta} = .00) and with D1S491 (Z = 21.23 at {theta} = .00). The results revise the previous assignment of the VWS locus and show in an integrated map of the region 1q32-42 that the VWS gene resides more distally than previously suggested. When information about heterozygosity of the closely linked marker D1S491 in the affected members of the VWS family with a microdeletion is taken into account, the VWS critical region can be further narrowed, to the 3.6-cM interval between D1S491 and D1S414. 38 refs., 3 figs., 2 tabs.
AN "INJURY-TIME INTEGRAL" MODEL FOR RELATING ACUTE TO CHRONIC INJURY TO PHOSGENE
ABSTRACT
The present study compares acute and subchronic episodic exposures to phosgene to test the applicability of the "concentration x time" (C x T) product as a measure of exposure dose, and to relate acute toxicity and adaptive responses to chronic toxicity. Rats (m...
Integrating Evidence-Based Practice into a Therapeutic Exercise Course: Real-Time Patient Experience
ERIC Educational Resources Information Center
Popp, Jennifer K.
2014-01-01
Athletic training students need real-time patient experiences in order to transfer the knowledge and skills learned in the classroom into clinical practice. The objective is to present a description of an assignment that could be incorporated into a therapeutic exercise course giving the student an opportunity to evaluate a patient, design a…
Integrated payload and mission planning, phase 3. Volume 3: Ground real-time mission operations
NASA Technical Reports Server (NTRS)
White, W. J.
1977-01-01
The payloads tentatively planned to fly on the first two Spacelab missions were analyzed to examine the cost relationships of providing mission operations support from onboard vs the ground-based Payload Operations Control Center (POCC). The quantitative results indicate that use of a POCC, with data processing capability, to support real-time mission operations is the most cost effective case.
Time-integrated measurements of $\\gamma$ at the Tevatron and prospects
Squillacioti, Paola
2010-12-01
The measurement of CP-violating asymmetries and branching ratios of B {yields} DK modes allows a theoretically-clean extraction of the CKM angle {gamma}. We report recent CDF measurements with Cabibbo suppressed ({pi}{pi}, KK) or doubly Cabibbo suppressed (K{sup +}{pi}{sup -}) D decays. These measurements are performed for the first time in hadron collisions.
ERIC Educational Resources Information Center
Goomas, David
2015-01-01
Numerous studies have reported on the innovative and effective delivery of online course content by community colleges, but not much has been done on how learning management systems (LMS) can deliver real-time (immediate data delivery) antecedents that inform students of performance requirements. This pilot study used Blackboard's™…
ERIC Educational Resources Information Center
Fazio, C.; Guastella, I.; Tarantino, G.
2007-01-01
In this paper, we describe a pedagogical approach to elastic body movement based on measurements of the contact times between a metallic rod and small bodies colliding with it and on modelling of the experimental results by using a microcomputer-based laboratory and simulation tools. The experiments and modelling activities have been built in the…
ERIC Educational Resources Information Center
Southard, Jonathan N.
2014-01-01
Instrumentation for real-time PCR is used primarily for amplification and quantitation of nucleic acids. The capability to measure fluorescence while controlling temperature in multiple samples can also be applied to the analysis of proteins. Conformational stability and changes in stability due to ligand binding are easily assessed. Protein…
Chen, Guangye; Chacon, Luis; Knoll, Dana Alan; Barnes, Daniel C
2015-07-31
A multi-rate PIC formulation was developed that employs large timesteps for slow field evolution, and small (adaptive) timesteps for particle orbit integrations. Implementation is based on a JFNK solver with nonlinear elimination and moment preconditioning. The approach is free of numerical instabilities (ω_{pe}Δt >>1, and Δx >> λ_{D}), and requires many fewer dofs (vs. explicit PIC) for comparable accuracy in challenging problems. Significant gains (vs. conventional explicit PIC) may be possible for large scale simulations. The paper is organized as follows: Vlasov-Maxwell Particle-in-cell (PIC) methods for plasmas; Explicit, semi-implicit, and implicit time integrations; Implicit PIC formulation (Jacobian-Free Newton-Krylov (JFNK) with nonlinear elimination allows different treatments of disparate scales, discrete conservation properties (energy, charge, canonical momentum, etc.)); Some numerical examples; and Summary.
Lax representations and integrable time discretizations of the DDKdV, DDmKdV, and DDHOKdV
NASA Astrophysics Data System (ADS)
Zhu, Zuonong; Huang, Hongci; Xue, Weimin
1999-02-01
From a proper 2 × 2 discrete isospectral problem, a new differential-difference integrable equation in Lax sense is proposed by a discrete zero curvature equation. The DDKdV (differential-difference DdV equation) proposed by Ohta and Hirota and DDCDGKS (DD Caudrey-Dodd-Gibbon-Kotera-Sawada equation) are rederived. Some other new discrete KdV equations, discrete mKdV equations and discrete high order KdV equations which converge to the corresponding continuous soliton equations in the continuum limit are obtained. Integrable time discretizations of the DDKdV, DDmKdV (differential-difference mKdV equation) and DDHOKdV (differential-difference high order KdV equations) are given.
NASA Astrophysics Data System (ADS)
Wei, Qing-Lai; Song, Rui-Zhuo; Sun, Qiu-Ye; Xiao, Wen-Dong
2015-09-01
This paper estimates an off-policy integral reinforcement learning (IRL) algorithm to obtain the optimal tracking control of unknown chaotic systems. Off-policy IRL can learn the solution of the HJB equation from the system data generated by an arbitrary control. Moreover, off-policy IRL can be regarded as a direct learning method, which avoids the identification of system dynamics. In this paper, the performance index function is first given based on the system tracking error and control error. For solving the Hamilton-Jacobi-Bellman (HJB) equation, an off-policy IRL algorithm is proposed. It is proven that the iterative control makes the tracking error system asymptotically stable, and the iterative performance index function is convergent. Simulation study demonstrates the effectiveness of the developed tracking control method. Project supported by the National Natural Science Foundation of China (Grant Nos. 61304079 and 61374105), the Beijing Natural Science Foundation, China (Grant Nos. 4132078 and 4143065), the China Postdoctoral Science Foundation (Grant No. 2013M530527), the Fundamental Research Funds for the Central Universities, China (Grant No. FRF-TP-14-119A2), and the Open Research Project from State Key Laboratory of Management and Control for Complex Systems, China (Grant No. 20150104).
Increasing storage time of extended boar semen reduces sperm DNA integrity.
Boe-Hansen, Gry B; Ersbøll, Annette K; Greve, Torben; Christensen, Preben
2005-04-15
There is an extensive use of artificial insemination (AI) in the pig industry. Extended liquid boar semen may be used for insemination for up to 5 days after collection. The objective of this study was to determine the changes in sperm quality, when boar semen was extended and stored at 18 degrees C for up to 72 h post-collection. The study included three ejaculates from five boars, for each of the four breeds: Duroc, Hampshire, Landrace and Danish Large White (n=60 ejaculates). The sperm chromatin structure assay (SCSA) showed an increase in DNA fragmentation index (DFI) after 72 h of incubation (P<0.001), with no differences between breeds (P=0.07). For two Hampshire boars, all ejaculates had a large increase in DFI after 24 h of incubation. The standard deviation of DFI (SD-DFI) differed between breeds, with the SD-DFI for Hampshire being significantly greater than for the other breeds. The SD-DFI did not change during the 72 h of storage. Sperm viability was determined using SYBR-14 and propidium iodide in combination with flow cytometry. The sperm viability did not differ between breeds (P=0.21), but a difference in viability during storage (P<0.001) was detected. In conclusion, the SCSA cytogram patterns were consistent for different ejaculates within boars and storage of extended boar semen at 18 degrees C for 72 h significantly decreased the integrity of sperm DNA. PMID:15823356
NASA Astrophysics Data System (ADS)
Pilone, D.; Quinn, P.; Mitchell, A. E.; Baynes, K.; Shum, D.
2014-12-01
This talk introduces the audience to some of the very real challenges associated with visualizing data from disparate data sources as encountered during the development of real world applications. In addition to the fundamental challenges of dealing with the data and imagery, this talk discusses usability problems encountered while trying to provide interactive and user-friendly visualization tools. At the end of this talk the audience will be aware of some of the pitfalls of data visualization along with tools and techniques to help mitigate them. There are many sources of variable resolution visualizations of science data available to application developers including NASA's Global Imagery Browse Services (GIBS), however integrating and leveraging visualizations in modern applications faces a number of challenges, including: - Varying visualized Earth "tile sizes" resulting in challenges merging disparate sources - Multiple visualization frameworks and toolkits with varying strengths and weaknesses - Global composite imagery vs. imagery matching EOSDIS granule distribution - Challenges visualizing geographically overlapping data with different temporal bounds - User interaction with overlapping or collocated data - Complex data boundaries and shapes combined with multi-orbit data and polar projections - Discovering the availability of visualizations and the specific parameters, color palettes, and configurations used to produce them In addition to discussing the challenges and approaches involved in visualizing disparate data, we will discuss solutions and components we'll be making available as open source to encourage reuse and accelerate application development.
Is It Time To Consider Global Sharing of Integral Physics Data?
Harold F. McFarlane
2005-10-01
The innocent days of the Atoms for Peace program vanished with the suicide attack on the World Trade Center in New York City that occurred while the GLOBAL 2001 international nuclear fuel cycle conference was convened in Paris. Today’s reality is that maintaining an inventory of unirradiated highly enriched uranium or plutonium for critical experiments requires a facility to accept substantial security cost and intrusion. In the context of a large collection of benchmark integral experiments collected over several decades and the ongoing rapid advances in computer modeling and simulation, there seems to be ample incentive to reduce both the number of facilities and material inventory quantities worldwide. As a result of ongoing nonproliferation initiatives, there are viable programs that will accept highly enriched uranium for down blending into commercial fuel. Nevertheless, there are formidable hurdles to overcome before national institutions will voluntarily give up existing nuclear research capabilities. GLOBAL 2005 was the appropriate forum to begin fostering a new spirit of cooperation that could lead to improved international security and better use of precious research and development resources, while ensuring access to existing and future critical experiment data.
Chobhthaigh, Sorcha Ni; Wilson, Charlotte
2015-09-01
The current study investigated 4- to 8-year-olds' (N = 81) understanding of embarrassment and their ability to integrate temporal and mental state information to predict and explain emotions. Participants heard stories describing characters commit trivial social transgressions, and then the next day, characters found themselves in the same situation that led to the previous transgression. For some story endings, participants were asked to predict and explain how the character felt, and for others, participants were told the character started to feel embarrassed and they were asked to explain why. Participants' responses were coded and analysed using nonparametric statistical tests. Kruskal-Wallis analyses revealed significant developments occur between 6 and 8 years in children's understanding of embarrassment and their ability to explain individual's emotion as caused by anticipating the reoccurrence of a previous embarrassing event. Younger children demonstrated a basic knowledge of embarrassment but failed to demonstrate more advanced understanding of the emotion. Findings from the current study indicate children reach a more mature understanding of embarrassment and the implications of committing social transgressions between 7 and 8 years. Finally, the current study contributes to the literature on children's ability to infer mental states and temporally connect experiences. PMID:26033237
NASA Technical Reports Server (NTRS)
1977-01-01
The 20x9 TDI array was developed to meet the LANDSAT Thematic Mapper Requirements. This array is based upon a self-aligned, transparent gate, buried channel process. The process features: (1) buried channel, four phase, overlapping gate CCD's for high transfer efficiency without fat zero; (2) self-aligned transistors to minimize clock feedthrough and parasitic capacitance; and (3) transparent tin oxide electrode for high quantum efficiency with front surface irradiation. The requirements placed on the array and the performance achieved are summarized. This data is the result of flat field measurements only, no imaging or dynamic target measurements were made during this program. Measurements were performed with two different test stands. The bench test equipment fabricated for this program operated at the 8 micro sec line time and employed simple sampling of the gated MOSFET output video signal. The second stand employed Correlated Doubled Sampling (CDS) and operated at 79.2 micro sec line time.
Analyzing integrated circuits at work with a picosecond time-gated imager.
Comelli, D; D'Andrea, C; Valentini, G; Cubeddu, R; Casiraghi, R; Cantarelli, D
2005-12-12
A system based on a picosecond time-gated image intensifier is proposed for non-contact testing of CMOS circuits. The apparatus allows one to record the temporal evolution of the luminescence emitted during transistor switching as a function of the position inside the chip. The system is characterized by an intrinsic parallelism in the spatial dimensions. This feature is noticeable for studying wide sections of complex circuits, like microprocessors and random access memories, where multiple electrical events occur simultaneously. Experiments on a CMOS inverter chain and on a static memory have been carried out, in order to demonstrate the applicability of a picosecond time-gated imager to circuit analysis. PMID:19503220
Integrating impairments in reaction time and executive function using a diffusion model framework.
Karalunas, Sarah L; Huang-Pollock, Cynthia L
2013-07-01
Using Ratcliff's diffusion model and ex-Gaussian decomposition, we directly evaluate the role individual differences in reaction time (RT) distribution components play in the prediction of inhibitory control and working memory (WM) capacity in children with and without ADHD. Children with (n = 91, [Formula: see text] age = 10.2 years, 67 % male) and without ADHD (n = 62, [Formula: see text] age = 10.6 years, 46 % male) completed four tasks of WM and a stop signal reaction time (SSRT) task. Children with ADHD had smaller WM capacities and less efficient inhibitory control. Diffusion model analyses revealed that children with ADHD had slower drift rates (v) and faster non-decision times (Ter), but there were no group differences in boundary separations (a). Similarly, using an ex-Gaussian approach, children with ADHD had larger τ values than non-ADHD controls, but did not differ in μ or σ distribution components. Drift rate mediated the association between ADHD status and performance on both inhibitory control and WM capacity. τ also mediated the ADHD-executive function impairment associations; however, models were a poorer fit to the data. Impaired performance on RT and executive functioning tasks has long been associated with childhood ADHD. Both are believed to be important cognitive mechanisms to the disorder. We demonstrate here that drift rate, or the speed at which information accumulates towards a decision, is able to explain both. PMID:23334775
Real-Time Monitoring System Using Unmanned Aerial Vehicle Integrated with Sensor Observation Service
NASA Astrophysics Data System (ADS)
Witayangkurn, A.; Nagai, M.; Honda, K.; Dailey, M.; Shibasaki, R.
2011-09-01
The Unmanned Aerial Vehicle (UAV) is an emerging technology being adapted for a wide range of applications. Real-time monitoring is essential to enhance the effectiveness of UAV applications. Sensor networks are networks constructed from various sensor nodes. International standard such as OGC's SOS (Sensor Observation Service) makes it possible to share sensor data with other systems as well as to provide accessibility to globally distributed users. In this paper, we propose a system combining UAV technology and sensor network technology to use an UAV as a mobile node of sensor network so that the sensor data from UAV is published and shared real-time. A UAV can extend the observation range of a sensor network to remote areas where it is usually difficult to access such as disaster area. We constructed a UAV system using remote-controlled helicopter and various sensors such as GPS, gyrocompass, laser range finder, Digital camera and Thermometer. Furthermore, we extended the Sensor Observation Service (SOS) and Sensor Service Grid (SSG) to support mobile sensor nodes. Then, we conducted experiments of flying the helicopter over an area of the interest. During the flight, the system measured environmental data using its sensors and captured images of the ground. The data was sent to a SOS node as the ground station via Wi-Fi which was published using SSG to give real- time access to globally distributed users.
Integrating impairments in reaction time and executive function using a diffusion model framework
Karalunas, Sarah L.; Huang-Pollock, Cynthia L.
2013-01-01
Using Ratcliff’s diffusion model and ex-Gaussian decomposition, we directly evaluate the role individual differences in reaction time (RT) distribution components play in the prediction of inhibitory control and working memory (WM) capacity in children with and without ADHD. Children with (n=92, x̄ age= 10.2 years, 67% male) and without ADHD (n=62, x̄ age=10.6 years, 46% male) completed four tasks of WM and a stop signal reaction time (SSRT) task. Children with ADHD had smaller WM capacities and less efficient inhibitory control. Diffusion model analyses revealed that children with ADHD had slower drift rates (v) and faster non-decision times (Ter), but there were no group differences in boundary separations (a). Similarly, using an ex-Gaussian approach, children with ADHD had larger τ values than non-ADHD controls, but did not differ in µ or σ distribution components. Drift rate mediated the association between ADHD status and performance on both inhibitory control and WM capacity. τ also mediated the ADHD-executive function impairment associations; however, models were a poorer fit to the data. Impaired performance on RT and executive functioning tasks has long been associated with childhood ADHD. Both are believed to be important cognitive mechanisms to the disorder. We demonstrate here that drift rate, or the speed at which information accumulates towards a decision, is able to explain both. PMID:23334775
Neural network training by integration of adjoint systems of equations forward in time
NASA Technical Reports Server (NTRS)
Toomarian, Nikzad (Inventor); Barhen, Jacob (Inventor)
1992-01-01
A method and apparatus for supervised neural learning of time dependent trajectories exploits the concepts of adjoint operators to enable computation of the gradient of an objective functional with respect to the various parameters of the network architecture in a highly efficient manner. Specifically, it combines the advantage of dramatic reductions in computational complexity inherent in adjoint methods with the ability to solve two adjoint systems of equations together forward in time. Not only is a large amount of computation and storage saved, but the handling of real-time applications becomes also possible. The invention has been applied it to two examples of representative complexity which have recently been analyzed in the open literature and demonstrated that a circular trajectory can be learned in approximately 200 iterations compared to the 12000 reported in the literature. A figure eight trajectory was achieved in under 500 iterations compared to 20000 previously required. The trajectories computed using our new method are much closer to the target trajectories than was reported in previous studies.
Neural Network Training by Integration of Adjoint Systems of Equations Forward in Time
NASA Technical Reports Server (NTRS)
Toomarian, Nikzad (Inventor); Barhen, Jacob (Inventor)
1999-01-01
A method and apparatus for supervised neural learning of time dependent trajectories exploits the concepts of adjoint operators to enable computation of the gradient of an objective functional with respect to the various parameters of the network architecture in a highly efficient manner. Specifically. it combines the advantage of dramatic reductions in computational complexity inherent in adjoint methods with the ability to solve two adjoint systems of equations together forward in time. Not only is a large amount of computation and storage saved. but the handling of real-time applications becomes also possible. The invention has been applied it to two examples of representative complexity which have recently been analyzed in the open literature and demonstrated that a circular trajectory can be learned in approximately 200 iterations compared to the 12000 reported in the literature. A figure eight trajectory was achieved in under 500 iterations compared to 20000 previously required. Tbc trajectories computed using our new method are much closer to the target trajectories than was reported in previous studies.
Tang, Sanyi; Tang, Guangyao; Cheke, Robert A
2010-05-21
Many factors including pest natural enemy ratios, starting densities, timings of natural enemy releases, dosages and timings of insecticide applications and instantaneous killing rates of pesticides on both pests and natural enemies can affect the success of IPM control programmes. To address how such factors influence successful pest control, hybrid impulsive pest-natural enemy models with different frequencies of pesticide sprays and natural enemy releases were proposed and analyzed. With releasing both more or less frequent than the sprays, a stability threshold condition for a pest eradication periodic solution is provided. Moreover, the effects of times of spraying pesticides (or releasing natural enemies) and control tactics on the threshold condition were investigated with regard to the extent of depression or resurgence resulting from pulses of pesticide applications. Multiple attractors from which the pest population oscillates with different amplitudes can coexist for a wide range of parameters and the switch-like transitions among these attractors showed that varying dosages and frequencies of insecticide applications and the numbers of natural enemies released are crucial. To see how the pesticide applications could be reduced, we developed a model involving periodic releases of natural enemies with chemical control applied only when the densities of the pest reached the given Economic Threshold. The results indicate that the pest outbreak period or frequency largely depends on the initial densities and the control tactics. PMID:20219475
ABSOLUTE TIMING OF THE CRAB PULSAR WITH THE INTEGRAL/SPI TELESCOPE
Molkov, S.; Jourdain, E.; Roques, J. P.
2010-01-01
We have investigated the pulse shape evolution of the Crab pulsar emission in the hard X-ray domain of the electromagnetic spectrum. In particular, we have studied the alignment of the Crab pulsar phase profiles measured in the hard X-rays and in other wavebands. To obtain the hard X-ray pulse profiles, we have used six years (2003-2009, with a total exposure of about 4 Ms) of publicly available data of the SPI telescope on-board the International Gamma-Ray Astrophysics Laboratory observatory, folded with the pulsar time solution derived from the Jodrell Bank Crab Pulsar Monthly Ephemeris. We found that the main pulse in the hard X-ray 20-100 keV energy band leads the radio one by 8.18 +- 0.46 milliperiods in phase, or 275 +- 15 mus in time. Quoted errors represent only statistical uncertainties. Our systematic error is estimated to be approx40 mus and is mainly caused by the radio measurement uncertainties. In hard X-rays, the average distance between the main pulse and interpulse on the phase plane is 0.3989 +- 0.0009. To compare our findings in hard X-rays with the soft 2-20 keV X-ray band, we have used data of quasi-simultaneous Crab observations with the proportional counter array monitor on-board the Rossi X-Ray Timing Explorer mission. The time lag and the pulses separation values measured in the 3-20 keV band are 0.00933 +- 0.00016 (corresponding to 310 +- 6 mus) and 0.40016 +- 0.00028 parts of the cycle, respectively. While the pulse separation values measured in soft X-rays and hard X-rays agree, the time lags are statistically different. Additional analysis show that the delay between the radio and X-ray signals varies with energy in the 2-300 keV energy range. We explain such a behavior as due to the superposition of two independent components responsible for the Crab pulsed emission in this energy band.