Science.gov

Sample records for iv large time

  1. Consistency of IVS nutation time series

    NASA Astrophysics Data System (ADS)

    Gattano, César; Lambert, Sébastien; Bizouard, Christian

    2016-04-01

    We give a review of the various VLBI-derived nutation time series provided by the different operational analysis centers of the IVS and three combination centers (IVS, IERS EOP Center, and Rapid Service/Prediction Center). We focus on the stability of small nutation amplitudes, including the free core nutation and other atmospherically-driven nutations, that are of interest for improving Earth models. We discuss the possible origins of the differences (software packaged, inversion methods, analysis configuration including a priori and estimation strategy) and the consequences for scientific exploitation of the data, especially in terms of nutation modeling and inference of the Earth's internal structure.

  2. Large excitonic effects in group-IV sulfide monolayers

    NASA Astrophysics Data System (ADS)

    Tuttle, Blair R.; Alhassan, Saeed M.; Pantelides, Sokrates T.

    2015-12-01

    Large exciton binding energies are a distinguishing feature of two-dimensional semiconductors because of reduced screening, potentially leading to unique optoelectronic applications. Here we use electronic structure methods to calculate the properties of a two-dimensional material class: group-IV monosulfides including SiS, GeS, and SnS. Bulk SiS is predicted to be a metastable layered material. Quasiparticle excitations are calculated with the G0W0 method and the Bethe-Salpeter equation is are used to include electron-hole interactions. For monolayers, strongly bound excitons are found below the quasiparticle absorption edge. The predicted excitonic binding energies are as high as 0.7 eV. Due to large excitonic effects, these group-IV sulfide monolayers have great potential for nanoscale optoelectronic applications.

  3. Restoration of a large class IV fracture using direct composite resin: A clinical report.

    PubMed

    Romero, Mario F; Austin Grant, Jamie; Todd, Megan

    2017-04-03

    Restoration of anterior tooth fractures is a common dental procedure. Both direct and indirect options are clinically acceptable to repair fractured teeth. For a large class IV fracture, treatment planning is time consuming, and the artistic skills necessary to achieve optimal results can be daunting. This clinical report describes a step-by-step protocol for achieving highly esthetic direct anterior restorations.

  4. AB 1725, IV: Part-Time Faculty.

    ERIC Educational Resources Information Center

    California Community Colleges, Sacramento. Board of Governors.

    An overview is provided of issues related to the use of part-time faculty in community colleges in California and elsewhere in the nation. First, background information is provided on the major relevant issues. This section: (1) lists the teaching functions which are best carried out by full-time instructors as argued by those who favor employing…

  5. Time in Physics IV: Aristotle's reductionistic vision in four movements

    NASA Astrophysics Data System (ADS)

    Roark, Anthony Phillip

    Aristotle's definition of time in Physics IV.11 as ``a number of motion with respect to the before and after'' is often claimed to be viciously circular, since it is thought that `before' and `after' are terms that cannot be explicated independently of temporal concepts. My project in this dissertation is to defend Aristotle's theory against this charge of circularity and, further, to argue that it succeeds where some modern theories of time fail. The centerpiece of my interpretation is an explication of theoretical entities that Aristotle calls `the before and after in motion', entities that I have dubbed `kinetic positions'. Kinetic positions are instantaneous happenings within a movement that can be specified as functions of a moving object's actual spatial location and the telos, or end, of the movement. On Aristotle's view, time is an aspect of motion, and kinetic positions are the lower-level metaphysical counterparts of instants. It is in this sense that Aristotle's account is reductionistic: time derives its existence and structure from that of motion, and motion derives its existence and structure from that of spatial magnitudes. The success of my project requires that I: (i)establish that Aristotle's kinetic theory can be explicated independently of temporal concepts; (ii)explain how the asymmetrically-ordered kinetic continuum derives from the symmetrically-ordered spatial continuum; (iii)show that my interpretation of kinetic positions is consistent with Aristotle's claim in Physics VI that motion in an instant is impossible; (iv)explain the significance of Aristotle's placement of time within the genus number; (v)justify Aristotle's claim in IV.14 that time would not exist if there were no perceptive souls; (vi)how that Aristotle's account integrates temporal passage, the ``flow'' of time, in such a way as to be immune from devastating arguments, devised by McTaggart and others, against its possibility. I conclude that Aristotle ultimately conceives

  6. Large numbers hypothesis. IV - The cosmological constant and quantum physics

    NASA Technical Reports Server (NTRS)

    Adams, P. J.

    1983-01-01

    In standard physics quantum field theory is based on a flat vacuum space-time. This quantum field theory predicts a nonzero cosmological constant. Hence the gravitational field equations do not admit a flat vacuum space-time. This dilemma is resolved using the units covariant gravitational field equations. This paper shows that the field equations admit a flat vacuum space-time with nonzero cosmological constant if and only if the canonical LNH is valid. This allows an interpretation of the LNH phenomena in terms of a time-dependent vacuum state. If this is correct then the cosmological constant must be positive.

  7. Large numbers hypothesis. IV - The cosmological constant and quantum physics

    NASA Technical Reports Server (NTRS)

    Adams, P. J.

    1983-01-01

    In standard physics quantum field theory is based on a flat vacuum space-time. This quantum field theory predicts a nonzero cosmological constant. Hence the gravitational field equations do not admit a flat vacuum space-time. This dilemma is resolved using the units covariant gravitational field equations. This paper shows that the field equations admit a flat vacuum space-time with nonzero cosmological constant if and only if the canonical LNH is valid. This allows an interpretation of the LNH phenomena in terms of a time-dependent vacuum state. If this is correct then the cosmological constant must be positive.

  8. STT Doubles with Large DM - Part IV: Ophiuchus and Hercules

    NASA Astrophysics Data System (ADS)

    Knapp, Wilfried; Nanson, John

    2016-04-01

    The results of visual double star observing sessions suggested a pattern for STT doubles with large DM of being harder to resolve than would be expected based on the WDS catalog data. It was felt this might be a problem with expectations on one hand, and on the other might be an indication of a need for new precise measurements, so we decided to take a closer look at a selected sample of STT doubles and do some research. We found that like in the other constellations covered so far (Gem, Leo, UMa, etc.) at least several of the selected objects in Ophiuchus and Hercules show parameters quite different from the current WDS data.

  9. OSIRIS Large Guaranteed Time Programs

    NASA Astrophysics Data System (ADS)

    Cepa, J.; Bongiovanni, A.; Ramón-Pérez, M.; Pérez García, A. M.; Alfaro, E. J.; Castaneda, H. O.; Cervino, M.; Gallego, J.; González, J. J.; González-Serrano, J. I.; Lara-López, M. A.; Pérez-Martínez, R.; Pintos-Castro, I.; Sánchez-Portal, M.; Bland-Hawthorn, J.; Jones, D. H.

    2017-03-01

    The status of OTELO and Lockman SpReSO surveys, the two large guaranteed time programs currently under way using OSIRIS at the 10.4m GTC is presented. The OTELO project, designed to detect the main optical emission lines from Hα to Lyα at redshifts from 0.4 through 7, is the deepest emission line survey to date, with unprecedented sensitivity in the detection of small equivalent widths. Lockman SpReSO is aimed to obtaining optical spectra, up to 24.5 AB magnitudes, in the central 24×24 square arcminutes of the Lockman Hole field, which has been observed with ROSAT and XMM–Newton at the highest depth. Lockman SpReSO mainly targets Far Infrared sources detected with the Herschel Space Observatory.

  10. Combination Chemo, Rituximab, and Bevacizumab in Older Patients With Stage II-IV Diffuse Large B-Cell Lymphoma

    ClinicalTrials.gov

    2014-05-06

    Contiguous Stage II Adult Diffuse Large Cell Lymphoma; Noncontiguous Stage II Adult Diffuse Large Cell Lymphoma; Stage III Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma

  11. JPL pulsar timing observations. IV - Excess phase noise

    NASA Technical Reports Server (NTRS)

    Downs, G. S.; Krause-Polstorff, J.

    1986-01-01

    Previously published tables of geocentric arrival times for 24 pulsars covering a 12 year span are extended here to 14.5 years. The list of pulsars is extended by nine, most of which were observed for about 4 years. Known positins of these new objects are confirmed, and limits on the proper motions are obtained. Large phase excursions in PSR 0525 + 21 are found. The orbital parameters of the binary pulsar 0820 + 02 are tentatively confirmed. Short-term timing noise in excess of that expected from receiver considerations alone is established. Variations in the timing residuals for the original 24 pulsars are analyzed for correlations with other observable parameters. Little significant correlation with changes in pulse shape or energy or with the drift correction is found on time scales of 500 pulses or longer.

  12. Simple, Fast and Effective Correction for Irradiance Spatial Nonuniformity in Measurement of IVs of Large Area Cells at NREL

    SciTech Connect

    Moriarty, Tom

    2016-11-21

    The NREL cell measurement lab measures the IV parameters of cells of multiple sizes and configurations. A large contributing factor to errors and uncertainty in Jsc, Imax, Pmax and efficiency can be the irradiance spatial nonuniformity. Correcting for this nonuniformity through its precise and frequent measurement can be very time consuming. This paper explains a simple, fast and effective method based on bicubic interpolation for determining and correcting for spatial nonuniformity and verification of the method's efficacy.

  13. Time-dependent models of magnetic stars. IV - Perpendicular axes

    NASA Astrophysics Data System (ADS)

    Moss, David

    1987-05-01

    The evolution of large-scale initially axisymmetric fields immersed in middle main-sequence stellar models is followed in the case where the rotation axis and initial field axis are strictly perpendicular. The prediction that in this case the surface flux is never buried by the modified Eddington-Sweet circulation is verified, although mode-mixing may eventually reduce the strength of the dipolar field component. It appears that non-axisymmetric field components will grow over time-scales of 108yr or so. Effects of differing initial field geometries are discussed.

  14. Rates of DSM-IV psychiatric disorders among adolescents in a large metropolitan area.

    PubMed

    Roberts, Robert E; Roberts, Catherine Ramsay; Xing, Yun

    2007-12-01

    We present prevalence data for adolescents in a large metropolitan area in the US and the association of DSM-IV diagnoses to functional impairment and selected demographic correlates. We sampled 4175 youths aged 11-17 years from households enrolled in large health maintenance organizations. Data were collected using questionnaires and the Diagnostic Interview Schedule for Children, Version IV (DISC-IV). Impairment was measured using the Child Global Assessment Scale and diagnostic specific impairment in the DISC-IV. 17.1% of the sample met DSM-IV criteria for one or more disorders in the past year; 11% when only DISC impairment was considered and 5.3% only using the CGAS. The most prevalent disorders were anxiety (6.9%), disruptive (6.5%), and substance use (5.3%) disorders. The most prevalent specific disorders were agoraphobia, conduct and marijuana abuse/dependence, then alcohol use and oppositional defiant disorder. Younger youths and females had lower odds for any disorder, as did youths from two parent homes. There was increased odds associated with lower family income. Females had greater odds of mood and anxiety disorders, males of disruptive and substance use disorders. There were greater odds of mood and disruptive disorders for older youths. Prevalences were highly comparable to recent studies using similar methods in diverse non-metropolitan populations. We found associations with age, gender, and to a lesser extent, socioeconomic status reported in previous studies. The inclusion of both diagnosis-specific impairment and global impairment reduced prevalence rates significantly. Our results suggest commonality of prevalences and associated factors in diverse study settings, including urban and rural areas.

  15. Rates of DSM-IV Psychiatric Disorders Among Adolescents in a Large Metropolitan Area

    PubMed Central

    Roberts, Robert E.; Roberts, Catherine Ramsay; Xing, Yun

    2009-01-01

    We present prevalence data for adolescents in a large metropolitan area in the U.S. and the association of DSM-IV diagnoses to functional impairment and selected demographic correlates. We sampled 4,175 youths aged 11–17 years from households enrolled in large health maintenance organizations. Data were collected using questionnaires and the Diagnostic Interview Schedule for Children, Version IV (DISC-IV). Impairment was measured using the Child Global Assessment Scale and diagnostic specific impairment in the DISC-IV. 17.1% of the sample met DSM-IV criteria for one or more disorders in the past year; 11% when only DISC impairment was considered and 5.3% only using the CGAS. The most prevalent disorders were anxiety (6.9%), disruptive (6.5%), and substance use (5.3%) disorders. The most prevalent specific disorders were agoraphobia, conduct and marijuana abuse/dependence, then alcohol use and oppositional defiant disorder. Younger youths and females had lower odds for any disorder, as did youths from two parent homes. There was increased odds associated with lower family income. Females had greater odds of mood and anxiety disorders, males of disruptive and substance use disorders. There were greater odds of mood and disruptive disorders for older youths. Prevalences were highly comparable to recent studies using similar methods in diverse non-metropolitan populations. We found associations with age, gender, and to a lesser extent, socioeconomic status reported in previous studies. The inclusion of both diagnosis-specific impairment and global impairment reduced prevalence rates significantly. Our results suggest commonality of prevalences and associated factors in diverse study settings, including urban and rural areas. PMID:17107689

  16. Influence of shelf life on the setting time of type IV gypsum

    NASA Astrophysics Data System (ADS)

    Hapsari, M. L.; Irawan, B.; Damiyanti, M.

    2017-08-01

    Although expired materials can exhibit a deterioration in their properties, expired type IV gypsum can still be found on the market. In order to evaluate the influence of the shelf life on its setting time, two groups of type IV gypsum (GC Fuji rock EP) with different expiration dates were used in this research. The setting time tests were done in a mold using a Vicat Needle apparatus. The results of the statistical analysis showed a significant difference (p<0.05) between the two different expiration date groups. Therefore, the shelf life did influence the setting time of the type IV gypsum.

  17. Large-scale vertical motion calculations in the AVE IV Experiment. [of atmospheric wind velocity

    NASA Technical Reports Server (NTRS)

    Wilson, G. S.

    1976-01-01

    Using 3- and 6-h consecutive rawinsonde and surface data from NASA's AVE IV Experiment, synoptic-scale vertical motion calculations are made using an adiabatic technique and three variations of the kinematic technique. Both subjective and objective comparisons in space and time between the sign and magnitude of the computed vertical velocities and precipitation intensities are made. These comparisons are conducted to determine which method would consistently produce realistic magnitudes, patterns, and vertical profiles of vertical velocity essential to the diagnostic study of the relationship between severe convective storms and their environment in AVE IV. The kinematic method, adjusted to the adiabatic value at 100 mb, proved to produce the best overall vertical velocities.

  18. Peroxiredoxin IV regulates pro-inflammatory responses in large yellow croaker (Pseudosciaena crocea) and protects against bacterial challenge.

    PubMed

    Yu, Suhong; Mu, Yinnan; Ao, Jingqun; Chen, Xinhua

    2010-03-05

    In this study, we applied a comparative proteomic approach to the analysis of differentially expressed proteins in the spleens of large yellow croaker following treatment with an inactivated trivalent bacterial vaccine. Twenty-four altered proteins were identified by MALDI-TOF or MALDI-TOF-TOF, including immune-related proteins, antioxidant proteins, signal transducers, protein biosynthesis and catabolism modulators, and carbonic anhydrases. Three Prx family members, namely, Prx I, Prx II, and Prx IV, were upregulated after treatment with the vaccine, indicating potentially important roles for these antioxidant proteins in the antibacterial immune response. Large yellow croaker Prx IV (LycPrxIV), which has thiol-dependent peroxidase activity, was constitutively expressed in all tissues examined. Immunoelectron microscopy showed that LycPrxIV was primarily localized to the rER or peroxisome in spleen cells of healthy fish, and its synthesis on the rER increased following treatment with bacterial vaccine. Suppression of LycPrxIV by siRNA resulted in an increase in NF-kappaB activity in spleen tissues, while in vivo administration of recombinant LycPrxIV (rLycPrxIV) caused a decrease in NF-kappaB activity, indicating that LycPrxIV negatively regulates NF-kappaB activation. Likewise, siRNA-mediated knockdown of LycPrxIV increased the expression of TNF-alpha and CC chemokine, and downregulated the expression of IL-10. However, injection of fish with rLycPrxIV induced the opposite expression pattern of these cytokines, suggesting a role for LycPrxIV in regulating pro-inflammatory responses. Bacterial challenge experiments showed that suppression of LycPrxIV expression by siRNA significantly increased fish mortality as compared to controls, whereas rLycPrxIV provided a protective effect. Together, our data suggest that LycPrxIV may regulate pro-inflammatory responses to protect large yellow croaker from bacterial challenge, revealing a novel antibacterial mechanism in

  19. Timing signatures of large scale solar eruptions

    NASA Astrophysics Data System (ADS)

    Balasubramaniam, K. S.; Hock-Mysliwiec, Rachel; Henry, Timothy; Kirk, Michael S.

    2016-05-01

    We examine the timing signatures of large solar eruptions resulting in flares, CMEs and Solar Energetic Particle events. We probe solar active regions from the chromosphere through the corona, using data from space and ground-based observations, including ISOON, SDO, GONG, and GOES. Our studies include a number of flares and CMEs of mostly the M- and X-strengths as categorized by GOES. We find that the chromospheric signatures of these large eruptions occur 5-30 minutes in advance of coronal high temperature signatures. These timing measurements are then used as inputs to models and reconstruct the eruptive nature of these systems, and explore their utility in forecasts.

  20. Oblimersen Sodium and Combination Chemotherapy in Treating Patients With Newly Diagnosed Stage I, Stage II, Stage III, or Stage IV Diffuse Large B-Cell Lymphoma

    ClinicalTrials.gov

    2012-10-11

    Contiguous Stage II Adult Diffuse Large Cell Lymphoma; Noncontiguous Stage II Adult Diffuse Large Cell Lymphoma; Stage I Adult Diffuse Large Cell Lymphoma; Stage III Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma

  1. Optimization of gold nanoparticle-based real-time colorimetric assay of dipeptidyl peptidase IV activity.

    PubMed

    Aldewachi, Hasan Saad; Woodroofe, Nicola; Turega, Simon; Gardiner, Philip H E

    2017-07-01

    Dipeptidyl peptidase IV (DPP-IV also referred to as CD-26) is a serine protease enzyme with remarkable diagnostic and prognostic value in a variety of health and disease conditions. Herein, we describe a simple and real-time colorimetric assay for DPP-IV/CD-26 activity based on the aggregation of gold nanoparticles (AuNPs) functionalized with the peptide substrates: Gly-Pro-Asp-Cys (GPDC) or Val-Pro-ethylene diamine-Asp-Cys (VP-ED-DC). Cleavage of the substrates by DPP-IV resulted in aggregation of the AuNPs with accompanying color change in the solution from red to blue that was monitored using either a UV-visible spectrophotometer or by the naked eye. Factors, such as time course of the reaction, stability of the functionalized AuNPs and the structure of the substrate that influence the cleavage reaction in solution were investigated. The effects of potential interference from serum proteins (lysozyme, thrombin and trypsin) on the analytical response were negligible. The detection limits when GPDC or VP-EN-DC functionalized AuNPs were used for DPP-IV assay were 1.2U/L and 1.5U/L, respectively. The VP-EN-DC method was preferred for the quantitative determination of DPP-IV activity in serum because of its wide linear range 0-30U/L compared to 0-12U/L for the GPDC assay. Recoveries from serum samples spiked with DPP-IV activity, between 5 and 25U/L, and using the VP-EN-DC modified AuNPs method ranged between 83.6% and 114.9%. The two colorimetric biosensors described here are superior to other conventional methods because of their simplicity, stability, selectivity and reliability. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Timing Characteristics of Large Area Picosecond Photodetectors

    SciTech Connect

    Adams, Bernhard W.; Elagin, Andrey L.; Frisch, H.; Obaid, Razib; Oberla, E; Vostrikov, Alexander; Wagner, Robert G.; Wang, Jingbo; Wetstein, Matthew J.; Northrop, R

    2015-09-21

    The LAPPD Collaboration was formed to develop ultralast large-area imaging photodetectors based on new methods for fabricating microchannel plates (MCPs). In this paper we characterize the time response using a pulsed, sub picosecond laser. We observe single photoelectron time resolutions of a 20 cm x 20 cm MCP consistently below 70 ps, spatial resolutions of roughly 500 pm, and median gains higher than 10(7). The RMS measured at one particular point on an LAPPD detector is 58 ps, with in of 47 ps. The differential time resolution between the signal reaching the two ends of the delay line anode is measured to be 5.1 ps for large signals, with an asymptotic limit falling below 2 ps as noise-over-signal approaches zero.

  3. Optimization Integrator for Large Time Steps.

    PubMed

    Gast, Theodore F; Schroeder, Craig; Stomakhin, Alexey; Jiang, Chenfanfu; Teran, Joseph M

    2015-10-01

    Practical time steps in today's state-of-the-art simulators typically rely on Newton's method to solve large systems of nonlinear equations. In practice, this works well for small time steps but is unreliable at large time steps at or near the frame rate, particularly for difficult or stiff simulations. We show that recasting backward Euler as a minimization problem allows Newton's method to be stabilized by standard optimization techniques with some novel improvements of our own. The resulting solver is capable of solving even the toughest simulations at the [Formula: see text] frame rate and beyond. We show how simple collisions can be incorporated directly into the solver through constrained minimization without sacrificing efficiency. We also present novel penalty collision formulations for self collisions and collisions against scripted bodies designed for the unique demands of this solver. Finally, we show that these techniques improve the behavior of Material Point Method (MPM) simulations by recasting it as an optimization problem.

  4. Collagen IV-modified scaffolds improve islet survival and function and reduce time to euglycemia.

    PubMed

    Yap, Woon Teck; Salvay, David M; Silliman, Michael A; Zhang, Xiaomin; Bannon, Zachary G; Kaufman, Dixon B; Lowe, William L; Shea, Lonnie D

    2013-11-01

    Islet transplantation on extracellular matrix (ECM) protein-modified biodegradable microporous poly(lactide-co-glycolide) scaffolds is a potential curative treatment for type 1 diabetes mellitus (T1DM). Collagen IV-modified scaffolds, relative to control scaffolds, significantly decreased the time required to restore euglycemia from 17 to 3 days. We investigated the processes by which collagen IV-modified scaffolds enhanced islet function and mediated early restoration of euglycemia post-transplantation. We characterized the effect of collagen IV-modified scaffolds on islet survival, metabolism, and insulin secretion in vitro and early- and intermediate-term islet mass and vascular density post-transplantation and correlated these with early restoration of euglycemia in a syngeneic mouse model. Control scaffolds maintained native islet morphologies and architectures as well as collagen IV-modified scaffolds in vivo. The islet size and vascular density increased, while β-cell proliferation decreased from day 16 to 113 post-transplantation. Collagen IV-modified scaffolds promoted islet cell viability and decreased early-stage apoptosis in islet cells in vitro-phenomena that coincided with enhanced islet metabolic function and glucose-stimulated insulin secretion. These findings suggest that collagen IV-modified scaffolds promote the early restoration of euglycemia post-transplantation by enhancing islet metabolism and glucose-stimulated insulin secretion. These studies of ECM proteins, in particular collagen IV, and islet function provide key insights for the engineering of a microenvironment that would serve as a platform for enhancing islet transplantation as a viable clinical therapy for T1DM.

  5. Construct Validity of the WISC-IV[superscript UK] with a Large Referred Irish Sample

    ERIC Educational Resources Information Center

    Watkins, Marley W.; Canivez, Gary L.; James, Trevor; James, Kate; Good, Rebecca

    2013-01-01

    Irish educational psychologists frequently use the Wechsler Intelligence Scale for Children-Fourth U.K. Edition (WISC-IV[superscript UK]) in clinical assessments of children with learning difficulties. Unfortunately, reliability and validity studies of the WISC-IV[superscript UK] have not yet been reported. This study examined the construct…

  6. Construct Validity of the WISC-IV[superscript UK] with a Large Referred Irish Sample

    ERIC Educational Resources Information Center

    Watkins, Marley W.; Canivez, Gary L.; James, Trevor; James, Kate; Good, Rebecca

    2013-01-01

    Irish educational psychologists frequently use the Wechsler Intelligence Scale for Children-Fourth U.K. Edition (WISC-IV[superscript UK]) in clinical assessments of children with learning difficulties. Unfortunately, reliability and validity studies of the WISC-IV[superscript UK] have not yet been reported. This study examined the construct…

  7. Vorinostat, Rituximab, and Combination Chemotherapy in Treating Patients With Newly Diagnosed Stage II, Stage III, or Stage IV Diffuse Large B-Cell Lymphoma

    ClinicalTrials.gov

    2016-09-08

    Stage II Contiguous Adult Diffuse Large Cell Lymphoma; Stage II Non-Contiguous Adult Diffuse Large Cell Lymphoma; Stage III Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma

  8. Brentuximab Vedotin or Crizotinib and Combination Chemotherapy in Treating Patients With Newly Diagnosed Stage II-IV Anaplastic Large Cell Lymphoma

    ClinicalTrials.gov

    2017-10-02

    Anaplastic Large Cell Lymphoma, ALK-Positive; CD30-Positive Neoplastic Cells Present; Stage II Childhood Anaplastic Large Cell Lymphoma; Stage III Childhood Anaplastic Large Cell Lymphoma; Stage IV Childhood Anaplastic Large Cell Lymphoma

  9. Real Time Large Memory Optical Pattern Recognition.

    DTIC Science & Technology

    1984-06-01

    34 r G * The Multi-Foci Hololens .. ... .... .* .... .. * ...... * . ... . 37 111oI EXPERIMENTAL PROCEDURES...IV. EXPERIMENTAL RESULTS ...... s .. s ...... ..... .. 51 A. Testing of Hololens ..................... 51 - . B. The K Ratio...One Scene - Hololens Noise ....... 62 F. Twenty-Five Different Filters ................ 66 Go Seventy Different Filters

  10. Real-Time Series Resistance Monitoring in PV Systems Without the Need for IV Curves

    SciTech Connect

    Deceglie, Michael G.; Silverman, Timothy J.; Marion, Bill; Kurtz, Sarah R.

    2015-06-14

    We apply the physical principles of a familiar method, suns-Voc, to a new application: the real-time detection of series resistance changes in modules and systems operating outside. The real-time series resistance (RTSR) method that we describe avoids the need for collecting IV curves or constructing full series-resistance-free IV curves. RTSR is most readily deployable at the module level on micro-inverters or module-integrated electronics, but it can also be extended to full strings. Automated detection of series resistance increases can provide early warnings of some of the most common reliability issues, which also pose fire risks, including broken ribbons, broken solder bonds, and contact problems in the junction or combiner box. We describe the method in detail and describe a sample application to data collected from modules operating in the field.

  11. Influence of addition order and contact time on thorium(IV) retention by hematite in the presence of humic acids.

    PubMed

    Reiller, Pascal; Casanova, Florence; Moulin, Valérie

    2005-03-15

    The influence of addition order and contact time in the system hematite (alpha-Fe2O3)-humic acid (HA)-thorium(IV) (Th(IV)) was studied in batch experiments. Th(IV) is considered here as a chemical analogue of other actinides (IV). The sorption isotherms were acquired varying pH in the range 2-10 and HA concentration in the range 1-100 mg/L. As already observed by numerous authors, Th(IV) retention was hindered when HA and hematite were equilibrated beforehand during 24 h. As it has been observed in a previous study, this effect was drastic when the ratio between humic and surface (iron oxide) sites exceeds a critical value. However, when HA was added after a 24-h equilibration of the hematite-Th(IV) system, Th(IV) was barely desorbed from the iron oxide surface. Furthermore, no drastic effect of the ratio between humic and surface sites could be evidenced, as the increase of HA concentration only results in a slight monotonic decrease in Th(IV) retention. Increasing contact time between components of the systems only indicated slight Th(IV) retention variation. This was interpreted as a consequence of slow kinetic controls of both the Th(IV)-HA complexation and HA-hematite sorption.

  12. Administration time estimates for Wechsler Intelligence Scale for Children-IV subtests, composites, and short forms.

    PubMed

    Ryan, Joseph J; Glass, Laura A; Brown, Cassandra N

    2007-04-01

    The administration times for Wechsler Intelligence Scale for Children-IV (WISC-IV) subtests, indexes, and the Full Scale IQ were recorded for 57 school children. Also determined were administration times for eight short forms and the General Ability Index (GAI). All eight short forms reduced testing time by >50%, but the GAI required approximately 56 minutes. The time to administer the 10 core subtests that yield the Full Scale IQ and index scores averaged 72 minutes (range = 42 to 100), but 31% of the administrations required 80 minutes or longer. These results indicate that administration times are quite variable and that D. Wechsler's (2003) guideline of 65 to 80 minutes can be misleading for certain settings and for specific examinees. The present research found administration time to be positively correlated with examinee age, grade placement, and Full Scale IQ. In addition, the extent of examiner experience is known to be positively related to administration speed. In the present research, as in many settings, the examiners were competent, but not highly experienced.

  13. A novel mutation in a large family causes a unique phenotype of Mucolipidosis IV.

    PubMed

    AlBakheet, AlBandary; Qari, Aliya; Colak, Dilek; Rasheed, Anas; Kaya, Namik; Al-Sayed, Moeenaldeen

    2013-09-10

    Mucolipidosis type IV is a rare autosomal recessive lysosomal storage disorder reported among Ashkenazi Jews and to a lesser extent in other ethnic groups. Several mutations have been reported in MCOLN1 which is the only known gene associated with the disorder. Here we report the first Saudi patient with Mucolipidosis type IV from a consanguineous family with two branches having a total of five patients carrying a novel transition mutation, c.1307A>G (p.Y436C) in exon 11. The clinical course of the patient was nonspecific and a lysosomal storage disorder was not highly suspected due to lack of coarse facial features, organomegaly and skeletal findings of dysostosis multiplex. The detailed bioinformatics analysis on the deleterious effects of the mutation is discussed. Emphasis is made on the importance of brain magnetic resonance imaging (MRI) findings and serum gastrin level as key clues to the diagnosis of this often subtle neurodevelopmental disorder.

  14. Carfilzomib, Rituximab, Ifosfamide, Carboplatin, and Etoposide in Treating Patients With Relapsed or Refractory Stage I-IV Diffuse Large B-cell Lymphoma

    ClinicalTrials.gov

    2017-07-08

    CD20 Positive; Recurrent Diffuse Large B-Cell Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Stage I Diffuse Large B-Cell Lymphoma; Stage II Diffuse Large B-Cell Lymphoma; Stage III Diffuse Large B-Cell Lymphoma; Stage IV Diffuse Large B-Cell Lymphoma

  15. Association of the congenital neuromuscular form of glycogen storage disease type IV with a large deletion and recurrent frameshift mutation.

    PubMed

    Li, Sing-Chung; Hwu, Wuh-Liang; Lin, Ju-Li; Bali, Deeksha S; Yang, Chen; Chu, Shih-Ming; Chien, Yin-Hsiu; Chou, Hung-Chieh; Chen, Chien-Yi; Hsieh, Wu-Shiun; Tsao, Po-Nien; Chen, Yuan-Tsong; Lee, Ni-Chung

    2012-02-01

    Anderson disease, also known as glycogen storage disease type IV (MIM 232500), is a rare autosomal recessive disorder caused by a deficiency of glycogen branching enzyme. Glycogen storage disease type IV has a broad clinical spectrum ranging from a perinatal lethal form to a nonprogressive later-onset disease in adults. Here, we report 2 unrelated infants who were born small for their gestational age and who had profound hypotonia at birth and thus needed mechanical ventilation. Both of these patients shared the same frameshift mutation (c.288delA, pGly97GlufsX46) in the GBE1 gene. In addition, both of these patients were found to have 2 different large deletions in the GBE1 gene; exon 7 and exons 2 to 7, respectively, on the other alleles. This case report also highlights the need for a more comprehensive search for large deletion mutations associated with glycogen storage disease type IV, especially if routine GBE1 gene sequencing results are equivocal.

  16. Rapid detection of lineage IV peste des petits ruminants virus by real-time RT-PCR.

    PubMed

    Li, Lin; Wu, Xiaodong; Liu, Fuxiao; Wang, Zhiliang; Liu, Chunju; Wang, Qinghua; Bao, Jingyue

    2016-09-01

    Peste des petits ruminants virus (PPRV) is the cause agent of peste des petitis ruminants (PPR). A novel lineage IV PPRV has reemerged in China in 2013 and 2014. Mass vaccination was implemented in most provinces in China. In order to detect lineage IV PPRV in clinical samples and to distinguish rapidly it from the other lineages PPRVs, a real-time RT-PCR assay was developed. This assay showed high sensitivity, specificity and efficiency in differentiating the lineage IV PPRV from others. The performance of this assay was evaluated by positive clinical samples of lineage IV viruses. This new real-time RT-PCR assay will facilitate epidemiological investigations and rapid differentiatial diagnosis in areas where lineage IV viruses are circulating. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Large Magellanic Cloud Near-infrared Synoptic Survey. IV. Leavitt Laws for Type II Cepheid Variables

    NASA Astrophysics Data System (ADS)

    Bhardwaj, Anupam; Macri, Lucas M.; Rejkuba, Marina; Kanbur, Shashi M.; Ngeow, Chow-Choong; Singh, Harinder P.

    2017-04-01

    We present time-series observations of Population II Cepheids in the Large Magellanic Cloud at near-infrared (JHK s ) wavelengths. Our sample consists of 81 variables with accurate periods and optical (VI) magnitudes from the OGLE survey, covering various subtypes of pulsators (BL Herculis, W Virginis, and RV Tauri). We generate light-curve templates using high-quality I-band data in the LMC from OGLE and K s -band data in the Galactic bulge from VISTA Variables in Via Láctea survey and use them to obtain robust mean magnitudes. We derive period–luminosity (P–L) relations in the near-infrared and Period–Wesenheit (P–W) relations by combining optical and near-infrared data. Our P–L and P–W relations are consistent with published work when excluding long-period RV Tauris. We find that Pop II Cepheids and RR Lyraes follow the same P–L relations in the LMC. Therefore, we use trigonometric parallax from the Gaia DR1 for VY Pyx and the Hubble Space Telescope parallaxes for k Pav and 5 RR Lyrae variables to obtain an absolute calibration of the Galactic K s -band P–L relation, resulting in a distance modulus to the LMC of {μ }{LMC}=18.54+/- 0.08 mag. We update the mean magnitudes of Pop II Cepheids in Galactic globular clusters using our light-curve templates and obtain distance estimates to those systems, anchored to a precise late-type eclipsing binary distance to the LMC. We find that the distances to these globular clusters based on Pop II Cepheids are consistent (within 2σ ) with estimates based on the {M}V-[{Fe}/{{H}}] relation for horizontal branch stars.

  18. Simulating stochastic dynamics using large time steps.

    PubMed

    Corradini, O; Faccioli, P; Orland, H

    2009-12-01

    We present an approach to investigate the long-time stochastic dynamics of multidimensional classical systems, in contact with a heat bath. When the potential energy landscape is rugged, the kinetics displays a decoupling of short- and long-time scales and both molecular dynamics or Monte Carlo (MC) simulations are generally inefficient. Using a field theoretic approach, we perform analytically the average over the short-time stochastic fluctuations. This way, we obtain an effective theory, which generates the same long-time dynamics of the original theory, but has a lower time-resolution power. Such an approach is used to develop an improved version of the MC algorithm, which is particularly suitable to investigate the dynamics of rare conformational transitions. In the specific case of molecular systems at room temperature, we show that elementary integration time steps used to simulate the effective theory can be chosen a factor approximately 100 larger than those used in the original theory. Our results are illustrated and tested on a simple system, characterized by a rugged energy landscape.

  19. Interaction of a cumulus cloud ensemble with the large-scale environment. IV - The discrete model

    NASA Technical Reports Server (NTRS)

    Lord, S. J.; Chao, W. C.; Arakawa, A.

    1982-01-01

    The Arakawa-Schubert (1974) parameterization is applied to a prognostic model of large-scale atmospheric circulations and used to analyze data in a general circulation model (GCM). The vertical structure of the large-scale model and the solution for the cloud subensemble thermodynamical properties are examined to choose cloud levels and representative regions. A mass flux distribution equation is adapted to formulate algorithms for calculating the large-scale forcing and the mass flux kernel, using either direct solution or linear programming. Finally, the feedback of the cumulus ensemble on the large-scale environment for a given subensemble mass flux is calculated. All cloud subensemble properties were determined from the conservation of mass, moist static energy, and total water.

  20. Magnetic fields and large scale structure in a hot Universe. IV. The egg-carton Universe

    NASA Astrophysics Data System (ADS)

    Battaner, E.; Florido, E.

    1998-10-01

    Considering the possibility of a network of octahedra contacting at their vertexes for the large scale structure of the present Universe, as was discussed in previous papers of this series, we now try to identify real octahedra in the observed distribution of superclusters and voids. This identification is easy and clear. The network seems to have been deformed locally near the great mass associated to the large Piscis-Cetus complex.

  1. Topology of large-scale structure. IV - Topology in two dimensions

    NASA Technical Reports Server (NTRS)

    Melott, Adrian L.; Cohen, Alexander P.; Hamilton, Andrew J. S.; Gott, J. Richard, III; Weinberg, David H.

    1989-01-01

    In a recent series of papers, an algorithm was developed for quantitatively measuring the topology of the large-scale structure of the universe and this algorithm was applied to numerical models and to three-dimensional observational data sets. In this paper, it is shown that topological information can be derived from a two-dimensional cross section of a density field, and analytic expressions are given for a Gaussian random field. The application of a two-dimensional numerical algorithm for measuring topology to cross sections of three-dimensional models is demonstrated.

  2. Reionization on large scales. IV. Predictions for the 21 cm signal incorporating the light cone effect

    SciTech Connect

    La Plante, P.; Battaglia, N.; Natarajan, A.; Peterson, J. B.; Trac, H.; Cen, R.; Loeb, A.

    2014-07-01

    We present predictions for the 21 cm brightness temperature power spectrum during the Epoch of Reionization (EoR). We discuss the implications of the 'light cone' effect, which incorporates evolution of the neutral hydrogen fraction and 21 cm brightness temperature along the line of sight. Using a novel method calibrated against radiation-hydrodynamic simulations, we model the neutral hydrogen density field and 21 cm signal in large volumes (L = 2 Gpc h {sup –1}). The inclusion of the light cone effect leads to a relative decrease of about 50% in the 21 cm power spectrum on all scales. We also find that the effect is more prominent at the midpoint of reionization and later. The light cone effect can also introduce an anisotropy along the line of sight. By decomposing the 3D power spectrum into components perpendicular to and along the line of sight, we find that in our fiducial reionization model, there is no significant anisotropy. However, parallel modes can contribute up to 40% more power for shorter reionization scenarios. The scales on which the light cone effect is relevant are comparable to scales where one measures the baryon acoustic oscillation. We argue that due to its large comoving scale and introduction of anisotropy, the light cone effect is important when considering redshift space distortions and future application to the Alcock-Paczyński test for the determination of cosmological parameters.

  3. Fortran IV computer program for rapid hierarchical classification of large data sets

    NASA Astrophysics Data System (ADS)

    Jambu, Michel

    1981-01-01

    A rapid hierarchical classification program enables the clustering of 5000 elements in only a few minutes of central processor time using an IBM 370/168 computer. The program algorithm, based on the reductibility axiom in graph theory, is related to the criterion of correspondence analysis. Its application to a set of hydrogeological data is described briefly.

  4. The dynamics and control of large flexible space structures-IV

    NASA Technical Reports Server (NTRS)

    Bainum, P. M.; Kumar, V. K.; Krishna, R.; Reddy, A. S. S. R.

    1981-01-01

    The effects of solar radiation pressure as the main environmental disturbance torque were incorporated into the model of the rigid orbiting shallow shell and computer simulation results indicate that within the linear range the rigid modal amplitudes are excited in proportion to the area to mass ratio. The effect of higher order terms in the gravity-gradient torque expressions previously neglected was evaluated and found to be negligible for the size structures under consideration. A graph theory approach was employed for calculating the eigenvalues of a large flexible system by reducing the system (stiffness) matrix to lower ordered submatrices. The related reachability matrix and term rank concepts are used to verify controllability and can be more effective than the alternate numerical rank tests. Control laws were developed for the shape and orientation control of the orbiting flexible shallow shell and numerical results presented.

  5. THE GOULD'S BELT VERY LARGE ARRAY SURVEY. IV. THE TAURUS-AURIGA COMPLEX

    SciTech Connect

    Dzib, Sergio A.; Loinard, Laurent; Rodríguez, Luis F.; Ortiz-León, Gisela N.; Pech, Gerardo; Rivera, Juana L.; Mioduszewski, Amy J.; Kounkel, Marina A.; Hartmann, Lee; Torres, Rosa M.; Boden, Andrew F.; Evans II, Neal J.; Briceño, Cesar; Tobin, John

    2015-03-10

    We present a multi-epoch radio study of the Taurus-Auriga star-forming complex made with the Karl G. Jansky Very Large Array at frequencies of 4.5 GHz and 7.5 GHz. We detect a total of 610 sources, 59 of which are related to young stellar objects (YSOs) and 18 to field stars. The properties of 56% of the young stars are compatible with non-thermal radio emission. We also show that the radio emission of more evolved YSOs tends to be more non-thermal in origin and, in general, that their radio properties are compatible with those found in other star-forming regions. By comparing our results with previously reported X-ray observations, we notice that YSOs in Taurus-Auriga follow a Güdel-Benz relation with κ = 0.03, as we previously suggested for other regions of star formation. In general, YSOs in Taurus-Auriga and in all the previous studied regions seem to follow this relation with a dispersion of ∼1 dex. Finally, we propose that most of the remaining sources are related with extragalactic objects but provide a list of 46 unidentified radio sources whose radio properties are compatible with a YSO nature.

  6. The Time Domain Spectroscopic Survey: Spectroscopic Variability Investigations Within SDSS-IV/eBOSS

    NASA Astrophysics Data System (ADS)

    Green, Paul J.; Anderson, Scott F.; Morganson, Eric; Eracleous, Michael; Shen, Yue; Brandt, W. Niel; Ruan, John J.; Schmidt, Sarah J.; Badenes, Carles; West, Andrew A.; Ju, Wenhua; Greene, Jenny E.; Tdss, Panstarrs-1, Sdss-Iv

    2015-01-01

    The Time Domain Spectroscopic Survey (TDSS) is an SDSS-IV subproject that began summer 2014 and will continue for 4-6 years. Besides its main program to obtain initial characterization spectra of about 220,000 optical variables selected from PanSTARRS-1, the TDSS includes 9 separate smaller programs to study spectroscopic variability. We describe each of these Few-Epoch Spectroscopy (FES) programs, which target objects with existing SDSS spectroscopy amongst classes of quasars and stars of particular astrophysical interest. These include, in approximate order of decreasing sample size: Broad Absorption Line Quasars (BALQSOs), the most photometrically variable ("HyperVariable") quasars, high S/N normal broad line quasars, quasars with double-peaked or very asymmetric broad emission line profiles, Hypervariable stars, active ultracool (late-M and L-type) dwarf stars with Halpha emission, dwarf carbon stars, white dwarf/M dwarf spectroscopic binaries with Halpha emission, and binary supermassive black hole candidates from MgII broad line velocity shift analysis. We summarize herein the unique and diverse astrophysical investigations facilitated by these TDSS FES programs.

  7. RAGBEEF: a FORTRAN IV implementation of a time-dependent model for radionuclide contamination of beef

    SciTech Connect

    Pleasant, J C; McDowell-Boyer, L M; Killough, G G

    1982-06-01

    RAGBEEF is a FORTRAN IV program that calculates radionuclide concentrations in beef as a result of ingestion of contaminated feeds, pasture, and pasture soil by beef cattle. The model implemented by RAGBEEF is dynamic in nature, allowing the user to consider age- and season-dependent aspects of beef cattle management in estimating concentrations in beef. It serves as an auxiliary code to RAGTIME, previously documented by the authors, which calculates radionuclide concentrations in agricultural crops in a dynamic manner, but evaluates concentrations in beef for steady-state conditions only. The time-dependent concentrations in feeds, pasture, and pasture soil generated by RAGTIME are used as input to the RAGBEEF code. RAGBEEF, as presently implemented, calculates radionuclide concentrations in the muscle of age-based cohorts in a beef cattle herd. Concentrations in the milk of lactating cows are also calculated, but are assumed age-dependent as in RAGTIME. Radionuclide concentrations in beef and milk are described in RAGBEEF by a system of ordinary linear differential equations in which the transfer rate of radioactivity between compartments is proportional to the inventory of radioactivity in the source compartment. This system is solved by use of the GEAR package for solution of systems of ordinary differential equations. The accuracy of this solution is monitored at various check points by comparison with explicit solutions of Bateman-type equations. This report describes the age- and season-dependent considerations making up the RAGBEEF model, as well as presenting the equations which describe the model and a documentation of the associated computer code. Listings of the RAGBEEF and updated RAGTIME codes are provided in appendices, as are the results of a sample run of RAGBEEF and a description of recent modifications to RAGTIME.

  8. Serotype IV Streptococcus agalactiae ST-452 has arisen from large genomic recombination events between CC23 and the hypervirulent CC17 lineages.

    PubMed

    Campisi, Edmondo; Rinaudo, C Daniela; Donati, Claudio; Barucco, Mara; Torricelli, Giulia; Edwards, Morven S; Baker, Carol J; Margarit, Imma; Rosini, Roberto

    2016-07-14

    Streptococcus agalactiae (Group B Streptococcus, GBS) causes life-threatening infections in newborns and adults with chronic medical conditions. Serotype IV strains are emerging both among carriers and as cause of invasive disease and recent studies revealed two main Sequence Types (STs), ST-452 and ST-459 assigned to Clonal Complexes CC23 and CC1, respectively. Whole genome sequencing of 70 type IV GBS and subsequent phylogenetic analysis elucidated the localization of type IV isolates in a SNP-based phylogenetic tree and suggested that ST-452 could have originated through genetic recombination. SNPs density analysis of the core genome confirmed that the founder strain of this lineage originated from a single large horizontal gene transfer event between CC23 and the hypervirulent CC17. Indeed, ST-452 genomes are composed by two parts that are nearly identical to corresponding regions in ST-24 (CC23) and ST-291 (CC17). Chromosome mapping of the major GBS virulence factors showed that ST-452 strains have an intermediate yet unique profile among CC23 and CC17 strains. We described unreported large recombination events, involving the cps IV operon and resulting in the expansion of serotype IV to CC23. This work sheds further light on the evolution of GBS providing new insights on the recent emergence of serotype IV.

  9. Serotype IV Streptococcus agalactiae ST-452 has arisen from large genomic recombination events between CC23 and the hypervirulent CC17 lineages

    PubMed Central

    Campisi, Edmondo; Rinaudo, C. Daniela; Donati, Claudio; Barucco, Mara; Torricelli, Giulia; Edwards, Morven S.; Baker, Carol J.; Margarit, Imma; Rosini, Roberto

    2016-01-01

    Streptococcus agalactiae (Group B Streptococcus, GBS) causes life-threatening infections in newborns and adults with chronic medical conditions. Serotype IV strains are emerging both among carriers and as cause of invasive disease and recent studies revealed two main Sequence Types (STs), ST-452 and ST-459 assigned to Clonal Complexes CC23 and CC1, respectively. Whole genome sequencing of 70 type IV GBS and subsequent phylogenetic analysis elucidated the localization of type IV isolates in a SNP-based phylogenetic tree and suggested that ST-452 could have originated through genetic recombination. SNPs density analysis of the core genome confirmed that the founder strain of this lineage originated from a single large horizontal gene transfer event between CC23 and the hypervirulent CC17. Indeed, ST-452 genomes are composed by two parts that are nearly identical to corresponding regions in ST-24 (CC23) and ST-291 (CC17). Chromosome mapping of the major GBS virulence factors showed that ST-452 strains have an intermediate yet unique profile among CC23 and CC17 strains. We described unreported large recombination events, involving the cps IV operon and resulting in the expansion of serotype IV to CC23. This work sheds further light on the evolution of GBS providing new insights on the recent emergence of serotype IV. PMID:27411639

  10. Two-Dimensional Large Gap Topological Insulators with Tunable Rashba Spin-Orbit Coupling in Group-IV films.

    PubMed

    Zhang, Shou-Juan; Ji, Wei-Xiao; Zhang, Chang-Wen; Li, Ping; Wang, Pei-Ji

    2017-04-03

    The coexistence of nontrivial topology and giant Rashba splitting, however, has rare been observed in two-dimensional (2D) films, limiting severely its potential applications at room temperature. Here, we through first-principles calculations to propose a series of inversion-asymmetric group-IV films, ABZ2 (A ≠ B = Si, Ge, Sn, Pb; Z = F, Cl, Br), whose stability are confirmed by phonon spectrum calculations. The analyses of electronic structures reveal that they are intrinsic 2D TIs with a bulk gap as large as 0.74 eV, except for GeSiF2, SnSiCl2, GeSiCl2 and GeSiBr2 monolayers which can transform from normal to topological phases under appropriate tensile strain of 4, 4, 5, and 4%, respectively. The nontrivial topology is identified by Z2 topological invariant together with helical edge states, as well as the berry curvature of these systems. Another prominent intriguing feature is the giant Rashba spin splitting with a magnitude reaching 0.15 eV, the largest value reported in 2D films so far. The tunability of Rashba SOC and band topology can be realized through achievable compressive/tensile strains (-4 ~ 6%). Also, the BaTe semiconductor is an ideal substrate for growing ABZ2 films without destroying their nontrivial topology.

  11. Two-Dimensional Large Gap Topological Insulators with Tunable Rashba Spin-Orbit Coupling in Group-IV films

    PubMed Central

    Zhang, Shou-juan; Ji, Wei-xiao; Zhang, Chang-wen; Li, Ping; Wang, Pei-ji

    2017-01-01

    The coexistence of nontrivial topology and giant Rashba splitting, however, has rare been observed in two-dimensional (2D) films, limiting severely its potential applications at room temperature. Here, we through first-principles calculations to propose a series of inversion-asymmetric group-IV films, ABZ2 (A ≠ B = Si, Ge, Sn, Pb; Z = F, Cl, Br), whose stability are confirmed by phonon spectrum calculations. The analyses of electronic structures reveal that they are intrinsic 2D TIs with a bulk gap as large as 0.74 eV, except for GeSiF2, SnSiCl2, GeSiCl2 and GeSiBr2 monolayers which can transform from normal to topological phases under appropriate tensile strain of 4, 4, 5, and 4%, respectively. The nontrivial topology is identified by Z2 topological invariant together with helical edge states, as well as the berry curvature of these systems. Another prominent intriguing feature is the giant Rashba spin splitting with a magnitude reaching 0.15 eV, the largest value reported in 2D films so far. The tunability of Rashba SOC and band topology can be realized through achievable compressive/tensile strains (−4 ~ 6%). Also, the BaTe semiconductor is an ideal substrate for growing ABZ2 films without destroying their nontrivial topology. PMID:28368035

  12. Real-time detection of transients in OGLE-IV with application of machine learning

    NASA Astrophysics Data System (ADS)

    Klencki, Jakub; Wyrzykowski, Łukasz

    2016-06-01

    The current bottleneck of transient detection in most surveys is the problem of rejecting numerous artifacts from detected candidates. We present a triple-stage hierarchical machine learning system for automated artifact filtering in difference imaging, based on self-organizing maps. The classifier, when tested on the OGLE-IV Transient Detection System, accepts 97% of real transients while removing up to 97.5% of artifacts.

  13. NPSNET-IV: A Real-Time, 3D Distributed Interactive Virtual World

    DTIC Science & Technology

    1993-09-01

    NPSNET-IV, an autonomous vehicle control system was developed to help populate the simulation. One of the autonomous agents was a Loch Ness monster ...new entity type was needed. As a sea vessel, the Loch Ness monster 35 was restricted to the surface of the lake. As a base vehicle type, the remote...instead of just coming to the surface. The Loch Ness monster needed the same kind of movement restrictions that a submarine or fish would need. It needs

  14. Real-Time Series Resistance Monitoring in PV Systems Without the Need for I-V Curves

    SciTech Connect

    Deceglie, Michael G.; Silverman, Timothy J.; Marion, Bill; Kurtz, Sarah R.

    2015-10-01

    We apply the physical principles of a familiar method, suns-Voc, to a new application: the real-time detection of series resistance changes in modules and systems operating outside. The real-time series resistance (RTSR) method that we describe avoids the need for collecting I-V curves or constructing full series resistance-free I-V curves. RTSR is most readily deployable at the module level on microinverters or module-integrated electronics, but it can also be extended to full strings. We found that automated detection of series resistance increases can provide early warnings of some of the most common reliability issues, which also pose fire risks, including broken ribbons, broken solder bonds, and contact problems in the junction or combiner box. We also describe the method in detail and describe a sample application to data collected from modules operating in the field.

  15. Real-time Data Streams from ``e-RemoteCtrl'' to Central VLBI Network Status Monitoring Services Like IVS Live

    NASA Astrophysics Data System (ADS)

    Neidhardt, Alexander; Collioud, Arnaud

    2014-12-01

    A central VLBI network status monitoring can be realized by using online status information about current VLBI sessions, real-time, and status data directly from each radio telescope. Such monitoring helps to organize sessions or to get immediate feedback from the active telescopes. Therefore the remote control software for VLBI radio telescopes ``e-RemoteCtrl'' (http://www.econtrol-software.de), which enables remote access as extension to the NASA Field System, realizes real-time data streams to dedicated data centers. The software has direct access to the status information about the current observation (e.g., schedule, scan, source) and the telescope (e.g., current state, temperature, pressure) in real-time. This information are directly sent to ``IVS Live''. ``IVS Live'' (http://ivslive.obs.u-bordeaux1.fr/) is a Web tool that can be used to follow the observing sessions, organized by the International VLBI Service for Geodesy and Astrometry (IVS), navigate through past or upcoming sessions, or search and display specific information about sessions, sources (like VLBI images), and stations, by using an Internet browser.

  16. Predictors of Local Recurrence After Rituximab-Based Chemotherapy Alone in Stage III and IV Diffuse Large B-Cell Lymphoma: Guiding Decisions for Consolidative Radiation

    SciTech Connect

    Jegadeesh, Naresh; Rajpara, Raj; Esiashvili, Natia; Shi, Zheng; Liu, Yuan; Okwan-Duodu, Derrick; Flowers, Christopher R.; Khan, Mohammad K.

    2015-05-01

    Purpose: The role of consolidative radiation therapy (RT) for stage III and IV diffuse large B-cell lymphoma (DLBCL) in the era of rituximab is not well defined. There is evidence that some patients with bulky disease may benefit, but patient selection criteria are not well established. We sought to identify a subset of patients who experienced a high local failure rate after receiving rituximab-based chemotherapy alone and hence may benefit from the addition of consolidative RT. Methods and Materials: Two hundred eleven patients with stage III and IV DLBCL treated between August 1999 and January 2012 were reviewed. Of these, 89 had a complete response to systemic therapy including rituximab and received no initial RT. Kaplan-Meier analysis and Cox proportional hazards regression were performed, with local recurrence (LR) as the primary outcome. Results: The median follow-up time was 43.9 months. Fifty percent of patients experienced LR at 5 years. In multivariate analysis, tumor ≥5 cm and stage III disease were associated with increased risk of LR. The 5-year LR-free survival was 47.4% for patients with ≥5-cm lesions versus 74.7% for patients with <5-cm lesions (P=.01). In patients with <5-cm tumors, the maximum standardized uptake value (SUVmax) was ≥15 in all patients with LR. The 5-year LR-free survival was 100% in SUV<15 versus 68.8% in SUV≥15 (P=.10). Conclusions: Advanced-stage DLBCL patients with stage III disease or with disease ≥5 cm appear to be at an increased risk for LR. Patients with <5-cm disease and SUVmax ≥15 may be at higher risk for LR. These patients may benefit from consolidative RT after chemoimmunotherapy.

  17. Predictors of local recurrence after rituximab-based chemotherapy alone in stage III and IV diffuse large B-cell lymphoma: guiding decisions for consolidative radiation.

    PubMed

    Jegadeesh, Naresh; Rajpara, Raj; Esiashvili, Natia; Shi, Zheng; Liu, Yuan; Okwan-Duodu, Derrick; Flowers, Christopher R; Khan, Mohammad K

    2015-05-01

    The role of consolidative radiation therapy (RT) for stage III and IV diffuse large B-cell lymphoma (DLBCL) in the era of rituximab is not well defined. There is evidence that some patients with bulky disease may benefit, but patient selection criteria are not well established. We sought to identify a subset of patients who experienced a high local failure rate after receiving rituximab-based chemotherapy alone and hence may benefit from the addition of consolidative RT. Two hundred eleven patients with stage III and IV DLBCL treated between August 1999 and January 2012 were reviewed. Of these, 89 had a complete response to systemic therapy including rituximab and received no initial RT. Kaplan-Meier analysis and Cox proportional hazards regression were performed, with local recurrence (LR) as the primary outcome. The median follow-up time was 43.9 months. Fifty percent of patients experienced LR at 5 years. In multivariate analysis, tumor ≥ 5 cm and stage III disease were associated with increased risk of LR. The 5-year LR-free survival was 47.4% for patients with ≥ 5-cm lesions versus 74.7% for patients with <5-cm lesions (P=.01). In patients with <5-cm tumors, the maximum standardized uptake value (SUVmax) was ≥ 15 in all patients with LR. The 5-year LR-free survival was 100% in SUV<15 versus 68.8% in SUV ≥ 15 (P=.10). Advanced-stage DLBCL patients with stage III disease or with disease ≥ 5 cm appear to be at an increased risk for LR. Patients with <5-cm disease and SUVmax ≥ 15 may be at higher risk for LR. These patients may benefit from consolidative RT after chemoimmunotherapy. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Ovarian Cancer Stage IV

    MedlinePlus

    ... hyphen, e.g. -historical Searches are case-insensitive Ovarian Cancer Stage IV Add to My Pictures View /Download : ... 1200x1335 View Download Large: 2400x2670 View Download Title: Ovarian Cancer Stage IV Description: Drawing of stage IV shows ...

  19. Power-law time distribution of large earthquakes.

    PubMed

    Mega, Mirko S; Allegrini, Paolo; Grigolini, Paolo; Latora, Vito; Palatella, Luigi; Rapisarda, Andrea; Vinciguerra, Sergio

    2003-05-09

    We study the statistical properties of time distribution of seismicity in California by means of a new method of analysis, the diffusion entropy. We find that the distribution of time intervals between a large earthquake (the main shock of a given seismic sequence) and the next one does not obey Poisson statistics, as assumed by the current models. We prove that this distribution is an inverse power law with an exponent mu=2.06+/-0.01. We propose the long-range model, reproducing the main properties of the diffusion entropy and describing the seismic triggering mechanisms induced by large earthquakes.

  20. CFD Time-Integration Strategies for Large Chemical Systems

    DTIC Science & Technology

    2006-03-29

    Final Report: CFD Time-Integration Strategies for Large Chemical Systems F49620-03-1-0208 William M. Eppard Ph.D. AeroSoft , Inc. 1872 Pratt Drive...UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER Aerosoft , Inc. 1872 Pratt Drive, Suite 1275...Eppard at AeroSoft , Inc. 5 Publications Damkohler Limiting of Chemical Time Scales - Paper Number : AIAA-2005-1400 6 Interactions/Transitions Dr

  1. Large-scale environment of z ˜ 5.7 C IV absorption systems - I. Projected distribution of galaxies

    NASA Astrophysics Data System (ADS)

    Díaz, C. Gonzalo; Koyama, Yusei; Ryan-Weber, Emma V.; Cooke, Jeff; Ouchi, Masami; Shimasaku, Kazuhiro; Nakata, Fumiaki

    2014-08-01

    Metal absorption systems are products of star formation. They are believed to be associated with massive star-forming galaxies, which have significantly enriched their surroundings. To test this idea with high column density C IV absorption systems at z ˜ 5.7, we study the projected distribution of galaxies and characterize the environment of C IV systems in two independent quasar lines of sight: J103027.01+052455.0 and J113717.73+354956.9. Using wide-field photometry (˜80 × 60 h-1 comoving Mpc), we select bright (MUV(1350 Å) ≲ -21.0 mag.) Lyman break galaxies (LBGs) at z ˜ 5.7 in a redshift slice Δz ˜ 0.2 and we compare their projected distribution with z ˜ 5.7 narrow-band selected Lyman alpha emitters (LAEs, Δz ˜ 0.08). We find that the C IV systems are located more than 10 h-1 projected comoving Mpc from the main concentrations of LBGs and no candidate is closer than ˜5 h-1 projected comoving Mpc. In contrast, an excess of LAEs - lower mass galaxies - is found on scales of ˜10 h-1 comoving Mpc, suggesting that LAEs are the primary candidates for the source of the C IV systems. Furthermore, the closest object to the system in the field J1030+0524 is a faint LAE at a projected distance of 212 h-1 physical kpc. However, this work cannot rule out undiscovered lower mass galaxies as the origin of these absorption systems. We conclude that, in contrast with lower redshift examples (z ≲ 3.5), strong C IV absorption systems at z ˜ 5.7 trace low-to-intermediate density environments dominated by low-mass galaxies. Moreover, the excess of LAEs associated with high levels of ionizing flux agrees with the idea that faint galaxies dominate the ionizing photon budget at this redshift.

  2. I-V and noise performance in MWIR to VLWIR large area Hg1-xCdxTe photodiodes

    NASA Astrophysics Data System (ADS)

    D'Souza, A. I.; Stapelbroek, M. G.; Dolan, P. N.; Wijewarnasuriya, P. S.; Boehmer, E.; Smith, D. S.; Ehlert, J. C.; Andrews, J. E.

    2005-05-01

    , diffusion current limited photodiodes having values of αdark in the mid 10-6 range. All of the 850 μm diameter, λc ~ 15.5 μm photodiodes measured have excess low frequency noise, with the best performers having in(f = 100 Hz, Vd =-60 mV , Δf = 1 Hz) ~ 2 x 10-11 A/Hz1/2 and the best photodiode αdark = 3.92 x 10-6. I-V measurements, noise, and visual inspections are performed at several steps in the photodiodes manufacturing process. It was observed, following FPM fabrication, photodiode dark current and noise had increased from the initial pre-mounting leadless chip carrier (LCC) measurements for some of the nine photodiodes. The performance degradation observed led to an investigation into the cause (baking at elevated temperatures, mechanical handling, electrical stress etc.) of photodiode degradation that occurred between LCC and FPM testing. Correlations between I-V, noise and surface visual defects have been performed on some λc ~ 15.5 mm photodiodes. This paper outlines the results of the study, correlating the electrical performance observed to visual defects on the surface and to defects seen following cross sectioning of degraded photodiodes. In addition, other lessons learned and the corrective actions implemented that led to the successful manufacture of SWIR, MWIR and LWIR large photodiodes from the material growth to insertion into and successful demonstration of flight FPMs for the CrIS program are described.

  3. Visualizing frequent patterns in large multivariate time series

    NASA Astrophysics Data System (ADS)

    Hao, M.; Marwah, M.; Janetzko, H.; Sharma, R.; Keim, D. A.; Dayal, U.; Patnaik, D.; Ramakrishnan, N.

    2011-01-01

    The detection of previously unknown, frequently occurring patterns in time series, often called motifs, has been recognized as an important task. However, it is difficult to discover and visualize these motifs as their numbers increase, especially in large multivariate time series. To find frequent motifs, we use several temporal data mining and event encoding techniques to cluster and convert a multivariate time series to a sequence of events. Then we quantify the efficiency of the discovered motifs by linking them with a performance metric. To visualize frequent patterns in a large time series with potentially hundreds of nested motifs on a single display, we introduce three novel visual analytics methods: (1) motif layout, using colored rectangles for visualizing the occurrences and hierarchical relationships of motifs in a multivariate time series, (2) motif distortion, for enlarging or shrinking motifs as appropriate for easy analysis and (3) motif merging, to combine a number of identical adjacent motif instances without cluttering the display. Analysts can interactively optimize the degree of distortion and merging to get the best possible view. A specific motif (e.g., the most efficient or least efficient motif) can be quickly detected from a large time series for further investigation. We have applied these methods to two real-world data sets: data center cooling and oil well production. The results provide important new insights into the recurring patterns.

  4. Time simulation of flutter with large stiffness changes

    NASA Technical Reports Server (NTRS)

    Karpel, Mordechay; Wieseman, Carol D.

    1992-01-01

    Time simulation of flutter, involving large local structural changes, is formulated with a state-space model that is based on a relatively small number of generalized coordinates. Free-free vibration modes are first calculated for a nominal finite-element model with relatively large fictitious masses located at the area of structural changes. A low-frequency subset of these modes is then transformed into a set of structural modal coordinates with which the entire simulation is performed. These generalized coordinates and the associated oscillatory aerodynamic force coefficient matrices are used to construct an efficient time-domain, state-space model for a basic aeroelastic case. The time simulation can then be performed by simply changing the mass, stiffness, and damping coupling terms when structural changes occur. It is shown that the size of the aeroelastic model required for time simulation with large structural changes at a few apriori known locations is similar to that required for direct analysis of a single structural case. The method is applied to the simulation of an aeroelastic wind-tunnel model. The diverging oscillations are followed by the activation of a tip-ballast decoupling mechanism that stabilizes the system but may cause significant transient overshoots.

  5. Time simulation of flutter with large stiffness changes

    NASA Technical Reports Server (NTRS)

    Karpel, M.; Wieseman, C. D.

    1992-01-01

    Time simulation of flutter, involving large local structural changes, is formulated with a state-space model that is based on a relatively small number of generalized coordinates. Free-free vibration modes are first calculated for a nominal finite-element model with relatively large fictitious masses located at the area of structural changes. A low-frequency subset of these modes is then transformed into a set of structural modal coordinates with which the entire simulation is performed. These generalized coordinates and the associated oscillatory aerodynamic force coefficient matrices are used to construct an efficient time-domain, state-space model for basic aeroelastic case. The time simulation can then be performed by simply changing the mass, stiffness and damping coupling terms when structural changes occur. It is shown that the size of the aeroelastic model required for time simulation with large structural changes at a few a priori known locations is similar to that required for direct analysis of a single structural case. The method is applied to the simulation of an aeroelastic wind-tunnel model. The diverging oscillations are followed by the activation of a tip-ballast decoupling mechanism that stabilizes the system but may cause significant transient overshoots.

  6. The High Time Resolution Universe Pulsar Survey - IV. Discovery and polarimetry of millisecond pulsars: HTRU IV: discovery and polarization of MSPs

    SciTech Connect

    Keith, M. J.; Johnston, S.; Bailes, M.; Bates, S. D.; Bhat, N. D. R.; Burgay, M.; Burke-Spolaor, S.; D’Amico, N.; Jameson, A.; Kramer, M.; Levin, L.; Milia, S.; Possenti, A.; Stappers, B. W.; van Straten, W.; Parent, D.

    2011-11-03

    We present the discovery of six millisecond pulsars (MSPs) in the High Time Reso- lution Universe (HTRU) survey for pulsars and fast transients carried out with the Parkes radio telescope. All six are in binary systems with approximately circular or- bits and are likely to have white dwarf companions. PSR J1017–7156 has a high flux density and a narrow pulse width, making it ideal for precision timing experiments. PSRs J1446–4701 and J1125–5825 are coincident with gamma-ray sources, and fold- ing the high-energy photons with the radio timing ephemeris shows evidence of pulsed gamma-ray emission. PSR J1502–6752 has a spin period of 26.7 ms, and its low period derivative implies that it is a recycled pulsar. The orbital parameters indicate it has a very low mass function, and therefore a companion mass much lower than usually expected for such a mildly recycled pulsar. In addition we present polarisation profiles for all 12 MSPs discovered in the HTRU survey to date. Similar to previous observations of MSPs, we find that many have large widths and a wide range of linear and circular polarisation fractions. Their polarisation profiles can be highly complex, and although the observed position angles often do not obey the rotating vector model, we present several examples of those that do. We speculate that the emission heights of MSPs are a substantial fraction of the light cylinder radius in order to explain broad emission profiles, which then naturally leads to a large number of cases where emission from both poles is observed.

  7. The High Time Resolution Universe Pulsar Survey - IV. Discovery and polarimetry of millisecond pulsars: HTRU IV: discovery and polarization of MSPs

    DOE PAGES

    Keith, M. J.; Johnston, S.; Bailes, M.; ...

    2011-11-03

    We present the discovery of six millisecond pulsars (MSPs) in the High Time Reso- lution Universe (HTRU) survey for pulsars and fast transients carried out with the Parkes radio telescope. All six are in binary systems with approximately circular or- bits and are likely to have white dwarf companions. PSR J1017–7156 has a high flux density and a narrow pulse width, making it ideal for precision timing experiments. PSRs J1446–4701 and J1125–5825 are coincident with gamma-ray sources, and fold- ing the high-energy photons with the radio timing ephemeris shows evidence of pulsed gamma-ray emission. PSR J1502–6752 has a spin periodmore » of 26.7 ms, and its low period derivative implies that it is a recycled pulsar. The orbital parameters indicate it has a very low mass function, and therefore a companion mass much lower than usually expected for such a mildly recycled pulsar. In addition we present polarisation profiles for all 12 MSPs discovered in the HTRU survey to date. Similar to previous observations of MSPs, we find that many have large widths and a wide range of linear and circular polarisation fractions. Their polarisation profiles can be highly complex, and although the observed position angles often do not obey the rotating vector model, we present several examples of those that do. We speculate that the emission heights of MSPs are a substantial fraction of the light cylinder radius in order to explain broad emission profiles, which then naturally leads to a large number of cases where emission from both poles is observed.« less

  8. Exploring large scale time-series data using nested timelines

    NASA Astrophysics Data System (ADS)

    Xie, Zaixian; Ward, Matthew O.; Rundensteiner, Elke A.

    2013-01-01

    When data analysts study time-series data, an important task is to discover how data patterns change over time. If the dataset is very large, this task becomes challenging. Researchers have developed many visualization techniques to help address this problem. However, little work has been done regarding the changes of multivariate patterns, such as linear trends and clusters, on time-series data. In this paper, we describe a set of history views to fill this gap. This technique works under two modes: merge and non-merge. For the merge mode, merge algorithms were applied to selected time windows to generate a change-based hierarchy. Contiguous time windows having similar patterns are merged first. Users can choose different levels of merging with the tradeoff between more details in the data and less visual clutter in the visualizations. In the non-merge mode, the framework can use natural hierarchical time units or one defined by domain experts to represent timelines. This can help users navigate across long time periods. Gridbased views were designed to provide a compact overview for the history data. In addition, MDS pattern starfields and distance maps were developed to enable users to quickly investigate the degree of pattern similarity among different time periods. The usability evaluation demonstrated that most participants could understand the concepts of the history views correctly and finished assigned tasks with a high accuracy and relatively fast response time.

  9. Large-time limit of the quantum Zeno effect

    NASA Astrophysics Data System (ADS)

    Facchi, Paolo; Ligabò, Marilena

    2017-03-01

    If very frequent periodic measurements ascertain whether a quantum system is still in its initial state, its evolution is hindered. This peculiar phenomenon is called quantum Zeno effect. We investigate the large-time limit of the survival probability as the total observation time scales as a power of the measurement frequency, t ∝Nα . The limit survival probability exhibits a sudden jump from 1 to 0 at α =1 /2 , the threshold between the quantum Zeno effect and a diffusive behavior. Moreover, we show that for α ≥1 , the limit probability becomes sensitive to the spectral properties of the initial state and to the arithmetic properties of the measurement periods.

  10. Just in time connectivity for large spiking networks

    PubMed Central

    Lytton, William W.; Omurtag, Ahmet; Neymotin, Samuel A; Hines, Michael L

    2008-01-01

    The scale of large neuronal network simulations is memory-limited due to the need to store connectivity information: connectivity storage grows as the square of neuron number up to anatomically-relevant limits. Using the NEURON simulator as a discrete-event simulator (no integration), we explored the consequences of avoiding the space costs of connectivity through regenerating connectivity parameters when needed – just-in-time after a presynaptic cell fires. We explored various strategies for automated generation of one or more of the basic static connectivity parameters: delays, postsynaptic cell identities and weights, as well as run-time connectivity state: the event queue. Comparison of the JitCon implementation to NEURON’s standard NetCon connectivity method showed substantial space savings, with associated run-time penalty. Although JitCon saved space by eliminating connectivity parameters, larger simulations were still memory-limited due to growth of the synaptic event queue. We therefore designed a JitEvent algorithm that only added items to the queue when required: instead of alerting multiple postsynaptic cells, a spiking presynaptic cell posted a callback event at the shortest synaptic delay time. At the time of the callback, this same presynaptic cell directly notified the first postsynaptic cell and generated another self-callback for the next delay time. The JitEvent implementation yielded substantial additional time and space savings. We conclude that just-in-time strategies are necessary for very large network simulations but that a variety of alternative strategies should be considered whose optimality will depend on the characteristics of the simulation to be run. PMID:18533821

  11. Just-in-time connectivity for large spiking networks.

    PubMed

    Lytton, William W; Omurtag, Ahmet; Neymotin, Samuel A; Hines, Michael L

    2008-11-01

    The scale of large neuronal network simulations is memory limited due to the need to store connectivity information: connectivity storage grows as the square of neuron number up to anatomically relevant limits. Using the NEURON simulator as a discrete-event simulator (no integration), we explored the consequences of avoiding the space costs of connectivity through regenerating connectivity parameters when needed: just in time after a presynaptic cell fires. We explored various strategies for automated generation of one or more of the basic static connectivity parameters: delays, postsynaptic cell identities, and weights, as well as run-time connectivity state: the event queue. Comparison of the JitCon implementation to NEURON's standard NetCon connectivity method showed substantial space savings, with associated run-time penalty. Although JitCon saved space by eliminating connectivity parameters, larger simulations were still memory limited due to growth of the synaptic event queue. We therefore designed a JitEvent algorithm that added items to the queue only when required: instead of alerting multiple postsynaptic cells, a spiking presynaptic cell posted a callback event at the shortest synaptic delay time. At the time of the callback, this same presynaptic cell directly notified the first postsynaptic cell and generated another self-callback for the next delay time. The JitEvent implementation yielded substantial additional time and space savings. We conclude that just-in-time strategies are necessary for very large network simulations but that a variety of alternative strategies should be considered whose optimality will depend on the characteristics of the simulation to be run.

  12. FTSPlot: Fast Time Series Visualization for Large Datasets

    PubMed Central

    Riss, Michael

    2014-01-01

    The analysis of electrophysiological recordings often involves visual inspection of time series data to locate specific experiment epochs, mask artifacts, and verify the results of signal processing steps, such as filtering or spike detection. Long-term experiments with continuous data acquisition generate large amounts of data. Rapid browsing through these massive datasets poses a challenge to conventional data plotting software because the plotting time increases proportionately to the increase in the volume of data. This paper presents FTSPlot, which is a visualization concept for large-scale time series datasets using techniques from the field of high performance computer graphics, such as hierarchic level of detail and out-of-core data handling. In a preprocessing step, time series data, event, and interval annotations are converted into an optimized data format, which then permits fast, interactive visualization. The preprocessing step has a computational complexity of ; the visualization itself can be done with a complexity of and is therefore independent of the amount of data. A demonstration prototype has been implemented and benchmarks show that the technology is capable of displaying large amounts of time series data, event, and interval annotations lag-free with ms. The current 64-bit implementation theoretically supports datasets with up to bytes, on the x86_64 architecture currently up to bytes are supported, and benchmarks have been conducted with bytes/1 TiB or double precision samples. The presented software is freely available and can be included as a Qt GUI component in future software projects, providing a standard visualization method for long-term electrophysiological experiments. PMID:24732865

  13. Factors Associated with Screen Time in Iranian Children and Adolescents: The CASPIAN-IV Study.

    PubMed

    Mozafarian, Nafiseh; Motlagh, Mohammad Esmaeil; Heshmat, Ramin; Karimi, Siavash; Mansourian, Morteza; Mohebpour, Fatemeh; Qorbani, Mostafa; Kelishadi, Roya

    2017-01-01

    Prolonged screen time is frequent in children and adolescents. Implementing interventions to reduce physical inactivity needs to assess related determinants. This study aims to assess factors associated with screen time in a national sample of children and adolescents. This nationwide study was conducted among 14,880 students aged 6-18 years. Data collection was performed using questionnaires and physical examination. The World Health Organization-Global School Health Survey questionnaire was used. Logistic regression analysis was used to examine the relationship between demographic variables, socioeconomic status (SES), family structure, physical activity, unhealthy eating habits, body mass index, and mental distress with screen time. The participation rate was 90.6% (n = 13,486), 50.8% were male, and 75.6% lived in urban areas. Mean (standard deviation) age of participants was 12.47 (3.36) years. The SES, eating junk foods, urban residence, and age had significant association with screen time, watching television (TV), and computer use (P < 0.05). With increasing number of children, the odds ratio of watching TV reduced (P < 0.001). Statistically, significant association existed between obesity and increased time spent watching TV (P < 0.001). Girls spent less likely to use computer and to have prolonged screen time (P < 0.001). Participants in the sense of worthlessness were less likely to watch TV (P = 0.005). Screen time, watching TV, and using computer were higher in students with aggressive behaviors (P < 0.001); screen time was higher in those with insomnia. In this study, higher SES, unhealthy food habits, and living in urban areas, as well as aggressive behaviors and insomnia increased the risk of physical inactivity.

  14. Stage IV advanced diffuse large B-cell lymphoma in human immunodeficiency virus infection with achieving cure by using highly active antiretroviral therapy alone: a case report.

    PubMed

    Lim, Do Hyoung; Rhee, Ji-Young; Park, Keon Woo

    2017-08-01

    After the introduction of highly active antiretroviral therapy (HAART), there has been a decrease in the incidence of lymphoma among the HIV-infected population and also significantly improved survival rates. We describe a remarkable case of an HIV-infected patient with advanced stage IV diffuse large B-cell lymphoma (DLBCL), completely regressed with the use of HAART alone. He remained disease-free for 6 years and he achieved cure without chemotherapy. Although several cases of low-grade lymphoma with complete regression were reported, we could not find any case of stage IV high-grade malignant lymphoma with HAART alone in complete remission for over 5 years from our review of the literature. This unique case shows the importance of HAART in improving survival and achieving cure in HIV-high-grade malignant lymphoma.

  15. Time-Domain Filtering for Spatial Large-Eddy Simulation

    NASA Technical Reports Server (NTRS)

    Pruett, C. David

    1997-01-01

    An approach to large-eddy simulation (LES) is developed whose subgrid-scale model incorporates filtering in the time domain, in contrast to conventional approaches, which exploit spatial filtering. The method is demonstrated in the simulation of a heated, compressible, axisymmetric jet, and results are compared with those obtained from fully resolved direct numerical simulation. The present approach was, in fact, motivated by the jet-flow problem and the desire to manipulate the flow by localized (point) sources for the purposes of noise suppression. Time-domain filtering appears to be more consistent with the modeling of point sources; moreover, time-domain filtering may resolve some fundamental inconsistencies associated with conventional space-filtered LES approaches.

  16. Large holographic displays for real-time applications

    NASA Astrophysics Data System (ADS)

    Schwerdtner, A.; Häussler, R.; Leister, N.

    2008-02-01

    Holography is generally accepted as the ultimate approach to display three-dimensional scenes or objects. Principally, the reconstruction of an object from a perfect hologram would appear indistinguishable from viewing the corresponding real-world object. Up to now two main obstacles have prevented large-screen Computer-Generated Holograms (CGH) from achieving a satisfactory laboratory prototype not to mention a marketable one. The reason is a small cell pitch CGH resulting in a huge number of hologram cells and a very high computational load for encoding the CGH. These seemingly inevitable technological hurdles for a long time have not been cleared limiting the use of holography to special applications, such as optical filtering, interference, beam forming, digital holography for capturing the 3-D shape of objects, and others. SeeReal Technologies has developed a new approach for real-time capable CGH using the socalled Tracked Viewing Windows technology to overcome these problems. The paper will show that today's state of the art reconfigurable Spatial Light Modulators (SLM), especially today's feasible LCD panels are suited for reconstructing large 3-D scenes which can be observed from large viewing angles. For this to achieve the original holographic concept of containing information from the entire scene in each part of the CGH has been abandoned. This substantially reduces the hologram resolution and thus the computational load by several orders of magnitude making thus real-time computation possible. A monochrome real-time prototype measuring 20 inches has been built and demonstrated at last year's SID conference and exhibition 2007 and at several other events.

  17. Galactic cannibalism. IV. The evidence-correlations between dynamical time scales and Bautz-Morgan type

    SciTech Connect

    McGlynn, T.A.; Ostriker, J.P.

    1980-11-01

    If the luminosity of supergiant cD galaxies in particular, and the Bautz-Morgan sequence of galaxy types in general, is produced by dynamical evolutionary processes, then one expects to find a correlation between dynamical times and ..delta..M/sub 12/, the magnitude difference between first and second brightest cluster members.

  18. Transit Timing Observations from Kepler: IV. Confirmation of 4 Multiple Planet Systems by Simple Physical Models

    SciTech Connect

    Fabrycky, Daniel C.; Ford, Eric B.; Steffen, Jason H.; Rowe, Jason F.; Carter, Joshua A.; Moorhead, Althea V.; Batalha, Natalie M.; Borucki, William J.; Bryson, Steve; Buchhave, Lars A.; Christiansen, Jessie L.; /SETI Inst., Mtn. View /NASA, Ames /Caltech

    2012-01-01

    Eighty planetary systems of two or more planets are known to orbit stars other than the Sun. For most, the data can be sufficiently explained by non-interacting Keplerian orbits, so the dynamical interactions of these systems have not been observed. Here we present 4 sets of lightcurves from the Kepler spacecraft, which each show multiple planets transiting the same star. Departure of the timing of these transits from strict periodicity indicates the planets are perturbing each other: the observed timing variations match the forcing frequency of the other planet. This confirms that these objects are in the same system. Next we limit their masses to the planetary regime by requiring the system remain stable for astronomical timescales. Finally, we report dynamical fits to the transit times, yielding possible values for the planets masses and eccentricities. As the timespan of timing data increases, dynamical fits may allow detailed constraints on the systems architectures, even in cases for which high-precision Doppler follow-up is impractical.

  19. How To Dance through Time. Volume IV: The Elegance of Baroque Social Dance. [Videotape].

    ERIC Educational Resources Information Center

    Teten, Carol

    This 45-minute VHS videotape is the fourth in a series of "How To Dance Through Time" videos. It shows how to dance the most influential social dances of the French Baroque Court. The ceremonious Minuet is the most famous of the 18th century dance invention. The Allemande is the pivotal bridge linking to the 19th century. The Contredance…

  20. Association between screen time and snack consumption in children and adolescents: The CASPIAN-IV study.

    PubMed

    Kelishadi, Roya; Mozafarian, Nafiseh; Qorbani, Mostafa; Maracy, Mohammad Reza; Motlagh, Mohammad Esmaeil; Safiri, Saeid; Ardalan, Gelayol; Asayesh, Hamid; Rezaei, Fatemeh; Heshmat, Ramin

    2017-02-01

    The relationship between screen time (ST) and the frequency of snack consumption in a national sample of Iranian children and adolescents was assessed. The present nationwide survey was conducted on 14,880 school students living in urban and rural areas of 30 provinces in Iran. Trained healthcare providers conducted the physical examination and completed the questionnaire of the World Health Organization - Global School-Based Student Health Survey (WHO-GSHS). The association between ST (total time spent watching TV and using a computer in leisure time) and the frequency of snack consumption was determined using ordinal logistic regression analysis. The subjects were 13,486 students out of the 14,880 invited including 50.8% boys. The mean (SD) age of participants was 12.47 (3.36) years. In multivariate models, for students who had prolonged ST (more than 4 h/day), the odds of daily consumption of sweets (odds ratio, OR 1.25; 95% CI 1.14-1.4), salty snacks (OR 1.6; 95% CI 1.5-1.76), soft drinks (OR 1.52; 95% CI 1.4-1.7), canned fruit juice (OR 1.3; 95% CI 1.2-1.4), and fast food (OR 1.53; 95% CI 1.4-1.7) were higher compared to those with low ST. Furthermore, the odds of daily consumption of milk in students who had prolonged ST (more than 4 h/day) were lower compared to those with low ST (OR 0.9; 95% CI 0.8-0.99). Prolonged time spent watching TV and using a computer during leisure time might be associated with unhealthy dietary habits. Moreover, inactivity induced by prolonged ST may also lead to unhealthy dietary habits and in turn excess weight in children and adolescents.

  1. Real-time distributed map building in large environments

    NASA Astrophysics Data System (ADS)

    Julier, Simon J.; Uhlmann, Jeffrey K.

    2000-10-01

    Many of the future missions for mobile robots demand multi- robot systems which are capable of operating in large environments for long periods of time. One of the most critical capabilities is the ability to localize- a mobile robot must be able to estimate its own position and to consistently transmit this information to other robots and control sites. Although state-of-the-art GPS is capable of yielding unmatched performance over large areas, it is not applicable in many environments (such as within city streets, under water, indoors, beneath foliage or extra- terrestrial robotic missions) where mobile robots are likely to become commonplace. A widely researched alternative is Simultaneous Localization and Map Building (SLAM): the vehicle constructs a map and, concurrently, estimates its own position. However, most approaches are non-scalable (the storage and computational costs vary quadratically and cubically with the number of beacons in the map) and can only be used with multiple robotic vehicles with a great degree of difficulty. In this paper, we describe the development of a scalable, multiple-vehicle SLAM system. This system, based on the Covariance Intersection algorithm, is scalable- its storage and computational costs are linearly proportional to the number of beacons in the map. Furthermore, it is scalable to multiple robots- each has complete freedom to exchange partial or full map information with any other robot at any other time step. We demonstrate the real-time performance of this system in a scenario of 15,000 beacons.

  2. Studies in astronomical time series analysis. IV - Modeling chaotic and random processes with linear filters

    NASA Technical Reports Server (NTRS)

    Scargle, Jeffrey D.

    1990-01-01

    While chaos arises only in nonlinear systems, standard linear time series models are nevertheless useful for analyzing data from chaotic processes. This paper introduces such a model, the chaotic moving average. This time-domain model is based on the theorem that any chaotic process can be represented as the convolution of a linear filter with an uncorrelated process called the chaotic innovation. A technique, minimum phase-volume deconvolution, is introduced to estimate the filter and innovation. The algorithm measures the quality of a model using the volume covered by the phase-portrait of the innovation process. Experiments on synthetic data demonstrate that the algorithm accurately recovers the parameters of simple chaotic processes. Though tailored for chaos, the algorithm can detect both chaos and randomness, distinguish them from each other, and separate them if both are present. It can also recover nonminimum-delay pulse shapes in non-Gaussian processes, both random and chaotic.

  3. Studies in astronomical time series analysis. IV - Modeling chaotic and random processes with linear filters

    NASA Technical Reports Server (NTRS)

    Scargle, Jeffrey D.

    1990-01-01

    While chaos arises only in nonlinear systems, standard linear time series models are nevertheless useful for analyzing data from chaotic processes. This paper introduces such a model, the chaotic moving average. This time-domain model is based on the theorem that any chaotic process can be represented as the convolution of a linear filter with an uncorrelated process called the chaotic innovation. A technique, minimum phase-volume deconvolution, is introduced to estimate the filter and innovation. The algorithm measures the quality of a model using the volume covered by the phase-portrait of the innovation process. Experiments on synthetic data demonstrate that the algorithm accurately recovers the parameters of simple chaotic processes. Though tailored for chaos, the algorithm can detect both chaos and randomness, distinguish them from each other, and separate them if both are present. It can also recover nonminimum-delay pulse shapes in non-Gaussian processes, both random and chaotic.

  4. Large area spark counter with fine time and position resolution

    SciTech Connect

    Ogawa, A.; Fujiwara, N.; Pestov, Yu.N.; Sugahara, R.

    1984-03-01

    The key properties of spark counters include their capability of precision timing (at the sub 100 ps level) and of measuring the position of the charged particle to high accuracy. At SLAC we have undertaken a program to develop these devices for use in high energy physics experiments involving large detectors. A spark counter of size 1.2 m x 0.1 m has been constructed and has been operating continuously in our test setup for several months. Some details of its construction and its properties as a particle detector are reported. 14 references. (WHK)

  5. Time-predictable recurrence model for large earthquakes

    SciTech Connect

    Shimazaki, K.; Nakata, T.

    1980-04-01

    We present historical and geomorphological evidence of a regularity in earthquake recurrence at three different sites of plate convergence around the Japan arcs. The regularity shows that the larger an earthquake is, the longer is the following quiet period. In other words, the time interval between two successive large earthquakes is approximately proportional to the amount of coseismic displacement of the preceding earthquake and not of the following earthquake. The regularity enables us, in principle, to predict the approximate occurrence time of earthquakes. The data set includes 1) a historical document describing repeated measurements of water depth at Murotsu near the focal region of Nankaido earthquakes, 2) precise levelling and /sup 14/C dating of Holocene uplifted terraces in the southern boso peninsula facing the Sagami trough, and 3) similar geomorphological data on exposed Holocene coral reefs in Kikai Island along the Ryukyu arc.

  6. Roux-en-Y gastric bypass for obesity after Belsey-Mark IV for large hiatus hernia and intrathoracic stomach, in combination with gastroesophageal reflux disease.

    PubMed

    Haenen, Filip; Gys, Ben; Gys, Tobie; Lafullarde, Thierry

    2016-07-05

    Obesity is an increasing problem worldwide; patients who remain obese after non-surgical interventions are potential candidates for surgical intervention. Laparoscopic Roux-en-Y gastric bypass (RYGB) has proven its effects on excess weight loss and its positive effect on comorbidities and also, on reflux correction. Our patient, a 53-year-old male, with a BMI of 45 kg/m(2) and type 2 diabetes, underwent a Belsey-Mark IV procedure in another center because of a large hiatus hernia and intrathoracic stomach, in combination with gastroesophageal reflux disease (GERD). He consulted at our center concerning his morbid obesity. After a positive preoperative evaluation a RYGB was performed with an uneventful postoperative course. RYGB is a safe and feasible procedure to perform after a Belsey-Mark IV procedure. To our knowledge, this is the first and only report of a RYGB after a Belsey-Mark IV procedure. There were no intra-operative complications and 18 months follow-up was unremarkable, with a 78.10% excess weight loss (EWL), at 86 kg, and no remaining symptoms of GERD. We also mention resolution of the patient's diabetes mellitus type 2 measured by the cessation of the glucophage, which is an added health benefit.

  7. The Large Observatory for x-ray timing

    NASA Astrophysics Data System (ADS)

    Feroci, M.; den Herder, J. W.; Bozzo, E.; Barret, D.; Brandt, S.; Hernanz, M.; van der Klis, M.; Pohl, M.; Santangelo, A.; Stella, L.; Watts, A.; Wilms, J.; Zane, S.; Ahangarianabhari, M.; Albertus, C.; Alford, M.; Alpar, A.; Altamirano, D.; Alvarez, L.; Amati, L.; Amoros, C.; Andersson, N.; Antonelli, A.; Argan, A.; Artigue, R.; Artigues, B.; Atteia, J.-L.; Azzarello, P.; Bakala, P.; Baldazzi, G.; Balman, S.; Barbera, M.; van Baren, C.; Bhattacharyya, S.; Baykal, A.; Belloni, T.; Bernardini, F.; Bertuccio, G.; Bianchi, S.; Bianchini, A.; Binko, P.; Blay, P.; Bocchino, F.; Bodin, P.; Bombaci, I.; Bonnet Bidaud, J.-M.; Boutloukos, S.; Bradley, L.; Braga, J.; Brown, E.; Bucciantini, N.; Burderi, L.; Burgay, M.; Bursa, M.; Budtz-Jørgensen, C.; Cackett, E.; Cadoux, F. R.; Caïs, P.; Caliandro, G. A.; Campana, R.; Campana, S.; Capitanio, F.; Casares, J.; Casella, P.; Castro-Tirado, A. J.; Cavazzuti, E.; Cerda-Duran, P.; Chakrabarty, D.; Château, F.; Chenevez, J.; Coker, J.; Cole, R.; Collura, A.; Cornelisse, R.; Courvoisier, T.; Cros, A.; Cumming, A.; Cusumano, G.; D'Ai, A.; D'Elia, V.; Del Monte, E.; de Luca, A.; de Martino, D.; Dercksen, J. P. C.; de Pasquale, M.; De Rosa, A.; Del Santo, M.; Di Cosimo, S.; Diebold, S.; Di Salvo, T.; Donnarumma, I.; Drago, A.; Durant, M.; Emmanoulopoulos, D.; Erkut, M. H.; Esposito, P.; Evangelista, Y.; Fabian, A.; Falanga, M.; Favre, Y.; Feldman, C.; Ferrari, V.; Ferrigno, C.; Finger, M.; Finger, M. H.; Fraser, G. W.; Frericks, M.; Fuschino, F.; Gabler, M.; Galloway, D. K.; Galvez Sanchez, J. L.; Garcia-Berro, E.; Gendre, B.; Gezari, S.; Giles, A. B.; Gilfanov, M.; Giommi, P.; Giovannini, G.; Giroletti, M.; Gogus, E.; Goldwurm, A.; Goluchová, K.; Götz, D.; Gouiffes, C.; Grassi, M.; Groot, P.; Gschwender, M.; Gualtieri, L.; Guidorzi, C.; Guy, L.; Haas, D.; Haensel, P.; Hailey, M.; Hansen, F.; Hartmann, D. H.; Haswell, C. A.; Hebeler, K.; Heger, A.; Hermsen, W.; Homan, J.; Hornstrup, A.; Hudec, R.; Huovelin, J.; Ingram, A.; In't Zand, J. J. M.; Israel, G.; Iwasawa, K.; Izzo, L.; Jacobs, H. M.; Jetter, F.; Johannsen, T.; Jonker, P.; Josè, J.; Kaaret, P.; Kanbach, G.; Karas, V.; Karelin, D.; Kataria, D.; Keek, L.; Kennedy, T.; Klochkov, D.; Kluzniak, W.; Kokkotas, K.; Korpela, S.; Kouveliotou, C.; Kreykenbohm, I.; Kuiper, L. M.; Kuvvetli, I.; Labanti, C.; Lai, D.; Lamb, F. K.; Laubert, P. P.; Lebrun, F.; Lin, D.; Linder, D.; Lodato, G.; Longo, F.; Lund, N.; Maccarone, T. J.; Macera, D.; Maestre, S.; Mahmoodifar, S.; Maier, D.; Malcovati, P.; Mandel, I.; Mangano, V.; Manousakis, A.; Marisaldi, M.; Markowitz, A.; Martindale, A.; Matt, G.; McHardy, I. M.; Melatos, A.; Mendez, M.; Mereghetti, S.; Michalska, M.; Migliari, S.; Mignani, R.; Miller, M. C.; Miller, J. M.; Mineo, T.; Miniutti, G.; Morsink, S.; Motch, C.; Motta, S.; Mouchet, M.; Mouret, G.; Mulačová, J.; Muleri, F.; Muñoz-Darias, T.; Negueruela, I.; Neilsen, J.; Norton, A. J.; Nowak, M.; O'Brien, P.; Olsen, P. E. H.; Orienti, M.; Orio, M.; Orlandini, M.; Orleański, P.; Osborne, J. P.; Osten, R.; Ozel, F.; Pacciani, L.; Paolillo, M.; Papitto, A.; Paredes, J. M.; Patruno, A.; Paul, B.; Perinati, E.; Pellizzoni, A.; Penacchioni, A. V.; Perez, M. A.; Petracek, V.; Pittori, C.; Pons, J.; Portell, J.; Possenti, A.; Poutanen, J.; Prakash, M.; Le Provost, P.; Psaltis, D.; Rambaud, D.; Ramon, P.; Ramsay, G.; Rapisarda, M.; Rachevski, A.; Rashevskaya, I.; Ray, P. S.; Rea, N.; Reddy, S.; Reig, P.; Reina Aranda, M.; Remillard, R.; Reynolds, C.; Rezzolla, L.; Ribo, M.; de la Rie, R.; Riggio, A.; Rios, A.; Rodríguez-Gil, P.; Rodriguez, J.; Rohlfs, R.; Romano, P.; Rossi, E. M. R.; Rozanska, A.; Rousseau, A.; Ryde, F.; Sabau-Graziati, L.; Sala, G.; Salvaterra, R.; Sanna, A.; Sandberg, J.; Scaringi, S.; Schanne, S.; Schee, J.; Schmid, C.; Shore, S.; Schneider, R.; Schwenk, A.; Schwope, A. D.; Seyler, J.-Y.; Shearer, A.; Smith, A.; Smith, D. M.; Smith, P. J.; Sochora, V.; Soffitta, P.; Soleri, P.; Spencer, A.; Stappers, B.; Steiner, A. W.; Stergioulas, N.; Stratta, G.; Strohmayer, T. E.; Stuchlik, Z.; Suchy, S.; Sulemainov, V.; Takahashi, T.; Tamburini, F.; Tauris, T.; Tenzer, C.; Tolos, L.; Tombesi, F.; Tomsick, J.; Torok, G.; Torrejon, J. M.; Torres, D. F.; Tramacere, A.; Trois, A.; Turolla, R.; Turriziani, S.; Uter, P.; Uttley, P.; Vacchi, A.; Varniere, P.; Vaughan, S.; Vercellone, S.; Vrba, V.; Walton, D.; Watanabe, S.; Wawrzaszek, R.; Webb, N.; Weinberg, N.; Wende, H.; Wheatley, P.; Wijers, R.; Wijnands, R.; Wille, M.; Wilson-Hodge, C. A.; Winter, B.; Wood, K.; Zampa, G.; Zampa, N.; Zampieri, L.; Zdunik, L.; Zdziarski, A.; Zhang, B.; Zwart, F.; Ayre, M.; Boenke, T.; Corral van Damme, C.; Kuulkers, Erik; Lumb, D.

    2014-07-01

    The Large Observatory For x-ray Timing (LOFT) was studied within ESA M3 Cosmic Vision framework and participated in the final downselection for a launch slot in 2022-2024. Thanks to the unprecedented combination of effective area and spectral resolution of its main instrument, LOFT will study the behaviour of matter under extreme conditions, such as the strong gravitational field in the innermost regions of accretion flows close to black holes and neutron stars, and the supranuclear densities in the interior of neutron stars. The science payload is based on a Large Area Detector (LAD, 10 m2 effective area, 2-30 keV, 240 eV spectral resolution, 1° collimated field of view) and a Wide Field Monitor (WFM, 2-50 keV, 4 steradian field of view, 1 arcmin source location accuracy, 300 eV spectral resolution). The WFM is equipped with an on-board system for bright events (e.g. GRB) localization. The trigger time and position of these events are broadcast to the ground within 30 s from discovery. In this paper we present the status of the mission at the end of its Phase A study.

  8. Irregular Morphing for Real-Time Rendering of Large Terrain

    NASA Astrophysics Data System (ADS)

    Kalem, Sid'Ali; Kourgli, Assia

    2016-06-01

    The following paper proposes an alternative approach to the real-time adaptive triangulation problem. A new region-based multi-resolution approach for terrain rendering is described which improves on-the-fly the distribution of the density of triangles inside the tile after selecting appropriate Level-Of-Detail by an adaptive sampling. This proposed approach organizes the heightmap into a QuadTree of tiles that are processed independently. This technique combines the benefits of both Triangular Irregular Network approach and region-based multi-resolution approach by improving the distribution of the density of triangles inside the tile. Our technique morphs the initial regular grid of the tile to deformed grid in order to minimize approximation error. The proposed technique strives to combine large tile size and real-time processing while guaranteeing an upper bound on the screen space error. Thus, this approach adapts terrain rendering process to local surface characteristics and enables on-the-fly handling of large amount of terrain data. Morphing is based-on the multi-resolution wavelet analysis. The use of the D2WT multi-resolution analysis of the terrain height-map speeds up processing and permits to satisfy an interactive terrain rendering. Tests and experiments demonstrate that Haar B-Spline wavelet, well known for its properties of localization and its compact support, is suitable for fast and accurate redistribution. Such technique could be exploited in client-server architecture for supporting interactive high-quality remote visualization of very large terrain.

  9. Prevalence of DSM-IV and DSM-5 Alcohol, Cocaine, Opioid, and Cannabis Use Disorders in a Largely Substance Dependent Sample

    PubMed Central

    Peer, Kyle; Rennert, Lior; Lynch, Kevin G.; Farrer, Lindsay; Gelernter, Joel; Kranzler, Henry R.

    2012-01-01

    BACKGROUND The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) will soon replace the DSM-IV, which has existed for nearly two decades. The changes in diagnostic criteria have important implications for research and for the clinical care of individuals with Substance Use Disorders (SUDs). METHODS We used the Semi-Structured Assessment for Drug Dependence and Alcoholism to evaluate the lifetime presence of DSM-IV abuse and dependence diagnoses and DSM-5 mild, moderate, or severe SUDs for alcohol, cocaine, opioids, and cannabis in a sample of 7,543 individuals recruited to participate in genetic studies of substance dependence. RESULTS Switches between diagnostic systems consistently resulted in a modestly greater prevalence for DSM-5 SUDs, based largely on the assignment of DSM-5 diagnoses to DSM-IV “diagnostic ophans” (i.e., individuals meeting one or two criteria for dependence and none for abuse, and thus not receiving a DSM-IV SUD diagnosis). The vast majority of these diagnostic switches were attributable to the requirement that only two of 11 criteria be met for a DSM-5 SUD diagnosis. We found evidence to support the omission from DSM-5 of the legal criterion due to its limited diagnostic utility. The addition of craving as a criterion in DSM-5 did not substantially affect the likelihood of an SUD diagnosis. CONCLUSION The greatest advantage of DSM-5 appears to be its ability to capture diagnostic orphans. In this sample, changes reflected in DSM-5 had a minimal impact on the prevalence of SUD diagnoses. PMID:22884164

  10. Theoretical study of time-resolved luminescence in semiconductors. IV. Lateral inhomogeneities

    NASA Astrophysics Data System (ADS)

    Maiberg, Matthias; Bertram, Frank; Müller, Mathias; Scheer, Roland

    2017-02-01

    In the fourth part of this series, we study the impact of lateral inhomogeneities on the time-resolved luminescence decay (TRL) after a pulsed excitation by means of simulation with Synopsys® TCAD and analytical approximation. This work consists of two parts: In the first part, the effect of excitations being inhomogeneous on a lateral scale is investigated. It turns out that for localized excitations there may be a strong lateral diffusion of charge carriers, thereby limiting the resolution of a micro-TRL experiment. In this case, a replacement of the inhomogeneous excitation in the simulation by a homogeneous excitation and an average photon density is not possible, especially due to defect saturation depending non-linearly on the excitation. In the second part, we consider a homogeneous excitation and study inhomogeneous material parameters, namely, inhomogeneous charge carrier lifetimes, band gaps, and doping densities. We find that their effects strongly depend on their characteristic lengths of variation. For length scales smaller than the diffusion length, inhomogeneous material parameters can lead to curved luminescence decays.

  11. Large area spark counters with fine time and position resolution

    SciTech Connect

    Ogawa, A.; Atwood, W.B.; Fujiwara, N.; Pestov, Yu.N.; Sugahara, R.

    1983-10-01

    Spark counters trace their history back over three decades but have been used in only a limited number of experiments. The key properties of these devices include their capability of precision timing (at the sub 100 ps level) and of measuring the position of the charged particle to high accuracy. At SLAC we have undertaken a program to develop these devices for use in high energy physics experiments involving large detectors. A spark counter of size 1.2 m x 0.1 m has been constructed and has been operating continuously in our test setup for several months. In this talk I will discuss some details of its construction and its properties as a particle detector. 14 references.

  12. Real-time radiography of Titan IV Solid Rocket Motor Upgrade (SRMU) static firing test QM-2

    SciTech Connect

    Dolan, K.W.; Curnow, G.M.; Perkins, D.E.; Schneberk, D.J.; Costerus, B.W.; La Chapell, M.J.; Turner, D.E.; Wallace, P.W.

    1994-03-08

    Real-time radiography was successfully applied to the Titan-IV Solid Rocket Motor Upgrade (SRMU) static firing test QM-2 conducted February 22, 1993 at Phillips Laboratory, Edwards AFB, CA. The real-time video data obtained in this test gave the first incontrovertible evidence that the molten slag pool is low (less than 5 to 6 inches in depth referenced to the bottom of the aft dome cavity) before T + 55 seconds, builds fairly linearly from this point in time reaching a quasi-equilibrium depth of 16 to 17 inches at about T + 97 seconds, which is well below the top of the vectored nozzle, and maintains that level until T + 125 near the end motor burn. From T + 125 seconds to motor burn-out at T + 140 seconds the slag pool builds to a maximum depth of about 20 to 21 inches, still well below the top of the nozzle. The molten slag pool was observed to interact with motions of the vectored nozzle, and exhibit slosh and wave mode oscillations. A few slag ejection events were also observed.

  13. Large Scale Time Series Microscopy of Neovessel Growth During Angiogenesis

    PubMed Central

    Utzinger, Urs; Baggett, Brenda; Weiss, Jeffrey A.; Hoying, James B.; Edgar, Lowell T.

    2016-01-01

    During angiogenesis, growing neovessels must effectively navigate through the tissue space as they elongate and subsequently integrate into a microvascular network. While time series microscopy has provided insight into the cell activities within single growing neovessel sprouts, less in known concerning neovascular dynamics within a large angiogenic tissue bed. Here we developed a time lapse imaging technique that allowed visualization and quantification of sprouting neovessels as they form and grow away from adult parent microvessels in 3-dimensions over cubic millimeters of matrix volume, over the course of up to 5 days on the microscope. Using a new image acquisition procedure and novel morphometric analysis tools, we quantified the elongation dynamics of growing neovessels and found an episodic growth pattern accompanied by fluctuations in neovessel diameter. Average elongation rate was 5 microns/hour for individual vessels, but we also observed considerable dynamic variability in growth character including retraction and complete regression of entire neovessels. We observed neovessel-to-neovessel directed growth over tens to hundreds of microns preceding tip-to-tip inosculation. As we have previously described via static 3D imaging at discrete time points, we identified different collagen fibril structures associated with the growing neovessel tip and stalk, and observed the coordinated alignment of growing neovessels in a deforming matrix. Overall analysis of the entire image volumes demonstrated that although individual neovessels exhibited episodic growth and regression, there was a monotonic increase in parameters associated with the entire vascular bed such as total network length and number of branch points. This new time-lapse imaging approach corroborated morphometric changes in individual neovessels described by us and others, as well as captured dynamic neovessel behaviors unique to days-long angiogenesis within the forming neovascular network. PMID

  14. Parallel Rendering of Large Time-Varying Volume Data

    NASA Technical Reports Server (NTRS)

    Garbutt, Alexander E.

    2005-01-01

    Interactive visualization of large time-varying 3D volume datasets has been and still is a great challenge to the modem computational world. It stretches the limits of the memory capacity, the disk space, the network bandwidth and the CPU speed of a conventional computer. In this SURF project, we propose to develop a parallel volume rendering program on SGI's Prism, a cluster computer equipped with state-of-the-art graphic hardware. The proposed program combines both parallel computing and hardware rendering in order to achieve an interactive rendering rate. We use 3D texture mapping and a hardware shader to implement 3D volume rendering on each workstation. We use SGI's VisServer to enable remote rendering using Prism's graphic hardware. And last, we will integrate this new program with ParVox, a parallel distributed visualization system developed at JPL. At the end of the project, we Will demonstrate remote interactive visualization using this new hardware volume renderer on JPL's Prism System using a time-varying dataset from selected JPL applications.

  15. Parallel Rendering of Large Time-Varying Volume Data

    NASA Technical Reports Server (NTRS)

    Garbutt, Alexander E.

    2005-01-01

    Interactive visualization of large time-varying 3D volume datasets has been and still is a great challenge to the modem computational world. It stretches the limits of the memory capacity, the disk space, the network bandwidth and the CPU speed of a conventional computer. In this SURF project, we propose to develop a parallel volume rendering program on SGI's Prism, a cluster computer equipped with state-of-the-art graphic hardware. The proposed program combines both parallel computing and hardware rendering in order to achieve an interactive rendering rate. We use 3D texture mapping and a hardware shader to implement 3D volume rendering on each workstation. We use SGI's VisServer to enable remote rendering using Prism's graphic hardware. And last, we will integrate this new program with ParVox, a parallel distributed visualization system developed at JPL. At the end of the project, we Will demonstrate remote interactive visualization using this new hardware volume renderer on JPL's Prism System using a time-varying dataset from selected JPL applications.

  16. Long-term Recording of Night-Time Respiratory Symptoms in Patients with Stable COPD II-IV.

    PubMed

    Krönig, Johannes; Hildebrandt, Olaf; Weissflog, Andreas; Cassel, Werner; Gross, Volker; Sohrabi, Keywan; Fischer, Patrick; Koehler, Ulrich

    2017-10-01

    Night-time respiratory symptoms have a considerable impact on sleep and life quality in patients with chronic obstructive pulmonary disease (COPD). Lack of awareness of night-time symptoms can lead to worsened COPD control. Automated long-term monitoring of respiratory symptoms with LEOSound enables assessment of nocturnal wheezing and cough. In this observational study we investigated the prevalence and severity of cough and wheezing in patients with stable COPD [Global Initiative for Chronic Obstructive Lung Disease (GOLD) II-IV] disease for two consecutive nights with the LEOSound system. 48 patients (30 males, 63%) were eligible for inclusion, median age was 67 years, and body mass index (BMI) was 25.3 kg/m(2). In 15 out of 48 patients (31%), we found wheezing periods for at least 10-minute duration. Wheezing periods >30 minutes were monitored in seven patients and wheezing periods >60 minutes were monitored in three patients. The maximum duration of wheezing was 470 minutes in one patient with COPD II. The median wheezing rate differed between the COPD stages and between active and non-active smokers. Cough was found in 42 patients (87.5%) with a range of 1-326 events. The cough-period-index in night one was 0.83 n/hour (P25:0.33||P75: 2.04) and night two 0.97 n/hour (P25:0.25||P75: 1.9). Most of the cough events were non-productive with a median of 0.86. Night-time symptoms are common in COPD patients. LEOSound offers an opportunity to evaluate objectively night-time symptoms like wheezing and cough in patients with COPD which remain otherwise unnoticed. We found a high incidence of night-time wheezing in these patients, which was related to persistant smoking.

  17. Impact of Consolidation Radiation Therapy in Stage III-IV Diffuse Large B-cell Lymphoma With Negative Post-Chemotherapy Radiologic Imaging

    SciTech Connect

    Dorth, Jennifer A.; Prosnitz, Leonard R.; Broadwater, Gloria; Diehl, Louis F.; Beaven, Anne W.; Coleman, R. Edward; Kelsey, Chris R.

    2012-11-01

    Purpose: While consolidation radiation therapy (i.e., RT administered after chemotherapy) is routine treatment for patients with early-stage diffuse large B-cell lymphoma (DLBCL), the role of consolidation RT in stage III-IV DLBCL is controversial. Methods and Materials: Cases of patients with stage III-IV DLBCL treated from 1991 to 2009 at Duke University, who achieved a complete response to chemotherapy were reviewed. Clinical outcomes were calculated using the Kaplan-Meier method and were compared between patients who did and did not receive RT, using the log-rank test. A multivariate analysis was performed using Cox proportional hazards model. Results: Seventy-nine patients were identified. Chemotherapy (median, 6 cycles) consisted of anti-CD20 antibody rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP; 65%); cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP; 22%); or other (13%). Post-chemotherapy imaging consisted of positron emission tomography (PET)/computed tomography (CT) (73%); gallium with CT (14%); or CT only (13%). Consolidation RT (median, 25 Gy) was given to involved sites of disease in 38 (48%) patients. Receipt of consolidation RT was associated with improved in-field control (92% vs. 69%, respectively, p = 0.028) and event-free survival (85% vs. 65%, respectively, p = 0.014) but no difference in overall survival (85% vs. 78%, respectively, p = 0.15) when compared to patients who did not receive consolidation RT. On multivariate analysis, no RT was predictive of increased risk of in-field failure (hazard ratio [HR], 8.01, p = 0.014) and worse event-free survival (HR, 4.3, p = 0.014). Conclusions: Patients with stage III-IV DLBCL who achieve negative post-chemotherapy imaging have improved in-field control and event-free survival with low-dose consolidation RT.

  18. Large time behavior of solutions for hyperbolic balance laws

    NASA Astrophysics Data System (ADS)

    Yu, Hongjun

    2016-11-01

    We study the existence and the large time behavior of global solutions to the initial value problem for hyperbolic balance laws in n space dimensions with n ≥ 3 admitting an entropy and satisfying the stable condition. We first construct global existence of the solutions to such a system around a steady state if the initial energy is small enough. Then we show that k-order derivatives of these solutions approach a constant state in the Lp-norm at a rate O (t -1/2 (k + ρ +n/2 - n/p)) with p ∈ [ 2 , ∞ ] and ρ ∈ [ 0 ,n/2 ] provided that initially ‖z0 ‖ B˙2, ∞ - ρ < ∞, where B˙2, ∞ - ρ is a homogeneous Besov space. These decay results do not impose an additional smallness assumption on Lp norm of the initial data and we thus improve the results in [3,19]. We also show faster decay results in the sense that if ‖ Pz0 ‖ B˙2, ∞ - ρ +‖ (I - P)z0 ‖ B˙2, ∞ - ρ + 1 < ∞ with ρ ∈ (n/2 ,n + 2/2 ], k-order derivatives of the solutions approach a constant state in the Lp-norm at a rate O (t -1/2 (k + ρ + 1 +n/2 - n/p )).

  19. The Large Binocular Telescope: binocular all the time

    NASA Astrophysics Data System (ADS)

    Hill, J. M.; Ashby, D. S.; Brynnel, J. G.; Christou, J. C.; Little, John K.; Summers, D. M.; Veillet, C.; Wagner, R. M.

    2014-07-01

    The Large Binocular Telescope Observatory is a collaboration between institutions in Arizona, Germany, Italy, Indiana, Minnesota, Ohio and Virginia. The telescope uses two 8.4-m diameter primary mirrors mounted sideby- side on the same AZ-EL mount to produce a collecting area equivalent to an 11.8-meter aperture. Many science observations collect the light from the two sides separately. With the arrival of the second copy of the near-infrared spectrometer and the second copy of the optical spectrometer, the telescope is observing with both apertures a significant fraction of the time. The light from the two primary mirrors can be combined to produce phased-array imaging of an extended field. This coherent imaging along with adaptive optics gives the telescope the diffraction-limited resolution of a 22.65-meter telescope. Adaptive optics loops are routinely closed with natural stars on both sides of the telescope for combined beam observations. Twin laser guide star constellations have recently been installed for ground layer adaptive optics observations. Commissioning of new instruments and focal stations for high resolution spectroscopy and near-infrared phased-array imaging is underway.

  20. Oceanic time variability near a large scale topographic circulation

    NASA Astrophysics Data System (ADS)

    Bigorre, Sebastien; Dewar, William K.

    The oceanic circulation around a large scale topographic anomaly is studied using a numerical quasigeostrophic (QG) model. This simulation bears important similarities to a real ocean case, the Zapiola Anticyclone (ZA). The simple physics of the model allow the identification of two controlling parameters of the topographic circulation: bottom friction and eddy diffusivity. The role of these parameters was predicted in the theory proposed by Dewar [Dewar, W.K., 1998. Topography and barotropic transport control by bottom friction. J. Mar. Res. 56, 295-328] for the mean flow. This paper focuses on the time variability of the simulated circulation. The topography energizes the low frequency band, due to variations of the topographic circulation and its collapses. A local mode varies the amplitude of the topographic circulation and is related to the eddy field activity. The model shows that the trapped circulation can be shed away from the topography due to an increased sensitivity to the background flow perturbations. In the mesoscale band, a mode one anticyclonic wave also appears. We compare these features with similar observations in the Zapiola region. The location and strength of the ZA raise the question of its role in the mean regional oceanic circulation. This work suggests that its variability on a variety of temporal scales may also be of importance.

  1. Real-time vibration compensation for large telescopes

    NASA Astrophysics Data System (ADS)

    Böhm, M.; Pott, J.-U.; Sawodny, O.; Herbst, T.; Kürster, M.

    2014-08-01

    We compare different strategies for minimizing the effects of telescope vibrations to the differential piston (optical pathway difference) for the Near-InfraRed/Visible Adaptive Camera and INterferometer for Astronomy (LINC-NIRVANA) at the Large Binocular Telescope (LBT) using an accelerometer feedforward compensation approach. We summarize, why this technology is important for LINC-NIRVANA, and also for future telescopes and already existing instruments. The main objective is outlining a solution for the estimation problem in general and its specifics at the LBT. Emphasis is put on realistic evaluation of the used algorithms in the laboratory, such that predictions for the expected performance at the LBT can be made. Model-based estimation and broad-band filtering techniques can be used to solve the estimation task, and the differences are discussed. Simulation results and measurements are shown to motivate our choice of the estimation algorithm for LINC-NIRVANA. The laboratory setup is aimed at imitating the vibration behaviour at the LBT in general, and the M2 as main contributor in particular. For our measurements, we introduce a disturbance time series which has a frequency spectrum comparable to what can be measured at the LBT on a typical night. The controllers' ability to suppress vibrations in the critical frequency range of 8-60 Hz is demonstrated. The experimental results are promising, indicating the ability to suppress differential piston induced by telescope vibrations by a factor of about 5 (rms), which is significantly better than any currently commissioned system.

  2. Thermodynamics and kinetics of large-time-step molecular dynamics.

    PubMed

    Rao, Francesco; Spichty, Martin

    2012-02-15

    Molecular dynamics (MD) simulations provide essential information about the thermodynamics and kinetics of proteins. Technological advances in both hardware and algorithms have seen this method accessing timescales that used to be unreachable only few years ago. The quest to simulate slow, biologically relevant macromolecular conformational changes, is still open. Here, we present an approximate approach to increase the speed of MD simulations by a factor of ∼4.5. This is achieved by using a large integration time step of 7 fs, in combination with frozen covalent bonds and look-up tables for nonbonded interactions of the solvent. Extensive atomistic MD simulations for a flexible peptide in water show that the approach reproduces the peptide's equilibrium conformational changes, preserving the essential properties of both thermodynamics and kinetics. Comparison of this approximate method with state-of-the-art implicit solvation simulations indicates that the former provides a better description of the underlying free-energy surface. Finally, simulations of a 33-residue peptide show that these fast MD settings are readily applicable to investigate biologically relevant systems.

  3. VAC Therapy in Large Infected Sacral Pressure Ulcer Grade IV-Can Be an Alternative to Flap Reconstruction?

    PubMed

    Batra, R K; Aseeja, Veena

    2014-04-01

    Vacuum-assisted closure (VAC) therapy is a new entrant in wound care after growth factors and alginate or hydrocolloid dressing, in the treatment of pressure ulcers. We have been using this technique for diabetic foot ulcers. A young nondiabetic man presented with a large sacral bed sore after high doses of ionotropes in an intensive care unit for treating severe hypotension. His wound was debrided, and instead of flap surgery in such infected wound, he was treated with VAC therapy. The complete wound healing was achieved in 6 weeks and at half the cost of flap surgery. Moreover, the chances of flap failure and its related complications were eliminated.

  4. Large Time Projection Chambers for Rare Event Detection

    SciTech Connect

    Heffner, M

    2009-11-03

    The Time Projection Chamber (TPC) concept [add ref to TPC section] has been applied to many projects outside of particle physics and the accelerator based experiments where it was initially developed. TPCs in non-accelerator particle physics experiments are principally focused on rare event detection (e.g. neutrino and darkmater experiments) and the physics of these experiments can place dramatically different constraints on the TPC design (only extensions to the traditional TPCs are discussed here). The drift gas, or liquid, is usually the target or matter under observation and due to very low signal rates a TPC with the largest active mass is desired. The large mass complicates particle tracking of short and sometimes very low energy particles. Other special design issues include, efficient light collection, background rejection, internal triggering and optimal energy resolution. Backgrounds from gamma-rays and neutrons are significant design issues in the construction of these TPCs. They are generally placed deep underground to shield from cosmogenic particles and surrounded with shielding to reduce radiation from the local surroundings. The construction materials have to be carefully screened for radiopurity as they are in close contact with the active mass and can be a signification source of background events. The TPC excels in reducing this internal background because the mass inside the fieldcage forms one monolithic volume from which fiducial cuts can be made ex post facto to isolate quiet drift mass, and can be circulated and purified to a very high level. Self shielding in these large mass systems can be significant and the effect improves with density. The liquid phase TPC can obtain a high density at low pressure which results in very good self-shielding and compact installation with a lightweight containment. The down sides are the need for cryogenics, slower charge drift, tracks shorter than the typical electron diffusion, lower energy resolution (e

  5. Large seals fabricated from small segments reduce procurement lead time

    NASA Technical Reports Server (NTRS)

    Daniels, C. M.; Hanes, V. D.

    1966-01-01

    Large diameter seals are fabricated from narrow strip stock welded in segments to form a complete ring. This technique could be used to reduce the cost of critical, large diameter seals in the heating and ventilating industry, petrochemical industry, and marine fabrication industry.

  6. Evaluation of a complex intervention to improve primary care prescribing: a phase IV segmented regression interrupted time series analysis.

    PubMed

    MacBride-Stewart, Sean; Marwick, Charis; Houston, Neil; Watt, Iain; Patton, Andrea; Guthrie, Bruce

    2017-05-01

    It is uncertain whether improvements in primary care high-risk prescribing seen in research trials can be realised in the real-world setting. To evaluate the impact of a 1-year system-wide phase IV prescribing safety improvement initiative, which included education, feedback, support to identify patients to review, and small financial incentives. An interrupted time series analysis of targeted high-risk prescribing in all 56 general practices in NHS Forth Valley, Scotland, was performed. In 2013-2014, this focused on high-risk non-steroidal anti-inflammatory drugs (NSAIDs) in older people and NSAIDs with oral anticoagulants; in 2014-2015, it focused on antipsychotics in older people. The primary analysis used segmented regression analysis to estimate impact at the end of the intervention, and 12 months later. The secondary analysis used difference-in-difference methods to compare Forth Valley changes with those in NHS Greater Glasgow and Clyde (GGC). In the primary analysis, downward trends for all three NSAID measures that were existent before the intervention statistically significantly steepened following implementation of the intervention. At the end of the intervention period, 1221 fewer patients than expected were prescribed a high-risk NSAID. In contrast, antipsychotic prescribing in older people increased slowly over time, with no intervention-associated change. In the secondary analysis, reductions at the end of the intervention period in all three NSAID measures were statistically significantly greater in NHS Forth Valley than in NHS GGC, but only significantly greater for two of these measures 12 months after the intervention finished. There were substantial and sustained reductions in the high-risk prescribing of NSAIDs, although with some waning of effect 12 months after the intervention ceased. The same intervention had no effect on antipsychotic prescribing in older people. © British Journal of General Practice 2017.

  7. A new class of large band gap quantum spin hall insulators: 2D fluorinated group-IV binary compounds

    NASA Astrophysics Data System (ADS)

    Padilha, J. E.; Pontes, R. B.; Schmidt, T. M.; Miwa, R. H.; Fazzio, A.

    2016-05-01

    We predict a new class of large band gap quantum spin Hall insulators, the fluorinated PbX (X = C, Si, Ge and Sn) compounds, that are mechanically stable two-dimensional materials. Based on first principles calculations we find that, while the PbX systems are not topological insulators, all fluorinated PbX (PbXF2) compounds are 2D topological insulators. The quantum spin Hall insulating phase was confirmed by the explicitly calculation of the Z2 invariant. In addition we performed a thorough investigation of the role played by the (i) fluorine saturation, (ii) crystal field, and (iii) spin-orbital coupling in PbXF2. By considering nanoribbon structures, we verify the appearance of a pair of topologically protected Dirac-like edge states connecting the conduction and valence bands. The insulating phase which is a result of the spin orbit interaction, reveals that this new class of two dimensional materials present exceptional nontrivial band gaps, reaching values up to 0.99 eV at the Γ point, and an indirect band gap of 0.77 eV. The topological phase is arisen without any external field, making this system promising for nanoscale applications, using topological properties.

  8. A new class of large band gap quantum spin hall insulators: 2D fluorinated group-IV binary compounds

    PubMed Central

    Padilha, J. E.; Pontes, R. B.; Schmidt, T. M.; Miwa, R. H.; Fazzio, A.

    2016-01-01

    We predict a new class of large band gap quantum spin Hall insulators, the fluorinated PbX (X = C, Si, Ge and Sn) compounds, that are mechanically stable two-dimensional materials. Based on first principles calculations we find that, while the PbX systems are not topological insulators, all fluorinated PbX (PbXF2) compounds are 2D topological insulators. The quantum spin Hall insulating phase was confirmed by the explicitly calculation of the Z2 invariant. In addition we performed a thorough investigation of the role played by the (i) fluorine saturation, (ii) crystal field, and (iii) spin-orbital coupling in PbXF2. By considering nanoribbon structures, we verify the appearance of a pair of topologically protected Dirac-like edge states connecting the conduction and valence bands. The insulating phase which is a result of the spin orbit interaction, reveals that this new class of two dimensional materials present exceptional nontrivial band gaps, reaching values up to 0.99 eV at the Γ point, and an indirect band gap of 0.77 eV. The topological phase is arisen without any external field, making this system promising for nanoscale applications, using topological properties. PMID:27212604

  9. Damped Lyman-alpha absorption by disk galaxies with large redshifts. IV - More intermediate-resolution spectroscopy

    NASA Technical Reports Server (NTRS)

    Wolfe, Arthur M.; Turnshek, David A.; Lanzetta, Kenneth M.; Lu, Limin

    1993-01-01

    Intermediate-resolution spectra of six QSOs exhibiting seven Ly-alpha absorption troughs that are candidates for damped Ly-alpha absorption lines are presented. The metal content of the confirmed damped systems is investigated by examining the metal-line velocity profiles, and by performing curve-of-growth analyses for four of the six confirmed damped systems. The low-ionization lines associated with the z(metals) = 2.0399 damped system toward Q0458-020 have velocity widths up to 10 times wider than the width of the 21-cm absorption feature found at the same redshift. Since the 21-cm absorption arises in a low velocity dispersion layer of H I that extends more than 8/h kpc transverse to the line of sight, the H I absorption cannot arise from the same clouds responsible for the bulk of the metal-line absorption. This is strong evidence for a two-component model consisting of high column density 'quiescent' gas which gives rise to damped Ly-alpha and 21-cm absorption, and low column density 'turbulent' gas which dominates equivalent widths of saturated metal lines.

  10. Development of a new real-time method for measuring S(IV) in cloud water using a counter-flow virtual impactor

    NASA Astrophysics Data System (ADS)

    Dixon, Roy W.; Charlson, Robert J.

    1994-07-01

    A new method of analysis for S(IV) is described incorporating a counter-flow virtual impactor for collection and evaporation of cloud droplets with an SO2 analyzer. This technique allows analysis of aqueous S(IV) concentration in real-time and overcomes some sampling or analysis problems of conventional sampling with bulk cloud water collectors and wet chemical analysis methods. The technique is demonstrated by the correlated responses of the S(IV) instrument and instruments measuring physical properties of clouds while passing in and out of clouds. Measured aqueous S(IV) concentrations ranged from the detection limit (0.1nmol per m3 of air) to 1.8nmol m-3 in clouds in Ohio. S(IV) molar concentrations (moles/l of cloud water) were not calculable from these measurements, but can be calculated when a measurement of the liquid water content of the collected cloud water is made simultaneously.

  11. Real-Time Measurements of Sediment Modification by Large Macrofauna

    DTIC Science & Technology

    2009-01-01

    2. Fluorescein distribution at time 0, 30, and 60 min (left to right) from multiple injections to a depth of 10 cm in an ant farm aquarium ...the University of Georgia , specifically looking at the interactions among benthic infauna, impacts on sediment properties, and spatial dimensions of

  12. Large-memory real-time multichannel multiplexed pattern recognition

    NASA Astrophysics Data System (ADS)

    Gregory, D. A.; Liu, H. K.

    1984-12-01

    The principle and experimental design of a real-time multichannel multiplexed optical pattern recognition system via use of a 25-focus dichromated gelatin holographic lens (hololens) are described. Each of the 25 foci of the hololens may have a storage and matched filtering capability approaching that of a single-lens correlator. If the space-bandwidth product of an input image is limited, as is true in most practical cases, the 25-focus hololens system has 25 times the capability of a single lens. Experimental results have shown that the interfilter noise is not serious. The system has already demonstrated the storage and recognition of over 70 matched filters - which is a larger capacity than any optical pattern recognition system reported to date.

  13. Large-memory real-time multichannel multiplexed pattern recognition

    NASA Technical Reports Server (NTRS)

    Gregory, D. A.; Liu, H. K.

    1984-01-01

    The principle and experimental design of a real-time multichannel multiplexed optical pattern recognition system via use of a 25-focus dichromated gelatin holographic lens (hololens) are described. Each of the 25 foci of the hololens may have a storage and matched filtering capability approaching that of a single-lens correlator. If the space-bandwidth product of an input image is limited, as is true in most practical cases, the 25-focus hololens system has 25 times the capability of a single lens. Experimental results have shown that the interfilter noise is not serious. The system has already demonstrated the storage and recognition of over 70 matched filters - which is a larger capacity than any optical pattern recognition system reported to date.

  14. Large-memory real-time multichannel multiplexed pattern recognition

    NASA Technical Reports Server (NTRS)

    Gregory, D. A.; Liu, H. K.

    1984-01-01

    The principle and experimental design of a real-time multichannel multiplexed optical pattern recognition system via use of a 25-focus dichromated gelatin holographic lens (hololens) are described. Each of the 25 foci of the hololens may have a storage and matched filtering capability approaching that of a single-lens correlator. If the space-bandwidth product of an input image is limited, as is true in most practical cases, the 25-focus hololens system has 25 times the capability of a single lens. Experimental results have shown that the interfilter noise is not serious. The system has already demonstrated the storage and recognition of over 70 matched filters - which is a larger capacity than any optical pattern recognition system reported to date.

  15. The PLATO IV Architecture.

    ERIC Educational Resources Information Center

    Stifle, Jack

    The PLATO IV computer-based instructional system consists of a large scale centrally located CDC 6400 computer and a large number of remote student terminals. This is a brief and general description of the proposed input/output hardware necessary to interface the student terminals with the computer's central processing unit (CPU) using available…

  16. Division Iv: Stars

    NASA Astrophysics Data System (ADS)

    Corbally, Christopher; D'Antona, Francesca; Spite, Monique; Asplund, Martin; Charbonnel, Corinne; Docobo, Jose Angel; Gray, Richard O.; Piskunov, Nikolai E.

    2012-04-01

    This Division IV was started on a trial basis at the General Assembly in The Hague 1994 and was formally accepted at the Kyoto General Assembly in 1997. Its broad coverage of ``Stars'' is reflected in its relatively large number of Commissions and so of members (1266 in late 2011). Its kindred Division V, ``Variable Stars'', has the same history of its beginning. The thinking at the time was to achieve some kind of balance between the number of members in each of the 12 Divisions. Amid the current discussion of reorganizing the number of Divisions into a more compact form it seems advisable to make this numerical balance less of an issue than the rationalization of the scientific coverage of each Division, so providing more effective interaction within a particular field of astronomy. After all, every star is variable to a certain degree and such variability is becoming an ever more powerful tool to understand the characteristics of every kind of normal and peculiar star. So we may expect, after hearing the reactions of members, that in the restructuring a single Division will result from the current Divisions IV and V.

  17. Asteroids IV

    NASA Astrophysics Data System (ADS)

    Michel, Patrick; DeMeo, Francesca E.; Bottke, William F.

    . Asteroids, like planets, are driven by a great variety of both dynamical and physical mechanisms. In fact, images sent back by space missions show a collection of small worlds whose characteristics seem designed to overthrow our preconceived notions. Given their wide range of sizes and surface compositions, it is clear that many formed in very different places and at different times within the solar nebula. These characteristics make them an exciting challenge for researchers who crave complex problems. The return of samples from these bodies may ultimately be needed to provide us with solutions. In the book Asteroids IV, the editors and authors have taken major strides in the long journey toward a much deeper understanding of our fascinating planetary ancestors. This book reviews major advances in 43 chapters that have been written and reviewed by a team of more than 200 international authorities in asteroids. It is aimed to be as comprehensive as possible while also remaining accessible to students and researchers who are interested in learning about these small but nonetheless important worlds. We hope this volume will serve as a leading reference on the topic of asteroids for the decade to come. We are deeply indebted to the many authors and referees for their tremendous efforts in helping us create Asteroids IV. We also thank the members of the Asteroids IV scientific organizing committee for helping us shape the structure and content of the book. The conference associated with the book, "Asteroids Comets Meteors 2014" held June 30-July 4, 2014, in Helsinki, Finland, did an outstanding job of demonstrating how much progress we have made in the field over the last decade. We are extremely grateful to our host Karri Muinonnen and his team. The editors are also grateful to the Asteroids IV production staff, namely Renée Dotson and her colleagues at the Lunar and Planetary Institute, for their efforts, their invaluable assistance, and their enthusiasm; they made life as

  18. Large-time evolution of an electron in photon bath

    SciTech Connect

    Kazakov, Kirill A.; Nikitin, Vladimir V.

    2012-12-15

    The problem of infrared divergence of the effective electromagnetic field produced by elementary charges is revisited using the model of an electron freely evolving in a photon bath. It is shown that for any finite travel time, the effective field of the electron is infrared-finite, and that at each order of perturbation theory the radiative contributions grow unboundedly with time. Using the Schwinger-Keldysh formalism, factorization of divergent contributions in multi-loop diagrams is proved, and summation of the resulting infinite series is performed. It is found that despite the unbounded growth of individual contributions to the effective field, their sum is bounded, tending to zero in the limit of infinite travel time. It is concluded that the physical meaning of infrared singularity in the effective field is the existence of a peculiar irreversible spreading of electric charges, caused by their interaction with the electromagnetic field. This spreading originates from the quantum electromagnetic fluctuations, rather than the electron-photon scattering, and exists in vacuum as well as at finite temperatures. It shows itself in a damping of the off-diagonal elements of the momentum-space density matrix of electron, but does not affect its momentum probability distribution. This effect is discussed in terms of thermalization of the electron state, and the asymptotic growth of its quantum entropy is determined. Relationship of the obtained results to the Bloch-Nordsieck theorem is established and considered from the standpoint of measurability of the electromagnetic field. The effect of irreversible spreading on the electron diffraction in the classic two-slit experiment is determined, and is shown to be detectable in principle by modern devices already at room temperature. - Highlights: Black-Right-Pointing-Pointer Infrared finiteness of the effective electromagnetic field of a free electron is proved. Black-Right-Pointing-Pointer Quantum radiative effects

  19. Times to extinction for small populations of large birds.

    PubMed

    Pimm, S L; Diamond, J; Reed, T M; Russell, G J; Verner, J

    1993-11-15

    A major practical problem in conservation biology is to predict the survival times-"lifetimes"-for small populations under alternative proposed management regimes. Examples in the United States include the 'Alala (Hawaiian Crow; Corvus hawaiiensis) and Northern Spotted Owl (Strix occidentalis caurina). To guide such decisions, we analyze counts of all crow, owl, and hawk species in the most complete available data set: counts of bird breeding pairs on 14 European islands censused for 29-66 consecutive years. The data set yielded 129 records for analysis. We define the population ceiling as the highest number of breeding pairs observed from colonization to extinction, within a consecutive series of counts for a given species on a given island. The resulting distributions of population lifetimes as a function of population size prove to be highly skewed: most small populations disappear quickly, but a few last for a long time. Median (i.e., 50th percentile) lifetimes are calculated as only 1-5 yr for hawk, owl, and crow populations with ceilings of one or two breeding pairs. As expected if demographic accidents are the main cause of extinction for small populations, lifetimes rise by a factor of 3-4 for each additional pair up to three pairs. They rise more slowly thereafter. These observations suggest that lifetimes of the 'Alala (now reduced to about three pairs in the wild), and of populations of Northern Spotted Owl in the smallest forest fragments, will be short unless active management is implemented.

  20. Millisecond coherence time in a tunable molecular electronic spin qubit [An unprecedented coherence time in a tunable molecular V(IV) electronic spin qubit

    DOE PAGES

    Zadrozny, Joseph M.; Niklas, Jens; Poluektov, Oleg G.; ...

    2015-12-02

    Here, quantum information processing (QIP) could revolutionize areas ranging from chemical modeling to cryptography. One key figure of merit for the smallest unit for QIP, the qubit, is the coherence time (T2), which establishes the lifetime for the qubit. Transition metal complexes offer tremendous potential as tunable qubits, yet their development is hampered by the absence of synthetic design principles to achieve a long T2. We harnessed molecular design to create a series of qubits, (Ph4P)2[V(C8S8)3] (1), (Ph4P)2[V(β-C3S5)3] (2), (Ph4P)2[V(α-C3S5)3] (3), and (Ph4P)2[V(C3S4O)3] (4), with T2s of 1–4 μs at 80 K in protiated and deuterated environments. Crucially, through chemicalmore » tuning of nuclear spin content in the vanadium(IV) environment we realized a T2 of ~1 ms for the species (d20-Ph4P)2[V(C8S8)3] in CS2, a value that surpasses the coordination complex record by an order of magnitude. This value even eclipses some prominent solid-state qubits. Electrochemical and continuous wave electron paramagnetic resonance (EPR) data reveal variation in the electronic influence of the ligands on the metal ion across 1–4. However, pulsed measurements indicate that the most important influence on decoherence is nuclear spins in the protiated and deuterated solvents utilized herein. Our results illuminate a path forward in synthetic design principles, which should unite CS2 solubility with nuclear spin free ligand fields to develop a new generation of molecular qubits.« less

  1. Time course of anti-SL-IV immunoglobulin G antibodies in patients with tuberculosis and tuberculosis-associated AIDS.

    PubMed Central

    Martin-Casabona, N; Gonzalez Fuente, T; Papa, F; Rosselló Urgell, J; Vidal Plá, R; Codina Grau, G; Ruiz Camps, I

    1992-01-01

    Immunoglobulin G (IgG) and IgM antibodies against the SL-IV antigen of Mycobacterium tuberculosis in the sera of patients with tuberculosis with negative serology for human immunodeficiency virus (HIV) infection (TB group; n = 97), patients with tuberculosis with positive serology for HIV infection (TB-HIV group; n = 59), and healthy controls (n = 289) were determined by enzyme-linked immunosorbent assay. All sera were obtained at the onset of tuberculosis, i.e., when clinical symptoms appeared. Clinical specimens were collected and cultured for the isolation of M. tuberculosis, and treatment with antituberculous drugs was started. Sera were also obtained from patients in the TB group at fixed intervals during treatment; sera were available from 13 patients in the TB-HIV group before the onset of tuberculosis. The best specificity and positive predictive values were obtained with the IgG assays. In the IgG assays at specificities above 96.0%, the sensitivities of the tests were 45.3 and 72.8% for the TB and TB-HIV groups, respectively, and the sensitivity was 51.9% when data from both groups were combined for analysis. For the TB group, results of this study indicated that the levels of IgG antibodies remain high during treatment. Thus, repetitive serological assays may not be useful for treatment follow-up. In the TB-HIV group, 12 of 13 patients had IgG-specific antibodies against the SL-IV antigen between 1 and 30 months before the onset of tuberculosis, so we suggest that the IgG antibody assay against SL-IV may be helpful for identifying tuberculosis in patients infected with HIV. PMID:1583105

  2. Slow magnetic relaxation induced by a large transverse zero-field splitting in a Mn(II)Re(IV)(CN)2 single-chain magnet.

    PubMed

    Feng, Xiaowen; Liu, Junjie; Harris, T David; Hill, Stephen; Long, Jeffrey R

    2012-05-02

    The model compounds (NBu(4))(2)[ReCl(4)(CN)(2)] (1), (DMF)(4)ZnReCl(4)(CN)(2) (2), and [(PY5Me(2))(2)Mn(2)ReCl(4)(CN)(2)](PF(6))(2) (3) have been synthesized to probe the origin of the magnetic anisotropy barrier in the one-dimensional coordination solid (DMF)(4)MnReCl(4)(CN)(2) (4). High-field electron paramagnetic resonance spectroscopy reveals the presence of an easy-plane anisotropy (D > 0) with a significant transverse component, E, in compounds 1-3. These findings indicate that the onset of one-dimensional spin correlations within the chain compound 4 leads to a suppression of quantum tunneling of the magnetization within the easy plane, resulting in magnetic bistability and slow relaxation behavior. Within this picture, it is the transverse E term associated with the Re(IV) centers that determines the easy axis and the anisotropy energy scale associated with the relaxation barrier. The results demonstrate for the first time that slow magnetic relaxation can be achieved through optimization of the transverse anisotropy associated with magnetic ions that possess easy-plane anisotropy, thus providing a new direction in the design of single-molecule and single-chain magnets. © 2012 American Chemical Society

  3. Welding IV.

    ERIC Educational Resources Information Center

    Allegheny County Community Coll., Pittsburgh, PA.

    Instructional objectives and performance requirements are outlined in this course guide for Welding IV, a competency-based course in advanced arc welding offered at the Community College of Allegheny County to provide students with proficiency in: (1) single vee groove welding using code specifications established by the American Welding Society…

  4. Welding IV.

    ERIC Educational Resources Information Center

    Allegheny County Community Coll., Pittsburgh, PA.

    Instructional objectives and performance requirements are outlined in this course guide for Welding IV, a competency-based course in advanced arc welding offered at the Community College of Allegheny County to provide students with proficiency in: (1) single vee groove welding using code specifications established by the American Welding Society…

  5. Importance of timing of post-contrast MRI in rheumatoid arthritis: what happens during the first 60 minutes after IV gadolinium-DTPA?

    PubMed Central

    Ostergaard, M; Klarlund, M

    2001-01-01

    BACKGROUND—Volumes of inflamed synovial membrane determined by magnetic resonance imaging (MRI) are closely related to histopathological synovitis and may predict erosive progression in rheumatoid arthritis (RA). However, after IV injection, leakage of MRI contrast from the synovium gradually compromises the differentiation of synovium from joint fluid.
OBJECTIVE—To determine the time period after IV MRI contrast (gadolinium-DTPA (Gd)) injection in which synovial membrane volume determination is reliable.
METHODS—MRI of five RA knees with clinical synovitis was carried out, with axial, T1 weighted, spin echo images before IV Gd injection and every 1.75 minutes for 60 minutes post-Gd. By a semiautomated "signal enhancement threshold" method, including voxels with >35% or >45% relative post-Gd enhancement, synovial membrane volumes were estimated at each time point. At 4.25 minutes post-Gd, volumes were also determined by a more accurate but time consuming "manual method".
RESULTS—The initially observed synovium-effusion borderline remained clearly visible, and on the same location, within at least the initial 11 minutes post-Gd (that is, within the normal time frame of post-Gd imaging in RA) but started blurring and moving centripetally thereafter. Compared with volumes at all other time points, synovial membrane volumes at 0.75 and 2.50 minutes post-Gd were significantly lower (Wilcoxon-Pratt), suggesting that some synovial membrane areas had not yet exceeded the enhancement threshold. Thereafter, the measured volumes remained practically unchanged.
CONCLUSION—This study suggests that MR image acquisition in arthritic knee joints should be performed within the initial approximately 10 minutes after gadolinium contrast injection to achieve the most accurate distinction between synovium and joint fluid but that small time variations are not of major importance to the measured synovial membrane volumes.

 PMID:11602477

  6. Large-time behavior of solutions to the inflow problem of full compressible Navier-Stokes equations with large perturbation

    NASA Astrophysics Data System (ADS)

    Hong, Hakho; Wang, Teng

    2017-08-01

    In this paper, we investigate the one-dimensional motion of compressible viscous and heat-conductive fluid on the half line \\renewcommand{\\b}β \\renewcommand{\\i}∞ {\\boldsymbol R}_+=(0, +∞) . The large-time behavior of the superposition of the transonic (or degenerate) boundary layer solution, 1-rarefaction wave, 2-viscous contact wave and 3-rarefaction wave is established for the inflow problem of full compressible Navier-Stokes system under a large initial perturbation for any adiabatic exponent \

  7. Interaction forces between red cells agglutinated by antibody. IV. Time and force dependence of break-up.

    PubMed Central

    Tees, D. F.; Coenen, O.; Goldsmith, H. L.

    1993-01-01

    We report on an extension of a previously described method to measure the hydrodynamic force to separate doublets of fixed, sphered and swollen red cells cross-linked by antibody (S. P. Tha, J. Shuster, and H. L. Goldsmith. 1986. Biophys. J. 50:1117-1126). With a traveling microtube apparatus, doublets are tracked and videotaped in a slowly accelerating Poiseuille flow in 150-microns-diameter tubes, and the hydrodynamic normal force at break-up, Fn, is computed from the measured doublet velocity and radial position. Previous results showed a large range of Fn, the mean of which increased with [antiserum], and an absence of clustering at discrete values of Fn. Since it was assumed that the cells separate the instant a critical force to break all crossbridges was reached, lack of clustering could have been due to the use of a polyclonal antiserum. We therefore studied the effect of monoclonal IgM or IgA antibody on the distribution of Fn. The results showed that the data are as scattered as ever, with Fn varying from 2 to 200 pN, and exhibit no evidence of clustering. However, the scatter in Fn could be due to the stochastic nature of intercellular bonds (E. Evans, D. Berk, and A. Leung. 1991a. Biophys. J. 59:838-848). We therefore studied the force dependence of the time to break-up under constant shear stress (Fn from 30 to 200 pN), both in Poiseuille and Couette flow, the latter by using a counter-rotating cone and plate rheoscope. When 280 doublets were rapidly accelerated in the traveling microtube and then allowed to coast in steady flow for up to 180 s, 91% survived into the constant force region; 16% of these broke up after time intervals, tP, of 2-30s. Of 340 doublets immediately exposed to constant shear in the rheoscope, 37% broke after time intervals, tc, from < 1 to 10 s. Thus, doublets do indeed break up under a constant shear stress, if given time. The average time to break-up decreased significantly with increasing force, while the fraction of

  8. Interaction forces between red cells agglutinated by antibody. IV. Time and force dependence of break-up.

    PubMed

    Tees, D F; Coenen, O; Goldsmith, H L

    1993-09-01

    We report on an extension of a previously described method to measure the hydrodynamic force to separate doublets of fixed, sphered and swollen red cells cross-linked by antibody (S. P. Tha, J. Shuster, and H. L. Goldsmith. 1986. Biophys. J. 50:1117-1126). With a traveling microtube apparatus, doublets are tracked and videotaped in a slowly accelerating Poiseuille flow in 150-microns-diameter tubes, and the hydrodynamic normal force at break-up, Fn, is computed from the measured doublet velocity and radial position. Previous results showed a large range of Fn, the mean of which increased with [antiserum], and an absence of clustering at discrete values of Fn. Since it was assumed that the cells separate the instant a critical force to break all crossbridges was reached, lack of clustering could have been due to the use of a polyclonal antiserum. We therefore studied the effect of monoclonal IgM or IgA antibody on the distribution of Fn. The results showed that the data are as scattered as ever, with Fn varying from 2 to 200 pN, and exhibit no evidence of clustering. However, the scatter in Fn could be due to the stochastic nature of intercellular bonds (E. Evans, D. Berk, and A. Leung. 1991a. Biophys. J. 59:838-848). We therefore studied the force dependence of the time to break-up under constant shear stress (Fn from 30 to 200 pN), both in Poiseuille and Couette flow, the latter by using a counter-rotating cone and plate rheoscope. When 280 doublets were rapidly accelerated in the traveling microtube and then allowed to coast in steady flow for up to 180 s, 91% survived into the constant force region; 16% of these broke up after time intervals, tP, of 2-30s. Of 340 doublets immediately exposed to constant shear in the rheoscope, 37% broke after time intervals, tc, from < 1 to 10 s. Thus, doublets do indeed break up under a constant shear stress, if given time. The average time to break-up decreased significantly with increasing force, while the fraction of

  9. IVS Organization

    NASA Technical Reports Server (NTRS)

    2004-01-01

    International VLBI Service (IVS) is an international collaboration of organizations which operate or support Very Long Baseline Interferometry (VLBI) components. The goals are: To provide a service to support geodetic, geophysical and astrometric research and operational activities. To promote research and development activities in all aspects of the geodetic and astrometric VLBI technique. To interact with the community of users of VLBI products and to integrate VLBI into a global Earth observing system.

  10. Observational properties of decameter type IV bursts

    NASA Astrophysics Data System (ADS)

    Melnik, Valentin; Brazhenko, Anatoly; Rucker, Helmut; Konovalenko, Alexander; Briand, Carine; Dorovskyy, Vladimir; Zarka, Philippe; Frantzusenko, Anatoly; Panchenko, Michael; Poedts, Stefan; Zaqarashvili, Teimuraz; Shergelashvili, Bidzina

    2013-04-01

    Oscillations of decameter type IV bursts were registered during observations of solar radio emission by UTR-2, URAN-2 and NDA in 2011-2012. Large majority of these bursts were accompanied by coronal mass ejections (CMEs), which were observed by SOHO and STEREO in the visible light. Only in some cases decameter type IV bursts were not associated with CMEs. The largest periods of oscillations P were some tens of minutes. There were some modes of long periods of oscillations simultaneously. Periods of oscillations in flux and in polarization profiles were close. Detailed properties of oscillations at different frequencies were analyzed on the example of two type IV bursts. One of them was observed on April 7, 2011 when a CME happened. Another one (August 1, 2011) was registered without any CME. The 7 April type IV burst had two periods in the frames 75-85 and 35-85 minutes. Interesting feature of these oscillations is decreasing periods with time. The observed decreasing rates dP/dt equaled 0.03-0.07. Concerning type IV burst observed on August 1, 2011 the period of its oscillations increases from 17 min. at 30 MHz to 44 min. at 10 MHz. Connection of type IV burst oscillations with oscillations of magnetic arches and CMEs at corresponding altitudes are discussed. The work is fulfilled in the frame of FP7 project "SOLSPANET".

  11. Use of a large time-compensated scintillation detector in neutron time-of-flight measurements

    DOEpatents

    Goodman, Charles D.

    1979-01-01

    A scintillator for neutron time-of-flight measurements is positioned at a desired angle with respect to the neutron beam, and as a function of the energy thereof, such that the sum of the transit times of the neutrons and photons in the scintillator are substantially independent of the points of scintillations within the scintillator. Extrapolated zero timing is employed rather than the usual constant fraction timing. As a result, a substantially larger scintillator can be employed that substantially increases the data rate and shortens the experiment time.

  12. Timing gamma-ray pulsars with the Fermi large area telescope: Timing noise and astrometry

    DOE PAGES

    Kerr, Matthew; Ray, P. S.; Johnston, S.; ...

    2015-11-25

    We have constructed timing solutions for 81 γ-ray pulsars covering more than five years of Fermi data. The sample includes 37 radio-quiet or radio-faint pulsars which cannot be timed with other telescopes. These timing solutions and the corresponding pulse times of arrival are prerequisites for further study, e.g., phase-resolved spectroscopy or searches for mode switches. Many γ-ray pulsars are strongly affected by timing noise (TN), and we present a new method for characterizing the noise process and mitigating its effects on other facets of the timing model. We present an analysis of TN over the population using a new metric for characterizing its strength and spectral shape, namely, its time-domain correlation. The dependence of the strength on ν andmore » $$\\dot{\

  13. A Taxometric Investigation of "DSM-IV" Major Depression in a Large Outpatient Sample: Interpretable Structural Results Depend on the Mode of Assessment

    ERIC Educational Resources Information Center

    Ruscio, John; Brown, Timothy A.; Ruscio, Ayelet Meron

    2009-01-01

    Most taxometric studies of depressive constructs have drawn indicators from self-report instruments that do not bear directly on the "Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV)" diagnostic construct of major depressive disorder (MDD). The present study examined the latent structure of MDD using indicator sets…

  14. Timing Gamma-ray Pulsars with the Fermi Large Area Telescope: Timing Noise and Astrometry

    NASA Astrophysics Data System (ADS)

    Kerr, M.; Ray, P. S.; Johnston, S.; Shannon, R. M.; Camilo, F.

    2015-12-01

    We have constructed timing solutions for 81 γ-ray pulsars covering more than five years of Fermi data. The sample includes 37 radio-quiet or radio-faint pulsars which cannot be timed with other telescopes. These timing solutions and the corresponding pulse times of arrival are prerequisites for further study, e.g., phase-resolved spectroscopy or searches for mode switches. Many γ-ray pulsars are strongly affected by timing noise (TN), and we present a new method for characterizing the noise process and mitigating its effects on other facets of the timing model. We present an analysis of TN over the population using a new metric for characterizing its strength and spectral shape, namely, its time-domain correlation. The dependence of the strength on ν and \\dot{ν } is in good agreement with previous studies. We find that noise process power spectra S(f) for unrecycled pulsars are steep, with strong correlations over our entire data set and spectral indices S(f)\\propto {f}-α of α ˜ 5-9. One possible explanation for these results is the occurrence of unmodeled, episodic “microglitches.” Finally, we show that our treatment of TN results in robust parameter estimation, and in particular we measure a precise timing position for each pulsar. We extensively validate our results with multi-wavelength astrometry, and using our updated position, we firmly identify the X-ray counterpart of PSR J1418-6058.

  15. Large-Alphabet Quantum Key Distribution Using Energy-Time Entangled Bipartite States

    NASA Astrophysics Data System (ADS)

    Ali-Khan, Irfan; Broadbent, Curtis J.; Howell, John C.

    2007-02-01

    We present a protocol for large-alphabet quantum key distribution (QKD) using energy-time entangled biphotons. Binned, high-resolution timing measurements are used to generate a large-alphabet key with over 10 bits of information per photon pair, albeit with large noise. QKD with 5% bit error rate is demonstrated with 4 bits of information per photon pair, where the security of the quantum channel is determined by the visibility of Franson interference fringes. The protocol is easily generalizable to even larger alphabets, and utilizes energy-time entanglement which is robust to transmission over large distances in fiber.

  16. Bibliographic Automation of Large Library Operations Using a Time-Sharing System: Phase I. Final Report.

    ERIC Educational Resources Information Center

    Epstein, A. H.; And Others

    The first phase of an ongoing library automation project at Stanford University is described. Project BALLOTS (Bibliographic Automation of Large Library Operations Using a Time-Sharing System) seeks to automate the acquisition and cataloging functions of a large library using an on-line time-sharing computer. The main objectives are to control…

  17. Kepler eclipsing binary stars. IV. Precise eclipse times for close binaries and identification of candidate three-body systems

    SciTech Connect

    Conroy, Kyle E.; Stassun, Keivan G.; Prša, Andrej; Orosz, Jerome A.; Welsh, William F.; Fabrycky, Daniel C.

    2014-02-01

    We present a catalog of precise eclipse times and analysis of third-body signals among 1279 close binaries in the latest Kepler Eclipsing Binary Catalog. For these short-period binaries, Kepler's 30 minute exposure time causes significant smearing of light curves. In addition, common astrophysical phenomena such as chromospheric activity, as well as imperfections in the light curve detrending process, can create systematic artifacts that may produce fictitious signals in the eclipse timings. We present a method to measure precise eclipse times in the presence of distorted light curves, such as in contact and near-contact binaries which exhibit continuously changing light levels in and out of eclipse. We identify 236 systems for which we find a timing variation signal compatible with the presence of a third body. These are modeled for the light travel time effect and the basic properties of the third body are derived. This study complements J. A. Orosz et al. (in preparation), which focuses on eclipse timing variations of longer period binaries with flat out-of-eclipse regions. Together, these two papers provide comprehensive eclipse timings for all binaries in the Kepler Eclipsing Binary Catalog, as an ongoing resource freely accessible online to the community.

  18. A Nationwide Survey on the Daily Screen Time of Iranian Children and Adolescents: The CASPIAN - IV Study

    PubMed Central

    Jari, Mohsen; Qorbani, Mostafa; Motlagh, Mohammad Esmaeil; Heshmat, Ramin; Ardalan, Gelayol; Kelishadi, Roya

    2014-01-01

    Background: Leisure time activity is an important life-style habit. This study aims to determine the screen time of a nationally representative sample of Iranian children and adolescents. Methods: This nationwide cross-sectional study was conducted as part of the fourth survey of a surveillance system. The participants consisted of 14880 students, with aged range from 6 to 18 years, living in 30 provinces in Iran. Screen time, i.e. the time spent on watching television (TV)/video and computer games during leisure time, was assessed by using the questionnaire of the Globasl Student Health Survey of the World Health Organization. Results: The study participants were 13486 school students (participation rate of 90.6%) with a mean age of 12. 47 (3.36) years. Overall, 75.6% of students were from urban and 24.4% from rural areas and 50.8% were boys respectively. Overall, 33.4% and 53% of students watched TV/video more than 2 h a day in their leisure time during school days and holidays, respectively. Likewise, 6.3% and 10.9% of students used computer more than 2 h a day in their leisure time during the school days and holidays, respectively. Overall, 47.1% of urban students and 24.2% of rural students used personal computer in their leisure time during the school days. The corresponding figures were 50.8% and 27.2% in weekends and holidays, respectively. Conclusions: The time spent on screen activities is long in a considerably high number of Iranian children and adolescents. It should be reduced by increasing the public awareness and by providing facilities for regular daily physic activity for students’ leisure times. PMID:24627751

  19. The Effect of Radiation Timing on Patients With High-Risk Features of Parameningeal Rhabdomyosarcoma: An Analysis of IRS-IV and D9803

    SciTech Connect

    Spalding, Aaron C.; Hawkins, Douglas S.; Anderson, James R.; Lyden, Elizabeth; Laurie, Fran; Wolden, Suzanne L.; Arndt, Carola A.S.; Michalski, Jeff M.

    2013-11-01

    Purpose: Radiation therapy remains an essential treatment for patients with parameningeal rhabdomyosarcoma (PMRMS), and early radiation therapy may improve local control for patients with intracranial extension (ICE). Methods and Materials: To address the role of radiation therapy timing in PMRMS in the current era, we reviewed the outcome from 2 recent clinical trials for intermediate-risk RMS: Intergroup Rhabdomyosarcoma Study (IRS)-IV and Children's Oncology Group (COG) D9803. The PMRMS patients on IRS-IV with any high-risk features (cranial nerve palsy [CNP], cranial base bony erosion [CBBE], or ICE) were treated immediately at day 0, and PMRMS patients without any of these 3 features received week 6-9 radiation therapy. The D9803 PMRMS patients with ICE received day 0 X-Ray Therapy (XRT) as well; however, those with either CNP or CBBE had XRT at week 12. Results: Compared with the 198 PMRMS patients from IRS-IV, the 192 PMRMS patients from D9803 had no difference (P<.05) in 5-year local failure (19% vs 19%), failure-free-survival (70% vs 67%), or overall survival (75% vs 73%) in aggregate. The 5-year local failure rates by subset did not differ when patients were classified as having no risk features (None, 15% vs 19%, P=.25), cranial nerve palsy/cranial base of skull erosion (CNP/CBBE, 15% vs 28%, P=.22), or intracranial extension (ICE, 21% vs 15%, P=.27). The D9083 patients were more likely to have received initial staging by magnetic resonance imaging (71% vs 53%). Conclusions: These data support that a delay in radiation therapy for high-risk PMRMS features of CNP/CBBE does not compromise clinical outcomes.

  20. Time resolved spectroscopy and photometry of three little known bright cataclysmic variables: LS IV -08° 3, HQ Monocerotis and ST Chamaeleontis

    NASA Astrophysics Data System (ADS)

    Bruch, Albert; Diaz, Marcos P.

    2017-01-01

    As part of a project to better characterize comparatively bright but so far little studied cataclysmic variables in the southern hemisphere, we have obtained spectroscopic and photometric data of the nova-like variables LS IV -08° 3 and HQ Mon, and of the Z Cam type dwarf nova ST Cha. The spectra of all systems are as expected for their respective types. We derive improved orbital ephemeris of LS IV -08° 3 and map its accretion disk in the light of the Hα emission using Doppler tomography. We find that the emission has a two component origin, arising in the outer parts of the accretion disk and possibly on the illuminated face of the secondary star. The light curve of LS IV -08° 3 exhibits a low level of flickering and indications for a modulation on the orbital period. Spectroscopy of HQ Mon suggests an orbital period of ≈ 5h.15 which is incompatible with previous (uncertain) estimates. The light curves show the typical low scale flickering of UX UMa type nova-like systems, superposed upon variations on longer time scales. During one night a modulation with a period of ≈ 41m is observed, visible for at least 4 hours. However, it does not repeat itself in other nights. A spectroscopic orbital period of ≈ 5h.5 is derived for ST Cha. A previously suspected period of 6h.8 (or alternatively 9h.6), based on historical photographic photometry is incompatible with the spectroscopic period. Moreover, we show that our new as well as previous photometry does not contain evidence for the quoted photometric period.

  1. Resolution of Large Azygos Vein Aneurysm Following Stent-Graft Shunt Placement in a Patient with Ehlers-Danlos Syndrome Type IV

    SciTech Connect

    D'Souza, Estelle S.; Williams, David M.; Deeb, G.M.; Cwikiel, Wojciech

    2006-10-15

    Ehlers-Danlos syndrome (EDS) type IV is a rare connective tissue disorder associated with thin-walled, friable arteries and veins predisposing patients to aneurysm formation, dissection, fistula formation, and vessel rupture. Azygos vein aneurysm is an extremely rare condition which has not been reported in association with EDS in the literature. We present a patient with EDS type IV and interrupted inferior vena cava (IVC) with azygos continuation who developed an azygos vein aneurysm. In order to decrease flow through the azygos vein and reduce the risk of aneurysm rupture, a stent-graft shunt was created from the right hepatic vein to the azygos vein via a transhepatic, retroperitoneal route. At 6 month follow-up the shunt was open and the azygos vein aneurysm had resolved.

  2. Interplanetary Type IV Bursts

    NASA Astrophysics Data System (ADS)

    Hillaris, A.; Bouratzis, C.; Nindos, A.

    2016-08-01

    We study the characteristics of moving type IV radio bursts that extend to hectometric wavelengths (interplanetary type IV or type {IV}_{{IP}} bursts) and their relationship with energetic phenomena on the Sun. Our dataset comprises 48 interplanetary type IV bursts observed with the Radio and Plasma Wave Investigation (WAVES) instrument onboard Wind in the 13.825 MHz - 20 kHz frequency range. The dynamic spectra of the Radio Solar Telescope Network (RSTN), the Nançay Decametric Array (DAM), the Appareil de Routine pour le Traitement et l' Enregistrement Magnetique de l' Information Spectral (ARTEMIS-IV), the Culgoora, Hiraso, and the Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation (IZMIRAN) Radio Spectrographs were used to track the evolution of the events in the low corona. These were supplemented with soft X-ray (SXR) flux-measurements from the Geostationary Operational Environmental Satellite (GOES) and coronal mass ejections (CME) data from the Large Angle and Spectroscopic Coronagraph (LASCO) onboard the Solar and Heliospheric Observatory (SOHO). Positional information of the coronal bursts was obtained by the Nançay Radioheliograph (NRH). We examined the relationship of the type IV events with coronal radio bursts, CMEs, and SXR flares. The majority of the events (45) were characterized as compact, their duration was on average 106 minutes. This type of events was, mostly, associated with M- and X-class flares (40 out of 45) and fast CMEs, 32 of these events had CMEs faster than 1000 km s^{-1}. Furthermore, in 43 compact events the CME was possibly subjected to reduced aerodynamic drag as it was propagating in the wake of a previous CME. A minority (three) of long-lived type {IV}_{{IP}} bursts was detected, with durations from 960 minutes to 115 hours. These events are referred to as extended or long duration and appear to replenish their energetic electron content, possibly from electrons escaping from the corresponding coronal

  3. TRANSIT TIMING OBSERVATIONS FROM KEPLER. IV. CONFIRMATION OF FOUR MULTIPLE-PLANET SYSTEMS BY SIMPLE PHYSICAL MODELS

    SciTech Connect

    Fabrycky, Daniel C.; Ford, Eric B.; Moorhead, Althea V.; Steffen, Jason H.; Rowe, Jason F.; Christiansen, Jessie L.; Carter, Joshua A.; Fressin, Francois; Geary, John; Batalha, Natalie M.; Borucki, William J.; Bryson, Steve; Haas, Michael R.; Buchhave, Lars A.; Ciardi, David R.; Fanelli, Michael N.; Hall, Jennifer R. [Orbital Sciences Corporation and others

    2012-05-10

    Eighty planetary systems of two or more planets are known to orbit stars other than the Sun. For most, the data can be sufficiently explained by non-interacting Keplerian orbits, so the dynamical interactions of these systems have not been observed. Here we present four sets of light curves from the Kepler spacecraft, each which of shows multiple planets transiting the same star. Departure of the timing of these transits from strict periodicity indicates that the planets are perturbing each other: the observed timing variations match the forcing frequency of the other planet. This confirms that these objects are in the same system. Next we limit their masses to the planetary regime by requiring the system remain stable for astronomical timescales. Finally, we report dynamical fits to the transit times, yielding possible values for the planets' masses and eccentricities. As the timespan of timing data increases, dynamical fits may allow detailed constraints on the systems' architectures, even in cases for which high-precision Doppler follow-up is impractical.

  4. Characterization of type I, II, III, IV, and V collagens by time-resolved laser-induced fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Marcu, Laura; Cohen, David; Maarek, Jean-Michel I.; Grundfest, Warren S.

    2000-04-01

    The relative proportions of genetically distinct collagen types in connective tissues vary with tissue type and change during disease progression, development, wound healing, aging. This study aims to 1) characterize the spectro- temporal fluorescence emission of fiber different types of collagen and 2) assess the ability of time-resolved laser- induced fluorescence spectroscopy to distinguish between collagen types. Fluorescence emission of commercially available purified samples was induced with nitrogen laser excitation pulses and detected with a MCP-PMT connected to a digital storage oscilloscope. The recorded time-resolved emission spectra displayed distinct fluorescence emission characteristics for each collagen type. The time domain information complemented the spectral domain intensity data for improved discrimination between different collagen types. Our results reveal that analysis of the fluorescence emission can be used to characterize different species of collagen. Also, the results suggest that time-resolved spectroscopy can be used for monitoring of connective tissue matrix composition changes due to various pathological and non-pathological conditions.

  5. AN EXPERIMENT IN BASIC AIRBORNE ELECTRONICS TRAINING, PART IV-- EFFECT OF REDUCTION IN TRAINING TIME ON FLEET PERFORMANCE. FINAL REPORT.

    ERIC Educational Resources Information Center

    BALDWIN, ROBERT O.; AND OTHERS

    THREE PRECEDING REPORTS PRESENTED THE EFFECTS OF SHORTENING TRAINING TIME IN AVIONICS FUNDAMENTALS AND AVIATION ELECTRONICS TECHNICIAN (RADAR) TRAINING UPON THE FINAL COMPREHENSIVE EXAMINATION IN THESE COURSES AND UPON PERFORMANCE IN A SUBSEQUENT EQUIPMENT COURSE. THIS REPORT COMPARES THE ON THE JOB PERFORMANCE OF GRADUATES FROM FOUR GROUPS…

  6. The investigation of timing large area scintillation detectors with SiPM light sensors properties

    NASA Astrophysics Data System (ADS)

    Runtso, M. F.; Naumov, P. Yu; Naumov, P. P.; Maklyaev, E. F.; Kaplin, V. A.; Fomin, V. S.; Razzhivin, I. S.; Melikyan, Yu A.

    2017-01-01

    The timing large area plastic scintillation detectors with silicon photomultipliers as photosensors properties were investigated using a cosmic radiation at the ground level. Different techniques of the amplitude spectra and efficiency measurements were implemented. The measurements results are presented.

  7. Berkeley Supernova Ia Program - IV. Carbon detection in early-time optical spectra of Type Ia supernovae

    NASA Astrophysics Data System (ADS)

    Silverman, Jeffrey M.; Filippenko, Alexei V.

    2012-09-01

    While O is often seen in spectra of Type Ia supernovae (SNe Ia) as both unburned fuel and a product of C burning, C is only occasionally seen at the earliest times and represents the most direct way of investigating primordial white dwarf material and its relation to SN Ia explosion scenarios and mechanisms. In this paper, we search for C absorption features in 188 optical spectra of 144 low-redshift (z < 0.1) SNe Ia with ages ≲3.6 d after maximum brightness. These data were obtained as part of the Berkeley Supernova Ia Program (BSNIP) and represent the largest set of SNe Ia in which C has ever been searched. We find that ˜11 per cent of the SNe studied show definite C absorption features, while ˜25 per cent show some evidence for C II in their spectra. Also, if one obtains a spectrum at ≲ -5 d, then there is a better than 30 per cent chance of detecting a distinct absorption feature from C II. SNe Ia that show C are found to resemble those without C in many respects, but objects with C tend to have bluer optical colours than those without C. The typical expansion velocity of the C II λ6580 feature is measured to be 12 000-13 000 km s-1, and the ratio of the C II λ6580 to Si II λ6355 velocities is remarkably constant with time and among different objects with a median value of ˜1.05. While the pseudo-equivalent widths (pEWs) of the C II λλ6580 and 7234 features are found mostly to decrease with time, we see evidence of a significant increase in pEW between ˜12 and 11 d before maximum brightness, which is actually predicted by some theoretical models. The range of pEWs measured from the BSNIP data implies a range of C masses in SN Ia ejecta of about (2-30) × 10-3 M⊙.

  8. Coalescence computations for large samples drawn from populations of time-varying sizes

    PubMed Central

    Polanski, Andrzej; Szczesna, Agnieszka; Garbulowski, Mateusz; Kimmel, Marek

    2017-01-01

    We present new results concerning probability distributions of times in the coalescence tree and expected allele frequencies for coalescent with large sample size. The obtained results are based on computational methodologies, which involve combining coalescence time scale changes with techniques of integral transformations and using analytical formulae for infinite products. We show applications of the proposed methodologies for computing probability distributions of times in the coalescence tree and their limits, for evaluation of accuracy of approximate expressions for times in the coalescence tree and expected allele frequencies, and for analysis of large human mitochondrial DNA dataset. PMID:28170404

  9. Coalescence computations for large samples drawn from populations of time-varying sizes.

    PubMed

    Polanski, Andrzej; Szczesna, Agnieszka; Garbulowski, Mateusz; Kimmel, Marek

    2017-01-01

    We present new results concerning probability distributions of times in the coalescence tree and expected allele frequencies for coalescent with large sample size. The obtained results are based on computational methodologies, which involve combining coalescence time scale changes with techniques of integral transformations and using analytical formulae for infinite products. We show applications of the proposed methodologies for computing probability distributions of times in the coalescence tree and their limits, for evaluation of accuracy of approximate expressions for times in the coalescence tree and expected allele frequencies, and for analysis of large human mitochondrial DNA dataset.

  10. Spitzer Survey of the Large Magellanic Cloud, Surveying the Agents of a Galaxy's Evolution (sage). IV. Dust Properties in the Interstellar Medium

    NASA Astrophysics Data System (ADS)

    Bernard, Jean-Philippe; Reach, William T.; Paradis, Deborah; Meixner, Margaret; Paladini, Roberta; Kawamura, Akiko; Onishi, Toshikazu; Vijh, Uma; Gordon, Karl; Indebetouw, Remy; Hora, Joseph L.; Whitney, Barbara; Blum, Robert; Meade, Marilyn; Babler, Brian; Churchwell, Ed B.; Engelbracht, Charles W.; For, Bi-Qing; Misselt, Karl; Leitherer, Claus; Cohen, Martin; Boulanger, François; Frogel, Jay A.; Fukui, Yasuo; Gallagher, Jay; Gorjian, Varoujan; Harris, Jason; Kelly, Douglas; Latter, William B.; Madden, Suzanne; Markwick-Kemper, Ciska; Mizuno, Akira; Mizuno, Norikazu; Mould, Jeremy; Nota, Antonella; Oey, M. S.; Olsen, Knut; Panagia, Nino; Perez-Gonzalez, Pablo; Shibai, Hiroshi; Sato, Shuji; Smith, Linda; Staveley-Smith, Lister; Tielens, A. G. G. M.; Ueta, Toshiya; Van Dyk, Schuyler; Volk, Kevin; Werner, Michael; Zaritsky, Dennis

    2008-09-01

    mass increase of sime13% of the total dust mass in selected regions. The most likely explanation is that the 70 μm excess is due to the production of large very small grains (VSG) through erosion of larger grains in the diffuse medium. This FIR excess could be due to intrinsic variations of the dust/gas ratio, which would then vary from 4.6 to 2.3 times lower than the MW values across the LMC, but X CO values derived from the IR emission would then be about three times lower than those derived from the Virial analysis of the CO data. We also investigate the possibility that the FIR excess is associated with an additional gas component undetected in the available gas tracers. Assuming a constant dust abundance in all ISM phases, the additional gas component would have twice the known H I mass. We show that it is plausible that the FIR excess is due to cold atomic gas that is optically thick in the 21 cm line, while the contribution by a pure H2 phase with no CO emission remains a possible explanation.

  11. Binaural detection with narrowband and wideband reproducible noise maskers. IV. Models using interaural time, level, and envelope differences.

    PubMed

    Mao, Junwen; Carney, Laurel H

    2014-02-01

    The addition of out-of-phase tones to in-phase noises results in dynamic interaural level difference (ILD) and interaural time difference (ITD) cues for the dichotic tone-in-noise detection task. Several models have been used to predict listeners' detection performance based on ILD, ITD, or different combinations of the two cues. The models can be tested using detection performance from an ensemble of reproducible-noise maskers. Previous models cannot predict listeners' detection performance for reproducible-noise maskers without fitting the data. Here, two models were tested for narrowband and wideband reproducible-noise experiments. One model was a linear combination of ILD and ITD that included the generally ignored correlation between the two cues. The other model was based on a newly proposed cue, the slope of the interaural envelope difference (SIED). Predictions from both models explained a significant portion of listeners' performance for detection of a 500-Hz tone in wideband noise. Predictions based on the SIED approached the predictable variance in the wideband condition. The SIED represented a nonlinear combination of ILD and ITD, with the latter cue dominating. Listeners did not use a common strategy (cue) to detect tones in the narrowband condition and may use different single frequencies or different combinations of frequency channels.

  12. Axially symmetric two-body problem in general relativity. IV. Boundary conditions, time scales, and the quadrupole formula

    SciTech Connect

    Cooperstock, F.I.

    1982-06-15

    The analysis of the field equations and the conservation laws is extended into the skin boundary region which maintains the initially static configuration of the two fluid spheres. Although this leads to a correction of the gravitational-radiation energy-loss rate from a dependence of Eapprox...cap alpha../sup -4/rho/sub 0/ /sup -4/ to ..cap alpha../sup -6/rho/sub 0/ /sup -2/, the importance of the nonlinear structure-dependent terms remain and the essential conclusion, that the quadrupole formula does not apply to this problem, is unaltered. The hydrodynamic, stress-breaking, and free-fall time scales are considered. It is shown that insofar as the quadrupole-formula comparison for free-fall is concerned, only the contribution from bulk motion of the fluid spheres need be considered since tidal quadrupole deformation contributes negligibly to the quadrupole formula. With reference to our problem, it is shown that a recent derivation of the quadrupole formula for free-fall is incorrect and it is suggested that certain other derivations may be applicable only to the radiation damping of a single body.

  13. Evaluation of luminescence decay measurements probed on pure and doped Pt(IV) hexahalogeno complexes I. Exponential rise time and decay curves applying various statistical tests

    NASA Astrophysics Data System (ADS)

    Biertümpel, Ingo; Schmidtke, Hans-Herbert

    1997-02-01

    Statistical methods are shown to be superior for evaluating luminescence lifetime curves of complex compounds to usual regression procedures. A simple model for the intensity change with time valid for the rise time and the decay period of emission is proposed which considers contributions of exponential decay in time intervals which compare to the time resolution of the equipment available. Mean square fittings to measured points furnish lifetimes and amplitudes of multi-exponential model functions (hypotheses) which are tested applying various statistical methods. Well-established procedures as residual analysis, the autocorrelation function, chi-square test, Durbin-Watson and the Run test are used for investigating whether the results are normal distributed and autocorrelated. For physical interpretation a hypothesis function is only acceptable if all test statistics support non-rejection. Curve fitting and statistical checks are applied on low-temperature lifetime measurements carried out on various Pt(IV) hexahalogeno complexes. Pure materials and compounds doped in suitable host crystals supply essentially identical decay parameters.

  14. Time-saving screening for diabetes in patients with coronary artery disease: a report from EUROASPIRE IV

    PubMed Central

    Gyberg, Viveca; De Bacquer, Dirk; Kotseva, Kornelia; De Backer, Guy; Schnell, Oliver; Tuomilehto, Jaakko; Wood, David; Rydén, Lars

    2016-01-01

    Background WHO advocates 2-hour oral glucose tolerance test (OGTT) for detecting diabetes mellitus (DM). OGTT is the most sensitive method to detect DM in patients with coronary artery disease (CAD). Considered time consuming, the use of OGTT is unsatisfactory. A 1-hour plasma glucose (1hPG) test has not been evaluated as an alternative in patients with CAD. Objectives To create an algorithm based on glycated haemoglobin (HbA1c), fasting plasma glucose (FPG) and 1hPG limiting the need of a 2-hour plasma glucose (2hPG) in patients with CAD. Methods 951 patients with CAD without DM underwent OGTT. A 2hPG≥11.1 mmol/L was the reference for undiagnosed DM. The yield of HbA1c, FPG and 1hPG was compared with that of 2hPG. Results Mean FPG was 6.2±0.9 mmol/L, and mean HbA1c 5.8±0.4%. Based on 2hPG≥11.1 mmol/L 122 patients (13%) had DM. There was no value for the combination of HbA1c and FPG to rule out or in DM (HbA1c≥6.5%; FPG≥7.0 mmol/L). In receiver operating characteristic analysis a 1hPG≥12 mmol/L balanced sensitivity and specificity for detecting DM (both=82%; positive and negative predictive values 40% and 97%). A combination of FPG<6.5 mmol/L and 1hPG<11 mmol/L excluded 99% of DM. A combination of FPG>8.0 mmol/L and 1hPG>15 mmol/L identified 100% of patients with DM. Conclusions Based on its satisfactory accuracy to detect DM an algorithm is proposed for screening for DM in patients with CAD decreasing the need for a 2-hour OGTT by 71%. PMID:27932342

  15. Improved time response for large area microchannel plate photomultiplier tubes in fusion diagnostics

    SciTech Connect

    Milnes, J. S. Conneely, T. M.; Howorth, J.; Horsfield, C. J.

    2014-11-15

    Fusion diagnostics that utilise high speed scintillators often need to capture a large area of light with a high degree of time accuracy. Microchannel plate (MCP) photomultiplier tubes (PMTs) are recognised as the leading device for capturing fast optical signals. However, when manufactured in their traditional proximity focused construction, the time response performance is reduced as the active area increases. This is due to two main factors: the capacitance of a large anode and the difficulty of obtaining small pore MCPs with a large area. Collaboration between Photek and AWE has produced prototype devices that combine the excellent time response of small area MCP-PMTs with a large active area by replacing the traditional proximity-gap front section with an electro-optically focused photocathode to MCP. We present results from both single and double MCP devices with a 40 mm diameter active area and show simulations for the 100 mm device being built this year.

  16. Improved time response for large area microchannel plate photomultiplier tubes in fusion diagnostics.

    PubMed

    Milnes, J S; Horsfield, C J; Conneely, T M; Howorth, J

    2014-11-01

    Fusion diagnostics that utilise high speed scintillators often need to capture a large area of light with a high degree of time accuracy. Microchannel plate (MCP) photomultiplier tubes (PMTs) are recognised as the leading device for capturing fast optical signals. However, when manufactured in their traditional proximity focused construction, the time response performance is reduced as the active area increases. This is due to two main factors: the capacitance of a large anode and the difficulty of obtaining small pore MCPs with a large area. Collaboration between Photek and AWE has produced prototype devices that combine the excellent time response of small area MCP-PMTs with a large active area by replacing the traditional proximity-gap front section with an electro-optically focused photocathode to MCP. We present results from both single and double MCP devices with a 40 mm diameter active area and show simulations for the 100 mm device being built this year.

  17. Non-Linear Dynamics and Stability of Circular Cylindrical Shells Containing Flowing Fluid. Part Iv: Large-Amplitude Vibrations with Flow

    NASA Astrophysics Data System (ADS)

    AMABILI, M.; PELLICANO, F.; PAÏDOUSSIS, M. P.

    2000-11-01

    The response of a shell conveying fluid to harmonic excitation, in the spectral neighbourhood of one of the lowest natural frequencies, is investigated for different flow velocities. The theoretical model has already been presented in Part I of the present study. Non-linearities due to moderately large-amplitude shell motion are considered by using Donnell's non-linear shallow-shell theory. Linear potential flow theory is applied to describe the fluid-structure interaction by using the model proposed by Paı̈doussis and Denise. For different amplitudes and frequencies of the excitation and for different flow velocities, the following are investigated numerically: (1) periodic response of the system; (2) unsteady and stochastic motion; (3) loss of stability by jumps to bifurcated branches. The effect of the flow velocity on the non-linear periodic response of the system has also been investigated. Poincaré maps and bifurcation diagrams are used to study the unsteady and stochastic dynamics of the system. Amplitude modulated motions, multi-periodic solutions, chaotic responses, cascades of bifurcations as the route to chaos and the so-called “blue sky catastrophe” phenomenon have all been observed for different values of the system parameters; the latter two have been predicted here probably for the first time for the dynamics of circular cylindrical shells.

  18. Uranium(IV) hydrolysis constants and solubility product of UO sub 2 times xH sub 2 O(am)

    SciTech Connect

    Rai, D.; Felmy, A.R.; Ryan, J.L. )

    1990-01-24

    The solubility of UO{sub 2} {times} xH{sub 2}O was examined in dilute solutions at room temperature in the pH range from 2 to 12. Iron powder and Eu{sup 2+} were used to effectively eliminate O{sub 2} and to maintain the possibility of oxidation of U(IV) to U(VI) during the experiments. The UO{sub 2} {times} xH{sub 2}O was found to be amorphous to x-rays, and its solubility, especially at pH values > 4, was found to be 3-4 orders of magnitude lower than previously reported. Values of log K at zero ionic strength for the solubility reaction UO{sub 2} {times} xH{sub 2}O(am) + 3H{sup +} {r equilibrium} UOH{sup 3+} + (x+1)H{sub 2}, and recalculation of values of the first hydrolysis constant from spectrophotometric data reported in the literature were consistent with both the reliable solubility and spectrophotometric data and the thermodynamic properties of other actinides. 23 refs., 4 figs., 2 tabs.

  19. Exploration of PBPK Model-Calculation of Drug Time Course in Tissue Using IV Bolus Drug Plasma Concentration-Time Profile and the Physiological Parameters of the Organ.

    PubMed

    Berezhkovskiy, Leonid M

    2016-08-01

    An uncommon innovative consideration of the well-stirred linear physiologically based pharmacokinetic model and the drug plasma concentration-time profile, which is measured in routine intravenous bolus pharmacokinetic study, was applied for the calculation of the drug time course in human tissues. This cannot be obtained in the in vivo pharmacokinetic study. The physiological parameters of the organ such as organ tissue volume, organ blood flow rate, and its vascular volume were used in the calculation. The considered method was applied to calculate the time course of midazolam, alprazolam, quinidine, and diclofenac in human organs or tissues. The suggested method might be applied for the prediction of drug concentration-time profile in tissues and consequently the drug concentration level in the targeted tissue, as well as the possible undesirable toxic levels in other tissues. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  20. The VLT/NaCo large program to probe the occurrence of exoplanets and brown dwarfs at wide orbits. IV. Gravitational instability rarely forms wide, giant planets

    NASA Astrophysics Data System (ADS)

    Vigan, A.; Bonavita, M.; Biller, B.; Forgan, D.; Rice, K.; Chauvin, G.; Desidera, S.; Meunier, J.-C.; Delorme, P.; Schlieder, J. E.; Bonnefoy, M.; Carson, J.; Covino, E.; Hagelberg, J.; Henning, T.; Janson, M.; Lagrange, A.-M.; Quanz, S. P.; Zurlo, A.; Beuzit, J.-L.; Boccaletti, A.; Buenzli, E.; Feldt, M.; Girard, J. H. V.; Gratton, R.; Kasper, M.; Le Coroller, H.; Mesa, D.; Messina, S.; Meyer, M.; Montagnier, G.; Mordasini, C.; Mouillet, D.; Moutou, C.; Reggiani, M.; Segransan, D.; Thalmann, C.

    2017-06-01

    Understanding the formation and evolution of giant planets (≥1 MJup) at wide orbital separation (≥5 AU) is one of the goals of direct imaging. Over the past 15 yr, many surveys have placed strong constraints on the occurrence rate of wide-orbit giants, mostly based on non-detections, but very few have tried to make a direct link with planet formation theories. In the present work, we combine the results of our previously published VLT/NaCo large program with the results of 12 past imaging surveys to constitute a statistical sample of 199 FGK stars within 100 pc, including three stars with sub-stellar companions. Using Monte Carlo simulations and assuming linear flat distributions for the mass and semi-major axis of planets, we estimate the sub-stellar companion frequency to be within 0.75-5.70% at the 68% confidence level (CL) within 20-300 AU and 0.5-75 MJup, which is compatible with previously published results. We also compare our results with the predictions of state-of-the-art population synthesis models based on the gravitational instability (GI) formation scenario with and without scattering. We estimate that in both the scattered and non-scattered populations, we would be able to detect more than 30% of companions in the 1-75 MJup range (95% CL). With the threesub-stellar detections in our sample, we estimate the fraction of stars that host a planetary system formed by GI to be within 1.0-8.6% (95% CL). We also conclude that even though GI is not common, it predicts a mass distribution of wide-orbit massive companions that is much closer to what is observed than what the core accretion scenario predicts. Finally, we associate the present paper with the release of the Direct Imaging Virtual Archive (DIVA), a public database that aims at gathering the results of past, present, and future direct imaging surveys. Based on observations collected at the European Southern Observatory, Chile (ESO Large Program 184.C-0157 and Open Time 089.C-0137A and 090.C-0252

  1. High resolution time-of-flight measurements in small and large scintillation counters

    NASA Astrophysics Data System (ADS)

    D'Agostini, G.; Marini, G.; Martellotti, G.; Massa, F.; Rambaldi, A.; Sciubba, A.

    1981-06-01

    In a test run, the experimental time-of-flight resolution was measured for several different scintillation counters of small (10 × 5 cm 2) and large (100 × 15 cm 2 and 75 × 25 cm 2) area. The design characteristics were decided on the basis of theoretical Monte Carlo calculations. We report results using twisted, fish-tail, and rectangular light-guides and different types of scintillator (NE114 and PILOT U). Time resolution up to ˜130-150 ps fwhm for the small counters and up to ˜280-300 ps fwhm for the large counters were obtained. The spatial resolution from time measurements in the large counters is also reported. The results of Monte Carlo calculations on the type of scintillator, the shape and dimensions of the light-guides, and the nature of the external wrapping surfaces — to be used in order to optimize the time resolution — are also summarized.

  2. Joint association of screen time and physical activity on self-rated health and life satisfaction in children and adolescents: the CASPIAN-IV study.

    PubMed

    Matin, Nassim; Kelishadi, Roya; Heshmat, Ramin; Motamed-Gorji, Nazgol; Djalalinia, Shirin; Motlagh, Mohammad Esmaeil; Ardalan, Gelayol; Arefirad, Tahereh; Mohammadi, Rasool; Safiri, Saeid; Qorbani, Mostafa

    2017-01-01

    Self-rated health and life satisfaction are two subjective measures for assessing overall health status. This study aims to investigate the association of self-rated health and life satisfaction with physical activity and screen time. As part of the fourth survey of a national surveillance program in Iran (CASPIAN-IV study), 14 880 students aged 6 to 18 years were selected via multi-stage cluster sampling from 30 provinces. Data were obtained from the WHO Global School-Based Student Health Survey questionnaire. A total of 13 486 students with mean age of 12.47 (SD 3.36) completed the study. In crude model both prolonged screen time and physical activity were associated with favorable life satisfaction and self-rated health. However, in multivariate analysis only high physical activity was associated with good self-rated health (OR 1.37) and life satisfaction (OR 1.39), while prolonged screen time was not associated with good self-rated health (OR 1.02) and life satisfaction (OR 0.94). For combined screen time-physical activity variable, low screen time-high physical activity combination had the highest OR for both good self-rated health (OR 1.37) and life satisfaction (OR 1.43) in multivariate analysis. Our findings suggest that increasing physical activity is more crucial than emphasizing reducing screen time in improving the well-being of children and adolescents. © The Author 2016. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Stochastic, resonance-free multiple time-step algorithm for molecular dynamics with very large time steps

    NASA Astrophysics Data System (ADS)

    Leimkuhler, Ben; Margul, Daniel T.; Tuckerman, Mark E.

    2013-12-01

    Molecular dynamics is one of the most commonly used approaches for studying the dynamics and statistical distributions of physical, chemical, and biological systems using atomistic or coarse-grained models. It is often the case, however, that the interparticle forces drive motion on many time scales, and the efficiency of a calculation is limited by the choice of time step, which must be sufficiently small that the fastest force components are accurately integrated. Multiple time-stepping algorithms partially alleviate this inefficiency by assigning to each time scale an appropriately chosen step-size. As the fast forces are often computationally cheaper to evaluate than the slow forces, this results in a significant gain in efficiency. However, such approaches are limited by resonance phenomena, wherein motion on the fastest time scales limits the step sizes associated with slower time scales. In atomistic models of biomolecular systems, for example, resonances limit the largest time step to around 5-6 fs. Stochastic processes promote mixing and ergodicity in dynamical systems and reduce the impact of resonant modes. In this paper, we introduce a set of stochastic isokinetic equations of motion that are shown to be rigorously ergodic, largely free of resonances, and can be integrated using a multiple time-stepping algorithm which is easily implemented in existing molecular dynamics codes. The technique is applied to a simple, illustrative problem and then to a more realistic system, namely, a flexible water model. Using this approach outer time steps as large as 100 fs are shown to be possible.

  4. Once-daily indacaterol 75 μg in moderate- to-severe COPD: results of a Phase IV study assessing time until patients' perceived onset of effect.

    PubMed

    Siler, Thomas M; LaForce, Craig F; Kianifard, Farid; Williams, James; Spangenthal, Selwyn

    2014-01-01

    Indacaterol 75 μg once daily is a long-acting β2 agonist approved for maintenance bronchodilator treatment in patients with chronic obstructive pulmonary disease (COPD). The purpose of this study was to evaluate patients' perception of onset of effect with a single dose. In this double-blind, crossover, Phase IV study, 40 patients were randomized to receive a single dose of indacaterol 75 μg or placebo via a dry powder inhaler device. The primary variable was time until patient's perception of onset of effect, using a simple self-administered (nonvalidated) questionnaire that patients answered at nine protocol-specified time points. Exploratory variables included change in forced expiratory volume in 1 second (FEV1) and change in percent predicted FEV1 from predose to postdose (determined 60-75 minutes postdose). The least-squares mean time to patient's perception of onset of effect was 25.4 minutes and 23.9 minutes for indacaterol and placebo, respectively. There was no significant effect for treatment, period, or sequence on the time to patient's perception. In addition, no statistically significant differences between treatments were observed for patient's global satisfaction with onset of effect and global expectation of treatment adherence. For the exploratory variable change in FEV1 from predose to postdose, indacaterol showed superiority over placebo with a clinically relevant least-squares mean treatment difference of 0.12 L (P<0.0001). There was little or no association between patient's perception of time to onset of effect and change in FEV1, or change in percent predicted FEV1. Both treatments were well tolerated. A single dose of indacaterol 75 μg did not separate from placebo in terms of patient perception of onset, although there was an improvement in FEV1 for indacaterol compared with placebo. Development and use of a validated questionnaire may be needed to address the inconsistency in evaluating this patient-related outcome.

  5. Versatile synchronized real-time MEG hardware controller for large-scale fast data acquisition

    NASA Astrophysics Data System (ADS)

    Sun, Limin; Han, Menglai; Pratt, Kevin; Paulson, Douglas; Dinh, Christoph; Esch, Lorenz; Okada, Yoshio; Hämäläinen, Matti

    2017-05-01

    Versatile controllers for accurate, fast, and real-time synchronized acquisition of large-scale data are useful in many areas of science, engineering, and technology. Here, we describe the development of a controller software based on a technique called queued state machine for controlling the data acquisition (DAQ) hardware, continuously acquiring a large amount of data synchronized across a large number of channels (>400) at a fast rate (up to 20 kHz/channel) in real time, and interfacing with applications for real-time data analysis and display of electrophysiological data. This DAQ controller was developed specifically for a 384-channel pediatric whole-head magnetoencephalography (MEG) system, but its architecture is useful for wide applications. This controller running in a LabVIEW environment interfaces with microprocessors in the MEG sensor electronics to control their real-time operation. It also interfaces with a real-time MEG analysis software via transmission control protocol/internet protocol, to control the synchronous acquisition and transfer of the data in real time from >400 channels to acquisition and analysis workstations. The successful implementation of this controller for an MEG system with a large number of channels demonstrates the feasibility of employing the present architecture in several other applications.

  6. Versatile synchronized real-time MEG hardware controller for large-scale fast data acquisition.

    PubMed

    Sun, Limin; Han, Menglai; Pratt, Kevin; Paulson, Douglas; Dinh, Christoph; Esch, Lorenz; Okada, Yoshio; Hämäläinen, Matti

    2017-05-01

    Versatile controllers for accurate, fast, and real-time synchronized acquisition of large-scale data are useful in many areas of science, engineering, and technology. Here, we describe the development of a controller software based on a technique called queued state machine for controlling the data acquisition (DAQ) hardware, continuously acquiring a large amount of data synchronized across a large number of channels (>400) at a fast rate (up to 20 kHz/channel) in real time, and interfacing with applications for real-time data analysis and display of electrophysiological data. This DAQ controller was developed specifically for a 384-channel pediatric whole-head magnetoencephalography (MEG) system, but its architecture is useful for wide applications. This controller running in a LabVIEW environment interfaces with microprocessors in the MEG sensor electronics to control their real-time operation. It also interfaces with a real-time MEG analysis software via transmission control protocol/internet protocol, to control the synchronous acquisition and transfer of the data in real time from >400 channels to acquisition and analysis workstations. The successful implementation of this controller for an MEG system with a large number of channels demonstrates the feasibility of employing the present architecture in several other applications.

  7. Research of time discrimination circuits for PMT signal readout over large dynamic range in LHAASO WCDA

    NASA Astrophysics Data System (ADS)

    Ma, C.; Zhao, L.; Dong, R.; Jiang, Z.; Chu, S.; Gao, X.; Liu, S.; An, Q.

    2016-11-01

    In the readout electronics of the Water Cerenkov Detector Array (WCDA) in the Large High Altitude Air Shower Observatory (LHAASO), both high-resolution charge and time measurement are required over a dynamic range from 1 photoelectron (P.E.) to 4000 P.E. for the PMT signal readout. In this paper, we present our work on the design of time discrimination circuits in LHAASO WCDA, especially on improvement to reduce the circuit dead time. Several approaches were studied through analysis and simulations, and actual circuits were designed and tested in the laboratory to evaluate the performance. Test results indicate that a time resolution better than 500 ps RMS is achieved in the whole large dynamic range, and the circuit dead time is successfully reduced to less than 200 ns.

  8. Large lateral photovoltaic effect with ultrafast relaxation time in SnSe/Si junction

    NASA Astrophysics Data System (ADS)

    Wang, Xianjie; Zhao, Xiaofeng; Hu, Chang; Zhang, Yang; Song, Bingqian; Zhang, Lingli; Liu, Weilong; Lv, Zhe; Zhang, Yu; Tang, Jinke; Sui, Yu; Song, Bo

    2016-07-01

    In this paper, we report a large lateral photovoltaic effect (LPE) with ultrafast relaxation time in SnSe/p-Si junctions. The LPE shows a linear dependence on the position of the laser spot, and the position sensitivity is as high as 250 mV mm-1. The optical response time and the relaxation time of the LPE are about 100 ns and 2 μs, respectively. The current-voltage curve on the surface of the SnSe film indicates the formation of an inversion layer at the SnSe/p-Si interface. Our results clearly suggest that most of the excited-electrons diffuse laterally in the inversion layer at the SnSe/p-Si interface, which results in a large LPE with ultrafast relaxation time. The high positional sensitivity and ultrafast relaxation time of the LPE make the SnSe/p-Si junction a promising candidate for a wide range of optoelectronic applications.

  9. Effects of Eddy Viscosity on Time Correlations in Large Eddy Simulation

    NASA Technical Reports Server (NTRS)

    He, Guowei; Rubinstein, R.; Wang, Lian-Ping; Bushnell, Dennis M. (Technical Monitor)

    2001-01-01

    Subgrid-scale (SGS) models for large. eddy simulation (LES) have generally been evaluated by their ability to predict single-time statistics of turbulent flows such as kinetic energy and Reynolds stresses. Recent application- of large eddy simulation to the evaluation of sound sources in turbulent flows, a problem in which time, correlations determine the frequency distribution of acoustic radiation, suggest that subgrid models should also be evaluated by their ability to predict time correlations in turbulent flows. This paper compares the two-point, two-time Eulerian velocity correlation evaluated from direct numerical simulation (DNS) with that evaluated from LES, using a spectral eddy viscosity, for isotropic homogeneous turbulence. It is found that the LES fields are too coherent, in the sense that their time correlations decay more slowly than the corresponding time. correlations in the DNS fields. This observation is confirmed by theoretical estimates of time correlations using the Taylor expansion technique. Tile reason for the slower decay is that the eddy viscosity does not include the random backscatter, which decorrelates fluid motion at large scales. An effective eddy viscosity associated with time correlations is formulated, to which the eddy viscosity associated with energy transfer is a leading order approximation.

  10. Mining precise cause and effect rules in large time series data of socio-economic indicators.

    PubMed

    Hira, Swati; Deshpande, P S

    2016-01-01

    Discovery of cause-effect relationships, particularly in large databases of time-series is challenging because of continuous data of different characteristics and complex lagged relationships. In this paper, we have proposed a novel approach, to extract cause-effect relationships in large time series data set of socioeconomic indicators. The method enhances the scope of relationship discovery to cause-effect relationships by identifying multiple causal structures such as binary, transitive, many to one and cyclic. We use temporal association and temporal odds ratio to exclude noncausal association and to ensure the high reliability of discovered causal rules. We assess the method with both synthetic and real-world datasets. Our proposed method will help to build quantitative models to analyze socioeconomic processes by generating a precise cause-effect relationship between different economic indicators. The outcome shows that the proposed method can effectively discover existing causality structure in large time series databases.

  11. Large-alphabet time-frequency entangled quantum key distribution by means of time-to-frequency conversion

    NASA Astrophysics Data System (ADS)

    Nunn, J.; Wright, L. J.; Söller, C.; Zhang, L.; Walmsley, I. A.; Smith, B. J.

    2013-07-01

    We introduce a novel time-frequency quantum key distribution (TFQKD) scheme based on photon pairs entangled in these two conjugate degrees of freedom. The scheme uses spectral detection and phase modulation to enable measurements in the temporal basis by means of time-to-frequency conversion. This allows large-alphabet encoding to be implemented with realistic components. A general security analysis for TFQKD with binned measurements reveals a close connection with finite-dimensional QKD protocols and enables analysis of the effects of dark counts on the secure key size.

  12. ECLIPSE TIMINGS OF THE TRANSIENT LOW-MASS X-RAY BINARY EXO 0748-676. IV. THE ROSSI X-RAY TIMING EXPLORER ECLIPSES

    SciTech Connect

    Wolff, Michael T.; Ray, Paul S.; Wood, Kent S.; Hertz, Paul L. E-mail: Paul.Ray@nrl.navy.mil E-mail: Paul.Hertz@nasa.gov

    2009-07-01

    We report our complete database of X-ray eclipse timings of the low-mass X-ray binary EXO 0748-676 observed by the Rossi X-Ray Timing Explorer (RXTE) satellite. As of this writing we have accumulated 443 full X-ray eclipses, 392 of which have been observed with the Proportional Counter Array on RXTE. These include both observations where an eclipse was specifically targeted and those eclipses found in the RXTE data archive. Eclipse cycle count has been maintained since the discovery of the EXO 0748-676 system in 1985 February. We describe our observing and analysis techniques for each eclipse and describe improvements we have made since the last compilation by Wolff et al. The principal result of this paper is the database containing the timing results from a seven-parameter fit to the X-ray light curve for each observed eclipse along with the associated errors in the fitted parameters. Based on the standard O - C analysis, EXO 0748-676 has undergone four distinct orbital period epochs since its discovery. In addition, EXO 0748-676 shows small-scale events in the O - C curve that are likely due to short-lived changes in the secondary star.

  13. A robust and high-performance queue management controller for large round trip time networks

    NASA Astrophysics Data System (ADS)

    Khoshnevisan, Ladan; Salmasi, Farzad R.

    2016-05-01

    Congestion management for transmission control protocol is of utmost importance to prevent packet loss within a network. This necessitates strategies for active queue management. The most applied active queue management strategies have their inherent disadvantages which lead to suboptimal performance and even instability in the case of large round trip time and/or external disturbance. This paper presents an internal model control robust queue management scheme with two degrees of freedom in order to restrict the undesired effects of large and small round trip time and parameter variations in the queue management. Conventional approaches such as proportional integral and random early detection procedures lead to unstable behaviour due to large delay. Moreover, internal model control-Smith scheme suffers from large oscillations due to the large round trip time. On the other hand, other schemes such as internal model control-proportional integral and derivative show excessive sluggish performance for small round trip time values. To overcome these shortcomings, we introduce a system entailing two individual controllers for queue management and disturbance rejection, simultaneously. Simulation results based on Matlab/Simulink and also Network Simulator 2 (NS2) demonstrate the effectiveness of the procedure and verify the analytical approach.

  14. Sorption properties of Th(IV) on the raw diatomite--effects of contact time, pH, ionic strength and temperature.

    PubMed

    Sheng, Guodong; Hu, Jun; Wang, Xiangke

    2008-10-01

    Diatomite has a number of unique physicochemical properties and has diversified industrial uses. Natural diatomite has been tested as a potential sorbent for the removal of Th(IV) from aqueous solutions. The results indicate that sorption of Th(IV) is strongly dependent on ionic strength at pH<3, and is independent of ionic strength at pH>3. Outer-sphere complexation or ion exchange may be the main sorption mechanism of Th(IV) to diatomite at low pH values, whereas the sorption of Th(IV) at pH>3 is mainly dominated by inner-sphere complexation or precipitation. The competition for Th(IV) between aqueous or surface adsorbed anions (e.g., herein ClO(4)(-), NO(3)(-) and Cl(-)) and surface functional groups of diatomite is important for Th(IV) sorption. The thermodynamic data (DeltaH(0), DeltaS(0), DeltaG(0)) are calculated from the temperature-dependent sorption isotherms. The results suggest that sorption process of Th(IV) on diatomite is spontaneous and endothermic.

  15. CAN LARGE TIME DELAYS OBSERVED IN LIGHT CURVES OF CORONAL LOOPS BE EXPLAINED IN IMPULSIVE HEATING?

    SciTech Connect

    Lionello, Roberto; Linker, Jon A.; Mikić, Zoran; Alexander, Caroline E.; Winebarger, Amy R. E-mail: linkerj@predsci.com E-mail: caroline.e.alexander@nasa.gov

    2016-02-20

    The light curves of solar coronal loops often peak first in channels associated with higher temperatures and then in those associated with lower temperatures. The delay times between the different narrowband EUV channels have been measured for many individual loops and recently for every pixel of an active region observation. The time delays between channels for an active region exhibit a wide range of values. The maximum time delay in each channel pair can be quite large, i.e., >5000 s. These large time delays make-up 3%–26% (depending on the channel pair) of the pixels where a trustworthy, positive time delay is measured. It has been suggested that these time delays can be explained by simple impulsive heating, i.e., a short burst of energy that heats the plasma to a high temperature, after which the plasma is allowed to cool through radiation and conduction back to its original state. In this paper, we investigate whether the largest observed time delays can be explained by this hypothesis by simulating a series of coronal loops with different heating rates, loop lengths, abundances, and geometries to determine the range of expected time delays between a set of four EUV channels. We find that impulsive heating cannot address the largest time delays observed in two of the channel pairs and that the majority of the large time delays can only be explained by long, expanding loops with photospheric abundances. Additional observations may rule out these simulations as an explanation for the long time delays. We suggest that either the time delays found in this manner may not be representative of real loop evolution, or that the impulsive heating and cooling scenario may be too simple to explain the observations, and other potential heating scenarios must be explored.

  16. Development of Design Technology on Thermal-Hydraulic Performance in Tight-Lattice Rod Bundle: IV Large Paralleled Simulation by the Advanced Two-fluid Model Code

    NASA Astrophysics Data System (ADS)

    Misawa, Takeharu; Yoshida, Hiroyuki; Akimoto, Hajime

    In Japan Atomic Energy Agency (JAEA), the Innovative Water Reactor for Flexible Fuel Cycle (FLWR) has been developed. For thermal design of FLWR, it is necessary to develop analytical method to predict boiling transition of FLWR. Japan Atomic Energy Agency (JAEA) has been developing three-dimensional two-fluid model analysis code ACE-3D, which adopts boundary fitted coordinate system to simulate complex shape channel flow. In this paper, as a part of development of ACE-3D to apply to rod bundle analysis, introduction of parallelization to ACE-3D and assessments of ACE-3D are shown. In analysis of large-scale domain such as a rod bundle, even two-fluid model requires large number of computational cost, which exceeds upper limit of memory amount of 1 CPU. Therefore, parallelization was introduced to ACE-3D to divide data amount for analysis of large-scale domain among large number of CPUs, and it is confirmed that analysis of large-scale domain such as a rod bundle can be performed by parallel computation with keeping parallel computation performance even using large number of CPUs. ACE-3D adopts two-phase flow models, some of which are dependent upon channel geometry. Therefore, analyses in the domains, which simulate individual subchannel and 37 rod bundle, are performed, and compared with experiments. It is confirmed that the results obtained by both analyses using ACE-3D show agreement with past experimental result qualitatively.

  17. Large-scale study of the interactions between proteins involved in type IV pilus biology in Neisseria meningitidis: characterization of a subcomplex involved in pilus assembly.

    PubMed

    Georgiadou, Michaella; Castagnini, Marta; Karimova, Gouzel; Ladant, Daniel; Pelicic, Vladimir

    2012-06-01

    The functionally versatile type IV pili (Tfp) are one of the most widespread virulence factors in bacteria. However, despite generating much research interest for decades, the molecular mechanisms underpinning the various aspects of Tfp biology remain poorly understood, mainly because of the complexity of the system. In the human pathogen Neisseria meningitidis for example, 23 proteins are dedicated to Tfp biology, 15 of which are essential for pilus biogenesis. One of the important gaps in our knowledge concerns the topology of this multiprotein machinery. Here we have used a bacterial two-hybrid system to identify and quantify the interactions between 11 Pil proteins from N. meningitidis. We identified 20 different binary interactions, many of which are novel. This represents the most complex interaction network between Pil proteins reported to date and indicates, among other things, that PilE, PilM, PilN and PilO, which are involved in pilus assembly, indeed interact. We focused our efforts on this subset of proteins and used a battery of assays to determine the membrane topology of PilN and PilO, map the interaction domains between PilE, PilM, PilN and PilO, and show that a widely conserved N-terminal motif in PilN is essential for both PilM-PilN interactions and pilus assembly. Finally, we show that PilP (another protein involved in pilus assembly) forms a complex with PilM, PilN and PilO. Taken together, these findings have numerous implications for understanding Tfp biology and provide a useful blueprint for future studies.

  18. Asthma, obesity, and eating behaviors according to the diagnostic and statistical manual of mental disorders IV in a large population-based sample of adolescents.

    PubMed

    Moreau, David; Kalaboka, Sofia; Choquet, Marie; Annesi-Maesano, Isabella

    2009-05-01

    Obesity is related to asthma, but factors influencing this relation have not been clearly defined. This study was designed to assess the role of eating behaviors and weight concerns in the association between obesity and asthma. A population-based sample of 11,710 adolescents, recruited from 186 secondary schools of 8 educational districts in France, completed a self-administered standardized questionnaire including DSM IV (Diagnostic and Statistical Manual of Mental Disorders) questions on eating disorders. Obesity (body mass index >/=95th percentile according to age and sex) was associated with asthma in girls (odds ratio: 1.48; 95% CI: 1.05, 2.08) but not in boys (odds ratio: 1.07; 95% CI: 0.75, 1.54). Both obese and asthmatic adolescents were more likely to have abnormal eating behaviors and weight concerns (P < 0.05). In an adjusted polytomous logistic model with 4 categories based on the presence and/or the absence of asthma and obesity as the dependent variable, the odds ratio for weight concerns increased from a minimum value for asthmatic nonobese adolescents (odds ratio: <1.5; P < 0.03) to a maximum value for asthmatic obese adolescents (odds ratio: >6.3; P < 0.001) with nonasthmatic, nonobese adolescents as the reference group. Similar patterns were observed for overweight. Our data suggest that, besides well-known factors such as genetic background, direct mechanical effects, and reduced physical activity, abnormal eating behaviors and weight concerns might intervene in the relation between obesity and asthma. Psychosocial dimension has to be considered to disentangle the complex relation between obesity and asthma in adolescence in view of prevention.

  19. Forced cubic Schrödinger equation with Robin boundary data: large-time asymptotics.

    PubMed

    Kaikina, Elena I

    2013-11-08

    We consider the initial-boundary-value problem for the cubic nonlinear Schrödinger equation, formulated on a half-line with inhomogeneous Robin boundary data. We study traditionally important problems of the theory of nonlinear partial differential equations, such as the global-in-time existence of solutions to the initial-boundary-value problem and the asymptotic behaviour of solutions for large time.

  20. Forced cubic Schrödinger equation with Robin boundary data: large-time asymptotics

    PubMed Central

    Kaikina, Elena I.

    2013-01-01

    We consider the initial-boundary-value problem for the cubic nonlinear Schrödinger equation, formulated on a half-line with inhomogeneous Robin boundary data. We study traditionally important problems of the theory of nonlinear partial differential equations, such as the global-in-time existence of solutions to the initial-boundary-value problem and the asymptotic behaviour of solutions for large time. PMID:24204185

  1. Ultra-violet light-emitting diode calibration system for timing large area scintillation detectors

    NASA Astrophysics Data System (ADS)

    Naumov, P. Yu; Runtso, M. F.; Naumov, P. P.; Maklyaev, E. F.; Kaplin, V. A.; Fomin, V. S.; Razzhivin, I. S.; Melikyan, Yu A.

    2017-01-01

    Timing large area plastic scintillation detectors are developing for the space gamma-ray telescopes now. For the in-flight calibration of these detectors the use of ultra-violet light-emitting diode, irradiating the 1 m long detector module at the center of its lateral side is suggested. The results of the measurements show the possibility of this calibration system implementation as for amplitude as for timing properties monitoring.

  2. Dynamical model and nonextensive statistical mechanics of a market index on large time windows

    NASA Astrophysics Data System (ADS)

    Ausloos, M.; Ivanova, K.

    2003-10-01

    The shape and tails of partial distribution functions (PDF) for a financial signal, i.e., the S&P500 and the turbulent nature of the markets are linked through a model encompassing Tsallis nonextensive statistics and leading to evolution equations of the Langevin and Fokker-Planck type. A model originally proposed to describe the intermittent behavior of turbulent flows describes the behavior of normalized log returns for such a financial market index, for small and large time windows, and both for small and large log returns. These turbulent market volatility (of normalized log returns) distributions can be sufficiently well fitted with a χ2 distribution. The transition between the small time scale model of nonextensive, intermittent process, and the large scale Gaussian extensive homogeneous fluctuation picture is found to be at ca. a 200 day time lag. The intermittency exponent κ in the framework of the Kolmogorov log-normal model is found to be related to the scaling exponent of the PDF moments, thereby giving weight to the model. The large value of κ points to a large number of cascades in the turbulent process. The first Kramers-Moyal coefficient in the Fokker-Planck equation is almost equal to zero, indicating “no restoring force.” A comparison is made between normalized log returns and mere price increments.

  3. The Space-Time Conservative Schemes for Large-Scale, Time-Accurate Flow Simulations with Tetrahedral Meshes

    NASA Technical Reports Server (NTRS)

    Venkatachari, Balaji Shankar; Streett, Craig L.; Chang, Chau-Lyan; Friedlander, David J.; Wang, Xiao-Yen; Chang, Sin-Chung

    2016-01-01

    Despite decades of development of unstructured mesh methods, high-fidelity time-accurate simulations are still predominantly carried out on structured, or unstructured hexahedral meshes by using high-order finite-difference, weighted essentially non-oscillatory (WENO), or hybrid schemes formed by their combinations. In this work, the space-time conservation element solution element (CESE) method is used to simulate several flow problems including supersonic jet/shock interaction and its impact on launch vehicle acoustics, and direct numerical simulations of turbulent flows using tetrahedral meshes. This paper provides a status report for the continuing development of the space-time conservation element solution element (CESE) numerical and software framework under the Revolutionary Computational Aerosciences (RCA) project. Solution accuracy and large-scale parallel performance of the numerical framework is assessed with the goal of providing a viable paradigm for future high-fidelity flow physics simulations.

  4. Calculation of neutron die-away times in a large-vehicle portal monitor

    SciTech Connect

    Lillie, R.A.; Santoro, R.T.; Alsmiller, R.G. Jr.

    1980-05-01

    Monte Carlo methods have been used to calculate neutron die-away times in a large-vehicle portal monitor. These calculations were performed to investigate the adequacy of using neutron die-away time measurements to detect the clandestine movement of shielded nuclear materials. The geometry consisted of a large tunnel lined with He/sup 3/ proportional counters. The time behavior of the (n,p) capture reaction in these counters was calculated when the tunnel contained a number of different tractor-trailer load configurations. Neutron die-away times obtained from weighted least squares fits to these data were compared. The change in neutron die-away time due to the replacement of cargo in a fully loaded truck with a spherical shell containing 240 kg of borated polyethylene was calculated to be less than 3%. This result together with the overall behavior of neutron die-away time versus mass inside the tunnel strongly suggested that measurements of this type will not provide a reliable means of detecting shielded nuclear materials in a large vehicle. 5 figures, 4 tables.

  5. Free-decay time-domain modal identification for large space structures

    NASA Technical Reports Server (NTRS)

    Kim, Hyoung M.; Vanhorn, David A.; Doiron, Harold H.

    1992-01-01

    Concept definition studies for the Modal Identification Experiment (MIE), a proposed space flight experiment for the Space Station Freedom (SSF), have demonstrated advantages and compatibility of free-decay time-domain modal identification techniques with the on-orbit operational constraints of large space structures. Since practical experience with modal identification using actual free-decay responses of large space structures is very limited, several numerical and test data reduction studies were conducted. Major issues and solutions were addressed, including closely-spaced modes, wide frequency range of interest, data acquisition errors, sampling delay, excitation limitations, nonlinearities, and unknown disturbances during free-decay data acquisition. The data processing strategies developed in these studies were applied to numerical simulations of the MIE, test data from a deployable truss, and launch vehicle flight data. Results of these studies indicate free-decay time-domain modal identification methods can provide accurate modal parameters necessary to characterize the structural dynamics of large space structures.

  6. Managing the Editing Function on Large Publication Tasks with Short Flow Times.

    ERIC Educational Resources Information Center

    Santa, Terry M. Dalla

    Large publication tasks with short flow times require that several editors be assigned to work together as part of a larger publication team that includes management, engineer-writers, publishing logistics personnel, word processor operators, illustrators, and printers. Team-edited publications have special problems, and the technical editing and…

  7. Efficiency and large deviations in time-asymmetric stochastic heat engines

    NASA Astrophysics Data System (ADS)

    Gingrich, Todd R.; Rotskoff, Grant M.; Vaikuntanathan, Suriyanarayanan; Geissler, Phillip L.

    2014-10-01

    In a stochastic heat engine driven by a cyclic non-equilibrium protocol, fluctuations in work and heat give rise to a fluctuating efficiency. Using computer simulations and tools from large deviation theory, we have examined these fluctuations in detail for a model two-state engine. We find in general that the form of efficiency probability distributions is similar to those described by Verley et al (2014 Nat. Commun. 5 4721), in particular featuring a local minimum in the long-time limit. In contrast to the time-symmetric engine protocols studied previously, however, this minimum need not occur at the value characteristic of a reversible Carnot engine. Furthermore, while the local minimum may reside at the global minimum of a large deviation rate function, it does not generally correspond to the least likely efficiency measured over finite time. We introduce a general approximation for the finite-time efficiency distribution, P(η ), based on large deviation statistics of work and heat, that remains very accurate even when P(η ) deviates significantly from its large deviation form.

  8. Water Quality Response Times to Pasture Management Changes in Small and Large Watersheds

    USDA-ARS?s Scientific Manuscript database

    To interpret the effects of best management practices on water quality at a regional or large watershed scale likely response times at various scales must be known. Therefore, 4 small (<1 ha, 2.5 ac) watersheds, in rotational grazing studies at the North Appalachian Experimental Watershed (NAEW) nea...

  9. Efficiency and large deviations in time-asymmetric stochastic heat engines

    DOE PAGES

    Gingrich, Todd R.; Rotskoff, Grant M.; Vaikuntanathan, Suriyanarayanan; ...

    2014-10-24

    In a stochastic heat engine driven by a cyclic non-equilibrium protocol, fluctuations in work and heat give rise to a fluctuating efficiency. Using computer simulations and tools from large deviation theory, we have examined these fluctuations in detail for a model two-state engine. We find in general that the form of efficiency probability distributions is similar to those described by Verley et al (2014 Nat. Commun. 5 4721), in particular featuring a local minimum in the long-time limit. In contrast to the time-symmetric engine protocols studied previously, however, this minimum need not occur at the value characteristic of a reversible Carnot engine. Furthermore, while the local minimum may reside at the global minimum of a large deviation rate function, it does not generally correspond to the least likely efficiency measured over finite time. Lastly, we introduce a general approximation for the finite-time efficiency distribution,more » $$P(\\eta )$$, based on large deviation statistics of work and heat, that remains very accurate even when $$P(\\eta )$$ deviates significantly from its large deviation form.« less

  10. Managing the Editing Function on Large Publication Tasks with Short Flow Times.

    ERIC Educational Resources Information Center

    Santa, Terry M. Dalla

    Large publication tasks with short flow times require that several editors be assigned to work together as part of a larger publication team that includes management, engineer-writers, publishing logistics personnel, word processor operators, illustrators, and printers. Team-edited publications have special problems, and the technical editing and…

  11. Numerical Estimation of the Lyapunov Exponents of Chaotic Time Series Corrupted by Noises of Large Amplitude

    NASA Astrophysics Data System (ADS)

    Mera, M. Eugenia; Morán, Manuel

    2009-09-01

    We show that the Lyapunov spectrum of chaotic vector time series corrupted by noises with a noise-to-signal ratio of up to 100% in one of the coordinates can be estimated using the output of a noise reduction algorithm designed to deal with noises of large amplitude.

  12. An Efficient Format for Nearly Constant-Time Access to Arbitrary Time Intervals in Large Trace Files

    DOE PAGES

    Chan, Anthony; Gropp, William; Lusk, Ewing

    2008-01-01

    A powerful method to aid in understanding the performance of parallel applications uses log or trace files containing time-stamped events and states (pairs of events). These trace files can be very large, often hundreds or even thousands of megabytes. Because of the cost of accessing and displaying such files, other methods are often used that reduce the size of the tracefiles at the cost of sacrificing detail or other information. This paper describes a hierarchical trace file format that provides for display of an arbitrary time window in a time independent of the total size of the file andmore » roughly proportional to the number of events within the time window. This format eliminates the need to sacrifice data to achieve a smaller trace file size (since storage is inexpensive, it is necessary only to make efficient use of bandwidth to that storage). The format can be used to organize a trace file or to create a separate file of annotations that may be used with conventional trace files. We present an analysis of the time to access all of the events relevant to an interval of time and we describe experiments demonstrating the performance of this file format.« less

  13. RankExplorer: Visualization of Ranking Changes in Large Time Series Data.

    PubMed

    Shi, Conglei; Cui, Weiwei; Liu, Shixia; Xu, Panpan; Chen, Wei; Qu, Huamin

    2012-12-01

    For many applications involving time series data, people are often interested in the changes of item values over time as well as their ranking changes. For example, people search many words via search engines like Google and Bing every day. Analysts are interested in both the absolute searching number for each word as well as their relative rankings. Both sets of statistics may change over time. For very large time series data with thousands of items, how to visually present ranking changes is an interesting challenge. In this paper, we propose RankExplorer, a novel visualization method based on ThemeRiver to reveal the ranking changes. Our method consists of four major components: 1) a segmentation method which partitions a large set of time series curves into a manageable number of ranking categories; 2) an extended ThemeRiver view with embedded color bars and changing glyphs to show the evolution of aggregation values related to each ranking category over time as well as the content changes in each ranking category; 3) a trend curve to show the degree of ranking changes over time; 4) rich user interactions to support interactive exploration of ranking changes. We have applied our method to some real time series data and the case studies demonstrate that our method can reveal the underlying patterns related to ranking changes which might otherwise be obscured in traditional visualizations.

  14. Large Time Out-of-Equilibrium Dynamics of a Manifold in a Random Potential

    NASA Astrophysics Data System (ADS)

    Cugliandolo, Leticia F.; Kurchan, Jorge; Le Doussal, Pierre

    1996-03-01

    We study the out-of-equilibrium dynamics of an elastic manifold in a random potential using mean-field theory. We find two asymptotic time regimes: (i) stationary dynamics; (ii) slow aging dynamics with violation of equilibrium theorems. We obtain an analytical solution valid for all large times with universal scalings of two-time quantities with space. A nonanalytic scaling function crosses over to ultrametricity when the correlations become long range. We propose procedures to test numerically or experimentally the extent to which this scenario holds for a given system.

  15. Large-scale structure effects on the gravitational lens image positions and time delay

    NASA Technical Reports Server (NTRS)

    Seljak, Uros

    1994-01-01

    We compute the fluctuations in gravitational lens image positions and time delay caused by large-scale structure correlations. We show that these fluctuations can be expressed as a simple integral over the density power spectrum. Using the Cosmic Background Explorer (COBE) normalization we find that positions of objects at cosmological distances are expected to deviate from their true positions by few arcminutes. These deflections are not directly observable. The positions of the images relative to one another fluctuate by a few percent of the relative separation, implying that one does not expect multiple images to be produced by large-scale structure. Nevertheless, the fluctuations are larger than the observational errors on the positions and affect reconstructions of the lens potential. The time delay fluctuations have a geometrical and a gravitational contribution. Both are much larger than the expected time delay from the primary lens, but partially cancel each other. We find that large-scale structure weakly affects the time delay and time delay measurements can be used as a probe of the distance scale in the universe.

  16. Improvement of time resolution in large area single gap Resistive Plate Chambers

    NASA Astrophysics Data System (ADS)

    Bhatt, A. D.; Majumder, G.; Mondal, N. K.; Pathaleswar; Satyanarayana, B.

    2017-02-01

    The intrinsic gain of a single gap Resistive Plate Chamber (RPC) is affected by several factors, e.g., variation in the thicknesses of glass electrode, button and side spacer, different composition of gas due to improper flow, leaks in the detector volume, etc. The position dependent gain is one of the dominant components of the time resolution of a large area single gap RPC. Besides, strip multiplicity as well as lateral position of the trajectory of the charged particle in RPC strip also result in variation of timing information. The observation of large signals produced by the charged particles passing close to the button spacers also has some repercussion on the overall timing resolution of an RPC. A new offline correction technique to achieve time resolution below 1 ns is reported in this paper. This technique is validated using an RPC cosmic ray telescope (1 × 1m2) at TIFR. We also suggest a few alternative solutions to improve the time resolution during the operational phase of the INO-ICAL experiment. The techniques presented here are useful not only for ICAL, but also for any detector deploying RPCs in large scale.

  17. Efficiency and Large Deviations in Time-Asymmetric Stochastic Heat Engines

    NASA Astrophysics Data System (ADS)

    Gingrich, Todd; Rotskoff, Grant; Vaikuntanathan, Suriyanarayanan; Geissler, Phillip

    2015-03-01

    In a stochastic heat engine driven by a cyclic non-equilibrium protocol, fluctuations in work and heat give rise to a fluctuating efficiency. Using computer simulations and tools from large deviation theory, we have examined these fluctuations in detail for a model two-state engine. We find in general that the form of efficiency probability distributions is similar to those described by Verley et al. [2014 Nat Comm, 5 4721], in particular featuring a local minimum in the long-time limit. In contrast to the time-symmetric engine protocols studied previously, however, this minimum need not occur at the value characteristic of a reversible Carnot engine. Furthermore, while the local minimum may reside at the global minimum of a large deviation rate function, it does not generally correspond to the least likely efficiency measured over finite time.

  18. Memory effects in the statistics of interoccurrence times between large returns in financial records

    NASA Astrophysics Data System (ADS)

    Bogachev, Mikhail I.; Bunde, Armin

    2008-09-01

    We study the statistics of the interoccurrence times between events above some threshold Q in two kinds of multifractal data sets (multiplicative random cascades and multifractal random walks) with vanishing linear correlations. We show that in both data sets the relevant quantities (probability density functions and the autocorrelation function of the interoccurrence times, as well as the conditional return period) are governed by power laws with exponents that depend explicitly on the considered threshold. By studying a large number of representative financial records (market indices, stock prices, exchange rates, and commodities), we show explicitly that the interoccurrence times between large daily returns follow the same behavior, in a nearly quantitative manner. We conclude that this kind of behavior is a general consequence of the nonlinear memory inherent in the multifractal data sets.

  19. Spectra of large time-lagged correlation matrices from random matrix theory

    NASA Astrophysics Data System (ADS)

    Nowak, Maciej A.; Tarnowski, Wojciech

    2017-06-01

    We analyze the spectral properties of large, time-lagged correlation matrices using the tools of random matrix theory. We compare predictions of the one-dimensional spectra, based on approaches already proposed in the literature. Employing the methods of free random variables and diagrammatic techniques, we solve a general random matrix problem, namely the spectrum of a matrix \\frac{1}{T}XA{{X}\\dagger} , where X is an N× T Gaussian random matrix and A is any T× T , not necessarily symmetric (Hermitian) matrix. Using this result, we study the spectral features of the large lagged correlation matrices as a function of the depth of the time-lag. We also analyze the properties of left and right eigenvector correlations for the time-lagged matrices. We positively verify our results by the numerical simulations.

  20. Memory effects in the statistics of interoccurrence times between large returns in financial records.

    PubMed

    Bogachev, Mikhail I; Bunde, Armin

    2008-09-01

    We study the statistics of the interoccurrence times between events above some threshold Q in two kinds of multifractal data sets (multiplicative random cascades and multifractal random walks) with vanishing linear correlations. We show that in both data sets the relevant quantities (probability density functions and the autocorrelation function of the interoccurrence times, as well as the conditional return period) are governed by power laws with exponents that depend explicitly on the considered threshold. By studying a large number of representative financial records (market indices, stock prices, exchange rates, and commodities), we show explicitly that the interoccurrence times between large daily returns follow the same behavior, in a nearly quantitative manner. We conclude that this kind of behavior is a general consequence of the nonlinear memory inherent in the multifractal data sets.

  1. Passivity control with practically finite-time convergence for large space structures

    NASA Astrophysics Data System (ADS)

    Hu, Quan; Li, Jinyue; Zhang, Jingrui

    2017-02-01

    A nonlinear output feedback control law based on passivity is proposed to reduce the vibration of large space structures. The considered system is assumed to be equipped with collocated actuators and sensors. The concept of practically finite-time stability is first developed to describe the finite-time convergence of a passive system. Then, an output feedback is introduced to drive the trajectories of a passive system into a small set around the origin in finite time. Finally, the proposed control strategy is applied to the vibration suppression of large space structures with distributed thrusters and velocity sensors or torque outputting devices and angular rate sensors. Numerical simulations are conducted to validate the effectiveness of the proposed controller.

  2. Precursory measure of interoccurrence time associated with large earthquakes in the Burridge-Knopoff model

    SciTech Connect

    Hasumi, Tomohiro

    2008-11-13

    We studied the statistical properties of interoccurrence time i.e., time intervals between successive earthquakes in the two-dimensional (2D) Burridge-Knopoff (BK) model, and have found that these statistics can be classified into three types: the subcritical state, the critical state, and the supercritical state. The survivor function of interoccurrence time is well fitted by the Zipf-Mandelbrot type power law in the subcritical regime. However, the fitting accuracy of this distribution tends to be worse as the system changes from the subcritical state to the supercritical state. Because the critical phase of a fault system in nature changes from the subcritical state to the supercritical state prior to a forthcoming large earthquake, we suggest that the fitting accuracy of the survivor distribution can be another precursory measure associated with large earthquakes.

  3. The faster internal clock in ADHD is related to lower processing speed: WISC-IV profile analyses and time estimation tasks facilitate the distinction between real ADHD and pseudo-ADHD.

    PubMed

    Walg, Marco; Hapfelmeier, Gerhard; El-Wahsch, Daniel; Prior, Helmut

    2017-03-10

    Alterations in temporal processing may represent a primary cause of key symptoms in ADHD. This study is aimed at investigating the nature of time-processing alterations in ADHD and assessing the possible utility of testing time estimation for clinical diagnostics. Retrospective verbal time estimation in the range of several minutes was examined in 50 boys with ADHD and 53 boys with other mental disorders. All participants (age 7-16) attended an outpatient clinic for ADHD diagnostics. The diagnostic assessment included the WISC-IV. Subjects with ADHD made longer and less accurate duration estimates than the clinical control group. The ADHD group showed a specific WISC-IV profile with processing speed deficits. In the ADHD group there was a correlation between processing speed and quality of time estimation that was not observed in the comparison group: higher processing speed indices were related to more accurate duration estimates. The findings provide support for the presence of a faster internal clock in subjects with ADHD and lend further support to the existence of a specific WISC-IV profile in subjects with ADHD. The results show that analyzing WISC-IV profiles and time estimation tasks are useful differential diagnosis tools, particularly when it comes to distinguishing between "real ADHD" and pseudo-ADHD.

  4. Once-daily indacaterol 75 μg in moderate- to-severe COPD: results of a Phase IV study assessing time until patients’ perceived onset of effect

    PubMed Central

    Siler, Thomas M; LaForce, Craig F; Kianifard, Farid; Williams, James; Spangenthal, Selwyn

    2014-01-01

    Background Indacaterol 75 μg once daily is a long-acting β2 agonist approved for maintenance bronchodilator treatment in patients with chronic obstructive pulmonary disease (COPD). The purpose of this study was to evaluate patients’ perception of onset of effect with a single dose. Methods In this double-blind, crossover, Phase IV study, 40 patients were randomized to receive a single dose of indacaterol 75 μg or placebo via a dry powder inhaler device. The primary variable was time until patient’s perception of onset of effect, using a simple self-administered (nonvalidated) questionnaire that patients answered at nine protocol-specified time points. Exploratory variables included change in forced expiratory volume in 1 second (FEV1) and change in percent predicted FEV1 from predose to postdose (determined 60–75 minutes postdose). Results The least-squares mean time to patient’s perception of onset of effect was 25.4 minutes and 23.9 minutes for indacaterol and placebo, respectively. There was no significant effect for treatment, period, or sequence on the time to patient’s perception. In addition, no statistically significant differences between treatments were observed for patient’s global satisfaction with onset of effect and global expectation of treatment adherence. For the exploratory variable change in FEV1 from predose to postdose, indacaterol showed superiority over placebo with a clinically relevant least-squares mean treatment difference of 0.12 L (P<0.0001). There was little or no association between patient’s perception of time to onset of effect and change in FEV1, or change in percent predicted FEV1. Both treatments were well tolerated. Conclusion A single dose of indacaterol 75 μg did not separate from placebo in terms of patient perception of onset, although there was an improvement in FEV1 for indacaterol compared with placebo. Development and use of a validated questionnaire may be needed to address the inconsistency in

  5. TIME DISTRIBUTIONS OF LARGE AND SMALL SUNSPOT GROUPS OVER FOUR SOLAR CYCLES

    SciTech Connect

    Kilcik, A.; Yurchyshyn, V. B.; Abramenko, V.; Goode, P. R.; Cao, W.; Ozguc, A.; Rozelot, J. P.

    2011-04-10

    Here we analyze solar activity by focusing on time variations of the number of sunspot groups (SGs) as a function of their modified Zurich class. We analyzed data for solar cycles 20-23 by using Rome (cycles 20 and 21) and Learmonth Solar Observatory (cycles 22 and 23) SG numbers. All SGs recorded during these time intervals were separated into two groups. The first group includes small SGs (A, B, C, H, and J classes by Zurich classification), and the second group consists of large SGs (D, E, F, and G classes). We then calculated small and large SG numbers from their daily mean numbers as observed on the solar disk during a given month. We report that the time variations of small and large SG numbers are asymmetric except for solar cycle 22. In general, large SG numbers appear to reach their maximum in the middle of the solar cycle (phases 0.45-0.5), while the international sunspot numbers and the small SG numbers generally peak much earlier (solar cycle phases 0.29-0.35). Moreover, the 10.7 cm solar radio flux, the facular area, and the maximum coronal mass ejection speed show better agreement with the large SG numbers than they do with the small SG numbers. Our results suggest that the large SG numbers are more likely to shed light on solar activity and its geophysical implications. Our findings may also influence our understanding of long-term variations of the total solar irradiance, which is thought to be an important factor in the Sun-Earth climate relationship.

  6. The large discretization step method for time-dependent partial differential equations

    NASA Technical Reports Server (NTRS)

    Haras, Zigo; Taasan, Shlomo

    1995-01-01

    A new method for the acceleration of linear and nonlinear time dependent calculations is presented. It is based on the Large Discretization Step (LDS) approximation, defined in this work, which employs an extended system of low accuracy schemes to approximate a high accuracy discrete approximation to a time dependent differential operator. Error bounds on such approximations are derived. These approximations are efficiently implemented in the LDS methods for linear and nonlinear hyperbolic equations, presented here. In these algorithms the high and low accuracy schemes are interpreted as the same discretization of a time dependent operator on fine and coarse grids, respectively. Thus, a system of correction terms and corresponding equations are derived and solved on the coarse grid to yield the fine grid accuracy. These terms are initialized by visiting the fine grid once in many coarse grid time steps. The resulting methods are very general, simple to implement and may be used to accelerate many existing time marching schemes.

  7. Design verification of large time constant thermal shields for optical reference cavities.

    PubMed

    Zhang, J; Wu, W; Shi, X H; Zeng, X Y; Deng, K; Lu, Z H

    2016-02-01

    In order to achieve high frequency stability in ultra-stable lasers, the Fabry-Pérot reference cavities shall be put inside vacuum chambers with large thermal time constants to reduce the sensitivity to external temperature fluctuations. Currently, the determination of thermal time constants of vacuum chambers is based either on theoretical calculation or time-consuming experiments. The first method can only apply to simple system, while the second method will take a lot of time to try out different designs. To overcome these limitations, we present thermal time constant simulation using finite element analysis (FEA) based on complete vacuum chamber models and verify the results with measured time constants. We measure the thermal time constants using ultrastable laser systems and a frequency comb. The thermal expansion coefficients of optical reference cavities are precisely measured to reduce the measurement error of time constants. The simulation results and the experimental results agree very well. With this knowledge, we simulate several simplified design models using FEA to obtain larger vacuum thermal time constants at room temperature, taking into account vacuum pressure, shielding layers, and support structure. We adopt the Taguchi method for shielding layer optimization and demonstrate that layer material and layer number dominate the contributions to the thermal time constant, compared with layer thickness and layer spacing.

  8. Large aperture fast neutron imaging detector with 10-ns time resolution

    NASA Astrophysics Data System (ADS)

    Arikawa, Y.; Matsubara, S.; Abe, Y.; Kato, Y.; Kishimoto, H.; Yogo, A.; Nishimura, H.; Nakai, M.; Shiraga, H.; Fujioka, S.; Azechi, H.; Otake, Y.; Mima, K.; Honda, Y.

    2017-02-01

    Fast neutrons, which are neutrons with energies greater than 1 MeV, are expected to be a source of nondestructive inspection for a large-size infrastructure such as a bridge girder because of their mean free path exceeding the meter. A neutron-imaging device with 10-ns time resolution can discriminate pulsed neutrons from X-rays via time of flight. For this purpose, we require a fast-response neutron imager with large aperture and high image resolution. A neutron-imaging device with time resolution of 10 ns and aperture size of 40 cm × 60 cm was developed. It was filled with fast response liquid scintillator [1] in an aluminum honeycomb plate, which converts neutrons to optical light images. The scintillation light images were relayed using an optical lens and detected using a fast response image intensified CCD. The detector was tested at an electron linear accelerator (LINAC) facility in Osaka University. A short X-ray pulse (30 ps pulse duration) was generated using LINAC, and X-ray radiograph images were obtained with a 10- ns exposure time duration. The radiograph images were well attenuated within 10-ns from the X-ray injection. A high energy X-ray image and a neutron radiograph image of a 30-cm thick concrete block with iron blocks located behind it were successfully observed. This promising technique could facilitate nondestructive inspection of large concrete constructions.

  9. Falcon: Visual analysis of large, irregularly sampled, and multivariate time series data in additive manufacturing

    DOE PAGES

    Steed, Chad A.; Halsey, William; Dehoff, Ryan; ...

    2017-02-16

    Flexible visual analysis of long, high-resolution, and irregularly sampled time series data from multiple sensor streams is a challenge in several domains. In the field of additive manufacturing, this capability is critical for realizing the full potential of large-scale 3D printers. Here, we propose a visual analytics approach that helps additive manufacturing researchers acquire a deep understanding of patterns in log and imagery data collected by 3D printers. Our specific goals include discovering patterns related to defects and system performance issues, optimizing build configurations to avoid defects, and increasing production efficiency. We introduce Falcon, a new visual analytics system thatmore » allows users to interactively explore large, time-oriented data sets from multiple linked perspectives. Falcon provides overviews, detailed views, and unique segmented time series visualizations, all with adjustable scale options. To illustrate the effectiveness of Falcon at providing thorough and efficient knowledge discovery, we present a practical case study involving experts in additive manufacturing and data from a large-scale 3D printer. The techniques described are applicable to the analysis of any quantitative time series, though the focus of this paper is on additive manufacturing.« less

  10. Observation of quantum particles on a large space-time scale

    NASA Astrophysics Data System (ADS)

    Landau, L. J.

    1994-10-01

    A quantum particle observed on a sufficiently large space-time scale can be described by means of classical particle trajectories. The joint distribution for large-scale multiple-time position and momentum measurements on a nonrelativistic quantum particle moving freely in R v is given by straight-line trajectories with probabilities determined by the initial momentum-space wavefunction. For large-scale toroidal and rectangular regions the trajectories are geodesics. In a uniform gravitational field the trajectories are parabolas. A quantum counting process on free particles is also considered and shown to converge in the large-space-time limit to a classical counting process for particles with straight-line trajectories. If the quantum particle interacts weakly with its environment, the classical particle trajectories may undergo random jumps. In the random potential model considered here, the quantum particle evolves according to a reversible unitary one-parameter group describing elastic scattering off static randomly distributed impurities (a quantum Lorentz gas). In the large-space-time weak-coupling limit a classical stochastic process is obtained with probability one and describes a classical particle moving with constant speed in straight lines between random jumps in direction. The process depends only on the ensemble value of the covariance of the random field and not on the sample field. The probability density in phase space associated with the classical stochastic process satisfies the linear Boltzmann equation for the classical Lorentz gas, which, in the limit h→0, goes over to the linear Landau equation. Our study of the quantum Lorentz gas is based on a perturbative expansion and, as in other studies of this system, the series can be controlled only for small values of the rescaled time and for Gaussian random fields. The discussion of classical particle trajectories for nonrelativistic particles on a macroscopic spacetime scale applies also to

  11. Subsurface Supergranular Vertical Flows as Measured Using Large Distance Separations in Time-Distance Helioseismology

    NASA Technical Reports Server (NTRS)

    Duvall, Thomas L., Jr.; Hanasoge, S. M.

    2012-01-01

    As large-distance rays (say, 10 - 24deg) approach the solar surface approximately vertically, travel times measured from surface pairs for these large separations are mostly sensitive to vertical flows, at least for shallow flows within a few Mm of the solar surface. All previous analyses of supergranulation have used smaller separations and have been hampered by the difficulty of separating the horizontal and vertical flow components. We find that the large-separation travel times associated with supergranulation cannot be studied using the standard phase-speed filters of time-distance helioseismology. These filters, whose use is based upon a refractive model of the perturbations, reduce the resultant travel time signal by at least an order of magnitude at some distances. More effective filters are derived. Modeling suggests that the center-annulus travel-time difference [outward-going time minus inward-going time] in the separation range delta= 10 - 24deg is insensitive to the horizontally diverging flow from the centers of the supergranules and should lead to a constant signal from the vertical flow. Our measurement of this quantity, 5.1+/-0.1 seconds, is constant over the distance range. This magnitude of the signal cannot be caused by the level of upflow at cell centers seen at the photosphere of 10 ms(exp-1) extended in depth. It requires the vertical flow to increase with depth. A simple Gaussian model of the increase with depth implies a peak upward flow of 240 ms(exp-1) at a depth of 2.3 Mm and a peak horizontal flow of 700 ms(exp-1) at a depth of 1.6 Mm.

  12. Maintaining large time steps in explicit finite element simulations using shape matching.

    PubMed

    Fierz, Basil; Spillmann, Jonas; Aguinaga Hoyos, Iker; Harders, Matthias

    2012-05-01

    We present a novel hybrid method to allow large time steps in explicit integrations for the simulation of deformable objects. In explicit integration schemes, the time step is typically limited by the size and the shape of the discretization elements as well as by the material parameters. We propose a two-step strategy to enable large time steps for meshes with elements potentially destabilizing the integration. First, the necessary time step for a stable computation is identified per element using modal analysis. This allows determining which elements have to be handled specially given a desired simulation time step. The identified critical elements are treated by a geometric deformation model, while the remaining ones are simulated with a standard deformation model (in our case, a corotational linear Finite Element Method). In order to achieve a valid deformation behavior, we propose a strategy to determine appropriate parameters for the geometric model. Our hybrid method allows taking much larger time steps than using an explicit Finite Element Method alone. The total computational costs per second are significantly lowered. The proposed scheme is especially useful for simulations requiring interactive mesh updates, such as for instance cutting in surgical simulations.

  13. Large-Strain Time-Temperature Equivalence and Adiabatic Heating of Polyethylene

    SciTech Connect

    Furmanski, Jevan; Brown, Eric; Cady, Carl M.

    2012-06-06

    Time-temperature equivalence is a well-known phenomenon in time-dependent material response, where rapid events at a moderate temperature are indistinguishable from some occurring at modest rates but elevated temperatures. However, there is as-yet little elucidation of how well this equivalence holds for substantial plastic strains. In this work, we demonstrate time-temperature equivalence over a large range in a previously studied high-density polyethylene formulation (HDPE). At strain-rates exceeding 0.1/s, adiabatic heating confounds the comparison of nominally isothermal material response, apparently violating time-temperature equivalence. Strain-rate jumps can be employed to access the instantaneous true strain rate without heating. Adiabatic heating effects were isolated by comparing a locus of isothermal instantaneous flow stress measurements from strain-rate jumps up to 1/s with the predicted equivalent states at 0.01/s and 0.001/s in compression. Excellent agreement between the isothermal jump condition locus and the quasi-static tests was observed up to 50% strain, yielding one effective isothermal plastic response for each material for a given time-temperature equivalent state. These results imply that time-temperature equivalence can be effectively used to predict the deformation response of polymers during extreme mechanical events (large strain and high strain-rate) from measurements taken at reduced temperatures and nominal strain-rates in the laboratory.

  14. Asymptotic behavior of solutions of the Korteweg-de Vries equation for large times

    SciTech Connect

    Buslaev, V.S.; Sukhanov, V.V.

    1986-09-10

    For the KdV equation a complete asymptotic expansion of the dispersive tail for large times is described, and generalized wave operators are introduced. The asymptotics for large times of the spectral Schroedinger equation with a potential of the type of a solution of the KdV equation is studied. It is shown that the KdV equation is connected in a specific manner with the structure of the asymptotics of solutions of the spectral equation. As a corollary, known explicit formulas for the leading terms of the asymptotics of solutions of the KdV equation in terms of spectral data corresponding to the initial conditions are obtained. A plan for justifying the results listed is outlined.

  15. Large-scale machine learning and evaluation platform for real-time traffic surveillance

    NASA Astrophysics Data System (ADS)

    Eichel, Justin A.; Mishra, Akshaya; Miller, Nicholas; Jankovic, Nicholas; Thomas, Mohan A.; Abbott, Tyler; Swanson, Douglas; Keller, Joel

    2016-09-01

    In traffic engineering, vehicle detectors are trained on limited datasets, resulting in poor accuracy when deployed in real-world surveillance applications. Annotating large-scale high-quality datasets is challenging. Typically, these datasets have limited diversity; they do not reflect the real-world operating environment. There is a need for a large-scale, cloud-based positive and negative mining process and a large-scale learning and evaluation system for the application of automatic traffic measurements and classification. The proposed positive and negative mining process addresses the quality of crowd sourced ground truth data through machine learning review and human feedback mechanisms. The proposed learning and evaluation system uses a distributed cloud computing framework to handle data-scaling issues associated with large numbers of samples and a high-dimensional feature space. The system is trained using AdaBoost on 1,000,000 Haar-like features extracted from 70,000 annotated video frames. The trained real-time vehicle detector achieves an accuracy of at least 95% for 1/2 and about 78% for 19/20 of the time when tested on ˜7,500,000 video frames. At the end of 2016, the dataset is expected to have over 1 billion annotated video frames.

  16. Numerical methods for large-scale, time-dependent partial differential equations

    NASA Technical Reports Server (NTRS)

    Turkel, E.

    1979-01-01

    A survey of numerical methods for time dependent partial differential equations is presented. The emphasis is on practical applications to large scale problems. A discussion of new developments in high order methods and moving grids is given. The importance of boundary conditions is stressed for both internal and external flows. A description of implicit methods is presented including generalizations to multidimensions. Shocks, aerodynamics, meteorology, plasma physics and combustion applications are also briefly described.

  17. Flashover of vacuum interfaces with many stages and large transit times

    SciTech Connect

    Smith, I.D.

    1997-04-01

    Methods are developed to calculate the effective breakdown levels and reliabilities of vacuum interfaces with many stages and (where applicable) large transit times. The method assumes that a breakdown equation like that of Martin describes the flashover of individual stages. The Nike and Saturn tubes are used to illustrate the results. Uncertainties in the single insulator breakdown equation are discussed, as are the implications of experience with Saturn and the two AIRIX injectors.

  18. Organizing the Extremely Large LSST Database forReal-Time Astronomical Processing

    SciTech Connect

    Becla, Jacek; Lim, Kian-Tat; Monkewitz, Serge; Nieto-Santisteban, Maria; Thakar, Ani; /Johns Hopkins U.

    2007-11-07

    The Large Synoptic Survey Telescope (LSST) will catalog billions of astronomical objects and trillions of sources, all of which will be stored and managed by a database management system. One of the main challenges is real-time alert generation. To generate alerts, up to 100K new difference detections have to be cross-correlated with the huge historical catalogs, and then further processed to prune false alerts. This paper explains the challenges, the implementation of the LSST Association Pipeline and the database organization strategies we are planning to use to meet the real-time requirements, including data partitioning, parallelization, and pre-loading.

  19. Time-sliced perturbation theory for large scale structure I: general formalism

    NASA Astrophysics Data System (ADS)

    Blas, Diego; Garny, Mathias; Ivanov, Mikhail M.; Sibiryakov, Sergey

    2016-07-01

    We present a new analytic approach to describe large scale structure formation in the mildly non-linear regime. The central object of the method is the time-dependent probability distribution function generating correlators of the cosmological observables at a given moment of time. Expanding the distribution function around the Gaussian weight we formulate a perturbative technique to calculate non-linear corrections to cosmological correlators, similar to the diagrammatic expansion in a three-dimensional Euclidean quantum field theory, with time playing the role of an external parameter. For the physically relevant case of cold dark matter in an Einstein-de Sitter universe, the time evolution of the distribution function can be found exactly and is encapsulated by a time-dependent coupling constant controlling the perturbative expansion. We show that all building blocks of the expansion are free from spurious infrared enhanced contributions that plague the standard cosmological perturbation theory. This paves the way towards the systematic resummation of infrared effects in large scale structure formation. We also argue that the approach proposed here provides a natural framework to account for the influence of short-scale dynamics on larger scales along the lines of effective field theory.

  20. Large lateral photovoltaic effect with ultrafast relaxation time in SnSe/Si junction

    SciTech Connect

    Wang, Xianjie; Zhao, Xiaofeng; Hu, Chang; Zhang, Yang; Song, Bingqian; Zhang, Lingli; Liu, Weilong; Lv, Zhe; Zhang, Yu; Sui, Yu; Tang, Jinke; Song, Bo

    2016-07-11

    In this paper, we report a large lateral photovoltaic effect (LPE) with ultrafast relaxation time in SnSe/p-Si junctions. The LPE shows a linear dependence on the position of the laser spot, and the position sensitivity is as high as 250 mV mm{sup −1}. The optical response time and the relaxation time of the LPE are about 100 ns and 2 μs, respectively. The current-voltage curve on the surface of the SnSe film indicates the formation of an inversion layer at the SnSe/p-Si interface. Our results clearly suggest that most of the excited-electrons diffuse laterally in the inversion layer at the SnSe/p-Si interface, which results in a large LPE with ultrafast relaxation time. The high positional sensitivity and ultrafast relaxation time of the LPE make the SnSe/p-Si junction a promising candidate for a wide range of optoelectronic applications.

  1. Real-time visualization of large volume datasets on standard PC hardware.

    PubMed

    Xie, Kai; Yang, Jie; Zhu, Y M

    2008-05-01

    In medical area, interactive three-dimensional volume visualization of large volume datasets is a challenging task. One of the major challenges in graphics processing unit (GPU)-based volume rendering algorithms is the limited size of texture memory imposed by current GPU architecture. We attempt to overcome this limitation by rendering only visible parts of large CT datasets. In this paper, we present an efficient, high-quality volume rendering algorithm using GPUs for rendering large CT datasets at interactive frame rates on standard PC hardware. We subdivide the volume dataset into uniform sized blocks and take advantage of combinations of early ray termination, empty-space skipping and visibility culling to accelerate the whole rendering process and render visible parts of volume data. We have implemented our volume rendering algorithm for a large volume data of 512 x 304 x 1878 dimensions (visible female), and achieved real-time performance (i.e., 3-4 frames per second) on a Pentium 4 2.4GHz PC equipped with NVIDIA Geforce 6600 graphics card ( 256 MB video memory). This method can be used as a 3D visualization tool of large CT datasets for doctors or radiologists.

  2. Interrelations between the perception of time and space in large-scale environments.

    PubMed

    Riemer, Martin; Hölzl, Rupert; Kleinböhl, Dieter

    2014-04-01

    Interactions between perceived temporal and spatial properties of external stimuli (e.g. duration and size) suggest common neural mechanisms underlying the perception of time and space. This conclusion, however, lacks support from studies in large-scale environments, showing that judgements on travelled distances and associated travel times are independent from each other. Here, we used a different approach to test whether the perception of travelled distances is influenced by the perception of time. Unlike previous studies, in which temporal and spatial judgements were related to the same experience of walking, we assessed time and distance perception in analogous, but separate versions of estimation and production tasks. In estimation tasks, participants estimated the duration of a presented sound (time) or the length of a travelled distance (space), and in production tasks, participants terminated a sound after a numerically specified duration (time) or covered a numerically specified distance (space). The results show systematic overestimation of time and underestimation of travelled distance, and the latter reflecting previously reported misperceptions of visual distance. Time and distance judgements were related within individuals for production, but not for estimation tasks. These results suggest that temporal information might constitute a probabilistic cue for path integration.

  3. Access Time of Emergency Vehicles Under the Condition of Street Blockages after a Large Earthquake

    NASA Astrophysics Data System (ADS)

    Hirokawa, N.; Osaragi, T.

    2016-09-01

    The previous studies have been carried out on accessibility in daily life. However it is an important issue to improve the accessibility of emergency vehicles after a large earthquake. In this paper, we analyzed the accessibility of firefighters by using a microscopic simulation model immediately after a large earthquake. More specifically, we constructed the simulation model, which describes the property damage, such as collapsed buildings, street blockages, outbreaks of fires, and fire spreading, and the movement of firefighters from fire stations to the locations of fires in a large-scale earthquake. Using this model, we analyzed the influence of the street-blockage on the access time of firefighters. In case streets are blocked according to property damage simulation, the result showed the average access time is more than 10 minutes in the outskirts of the 23 wards of Tokyo, and there are some firefighters arrive over 20 minutes at most. Additionally, we focused on the alternative routes and proposed that volunteers collect information on street blockages to improve the accessibility of firefighters. Finally we demonstrated that access time of firefighters can be reduced to the same level as the case no streets were blocked if 0.3% of residents collected information in 10 minutes.

  4. Incipient multiple fault diagnosis in real time with applications to large-scale systems

    SciTech Connect

    Chung, H.Y.; Bien, Z.; Park, J.H.; Seon, P.H. . Dept. of Electrical Engineering)

    1994-08-01

    By using a modified signed directed graph (SDG) together with the distributed artificial neutral networks and a knowledge-based system, a method of incipient multi-fault diagnosis is presented for large-scale physical systems with complex pipes and instrumentations such as valves, actuators, sensors, and controllers. The proposed method is designed so as to (1) make a real-time incipient fault diagnosis possible for large-scale systems, (2) perform the fault diagnosis not only in the steady-state case but also in the transient case as well by using a concept of fault propagation time, which is newly adopted in the SDG model, (3) provide with highly reliable diagnosis results and explanation capability of faults diagnosed as in an expert system, and (4) diagnose the pipe damage such as leaking, break, or throttling. This method is applied for diagnosis of a pressurizer in the Kori Nuclear Power Plant (NPP) unit 2 in Korea under a transient condition, and its result is reported to show satisfactory performance of the method for the incipient multi-fault diagnosis of such a large-scale system in a real-time manner.

  5. A sputnik IV saga

    NASA Astrophysics Data System (ADS)

    Lundquist, Charles A.

    2009-12-01

    The Sputnik IV launch occurred on May 15, 1960. On May 19, an attempt to deorbit a 'space cabin' failed and the cabin went into a higher orbit. The orbit of the cabin was monitored and Moonwatch volunteer satellite tracking teams were alerted to watch for the vehicle demise. On September 5, 1962, several team members from Milwaukee, Wisconsin made observations starting at 4:49 a.m. of a fireball following the predicted orbit of Sputnik IV. Requests went out to report any objects found under the fireball path. An early morning police patrol in Manitowoc had noticed a metal object on a street and had moved it to the curb. Later the officers recovered the object and had it dropped off at the Milwaukee Journal. The Moonwarch team got the object and reported the situation to Moonwatch Headquarters at the Smithsonian Astrophysical Observatory. A team member flew to Cambridge with the object. It was a solid, 9.49 kg piece of steel with a slag-like layer attached to it. Subsequent analyses showed that it contained radioactive nuclei produced by cosmic ray exposure in space. The scientists at the Observatory quickly recognized that measurements of its induced radioactivity could serve as a calibration for similar measurements of recently fallen nickel-iron meteorites. Concurrently, the Observatory directorate informed government agencies that a fragment from Sputnik IV had been recovered. Coincidently, a debate in the UN Committee on Peaceful Uses of Outer Space involved the issue of liability for damage caused by falling satellite fragments. On September 12, the Observatory delivered the bulk of the fragment to the US Delegation to the UN. Two days later, the fragment was used by US Ambassador Francis Plimpton as an exhibit that the time had come to agree on liability for damage from satellite debris. He offered the Sputnik IV fragment to USSR Ambassador P.D. Morozov, who refused the offer. On October 23, Drs. Alla Massevitch and E.K. Federov of the USSR visited the

  6. Subsurface Supergranular Vertical Flows as Measured Using Large Distance Separations in Time-Distance Helioseismology

    NASA Technical Reports Server (NTRS)

    Duvall, T. L., Jr.; Hanasoge, S. M.

    2012-01-01

    As large-distance rays (say, 10-24 deg) approach the solar surface approximately vertically, travel times measured from surface pairs for these large separations are mostly sensitive to vertical flows, at least for shallow flows within a few Mm of the solar surface. All previous analyses of supergranulation have used smaller separations and have been hampered by the difficulty of separating the horizontal and vertical flow components. We find that the large separation travel times associated with upergranulation cannot be studied using the standard phase-speed filters of time-distance helioseismology. These filters, whose use is based upon a refractive model of the perturbations,reduce the resultant travel time signal by at least an order of magnitude at some distances. More effective filters are derived. Modeling suggests that the center-annulus travel time difference in the separation range 10-24 deg is insensitive to the horizontally diverging flow from the centers of the supergranules and should lead to a constant signal from the vertical flow. Our measurement of this quantity for the average supergranule, 5.1 s, is constant over the distance range. This magnitude of signal cannot be caused by the level of upflow at cell centers seen at the photosphere of 10 m/s extended in depth. It requires the vertical flow to increase with depth. A simple Gaussian model of the increase with depth implies a peak upward flow of 240 m/s at a depth of 2.3 Mm and a peak horizontal flow of 700 m/s at a depth of 1.6 Mm.

  7. TIMESERIESSTREAMING.VI: LabVIEW program for reliable data streaming of large analog time series

    NASA Astrophysics Data System (ADS)

    Czerwinski, Fabian; Oddershede, Lene B.

    2011-02-01

    With modern data acquisition devices that work fast and very precise, scientists often face the task of dealing with huge amounts of data. These need to be rapidly processed and stored onto a hard disk. We present a LabVIEW program which reliably streams analog time series of MHz sampling. Its run time has virtually no limitation. We explicitly show how to use the program to extract time series from two experiments: For a photodiode detection system that tracks the position of an optically trapped particle and for a measurement of ionic current through a glass capillary. The program is easy to use and versatile as the input can be any type of analog signal. Also, the data streaming software is simple, highly reliable, and can be easily customized to include, e.g., real-time power spectral analysis and Allan variance noise quantification. Program summaryProgram title: TimeSeriesStreaming.VI Catalogue identifier: AEHT_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEHT_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 250 No. of bytes in distributed program, including test data, etc.: 63 259 Distribution format: tar.gz Programming language: LabVIEW ( http://www.ni.com/labview/) Computer: Any machine running LabVIEW 8.6 or higher Operating system: Windows XP and Windows 7 RAM: 60-360 Mbyte Classification: 3 Nature of problem: For numerous scientific and engineering applications, it is highly desirable to have an efficient, reliable, and flexible program to perform data streaming of time series sampled with high frequencies and possibly for long time intervals. This type of data acquisition often produces very large amounts of data not easily streamed onto a computer hard disk using standard methods. Solution method: This LabVIEW program is developed to directly

  8. Real-time, large scale optimization of water network systems using a subdomain approach.

    SciTech Connect

    van Bloemen Waanders, Bart Gustaaf; Biegler, Lorenz T.; Laird, Carl Damon

    2005-03-01

    Certain classes of dynamic network problems can be modeled by a set of hyperbolic partial differential equations describing behavior along network edges and a set of differential and algebraic equations describing behavior at network nodes. In this paper, we demonstrate real-time performance for optimization problems in drinking water networks. While optimization problems subject to partial differential, differential, and algebraic equations can be solved with a variety of techniques, efficient solutions are difficult for large network problems with many degrees of freedom and variable bounds. Sequential optimization strategies can be inefficient for this problem due to the high cost of computing derivatives with respect to many degrees of freedom. Simultaneous techniques can be more efficient, but are difficult because of the need to solve a large nonlinear program; a program that may be too large for current solver. This study describes a dynamic optimization formulation for estimating contaminant sources in drinking water networks, given concentration measurements at various network nodes. We achieve real-time performance by combining an efficient large-scale nonlinear programming algorithm with two problem reduction techniques. D Alembert's principle can be applied to the partial differential equations governing behavior along the network edges (distribution pipes). This allows us to approximate the time-delay relationships between network nodes, removing the need to discretize along the length of the pipes. The efficiency of this approach alone, however, is still dependent on the size of the network and does not scale indefinitely to larger network models. We further reduce the problem size with a subdomain approach and solve smaller inversion problems using a geographic window around the area of contamination. We illustrate the effectiveness of this overall approach and these reduction techniques on an actual metropolitan water network model.

  9. Time Domain Science and Fundamental Physics with the Next-generation Very Large Array

    NASA Astrophysics Data System (ADS)

    Demorest, Paul; Bower, Geoffrey C.; ngVLA Time Domain/Physics Science Working Group

    2017-01-01

    The Next-generation Very Large Array (ngVLA) is a design concept for a future large-area radio telescope under development by the NRAO and interested members of the scientific community. The approximate ngVLA specifications call for a frequency range of ~1--116 GHz, ten times the effective collecting area and moderately increased field of view versus the current VLA, and an array configuration consisting of a dense (~km-scale) array core with some baselines extending out to hundreds of km. This instrument will enable new discoveries in many diverse areas of research relevant to modern astronomy; our group has explored the impact the ngVLA will have in time domain astronomy and fundamental physics.Here we present several key science topics considered as part of this work. These include: Searching for and timing radio pulsars at the galactic center -- the frequency coverage and sensitivity of the ngVLA will allow detection of highly-scattered pulsars near Sgr A*. Monitoring these sources will permit unprecedented tests of general relativity. Detecting and characterizing explosive transient sources -- electromagnetic observations of gravitational-wave sources provide complementary information to the GW signals themselves. Observations across the wide frequency range spanned by the ngVLA are critical for energy calorimetry of these events. Finally, with sufficient long-baseline coverage, novel astrometric approaches to cosmology become possible, by watching the expansion of the universe in real time through correlated proper motions of many extragalactic radio sources.

  10. Physics of the environment: possible Sumatra Tsunami warning times for large animals in Sri Lanka

    NASA Astrophysics Data System (ADS)

    Browning, David G.; Scheifele, Peter M.; Vonwinkle, William A.

    2005-04-01

    There has previously been significant anecdotal evidence that animals can anticipate or sense seismic events. It is known that large animals, specifically elephants, sense and utilize low frequency sound. The object of this paper is to estimate the possible warning times that large animals in Sri Lanka could have had of the Sumatra Tsunami, assuming they could sense low frequency wave transmission from the initial earthquake arriving by either atmospheric, ocean, or bottom paths. The atmospheric path appears to be the least efficient due to relatively high attenuation and poor coupling to the source. It would also give the shortest warning time: approximately 30 minutes. The ocean path via the deep sound channel, which has been shown by a previous Bermuda experiment to be an efficient means of coupling seismic energy to an island, would give a warning time of more than 1.5 hours. The bottom path(s), which gave strong received signals at a Sri Lanka seismic station, would give a warning time of about 2 hours. These estimates should provide a context for animal behavior reports.

  11. 20 CFR 655.1114 - Element IV-What are the timely and significant steps an H-1C employer must take to recruit and...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... nurses. Such monetary incentives may be based on actions by nurses such as: Instituting innovations to... in paragraphs (b)(1) and (b)(2)(i) through (iv). ETA will review the explanation and documentation... subject to review by the BALCA, upon the request of an interested party; such review shall be limited to...

  12. Real-time distortion correction system of large-field optical display equipment based on FPGA

    NASA Astrophysics Data System (ADS)

    Zheng, Chun; Zhou, Yongjun; Zheng, Yongrui; Li, Jie

    2011-08-01

    Current distortion correction systems can not meet the requirements of the large-field optical display equipment because of small field, low resolution, poor real-time property and commonality. "The symmetrical transform" and "the improved bilinear interpolation" were proposed. The general system scheme was designed and implemented in the Virtex-5 FPGA devices. The appropriate data structure of the look-up table was adopted and the optimized scheme for the input memory named "the double even-odd cache" was put forward. MIG (Memory Interface Generator) software tool was utilized to control DDR2 SDRAM and DSP48E was used. The real-time distortion correction system of the large-field optical display equipment was accomplished. The experimental result shows that the correction system can correct the large-field and high-resolution (1280x1024) video image (60 frames per second). The system delays only 1.48ms while the deviation in precision is less than 9' and has the well commonality.

  13. Electron Recoil rejection by decay time measurement in large liquid Xenon detectors

    NASA Astrophysics Data System (ADS)

    Namwongsa, P.; Banjongkan, A.; Chen, X.; Giboni, K. L.; Ji, X.; Kobdaj, C.; Kusano, H.; Yupeng, Y.

    2017-04-01

    Very large Liquid Xenon (LXe) Time Projection Chambers (TPC) are employed to search for Dark Matter (DM). The DM particles are supposed to interact with the whole nucleus, compared to background of γ-rays, which interact with the electrons. Therefore, DM signals are caused by Nuclear Recoil (NR) instead of the Electron Recoils (ER). In ER and NR events differ in pulse shape since the ratios of light from direct scintillation and recombination are different. To discriminate against residual ER events would be possible if one can distinguish the differences in decay times. This method can be successfully applied in Liquid Argon TPCs. In LXe, however, it is generally assumed that these differences are too small to be distinguished at low energies. The easiest algorithm of Pulse Shape Discrimination (PSD) distinguishes the event type based on the number of photons emitted much later than the longest decay time. At low energies too much of the timing information is lost, and this method does not perform well. However, the timing of all photons does contain sufficient information. If we use sufficiently fast PMTs, have a large enough bandwidth in the Front End electronics, and avoid reflections then we should reach a background rejection better than 10-2 even at 2 keVee. In our Decay Time Measurement (DTM) method the decay curves are compared with a model on an event by event basis. Statistically this is independent from the charge over light (`S2/S1') cut normally applied in Dual Phase detectors. Applying both rejection mechanisms a LXeTPC can become `quasi background free'.

  14. The simulated features of heliospheric cosmic-ray modulation with a time-dependent drift model. IV - The role of heliospheric neutral sheet deformation

    NASA Technical Reports Server (NTRS)

    Le Roux, J. A.; Potgieter, M. S.

    1992-01-01

    Previous calculations with a time-dependent drift model revealed the model to be less successful in describing time-dependent modulation during periods of moderate to large solar activity. In this paper, it is argued that a major reason for this is that the previously used wavy heliospheric neutral sheet (HNS) description was based on an idealized HNS not subject to any spatial evolution while propagating radially outward. It is suggested that the deformation and compression of HNS wave peaks will lead to significant increases in the crossfield diffusion across these peaks (short-circuiting). The cosmic rays will effectively experience reduced tilt angles and therefore a reduction in the integrated HNS modulation effect between an observer and the heliospheric boundary. During periods of moderate to large solar activity these HNS deformation processes are progressively more frequent and should lead to a significant reduction in time-dependent modulation as predicted by drift models. Calculations done with radially propagating tilt angles that effectively decrease with radial distance give the expected reduction which improves the general description of modulation from 1987-1988.

  15. Sorption of selenium(IV) and selenium(VI) to mackinawite (FeS): effect of contact time, extent of removal, sorption envelopes.

    PubMed

    Han, Dong Suk; Batchelor, Bill; Abdel-Wahab, Ahmed

    2011-02-15

    Higher concentrations (127, 253 μM) of Se(IV) at pH 8 were completely removed by 0.5 g/L FeS within 120 min. Removal of Se(VI) by FeS at pH 8 was less extensive than removal of Se(IV). Only 10% of the Se(VI) was removed by 1 g/L FeS within 1h. Removal patterns for Se by FeS depend on pH. Removal patterns of Se at pH 7 and pH 8 were best described by BET models for Se(IV) and Freundlich models for Se(VI), while removal patterns of both at pH 9 and 10 were best described by Langmuir models. Sulfate at 1 and 10 mM had negligible effect on removal of Se(IV) by FeS, while sulfate had little effect on removal of Se(VI) by FeS, but there was some indication that sulfate promoted removal of Se(VI) at intermediate concentrations. The test for the effect of pH on sorption of Se(IV) by FeS showed nearly complete removal at all but the high initial pH. When pH was raised back to initial value, greater removals were observed than initially. Mixtures of Se(VI) and FeS showed moderate removal at low pH, a minimum removal near pH 6 and nearly complete removal at high pH. Very high stability was observed with negligible release as pH decreased.

  16. Exploring the limiting timing resolution for large volume CZT detectors with waveform analysis.

    PubMed

    Meng, L J; He, Z

    2005-09-11

    This paper presents a study for exploring the limiting timing resolution that can be achieved with a large volume 3-D position sensitive CZT detector. The interaction timing information was obtained by fitting the measured cathode waveforms to pre-defined waveform models. We compared the results from using several different waveform models. Timing resolutions, of ~9.5 ns for 511 keV full-energy events and ~11.6 ns for all detected events with energy deposition above 250 keV, were achieved with a detailed modeling of the cathode waveform as a function of interaction location and energy deposition. This detailed modeling also allowed us to derive a theoretical lower bound for the error on estimated interaction timing. Both experimental results and theoretical predications matched well, which indicated that the best timing resolution achievable in the 1 cm(3) CZT detector tested is ~10 ns. It is also showed that the correlation between sampled amplitudes in cathode waveforms is an important limiting factor for the achievable timing resolution.

  17. Exploring the limiting timing resolution for large volume CZT detectors with waveform analysis

    PubMed Central

    Meng, L.J.; He, Z.

    2016-01-01

    This paper presents a study for exploring the limiting timing resolution that can be achieved with a large volume 3-D position sensitive CZT detector. The interaction timing information was obtained by fitting the measured cathode waveforms to pre-defined waveform models. We compared the results from using several different waveform models. Timing resolutions, of ~9.5 ns for 511 keV full-energy events and ~11.6 ns for all detected events with energy deposition above 250 keV, were achieved with a detailed modeling of the cathode waveform as a function of interaction location and energy deposition. This detailed modeling also allowed us to derive a theoretical lower bound for the error on estimated interaction timing. Both experimental results and theoretical predications matched well, which indicated that the best timing resolution achievable in the 1 cm3 CZT detector tested is ~10 ns. It is also showed that the correlation between sampled amplitudes in cathode waveforms is an important limiting factor for the achievable timing resolution. PMID:28260808

  18. Children With Autism Spectrum Disorder and Screen Time: Results From a Large, Nationally Representative US Study.

    PubMed

    Montes, Guillermo

    2016-03-01

    To test the hypotheses that children with autism spectrum disorder (ASD) have higher screen time than other children on a US nationally representative sample and that children with ASD are overrepresented among children who exceed the American Academy of Pediatrics (AAP) screen time recommendation (2 hours or less a day). The National Survey of Children's Health 2011-2012, a nationally representative survey, asked parents to report their child's (aged 6-17 years) average daily media usage. The ASD subpopulation (n = 1393) was compared to children without ASD (non-ASD, n = 64,163). Differences were compared by design-corrected F tests. Regression models were estimated for both groups separately. Adjusted Wald tests were used to rigorously test the hypotheses. More than half of US children exceed the AAP screen time recommendation. Compared to non-ASD, children with ASD had similar amounts of total screen time (3.21 hours per day vs 3.46 hours per day; P > .05), media (TV/video) time, and computer/mobile device leisure time. Children with ASD have a milder age gradient than the general population on computer/mobile device usage. Children with ASD were proportionally represented among high users (more than 2 hours per day). Data did not support hypotheses. In a large, nationally representative US sample, there was no evidence that children with ASD differ in their screen time habits from other children. Both groups have high screen time use. Caution should be exercised before assuming that children with ASD are at higher risk of exceeding AAP screen time recommendations. Efforts to promote adherence to the recommendation are needed, but they should neither target nor exclude children with ASD. Copyright © 2016 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

  19. Large Observatory For X-ray Timing (LOFT-P): A Probe-Class Mission Concept

    NASA Astrophysics Data System (ADS)

    Wilson-Hodge, Colleen A.; Ray, Paul S.; Chakrabarty, Deepto; Feroci, Marco

    2016-04-01

    LOFT-P is a mission concept for a NASA Astrophysics Probe-Class (<$1B) X-ray timing mission, based on the LOFT M-class concept originally proposed to ESA’s M3 and M4 calls. LOFT-P requires very large collecting area, high time resolution, good spectral resolution,broadband spectral coverage (2-30 keV), highly flexible scheduling, and an ability to detect and respond promptly to time-critical targets of opportunity. It addresses science questions such as: What is the equation of state of ultra dense matter? What are the effects of strong gravity on matter spiraling into black holes? It would be optimized for sub-millisecond timing of bright Galactic X-ray sources including X-ray bursters, black hole binaries, and magnetars to study phenomena at the natural timescales of neutron star surfaces and black hole event horizons and to measure mass and spin of black holes. These measurements are synergistic to imaging and high-resolution spectroscopy instruments, addressing much smaller distance scales than are possible without very long baseline X-ray interferometry, and using complementary techniques to address the geometry and dynamics of emission regions. LOFT-P would have an effective area of >6 m2, >10x that of the highly successful Rossi X-ray Timing Explorer (RXTE). A sky monitor (~2-50 keV) acts as a trigger for pointed observations, providing high duty cycle, high time resolution monitoring of the X-ray sky with ~20 times the sensitivity of the RXTE All-Sky Monitor, enabling multi-wavelength and multi-messenger studies. A probe-class mission concept would employ lightweight collimator technology and large-area solid-state detectors, segmented into pixels or strips, technologies which have been recently greatly advanced during the ESA M-3 Phase A study of LOFT. Given the large community interested in LOFT (>800 supporters), the scientific productivity of this mission is expected to be very high, similar to or greater than RXTE (~2000 refereed publications.) In

  20. Very Large Inflammatory Odontogenic Cyst with Origin on a Single Long Time Traumatized Lower Incisor

    PubMed Central

    Freitas, Filipe; Andre, Saudade; Moreira, Andre; Carames, Joao

    2015-01-01

    One of the consequences of traumatic injuries is the chance of aseptic pulp necrosis to occur which in time may became infected and give origin to periapical pathosis. Although the apical granulomas and cysts are a common condition, there appearance as an extremely large radiolucent image is a rare finding. Differential diagnosis with other radiographic-like pathologies, such as keratocystic odontogenic tumour or unicystic ameloblastoma, is mandatory. The purpose of this paper is to report a very large radicular cyst caused by a single mandibular incisor traumatized long back, in a 60-year-old male. Medical and clinical histories were obtained, radiographic and cone beam CT examinations performed and an initial incisional biopsy was done. The final decision was to perform a surgical enucleation of a lesion, 51.4 mm in length. The enucleated tissue biopsy analysis was able to render the diagnosis as an inflammatory odontogenic cyst. A 2 year follow-up showed complete bone recovery. PMID:26393219

  1. The effect of access time on online quiz performance in large biology lecture courses.

    PubMed

    Metz, Anneke M

    2008-05-01

    To better understand the dynamics of online student test taking, including the likelihood of cheating by large numbers of students, we examined test-taking patterns and outcomes of weekly online quizzes in two large undergraduate biology lecture courses. Students taking a quiz late in a 1-3-day quiz access period performed 10-15% worse on quizzes than the students who completed the quiz early. Quiz access time was also negatively correlated with performance in other course components and course grades. These patterns suggest that academic dishonesty was not a determinant in unsupervised online quiz performance. Students generally completed quizzes in late afternoon or evening hours, but students who completed quizzes between midnight and 8 a.m. had significantly lower quiz grades than their peers. In addition, upper-division students were more likely to characterize weekly online quizzes as more helpful for their learning than the lower-division students.

  2. Overcoming autocorrelation biases for causal inference in large nonlinear geoscientific time series datasets

    NASA Astrophysics Data System (ADS)

    Runge, Jakob; Sejdinovic, Dino; Flaxman, Seth

    2017-04-01

    Causal discovery methods for geoscientific time series datasets aim at detecting potentially causal statistical associations that cannot be explained by other variables in the dataset. A large-scale complex system like the Earth presents major challenges for methods such as Granger causality. In particular, its high dimensionality and strong autocorrelations lead to low detection power, distorting biases, and unreliable hypothesis tests. Here we introduce a reliable method that outperforms current approaches in detection power and overcomes detection biases, making it suitable to detect even weak causal signals in large-scale geoscientific datasets. We illustrate the method's capabilities on the global surface-pressure system where we unravel spurious associations and find several potentially causal links that are difficult to detect with standard methods, focusing in particular on drivers of the NAO.

  3. Time Discounting and Credit Market Access in a Large-Scale Cash Transfer Programme

    PubMed Central

    Handa, Sudhanshu; Martorano, Bruno; Halpern, Carolyn; Pettifor, Audrey; Thirumurthy, Harsha

    2017-01-01

    Summary Time discounting is thought to influence decision-making in almost every sphere of life, including personal finances, diet, exercise and sexual behavior. In this article we provide evidence on whether a national poverty alleviation program in Kenya can affect inter-temporal decisions. We administered a preferences module as part of a large-scale impact evaluation of the Kenyan Government’s Cash Transfer for Orphans and Vulnerable Children. Four years into the program we find that individuals in the treatment group are only marginally more likely to wait for future money, due in part to the erosion of the value of the transfer by inflation. However among the poorest households for whom the value of transfer is still relatively large we find significant program effects on the propensity to wait. We also find strong program effects among those who have access to credit markets though the program itself does not improve access to credit. PMID:28260842

  4. Time Discounting and Credit Market Access in a Large-Scale Cash Transfer Programme.

    PubMed

    Handa, Sudhanshu; Martorano, Bruno; Halpern, Carolyn; Pettifor, Audrey; Thirumurthy, Harsha

    2016-06-01

    Time discounting is thought to influence decision-making in almost every sphere of life, including personal finances, diet, exercise and sexual behavior. In this article we provide evidence on whether a national poverty alleviation program in Kenya can affect inter-temporal decisions. We administered a preferences module as part of a large-scale impact evaluation of the Kenyan Government's Cash Transfer for Orphans and Vulnerable Children. Four years into the program we find that individuals in the treatment group are only marginally more likely to wait for future money, due in part to the erosion of the value of the transfer by inflation. However among the poorest households for whom the value of transfer is still relatively large we find significant program effects on the propensity to wait. We also find strong program effects among those who have access to credit markets though the program itself does not improve access to credit.

  5. Intelligent Virtual Station (IVS)

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Intelligent Virtual Station (IVS) is enabling the integration of design, training, and operations capabilities into an intelligent virtual station for the International Space Station (ISS). A viewgraph of the IVS Remote Server is presented.

  6. Intelligent Virtual Station (IVS)

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Intelligent Virtual Station (IVS) is enabling the integration of design, training, and operations capabilities into an intelligent virtual station for the International Space Station (ISS). A viewgraph of the IVS Remote Server is presented.

  7. A class of large time step Godunov schemes for hyperbolic conservation laws and applications

    NASA Astrophysics Data System (ADS)

    Qian, ZhanSen; Lee, Chun-Hian

    2011-08-01

    A large time step (LTS) Godunov scheme firstly proposed by LeVeque is further developed in the present work and applied to Euler equations. Based on the analysis of the computational performances of LeVeque's linear approximation on wave interactions, a multi-wave approximation on rarefaction fan is proposed to avoid the occurrences of rarefaction shocks in computations. The developed LTS scheme is validated using 1-D test cases, manifesting high resolution for discontinuities and the capability of maintaining computational stability when large CFL numbers are imposed. The scheme is then extended to multidimensional problems using dimensional splitting technique; the treatment of boundary condition for this multidimensional LTS scheme is also proposed. As for demonstration problems, inviscid flows over NACA0012 airfoil and ONERA M6 wing with given swept angle are simulated using the developed LTS scheme. The numerical results reveal the high resolution nature of the scheme, where the shock can be captured within 1-2 grid points. The resolution of the scheme would improve gradually along with the increasing of CFL number under an upper bound where the solution becomes severely oscillating across the shock. Computational efficiency comparisons show that the developed scheme is capable of reducing the computational time effectively with increasing the time step (CFL number).

  8. 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.

  9. Large time-step stability of explicit one-dimensional advection schemes

    NASA Technical Reports Server (NTRS)

    Leonard, B. P.

    1993-01-01

    There is a wide-spread belief that most explicit one-dimensional advection schemes need to satisfy the so-called 'CFL condition' - that the Courant number, c = udelta(t)/delta(x), must be less than or equal to one, for stability in the von Neumann sense. This puts severe limitations on the time-step in high-speed, fine-grid calculations and is an impetus for the development of implicit schemes, which often require less restrictive time-step conditions for stability, but are more expensive per time-step. However, it turns out that, at least in one dimension, if explicit schemes are formulated in a consistent flux-based conservative finite-volume form, von Neumann stability analysis does not place any restriction on the allowable Courant number. Any explicit scheme that is stable for c is less than 1, with a complex amplitude ratio, G(c), can be easily extended to arbitrarily large c. The complex amplitude ratio is then given by exp(- (Iota)(Nu)(Theta)) G(delta(c)), where N is the integer part of c, and delta(c) = c - N (less than 1); this is clearly stable. The CFL condition is, in fact, not a stability condition at all, but, rather, a 'range restriction' on the 'pieces' in a piece-wise polynomial interpolation. When a global view is taken of the interpolation, the need for a CFL condition evaporates. A number of well-known explicit advection schemes are considered and thus extended to large delta(t). The analysis also includes a simple interpretation of (large delta(t)) total-variation-diminishing (TVD) constraints.

  10. Incorporating Real-time Earthquake Information into Large Enrollment Natural Disaster Course Learning

    NASA Astrophysics Data System (ADS)

    Furlong, K. P.; Benz, H.; Hayes, G. P.; Villasenor, A.

    2010-12-01

    Although most would agree that the occurrence of natural disaster events such as earthquakes, volcanic eruptions, and floods can provide effective learning opportunities for natural hazards-based courses, implementing compelling materials into the large-enrollment classroom environment can be difficult. These natural hazard events derive much of their learning potential from their real-time nature, and in the modern 24/7 news-cycle where all but the most devastating events are quickly out of the public eye, the shelf life for an event is quite limited. To maximize the learning potential of these events requires that both authoritative information be available and course materials be generated as the event unfolds. Although many events such as hurricanes, flooding, and volcanic eruptions provide some precursory warnings, and thus one can prepare background materials to place the main event into context, earthquakes present a particularly confounding situation of providing no warning, but where context is critical to student learning. Attempting to implement real-time materials into large enrollment classes faces the additional hindrance of limited internet access (for students) in most lecture classrooms. In Earth 101 Natural Disasters: Hollywood vs Reality, taught as a large enrollment (150+ students) general education course at Penn State, we are collaborating with the USGS’s National Earthquake Information Center (NEIC) to develop efficient means to incorporate their real-time products into learning activities in the lecture hall environment. Over time (and numerous events) we have developed a template for presenting USGS-produced real-time information in lecture mode. The event-specific materials can be quickly incorporated and updated, along with key contextual materials, to provide students with up-to-the-minute current information. In addition, we have also developed in-class activities, such as student determination of population exposure to severe ground

  11. Optical pseudocolor image enhancement with real-time large screen display

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin; Liu, Hua-Kuang

    1988-01-01

    A real-time broadband pseudocolor image enhancement technique using a liquid crystal television spatial light modulator (LCTV SLM) is described. Three different schemes to modulate the gray-scale disribution of an input scene by an LCTV SLM through varying the orientations of its analyzer are presented. These schemes are incorporated into a compact white light optical projection system that is able to display, on a large screen, broadband pseudocolor images of real-world input scenes. Experimental results demonstrating the feasibility of the technique are reported.

  12. Large-time behavior of solutions to a thermo-diffusion system with Smoluchowski interactions

    NASA Astrophysics Data System (ADS)

    Aiki, Toyohiko; Muntean, Adrian

    2017-09-01

    We prove the large time behavior of solutions to a coupled thermo-diffusion arising in the modeling of the motion of hot colloidal particles in porous media. Additionally, we also ensure the uniqueness of solutions of the target problem. The main mathematical difficulty is due to the presence in the right-hand side of the equations of products between temperature and concentration gradients. Such terms mimic the so-called thermodynamic Soret and Dufour effects. These are cross-coupling terms emphasizing in this context a strong interplay between heat conduction and molecular diffusion.

  13. Space-Time Controls on Carbon Sequestration Over Large-Scale Amazon Basin

    NASA Technical Reports Server (NTRS)

    Smith, Eric A.; Cooper, Harry J.; Gu, Jiujing; Grose, Andrew; Norman, John; daRocha, Humberto R.; Starr, David O. (Technical Monitor)

    2002-01-01

    A major research focus of the LBA Ecology Program is an assessment of the carbon budget and the carbon sequestering capacity of the large scale forest-pasture system that dominates the Amazonia landscape, and its time-space heterogeneity manifest in carbon fluxes across the large scale Amazon basin ecosystem. Quantification of these processes requires a combination of in situ measurements, remotely sensed measurements from space, and a realistically forced hydrometeorological model coupled to a carbon assimilation model, capable of simulating details within the surface energy and water budgets along with the principle modes of photosynthesis and respiration. Here we describe the results of an investigation concerning the space-time controls of carbon sources and sinks distributed over the large scale Amazon basin. The results are derived from a carbon-water-energy budget retrieval system for the large scale Amazon basin, which uses a coupled carbon assimilation-hydrometeorological model as an integrating system, forced by both in situ meteorological measurements and remotely sensed radiation fluxes and precipitation retrieval retrieved from a combination of GOES, SSM/I, TOMS, and TRMM satellite measurements. Brief discussion concerning validation of (a) retrieved surface radiation fluxes and precipitation based on 30-min averaged surface measurements taken at Ji-Parana in Rondonia and Manaus in Amazonas, and (b) modeled carbon fluxes based on tower CO2 flux measurements taken at Reserva Jaru, Manaus and Fazenda Nossa Senhora. The space-time controls on carbon sequestration are partitioned into sets of factors classified by: (1) above canopy meteorology, (2) incoming surface radiation, (3) precipitation interception, and (4) indigenous stomatal processes varied over the different land covers of pristine rainforest, partially, and fully logged rainforests, and pasture lands. These are the principle meteorological, thermodynamical, hydrological, and biophysical

  14. Space-Time Controls on Carbon Sequestration Over Large-Scale Amazon Basin

    NASA Technical Reports Server (NTRS)

    Smith, Eric A.; Cooper, Harry J.; Gu, Jiujing; Grose, Andrew; Norman, John; daRocha, Humberto R.; Starr, David O. (Technical Monitor)

    2002-01-01

    A major research focus of the LBA Ecology Program is an assessment of the carbon budget and the carbon sequestering capacity of the large scale forest-pasture system that dominates the Amazonia landscape, and its time-space heterogeneity manifest in carbon fluxes across the large scale Amazon basin ecosystem. Quantification of these processes requires a combination of in situ measurements, remotely sensed measurements from space, and a realistically forced hydrometeorological model coupled to a carbon assimilation model, capable of simulating details within the surface energy and water budgets along with the principle modes of photosynthesis and respiration. Here we describe the results of an investigation concerning the space-time controls of carbon sources and sinks distributed over the large scale Amazon basin. The results are derived from a carbon-water-energy budget retrieval system for the large scale Amazon basin, which uses a coupled carbon assimilation-hydrometeorological model as an integrating system, forced by both in situ meteorological measurements and remotely sensed radiation fluxes and precipitation retrieval retrieved from a combination of GOES, SSM/I, TOMS, and TRMM satellite measurements. Brief discussion concerning validation of (a) retrieved surface radiation fluxes and precipitation based on 30-min averaged surface measurements taken at Ji-Parana in Rondonia and Manaus in Amazonas, and (b) modeled carbon fluxes based on tower CO2 flux measurements taken at Reserva Jaru, Manaus and Fazenda Nossa Senhora. The space-time controls on carbon sequestration are partitioned into sets of factors classified by: (1) above canopy meteorology, (2) incoming surface radiation, (3) precipitation interception, and (4) indigenous stomatal processes varied over the different land covers of pristine rainforest, partially, and fully logged rainforests, and pasture lands. These are the principle meteorological, thermodynamical, hydrological, and biophysical

  15. Interim PET Scans in Diffuse Large B-Cell Lymphoma: Is It Ready for Prime Time?

    PubMed

    Bolshinsky, Maital; Nabhan, Chadi

    2016-12-01

    Prognostication of patients with diffuse large B-cell lymphoma (DLBCL) has improved in the past decade with a variety of clinical, morphologic, molecular, and radiographic methods. Comparable to data on the value of interim positron emission tomography (I-PET) in Hodgkin lymphoma, several retrospective and prospective studies are attempting to assess the value of I-PET scanning in DLBCL patients. In this review, we briefly describe and analyze the various prognostic methods in DLBCL with specific focus on the value of I-PET scanning in this disease. This is a timely analysis, as tailoring therapies based on prognosis at diagnosis are becoming of increased investigational interest.

  16. Characterizing the frequency response curve of large rooms in the short and long time regimes

    NASA Astrophysics Data System (ADS)

    Klales, Anna; Pittman, Suzanne; Barr, Matthew; Borunda, Mario; Heller, Eric

    2012-02-01

    Room acoustics can be modeled by real Gaussian statistics, corresponding to randomized ray trajectories and characterized for instance by the reverberation time T60 (free field to decay by 60 decibels) which is independent of position or source point in a room. In his 1954 paper, Manfred Schroeder found universal statistical features of the steady state frequency response curve of large rooms, based upon the assumption of Gaussian probability distributions of the pressure. For example, he found the standard deviation from the mean level is 11 decibels for any concert hall, regardless of the shape of the room or its T60, within reasonable limits. Using semi-classical and numerical methods, we find non-universal (room dependent) corrections to Schroeder's universal results for the statistics of the frequency response curve. Along with corrections to the steady-state frequency response, we present the behavior of the frequency response curve for short to intermediate times.

  17. Bose-Einstein condensation in large time-averaged optical ring potentials

    NASA Astrophysics Data System (ADS)

    Bell, Thomas A.; Glidden, Jake A. P.; Humbert, Leif; Bromley, Michael W. J.; Haine, Simon A.; Davis, Matthew J.; Neely, Tyler W.; Baker, Mark A.; Rubinsztein-Dunlop, Halina

    2016-03-01

    Interferometric measurements with matter waves are established techniques for sensitive gravimetry, rotation sensing, and measurement of surface interactions, but compact interferometers will require techniques based on trapped geometries. In a step towards the realisation of matter wave interferometers in toroidal geometries, we produce a large, smooth ring trap for Bose-Einstein condensates using rapidly scanned time-averaged dipole potentials. The trap potential is smoothed by using the atom distribution as input to an optical intensity correction algorithm. Smooth rings with a diameter up to 300 μm are demonstrated. We experimentally observe and simulate the dispersion of condensed atoms in the resulting potential, with good agreement serving as an indication of trap smoothness. Under time of flight expansion we observe low energy excitations in the ring, which serves to constrain the lower frequency limit of the scanned potential technique. The resulting ring potential will have applications as a waveguide for atom interferometry and studies of superfluidity.

  18. The large-time behavior of the scalar, genuinely nonlinear Lax-Friedrichs scheme

    NASA Technical Reports Server (NTRS)

    Tadmor, E.

    1984-01-01

    The Lax-Friedrichs scheme, approximating the scalar, genuinely nonlinear conservation law u sub t + f sub x (u) = O where f(u) is, say, strictly double dot f dot a sub asterisk O is studied. The divided differences of the numerical solution at time t do not exceed 2 (t dot a sub asterisk) to the -1. This one-sided Lipschitz boundedness is in complete agreement with the corresponding estimate one has in the differential case; in particular, it is independent of the initial amplitude in sharp contrast to linear problems. It guarantees the entropy compactness of the scheme in this case, as well as providing a quantitative insight into the large-time behavior of the numerical computation.

  19. Modeling Optical Spectra of Large Organic Systems Using Real-Time Propagation of Semiempirical Effective Hamiltonians.

    PubMed

    Ghosh, Soumen; Andersen, Amity; Gagliardi, Laura; Cramer, Christopher J; Govind, Niranjan

    2017-09-12

    We present an implementation of a time-dependent semiempirical method (INDO/S) in NWChem using real-time (RT) propagation to address, in principle, the entire spectrum of valence electronic excitations. Adopting this model, we study the UV/vis spectra of medium-sized systems such as P3B2 and f-coronene, and in addition much larger systems such as ubiquitin in the gas phase and the betanin chromophore in the presence of two explicit solvents (water and methanol). RT-INDO/S provides qualitatively and often quantitatively accurate results when compared with RT- TDDFT or experimental spectra. Even though we only consider the INDO/S Hamiltonian in this work, our implementation provides a framework for performing electron dynamics in large systems using semiempirical Hartree-Fock Hamiltonians in general.

  20. Virtual Testing of Large Composite Structures: A Multiple Length/Time-Scale Framework

    NASA Astrophysics Data System (ADS)

    Gigliotti, Luigi; Pinho, Silvestre T.

    2015-12-01

    This paper illustrates a multiple length/time-scale framework for the virtual testing of large composite structures. Such framework hinges upon a Mesh Superposition Technique (MST) for the coupling between areas of the structure modelled at different length-scales and upon an efficient solid-to-shell numerical homogenization which exploits the internal symmetries of Unit Cells (UCs). Using this framework, it is possible to minimize the areas of the structure modelled at the lowest- (and computationally demanding) scales and the computational cost required to calculate the homogenised to be used in the higher-scales subdomains of multiscale FE models, as well as to simulate the mechanical response of different parts of the structure using different solvers, depending on where they are expected to provide the most computationally efficient solution. The relevance and key-aspects of the multiple length/time-scale framework are demonstrated through the analysis of a real-sized aeronautical composite component.

  1. The large-time behavior of the scalar, genuinely nonlinear Lax-Friedrichs scheme

    NASA Technical Reports Server (NTRS)

    Tadmor, E.

    1983-01-01

    The Lax-Friedrichs scheme, approximating the scalar, genuinely nonlinear conservation law u sub t + f sub x (u) = 0 where f(u) is, say, strictly convex double dot f dot a sub asterisk 0 is studied. The divided differences of the numerical solution at time t do not exceed 2 (t dot a sub asterisk) to the -1. This one-sided Lipschitz boundedness is in complete agreement with the corresponding estimate one has in the differential case; in particular, it is independent of the initial amplitude in sharp contrast to liner problems. It guarantees the entropy compactness of the scheme in this case, as well as providing a quantitive insight into the large-time behavior of the numerical computation.

  2. Large Eddy Simulation of an URBAN 2000 Experiment with Various Time-Dependent Forcing

    SciTech Connect

    Chan, S T; Leach, M J

    2004-06-15

    Under the sponsorship of the U.S. DOE and DHS, we have developed a Computational Fluid Dynamics (CFD) model for simulating airflow and dispersion of chemical/biological agents released in the urban environment. Our model, FEM3MP, is based on solving the three-dimensional, time-dependent, incompressible Navier-Stokes equations on massively parallel computer platforms. The numerical algorithm uses the finite element method for accurate representation of complex building shapes and variable terrain, together with a semi-implicit projection method and modern iterative solvers for efficient time integration (Gresho and Chan, 1998). Physical processes treated in our code include turbulence modeling via the RANS (Reynolds Averaged Navier-Stokes) and LES (Large Eddy Simulation) approaches, atmospheric stability, aerosols, UV radiation decay, surface energy budget, and vegetative canopies, etc.

  3. Travel Times for Screening Mammography: Impact of Geographic Expansion by a Large Academic Health System.

    PubMed

    Rosenkrantz, Andrew B; Liang, Yu; Duszak, Richard; Recht, Michael P

    2017-09-01

    This study aims to assess the impact of off-campus facility expansion by a large academic health system on patient travel times for screening mammography. Screening mammograms performed from 2013 to 2015 and associated patient demographics were identified using the NYU Langone Medical Center Enterprise Data Warehouse. During this time, the system's number of mammography facilities increased from 6 to 19, reflecting expansion beyond Manhattan throughout the New York metropolitan region. Geocoding software was used to estimate driving times from patients' homes to imaging facilities. For 147,566 screening mammograms, the mean estimated patient travel time was 19.9 ± 15.2 minutes. With facility expansion, travel times declined significantly (P < 0.001) from 26.8 ± 18.9 to 18.5 ± 13.3 minutes (non-Manhattan residents: from 31.4 ± 20.3 to 18.7 ± 13.6). This decline occurred consistently across subgroups of patient age, race, ethnicity, payer status, and rurality, leading to decreased variation in travel times between such subgroups. However, travel times to pre-expansion facilities remained stable (initial: 26.8 ± 18.9 minutes, final: 26.7 ± 18.6 minutes). Among women undergoing mammography before and after expansion, travel times were shorter for the postexpansion mammogram in only 6.3%, but this rate varied significantly (all P < 0.05) by certain demographic factors (higher in younger and non-Hispanic patients) and was as high as 18.2%-18.9% of patients residing in regions with the most active expansion. Health system mammography facility geographic expansion can improve average patient travel burden and reduce travel time variation among sociodemographic populations. Nonetheless, existing patients strongly tend to return to established facilities despite potentially shorter travel time locations, suggesting strong site loyalty. Variation in travel times likely relates to various factors other than facility proximity

  4. Precipitation-Snowmelt Timing and Snowmelt Augmentation of Large Peak Flow Events, Western Cascades, Oregon

    NASA Astrophysics Data System (ADS)

    Jennings, K. S.; Jones, J. A.

    2014-12-01

    Extreme rain-on-snow floods are known to result from snowmelt coincident with precipitation, but comparatively little is known about the relative timing of these factors within storm events. Cumulative net snowmelt (hourly, from a snowmelt lysimeter) was plotted against precipitation for 26 large storms (> 1-yr return period) over the period 1991-2012 in the transient snow zone of the H.J. Andrews Experimental Forest in the western Cascades of Oregon. The relative timing of precipitation and net snowmelt at the hourly time scale was assessed with wavelet coherence. Five precipitation-net snowmelt response categories were identified: flat; persistent melt; persistent snow accumulation; late melt; and late snow accumulation. Persistent melt events were characterized by increasing cumulative net snowmelt and precipitation and had the highest mean peak flow and water available for runoff. Both the persistent melt and persistent snow accumulation categories had large, contiguous regions of significant wavelet coherence at multiple temporal scales, but pulses of precipitation preceded pulses of snowmelt in the persistent melt events, whereas precipitation was absorbed by the snowpack in the persistent accumulation category. A dewpoint temperature consistently above 0.5°C, elevated wind speeds, and a high fraction of precipitation falling as rain in the persistent melt category facilitated rapid snowmelt rates. During the two extreme rain-on-snow events in the sample, snowmelt was significantly synchronized with precipitation at 1-h to 64-h time scales throughout the 10-day event duration. Event categorization and analysis of wavelet coherence between precipitation and snowmelt can help predict peak discharge magnitude.

  5. Large Scale GPS Processing at ESOC for LEO, GNSS and Real-Time Applications

    NASA Astrophysics Data System (ADS)

    Boomkamp, H.; Dow, J.

    2003-12-01

    Most POD systems that are used in GPS data analysis, for instance in routine IGS processing, are large FORTRAN programs that have evolved from early generation systems over many years of use. These systems do not exploit the advantages of modern software engineering technology, and their limited processing efficiency constrains their application to emerging large-scale GPS processes, like real-time GPS, high-rate data processing or combined solutions for LEO + MEO constellations. In support of such high-performance applications, the ESOC IGS Analysis Centre is developing a new POD system based on the latest software engineering methods. This system is optimised in its use of both CPU and memory, following fundamental rules of minimum information containment that are more commonly found in internet search engines or artificial intelligence applications. Although this new system still has an experimental status it is expected to augment the GPS data processing capacity at ESOC by at least one order of magnitude. Some innovative concepts behind the system will be presented, together with first examples of GPS processes that until now were prohibitively large or slow.

  6. Implementation Strategies for Large-Scale Transport Simulations Using Time Domain Particle Tracking

    NASA Astrophysics Data System (ADS)

    Painter, S.; Cvetkovic, V.; Mancillas, J.; Selroos, J.

    2008-12-01

    Time domain particle tracking is an emerging alternative to the conventional random walk particle tracking algorithm. With time domain particle tracking, particles are moved from node to node on one-dimensional pathways defined by streamlines of the groundwater flow field or by discrete subsurface features. The time to complete each deterministic segment is sampled from residence time distributions that include the effects of advection, longitudinal dispersion, a variety of kinetically controlled retention (sorption) processes, linear transformation, and temporal changes in groundwater velocities and sorption parameters. The simulation results in a set of arrival times at a monitoring location that can be post-processed with a kernel method to construct mass discharge (breakthrough) versus time. Implementation strategies differ for discrete flow (fractured media) systems and continuous porous media systems. The implementation strategy also depends on the scale at which hydraulic property heterogeneity is represented in the supporting flow model. For flow models that explicitly represent discrete features (e.g., discrete fracture networks), the sampling of residence times along segments is conceptually straightforward. For continuous porous media, such sampling needs to be related to the Lagrangian velocity field. Analytical or semi-analytical methods may be used to approximate the Lagrangian segment velocity distributions in aquifers with low-to-moderate variability, thereby capturing transport effects of subgrid velocity variability. If variability in hydraulic properties is large, however, Lagrangian velocity distributions are difficult to characterize and numerical simulations are required; in particular, numerical simulations are likely to be required for estimating the velocity integral scale as a basis for advective segment distributions. Aquifers with evolving heterogeneity scales present additional challenges. Large-scale simulations of radionuclide

  7. Robust linear equation dwell time model compatible with large scale discrete surface error matrix.

    PubMed

    Dong, Zhichao; Cheng, Haobo; Tam, Hon-Yuen

    2015-04-01

    The linear equation dwell time model can translate the 2D convolution process of material removal during subaperture polishing into a more intuitional expression, and may provide relatively fast and reliable results. However, the accurate solution of this ill-posed equation is not so easy, and its practicability for a large scale surface error matrix is still limited. This study first solves this ill-posed equation by Tikhonov regularization and the least square QR decomposition (LSQR) method, and automatically determines an optional interval and a typical value for the damped factor of regularization, which are dependent on the peak removal rate of tool influence functions. Then, a constrained LSQR method is presented to increase the robustness of the damped factor, which can provide more consistent dwell time maps than traditional LSQR. Finally, a matrix segmentation and stitching method is used to cope with large scale surface error matrices. Using these proposed methods, the linear equation model becomes more reliable and efficient in practical engineering.

  8. Asymptotics for Large Time of Global Solutions to the Generalized Kadomtsev-Petviashvili Equation

    NASA Astrophysics Data System (ADS)

    Hayashi, Nakao; Naumkin, Pavel I.; Saut, Jean-Claude

    We study the large time asymptotic behavior of solutions to the generalized Kadomtsev-Petviashvili (KP) equations where σ= 1 or σ=- 1. When ρ= 2 and σ=- 1, (KP) is known as the KPI equation, while ρ= 2, σ=+ 1 corresponds to the KPII equation. The KP equation models the propagation along the x-axis of nonlinear dispersive long waves on the surface of a fluid, when the variation along the y-axis proceeds slowly [10]. The case ρ= 3, σ=- 1 has been found in the modeling of sound waves in antiferromagnetics [15]. We prove that if ρ>= 3 is an integer and the initial data are sufficiently small, then the solution u of (KP) satisfies the following estimates: for all t∈R, where κ= 1 if ρ= 3 and κ= 0 if ρ>= 4. We also find the large time asymptotics for the solution.

  9. Research on resistance characteristics of YBCO tape under short-time DC large current impact

    NASA Astrophysics Data System (ADS)

    Zhang, Zhifeng; Yang, Jiabin; Qiu, Qingquan; Zhang, Guomin; Lin, Liangzhen

    2017-06-01

    Research of the resistance characteristics of YBCO tape under short-time DC large current impact is the foundation of the developing DC superconducting fault current limiter (SFCL) for voltage source converter-based high voltage direct current system (VSC-HVDC), which is one of the valid approaches to solve the problems of renewable energy integration. SFCL can limit DC short-circuit and enhance the interrupting capabilities of DC circuit breakers. In this paper, under short-time DC large current impacts, the resistance features of naked tape of YBCO tape are studied to find the resistance - temperature change rule and the maximum impact current. The influence of insulation for the resistance - temperature characteristics of YBCO tape is studied by comparison tests with naked tape and insulating tape in 77 K. The influence of operating temperature on the tape is also studied under subcooled liquid nitrogen condition. For the current impact security of YBCO tape, the critical current degradation and top temperature are analyzed and worked as judgment standards. The testing results is helpful for in developing SFCL in VSC-HVDC.

  10. Estimates for the Large Time Behavior of the Landau Equation in the Coulomb Case

    NASA Astrophysics Data System (ADS)

    Carrapatoso, Kleber; Desvillettes, Laurent; He, Lingbing

    2017-05-01

    This work deals with the large time behaviour of the spatially homogeneous Landau equation with Coulomb potential. Firstly, we obtain a bound from below of the entropy dissipation D( f) by weighted relative Fisher information of f with respect to the associated Maxwellian distribution, which leads to a variant of Cercignani's conjecture thanks to a logarithmic Sobolev inequality. Secondly, we prove the propagation of polynomial and stretched exponential moments with an at-most linearly growing in-time rate. As an application of these estimates, we show the convergence of any ( H- or weak) solution to the Landau equation with Coulomb potential to the associated Maxwellian equilibrium with an explicitly computable rate, assuming initial data with finite mass, energy, entropy and some higher L 1-moment. More precisely, if the initial data have some (large enough) polynomial L 1-moment, then we obtain an algebraic decay. If the initial data have a stretched exponential L 1-moment, then we recover a stretched exponential decay.

  11. A study of residence time distribution using radiotracer technique in the large scale plant facility

    NASA Astrophysics Data System (ADS)

    Wetchagarun, S.; Tippayakul, C.; Petchrak, A.; Sukrod, K.; Khoonkamjorn, P.

    2017-06-01

    As the demand for troubleshooting of large industrial plants increases, radiotracer techniques, which have capability to provide fast, online and effective detections to plant problems, have been continually developed. One of the good potential applications of the radiotracer for troubleshooting in a process plant is the analysis of Residence Time Distribution (RTD). In this paper, the study of RTD in a large scale plant facility using radiotracer technique was presented. The objective of this work is to gain experience on the RTD analysis using radiotracer technique in a “larger than laboratory” scale plant setup which can be comparable to the real industrial application. The experiment was carried out at the sedimentation tank in the water treatment facility of Thailand Institute of Nuclear Technology (Public Organization). Br-82 was selected to use in this work due to its chemical property, its suitable half-life and its on-site availability. NH4Br in the form of aqueous solution was injected into the system as the radiotracer. Six NaI detectors were placed along the pipelines and at the tank in order to determine the RTD of the system. The RTD and the Mean Residence Time (MRT) of the tank was analysed and calculated from the measured data. The experience and knowledge attained from this study is important for extending this technique to be applied to industrial facilities in the future.

  12. Deformation microstructures and timing of a large submarine landslide drilled offshore Martinique (IODP Exp. 340)

    NASA Astrophysics Data System (ADS)

    Guyard, H.; Le Friant, A.; Brunet, M.; Boudon, G.; Emmanuel, L.; Caron, B.; Villemant, B.; Feuillet, N.

    2015-12-01

    Flank-instabilities constitute a recurrent process in the long-term evolution of many volcanoes. A very large submarine landslide deposit (~2100 km2, ~300 km3) drilled southwest Martinique island during the IODP Exp. 340 in 2012 is likely associated with one (or more) major volcanic flank collapse of Mount Pelée during the Late Pleistocene. A recent study revealed that this D1/D2 deposit is emergent in its central part, frontally confined, and mainly comprises remobilized seafloor sediments rather than debris avalanche material from the volcanic edifice (Brunet et al., subm). Here, we investigate the sedimentary microstructures and timing of deformation from the central (Hole 1400B, ~37 km from the coastline) and distal (Hole 1399A, ~70 km from the coastline) units of the D1/D2 deposit, in order to better understand the emplacement dynamics of such potentially tsunamigenic submarine landslides. High resolution CT-Scan analyses were continuously performed on more than 300 m of sediment cores, in order to characterize and distinguish the internal architecture and the complex deformation features of the sediments at each drilling site. The establishment of the stratigraphy, based on δ18O measurements and AMS 14C dating, is still in progress and may confirm the possible link between the submarine landslide deposits and the flank collapse scars observed on the subaerial part of Martinique. These new insights into the timing and emplacement processes of this large submarine landslide will have important implications for tsunami hazards. ReferenceBrunet, M., Le Friant, A., Boudon, G., Lafuerza, S., Talling, P., Hornbach, M., Lebas, E., Guyard, H., and IODP Expedition 340 science party, submitted. Composition, geometry and emplacement dynamics of a large volcanic island landslide offshore Martinique: from volcano flank-collapse to seafloor sediment failure? Geochemistry, Geophysics, Geosystems.

  13. Characterization of Caramel Colour IV.

    PubMed

    Licht, B H; Shaw, K; Smith, C; Mendoza, M; Orr, J; Myers, D V

    1992-05-01

    A large number of commercial Caramel Colour IV samples were characterized in order to assess the uniformity of the class and to provide data to be used in specifications development. Owing to the chemical and physical complexity of caramel colour it was not feasible to perform detailed analysis of all constituents for assessment of uniformity. Instead, selected parameters were evaluated and judgements were made with respect to compositional uniformity based on the similarities of these parameters among the various samples. As Caramel Colour IV is required by the food industry in a range of colour intensities, there must be a range of properties that differ from sample to sample, but that are sufficiently similar for the material to still be considered as part of the Caramel Colour IV class. Fractions as well as whole caramel were analysed using selected spectrophotometric, chromatographic and chemical techniques. Samples were fractionated based on molecular weight and polarity. The data presented here provide evidence for the uniformity in composition of Caramel Colour IV with respect to molecular weight distribution, to nitrogen and sulphur content and their distribution throughout the fractions, to absorbance properties and to specific low molecular weight compounds. Thus, it can be concluded that Caramel Colour IV exhibits compositional uniformity within the range of colour intensity required by the food industry worldwide.

  14. On large time step TVD scheme for hyperbolic conservation laws and its efficiency evaluation

    NASA Astrophysics Data System (ADS)

    Qian, ZhanSen; Lee, Chun-Hian

    2012-08-01

    A large time step (LTS) TVD scheme originally proposed by Harten is modified and further developed in the present paper and applied to Euler equations in multidimensional problems. By firstly revealing the drawbacks of Harten's original LTS TVD scheme, and reasoning the occurrence of the spurious oscillations, a modified formulation of its characteristic transformation is proposed and a high resolution, strongly robust LTS TVD scheme is formulated. The modified scheme is proven to be capable of taking larger number of time steps than the original one. Following the modified strategy, the LTS TVD schemes for Yee's upwind TVD scheme and Yee-Roe-Davis's symmetric TVD scheme are constructed. The family of the LTS schemes is then extended to multidimensional by time splitting procedure, and the associated boundary condition treatment suitable for the LTS scheme is also imposed. The numerical experiments on Sod's shock tube problem, inviscid flows over NACA0012 airfoil and ONERA M6 wing are performed to validate the developed schemes. Computational efficiencies for the respective schemes under different CFL numbers are also evaluated and compared. The results reveal that the improvement is sizable as compared to the respective single time step schemes, especially for the CFL number ranging from 1.0 to 4.0.

  15. Real time identification of large space structures. Ph.D. Thesis - MIT

    NASA Technical Reports Server (NTRS)

    Voss, Janice E.

    1987-01-01

    Identification of frequencies, damping ratios, and mode shapes of large space structures (LSSs) are examined in real time. Real time processing allows for quick updates of model processing after a reconfiguration of structural failure. Recursive lattice least squares (RLLS) was selected as the baseline algorithm for the identification. Simulation results on a one dimensional LSS demonstrated that it provides good estimates, was not ill-conditioned in the presence of under-excited modes, allowed activity by a supervisory control system which prevented damage to the LSS or excessive drift, and was capable of real-time processing for typical LSS models. A suboptimal version of RLLS, which is equivalent to simulated parallel processing, was derived. A NASTRAN model of the dual keel U.S. space station was used to demonstrate the input/identification algorithm package in a more realistic simulation. Because the first eight flexible modes were very close together, the identification was much more difficult than in the simple examples. Even so, the model was accurately identified in real time.

  16. Piloted simulator study of allowable time delays in large-airplane response

    NASA Technical Reports Server (NTRS)

    Grantham, William D.; Bert T.?aetingas, Stephen A.dings with ran; Bert T.?aetingas, Stephen A.dings with ran

    1987-01-01

    A piloted simulation was performed to determine the permissible time delay and phase shift in the flight control system of a specific large transport-type airplane. The study was conducted with a six degree of freedom ground-based simulator and a math model similar to an advanced wide-body jet transport. Time delays in discrete and lagged form were incorporated into the longitudinal, lateral, and directional control systems of the airplane. Three experienced pilots flew simulated approaches and landings with random localizer and glide slope offsets during instrument tracking as their principal evaluation task. Results of the present study suggest a level 1 (satisfactory) handling qualities limit for the effective time delay of 0.15 sec in both the pitch and roll axes, as opposed to a 0.10-sec limit of the present specification (MIL-F-8785C) for both axes. Also, the present results suggest a level 2 (acceptable but unsatisfactory) handling qualities limit for an effective time delay of 0.82 sec and 0.57 sec for the pitch and roll axes, respectively, as opposed to 0.20 sec of the present specifications for both axes. In the area of phase shift between cockpit input and control surface deflection,the results of this study, flown in turbulent air, suggest less severe phase shift limitations for the approach and landing task-approximately 50 deg. in pitch and 40 deg. in roll - as opposed to 15 deg. of the present specifications for both axes.

  17. Associations between motor timing, music practice, and intelligence studied in a large sample of twins.

    PubMed

    Ullén, Fredrik; Mosing, Miriam A; Madison, Guy

    2015-03-01

    Music performance depends critically on precise processing of time. A common model behavior in studies of motor timing is isochronous serial interval production (ISIP), that is, hand/finger movements with a regular beat. ISIP accuracy is related to both music practice and intelligence. Here we present a study of these associations in a large twin cohort, demonstrating that the effects of music practice and intelligence on motor timing are additive, with no significant multiplicative (interaction) effect. Furthermore, the association between music practice and motor timing was analyzed with the use of a co-twin control design using intrapair differences. These analyses revealed that the phenotypic association disappeared when all genetic and common environmental factors were controlled. This suggests that the observed association may not reflect a causal effect of music practice on ISIP performance but rather reflect common influences (e.g., genetic effects) on both outcomes. The relevance of these findings for models of practice and expert performance is discussed. © 2014 New York Academy of Sciences.

  18. Mechanical properties of bulk polydimethylsiloxane for microfluidics over a large range of frequencies and aging times

    NASA Astrophysics Data System (ADS)

    Placet, V.; Delobelle, P.

    2015-03-01

    The dynamic mechanical characterization of polydimethylsiloxane (PDMS) over a large range of frequencies (10-2 < f < 105 Hz) and long aging times at room temperature (4 h < tv < ~60 000 h) has been presented. Three samples with different curing conditions have been studied and three different techniques, dynamic mechanical analysis at different temperatures, nano-indentation and scanning micro-deformation microscopy, have been used. Although the three techniques work at different scales and at different frequencies all the results match the same master curve. As expected, the storage and the loss moduli greatly increase with the frequency. Moreover, these moduli moderately increase with the aging time tv depending on the curing temperature. A simple model which takes the frequency and the aging time into account, and which is based on the Havriliak-Negami model, has been presented and identified. Hence, values of the relaxed and instantaneous moduli at tv = 0 and tv = ∞ are proposed. Only the relaxed moduli depend on the curing conditions and moreover it has been shown that the tangent of the phase lag is independent of the aging time and thus of the curing process.

  19. Time-to-treatment of diffuse large B-cell lymphoma in São Paulo

    PubMed Central

    Xavier, Flávia Dias; Levy, Debora; Pereira, Juliana

    2014-01-01

    OBJECTIVE: Diffuse large B-cell lymphoma is the most common type of non-Hodgkin lymphoma, accounting for nearly 50% of the cases in the Hematology Department of the Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo and Instituto do Câncer do Estado de São Paulo. The treatment outcome is influenced by age, abnormal lactate dehydrogenase levels, extranodal infiltration, the disease stage and the patient's performance status. In this study, we sought to report the time-to-treatment of diffuse large B-cell lymphoma in São Paulo's public health system network and its impact on patient outcomes. METHODS: We prospectively followed a cohort of 42 consecutive patients with de novo diffuse large B-cell lymphoma between 2008 and 2012. RESULTS: Our patients had more advanced disease than that reported in the literature (61.9% vs. 46%). In São Paulo's public health system network, it took an average of 7.4 months for a diagnosis to be made and an additional 1.4 months to obtain an appointment with a specialist. Once at our Hematology Department, it took less than 20 days for staging, confirmation of the diagnosis and treatment initiation. An interval from signs or symptoms to treatment of more than 6 months was associated with inferior progression-free survival in 3 years (p = 0.049). CONCLUSION: A delay in the diagnosis of diffuse large B-cell lymphoma is a public health problem and may be associated with worse progression-free survival. PMID:24838904

  20. Backward-in-time methods to simulate large-scale transport and mixing in the ocean

    NASA Astrophysics Data System (ADS)

    Prants, S. V.

    2015-06-01

    In oceanography and meteorology, it is important to know not only where water or air masses are headed for, but also where they came from as well. For example, it is important to find unknown sources of oil spills in the ocean and of dangerous substance plumes in the atmosphere. It is impossible with the help of conventional ocean and atmospheric numerical circulation models to extrapolate backward from the observed plumes to find the source because those models cannot be reversed in time. We review here recently elaborated backward-in-time numerical methods to identify and study mesoscale eddies in the ocean and to compute where those waters came from to a given area. The area under study is populated with a large number of artificial tracers that are advected backward in time in a given velocity field that is supposed to be known analytically or numerically, or from satellite and radar measurements. After integrating advection equations, one gets positions of each tracer on a fixed day in the past and can identify from known destinations a particle positions at earlier times. The results provided show that the method is efficient, for example, in estimating probabilities to find increased concentrations of radionuclides and other pollutants in oceanic mesoscale eddies. The backward-in-time methods are illustrated in this paper with a few examples. Backward-in-time Lagrangian maps are applied to identify eddies in satellite-derived and numerically generated velocity fields and to document the pathways by which they exchange water with their surroundings. Backward-in-time trapping maps are used to identify mesoscale eddies in the altimetric velocity field with a risk to be contaminated by Fukushima-derived radionuclides. The results of simulations are compared with in situ mesurement of caesium concentration in sea water samples collected in a recent research vessel cruise in the area to the east of Japan. Backward-in-time latitudinal maps and the corresponding

  1. Time-Staged Gamma Knife Stereotactic Radiosurgery for Large Cerebral Arteriovenous Malformations: A Preliminary Report

    PubMed Central

    Park, Hye Ran; Lee, Jae Meen; Kim, Jin Wook; Han, Jung-Ho; Chung, Hyun-Tai; Han, Moon Hee; Kim, Dong Gyu; Paek, Sun Ha

    2016-01-01

    Objective We retrospectively analyzed our experience with time-staged gamma knife stereotactic radiosurgery (GKS) in treating large arteriovenous malformation(AVM)s;≥ 10 cm3). Methods Forty-five patients who underwent time-staged GKS (2-stage, n = 37;3-stage,n = 8) between March 1998 and December 2011 were included. The mean volume treated was 20.42±6.29 cm3 (range, 10.20–38.50 cm3). Obliteration rates of AVMs and the associated complications after GKS were evaluated. Results Mean AVM volume (and median marginal dose) at each GKS session in the 37 patients who underwent 2-stage GKS was 19.67±6.08 cm3 (13 Gy) at session 1 and 6.97±6.92 cm3 (17 Gy) at session 2. The median interval period was 39 months. After follow-up period of 37 months, the complete obliteration rate was 64.9%. The mean AVM volume (and median marginal dose) at each GKS session in the 8 patients who underwent 3-stage GKS was 23.90±6.50 cm3 (12.25 Gy), 19.43±7.46 cm3 (13.5 Gy), 7.48±6.86 cm3 (15.5 Gy) at session 1, 2, and 3, respectively. The median interval duration between each GKS session was 37.5 and 38 months, respectively. After a median follow-up period of 47.5 months, 5 patients (62.5%) achieved complete obliteration. Postradiosurgical hemorrhage developed in 5 patients (11.1%) including one case of major bleeding and 4 cases of minor bleeding. No patient suffered from clinically symptomatic radiation necrosis following radiation. Conclusion Time-staged GKS could be an effective and safe treatment option in the management of large AVMs. PMID:27806123

  2. Stage IV work hardening in cubic metals

    SciTech Connect

    Rollett, A.D.; Kocks, U.F.; Doherty, R.D.

    1986-01-01

    The work hardening of fcc metals at large strains is discussed with reference to the linear stress-strain behavior often observed at large strains and known as Stage IV. The experimental evidence shows that Stage IV is a work hardening phenomenon that is found quite generally, even in pure fcc metals subjected to homogeneous deformation. A simple model for Stage IV in pure metals is presented, based on the accumulation of dislocation debris. Experiments are described for large strain torsion tests on four aluminum alloys. The level and extent of Stage IV scaled with the saturation stress that would represent the end of Stage III in the absence of a Stage IV. Reversing the torsion after large prestrains produced transient reductions in the work hardening. The strain rate sensitivity was also measured before and during the transient and found not to vary significantly. The microstructure observed at large strains in an Mg alloy suggest that Stage IV can occur in the absence of microband formation. Previous proposals for the cause of Stage IV are reviewed and found to be not supported by recent experimental data.

  3. Quadratic Time-Frequency Analysis of Hydroacoustic Signals as Applied to Acoustic Emissions of Large Whales

    NASA Astrophysics Data System (ADS)

    Le Bras, Ronan; Victor, Sucic; Damir, Malnar; Götz, Bokelmann

    2014-05-01

    In order to enrich the set of attributes in setting up a large database of whale signals, as envisioned in the Baleakanta project, we investigate methods of time-frequency analysis. The purpose of establishing the database is to increase and refine knowledge of the emitted signal and of its propagation characteristics, leading to a better understanding of the animal migrations in a non-invasive manner and to characterize acoustic propagation in oceanic media. The higher resolution for signal extraction and a better separation from other signals and noise will be used for various purposes, including improved signal detection and individual animal identification. The quadratic class of time-frequency distributions (TFDs) is the most popular set of time-frequency tools for analysis and processing of non-stationary signals. Two best known and most studied members of this class are the spectrogram and the Wigner-Ville distribution. However, to be used efficiently, i.e. to have highly concentrated signal components while significantly suppressing interference and noise simultaneously, TFDs need to be optimized first. The optimization method used in this paper is based on the Cross-Wigner-Ville distribution, and unlike similar approaches it does not require prior information on the analysed signal. The method is applied to whale signals, which, just like the majority of other real-life signals, can generally be classified as multicomponent non-stationary signals, and hence time-frequency techniques are a natural choice for their representation, analysis, and processing. We present processed data from a set containing hundreds of individual calls. The TFD optimization method results into a high resolution time-frequency representation of the signals. It allows for a simple extraction of signal components from the TFD's dominant ridges. The local peaks of those ridges can then be used for the signal components instantaneous frequency estimation, which in turn can be used as

  4. Shared control on lunar spacecraft teleoperation rendezvous operations with large time delay

    NASA Astrophysics Data System (ADS)

    Ya-kun, Zhang; Hai-yang, Li; Rui-xue, Huang; Jiang-hui, Liu

    2017-08-01

    Teleoperation could be used in space on-orbit serving missions, such as object deorbits, spacecraft approaches, and automatic rendezvous and docking back-up systems. Teleoperation rendezvous and docking in lunar orbit may encounter bottlenecks for the inherent time delay in the communication link and the limited measurement accuracy of sensors. Moreover, human intervention is unsuitable in view of the partial communication coverage problem. To solve these problems, a shared control strategy for teleoperation rendezvous and docking is detailed. The control authority in lunar orbital maneuvers that involves two spacecraft as rendezvous and docking in the final phase was discussed in this paper. The predictive display model based on the relative dynamic equations is established to overcome the influence of the large time delay in communication link. We discuss and attempt to prove via consistent, ground-based simulations the relative merits of fully autonomous control mode (i.e., onboard computer-based), fully manual control (i.e., human-driven at the ground station) and shared control mode. The simulation experiments were conducted on the nine-degrees-of-freedom teleoperation rendezvous and docking simulation platform. Simulation results indicated that the shared control methods can overcome the influence of time delay effects. In addition, the docking success probability of shared control method was enhanced compared with automatic and manual modes.

  5. Boreal Forests Sequester Large Amounts of Mercury over Millennial Time Scales in the Absence of Wildfire.

    PubMed

    Giesler, Reiner; Clemmensen, Karina E; Wardle, David A; Klaminder, Jonatan; Bindler, Richard

    2017-03-07

    Alterations in fire activity due to climate change and fire suppression may have profound effects on the balance between storage and release of carbon (C) and associated volatile elements. Stored soil mercury (Hg) is known to volatilize due to wildfires and this could substantially affect the land-air exchange of Hg; conversely the absence of fires and human disturbance may increase the time period over which Hg is sequestered. Here we show for a wildfire chronosequence spanning over more than 5000 years in boreal forest in northern Sweden that belowground inventories of total Hg are strongly related to soil humus C accumulation (R(2) = 0.94, p < 0.001). Our data clearly show that northern boreal forest soils have a strong sink capacity for Hg, and indicate that the sequestered Hg is bound in soil organic matter pools accumulating over millennia. Our results also suggest that more than half of the Hg stock in the sites with the longest time since fire originates from deposition predating the onset of large-scale anthropogenic emissions. This study emphasizes the importance of boreal forest humus soils for Hg storage and reveals that this pool is likely to persist over millennial time scales in the prolonged absence of fire.

  6. Real-time modulated nanoparticle separation with an ultra-large dynamic range.

    PubMed

    Zeming, Kerwin Kwek; Thakor, Nitish V; Zhang, Yong; Chen, Chia-Hung

    2016-01-07

    Nanoparticles exhibit size-dependent properties which make size-selective purification of proteins, DNA or synthetic nanoparticles essential for bio-analytics, clinical medicine, nano-plasmonics and nano-material sciences. Current purification methods of centrifugation, column chromatography and continuous-flow techniques suffer from particle aggregation, multi-stage process, complex setups and necessary nanofabrication. These increase process costs and time, reduce efficiency and limit dynamic range. Here, we achieve an unprecedented real-time nanoparticle separation (51-1500 nm) using a large-pore (2 μm) deterministic lateral displacement (DLD) device. No external force fields or nanofabrication are required. Instead, we investigated innate long-range electrostatic influences on nanoparticles within a fluid medium at different NaCl ionic concentrations. In this study we account for the electrostatic forces beyond Debye length and showed that they cannot be assumed as negligible especially for precise nanoparticle separation methods such as DLD. Our findings have enabled us to develop a model to simultaneously quantify and modulate the electrostatic force interactions between nanoparticle and micropore. By simply controlling buffer solutions, we achieve dynamic nanoparticle size separation on a single device with a rapid response time (<20 s) and an enlarged dynamic range (>1200%), outperforming standard benchtop centrifuge systems. This novel method and model combines device simplicity, isolation precision and dynamic flexibility, opening opportunities for high-throughput applications in nano-separation for industrial and biological applications.

  7. Time-domain hybrid method for simulating large amplitude motions of ships advancing in waves

    NASA Astrophysics Data System (ADS)

    Liu, Shukui; Papanikolaou, Apostolos D.

    2011-03-01

    Typical results obtained by a newly developed, nonlinear time domain hybrid method for simulating large amplitude motions of ships advancing with constant forward speed in waves are presented. The method is hybrid in the way of combining a time-domain transient Green function method and a Rankine source method. The present approach employs a simple double integration algorithm with respect to time to simulate the free-surface boundary condition. During the simulation, the diffraction and radiation forces are computed by pressure integration over the mean wetted surface, whereas the incident wave and hydrostatic restoring forces/moments are calculated on the instantaneously wetted surface of the hull. Typical numerical results of application of the method to the seakeeping performance of a standard containership, namely the ITTC S175, are herein presented. Comparisons have been made between the results from the present method, the frequency domain 3D panel method (NEWDRIFT) of NTUA-SDL and available experimental data and good agreement has been observed for all studied cases between the results of the present method and comparable other data.

  8. Adaptive sampling for real-time rendering of large terrain based on B-spline wavelet

    NASA Astrophysics Data System (ADS)

    Kalem, Sid Ali; Kourgli, Assia

    2017-05-01

    This paper describes a central processing unit (CPU)-based technique for terrain geometry rendering that could relieve graphics processing unit (GPU) from processing the appropriate level of detail (LOD) of the geometric surface. The proposed approach alleviates the computational load on the CPU and approaches GPU-based efficiency. As the datasets of realistic terrains are usually huge for real-time rendering, we suggest using a training stage to handle large tiled QuadTree terrain representation. The training stage is based on multiresolution wavelet decomposition and is used to limit the region of error control inside the tile. Maximum approximation errors are then calculated for each tile at different resolutions. Maximum world-space errors of the tile at different resolutions permit selection of the appropriate resolution of downsampling that will represent the tile at the run time. Tests and experiments demonstrate that B-spline 0 and B-spline 1 wavelets, well known for their properties of localization and their compact support, are suitable for fast and accurate localization of the maximum approximation error. The experimental results demonstrate that the proposed approach drastically reduces computation time in the CPU. Such a technique should also be used on low/medium end PCs, and embedded systems that are not equipped with the latest models of graphic hardware.

  9. Timing of occurrence of large submarine landslides on the Atlantic Ocean margin

    USGS Publications Warehouse

    Lee, H.J.

    2009-01-01

    Submarine landslides are distributed unevenly both in space and time. Spatially, they occur most commonly in fjords, active river deltas, submarine canyon-fan systems, the open continental slope and on the flanks of oceanic volcanic islands. Temporally, they are influenced by the size, location, and sedimentology of migrating depocenters, changes in seafloor pressures and temperatures, variations in seismicity and volcanic activity, and changes in groundwater flow conditions. The dominant factor influencing the timing of submarine landslide occurrence is glaciation. A review of known ages of submarine landslides along the margins of the Atlantic Ocean, augmented by a few ages from other submarine locations shows a relatively even distribution of large landslides with time from the last glacial maximum until about five thousand years after the end of glaciation. During the past 5000??yr, the frequency of occurrence is less by a factor of 1.7 to 3.5 than during or shortly after the last glacial/deglaciation period. Such an association likely exists because of the formation of thick deposits of sediment on the upper continental slope during glacial periods and increased seismicity caused by isostatic readjustment during and following deglaciation. Hydrate dissociation may play a role, as suggested previously in the literature, but the connection is unclear.

  10. Statistical analysis of error rate of large-scale single flux quantum logic circuit by considering fluctuation of timing parameters

    NASA Astrophysics Data System (ADS)

    Yamanashi, Yuki; Masubuchi, Kota; Yoshikawa, Nobuyuki

    2016-11-01

    The relationship between the timing margin and the error rate of the large-scale single flux quantum logic circuits is quantitatively investigated to establish a timing design guideline. We observed that the fluctuation in the set-up/hold time of single flux quantum logic gates caused by thermal noises is the most probable origin of the logical error of the large-scale single flux quantum circuit. The appropriate timing margin for stable operation of the large-scale logic circuit is discussed by taking the fluctuation of setup/hold time and the timing jitter in the single flux quantum circuits. As a case study, the dependence of the error rate of the 1-million-bit single flux quantum shift register on the timing margin is statistically analyzed. The result indicates that adjustment of timing margin and the bias voltage is important for stable operation of a large-scale SFQ logic circuit.

  11. Increased fluoroquinolone resistance with time in Escherichia coli from >17,000 patients at a large county hospital as a function of culture site, age, sex, and location

    PubMed Central

    Boyd, Lauren Becnel; Atmar, Robert L; Randall, Graham L; Hamill, Richard J; Steffen, David; Zechiedrich, Lynn

    2008-01-01

    Background Escherichia coli infections are common and often treated with fluoroquinolones. Fluoroquinolone resistance is of worldwide importance and is monitored by national and international surveillance networks. In this study, we analyzed the effects of time, culture site, and patient age, sex, and location on fluoroquinolone resistance in E. coli clinical isolates. Methods To understand how patient factors and time influenced fluoroquinolone resistance and to determine how well data from surveillance networks predict trends at Ben Taub General Hospital in Houston, TX, we used Perl to parse and MySQL to house data from antibiograms (n ≅ 21,000) for E. coli isolated between 1999 to 2004 using Chi Square, Bonferroni, and Multiple Linear Regression methods. Results Fluoroquinolone resistance (i) increased with time; (ii) exceeded national averages by 2- to 4-fold; (iii) was higher in males than females, largely because of urinary isolates from male outpatients; (iv) increased with patient age; (v) was 3% in pediatric patients; (vi) was higher in hospitalized patients than outpatients; (vii) was higher in sputum samples, particularly from inpatients, than all other culture sites, including blood and urine, regardless of patient location; and (viii) was lowest in genital isolates than all other culture sites. Additionally, the data suggest that, with regard to susceptibility or resistance by the Dade Behring MicroScan system, a single fluoroquinolone suffices as a "surrogate marker" for all of the fluoroquinolone tested. Conclusion Large surveillance programs often did not predict E. coli fluoroquinolone resistance trends at a large, urban hospital with a largely indigent, ethnically diverse patient population or its affiliated community clinics. PMID:18197977

  12. Lipschitz regularity for integro-differential equations with coercive Hamiltonians and application to large time behavior

    NASA Astrophysics Data System (ADS)

    Barles, Guy; Ley, Olivier; Topp, Erwin

    2017-02-01

    In this paper, we provide suitable adaptations of the ‘weak version of Bernstein method’ introduced by the first author in 1991, in order to obtain Lipschitz regularity results and Lipschitz estimates for nonlinear integro-differential elliptic and parabolic equations set in the whole space. Our interest is to obtain such Lipschitz results to possibly degenerate equations, or to equations which are indeed ‘uniformly elliptic’ (maybe in the nonlocal sense) but which do not satisfy the usual ‘growth condition’ on the gradient term allowing to use (for example) the Ishii-Lions’ method. We treat the case of a model equation with a superlinear coercivity on the gradient term which has a leading role in the equation. This regularity result together with comparison principle provided for the problem allow to obtain the ergodic large time behavior of the evolution problem in the periodic setting.

  13. Using tablets for real-time formative assessment in large-enrollment introductory courses

    NASA Astrophysics Data System (ADS)

    Ruskell, Todd

    2013-04-01

    Many large-enrollment introductory physics courses now use personal response devices (clickers) to engage students during class and collect data for real-time formative assessment. However, most systems only allow for multiple-choice or in some cases numeric or simple text answers. A program called inkSurvey allows faculty to ask more open-ended questions and students can submit both text and graphical responses from tablet computers. This provides faculty much greater insight into a student's problem-solving process. In our pilot project standard clickers were used in the first half of a calculus-based physics I course, and in the second half of the semester, tablets and inkSurvey were used to collect formative assessment data. We will report on initial impressions of both the faculty and students regarding the relative utility and effectiveness of each tool.

  14. Critical Keller-Segel meets Burgers on {{{S}}^{1}} : large-time smooth solutions

    NASA Astrophysics Data System (ADS)

    Burczak, Jan; Granero-Belinchón, Rafael

    2016-12-01

    We show that solutions to the parabolic-elliptic Keller-Segel system on {{{S}}1} with critical fractional diffusion (- Δ ){{}\\frac{1{2}}} remain smooth for any initial data and any positive time. This disproves, at least in the periodic setting, the large-data-blowup conjecture by Bournaveas and Calvez [15]. As a tool, we show smoothness of solutions to a modified critical Burgers equation via a generalization of the ingenious method of moduli of continuity by Kiselev, Nazarov and Shterenberg [35] over a setting where the considered equation has no scaling. This auxiliary result may be interesting by itself. Finally, we study the asymptotic behavior of global solutions corresponding to small initial data, improving the existing results.

  15. Time-space Kriging to address the spatiotemporal misalignment in the large datasets.

    PubMed

    Liang, Dong; Kumar, Naresh

    2013-06-01

    This paper presents a Bayesian hierarchical spatiotemporal method of interpolation, termed as Markov Cube Kriging (MCK). The classical Kriging methods become computationally prohibitive, especially for large datasets due to the O(n(3)) matrix decomposition. MCK offers novel and computationally efficient solutions to address spatiotemporal misalignment, mismatch in the spatiotemporal scales and missing values across space and time in large spatiotemporal datasets. MCK is flexible in that it allows for non-separable spatiotemporal structure and nonstationary covariance at the hierarchical spatiotemporal scales. Employing MCK we developed estimates of daily concentration of fine particulates matter ≤2.5 μm in aerodynamic diameter (PM2.5) at 2.5 km spatial grid for the Cleveland Metropolitan Statistical Area, 2000 to 2009. Our validation and cross-validation suggest that MCK achieved robust prediction of spatiotemporal random effects and underlying hierarchical and nonstationary spatiotemporal structure in air pollution data. MCK has important implications for environmental epidemiology and environmental sciences for exposure quantification and collocation of data from different sources, available at different spatiotemporal scales.

  16. Time-space Kriging to address the spatiotemporal misalignment in the large datasets

    PubMed Central

    Liang, Dong; Kumar, Naresh

    2013-01-01

    This paper presents a Bayesian hierarchical spatiotemporal method of interpolation, termed as Markov Cube Kriging (MCK). The classical Kriging methods become computationally prohibitive, especially for large datasets due to the O(n3) matrix decomposition. MCK offers novel and computationally efficient solutions to address spatiotemporal misalignment, mismatch in the spatiotemporal scales and missing values across space and time in large spatiotemporal datasets. MCK is flexible in that it allows for non-separable spatiotemporal structure and nonstationary covariance at the hierarchical spatiotemporal scales. Employing MCK we developed estimates of daily concentration of fine particulates matter ≤2.5 μm in aerodynamic diameter (PM2.5) at 2.5 km spatial grid for the Cleveland Metropolitan Statistical Area, 2000 to 2009. Our validation and cross-validation suggest that MCK achieved robust prediction of spatiotemporal random effects and underlying hierarchical and nonstationary spatiotemporal structure in air pollution data. MCK has important implications for environmental epidemiology and environmental sciences for exposure quantification and collocation of data from different sources, available at different spatiotemporal scales. PMID:24039539

  17. Real-time holographic compensation of large optics for deployment in space

    NASA Astrophysics Data System (ADS)

    Guthals, Dennis M.; Sox, Daniel; Joswick, Michael D.; Rodney, Paul J.

    2000-11-01

    Large deployable space-based optical systems will likely require complex structure position controls in conjunction with an adaptive optic to maintain optical tolerances necessary for near diffraction-limited performance. A real- time holographic (RTH) compensation system can greatly reduce the requirements and complexity of the position control system and enable the use of novel or imperfect optical components for large mirror surfaces. A hologram of the distorted primary is recorded with a local beacon at 532 nm (approximately 100 nJ/exposure) on an optically addressed spatial light modulator and transferred as a phase grating to a ferroelectric liquid crystal layer. The hologram is played back with target light containing the same optical distortion. A corrected image is obtained in the conjugate diffracted order where the phase of the optical distortion is subtracted from the distorted image. We report recent test results and analysis of a RTH- compensated deformed mirror of 0.75 m diameter. The short exposure hologram is recorded at video frequencies (30 Hz) at bandwidths up to 5 kHz. Correction for tens of waves of static and dynamic optical distortions including mechanical and thermal warp, mechanical vibration, and air turbulence are shown for monochromatic (532 nm) and broadband (532 +/- 40 nm) illuminated targets. We also report on the generation of blazed gratings in electrically addressed spatial light modulators to achieve greatly enhanced diffraction efficiencies and to perform beam steering.

  18. Detrending Algorithms in Large Time Series: Application to TFRM-PSES Data

    NASA Astrophysics Data System (ADS)

    del Ser, D.; Fors, O.; Núñez, J.; Voss, H.; Rosich, A.; Kouprianov, V.

    2015-07-01

    Certain instrumental effects and data reduction anomalies introduce systematic errors in photometric time series. Detrending algorithms such as the Trend Filtering Algorithm (TFA; Kovács et al. 2004) have played a key role in minimizing the effects caused by these systematics. Here we present the results obtained after applying the TFA, Savitzky & Golay (1964) detrending algorithms, and the Box Least Square phase-folding algorithm (Kovács et al. 2002) to the TFRM-PSES data (Fors et al. 2013). Tests performed on these data show that by applying these two filtering methods together the photometric RMS is on average improved by a factor of 3-4, with better efficiency towards brighter magnitudes, while applying TFA alone yields an improvement of a factor 1-2. As a result of this improvement, we are able to detect and analyze a large number of stars per TFRM-PSES field which present some kind of variability. Also, after porting these algorithms to Python and parallelizing them, we have improved, even for large data samples, the computational performance of the overall detrending+BLS algorithm by a factor of ˜10 with respect to Kovács et al. (2004).

  19. Trench parallel anisotropy and large delay times: Elasticity and anisotropy of antigorite at high pressures

    NASA Astrophysics Data System (ADS)

    Mookherjee, Mainak; Capitani, Gian Carlo

    2011-05-01

    Using theoretical methods, we calculate the full elastic constant tensor and equation of state of antigorite up to 10 GPa, a pressure range that encompasses its experimentally observed stability field. At ambient conditions, the elastic constant tensor reveals significantly large acoustic anisotropy (38% in VP; 35% in VS) compared to the dominant mantle phase olivine. The shear anisotropy is enhanced upon compression. Upon compression, the full elastic constant tensor reveals anomaly at ρ ˜ 2.69 gm cm-3. At ρ < 2.69 gm cm-3, we find that the pressure-volume results for antigorite are well represented by a third order Birch-Murnaghan formulation, with K0 = 52 GPa, K0‧ = 8.5 and V0 = 3037 Å3 (ρ0 ˜ 2.48 gm cm-3). Our results on elasticity and anisotropy at conditions relevant to the mantle wedge indicates that a 10-20 km layer of antigorite might account for the observed shear polarization anisotropy with fast polarization parallel to the trench and associated large delay times of 1-2 sec observed in some subduction zone settings.

  20. Time-spectral characteristics of large-scale cloud systems in the tropical Pacific.

    NASA Technical Reports Server (NTRS)

    Sikdar, D. N.; Young, J. A.; Suomi, V. E.

    1972-01-01

    Study of time series of areal cloud coverage over the central Pacific to determine the large-scale variations of tropical disturbance activity for a four-month period in 1967. The persistent and fluctuating components are found to be more prevalent in regions of high and low mean cloudiness, respectively, with major longitudinal variations in activity most evident in the Southern Hemisphere. Normalized power spectra show that the transient activity occurring in the equatorial zone is dominated by shorter periods of about four days, while longer periods are dominant away from the equator. Coherency magnitudes and phases between different locations indicate that propagating cloud systems are most identifiable at lower frequencies in the Southern Hemisphere, and at somewhat higher frequencies in the Northern Hemisphere. Activity with periods in excess of five days consists largely of both westward and eastward propagation on the planetary wave scale. The shorter periods appear to consist of both synoptic-scale and planetary-scale modes, with westward propagation dominant near the equator.

  1. Spatial, temporal, and hybrid decompositions for large-scale vehicle routing with time windows

    SciTech Connect

    Bent, Russell W

    2010-01-01

    This paper studies the use of decomposition techniques to quickly find high-quality solutions to large-scale vehicle routing problems with time windows. It considers an adaptive decomposition scheme which iteratively decouples a routing problem based on the current solution. Earlier work considered vehicle-based decompositions that partitions the vehicles across the subproblems. The subproblems can then be optimized independently and merged easily. This paper argues that vehicle-based decompositions, although very effective on various problem classes also have limitations. In particular, they do not accommodate temporal decompositions and may produce spatial decompositions that are not focused enough. This paper then proposes customer-based decompositions which generalize vehicle-based decouplings and allows for focused spatial and temporal decompositions. Experimental results on class R2 of the extended Solomon benchmarks demonstrates the benefits of the customer-based adaptive decomposition scheme and its spatial, temporal, and hybrid instantiations. In particular, they show that customer-based decompositions bring significant benefits over large neighborhood search in contrast to vehicle-based decompositions.

  2. Efficient Constant-Time Complexity Algorithm for Stochastic Simulation of Large Reaction Networks.

    PubMed

    Thanh, Vo Hong; Zunino, Roberto; Priami, Corrado

    2017-01-01

    Exact stochastic simulation is an indispensable tool for a quantitative study of biochemical reaction networks. The simulation realizes the time evolution of the model by randomly choosing a reaction to fire and update the system state according to a probability that is proportional to the reaction propensity. Two computationally expensive tasks in simulating large biochemical networks are the selection of next reaction firings and the update of reaction propensities due to state changes. We present in this work a new exact algorithm to optimize both of these simulation bottlenecks. Our algorithm employs the composition-rejection on the propensity bounds of reactions to select the next reaction firing. The selection of next reaction firings is independent of the number reactions while the update of propensities is skipped and performed only when necessary. It therefore provides a favorable scaling for the computational complexity in simulating large reaction networks. We benchmark our new algorithm with the state of the art algorithms available in literature to demonstrate its applicability and efficiency.

  3. Gaussian Cubes: Real-Time Modeling for Visual Exploration of Large Multidimensional Datasets.

    PubMed

    Wang, Zhe; Ferreira, Nivan; Wei, Youhao; Bhaskar, Aarthy Sankari; Scheidegger, Carlos

    2017-01-01

    Recently proposed techniques have finally made it possible for analysts to interactively explore very large datasets in real time. However powerful, the class of analyses these systems enable is somewhat limited: specifically, one can only quickly obtain plots such as histograms and heatmaps. In this paper, we contribute Gaussian Cubes, which significantly improves on state-of-the-art systems by providing interactive modeling capabilities, which include but are not limited to linear least squares and principal components analysis (PCA). The fundamental insight in Gaussian Cubes is that instead of precomputing counts of many data subsets (as state-of-the-art systems do), Gaussian Cubes precomputes the best multivariate Gaussian for the respective data subsets. As an example, Gaussian Cubes can fit hundreds of models over millions of data points in well under a second, enabling novel types of visual exploration of such large datasets. We present three case studies that highlight the visualization and analysis capabilities in Gaussian Cubes, using earthquake safety simulations, astronomical catalogs, and transportation statistics. The dataset sizes range around one hundred million elements and 5 to 10 dimensions. We present extensive performance results, a discussion of the limitations in Gaussian Cubes, and future research directions.

  4. A New Paradigm for Supergranulation Derived from Large-Distance Time-Distance Helioseismology: Pancakes

    NASA Technical Reports Server (NTRS)

    Duvall, Thomas L.; Hanasoge, Shravan M.

    2012-01-01

    With large separations (10-24 deg heliocentric), it has proven possible to cleanly separate the horizontal and vertical components of supergranular flow with time-distance helioseismology. These measurements require very broad filters in the k-$\\omega$ power spectrum as apparently supergranulation scatters waves over a large area of the power spectrum. By picking locations of supergranulation as peaks in the horizontal divergence signal derived from f-mode waves, it is possible to simultaneously obtain average properties of supergranules and a high signal/noise ratio by averaging over many cells. By comparing ray-theory forward modeling with HMI measurements, an average supergranule model with a peak upflow of 240 m/s at cell center at a depth of 2.3 Mm and a peak horizontal outflow of 700 m/s at a depth of 1.6 Mm. This upflow is a factor of 20 larger than the measured photospheric upflow. These results may not be consistent with earlier measurements using much shorter separations (<5 deg heliocentric). With a 30 Mm horizontal extent and a few Mm in depth, the cells might be characterized as thick pancakes.

  5. Numerical simulation of pseudoelastic shape memory alloys using the large time increment method

    NASA Astrophysics Data System (ADS)

    Gu, Xiaojun; Zhang, Weihong; Zaki, Wael; Moumni, Ziad

    2017-04-01

    The paper presents a numerical implementation of the large time increment (LATIN) method for the simulation of shape memory alloys (SMAs) in the pseudoelastic range. The method was initially proposed as an alternative to the conventional incremental approach for the integration of nonlinear constitutive models. It is adapted here for the simulation of pseudoelastic SMA behavior using the Zaki-Moumni model and is shown to be especially useful in situations where the phase transformation process presents little or lack of hardening. In these situations, a slight stress variation in a load increment can result in large variations of strain and local state variables, which may lead to difficulties in numerical convergence. In contrast to the conventional incremental method, the LATIN method solve the global equilibrium and local consistency conditions sequentially for the entire loading path. The achieved solution must satisfy the conditions of static and kinematic admissibility and consistency simultaneously after several iterations. 3D numerical implementation is accomplished using an implicit algorithm and is then used for finite element simulation using the software Abaqus. Computational tests demonstrate the ability of this approach to simulate SMAs presenting flat phase transformation plateaus and subjected to complex loading cases, such as the quasi-static behavior of a stent structure. Some numerical results are contrasted to those obtained using step-by-step incremental integration.

  6. Linear noise approximation is valid over limited times for any chemical system that is sufficiently large.

    PubMed

    Wallace, E W J; Gillespie, D T; Sanft, K R; Petzold, L R

    2012-08-01

    The linear noise approximation (LNA) is a way of approximating the stochastic time evolution of a well-stirred chemically reacting system. It can be obtained either as the lowest order correction to the deterministic chemical reaction rate equation (RRE) in van Kampen's system-size expansion of the chemical master equation (CME), or by linearising the two-term-truncated chemical Kramers-Moyal equation. However, neither of those derivations sheds much light on the validity of the LNA. The problematic character of the system-size expansion of the CME for some chemical systems, the arbitrariness of truncating the chemical Kramers-Moyal equation at two terms, and the sometimes poor agreement of the LNA with the solution of the CME, have all raised concerns about the validity and usefulness of the LNA. Here, the authors argue that these concerns can be resolved by viewing the LNA as an approximation of the chemical Langevin equation (CLE). This view is already implicit in Gardiner's derivation of the LNA from the truncated Kramers-Moyal equation, as that equation is mathematically equivalent to the CLE. However, the CLE can be more convincingly derived in a way that does not involve either the truncated Kramers-Moyal equation or the system-size expansion. This derivation shows that the CLE will be valid, at least for a limited span of time, for any system that is sufficiently close to the thermodynamic (large-system) limit. The relatively easy derivation of the LNA from the CLE shows that the LNA shares the CLE's conditions of validity, and it also suggests that what the LNA really gives us is a description of the initial departure of the CLE from the RRE as we back away from the thermodynamic limit to a large but finite system. The authors show that this approach to the LNA simplifies its derivation, clarifies its limitations, and affords an easier path to its solution.

  7. Geographic variation in marine invasions among large estuaries: effects of ships and time.

    PubMed

    Ruiz, Gregory M; Fofonoff, Paul W; Ashton, Gail; Minton, Mark S; Miller, A Whitman

    2013-03-01

    Coastal regions exhibit strong geographic patterns of nonnative species richness. Most invasions in marine ecosystems are known from bays and estuaries, where ship-mediated transfers (on hulls or in ballasted materials) have been a dominant vector of species introductions. Conspicuous spatial differences in nonnative species richness exist among bays, but the quantitative relationship between invasion magnitude and shipping activity across sites is largely unexplored. Using data on marine invasions (for invertebrates and algae) and commercial shipping across 16 large bays in the United States, we estimated (1) geographic variation in nonnative species richness attributed to ships, controlling for effects of salinity and other vectors, (2) changes through time in geographic variation of these ship-mediated invasions, and (3) effects of commercial ship traffic and ballast water discharge magnitude on nonnative species richness. For all nonnative species together (regardless of vector, salinity, or time period), species richness differed among U.S. coasts, being significantly greater for Pacific Coast bays than Atlantic or Gulf Coast bays. This difference also existed when considering only species attributed to shipping (or ballast water), controlling for time and salinity. Variation in nonnative species richness among Pacific Coast bays was strongly affected by these same criteria. San Francisco Bay, California, had over 200 documented nonnative species, more than twice that reported for other bays, but many species were associated with other (non-shipping) vectors or the extensive low-salinity habitats (unavailable in some bays). When considering only ship- or ballast-mediated introductions in high-salinity waters, the rate of newly detected invasions in San Francisco Bay has converged increasingly through time on that for other Pacific Coast bays, appearing no different since 1982. Considering all 16 bays together, there was no relationship between either (1

  8. The biotic effects of large bolide impacts: size versus time and place

    NASA Astrophysics Data System (ADS)

    Walkden, Gordon; Parker, Julian

    2008-10-01

    In estimating the biotic effects of large terrestrial impacts we are reliant upon apparent crater diameter as a proxy for impact magnitude. This underlies the ‘kill-curve’ approach which graphs crater diameter directly against likely percentage losses of taxa. However, crater diameter is a complex product of syn- and post-impact processes that can be site-dependent. Furthermore, location (global positioning) and timing (moment in geological history) also strongly influence biotic effects. We examine four of our largest and best-documented Phanerozoic impacts to explore this more holistic size time place relationship. Only the c. 180 km end-Cretaceous Chicxulub crater (Mexico) links to any substantial immediate extinction and some of the worst effects stem from where it struck the planet (a continental margin carbonate platform site) and when (a time of high regional and global biodiversity). Both the c. 100 km late Triassic Manicouagan crater in NE Canada (arid continental interior, low regional and world biodiversity) and the c. 35 Ma 100 km Popigai crater, Siberia (continental arctic desert) provide much less damaging scenarios. However the c. 90 km Chesapeake Bay crater, Eastern USA (also c. 35 Ma) marks a far more sensitive (Chicxulub-like) site but it also proved relatively benign. Here the rheologically varied shallow marine target site produced an anomalously broad crater, and the scale of the impact has evidently been overestimated. We offer a new approach to the graphical prediction of biotic risk in which both crater diameter and a generalised time/place factor we term ‘vulnerability’ are variables.

  9. Thermal motion in proteins: Large effects on the time-averaged interaction energies

    SciTech Connect

    Goethe, Martin Rubi, J. Miguel; Fita, Ignacio

    2016-03-15

    As a consequence of thermal motion, inter-atomic distances in proteins fluctuate strongly around their average values, and hence, also interaction energies (i.e. the pair-potentials evaluated at the fluctuating distances) are not constant in time but exhibit pronounced fluctuations. These fluctuations cause that time-averaged interaction energies do generally not coincide with the energy values obtained by evaluating the pair-potentials at the average distances. More precisely, time-averaged interaction energies behave typically smoother in terms of the average distance than the corresponding pair-potentials. This averaging effect is referred to as the thermal smoothing effect. Here, we estimate the strength of the thermal smoothing effect on the Lennard-Jones pair-potential for globular proteins at ambient conditions using x-ray diffraction and simulation data of a representative set of proteins. For specific atom species, we find a significant smoothing effect where the time-averaged interaction energy of a single atom pair can differ by various tens of cal/mol from the Lennard-Jones potential at the average distance. Importantly, we observe a dependency of the effect on the local environment of the involved atoms. The effect is typically weaker for bulky backbone atoms in beta sheets than for side-chain atoms belonging to other secondary structure on the surface of the protein. The results of this work have important practical implications for protein software relying on free energy expressions. We show that the accuracy of free energy expressions can largely be increased by introducing environment specific Lennard-Jones parameters accounting for the fact that the typical thermal motion of protein atoms depends strongly on their local environment.

  10. Large Area Flat Panel Imaging Detectors for Astronomy and Night Time Sensing

    NASA Astrophysics Data System (ADS)

    Siegmund, O.; McPhate, J.; Frisch, H.; Elam, J.; Mane, A.; Wagner, R.; Varner, G.

    2013-09-01

    Sealed tube photo-sensing detectors for optical/IR detection have applications in astronomy, nighttime remote reconnaissance, and airborne/space situational awareness. The potential development of large area photon counting, imaging, timing detectors has significance for these applications and a number of other areas (High energy particle detection (RICH), biological single-molecule fluorescence lifetime imaging microscopy, neutron imaging, time of flight mass spectroscopy, diffraction imaging). We will present details of progress towards the development of a 20 cm sealed tube optical detector with nanoengineered microchannel plates for photon counting, imaging and sub-ns event time stamping. In the operational scheme of the photodetector incoming light passes through an entrance window and interacts with a semitransparent photocathode on the inside of the window. The photoelectrons emitted are accelerated across a proximity gap and are detected by an MCP pair. The pair of novel borosilicate substrate MCPs are functionalized by atomic layer deposition (ALD), and amplify the signal and the resulting electron cloud is detected by a conductive strip line anode for determination of the event positions and the time of arrival. The physical package is ~ 25 x 25 cm but only 1.5 cm thick. Development of such a device in a square 20 cm format presents challenges: hermetic sealing to a large entrance window, a 20 cm semitransparent photocathode with good efficiency and uniformity, 20 cm MCPs with reasonable cost and performance, robust construction to preserve high vacuum and withstand an atmosphere pressure differential. We will discuss the schemes developed to address these issues and present the results for the first test devices. The novel microchannel plates employing borosilicate micro-capillary arrays provide many performance characteristics typical of conventional MCPs, but have been made in sizes up to 20 cm, have low intrinsic background (0.08 events cm2 s-1) and

  11. Solar Wind and IMF Control of Large-Scale Ionospheric Currents and Their Time Variations

    NASA Astrophysics Data System (ADS)

    Juusola, L.; Kauristie, K.; Tanskanen, E.; Partamies, N.; Viljanen, A.; Andréeová, K.; van de Kamp, M.; Vanhamäki, H.; Milan, S. E.; Lester, M.; Grocott, A.; Imber, S. M.

    2014-12-01

    Patterns of high-latitude ionospheric currents are a manifestation of the solar wind-magnetosphere-ionosphere coupling. Rapid variations of the currents are associated with geomagnetically induced currents (GIC) in technological conductor systems and displays of bright, diverse auroras. One advantage of a ground-based magnetometer network over a low-orbit satellite is the possibility to distinguish between temporal and spatial variations in the data. Although ground magnetic field data can only yield distributions of ionospheric equivalent currents instead of the full horizontal and field-aligned current density, estimates for these can be obtained, under certain assumptions. We use data (1994-2013) from the ground-based IMAGE magnetometer network to derive statistical distributions of the large-scale ionospheric equivalent current density and its time-derivative as well as estimates for the field-aligned current density. These are compared with and validated against horizontal and field-aligned current density distributions obtained from low-orbit CHAMP satellite magnetic field data (2000-2010) and convection maps obtained from SuperDARN radar data (2000-2010). The ground-based distributions reveal a strong dependence of the dayside variations on radial interplanetary magnetic field (IMF) orientation and solar wind speed. The spatial distribution of enhanced nightside activity agrees with that of the average substorm bulge and depends on solar wind energy input into the magnetosphere. The most intense time variation events are related to substorm activity and occur on the nightside.

  12. Large vestibular aqueduct syndrome: Impedance changes over time with different cochlear implant electrode arrays.

    PubMed

    Powell, Harry R F; Birman, Catherine S

    2015-01-01

    The aim of this study was to assess if large vestibular aqueduct syndrome (LVAS), with the increase in perilymphatic pressure, affects impedance changes over time with different types of Cochlear(®) implant electrode arrays Contour, Straight, and CI 422. To report speech perception outcomes for these cochlear implant recipients. Retrospective case review of impedance levels and categories of auditory performance. Impedance data were collected at switch on, 1 month, 3, 6, 12, and 24 months after cochlear implantation and compared with control (non-LVAS cochlear implant recipient) data for each array type. Forty-seven patients with exclusive LVAS and no other vestibulocochlear abnormalities or other identifiable cause of deafness were eligible for inclusion in the study. In LVAS patients, there was a significant difference in impedance between the three types of device (P < 0.0001). Time since switch on was associated with a decrease in impedance for all three devices (P < 0.0001). The mean impedance reduced between switch on and 1 month and remained relatively constant thereafter. Sound variation with softening of sounds was seen in four CI 422 (Straight Research Array) recipients due to ongoing fluctuations in electrode compliance. For all three array types, there was no significant difference in the mean impedance between the LVAS patients and controls over the first 12 months. In keeping with previous studies cochlear implant recipients with LVAS hear very well through the cochlear implant.

  13. Spin-relaxation time in materials with broken inversion symmetry and large spin-orbit coupling.

    PubMed

    Szolnoki, Lénárd; Kiss, Annamária; Dóra, Balázs; Simon, Ferenc

    2017-08-30

    We study the spin-relaxation time in materials where a large spin-orbit coupling (SOC) is present which breaks the spatial inversion symmetry. Such a spin-orbit coupling is realized in zincblende structures and heterostructures with a transversal electric field and the spin relaxation is usually described by the so-called D'yakonov-Perel' (DP) mechanism. We combine a Monte Carlo method and diagrammatic calculation based approaches in our study; the former tracks the time evolution of electron spins in a quasiparticle dynamics simulation in the presence of the built-in spin-orbit magnetic fields and the latter builds on the spin-diffusion propagator by Burkov and Balents. Remarkably, we find a parameter free quantitative agreement between the two approaches and it also returns the conventional result of the DP mechanism in the appropriate limit. We discuss the full phase space of spin relaxation as a function of SOC strength, its distribution, and the magnitude of the momentum relaxation rate. This allows us to identify two novel spin-relaxation regimes; where spin relaxation is strongly non-exponential and the spin relaxation equals the momentum relaxation. A compelling analogy between the spin-relaxation theory and the NMR motional narrowing is highlighted.

  14. Representation of solutions and large-time behavior for fully nonlocal diffusion equations

    NASA Astrophysics Data System (ADS)

    Kemppainen, Jukka; Siljander, Juhana; Zacher, Rico

    2017-07-01

    We study the Cauchy problem for a nonlocal heat equation, which is of fractional order both in space and time. We prove four main theorems: a representation formula for classical solutions a quantitative decay rate at which the solution tends to the fundamental solution optimal L2-decay of mild solutions in all dimensions L2-decay of weak solutions via energy methods. The first result relies on a delicate analysis of the definition of classical solutions. After proving the representation formula we carefully analyze the integral representation to obtain the quantitative decay rates of (ii). Next we use Fourier analysis techniques to obtain the optimal decay rate for mild solutions. Here we encounter the critical dimension phenomenon where the decay rate attains the decay rate of that in a bounded domain for large enough dimensions. Consequently, the decay rate does not anymore improve when the dimension increases. The theory is markedly different from that of the standard caloric functions and this substantially complicates the analysis. Finally, we use energy estimates and a comparison principle to prove a quantitative decay rate for weak solutions defined via a variational formulation. Our main idea is to show that the L2-norm is actually a subsolution to a purely time-fractional problem which allows us to use the known theory to obtain the result.

  15. Global Static Indexing for Real-Time Exploration of Very Large Regular Grids

    SciTech Connect

    Pascucci, V; Frank, R

    2001-07-23

    In this paper we introduce a new indexing scheme for progressive traversal and visualization of large regular grids. We demonstrate the potential of our approach by providing a tool that displays at interactive rates planar slices of scalar field data with very modest computing resources. We obtain unprecedented results both in terms of absolute performance and, more importantly, in terms of scalability. On a laptop computer we provide real time interaction with a 2048{sup 3} grid (8 Giga-nodes) using only 20MB of memory. On an SGI Onyx we slice interactively an 8192{sup 3} grid (1/2 tera-nodes) using only 60MB of memory. The scheme relies simply on the determination of an appropriate reordering of the rectilinear grid data and a progressive construction of the output slice. The reordering minimizes the amount of I/O performed during the out-of-core computation. The progressive and asynchronous computation of the output provides flexible quality/speed tradeoffs and a time-critical and interruptible user interface.

  16. Determinants and Time Trends for Ischaemic and Haemorrhagic Stroke in a Large Chinese Population

    PubMed Central

    Guo, Yutao; Wang, Hao; Tao, Tao; Tian, Yingchun; Wang, Yutang; Chen, Yundai; Lip, Gregory Y. H.

    2016-01-01

    Background The clinical epidemiology of stroke has been widely investigated in Caucasian populations, but the changes over time in the proportion of ischaemic to haemorrhagic strokes is less clear, especially in the Chinese population. Aims Our objective was to study the determinants and time trends for ischaemic and haemorrhagic stroke, in relation to age, in a large Chinese population cohort. Methods Using a medical insurance database in the southwest of China from 2001 to 2012, time trends in age-adjusted ischaemic and haemorrhagic stroke incidence and the contributing risk factors associated with age were investigated. Results Among 425,901 individuals without prior stroke (52.4% male, median age 54), the rate of ischaemic stroke (per 1000 patient-years) decreased between 2002–2007, then remained broadly similar between 2008–2012. The rate of haemorrhagic stroke showed a similar trend, being approximately 1.3–1.9 from 2008–2012. Compared to patients age<65, ischaemic and haemorrhagic stroke incidences (rate, 95% confidential interval, CI) were higher in the elderly population (age <65 versus age ≥65: ischaemic: 3.64, 3.33–4.00, vs 14.33, 14.01–14.60; haemorrhagic: 1.09, 1.00–1.10 vs 2.52,2.40–2.70, respectively, both p<0.001). There were no significant differences in haemorrhagic stroke rates between the elderly and the very elderly population. Ischaemic and haemorrhagic stroke shared similar risk factors (age, hypertension, coronary artery disease (CAD), vascular disease, and diabetes mellitus) (all p<0.05). In subjects age<75 years, CAD (7.17, 4.14–12.37) and diabetes mellitus (3.27, 2.42–4.42) contributed most to the developing of haemorrhagic stroke (all p<0.001). Amongst the very elderly, vascular disease (2.24, 1.49–3.37) was an additional major risk factor for haemorrhagic stroke, together with CAD and diabetes mellitus (all p<0.001). Conclusion In this large Chinese cohort, there was an increased risk of ischaemic stroke compared

  17. Insights From Field Geology Into the Styles and Timings of Large Silicic Explosive `Supereruptions'

    NASA Astrophysics Data System (ADS)

    Wilson, C. J.

    2006-12-01

    The evocative terms `supereruption' (and `supervolcano'), whilst eminently saleable to the media, conceal the fact that, apart from knowing that such large eruptions (>300 km3, magma) actually have occurred, we understand very little about the dynamics of such events. Field studies of 3 supereruption deposits suggest that we are missing information on the timing and eruptive styles that is essential in assessing the dynamics and impacts of past and future large eruptions. The 26.5 ka Oruanui eruption in New Zealand (ca. 530 km3, magma) shows evidence in the form of erosion intervals and/or reworked horizons for spasmodic activity, including a hiatus of weeks plus other shorter breaks, that interrupted 10 phases of activity. Following the plinian fall unit of phase 1, there was a time break long enough for local reworking (and possibly emplacement of a small dome), thus of the order of weeks in duration. Other breaks, during which minor wind- or water-reworking took place are observed between phases 4 and 5, and 9 and 10, and were of the order of days. Two other horizons saw the complete settling out of 10-20 micron-sized ash particles before commencement of the next phase of the eruption, and thus may represent breaks of hours. The whole eruption was a series of large-scale outbreaks of generally increasing vigor, daisy-chained to form a single geological event, but one which would represent recurrent hazards, and uncertainties in eruptive activity if repeated today. The 0.76 Ma Bishop Tuff eruption (ca. 600 km3, magma), on the other hand, displays evidence only for one short time break, represented by settling out of fine ash at the top of a plinian pumice fall unit. Most of the eruption volume may have been emplaced over only about 6 days. Such an eruption, although catastrophic when placed in today's societal context, at least was over relatively rapidly. The immense 2.06 Ma Huckleberry Ridge Tuff (HRT) eruption (ca. 2500 km3, magma) shows evidence for prolonged

  18. Determination of paleoseismic activity over a large time-scale: Fault scarp dating with 36Cl

    NASA Astrophysics Data System (ADS)

    Mozafari Amiri, Nasim; Tikhomirov, Dmitry; Sümer, Ökmen; Özkaymak, Çaǧlar; Uzel, Bora; Ivy-Ochs, Susan; Vockenhuber, Christof; Sözbilir, Hasan; Akçar, Naki

    2016-04-01

    Bedrock fault scarps are the most direct evidence of past earthquakes to reconstruct seismic activity in a large time-scale using cosmogenic 36Cl dating if built in carbonates. For this method, a surface along the fault scarp with a minimum amount of erosion is required to be chosen as an ideal target point. The section of the fault selected for sampling should cover at least two meters of the fault surface from the lower part of the scarp, where intersects with colluvium wedge. Ideally, sampling should be performed on a continuous strip along the direction of the fault slip direction. First, samples of 10 cm high and 15 cm wide are marked on the fault surface. Then, they are collected using cutters, hammer and chisel in a thickness of 3 cm. The main geometrical factors of scarp dip, scarp height, top surface dip and colluvium dip are also measured. Topographic shielding in the sampling spot is important to be estimated as well. Moreover, density of the fault scarp and colluvium are calculated. The physical and chemical preparations are carried in laboratory for AMS and chemical analysis of the samples. A Matlab® code is used for modelling of seismically active periods based on increasing production rate of 36Cl following each rupture, when a buried section of a fault is exposed. Therefore, by measuring the amount of cosmogenic 36Cl versus height, the timing of major ruptures and their offsets are determined. In our study, Manastır, Mugırtepe and Rahmiye faults in Gediz graben, Priene-Sazlı, Kalafat and Yavansu faults in Büyük Menderes graben and Ören fault in Gökava half-graben have been examined in the seismically active region of Western Turkey. Our results reconstruct at least five periods of high seismic activity during the Holocene time, three of which reveal seismic ruptures beyond the historical pre-existing data.

  19. Utility of Closed Suction Pelvic Drains at Time of Large Bowel Resection for Ovarian Cancer

    PubMed Central

    Kalogera, Eleftheria; Dowdy, Sean C.; Mariani, Andrea; Aletti, Giovanni; Bakkum-Gamez, Jamie N.; Cliby, William A.

    2012-01-01

    Objective To test the hypothesis that the use of closed suction pelvic drains placed at time of large bowel resection (LBR) for ovarian cancer (OC) decrease morbidity following anastomotic leak (AL). Methods Consecutive cases of LBR for OC between 01/01/1994 and 06/20/2011 were retrospectively identified. Drains were routinely used until bowel movement. AL was defined as: 1) feculent fluid from drains/wound/vagina, 2) radiographic evidence of AL, or 3) AL found at reoperation. Descriptive statistics, Wilcoxon rank-sum, Pearson's chi-square and Fisher's exact test were used. Results 43 cases met inclusion criteria. AL was characterized by method of diagnosis as follows: change in drain output only (DO, n=8); change in drain output associated with ambiguous clinical signs/symptoms (D-SSX, n=11); or clinical signs/symptoms only (SSX, n=24). The sensitivity of drains in diagnosing AL was 50%. Time to diagnosis was earlier in DO/D-SSX (median 7 vs. 11 days, P=0.003), however, no significant differences were observed in rates of reoperation, length of stay, time to chemotherapy (TTC), and 30- and 90-day mortality between DO/D-SSX and SSX. Comparing cases where no drains were placed (n=5) vs. those with drain (n=38), we observed no differences in outcomes. TTC though statistically significant (47 vs. 59 days, P=0.023) was not clinically significant. Conclusions Though a change in drain output correlated with earlier diagnosis, this did not appear to impact overall outcomes. We did not find strong evidence supporting routine prolonged drainage after LBR for OC. Additionally, absence of change in drain output does not rule out presence of AL. PMID:22617523

  20. Impact of Expanding the Prehospital Stroke Bypass Time Window in a Large Geographic Region.

    PubMed

    Stiell, Ian G; Clement, Catherine M; Campbell, Kristy; Sharma, Mukul; Socha, Doug; Sivilotti, Marco L A; Jin, Albert; Perry, Jeffrey J; Lumsden, Jim; Martin, Cally; Froats, Mark; Dionne, Richard; Trickett, John

    2017-03-01

    The Ontario Acute Stroke Medical Redirect Paramedic Protocol (ASMRPP) was revised to allow paramedics to bypass to designated stroke centers if total transport time would be <2 hours and total time from symptom onset <3.5 hours. We sought to evaluate the impact and safety of implementing the Revised ASMRPP. We conducted a 12-month implementation study involving prehospital patients presenting with possible stroke symptoms. A total of 1317 basic and advanced life support paramedics, of 9 land services in 10 rural counties and 5 cities, used the Revised ASMRPP to take appropriate patients directly to 6 designated stroke centers. We enrolled 1277 patients with 98.8% paramedic compliance in form completion. Of these, 755 (61.2%) met the redirect criteria and had these characteristics: mean age 72.1 (range 16-101), male 51.1%, mean time scene to hospital 16.7 minutes (range 0-92). Paramedics demonstrated excellent interobserver agreement (κ, 0.94; 95% confidence interval, 0.91-0.96) and 97.9% accuracy in interpretation of the Revised ASMRPP. Prehospital adverse events occurred in 14.7% of patients, but few were life-threatening. Overall, 71.4% of 755 cases had a stroke code activated at the hospital and 23.2% received thrombolysis. For the 189 potential stroke patients picked up in 1 city, the ASMRPP classified thrombolysis administration with sensitivity 100% and specificity 37.3% and a final diagnosis of stroke, with sensitivity 86.1% and specificity 41.9%. In a large urban-rural area with 9 paramedic services, we demonstrated accurate, safe, and effective implementation of the Revised ASMRPP. These revisions will allow more patients with stroke to benefit from early treatment. © 2017 American Heart Association, Inc.

  1. Energy levels and lifetimes of Nd IV, Pm IV, Sm IV, and Eu IV

    SciTech Connect

    Dzuba, V. A.; Safronova, U. I.; Johnson, W. R.

    2003-09-01

    To address the shortage of experimental data for electron spectra of triply ionized rare-earth elements we have calculated energy levels and lifetimes of 4f{sup n+1} and 4f{sup n}5d configurations of Nd IV (n=2), Pm IV (n=3), Sm IV (n=4), and Eu IV (n=5) using Hartree-Fock and configuration-interaction methods. To control the accuracy of our calculations we also performed similar calculations for Pr III, Nd III, and Sm III, for which experimental data are available. The results are important, in particular, for physics of magnetic garnets.

  2. Likelihood of Null Effects of Large NHLBI Clinical Trials Has Increased over Time

    PubMed Central

    Kaplan, Robert M.; Irvin, Veronica L.

    2015-01-01

    Background We explore whether the number of null results in large National Heart Lung, and Blood Institute (NHLBI) funded trials has increased over time. Methods We identified all large NHLBI supported RCTs between 1970 and 2012 evaluating drugs or dietary supplements for the treatment or prevention of cardiovascular disease. Trials were included if direct costs >$500,000/year, participants were adult humans, and the primary outcome was cardiovascular risk, disease or death. The 55 trials meeting these criteria were coded for whether they were published prior to or after the year 2000, whether they registered in clinicaltrials.gov prior to publication, used active or placebo comparator, and whether or not the trial had industry co-sponsorship. We tabulated whether the study reported a positive, negative, or null result on the primary outcome variable and for total mortality. Results 17 of 30 studies (57%) published prior to 2000 showed a significant benefit of intervention on the primary outcome in comparison to only 2 among the 25 (8%) trials published after 2000 (χ2=12.2,df= 1, p=0.0005). There has been no change in the proportion of trials that compared treatment to placebo versus active comparator. Industry co-sponsorship was unrelated to the probability of reporting a significant benefit. Pre-registration in clinical trials.gov was strongly associated with the trend toward null findings. Conclusions The number NHLBI trials reporting positive results declined after the year 2000. Prospective declaration of outcomes in RCTs, and the adoption of transparent reporting standards, as required by clinicaltrials.gov, may have contributed to the trend toward null findings. PMID:26244868

  3. Timing gamma-ray pulsars with the Fermi large area telescope: Timing noise and astrometry

    SciTech Connect

    Kerr, Matthew; Ray, P. S.; Johnston, S.; Shannon, R. M.; Camilo, F.

    2015-11-25

    We have constructed timing solutions for 81 γ-ray pulsars covering more than five years of Fermi data. The sample includes 37 radio-quiet or radio-faint pulsars which cannot be timed with other telescopes. These timing solutions and the corresponding pulse times of arrival are prerequisites for further study, e.g., phase-resolved spectroscopy or searches for mode switches. Many γ-ray pulsars are strongly affected by timing noise (TN), and we present a new method for characterizing the noise process and mitigating its effects on other facets of the timing model. We present an analysis of TN over the population using a new metric for characterizing its strength and spectral shape, namely, its time-domain correlation. The dependence of the strength on ν and $\\dot{\

  4. Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. IV. Hβ Time Lags and Implications for Super-Eddington Accretion

    NASA Astrophysics Data System (ADS)

    Du, Pu; Hu, Chen; Lu, Kai-Xing; Huang, Ying-Ke; Cheng, Cheng; Qiu, Jie; Li, Yan-Rong; Zhang, Yang-Wei; Fan, Xu-Liang; Bai, Jin-Ming; Bian, Wei-Hao; Yuan, Ye-Fei; Kaspi, Shai; Ho, Luis C.; Netzer, Hagai; Wang, Jian-Min; SEAMBH Collaboration

    2015-06-01

    We have completed two years of photometric and spectroscopic monitoring of a large number of active galactic nuclei (AGNs) with very high accretion rates. In this paper, we report on the result of the second phase of the campaign, during 2013-2014, and the measurements of five new Hβ time lags out of eight monitored AGNs. All five objects were identified as super-Eddington accreting massive black holes (SEAMBHs). The highest measured accretion rates for the objects in this campaign are \\mathscr{\\dot{M}} {\\mkern 1mu} ≳ 200, where \\mathscr{\\dot{M}} {\\mkern 1mu} ={{\\dot{M}}\\bullet }/{{L}Edd}{{c}-2}, {{\\dot{M}}\\bullet } is the mass accretion rates, {{L}Edd} is the Eddington luminosity and c is the speed of light. We find that the Hβ time lags in SEAMBHs are significantly shorter than those measured in sub-Eddington AGNs, and the deviations increase with increasing accretion rates. Thus, the relationship between broad-line region size ({{R}_{Hβ }}) and optical luminosity at 5100 Å, {{R}_{Hβ }}-{{L}5100}, requires accretion rate as an additional parameter. We propose that much of the effect may be due to the strong anisotropy of the emitted slim-disk radiation. Scaling {{R}_{Hβ }} by the gravitational radius of the black hole (BH), we define a new radius-mass parameter (Y) and show that it saturates at a critical accretion rate of \\mathscr{\\dot{M}} {\\mkern 1mu} {{}c}=6˜ 30, indicating a transition from thin to slim accretion disk and a saturated luminosity of the slim disks. The parameter Y is a very useful probe for understanding the various types of accretion onto massive BHs. We briefly comment on implications to the general population of super-Eddington AGNs in the universe and applications to cosmology.

  5. Large-deviation joint statistics of the finite-time Lyapunov spectrum in isotropic turbulence

    NASA Astrophysics Data System (ADS)

    Johnson, Perry L.; Meneveau, Charles

    2015-08-01

    One of the hallmarks of turbulent flows is the chaotic behavior of fluid particle paths with exponentially growing separation among them while their distance does not exceed the viscous range. The maximal (positive) Lyapunov exponent represents the average strength of the exponential growth rate, while fluctuations in the rate of growth are characterized by the finite-time Lyapunov exponents (FTLEs). In the last decade or so, the notion of Lagrangian coherent structures (which are often computed using FTLEs) has gained attention as a tool for visualizing coherent trajectory patterns in a flow and distinguishing regions of the flow with different mixing properties. A quantitative statistical characterization of FTLEs can be accomplished using the statistical theory of large deviations, based on the so-called Cramér function. To obtain the Cramér function from data, we use both the method based on measuring moments and measuring histograms and introduce a finite-size correction to the histogram-based method. We generalize the existing univariate formalism to the joint distributions of the two FTLEs needed to fully specify the Lyapunov spectrum in 3D flows. The joint Cramér function of turbulence is measured from two direct numerical simulation datasets of isotropic turbulence. Results are compared with joint statistics of FTLEs computed using only the symmetric part of the velocity gradient tensor, as well as with joint statistics of instantaneous strain-rate eigenvalues. When using only the strain contribution of the velocity gradient, the maximal FTLE nearly doubles in magnitude, highlighting the role of rotation in de-correlating the fluid deformations along particle paths. We also extend the large-deviation theory to study the statistics of the ratio of FTLEs. The most likely ratio of the FTLEs λ1 : λ2 : λ3 is shown to be about 4:1:-5, compared to about 8:3:-11 when using only the strain-rate tensor for calculating fluid volume deformations. The results

  6. Large-deviation joint statistics of the finite-time Lyapunov spectrum in isotropic turbulence

    SciTech Connect

    Johnson, Perry L. Meneveau, Charles

    2015-08-15

    One of the hallmarks of turbulent flows is the chaotic behavior of fluid particle paths with exponentially growing separation among them while their distance does not exceed the viscous range. The maximal (positive) Lyapunov exponent represents the average strength of the exponential growth rate, while fluctuations in the rate of growth are characterized by the finite-time Lyapunov exponents (FTLEs). In the last decade or so, the notion of Lagrangian coherent structures (which are often computed using FTLEs) has gained attention as a tool for visualizing coherent trajectory patterns in a flow and distinguishing regions of the flow with different mixing properties. A quantitative statistical characterization of FTLEs can be accomplished using the statistical theory of large deviations, based on the so-called Cramér function. To obtain the Cramér function from data, we use both the method based on measuring moments and measuring histograms and introduce a finite-size correction to the histogram-based method. We generalize the existing univariate formalism to the joint distributions of the two FTLEs needed to fully specify the Lyapunov spectrum in 3D flows. The joint Cramér function of turbulence is measured from two direct numerical simulation datasets of isotropic turbulence. Results are compared with joint statistics of FTLEs computed using only the symmetric part of the velocity gradient tensor, as well as with joint statistics of instantaneous strain-rate eigenvalues. When using only the strain contribution of the velocity gradient, the maximal FTLE nearly doubles in magnitude, highlighting the role of rotation in de-correlating the fluid deformations along particle paths. We also extend the large-deviation theory to study the statistics of the ratio of FTLEs. The most likely ratio of the FTLEs λ{sub 1} : λ{sub 2} : λ{sub 3} is shown to be about 4:1:−5, compared to about 8:3:−11 when using only the strain-rate tensor for calculating fluid volume

  7. Distribution and residence times of large woody debris along South River, Shenandoah Valley, Virginia

    NASA Astrophysics Data System (ADS)

    Hess, J.; Pizzuto, J.

    2006-12-01

    Numerous studies on large woody debris (LWD) have focused on forested mountain streams located in the Pacific Northwest. Wood in these streams typically form log jams that have a profound impact on stream morphology, promoting channel stability and forcing pools. However, studies are sparse on larger rivers where LWD occurs primarily as individual pieces. Even less is known about the residence times of LWD in these settings. This study focuses on the use of dendrochronology to determine the rates of LWD recruitment and LWD residence times. Located in the Shenandoah Valley of Virginia, the South River is a fourth order stream with a drainage area of over 600 km2 at its confluence with the South Fork Shenandoah River. The riparian zone is dominated by agriculture. Agricultural land use creates a distribution of LWD unlike that of forested streams, consisting primarily of isolated pieces and small jams versus larger jams. Four species of trees are dominant at South River: sycamore (Platanus occidentalis), silver maple (Acer saccharinum), boxelder (Acer negundo) and black walnut (Juglans nigra). Average diameters of LWD are 32 cm with lengths averaging 6-7 m. At the South River, LWD has no influence on channel morphology, but wood traps fine-grained sediment (storing 16% of the river's annual load) and associated contaminants making it the most significant mechanism for storing clay and silt within the channel perimeter. Sixty to seventy-five percent of LWD occurs in pools, while 10-20% occurs in riffles. Most of the wood falls from adjacent banks by both natural processes and agricultural practices. Preliminary dating results indicate that LWD reside in the channel a minimum of 15 years.

  8. Storm-time Large-Scale Birkeland Currents: Salient Dynamics in Grand Challenge Events

    NASA Astrophysics Data System (ADS)

    Korth, H.; Anderson, B. J.; Waters, C. L.; Barnes, R. J.

    2015-12-01

    The Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) provides continuous global observations of Birkeland currents on a 10 minute cadence. During geomagnetic storms, currents intensify to over 15 MA, are dynamic both in intensity and distribution, and exhibit features not discernible in statistical analyses. For all of the subject grand challenge storms, AMPERE data reveal a number of novel phenomena illustrating the profound dynamics of the storm-time system. Storm-time onsets associated with shock arrivals are often very prompt and lead to dramatic surges in total current from 1 MA to over 5 MA in less than 20 minutes. The current surges occur predominantly on the dayside at high latitudes prior to any ring current or auroral expansions, indicating that neutral density upwelling is often driven independently of ring current or auroral zone intensifications. Rapid reconfigurations of the currents with IMF BY reversals within the sheath structures of coronal mass ejections (CMEs) are also common. This implies that convection of ionospheric density patches over the polar cap may be quite complex, particularly during the early phase of geomagnetic storms related to the CME sheath passage. The 3 September 2012 storm exhibited intense driving with classic quasi-stable Region 1 and 2 currents spanning 55 to 70 degrees magnetic latitude for over 10 hours at the beginning of the day, corresponding to stable southward IMF prior to shock arrival at noon on that day. The shock arrival and IMF southward intensification led to further expansion of the currents below 50 degrees magnetic latitude and to episodic surges in currents on the nightside, which is unique to storms. The resulting current structure showed multiple large-scale alternations in downward-upward-downward-upward direction that often occurs during intense, sustained driving during strong storms.

  9. Multifrequency time-harmonic elastography for the measurement of liver viscoelasticity in large tissue windows.

    PubMed

    Tzschätzsch, Heiko; Ipek-Ugay, Selcan; Trong, Manh Nguyen; Guo, Jing; Eggers, Jonathan; Gentz, Enno; Fischer, Thomas; Schultz, Michael; Braun, Jürgen; Sack, Ingolf

    2015-03-01

    Elastography of the liver for the non-invasive diagnosis of hepatic fibrosis is an established method. However, investigations of obese patients or patients with ascites are often limited by small and superficial elastographic windows. Therefore, multifrequency time-harmonic elastography (THE) based on time-resolved A-line ultrasound has recently been developed for measuring liver viscoelasticity in wide soft tissue windows and at greater depths. In this study, THE was integrated into a clinical B-mode scanner connected to a dedicated actuator bed driven by superimposed vibrations of 30- to 60-Hz frequencies. The resulting shear waves in the liver were captured along multiple profiles 7 to 14 cm in width and automatically processed for reconstruction of mean efficient shear wave speed and shear wave dispersion slope. This new modality was tested in healthy volunteers and 22 patients with clinically proven cirrhosis. Patients could be separated from controls by higher shear wave speeds (3.11 ± 0.64 m/s, 2.14-4.81 m/s, vs. 1.74 ± 0.10 m/s, 1.60-1.91 m/s) without significant degradation of data by high body mass index or ascites. Furthermore, the wave speed dispersion slope was significantly (p = 0.0025) lower in controls (5.2 ± 1.8 m/s/kHz) than in patients (39.1 ± 32.2 m/s/kHz). In conclusion, THE is useful for the diagnosis of cirrhosis in large tissue windows.

  10. Track distortion in the Large prototype of a Time Projection Chamber for the International Linear Collider

    NASA Astrophysics Data System (ADS)

    Sankar Bhattacharya, Deb; Bhattacharya, Purba; Mukhopadhyay, Supratik; Majumdar, Nayana; Bhattacharya, Sudeb; Sarkar, Sandip; Colas, Paul; Attie, David; Ganjour, Serguei; Bhattacharya, Aparajita

    2016-10-01

    A Micromegas (MM) based Time Projection Chamber (TPC) can meet the ILC requirements of continuous 3-D tracking, excellent spatial resolution and efficient pattern recognition. Seven MM modules which are commissioned on the end-plate of a Large Prototype TPC (LPTPC) at DESY, have been tested with a 5 GeV electron beam, under a 1 T magnetic field. Due to the grounded peripheral frame of the MM modules, at short drift, the electric field near the detector edge remain no longer parallel to the TPC axis. This causes signal loss along the boundaries of the MM modules as well as distortion in the reconstructed track. In presence of magnetic field, the distorted electric field introduces E×B effect. A detailed numerical study has been accomplished to understand the features of this distortion. Four Micromegas modules have been simulated resembling the experimental setup. The field lines, drift line of electrons considering diffusion in gas, nature of track distortion, residuals are numerically calculated in presence and in absence of magnetic field. The E×B effect has been simulated as well. Simulated results follow the experimental observations.

  11. "Tools For Analysis and Visualization of Large Time- Varying CFD Data Sets"

    NASA Technical Reports Server (NTRS)

    Wilhelms, Jane; vanGelder, Allen

    1999-01-01

    During the four years of this grant (including the one year extension), we have explored many aspects of the visualization of large CFD (Computational Fluid Dynamics) datasets. These have included new direct volume rendering approaches, hierarchical methods, volume decimation, error metrics, parallelization, hardware texture mapping, and methods for analyzing and comparing images. First, we implemented an extremely general direct volume rendering approach that can be used to render rectilinear, curvilinear, or tetrahedral grids, including overlapping multiple zone grids, and time-varying grids. Next, we developed techniques for associating the sample data with a k-d tree, a simple hierarchial data model to approximate samples in the regions covered by each node of the tree, and an error metric for the accuracy of the model. We also explored a new method for determining the accuracy of approximate models based on the light field method described at ACM SIGGRAPH (Association for Computing Machinery Special Interest Group on Computer Graphics) '96. In our initial implementation, we automatically image the volume from 32 approximately evenly distributed positions on the surface of an enclosing tessellated sphere. We then calculate differences between these images under different conditions of volume approximation or decimation.

  12. Data transfer over the wide area network with a large round trip time

    NASA Astrophysics Data System (ADS)

    Matsunaga, H.; Isobe, T.; Mashimo, T.; Sakamoto, H.; Ueda, I.

    2010-04-01

    A Tier-2 regional center is running at the University of Tokyo in Japan. This center receives a large amount of data of the ATLAS experiment from the Tier-1 center in France. Although the link between the two centers has 10Gbps bandwidth, it is not a dedicated link but is shared with other traffic, and the round trip time is 290ms. It is not easy to exploit the available bandwidth for such a link, so-called long fat network. We performed data transfer tests by using GridFTP in various combinations of the parameters, such as the number of parallel streams and the TCP window size. In addition, we have gained experience of the actual data transfer in our production system where the Disk Pool Manager (DPM) is used as the Storage Element and the data transfer is controlled by the File Transfer Service (FTS). We report results of the tests and the daily activity, and discuss the improvement of the data transfer throughput.

  13. The Large-Area Time-Of-Flight (TOF) Upgrade for the STAR Detector

    NASA Astrophysics Data System (ADS)

    Llope, W. J.

    2009-03-01

    The STAR experiment at RHIC concentrates on the tracking of charged hadrons via ionization in gas- and silicon-based detectors, and the detection of electrons and photons via calorimetry, in a wide and azimuthally complete acceptance that's unique at RHIC. STAR's ability to directly identify the tracked charged hadrons is however limited to low momenta. Approximately half of the charged particles in the event at higher momenta cannot be directly identified, which hampers the physics reach of STAR in a number of key areas. To address this blind spot, STAR is presently constructing a large-area (˜50 m2) Time-Of-Flight (TOF) system. This system is based on Multi-gap Resistive Plate Chambers (MRPCs). Prototype TOF systems based on this technology were operated in STAR during RHIC Runs 3 through 6, and the first 5 final-system trays were operated in the recent RHIC Run 8. A new "start detector" for this system has also been constructed and operated in STAR. The performance of these detectors in STAR, and an update on the status of the construction of the full system, is discussed.

  14. A time and space correlated turbulence synthesis method for Large Eddy Simulations

    NASA Astrophysics Data System (ADS)

    Castro, Hugo G.; Paz, Rodrigo R.

    2013-02-01

    In the present work the problem of generating synthesized turbulence at inflow boundaries of the simulation domain is addressed in the context of the Large Eddy Simulation (LES) method. To represent adequately certain statistical properties of a turbulent process, we propose a synthesized turbulence method which is based on previous works (Huang et al., 2010; Smirnov et al., 2001) [15,28]. For this purpose, time and space correlations are introduced strictly in the mathematical formulation of the synthetic turbulence inflow data. It is demonstrated that the proposed approach inherits the properties of the methods on which it is based while presents some particular advantages as well. The strategy of imposing conditions on the inlet velocity field through turbulence synthesis is implemented in the parallel multiphysics code called PETSc-FEM (http://www.cimec.org.ar/petscfem) primarily targeted to calculations throughout finite elements on general unstructured 2D and 3D grids. We present several numerical tests in order to validate and evaluate the method describing the dynamic phenomena that take place in “real-life” problems, such as a swirling turbulent flow inside a diffuser and the airflow around a vehicle model inside a wind tunnel at high Reynolds number.

  15. Long-time analytic approximation of large stochastic oscillators: Simulation, analysis and inference

    PubMed Central

    2017-01-01

    In order to analyse large complex stochastic dynamical models such as those studied in systems biology there is currently a great need for both analytical tools and also algorithms for accurate and fast simulation and estimation. We present a new stochastic approximation of biological oscillators that addresses these needs. Our method, called phase-corrected LNA (pcLNA) overcomes the main limitations of the standard Linear Noise Approximation (LNA) to remain uniformly accurate for long times, still maintaining the speed and analytically tractability of the LNA. As part of this, we develop analytical expressions for key probability distributions and associated quantities, such as the Fisher Information Matrix and Kullback-Leibler divergence and we introduce a new approach to system-global sensitivity analysis. We also present algorithms for statistical inference and for long-term simulation of oscillating systems that are shown to be as accurate but much faster than leaping algorithms and algorithms for integration of diffusion equations. Stochastic versions of published models of the circadian clock and NF-κB system are used to illustrate our results. PMID:28742083

  16. Long-time analytic approximation of large stochastic oscillators: Simulation, analysis and inference.

    PubMed

    Minas, Giorgos; Rand, David A

    2017-07-01

    In order to analyse large complex stochastic dynamical models such as those studied in systems biology there is currently a great need for both analytical tools and also algorithms for accurate and fast simulation and estimation. We present a new stochastic approximation of biological oscillators that addresses these needs. Our method, called phase-corrected LNA (pcLNA) overcomes the main limitations of the standard Linear Noise Approximation (LNA) to remain uniformly accurate for long times, still maintaining the speed and analytically tractability of the LNA. As part of this, we develop analytical expressions for key probability distributions and associated quantities, such as the Fisher Information Matrix and Kullback-Leibler divergence and we introduce a new approach to system-global sensitivity analysis. We also present algorithms for statistical inference and for long-term simulation of oscillating systems that are shown to be as accurate but much faster than leaping algorithms and algorithms for integration of diffusion equations. Stochastic versions of published models of the circadian clock and NF-κB system are used to illustrate our results.

  17. Using PLATO IV.

    ERIC Educational Resources Information Center

    Meller, David V.

    This beginning reference manual describes PLATO IV hardware for prospective users and provides an introduction to PLATO for new authors. The PLATO terminal is described in detail in Chapter 1. Chapter 2 provides a block diagram of the PLATO IV system. Procedures for getting on line are described in Chapter 3, and Chapter 4 provides references to…

  18. Identification of genetic variants associated with maize flowering time using an extremely large multi-genetic background population

    USDA-ARS?s Scientific Manuscript database

    Flowering time is one of the major adaptive traits in domestication of maize and an important selection criterion in breeding. To detect more maize flowering time variants we evaluated flowering time traits using an extremely large multi- genetic background population that contained more than 8000 l...

  19. Comparing two fish sampling standards over time: largely congruent results but with caveats

    USGS Publications Warehouse

    Yule, Daniel L.; Evrard, Lori M.; Cachera, Sébastien; Colon, Michel; Guillard, Jean

    2013-01-01

    1. We sampled Lake Bourget (surface area = 44 km2) using CEN standard gillnet and provisional standard acoustic survey methods over 3 years (2005, 2010 and 2011) as the fish community responded to re-oligotrophication. A total of 16 species were caught in benthic gillnets and three species in pelagic gillnets. 2. Lake Bourget results were consistent with a recent study (Emmrich et al., Freshwater Biology, 57, 2012, 2436) showing strong correspondence between average biomass-per-unit-effort (BPUE) in standard benthic gillnets and average acoustic volume backscattering when smaller lakes (0.25–5.45 km2) were treated as sample units. 3. The BPUE of whitefish (Coregonus lavaretus), perch (Perca fluviatilis) and roach (Rutilus rutilus) measured by benthic gillnets all declined significantly with increasing bathymetric depth; 93% of nets set at depths >50 m caught zero fish. 4. Pelagic gillnetting indicated that small (20 m) increased significantly after 2005. 5. Both surveys showed whitefish biomass increased significantly during the study, but whitefish ≥25 cm were poorly represented in benthic gillnet catches. Contrary to the acoustic findings, the BPUE of perch and roach in benthic gillnets did not vary significantly over time. This metric is insensitive to changes in size structure in that a high catch of small fish and a low catch of large fish in different years can provide similar average BPUE estimates. 6. We examined correlations between BPUE in benthic gillnets and acoustic methods at fine spatial scales by averaging acoustic backscattering measurements encompassed by buffers of varying size (250–2000 m) around individual gillnets and by averaging samples collected from lake quadrants. Correlations at fines scales were generally poor, and only in 1 year was the quadrant correlation significant. The lack of correlation can be explained, in part, by the two gears sampling different components of the fish community. Conversely, in pelagic habitat, where the

  20. Preliminary Engineering Study of Long-Lead Time Equipment Required for Large Lightweight Mirror Manufacture

    DTIC Science & Technology

    1981-06-01

    numnber) Annealing Fusion Sealed Mirrors ULED Mirrors Boule Large Lightweight Mirror Core Low Expansion Glass Coremaker Mirror Blanks Forming Furnace...Experiments 34 4 10.6 Grinder Procurement 35 J 1 I GLOSSARY Alpha - Coef. of thermal expansion. Boule - The disc of glass formed in the furnace. Cell...turning over of large plates, cores or mirrors. Flowout - Method used to produce large diameter plates from small diameter boules. Glass - Used in the

  1. Did volcanic activity of the Emeishan large igneous province expand in Wuchiapingian times?

    NASA Astrophysics Data System (ADS)

    Bagherpour, Borhan; Bucher, Hugo; Yuan, Dong-Xun; Shen, Shu-zhong; Leu, Marc; Zhang, Chao

    2017-04-01

    Emplacement of the Emeishan Large Igneous Province (ELIP) in the Capitanian (Middle Permian) is associated with several environmental changes (e.g. facies change, carbon cycle perturbation and temperature rise) across the Guadalupian-Lopingian (G-L) interval in South China. However, most of the reported changes are within the Capitanian stage or close to the G-L boundary. Here, we report an episode of drastic environmental changes from the Pingtang syncline (S. Guizhou) that is similar with the previously known ones but which is significantly younger. The studied section represents a protracted and stepwise facies change from a benthos rich, thick-bedded and light grey shallow water limestone (Unit A) to a 30 m-thick unit with thin-bedded dark (OM-rich) radiolarian-spiculitic facies (Unit B). The latter is overlain by an 8 m-thick unit of volcaniclastic sandstone and silts defining a succession of decimetric, cyclic and thinning upward layers (Unit C). The base of the overlying medium-bedded limestone unit (Unit D) contain radiolarian and sponge spicules whose abundance progressively decrease up section with a progressive replacement by abundant benthic faunas concomitant with the transition to thick bedded limestone. A total of five conodont index species (assigned to Clarkina) of early Wuchiapingian age were recognized from Unit A and Unit B. The observed facies transition from Unit A to Unit B indicates a drastic drowning event. Unit C represents a distal turbiditic succession and the overlying Unit D shows an upward shallowing trend back to the initial shallow marine condition. Compilation of sedimentary records across G-L in South China reveals that such drowning events tend to cluster within three discrete time intervals. The drowning events may or may not end with deposition of either volcanics or volcaniclastics. Two first clusters display drowning events overlain by ELIP volcanic rocks or volcaniclastics of ELIP origin and are of Capitanian age. Only the

  2. The Potential of Time Series Based Earth Observation for the Monitoring of Large River Deltas

    NASA Astrophysics Data System (ADS)

    Kuenzer, C.; Leinenkugel, P.; Huth, J.; Ottinger, M.; Renaud, F.; Foufoula-Georgiou, E.; Vo Khac, T.; Trinh Thi, L.; Dech, S.; Koch, P.; Le Tissier, M.

    2015-12-01

    Although river deltas only contribute 5% to the overall land surface, nearly six hundred million people live in these complex social-ecological environments, which combine a variety of appealing locational advantages. In many countries deltas provide the major national contribution to agricultural and industrial production. At the same time these already very dynamic environments are exposed to a variety of threats, including the disturbance and replacement of valuable ecosystems, increasing water, soil, and air pollution, human induced land subsidence, sea level rise, as well upstream developments impacting water and sediment supplies. A constant monitoring of delta systems is thus of utmost relevance for understanding past and current land surface change and anticipating possible future developments. We present the potential of Earth Observation based analyses and derived novel information products that can play a key role in this context. Along with the current trend of opening up numerous satellite data archives go increasing capabilities to explore big data. Whereas in past decades remote sensing data were analysed based on the spectral-reflectance-defined 'finger print' of individual surfaces, we mainly exploit the 'temporal fingerprints' of our land surface in novel pathways of data analyses at differing spatial-, and temporally-dense scales. Following our results on an Earth Observation based characterization of large deltas globally, we present in depth results from the Mekong Delta in Vietnam, the Yellow River Delta in China, the Niger Delta in Nigeria, as well as additional deltas, focussing on the assessment of river delta flood and inundation dynamics, river delta coastline dynamics, delta morphology dynamics including the quantification of erosion and accretion processes, river delta land use change and trends, as well as the monitoring of compliance to environmental regulations.

  3. Across space and time: social responses to large-scale biophysical systems.

    PubMed

    MacMynowski, Dena P

    2007-06-01

    The conceptual rubric of ecosystem management has been widely discussed and deliberated in conservation biology, environmental policy, and land/resource management. In this paper, I argue that two critical aspects of the ecosystem management concept require greater attention in policy and practice. First, although emphasis has been placed on the "space" of systems, the "time" -- or rates of change -- associated with biophysical and social systems has received much less consideration. Second, discussions of ecosystem management have often neglected the temporal disconnects between changes in biophysical systems and the response of social systems to management issues and challenges. The empirical basis of these points is a case study of the "Crown of the Continent Ecosystem," an international transboundary area of the Rocky Mountains that surrounds Glacier National Park (USA) and Waterton Lakes National Park (Canada). This project assessed the experiences and perspectives of 1) middle- and upper-level government managers responsible for interjurisdictional cooperation, and 2) environmental nongovernment organizations with an international focus. I identify and describe 10 key challenges to increasing the extent and intensity of transboundary cooperation in land/resource management policy and practice. These issues are discussed in terms of their political, institutional, cultural, information-based, and perceptual elements. Analytic techniques include a combination of environmental history, semistructured interviews with 48 actors, and text analysis in a systematic qualitative framework. The central conclusion of this work is that the rates of response of human social systems must be better integrated with the rates of ecological change. This challenge is equal to or greater than the well-recognized need to adapt the spatial scale of human institutions to large-scale ecosystem processes and transboundary wildlife.

  4. How the timing of weather events influences early development in a large mammal.

    PubMed

    Hendrichsen, D K; Tyler, N J C

    2014-07-01

    Capturing components of the weather that drive environment-animal interactions is a perennial problem in ecology. Identifying biologically significant elements of weather conditions in sensible statistics suitable for analysis of life history variation and population dynamics is central. Meteorological variables such as temperature, precipitation, and wind modulate rates of heat loss in animals, but analysis of their effects on endothermic species is complicated by the fact that their influence on energy balance is not invariably linear, even across the thermoneutral range. Rather, the thermal load imposed by a given set of weather conditions is a function of organisms' metabolic requirement, which, crucially, may vary spontaneously both seasonally and across different life phases. We propose that the endogenous component of variation in metabolic demand introduces a temporal dimension and that, as a consequence, the specific effect of meteorological variables on energy balance and attendant life history parameters is a function of the timing of weather events with respect to the organism's metabolic rhythm(s). To test this, we examined how a spontaneous increase in metabolic demand influenced the effect of weather on early development in a large mammal. Specifically, we examined interaction between the exponential rise in the energy requirements of pregnancy and depth of snow, which restricts dams' access to forage, on the body mass of reindeer calves (Rangifer tarandus) at weaning. As expected, we detected a significant temporal component: the specific negative effect of snow on weaning mass was not constant, but increased across pregnancy. The life history response was therefore better predicted by interaction between the magnitude and the timing of weather events than by their magnitude alone. To our knowledge, this is the first demonstration of the influence of an endogenous metabolic dynamic on the impact of weather on a life history trait in a free

  5. Tools for Analysis and Visualization of Large Time-Varying CFD Data Sets

    NASA Technical Reports Server (NTRS)

    Wilhelms, Jane; VanGelder, Allen

    1997-01-01

    In the second year, we continued to built upon and improve our scanline-based direct volume renderer that we developed in the first year of this grant. This extremely general rendering approach can handle regular or irregular grids, including overlapping multiple grids, and polygon mesh surfaces. It runs in parallel on multi-processors. It can also be used in conjunction with a k-d tree hierarchy, where approximate models and error terms are stored in the nodes of the tree, and approximate fast renderings can be created. We have extended our software to handle time-varying data where the data changes but the grid does not. We are now working on extending it to handle more general time-varying data. We have also developed a new extension of our direct volume renderer that uses automatic decimation of the 3D grid, as opposed to an explicit hierarchy. We explored this alternative approach as being more appropriate for very large data sets, where the extra expense of a tree may be unacceptable. We also describe a new approach to direct volume rendering using hardware 3D textures and incorporates lighting effects. Volume rendering using hardware 3D textures is extremely fast, and machines capable of using this technique are becoming more moderately priced. While this technique, at present, is limited to use with regular grids, we are pursuing possible algorithms extending the approach to more general grid types. We have also begun to explore a new method for determining the accuracy of approximate models based on the light field method described at ACM SIGGRAPH '96. In our initial implementation, we automatically image the volume from 32 equi-distant positions on the surface of an enclosing tessellated sphere. We then calculate differences between these images under different conditions of volume approximation or decimation. We are studying whether this will give a quantitative measure of the effects of approximation. We have created new tools for exploring the

  6. The Effect of Access Time on Online Quiz Performance in Large Biology Lecture Courses

    ERIC Educational Resources Information Center

    Metz, Anneke M.

    2008-01-01

    To better understand the dynamics of online student test taking, including the likelihood of cheating by large numbers of students, we examined test-taking patterns and outcomes of weekly online quizzes in two large undergraduate biology lecture courses. Students taking a quiz late in a 1-3-day quiz access period performed 10-15% worse on quizzes…

  7. Prospective Evaluation of the Safety and Efficacy of a 1060-nm Large Spot Size, Vacuum-Assisted Hair Removal Diode Laser System in Asian/Pacific Fitzpatrick's Skin Types IV-V Patients.

    PubMed

    Tahiliani, Sushil T; Tahiliani, Harsh S

    2016-11-01

    Laser-based photoepilation of dark skin types demands a delicate combination of appropriate light wavelengths and spot size to achieve optimal epidermal-to-follicular energy absorption ratios. This prospective study assessed the axillary, arm, thigh, and back hair clearing ef cacy of the LightSheer In nity 1060 nm diode laser in 10 Fitzpatrick skin type IV-V patients. Each area was treated up to ve times, at 4-6-week intervals, after which immediate skin responses and adverse events were recorded. Hair count, color and coarseness were assessed before each treatment session, as well as 1, 3, and 6 months following the last session. Both patients and the treating physician rated the degree of improvement with time, and patients also ranked their satisfaction with the treatment outcome. Percent hair reduction from baseline gradually increased with treatment and peaked at 74.6%, 68.4%, and 65.7% for axillary, arm and thigh regions, respectively, 6 months following the last treatment session. Baseline hair growth patterns precluded effective selection of a representative area for hair counting. Patients satisfaction was consistently higher for axillary hair clearance rates, followed by thigh and arm responses. Throughout the follow-up period, the investigator rated 50-67% of the treated axillae as presenting "good" or "very good" hair clearance, and provided similar ratings for 67% of the treated thigh regions at both the 1 and 6 month follow-up sessions. Immediate responses to treatment were mild to moderate and short-lived and no incidents of brosis or scarring were reported. Taken together, the LightSheer In nity 1060 HS Handpiece provided for an ideal ef cacy-safety balance in treating dark-skinned patients, providing for long-term hair clearance with minimal downtime. J Drugs Dermatol. 2016;15(11):1427-1434.

  8. IV treatment at home

    MedlinePlus

    ... venous catheter - home; Port - home; PICC line - home; Infusion therapy - home; Home health care - IV treatment ... is given quickly, all at once. A slow infusion, which means the medicine is given slowly over ...

  9. Note: A large open ratio, time, and position sensitive detector for time of flight measurements in UHV.

    PubMed

    Lupone, S; Damoy, S; Husseen, A; Briand, N; Debiossac, M; Tall, S; Roncin, P

    2015-12-01

    We report on the construction of an UHV compatible 40 mm active diameter detector based on micro channel plates and assembled directly on the feed-throughs of a DN63CF flange. It is based on the charge division technique and uses a standard 2 inch Si wafer as a collector. The front end electronic is placed directly on the air side of the flange allowing excellent immunity to noise and a very good timing signal with reduced ringing. The important aberrations are corrected empirically providing an absolute positioning accuracy of 500 μm while a 150 μm resolution is measured in the center.

  10. Note: A large open ratio, time, and position sensitive detector for time of flight measurements in UHV

    SciTech Connect

    Lupone, S.; Damoy, S.; Husseen, A.; Briand, N.; Debiossac, M.; Tall, S.; Roncin, P.

    2015-12-15

    We report on the construction of an UHV compatible 40 mm active diameter detector based on micro channel plates and assembled directly on the feed-throughs of a DN63CF flange. It is based on the charge division technique and uses a standard 2 inch Si wafer as a collector. The front end electronic is placed directly on the air side of the flange allowing excellent immunity to noise and a very good timing signal with reduced ringing. The important aberrations are corrected empirically providing an absolute positioning accuracy of 500 μm while a 150 μm resolution is measured in the center.

  11. GCF Mark IV development

    NASA Technical Reports Server (NTRS)

    Mortensen, L. O.

    1982-01-01

    The Mark IV ground communication facility (GCF) as it is implemented to support the network consolidation program is reviewed. Changes in the GCF are made in the area of increased capacity. Common carrier circuits are the medium for data transfer. The message multiplexing in the Mark IV era differs from the Mark III era, in that all multiplexing is done in a GCF computer under GCF software control, which is similar to the multiplexing currently done in the high speed data subsystem.

  12. Students' Understanding of Large Numbers as a Key Factor in Their Understanding of Geologic Time

    ERIC Educational Resources Information Center

    Cheek, Kim A.

    2012-01-01

    An understanding of geologic time is comprised of 2 facets. Events in Earth's history can be placed in relative and absolute temporal succession on a vast timescale. Rates of geologic processes vary widely, and some occur over time periods well outside human experience. Several factors likely contribute to an understanding of geologic time, one of…

  13. Finite-time and finite-size scalings in the evaluation of large-deviation functions: Numerical approach in continuous time

    NASA Astrophysics Data System (ADS)

    Guevara Hidalgo, Esteban; Nemoto, Takahiro; Lecomte, Vivien

    2017-06-01

    Rare trajectories of stochastic systems are important to understand because of their potential impact. However, their properties are by definition difficult to sample directly. Population dynamics provides a numerical tool allowing their study, by means of simulating a large number of copies of the system, which are subjected to selection rules that favor the rare trajectories of interest. Such algorithms are plagued by finite simulation time and finite population size, effects that can render their use delicate. In this paper, we present a numerical approach which uses the finite-time and finite-size scalings of estimators of the large deviation functions associated to the distribution of rare trajectories. The method we propose allows one to extract the infinite-time and infinite-size limit of these estimators, which—as shown on the contact process—provides a significant improvement of the large deviation function estimators compared to the standard one.

  14. Tunable mechanical monolithic sensors for real-time broadband monitoring of large civil infrastructures

    NASA Astrophysics Data System (ADS)

    Barone, F.; Giordano, G.

    2016-10-01

    This paper describes the application of the monolithic UNISA Folded Pendulum, optimized as inertial sensor (seismometer) for low frequency characterization of sites (including underground sites) and structures (e.g. buildings, bridges, historical monuments), but, in general, for applications requiring large band low-frequency performances coupled with high sensitivities. The main characteristics of this class of sensors are high sensitivity, large measurement band, compactness, lightness, scalability, tunability of the resonance frequency, low thermal noise and very good immunity to environmental noises. The horizontal and vertical versions of folded pendulum allow an effective state-of-the-art mechanical implementation of triaxial sensors, configurable both as seismometer and/or as accelerometer.

  15. Visual analytics techniques for large multi-attribute time series data

    NASA Astrophysics Data System (ADS)

    Hao, Ming C.; Dayal, Umeshwar; Keim, Daniel A.

    2008-01-01

    Time series data commonly occur when variables are monitored over time. Many real-world applications involve the comparison of long time series across multiple variables (multi-attributes). Often business people want to compare this year's monthly sales with last year's sales to make decisions. Data warehouse administrators (DBAs) want to know their daily data loading job performance. DBAs need to detect the outliers early enough to act upon them. In this paper, two new visual analytic techniques are introduced: The color cell-based Visual Time Series Line Charts and Maps highlight significant changes over time in a long time series data and the new Visual Content Query facilitates finding the contents and histories of interesting patterns and anomalies, which leads to root cause identification. We have applied both methods to two real-world applications to mine enterprise data warehouse and customer credit card fraud data to illustrate the wide applicability and usefulness of these techniques.

  16. Synthesis procedure for linear time-varying feedback systems with large parameter ignorance

    NASA Technical Reports Server (NTRS)

    Mcdonald, T. E., Jr.

    1972-01-01

    The development of synthesis procedures for linear time-varying feedback systems is considered. It is assumed that the plant can be described by linear differential equations with time-varying coefficients; however, ignorance is associated with the plant in that only the range of the time-variations are known instead of exact functional relationships. As a result of this plant ignorance the use of time-varying compensation is ineffective so that only time-invariant compensation is employed. In addition, there is a noise source at the plant output which feeds noise through the feedback elements to the plant input. Because of this noise source the gain of the feedback elements must be as small as possible. No attempt is made to develop a stability criterion for time-varying systems in this work.

  17. Doin' Time in College: An Ethnographic Study of Power and Motivation in a Large Lecture Class.

    ERIC Educational Resources Information Center

    Campbell, Cheri Ellis

    An ethnographic study examined instructor uses of control, immediacy, and affinity-seeking behaviors in a large college lecture class. A class of 140 college sophomores was observed for 10 weeks, in an attempt to understand in a situational and non-quantitative manner, what instructor behaviors motivate students toward cognitive and affective…

  18. Real-Time Large Scale 3d Reconstruction by Fusing Kinect and Imu Data

    NASA Astrophysics Data System (ADS)

    Huai, J.; Zhang, Y.; Yilmaz, A.

    2015-08-01

    Kinect-style RGB-D cameras have been used to build large scale dense 3D maps for indoor environments. These maps can serve many purposes such as robot navigation, and augmented reality. However, to generate dense 3D maps of large scale environments is still very challenging. In this paper, we present a mapping system for 3D reconstruction that fuses measurements from a Kinect and an inertial measurement unit (IMU) to estimate motion. Our major achievements include: (i) Large scale consistent 3D reconstruction is realized by volume shifting and loop closure; (ii) The coarse-to-fine iterative closest point (ICP) algorithm, the SIFT odometry, and IMU odometry are combined to robustly and precisely estimate pose. In particular, ICP runs routinely to track the Kinect motion. If ICP fails in planar areas, the SIFT odometry provides incremental motion estimate. If both ICP and the SIFT odometry fail, e.g., upon abrupt motion or inadequate features, the incremental motion is estimated by the IMU. Additionally, the IMU also observes the roll and pitch angles which can reduce long-term drift of the sensor assembly. In experiments on a consumer laptop, our system estimates motion at 8Hz on average while integrating color images to the local map and saving volumes of meshes concurrently. Moreover, it is immune to tracking failures, and has smaller drift than the state-of-the-art systems in large scale reconstruction.

  19. Precipitation-snowmelt timing and snowmelt augmentation of large peak flow events, western Cascades, Oregon

    Treesearch

    Keith Jennings; Julia A. Jones

    2015-01-01

    This study tested multiple hydrologic mechanisms to explain snowpack dynamics in extreme rain-on-snow floods, which occur widely in the temperate and polar regions. We examined 26, 10 day large storm events over the period 1992–2012 in the H.J. Andrews Experimental Forest in western Oregon, using statistical analyses (regression, ANOVA, and wavelet coherence) of hourly...

  20. Underutilization of IV nitrates in the treatment of acute heart failure.

    PubMed

    Mohan, Mohapradeep; Hawkey, Sean; Baig, Fatima; Choy, Anna Maria; Lang, Chim C

    2015-08-01

    Acute heart failure (AHF) is a growing public health concern with high inhospital mortality and costs. Clinical practice guidelines, underpinned by positive randomized controlled trials, recommend the early use of intravenous (IV) nitrates in the treatment of AHF. However, the "real-world" usage of IV nitrates has not been clearly defined. The objective of this study was to examine the use of IV nitrates in the treatment of AHF as recommended by clinical practice guidelines. A case-record analysis was conducted of all admissions with AHF at a large teaching hospital. Of the 81 AHF patients (mean age 77 ± 11, mean SBP 130 ± 27 mmHg) enrolled for this analysis, only 5 (6%) received IV nitrates at the time of AHF admission. Forty (49%, mean age 77 ± 11, mean SBP 131 ± 27 mmHg) of these 81 patients met the guideline criteria for suitability for IV nitrates and only 5 (12%) of these received them during this admission. Patients who received IV nitrates were more likely to have higher blood pressure and all had myocardial ischemia as a precipitant. Seventy-five (93%) of the total population received loop diuretics on admission. Overall, this study shows that loop diuretics remain the first-line therapy in AHF with little use of IV nitrates, despite recommendations from clinical practice guidelines.

  1. On the existence of oscillations in solar filaments observed in H alpha and C IV lines

    NASA Technical Reports Server (NTRS)

    Schmieder, B.; Malherbe, J. M.; Mein, P.; Tandberg-Hanssen, E.

    1986-01-01

    Time sequence observations of filaments in both the H alpha line and the 1548 A C IV line were analyzed with the Fourier transform technique in the frequency range (1 - 10 mHz). No oscillation is detected in filaments except at the footpoints where a steady velocity gradient is large. The energy is probably due to convective motions rather than pressure oscillations.

  2. Relating the large-scale structure of time series and visibility networks.

    PubMed

    Rodríguez, Miguel A

    2017-06-01

    The structure of time series is usually characterized by means of correlations. A new proposal based on visibility networks has been considered recently. Visibility networks are complex networks mapped from surfaces or time series using visibility properties. The structures of time series and visibility networks are closely related, as shown by means of fractional time series in recent works. In these works, a simple relationship between the Hurst exponent H of fractional time series and the exponent of the distribution of edges γ of the corresponding visibility network, which exhibits a power law, is shown. To check and generalize these results, in this paper we delve into this idea of connected structures by defining both structures more properly. In addition to the exponents used before, H and γ, which take into account local properties, we consider two more exponents that, as we will show, characterize global properties. These are the exponent α for time series, which gives the scaling of the variance with the size as var∼T^{2α}, and the exponent κ of their corresponding network, which gives the scaling of the averaged maximum of the number of edges, 〈k_{M}〉∼N^{κ}. With this representation, a more precise connection between the structures of general time series and their associated visibility network is achieved. Similarities and differences are more clearly established, and new scaling forms of complex networks appear in agreement with their respective classes of time series.

  3. Hard X-ray time profiles and acceleration processes in large solar flares

    NASA Technical Reports Server (NTRS)

    Bai, T.; Ramaty, R.

    1979-01-01

    The hard X-ray time profiles of the (1972) August 4 and 7 flares are investigated, taking into account a comparison of the time profiles of different energy channels. It is shown that for these flares the temporal features of the intensity profiles of higher energy channels are delayed with respect to those of channel 1. The delay time gradually increases to approximately 5 sec as the channel number increases from 1 to 5, and it jumps to approximately 15 sec for channels 6 and 7. A description is presented of a model in which the delay and other characteristics of the observed time profiles in channels 1-5 are self-consistently explained by the increase of the electron energy loss time with electron energy.

  4. Dwell time algorithm for multi-mode optimization in manufacturing large optical mirrors

    NASA Astrophysics Data System (ADS)

    Liu, Zhenyu

    2014-08-01

    CCOS (Computer Controlled Optical Surfacing) is one of the most important method to manufacture optical surface. By controlling the dwell time of a polishing tool on the mirror we can get the desired material removal. As the optical surface becoming larger, traditional CCOS method can't meet the demand that manufacturing the mirror in higher efficiency and precision. This paper presents a new method using multi-mode optimization. By calculate the dwell time map of different tool in one optimization cycle, the larger tool and the small one have complementary advantages and obtain a global optimization for multi tool and multi-processing cycles. To calculate the dwell time of different tool at the same time we use multi-mode dwell time algorithm that based on matrix calculation. With this algorithm we did simulation experiment, the result shows using multi-mode optimization algorithm can improve the efficiency maintaining good precision.

  5. Novel large format sealed tube microchannel plate detectors for Cherenkov timing and imaging

    NASA Astrophysics Data System (ADS)

    Siegmund, O. H. W.; McPhate, J. B.; Vallerga, J. V.; Tremsin, A. S.; Jelinsky, S. R.; Frisch, H. J.; Lappd Collaboration

    2011-05-01

    Large area (20×20 cm 2) sealed tube detectors using novel borosilicate glass microchannel plates, with bialkali photocathodes and strip-line readouts are being developed for Cherenkov light detection. Designs based on conventional sealed tubes with alumina brazed body construction and hot indium seals have been developed. Borosilicate glass substrates with 20 and 40 μm holes have been processed using atomic layer deposition to produce functional microchannel plates. Initial results for these in a 33 mm format show gain, imaging performance, pulse shape and lifetime characteristics that are similar to standard glass microchannel plates. Large area (20×20 cm 2) borosilicate glass substrates with 20 μm pores have also been made.

  6. Time-varying gyrocompass alignment for fiber-optic-gyro inertial navigation system with large misalignment angle

    NASA Astrophysics Data System (ADS)

    Ben, Yueyang; Li, Qian; Zhang, Yi; Huo, Liang

    2014-09-01

    Conventional strapdown gyrocompass alignment methods are based on the assumption that the fiber-optic-gyro inertial navigation system has a small azimuth misalignment angle. A large azimuth misalignment angle would lead to an extension of the alignment duration. A time-varying gyrocompass alignment method to solve this problem is provided. An appropriate parameter setting is given for the gyrocompass alignment with a large misalignment angle. Also, a proper protocol for a parametric switch is derived. Simulation and trail results show that the proposed method has better alignment performance than conventional ones, as the system has large misalignment angles.

  7. T-Cube: A Data Structure for Fast Extraction of Time Series from Large Datasets

    DTIC Science & Technology

    2007-04-01

    patients, and so on. Computational efficiency of mining operations which one may want to apply to such data, as well as the efficiency of accessing ...data mining procedures executed against such databases require access to a large number of different projections of data, if they are to...illustrative examples can be found in [3]. There are different types of implementations of data cubes based on how counts are stored internally. Relational

  8. Design for the correction system of the real time nonuniformity of large area-array CCD image

    NASA Astrophysics Data System (ADS)

    Wang, Yan; Li, Chunmei; Lei, Ning

    2012-10-01

    With the robust thriving of aviation cameras and remote sensing technology, the linear-array CCD (charge-coupled device) and area CCD have developed toward large area CCD, which has a broad coverage and avoids the difficulty in jointing small area CCDs in addition to improving time resolution. However, due to the high amount of pixels and channels of large area CCD, photo-response non-uniformity (PRNU) is severe. In this paper, a real time non-uniformity correction system is introduced for a sort of large area full frame transfer CCD. First, the correction algorithm is elaborated according to CCD's working principle. Secondly, due to the high number of pixels and correction coefficient, ordinary chip memory cannot meet the requirement. The combination of external flash memory and DDR described in the paper satisfies large capacity memory and rapid real time correction. The methods and measurement steps for obtaining correction factors are provided simultaneously. At the end, an imaging test is made. The non-uniformity of the image is reduced to 0.38 % from the pre-correction 2.96 %, achieving an obvious reduction of non-uniformity. The result shows that the real time non-uniformity correction system can meet the demands of large area-array CCD.

  9. Relationship between leisure time screen activity and aggressive and violent behaviour in Iranian children and adolescents: the CASPIAN-IV Study.

    PubMed

    Kelishadi, Roya; Qorbani, Mostafa; Motlagh, Mohammad Esmaeil; Heshmat, Ramin; Ardalan, Gelayol; Jari, Mohsen

    2014-08-21

    Background: This study aimed to assess the relationship between leisure time spent watching television (TV) and at a computer and aggressive and violent behaviour in children and adolescents. Methods: In this nationwide study, 14,880 school students, aged 6-18 years, were selected by cluster and stratified multi-stage sampling method from 30 provinces in Iran. The World Health Organization Global School-based Health Survey questionnaire (WHO-GSHS) was used. Results: Overall, 13,486 children and adolescents (50·8% boys, 75·6% urban residents) completed the study (participation rate 90·6%). The risk of physical fighting and quarrels increased by 29% (OR 1·29, 95% CI 1·19-1·40) with watching TV for >2 hr/day, by 38% (OR 1·38, 95% CI 1·21-1·57) with leisure time computer work of >2 hr/day, and by 42% (OR 1·42, 95% CI 1·28-1·58) with the total screen time of >2 hr/day. Watching TV or leisure time spent on a computer or total screen time of >2 hr/day increased the risk of bullying by 30% (OR 1·30, 95% CI 1·18-1·43), 57% (1·57, 95% CI 1·34-1·85) and 62% (OR 1·62, 95% CI 1·43-1·83). Spending >2 hr/day watching TV and total screen time increased the risk of being bullied by 12% (OR 1·12, 95% CI 1·02-1·22) and 15% (OR 1·15, 95% CI 1·02-1·28), respectively. This relationship was not statistically significant for leisure time spent on a computer (OR 1·10, 95% CI 0·9-1·27). Conclusions: Prolonged leisure time spent on screen activities is associated with violent and aggressive behaviour in children and adolescents. In addition to the duration of screen time, the association is likely to be explained also by the media content.

  10. Estimate interaction timing in a large volume HgI2 detector using cathode pulse waveforms

    PubMed Central

    Meng, L.J.; He, Z.

    2016-01-01

    This paper presents experimental results on the timing resolution achieved with a 5 mm thick HgI2 detector. The timing information was derived based on the cathode pre-amplifier pulse waveform, measured using a digital oscilloscope. The times of interaction were estimated by fitting the measured pulse waveforms to pre-defined waveform models. With this approach, problems related to the conventional leading edge or constant fraction triggering, such as slow charge carrier mobility, pulse shape variation and depth-dependent detector response can be greatly reduced. As a result, we showed a 13 ns timing resolution measured using the 5 mm thick HgI2 detector and a BaF2 coincidence detector with 511 keV full energy events. In this paper, we discuss several waveform models and the results achieved using these models. PMID:28260824

  11. Patterns and Timing of Failure for Diffuse Large B-Cell Lymphoma After Initial Therapy in a Cohort Who Underwent Autologous Bone Marrow Transplantation for Relapse.

    PubMed

    Dhakal, Sughosh; Bates, James E; Casulo, Carla; Friedberg, Jonathan W; Becker, Michael W; Liesveld, Jane L; Constine, Louis S

    2016-10-01

    To evaluate the location and timing of initial recurrence in patients with diffuse large B-cell lymphoma (DLBCL) who subsequently underwent high-dose chemotherapy with autologous stem cell transplant (HDC/ASCT), to direct approaches for disease surveillance, elucidate the patterns of failure of contemporary treatment strategies, and guide adjuvant treatment decisions. We analyzed consecutive patients with DLBCL who underwent HDC/ASCT between May 1992 and March 2014 at our institution. Of the 187 evaluable patients, 8 had incomplete data, and 79 underwent HDC/ASCT as a component of initial treatment for de novo or refractory DLBCL and were excluded from further analysis. The median age was 50.8 years; the median time to relapse was 1.3 years. Patients were segregated according to the initial stage at diagnosis, with early stage (ES) defined as stage I/II and advanced stage (AS) defined as stage III/IV. In total, 40.4% of the ES and 75.5% of the AS patients relapsed in sites of initial disease; 68.4% of those with ES disease and 75.0% of those with AS disease relapsed in sites of initial disease only. Extranodal relapses were common (44.7% in ES and 35.9% in AS) and occurred in a variety of organs, although gastrointestinal tract/liver (n=12) was most frequent. Most patients with DLBCL who relapse and subsequently undergo HDC/ASCT initially recur in the previously involved disease site(s). Time to recurrence is brief, suggesting that frequency of screening is most justifiably greatest in the early posttherapy years. © 2016 Elsevier Inc. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. On the Computation of Space-Time Correlations by Large-Eddy Simulation

    NASA Technical Reports Server (NTRS)

    He, Guo-Wei; Wang, Meng; Lele, Sanjiva K.

    2003-01-01

    Numerical comparisons in decaying isotropic turbulence suggest that there exist discrepancies in time correlations evaluated by DNS and LES using eddy-viscosity-type SGS models. This is consistent with the previous observations in forced isotropic turbulence. Therefore, forcing is not the main cause of the discrepancies. Comparisons among different SGS models in the LES also indicate that the model choice affects the time correlations in the LES. The multi-scale LES method using the dynamic Smagorinsky model on the small scale equation is the most accurate of the all models, the classic Smagorinsky model is the least accurate and the dynamic Smagorinsky model and spectral eddy viscosity model give intermediate results with small differences. The generalized sweeping hypothesis implies that time correlations in decaying isotropic turbulence are mainly determined by the instantaneous energy spectra and sweeping velocities. The analysis based on the sweeping hypothesis explains the discrepancies in our numerical simulations: the LES overpredicts the decorrelation time scales because the sweeping velocities are smaller than the DNS values, and underpredicts the magnitudes of time correlations because the energy spectrum levels are lower than the DNS ones. Since the sweeping velocity is determined by the energy spectra, one concludes that an accurate prediction of the instantaneous energy spectra guarantees the accuracy of time correlations. An analytical expression of sound power spectra based on Lighthill's theory and the quasi-normal closure assumption suggests that the sound power spectra are sensitive to errors in time correlations. Small errors in time correlations can cause significant errors in the sound power spectra, which exhibit a sizable drop at moderate to high frequencies accompanied by a shift of the peaks to lower frequencies. Based on the above analysis, two possible ways to improve the acoustic power spectrum predictions can be considered. The first

  13. Radiation of de-excited electrons at large times in a strong electromagnetic plane wave

    SciTech Connect

    Kazinski, P.O.

    2013-12-15

    The late time asymptotics of the physical solutions to the Lorentz–Dirac equation in the electromagnetic external fields of simple configurations–the constant homogeneous field, the linearly polarized plane wave (in particular, the constant uniform crossed field), and the circularly polarized plane wave–are found. The solutions to the Landau–Lifshitz equation for the external electromagnetic fields admitting a two-parametric symmetry group, which include as a particular case the above mentioned field configurations, are obtained. Some general properties of the total radiation power of a charged particle are established. In particular, for a circularly polarized wave and constant uniform crossed fields, the total radiation power in the asymptotic regime is independent of the charge and the external field strength, when expressed in terms of the proper-time, and equals a half the rest energy of a charged particle divided by its proper-time. The spectral densities of the radiation power formed on the late time asymptotics are derived for a charged particle moving in the external electromagnetic fields of the simple configurations pointed above. This provides a simple method to verify experimentally that the charged particle has reached the asymptotic regime. -- Highlights: •Late time asymptotics of the solutions to the Lorentz–Dirac equation are studied. •General properties of the total radiation power of electrons are established. •The total radiation power equals a half the rest energy divided by the proper-time. •Spectral densities of radiation formed on the late time asymptotics are derived. •Possible experimental verification of the results is proposed.

  14. H0LiCOW - IV. Lens mass model of HE 0435-1223 and blind measurement of its time-delay distance for cosmology

    NASA Astrophysics Data System (ADS)

    Wong, Kenneth C.; Suyu, Sherry H.; Auger, Matthew W.; Bonvin, Vivien; Courbin, Frederic; Fassnacht, Christopher D.; Halkola, Aleksi; Rusu, Cristian E.; Sluse, Dominique; Sonnenfeld, Alessandro; Treu, Tommaso; Collett, Thomas E.; Hilbert, Stefan; Koopmans, Leon V. E.; Marshall, Philip J.; Rumbaugh, Nicholas

    2017-03-01

    Strong gravitational lenses with measured time delays between the multiple images allow a direct measurement of the time-delay distance to the lens, and thus a measure of cosmological parameters, particularly the Hubble constant, H0. We present a blind lens model analysis of the quadruply imaged quasar lens HE 0435-1223 using deep Hubble Space Telescope imaging, updated time-delay measurements from the COSmological MOnitoring of GRAvItational Lenses (COSMOGRAIL), a measurement of the velocity dispersion of the lens galaxy based on Keck data, and a characterization of the mass distribution along the line of sight. HE 0435-1223 is the third lens analysed as a part of the H0 Lenses in COSMOGRAIL's Wellspring (H0LiCOW) project. We account for various sources of systematic uncertainty, including the detailed treatment of nearby perturbers, the parametrization of the galaxy light and mass profile, and the regions used for lens modelling. We constrain the effective time-delay distance to be D_{Δ t}= 2612_{-191}^{+208} Mpc, a precision of 7.6 per cent. From HE 0435-1223 alone, we infer a Hubble constant of H0 = 73.1_{-6.0}^{+5.7} km s^{-1 Mpc^{-1}} assuming a flat ΛCDM cosmology. The cosmographic inference based on the three lenses analysed by H0LiCOW to date is presented in a companion paper (H0LiCOW Paper V).

  15. A versatile fluorescence lifetime imaging system for scanning large areas with high time and spatial resolution

    NASA Astrophysics Data System (ADS)

    Bernardo, César; Belsley, Michael; de Matos Gomes, Etelvina; Gonçalves, Hugo; Isakov, Dmitry; Liebold, Falk; Pereira, Eduardo; Pires, Vladimiro; Samantilleke, Anura; Vasilevskiy, Mikhail; Schellenberg, Peter

    2014-08-01

    We present a flexible fluorescence lifetime imaging device which can be employed to scan large sample areas with a spatial resolution adjustable from many micrometers down to sub-micrometers and a temporal resolution of 20 picoseconds. Several different applications of the system will be presented including protein microarrays analysis, the scanning of historical samples, evaluation of solar cell surfaces and nanocrystalline organic crystals embedded in electrospun polymeric nanofibers. Energy transfer processes within semiconductor quantum dot superstructures as well as between dye probes and graphene layers were also investigated.

  16. Nature and timing of large landslides within an active orogen, eastern Pamir, China

    NASA Astrophysics Data System (ADS)

    Yuan, Zhaode; Chen, Jie; Owen, Lewis A.; Hedrick, Kathryn A.; Caffee, Marc W.; Li, Wenqiao; Schoenbohm, Lindsay M.; Robinson, Alexander C.

    2013-01-01

    Large-scale landsliding (involving ≫ 106 m3 in volume) is important in landscape development in high mountains. To assess the importance of large landslides in high mountains, four large landslides (Bulunkou, Muztagh, Taheman, and Yimake) were mapped in the NE Chinese Pamir at the westernmost end of the Himalayan-Tibetan orogen and dated using 10Be terrestrial cosmogenic nuclides. The Bulunkou landslide at the southernmost end of Muji Valley is composed of ~ 1.7 × 107 m3 of landslide debris and has an age of 2.0 ± 0.1 ka. The Muztagh landslide, located on the SW side of the massif Muztagh Ata, is composed of ~ 4.7 × 108 m3 of debris, and has an age of 14.3 ± 0.8 ka. The Taheman landslide, located south of Muztagh Ata, is composed of ~ 2.6 × 108 m3 of landslide debris and has an age of 6.8 ± 0.2 ka. The Yimake landslide, on the northern frontal range of the Pamir at the southwestern end of the Tarim basin, is composed of ~ 1.4 × 109 m3 of landslide debris and has an age of 7.1 ± 0.6 ka. Two other large landslides are present in the region, the Aerpa Aigezi (on a tributary of the Gez River) and the Bile Jiyi (on the Yarkand River) landslides, and are composed of ~ 1.6 × 107 m3 and ~ 5.2 × 106 m3 of landslide debris, respectively. However, the Aerpa Aigezi and Bile Jiyi landslides were not studied in as much detail or dated because of their inaccessibility. Given the tectonically active nature of this region, with numerous active faults, and the morphology of the landslides, these landslides were likely triggered by earthquakes. However, other causes — including long-term increased precipitation and geologic bedrock structure — could be important contributing factors in their formation.

  17. Large Scale Winter Time Disturbances in Meteor Winds over Central and Eastern Europe

    NASA Technical Reports Server (NTRS)

    Greisiger, K. M.; Portnyagin, Y. I.; Lysenko, I. A.

    1984-01-01

    Daily zonal wind data of the four pre-MAP-winters 1978/79 to 1981/82 obtained over Central Europe and Eastern Europe by the radar meteor method were studied. Available temperature and satellite radiance data of the middle and upper stratosphere were used for comparison, as well as wind data from Canada. The existence or nonexistence of coupling between the observed large scale zonal wind disturbances in the upper mesopause region (90 to 100 km) and corresponding events in the stratosphere are discussed.

  18. Large volume leukapheresis: Efficacy and safety of processing patient's total blood volume six times.

    PubMed

    Bojanic, Ines; Dubravcic, Klara; Batinic, Drago; Cepulic, Branka Golubic; Mazic, Sanja; Hren, Darko; Nemet, Damir; Labar, Boris

    2011-04-01

    Large-volume leukapheresis (LVL) differs from standard leukapheresis by increased blood flow and an altered anticoagulation regimen. An open issue is to what degree a further increase in processed blood volume is reasonable in terms of higher yields and safety. In 30 LVL performed in patients with hematologic malignancies, 6 total blood volumes were processed. LVL resulted in a higher CD34+ cell yield without a change in graft quality. Although a marked platelet decrease can be expected, LVL is safe and can be recommended as the standard procedure for patients who mobilize low numbers of CD34+ cells and when high number of CD34+ cells are required.

  19. The GW space-time method for the self-energy of large systems

    NASA Astrophysics Data System (ADS)

    Rieger, Martin M.; Steinbeck, L.; White, I. D.; Rojas, H. N.; Godby, R. W.

    1999-03-01

    We present a detailed account of the GW space-time method. The method increases the size of systems whose electronic structure can be studied with a computational implementation of Hedin's GW approximation. At the heart of the method is a representation of the Green function G and the screened Coulomb interaction W in the real-space and imaginary-time domain, which allows a more efficient computation of the self-energy approximation Σ = iGW. For intermediate steps we freely change between representations in real and reciprocal space on the one hand, and imaginary time and imaginary energy on the other, using fast Fourier transforms. The power of the method is demonstrated using the example of Si with artificially increased unit cell sizes.

  20. Large time scale variation in hydrogen emission from Jupiter and Saturn

    NASA Technical Reports Server (NTRS)

    Shemansky, D. E.; Hall, D. T.; Holberg, J. B.

    1988-01-01

    The IUE and Voyager spacecraft observations of Jupiter and Saturn were combined to obtain a consistent measurement of temporal variation of the equatorial subsolar hydrogen emission. The outer planets appear to have rather independent behavior over time scales of the order of 10 yr, particularly in emission from the H Ly alpha line. The time interval from 1978 to the present shows variation of mean equatorial H Ly alpha brightness of 2 at Jupiter and 5 at Saturn. The relative magnitudes of the variations is sufficiently different to suggest that response to input from the Sun is at least nonlinear. The brightness of H2 band emission appears to be relatively more stable than H Ly alpha. There is evidence in IUE observations of a moderate increase in H2 band brightness with increasing time at Jupiter, in opposition to the variation in H Ly alpha.

  1. Experimental determination of quantum-well lifetime effect on large-signal resonant tunneling diode switching time

    NASA Astrophysics Data System (ADS)

    Growden, Tyler A.; Brown, E. R.; Zhang, Weidong; Droopad, Ravi; Berger, Paul R.

    2015-10-01

    An experimental determination is presented of the effect the quantum-well lifetime has on a large-signal resonant tunneling diode (RTD) switching time. Traditional vertical In0.53Ga0.47As/AlAs RTDs were grown, fabricated, and characterized. The switching time was measured with a high-speed oscilloscope and found to be close to the sum of the calculated RC-limited 10%-90% switching time and the quantum-well quasibound-state lifetime. This method displays experimental evidence that the two intrinsic resonant-tunneling characteristic times act independently, and that the quasibound-state lifetime then serves as a quantum-limit on the large-signal speed of RTDs.

  2. Experimental determination of quantum-well lifetime effect on large-signal resonant tunneling diode switching time

    SciTech Connect

    Growden, Tyler A.; Berger, Paul R.; Brown, E. R.; Zhang, Weidong; Droopad, Ravi

    2015-10-12

    An experimental determination is presented of the effect the quantum-well lifetime has on a large-signal resonant tunneling diode (RTD) switching time. Traditional vertical In{sub 0.53}Ga{sub 0.47}As/AlAs RTDs were grown, fabricated, and characterized. The switching time was measured with a high-speed oscilloscope and found to be close to the sum of the calculated RC-limited 10%–90% switching time and the quantum-well quasibound-state lifetime. This method displays experimental evidence that the two intrinsic resonant-tunneling characteristic times act independently, and that the quasibound-state lifetime then serves as a quantum-limit on the large-signal speed of RTDs.

  3. Application of real-time quantitative polymerase chain reaction to monitoring infection of classic swine fever virus and determining optimal harvest time in large-scale production.

    PubMed

    Lin, Ya-Ching; Wu, Sheng-Chi; Yang, Ming-Yu; Chen, Guan-Ting; Li, Tzung-Han; Liau, Ming-Yi

    2013-11-12

    Due to the non-cytopathogenic replication of classical swine fever virus (CSFV) in cell culture, large-scale production of CSFV using bioreactor system remains the problem of monitoring the time of maximum virus production for optimal harvest. In this study, we proposed the application of real-time quantitative PCR assay to monitoring the progress of CSFV infection and yield determination in large scale. The region of NS5B of CSFV responsible for CSFV genome replication was used for the designation of primers and probe. Viral titers determined by the real-time quantitative PCR assay were compared with the conventional cell-culture based method of immunofluorescent staining. Results from large scale production show that a similar profile of CSFV production was successfully outlined by real-time quantitative PCR and virus yields were comparable to the results from immunofluorescent staining assay. By using this method, an optimal harvesting time of the production could be rapidly and precisely determined leading to an improvement in virus harvest. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Large-N expansion for the time-delay matrix of ballistic chaotic cavities

    NASA Astrophysics Data System (ADS)

    Cunden, Fabio Deelan; Mezzadri, Francesco; Simm, Nick; Vivo, Pierpaolo

    2016-11-01

    We consider the 1/N-expansion of the moments of the proper delay times for a ballistic chaotic cavity supporting N scattering channels. In the random matrix approach, these moments correspond to traces of negative powers of Wishart matrices. For systems with and without broken time reversal symmetry (Dyson indices β = 1 and β = 2), we obtain a recursion relation, which efficiently generates the coefficients of the 1/N-expansion of the moments. The integrality of these coefficients and their possible diagrammatic interpretation is discussed.

  5. Using real-time ultrasound to teach living anatomy: an alternative model for large classes.

    PubMed

    Stringer, Mark D; Duncan, Lynda J; Samalia, Latika

    2012-09-07

    Ultrasound is a safe, non-invasive and versatile imaging modality used widely in clinical practice. Several studies have reported using ultrasound imaging to supplement teaching of clinical anatomy to medical students but most have attempted to teach basic ultrasound skills in addition to normal sonographic anatomy. These small group teaching sessions are labour intensive and need appropriate resourcing of equipment and personnel. We report experience of an alternative approach suitable for large classes with more limited resources. A single 1-hour ultrasound demonstration of 'living anatomy' of the abdomen, pelvis and neck was conducted using a young female model as the subject. Scans were performed by an experienced sonographer with images projected on to a large lecture theatre screen; medical student interaction was encouraged by two clinical anatomists. Anonymous evaluation of 152 returned questionnaires (greater than and equal to 63% response rate) showed that more than 80% of respondents considered the session had stimulated and improved their understanding of anatomy. Whilst this method of teaching anatomy using ultrasound does not offer hands-on experience, it does provide students with an introduction to the clinical utility of ultrasound and, by focusing on anatomic findings rather than the acquisition of technical imaging skills, reinforces the learning of clinical anatomy.

  6. Quasi real-time estimation of the moment magnitude of large earthquake from static strain changes

    NASA Astrophysics Data System (ADS)

    Itaba, S.

    2016-12-01

    The 2011 Tohoku-Oki (off the Pacific coast of Tohoku) earthquake, of moment magnitude 9.0, was accompanied by large static strain changes (10-7), as measured by borehole strainmeters operated by the Geological Survey of Japan in the Tokai, Kii Peninsula, and Shikoku regions. A fault model for the earthquake on the boundary between the Pacific and North American plates, based on these borehole strainmeter data, yielded a moment magnitude of 8.7. On the other hand, based on the seismic wave, the prompt report of the magnitude which the Japan Meteorological Agency (JMA) announced just after earthquake occurrence was 7.9. Such geodetic moment magnitudes, derived from static strain changes, can be estimated almost as rapidly as determinations using seismic waves. I have to verify the validity of this method in some cases. In the case of this earthquake's largest aftershock, which occurred 29 minutes after the mainshock. The prompt report issued by JMA assigned this aftershock a magnitude of 7.3, whereas the moment magnitude derived from borehole strain data is 7.6, which is much closer to the actual moment magnitude of 7.7. In order to grasp the magnitude of a great earthquake earlier, several methods are now being suggested to reduce the earthquake disasters including tsunami. Our simple method of using static strain changes is one of the strong methods for rapid estimation of the magnitude of large earthquakes, and useful to improve the accuracy of Earthquake Early Warning.

  7. WarpIV: In situ visualization and analysis of ion accelerator simulations

    DOE PAGES

    Rubel, Oliver; Loring, Burlen; Vay, Jean -Luc; ...

    2016-05-09

    The generation of short pulses of ion beams through the interaction of an intense laser with a plasma sheath offers the possibility of compact and cheaper ion sources for many applications--from fast ignition and radiography of dense targets to hadron therapy and injection into conventional accelerators. To enable the efficient analysis of large-scale, high-fidelity particle accelerator simulations using the Warp simulation suite, the authors introduce the Warp In situ Visualization Toolkit (WarpIV). WarpIV integrates state-of-the-art in situ visualization and analysis using VisIt with Warp, supports management and control of complex in situ visualization and analysis workflows, and implements integrated analyticsmore » to facilitate query- and feature-based data analytics and efficient large-scale data analysis. WarpIV enables for the first time distributed parallel, in situ visualization of the full simulation data using high-performance compute resources as the data is being generated by Warp. The authors describe the application of WarpIV to study and compare large 2D and 3D ion accelerator simulations, demonstrating significant differences in the acceleration process in 2D and 3D simulations. WarpIV is available to the public via https://bitbucket.org/berkeleylab/warpiv. The Warp In situ Visualization Toolkit (WarpIV) supports large-scale, parallel, in situ visualization and analysis and facilitates query- and feature-based analytics, enabling for the first time high-performance analysis of large-scale, high-fidelity particle accelerator simulations while the data is being generated by the Warp simulation suite. Furthermore, this supplemental material https://extras.computer.org/extra/mcg2016030022s1.pdf provides more details regarding the memory profiling and optimization and the Yee grid recentering optimization results discussed in the main article.« less

  8. WarpIV: In situ visualization and analysis of ion accelerator simulations

    SciTech Connect

    Rubel, Oliver; Loring, Burlen; Vay, Jean -Luc; Grote, David P.; Lehe, Remi; Bulanov, Stepan; Vincenti, Henri; Bethel, E. Wes

    2016-05-09

    The generation of short pulses of ion beams through the interaction of an intense laser with a plasma sheath offers the possibility of compact and cheaper ion sources for many applications--from fast ignition and radiography of dense targets to hadron therapy and injection into conventional accelerators. To enable the efficient analysis of large-scale, high-fidelity particle accelerator simulations using the Warp simulation suite, the authors introduce the Warp In situ Visualization Toolkit (WarpIV). WarpIV integrates state-of-the-art in situ visualization and analysis using VisIt with Warp, supports management and control of complex in situ visualization and analysis workflows, and implements integrated analytics to facilitate query- and feature-based data analytics and efficient large-scale data analysis. WarpIV enables for the first time distributed parallel, in situ visualization of the full simulation data using high-performance compute resources as the data is being generated by Warp. The authors describe the application of WarpIV to study and compare large 2D and 3D ion accelerator simulations, demonstrating significant differences in the acceleration process in 2D and 3D simulations. WarpIV is available to the public via https://bitbucket.org/berkeleylab/warpiv. The Warp In situ Visualization Toolkit (WarpIV) supports large-scale, parallel, in situ visualization and analysis and facilitates query- and feature-based analytics, enabling for the first time high-performance analysis of large-scale, high-fidelity particle accelerator simulations while the data is being generated by the Warp simulation suite. Furthermore, this supplemental material https://extras.computer.org/extra/mcg2016030022s1.pdf provides more details regarding the memory profiling and optimization and the Yee grid recentering optimization results discussed in the main article.

  9. WarpIV: In Situ Visualization and Analysis of Ion Accelerator Simulations.

    PubMed

    Rubel, Oliver; Loring, Burlen; Vay, Jean-Luc; Grote, David P; Lehe, Remi; Bulanov, Stepan; Vincenti, Henri; Bethel, E Wes

    2016-01-01

    The generation of short pulses of ion beams through the interaction of an intense laser with a plasma sheath offers the possibility of compact and cheaper ion sources for many applications--from fast ignition and radiography of dense targets to hadron therapy and injection into conventional accelerators. To enable the efficient analysis of large-scale, high-fidelity particle accelerator simulations using the Warp simulation suite, the authors introduce the Warp In situ Visualization Toolkit (WarpIV). WarpIV integrates state-of-the-art in situ visualization and analysis using VisIt with Warp, supports management and control of complex in situ visualization and analysis workflows, and implements integrated analytics to facilitate query- and feature-based data analytics and efficient large-scale data analysis. WarpIV enables for the first time distributed parallel, in situ visualization of the full simulation data using high-performance compute resources as the data is being generated by Warp. The authors describe the application of WarpIV to study and compare large 2D and 3D ion accelerator simulations, demonstrating significant differences in the acceleration process in 2D and 3D simulations. WarpIV is available to the public via https://bitbucket.org/berkeleylab/warpiv. The Warp In situ Visualization Toolkit (WarpIV) supports large-scale, parallel, in situ visualization and analysis and facilitates query- and feature-based analytics, enabling for the first time high-performance analysis of large-scale, high-fidelity particle accelerator simulations while the data is being generated by the Warp simulation suite. This supplemental material https://extras.computer.org/extra/mcg2016030022s1.pdf provides more details regarding the memory profiling and optimization and the Yee grid recentering optimization results discussed in the main article.

  10. WarpIV: In situ visualization and analysis of ion accelerator simulations

    SciTech Connect

    Rubel, Oliver; Loring, Burlen; Vay, Jean -Luc; Grote, David P.; Lehe, Remi; Bulanov, Stepan; Vincenti, Henri; Bethel, E. Wes

    2016-05-09

    The generation of short pulses of ion beams through the interaction of an intense laser with a plasma sheath offers the possibility of compact and cheaper ion sources for many applications--from fast ignition and radiography of dense targets to hadron therapy and injection into conventional accelerators. To enable the efficient analysis of large-scale, high-fidelity particle accelerator simulations using the Warp simulation suite, the authors introduce the Warp In situ Visualization Toolkit (WarpIV). WarpIV integrates state-of-the-art in situ visualization and analysis using VisIt with Warp, supports management and control of complex in situ visualization and analysis workflows, and implements integrated analytics to facilitate query- and feature-based data analytics and efficient large-scale data analysis. WarpIV enables for the first time distributed parallel, in situ visualization of the full simulation data using high-performance compute resources as the data is being generated by Warp. The authors describe the application of WarpIV to study and compare large 2D and 3D ion accelerator simulations, demonstrating significant differences in the acceleration process in 2D and 3D simulations. WarpIV is available to the public via https://bitbucket.org/berkeleylab/warpiv. The Warp In situ Visualization Toolkit (WarpIV) supports large-scale, parallel, in situ visualization and analysis and facilitates query- and feature-based analytics, enabling for the first time high-performance analysis of large-scale, high-fidelity particle accelerator simulations while the data is being generated by the Warp simulation suite. Furthermore, this supplemental material https://extras.computer.org/extra/mcg2016030022s1.pdf provides more details regarding the memory profiling and optimization and the Yee grid recentering optimization results discussed in the main article.

  11. High-Temperature-Short-Time Annealing Process for High-Performance Large-Area Perovskite Solar Cells.

    PubMed

    Kim, Minjin; Kim, Gi-Hwan; Oh, Kyoung Suk; Jo, Yimhyun; Yoon, Hyun; Kim, Ka-Hyun; Lee, Heon; Kim, Jin Young; Kim, Dong Suk

    2017-06-27

    Organic-inorganic hybrid metal halide perovskite solar cells (PSCs) are attracting tremendous research interest due to their high solar-to-electric power conversion efficiency with a high possibility of cost-effective fabrication and certified power conversion efficiency now exceeding 22%. Although many effective methods for their application have been developed over the past decade, their practical transition to large-size devices has been restricted by difficulties in achieving high performance. Here we report on the development of a simple and cost-effective production method with high-temperature and short-time annealing processing to obtain uniform, smooth, and large-size grain domains of perovskite films over large areas. With high-temperature short-time annealing at 400 °C for 4 s, the perovskite film with an average domain size of 1 μm was obtained, which resulted in fast solvent evaporation. Solar cells fabricated using this processing technique had a maximum power conversion efficiency exceeding 20% over a 0.1 cm(2) active area and 18% over a 1 cm(2) active area. We believe our approach will enable the realization of highly efficient large-area PCSs for practical development with a very simple and short-time procedure. This simple method should lead the field toward the fabrication of uniform large-scale perovskite films, which are necessary for the production of high-efficiency solar cells that may also be applicable to several other material systems for more widespread practical deployment.

  12. H0LiCOW – IV. Lens mass model of HE 0435-1223 and blind measurement of its time-delay distance for cosmology

    DOE PAGES

    Wong, Kenneth C.; Suyu, Sherry H.; Auger, Matthew W.; ...

    2016-11-29

    Strong gravitational lenses with measured time delays between the multiple images allow a direct measurement of the time-delay distance to the lens, and thus a measure of cosmological parameters, particularly the Hubble constant, H0. We present a blind lens model analysis of the quadruply imaged quasar lens HE 0435-1223 using deep Hubble Space Telescope imaging, updated time-delay measurements from the COSmological MOnitoring of GRAvItational Lenses (COSMOGRAIL), a measurement of the velocity dispersion of the lens galaxy based on Keck data, and a characterization of the mass distribution along the line of sight. HE 0435-1223 is the third lens analysed as a part of the H0 Lenses in COSMOGRAIL's Wellspring (H0LiCOW) project. We account for various sources of systematic uncertainty, including the detailed treatment of nearby perturbers, the parametrization of the galaxy light and mass profile, and the regions used for lens modelling. We constrain the effective time-delay distance to be DΔt=2612more » $$+208\\atop{-191}$$Mpc, a precision of 7.6 per cent. From HE 0435-1223 alone, we infer a Hubble constant of H0=73.1$$+5.7\\atop{-6.0}$$kms-1Mpc-1 assuming a flat ΛCDM cosmology. Lastly, the cosmographic inference based on the three lenses analysed by H0LiCOW to date is presented in a companion paper (H0LiCOW Paper V).« less

  13. H0LiCOW – IV. Lens mass model of HE 0435-1223 and blind measurement of its time-delay distance for cosmology

    SciTech Connect

    Wong, Kenneth C.; Suyu, Sherry H.; Auger, Matthew W.; Bonvin, Vivien; Courbin, Frederic; Fassnacht, Christopher D.; Halkola, Aleksi; Rusu, Cristian E.; Sluse, Dominique; Sonnenfeld, Alessandro; Treu, Tommaso; Collett, Thomas E.; Hilbert, Stefan; Koopmans, Leon V. E.; Marshall, Philip J.; Rumbaugh, Nicholas

    2016-11-29

    Strong gravitational lenses with measured time delays between the multiple images allow a direct measurement of the time-delay distance to the lens, and thus a measure of cosmological parameters, particularly the Hubble constant, H0. We present a blind lens model analysis of the quadruply imaged quasar lens HE 0435-1223 using deep Hubble Space Telescope imaging, updated time-delay measurements from the COSmological MOnitoring of GRAvItational Lenses (COSMOGRAIL), a measurement of the velocity dispersion of the lens galaxy based on Keck data, and a characterization of the mass distribution along the line of sight. HE 0435-1223 is the third lens analysed as a part of the H0 Lenses in COSMOGRAIL's Wellspring (H0LiCOW) project. We account for various sources of systematic uncertainty, including the detailed treatment of nearby perturbers, the parametrization of the galaxy light and mass profile, and the regions used for lens modelling. We constrain the effective time-delay distance to be DΔt=2612$+208\\atop{-191}$Mpc, a precision of 7.6 per cent. From HE 0435-1223 alone, we infer a Hubble constant of H0=73.1$+5.7\\atop{-6.0}$kms-1Mpc-1 assuming a flat ΛCDM cosmology. Lastly, the cosmographic inference based on the three lenses analysed by H0LiCOW to date is presented in a companion paper (H0LiCOW Paper V).

  14. An effective method to read out large scintillator areas with precise timing

    NASA Astrophysics Data System (ADS)

    Bähr, J.; Grabosch, H.-J.; Kantserov, V.; Leich, H.; Leiste, R.; Nahnhauer, R.

    1998-11-01

    Using scintillator tile technology several square meters of plastic scintillator are read out by only two photomultipliers with a time precision of about 1.5 nsec. Two examples are discussed to build a detector based on this technology to search for cosmic muons and neutrinos.

  15. Citizen journalism in a time of crisis: lessons from a large-scale California wildfire

    Treesearch

    S. Gillette; J. Taylor; D.J. Chavez; R. Hodgson; J. Downing

    2007-01-01

    The accessibility of news production tools through consumer communication technology has made it possible for media consumers to become media producers. The evolution of media consumer to media producer has important implications for the shape of public discourse during a time of crisis. Citizen journalists cover crisis events using camera cell phones and digital...

  16. Imaginary time propagation code for large-scale two-dimensional eigenvalue problems in magnetic fields

    NASA Astrophysics Data System (ADS)

    Luukko, P. J. J.; Räsänen, E.

    2013-03-01

    We present a code for solving the single-particle, time-independent Schrödinger equation in two dimensions. Our program utilizes the imaginary time propagation (ITP) algorithm, and it includes the most recent developments in the ITP method: the arbitrary order operator factorization and the exact inclusion of a (possibly very strong) magnetic field. Our program is able to solve thousands of eigenstates of a two-dimensional quantum system in reasonable time with commonly available hardware. The main motivation behind our work is to allow the study of highly excited states and energy spectra of two-dimensional quantum dots and billiard systems with a single versatile code, e.g., in quantum chaos research. In our implementation we emphasize a modern and easily extensible design, simple and user-friendly interfaces, and an open-source development philosophy. Catalogue identifier: AENR_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AENR_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU General Public License version 3 No. of lines in distributed program, including test data, etc.: 11310 No. of bytes in distributed program, including test data, etc.: 97720 Distribution format: tar.gz Programming language: C++ and Python. Computer: Tested on x86 and x86-64 architectures. Operating system: Tested under Linux with the g++ compiler. Any POSIX-compliant OS with a C++ compiler and the required external routines should suffice. Has the code been vectorised or parallelized?: Yes, with OpenMP. RAM: 1 MB or more, depending on system size. Classification: 7.3. External routines: FFTW3 (http://www.fftw.org), CBLAS (http://netlib.org/blas), LAPACK (http://www.netlib.org/lapack), HDF5 (http://www.hdfgroup.org/HDF5), OpenMP (http://openmp.org), TCLAP (http://tclap.sourceforge.net), Python (http://python.org), Google Test (http://code.google.com/p/googletest/) Nature of problem: Numerical calculation

  17. Cardiac related death in thalassaemia major: time trend and risk factors in a large Greek Unit.

    PubMed

    Chouliaras, Giorgos; Yiannoutsos, Constantin T; Berdoukas, Vasilios; Ladis, Vassilios

    2009-05-01

    Cardiac complications are the leading cause of death in thalassaemic patients (TM) worldwide. Improved management protocols including new chelators and imaging have reduced cardiac-related deaths but also require more advanced analytical methods to reflect temporal fluctuations in mortality risk. To evaluate time patterns of risk of cardiac death in TM patients according to birth cohort, gender and degree of haemosiderosis and to apply new flexible methods of analysis that may allow assessment of trends in risks as affected by innovations in management. Cardiac-free survival and time trend of the risk of cardiac-related death were assessed in 648 transfusion-depended thalassaemic patients (48.3% females) managed in a single unit located in Athens, Greece. Patients were classified according to birth cohort (prior or after 1/1/1975) and according to the severity of haemosiderosis (mild, moderate and severe) as estimated by the mean ferritin levels during the last 5 yr of follow-up. The median time of observation was 27.8 yr and 84 cardiac deaths were recorded. A parametric analysis predicted a non-monotonous time pattern for the cardiac risk with an initial increasing phase until the fourth decade of life followed by a drop off in deaths. Women have 23% longer life expectancy than men (P = 0.010) while patients born after 1975 die of heart complications at an older age compared to those born prior to 1975 (time ratio = 1.34, P = 0.003). Patients with mild and moderate haemosiderosis lived 89% (P < 0.001) and 43% (P < 0.001) longer, respectively, compared with patients with severe haemosiderosis. These results on risk of death in thalassaemia, accord with expectations. This type of analysis will be useful in the future when the expected impact of cardiac MRI with appropriate tailoring of chelation therapy using all current and future options will modify the pattern of risk of cardiac death observed to date.

  18. Large-scale fires and time trends of PCDDS/DFs in sediments.

    PubMed

    Sakai, S; Deguchi, S; Takatsuki, H; Uchibo, A

    2001-01-01

    Drastic increases in PCDDs/DFs concentrations were identified in the uppermost layers of a sediment core sample taken from the coastal area of Kobe City. As large-scale fires caused by the Great Hanshin-Awaji earthquake were deemed to be a possible cause, we performed additional sampling of sediment cores and surface sediment samples, estimating the total amount of PCDDs/DFs released from fires and presuming the load to sediments by individual transport routes, such as air and water, using an air diffusion model to investigate the influence of fires. The total amount of PCDDs/DFs released from fires was estimated at 2000 g-total PCDDs/DFs, 22 g-TEQ. Increases in PCDDs/DFs generated in fires were principally transported through water rather than air. If 20% of the total PCDDs/DFs formed in fires had entered water, it would correspond to the entire increase of PCDDs/DFs concentration in sediment cores.

  19. Large-deformation and long-time behavior of entangled melts in complex geometries

    NASA Astrophysics Data System (ADS)

    Zhu, Xiangyang; Wang, Shi-Qing

    2012-02-01

    Recent particle-tracking velocimetric (PTV) observations have revealed strain localization either during startup shear beyond the stress overshoot or after a large step shear of entangled polymers [e.g., Macromolecules, 42, 6261 (2009)]. The physical pictures leading to these decohesion events have been put forward [J. Chem. Phys. 127, 064903(2007); J. Rheol. 53, 1389 (2009)]. In this presentation we apply the particle-tracking velocimetric method [Macromol. Mater. Engr. 292, 15 (2007)] to study similar strain localization phenomena originating from yielding of the entanglement network in other forms of deformation including uniaxial extension, ``squeeze flow'' and extrusion of polymers from a wide open space into a narrow opening. The striking discontinuities in the velocity profile can all be understood in terms of a shear yielding criterion. The research is funded, in part, by a grant from the National Science Foundation (CMMI-0926522)

  20. Does Time Spent Online Have an Influence on Student Performance? Evidence for a Large Business Studies Class

    ERIC Educational Resources Information Center

    Korkofingas, Con; Macri, Joseph

    2013-01-01

    This paper examines, using regression modelling, whether a statistically significant relationship exists between the time spent by a student using the course website and the student's assessment performance for a large third year university business forecasting course. We utilise the online tracking system in Blackboard, a web-based software…

  1. Examining the Content of Head Start Teachers' Literacy Instruction within Two Activity Contexts during Large-Group Circle Time

    ERIC Educational Resources Information Center

    Zhang, Chenyi; Diamond, Karen E.; Powell, Douglas R.

    2015-01-01

    Large-group circle time is an important component of many preschool classrooms' daily schedules. This study scrutinized the teaching content of Head Start teachers' literacy instruction (i.e., the types of literacy concept embedded within the instruction, lexical characteristics of teachers' talk, and elaborations on literacy knowledge) in two…

  2. Computing the pressure for Axiom-A attractors by time series and large deviations for the Lyapunov exponent

    SciTech Connect

    Vaienti, S. Dipartimento di Fisica, Bologna )

    1989-08-01

    For the Axiom-A attractors a relation is given between the topological pressure and the spectrum of the generalized Lyapunov exponents. As a consequence, a simple formula is found to compute the topological entropy of the attractor by means of a time series. The results are used to compute the large deviations for positive Lyapunov exponents.

  3. Examining the Content of Head Start Teachers' Literacy Instruction within Two Activity Contexts during Large-Group Circle Time

    ERIC Educational Resources Information Center

    Zhang, Chenyi; Diamond, Karen E.; Powell, Douglas R.

    2015-01-01

    Large-group circle time is an important component of many preschool classrooms' daily schedules. This study scrutinized the teaching content of Head Start teachers' literacy instruction (i.e., the types of literacy concept embedded within the instruction, lexical characteristics of teachers' talk, and elaborations on literacy knowledge) in two…

  4. A Comparative Study of Small, Part-Time, Retirement and Large Farms: Three Counties in Central and West Tennessee.

    ERIC Educational Resources Information Center

    Woodworth, Roger C.; And Others

    Personal interviews with 344 randomly selected farm operators in three Tennessee counties revealed differences in the characteristics, aspirations, and attitudes of large, small, part time, and retired farmers. These differences are important in understanding agricultural potentials, the impact of agricultural programs, and the future structure of…

  5. A 3D time reversal cavity for the focusing of high-intensity ultrasound pulses over a large volume

    NASA Astrophysics Data System (ADS)

    Robin, J.; Arnal, B.; Tanter, M.; Pernot, M.

    2017-02-01

    Shock wave ultrasound therapy techniques, increasingly used for non-invasive surgery, require extremely high pressure amplitudes in precise focal spots, and large high-power transducers arranged on a spherical shell are usually used to achieve that. This solution allows limited steering of the beam around the geometrical focus of the device at the cost of a large number of transducer elements, and the treatment of large and moving organs like the heart is challenging or impossible. This paper validates numerically and experimentally the possibility of using a time reversal cavity (TRC) for the same purpose. A 128-element, 1 MHz power transducer combined with different multiple scattering media in a TRC was used. We were able to focus high-power ultrasound pulses over a large volume in a controlled manner, with a limited number of transducer elements. We reached sufficiently high pressure amplitudes to erode an Ultracal® target over a 10 cm2 area.

  6. A Phase Locked High Speed Real-Time Interferometry System for Large Amplitude Unsteady Flows

    NASA Technical Reports Server (NTRS)

    Chandrasekhara, M. S.; Squires, D. D.; Wilder, M. C.; Carr, L. W.; Kutler, Paul (Technical Monitor)

    1994-01-01

    A high speed phase locked interferometry system has been designed and developed for real-time measurements of the dynamic stall flow over a pitching airfoil. Point diffraction interferograms of incipient flow separation over a sinusoidally oscillating airfoil have been obtained at rates of up to 20 KHz and for free stream Mach numbers of 0.3 and 0.45. The images were recorded on ASA 125 and ASA 400 film using a drum camera. Special electronic timing and synchronizing circuits were developed to trigger the laser light source from the camera, and to initiate acquisition of the interferogram sequence from any desired phase angle of oscillation. The airfoil instantaneous angle of attack data provided by an optical encoder was recorded via a FIFO and in EPROM into a microcomputer. The interferograms have been analyzed using software developed in-house to get quantitative flow density and pressure distributions.

  7. Dynamics and pattern formation in large systems of spatially-coupled oscillators with finite response times.

    PubMed

    Lee, Wai Shing; Restrepo, Juan G; Ott, Edward; Antonsen, Thomas M

    2011-06-01

    We consider systems of many spatially distributed phase oscillators that interact with their neighbors. Each oscillator is allowed to have a different natural frequency, as well as a different response time to the signals it receives from other oscillators in its neighborhood. Using the ansatz of Ott and Antonsen [Chaos 18, 037113 (2008)] and adopting a strategy similar to that employed in the recent work of Laing [Physica D 238, 1569 (2009)], we reduce the microscopic dynamics of these systems to a macroscopic partial-differential-equation description. Using this macroscopic formulation, we numerically find that finite oscillator response time leads to interesting spatiotemporal dynamical behaviors including propagating fronts, spots, target patterns, chimerae, spiral waves, etc., and we study interactions and evolutionary behaviors of these spatiotemporal patterns.

  8. Explicit large time-step schemes for the shallow water equations

    NASA Technical Reports Server (NTRS)

    Turkel, E.; Zwas, G.

    1979-01-01

    Modifications to explicit finite difference schemes for solving the shallow water equations for meteorological applications by increasing the time step for the fast gravity waves are analyzed. Terms associated with the gravity waves in the shallow water equations are treated on a coarser grid than those associated with the slow Rossby waves, which contain much more of the available energy and must be treated with higher accuracy, enabling a several-fold increase in time step without degrading the accuracy of the solution. The method is presented in Cartesian and spherical coordinates for a rotating earth, using generalized leapfrog, frozen coefficient, and Fourier filtering finite difference schemes. Computational results verify the numerical stability of the approach.

  9. Synthesis of feedback systems with large plant ignorance for prescribed time domain tolerances

    NASA Technical Reports Server (NTRS)

    Horowitz, I. M.; Sidi, M.

    1971-01-01

    There is given a minimum-phase plant transfer function, with prescribed bounds on its parameter values. The plant is imbedded in a two-degree-of freedom feedback system, which is to be designed such that the system time response to a deterministic input lies within specified boundaries. Subject to the above, the design should be such as to minimize the effect of sensor noise at the input to the plant. This report presents a design procedure for this purpose, based on frequency response concepts. The time-domain tolerances are translated into equivalent frequency response tolerances. The latter lead to bounds on the loop transmission function in the form of continuous curves on the Nichols chart. The properties of the loop transmission function which satisfy these bounds with minimum effect of sensor noise, are derived.

  10. A new approach for the simulation of ESR lineshapes over a large range of correlation times

    NASA Astrophysics Data System (ADS)

    Eviatar, H.; van Faassen, E.; Levine, Y. K.

    1992-07-01

    A new approach for the simulation of ESR lineshapes over a range of correlation times extending from the Redfield limit to the rigid limit is described. The use of a separable operator for the dynamics of a spin label in a uniaxial liquid crystal ("Kangaroo dynamics") allows an algebraic solution of the stochastic Liouville equation. This procedure avoids the numerical instability resulting from clustering of eigenvalues inherent in the conventional solution using an eigenfunction expansion.

  11. Time Domain Analysis and Synthesis of Robust Controllers for Large Scale LQG (Linear Quadratic Gaussian) Regulators.

    DTIC Science & Technology

    1983-08-31

    Time domain analysis of stability 3 robustness. B. Computer software and application 27 .1 examupl es. III. Conclusions & Recommendations for Future...performance requirements may not be met by g that design. Thus, simultaneous consideration of stability and performance -. in the design process is...the design process have been scarce. Towards this direction, research was initiated on these aspects by the author during the Summer IFaculty Research

  12. Time Domain Design of Robust Controllers for LQG (Linear Quadratic Gaussian); Application to Large Space Structures

    DTIC Science & Technology

    1985-12-01

    schemes involving more general perturbations. Also Desoer et al [8] have established conditions for stability robustness of linear multivarible...address regulators with quadratic performance indices. Desoer et al [8] have established conditions for stability robust- ness of linear...p. 45-46. 8. Desoer , C.A., Callier, F.M. and Chan, W.S., "Robustness of Stability Conditions for Linear Time Invariant Feedback Systems," IEEE

  13. Existence and large time behavior for a stochastic model of modified magnetohydrodynamic equations

    NASA Astrophysics Data System (ADS)

    Razafimandimby, Paul André; Sango, Mamadou

    2015-10-01

    In this paper, we study a system of nonlinear stochastic partial differential equations describing the motion of turbulent non-Newtonian media in the presence of fluctuating magnetic field. The system is basically obtained by a coupling of the dynamical equations of a non-Newtonian fluids having p-structure and the Maxwell equations. We mainly show the existence of weak martingale solutions and their exponential decay when time goes to infinity.

  14. Response Time Distributions in Rapid Chess: A Large-Scale Decision Making Experiment

    PubMed Central

    Sigman, Mariano; Etchemendy, Pablo; Slezak, Diego Fernández; Cecchi, Guillermo A.

    2010-01-01

    Rapid chess provides an unparalleled laboratory to understand decision making in a natural environment. In a chess game, players choose consecutively around 40 moves in a finite time budget. The goodness of each choice can be determined quantitatively since current chess algorithms estimate precisely the value of a position. Web-based chess produces vast amounts of data, millions of decisions per day, incommensurable with traditional psychological experiments. We generated a database of response times (RTs) and position value in rapid chess games. We measured robust emergent statistical observables: (1) RT distributions are long-tailed and show qualitatively distinct forms at different stages of the game, (2) RT of successive moves are highly correlated both for intra- and inter-player moves. These findings have theoretical implications since they deny two basic assumptions of sequential decision making algorithms: RTs are not stationary and can not be generated by a state-function. Our results also have practical implications. First, we characterized the capacity of blunders and score fluctuations to predict a player strength, which is yet an open problem in chess softwares. Second, we show that the winning likelihood can be reliably estimated from a weighted combination of remaining times and position evaluation. PMID:21031032

  15. Agent-based Large-Scale Emergency Evacuation Using Real-Time Open Government Data

    SciTech Connect

    Lu, Wei; Liu, Cheng; Bhaduri, Budhendra L

    2014-01-01

    The open government initiatives have provided tremendous data resources for the transportation system and emergency services in urban areas. This paper proposes a traffic simulation framework using high temporal resolution demographic data and real time open government data for evacuation planning and operation. A comparison study using real-world data in Seattle, Washington is conducted to evaluate the framework accuracy and evacuation efficiency. The successful simulations of selected area prove the concept to take advantage open government data, open source data, and high resolution demographic data in emergency management domain. There are two aspects of parameters considered in this study: user equilibrium (UE) conditions of traffic assignment model (simple Non-UE vs. iterative UE) and data temporal resolution (Daytime vs. Nighttime). Evacuation arrival rate, average travel time, and computation time are adopted as Measure of Effectiveness (MOE) for evacuation performance analysis. The temporal resolution of demographic data has significant impacts on urban transportation dynamics during evacuation scenarios. Better evacuation performance estimation can be approached by integrating both Non-UE and UE scenarios. The new framework shows flexibility in implementing different evacuation strategies and accuracy in evacuation performance. The use of this framework can be explored to day-to-day traffic assignment to support daily traffic operations.

  16. The COSMOS HI Large Extragalactic Survey (CHILES): Probing HI Across Cosmic Time

    NASA Astrophysics Data System (ADS)

    Fernandez, Ximena; van Gorkom, Jacqueline H.; Momjian, Emmanuel; Chiles Team

    2015-01-01

    Hydrogen (HI) is the most abundant element in the Universe, and surprisingly, we know very little about the neutral hydrogen beyond z~0.08. The recently upgraded VLA makes it now possible to image the HI in galaxies beyond the local Universe. We are using the broad bandwidth of the VLA to instantaneously probe HI from z=0 to z=0.5 in one pointing of the COSMOS field. Once CHILES is complete, we will have HI images of 300 galaxies across cosmic time in different environments. These images will have a spatial resolution of 0.5 kpc for nearby galaxies and 30 kpc at z~0.5, and a velocity resolution of 7 km/s. In preparation for CHILES, we carried out a pilot study that observed the same pointing out to z~0.2, and detected HI in 33 galaxies in our volume. I will describe the science goals of CHILES, what we learned from the pilot study, and present preliminary results for the first 200 hours of observations of the full survey. After 1002 hours of integration time, we will have high-resolution HI images that will help us understand galaxy evolution across cosmic time and test predictions made by cosmological simulations.

  17. PLATO IV Accountancy Index.

    ERIC Educational Resources Information Center

    Pondy, Dorothy, Comp.

    The catalog was compiled to assist instructors in planning community college and university curricula using the 48 computer-assisted accountancy lessons available on PLATO IV (Programmed Logic for Automatic Teaching Operation) for first semester accounting courses. It contains information on lesson access, lists of acceptable abbreviations for…

  18. Little Jiffy, Mark IV

    ERIC Educational Resources Information Center

    Kaiser, Henry F.; Rice, John

    1974-01-01

    In this paper three changes and one new development for the method of exploratory factor analysis (a second generation Little Jiffy) developed by Kaiser are described. Following this short description a step-by-step computer algorithm of the revised method, dubbed Little Jiffy, Mark IV is presented. (MP)

  19. IVS Technology Coordinator Report

    NASA Technical Reports Server (NTRS)

    Whitney, Alan

    2013-01-01

    This report of the Technology Coordinator includes the following: 1) continued work to implement the new VLBI2010 system, 2) the 1st International VLBI Technology Workshop, 3) a VLBI Digital- Backend Intercomparison Workshop, 4) DiFX software correlator development for geodetic VLBI, 5) a review of progress towards global VLBI standards, and 6) a welcome to new IVS Technology Coordinator Bill Petrachenko.

  20. Emergence of network structure due to spike-timing-dependent plasticity in recurrent neuronal networks IV: structuring synaptic pathways among recurrent connections.

    PubMed

    Gilson, Matthieu; Burkitt, Anthony N; Grayden, David B; Thomas, Doreen A; van Hemmen, J Leo

    2009-12-01

    In neuronal networks, the changes of synaptic strength (or weight) performed by spike-timing-dependent plasticity (STDP) are hypothesized to give rise to functional network structure. This article investigates how this phenomenon occurs for the excitatory recurrent connections of a network with fixed input weights that is stimulated by external spike trains. We develop a theoretical framework based on the Poisson neuron model to analyze the interplay between the neuronal activity (firing rates and the spike-time correlations) and the learning dynamics, when the network is stimulated by correlated pools of homogeneous Poisson spike trains. STDP can lead to both a stabilization of all the neuron firing rates (homeostatic equilibrium) and a robust weight specialization. The pattern of specialization for the recurrent weights is determined by a relationship between the input firing-rate and correlation structures, the network topology, the STDP parameters and the synaptic response properties. We find conditions for feed-forward pathways or areas with strengthened self-feedback to emerge in an initially homogeneous recurrent network.

  1. An extensive spectroscopic time series of three Wolf-Rayet stars - I. The lifetime of large-scale structures in the wind of WR 134

    NASA Astrophysics Data System (ADS)

    Aldoretta, E. J.; St-Louis, N.; Richardson, N. D.; Moffat, A. F. J.; Eversberg, T.; Hill, G. M.; Shenar, T.; Artigau, É.; Gauza, B.; Knapen, J. H.; Kubát, J.; Kubátová, B.; Maltais-Tariant, R.; Muñoz, M.; Pablo, H.; Ramiaramanantsoa, T.; Richard-Laferrière, A.; Sablowski, D. P.; Simón-Díaz, S.; St-Jean, L.; Bolduan, F.; Dias, F. M.; Dubreuil, P.; Fuchs, D.; Garrel, T.; Grutzeck, G.; Hunger, T.; Küsters, D.; Langenbrink, M.; Leadbeater, R.; Li, D.; Lopez, A.; Mauclaire, B.; Moldenhawer, T.; Potter, M.; dos Santos, E. M.; Schanne, L.; Schmidt, J.; Sieske, H.; Strachan, J.; Stinner, E.; Stinner, P.; Stober, B.; Strandbaek, K.; Syder, T.; Verilhac, D.; Waldschläger, U.; Weiss, D.; Wendt, A.

    2016-08-01

    During the summer of 2013, a 4-month spectroscopic campaign took place to observe the variabilities in three Wolf-Rayet stars. The spectroscopic data have been analysed for WR 134 (WN6b), to better understand its behaviour and long-term periodicity, which we interpret as arising from corotating interaction regions (CIRs) in the wind. By analysing the variability of the He II λ5411 emission line, the previously identified period was refined to P = 2.255 ± 0.008 (s.d.) d. The coherency time of the variability, which we associate with the lifetime of the CIRs in the wind, was deduced to be 40 ± 6 d, or ˜18 cycles, by cross-correlating the variability patterns as a function of time. When comparing the phased observational grey-scale difference images with theoretical grey-scales previously calculated from models including CIRs in an optically thin stellar wind, we find that two CIRs were likely present. A separation in longitude of Δφ ≃ 90° was determined between the two CIRs and we suggest that the different maximum velocities that they reach indicate that they emerge from different latitudes. We have also been able to detect observational signatures of the CIRs in other spectral lines (C IV λλ5802,5812 and He I λ5876). Furthermore, a DAC was found to be present simultaneously with the CIR signatures detected in the He I λ5876 emission line which is consistent with the proposed geometry of the large-scale structures in the wind. Small-scale structures also show a presence in the wind, simultaneously with the larger scale structures, showing that they do in fact co-exist.

  2. Mercury and drought along the lower Carson River, Nevada: IV. Snowy egret post-fledging dispersal, timing of migration and survival, 2002-2004.

    PubMed

    Henny, Charles J; Hill, Elwood F; Grove, Robert A; Chelgren, Nathan D; Haggerty, Patricia K

    2017-01-01

    This telemetry study is an extension of our 1997-2006 research on historical mercury contamination on snowy egrets (Egretta thula) up to ~ 20 days of age. Findings from initial studies at the mercury-contaminated Carson River colony at Lahontan Reservoir (LR) and a similar-sized reference (REF) colony on the Humboldt River included mercury-related physiological, biochemical, histopathological and reproductive effects up to ~20 days of age; with poor water years (2000-04), i.e., reduced prey availability, exacerbating effects. Herein, we compare timing of dispersal and migration at LR vs. REF, but the primary question now addressed is "whether survival of young mercury-exposed snowy egrets from LR would be further compromised beyond ~20 days of age? " Based upon telemetry signals until 90-110 days of age (including dead bird counts and survival rate estimates), we conclude that mercury did not further compromise survival. Dead bird counts and survival rate estimates included time in the colony when fed by adults, plus the critical period when young dispersed from the colony to forage independently. The extended drought during this 3-year study was most critical in 2002 when production of ~20d old egrets at LR was only 0.24 young/nest. In 2002, survival rates were low at both colonies and we documented the highest counts of dead egrets for both colonies. We suggest the losses in 2002 beyond 20 days of age were more a function of prey availability influenced by drought than exposure to mercury, especially at LR, because higher mercury concentrations, higher survival rates and fewer dead birds were documented at LR in 2003 when water conditions improved. Furthermore, total mercury (THg) in blood in 2003 was more than double 2002 (geometric mean, 3.39 vs 1.47µg/g wet weight (ww). This higher THg exposure at LR in 2003 was associated with a redistribution of parent and post-dispersal feeding activities upstream (where there was higher mercury from historic mining

  3. Mercury and drought along the lower Carson River, Nevada: IV. Snowy egret post-fledging dispersal, timing of migration and survival, 2002–2004

    USGS Publications Warehouse

    Henny, Charles J.; Hill, Elwood F.; Grove, Robert A.; Chelgren, Nathan; Haggerty, Patricia K.

    2017-01-01

    This telemetry study is an extension of our 1997–2006 research on historical mercury contamination on snowy egrets (Egretta thula) up to ~ 20 days of age. Findings from initial studies at the mercury-contaminated Carson River colony at Lahontan Reservoir (LR) and a similar-sized reference (REF) colony on the Humboldt River included mercury-related physiological, biochemical, histopathological and reproductive effects up to ~20 days of age; with poor water years (2000–04), i.e., reduced prey availability, exacerbating effects. Herein, we compare timing of dispersal and migration at LR vs. REF, but the primary question now addressed is “whether survival of young mercury-exposed snowy egrets from LR would be further compromised beyond ~20 days of age? ” Based upon telemetry signals until 90–110 days of age (including dead bird counts and survival rate estimates), we conclude that mercury did not further compromise survival. Dead bird counts and survival rate estimates included time in the colony when fed by adults, plus the critical period when young dispersed from the colony to forage independently. The extended drought during this 3-year study was most critical in 2002 when production of ~20 d old egrets at LR was only 0.24 young/nest. In 2002, survival rates were low at both colonies and we documented the highest counts of dead egrets for both colonies. We suggest the losses in 2002 beyond 20 days of age were more a function of prey availability influenced by drought than exposure to mercury, especially at LR, because higher mercury concentrations, higher survival rates and fewer dead birds were documented at LR in 2003 when water conditions improved. Furthermore, total mercury (THg) in blood in 2003 was more than double 2002 (geometric mean, 3.39 vs 1.47 µg/g wet weight (ww). This higher THg exposure at LR in 2003 was associated with a redistribution of parent and post-dispersal feeding activities upstream (where there was higher mercury from historic

  4. Efficient formalism for large-scale ab initio molecular dynamics based on time-dependent density functional theory.

    PubMed

    Alonso, J L; Andrade, X; Echenique, P; Falceto, F; Prada-Gracia, D; Rubio, A

    2008-08-29

    A new "on the fly" method to perform Born-Oppenheimer ab initio molecular dynamics (AIMD) simulations is presented. Inspired by Ehrenfest dynamics in time-dependent density functional theory, the electronic orbitals are evolved by a Schrödinger-like equation, where the orbital time derivative is multiplied by a parameter. This parameter controls the time scale of the fictitious electronic motion and speeds up the calculations with respect to standard Ehrenfest dynamics. In contrast with other methods, wave function orthogonality needs not be imposed as it is automatically preserved, which is of paramount relevance for large-scale AIMD simulations.

  5. S0819: Carboplatin and Paclitaxel With or Without Bevacizumab and/or Cetuximab in Treating Patients With Stage IV or Recurrent Non-Small Cell Lung Cancer

    ClinicalTrials.gov

    2017-03-16

    Recurrent Large Cell Lung Carcinoma; Recurrent Lung Adenocarcinoma; Recurrent Squamous Cell Lung Carcinoma; Stage IV Large Cell Lung Carcinoma; Stage IV Lung Adenocarcinoma; Stage IV Squamous Cell Lung Carcinoma

  6. Dust in Jupiter's magnetosphere. I - Physical processes. II - Origin of the ring. III - Time variations. IV - Effect on magnetospheric electrons and ions

    NASA Technical Reports Server (NTRS)

    Morfill, G. E.; Gruen, E.; Johnson, T. V.

    1980-01-01

    The physical processes acting on charged microscopic dust grains in the Jovian atmosphere involve electromagnetic forces which dominate dust particle dynamics and diffusion across field lines resulting from random charge fluctuations of the dust grains. A model of the Jovian ring hypothesizes that the 'visible' ring particles are produced by erosive collisions between an assumed population of kilometer-sized parent bodies and submicron-sized magnetospheric dust particles. Fluctuations in the ring topology and intensity are determined over various time scales, showing that the ring is a quasipermanent and quasistable characteristic of the Jovian system. Finally, the interaction of the Jovian energetic belt electrons and the Jovian plasma with an ambient dust population is examined; the distribution of dust ejected from Io in the inner magnetosphere and losses of magnetospheric ions and electrons due to direct collisions with charged dust particles are calculated.

  7. Are large time differences in meteorite formation real. [cosmochronological dating and nucleosynthetic ratios

    NASA Technical Reports Server (NTRS)

    Cameron, A. G. W.

    1973-01-01

    Considerations are given concerning the interpretation of the results of two types of cosmochronological dating in order to examine the validity of the conclusions inferred from these results that the time intervals between the formation of various meteorite samples are very great. It is theorized that the isotopic differences between Angra dos Reis and other basaltic achondrites may be due to real fluctuations between the relative abundances of s-process and r-process nucleosynthesis products at a level delta about 0.001.

  8. Large eddy simulations of time-dependent and buoyancy-driven channel flows

    NASA Technical Reports Server (NTRS)

    Cabot, William H.

    1993-01-01

    The primary goal of this work has been to assess the performance of the dynamic SGS model in the large eddy simulation (LES) of channel flows in a variety of situations, viz., in temporal development of channel flow turned by a transverse pressure gradient and especially in buoyancy-driven turbulent flows such as Rayleigh-Benard and internally heated channel convection. For buoyancy-driven flows, there are additional buoyant terms that are possible in the base models, and one objective has been to determine if the dynamic SGS model results are sensitive to such terms. The ultimate goal is to determine the minimal base model needed in the dynamic SGS model to provide accurate results in flows with more complicated physical features. In addition, a program of direct numerical simulation (DNS) of fully compressible channel convection has been undertaken to determine stratification and compressibility effects. These simulations are intended to provide a comparative base for performing the LES of compressible (or highly stratified, pseudo-compressible) convection at high Reynolds number in the future.

  9. Time-gated ballistic imaging using a large aperture switching beam.

    PubMed

    Mathieu, Florian; Reddemann, Manuel A; Palmer, Johannes; Kneer, Reinhold

    2014-03-24

    Ballistic imaging commonly denotes the formation of line-of-sight shadowgraphs through turbid media by suppression of multiply scattered photons. The technique relies on a femtosecond laser acting as light source for the images and as switch for an optical Kerr gate that separates ballistic photons from multiply scattered ones. The achievable image resolution is one major limitation for the investigation of small objects. In this study, practical influences on the optical Kerr gate and image quality are discussed theoretically and experimentally applying a switching beam with large aperture (D = 19 mm). It is shown how switching pulse energy and synchronization of switching and imaging pulse in the Kerr cell influence the gate's transmission. Image quality of ballistic imaging and standard shadowgraphy is evaluated and compared, showing that the present ballistic imaging setup is advantageous for optical densities in the range of 8 < OD < 13. Owing to the spatial transmission characteristics of the optical Kerr gate, a rectangular aperture stop is formed, which leads to different resolution limits for vertical and horizontal structures in the object. Furthermore, it is reported how to convert the ballistic imaging setup into a schlieren-type system with an optical schlieren edge.

  10. Is now the time for molecular driven therapy for diffuse large B-cell lymphoma?

    PubMed

    Di Rocco, Alice; De Angelis, Federico; Ansuinelli, Michela; Foà, Robin; Martelli, Maurizio

    2017-09-01

    Recent genetic and molecular discoveries regarding alterations in diffuse large B-cell lymphoma (DLBCL) deeply changed the approach to this lymphoproliferative disorder. Novel additional predictors of outcomes and new therapeutic strategies are being introduced to improve outcomes. Areas covered: This review aims to analyse the recent molecular discoveries in DLBCL, the rationale of novel molecular driven treatments and their impact on DLBCL prognosis, especially in ABC-DLBCL and High Grade B Cell Lymphoma. Pre-clinical and clinical evidences are reviewed to critically evaluate the novel DLBCL management strategies. Expert commentary: New insights in DLBCL molecular characteristics should guide the therapeutic approach; the results of the current studies which are investigating safety and efficacy of novel 'X-RCHOP' will probably lead, in future, to a cell of origin (COO) based upfront therapy. Moreover, it is necessary to identify early patients with DLBCL who carried MYC, BCL2 and/or BCL6 rearrangements double hit lymphomas (DHL) because they should not receive standard R-CHOP but high intensity treatment as reported in many retrospective studies. New prospective trials are needed to investigate the more appropriate treatment of DHL.

  11. A reference web architecture and patterns for real-time visual analytics on large streaming data

    NASA Astrophysics Data System (ADS)

    Kandogan, Eser; Soroker, Danny; Rohall, Steven; Bak, Peter; van Ham, Frank; Lu, Jie; Ship, Harold-Jeffrey; Wang, Chun-Fu; Lai, Jennifer

    2013-12-01

    Monitoring and analysis of streaming data, such as social media, sensors, and news feeds, has become increasingly important for business and government. The volume and velocity of incoming data are key challenges. To effectively support monitoring and analysis, statistical and visual analytics techniques need to be seamlessly integrated; analytic techniques for a variety of data types (e.g., text, numerical) and scope (e.g., incremental, rolling-window, global) must be properly accommodated; interaction, collaboration, and coordination among several visualizations must be supported in an efficient manner; and the system should support the use of different analytics techniques in a pluggable manner. Especially in web-based environments, these requirements pose restrictions on the basic visual analytics architecture for streaming data. In this paper we report on our experience of building a reference web architecture for real-time visual analytics of streaming data, identify and discuss architectural patterns that address these challenges, and report on applying the reference architecture for real-time Twitter monitoring and analysis.

  12. Operational flood control of a low-lying delta system using large time step Model Predictive Control

    NASA Astrophysics Data System (ADS)

    Tian, Xin; van Overloop, Peter-Jules; Negenborn, Rudy R.; van de Giesen, Nick

    2015-01-01

    The safety of low-lying deltas is threatened not only by riverine flooding but by storm-induced coastal flooding as well. For the purpose of flood control, these deltas are mostly protected in a man-made environment, where dikes, dams and other adjustable infrastructures, such as gates, barriers and pumps are widely constructed. Instead of always reinforcing and heightening these structures, it is worth considering making the most of the existing infrastructure to reduce the damage and manage the delta in an operational and overall way. In this study, an advanced real-time control approach, Model Predictive Control, is proposed to operate these structures in the Dutch delta system (the Rhine-Meuse delta). The application covers non-linearity in the dynamic behavior of the water system and the structures. To deal with the non-linearity, a linearization scheme is applied which directly uses the gate height instead of the structure flow as the control variable. Given the fact that MPC needs to compute control actions in real-time, we address issues regarding computational time. A new large time step scheme is proposed in order to save computation time, in which different control variables can have different control time steps. Simulation experiments demonstrate that Model Predictive Control with the large time step setting is able to control a delta system better and much more efficiently than the conventional operational schemes.

  13. Poor construction, not time, takes its toll on subsidised fences designed to deter large carnivores.

    PubMed

    Frank, Jens; Eklund, Ann

    2017-01-01

    Large carnivore conservation may be considered as successful in Sweden, as wolf (Canis lupus), lynx (Lynx lynx), brown bear (Ursus arctos), golden eagles (Aquila chrysaetos), and wolverine (Gulo gulo) populations have recovered from extinction or near extinction to viable populations during the last three decades. Particularly the wolf and lynx populations have returned at the cost of an increasing number of carnivore attacks on domestic livestock. To support coexistence between carnivores and livestock production, the Swedish authorities subsidise interventions to prevent or reduce the number of carnivore attacks. The most commonly used intervention is carnivore deterring fencing, and all livestock owners can apply for subsidies to build a fence. To receive reimbursement the fence must be approved by the authorities according to predefined criteria. An important part of any management aiming to be adaptive is evaluating interventions. In this paper we evaluate to what extent previously subsidised fences still meet the criteria 1-15 years after their approval. Of 296 fences that had received subsidies in the county of Värmland, 100 randomly selected fences were revisited in 2016. From this subsample 14% of the fences still met the initial criteria for subsidies. None of the fences that still fulfilled the criteria were more than 8 years old, whereas fences with identified failures occurred in all age groups. Of the 86 fences that failed to meet the criteria, construction failures were the most commonly occurring problem. Maintenance failures, wear and tear, only explain a minor part of the failures. To improve the quality of fencing, as well as the quality and longevity of the subsidies programme, there is a need for improved communication between authorities, and improved communication and support from the authorities to livestock producers before and during construction of fences, as well as more rigorous inspection when the fences are built.

  14. Across Space and Time: Social Responses to Large-Scale Biophysical Systems

    NASA Astrophysics Data System (ADS)

    Macmynowski, Dena P.

    2007-06-01

    The conceptual rubric of ecosystem management has been widely discussed and deliberated in conservation biology, environmental policy, and land/resource management. In this paper, I argue that two critical aspects of the ecosystem management concept require greater attention in policy and practice. First, although emphasis has been placed on the “space” of systems, the “time”—or rates of change—associated with biophysical and social systems has received much less consideration. Second, discussions of ecosystem management have often neglected the temporal disconnects between changes in biophysical systems and the response of social systems to management issues and challenges. The empirical basis of these points is a case study of the “Crown of the Continent Ecosystem,” an international transboundary area of the Rocky Mountains that surrounds Glacier National Park (USA) and Waterton Lakes National Park (Canada). This project assessed the experiences and perspectives of 1) middle- and upper-level government managers responsible for interjurisdictional cooperation, and 2) environmental nongovernment organizations with an international focus. I identify and describe 10 key challenges to increasing the extent and intensity of transboundary cooperation in land/resource management policy and practice. These issues are discussed in terms of their political, institutional, cultural, information-based, and perceptual elements. Analytic techniques include a combination of environmental history, semistructured interviews with 48 actors, and text analysis in a systematic qualitative framework. The central conclusion of this work is that the rates of response of human social systems must be better integrated with the rates of ecological change. This challenge is equal to or greater than the well-recognized need to adapt the spatial scale of human institutions to large-scale ecosystem processes and transboundary wildlife.

  15. Verdict: Time-Dependent Density Functional Theory "Not Guilty" of Large Errors for Cyanines.

    PubMed

    Jacquemin, Denis; Zhao, Yan; Valero, Rosendo; Adamo, Carlo; Ciofini, Ilaria; Truhlar, Donald G

    2012-04-10

    We assess the accuracy of eight Minnesota density functionals (M05 through M08-SO) and two others (PBE and PBE0) for the prediction of electronic excitation energies of a family of four cyanine dyes. We find that time-dependent density functional theory (TDDFT) with the five most recent of these functionals (from M06-HF through M08-SO) is able to predict excitation energies for cyanine dyes within 0.10-0.36 eV accuracy with respect to the most accurate available Quantum Monte Carlo calculations, providing a comparable accuracy to the latest generation of CASPT2 calculations, which have errors of 0.16-0.34 eV. Therefore previous conclusions that TDDFT cannot treat cyanine dyes reasonably accurately must be revised.

  16. Reconciling transition path time and rate measurements in reactions with large entropic barriers

    NASA Astrophysics Data System (ADS)

    Makarov, Dmitrii E.

    2017-02-01

    Recent experiments and simulation studies showed that protein/DNA folding barriers inferred from folding rates or from potentials of mean force are often much higher than the barriers estimated from the distributions of transition path times. Here a toy model is used to explain a possible origin of this effect: It is shown that when the transition in question involves an entropic barrier, the one-dimensional Langevin model commonly used to interpret experimental data, while adequately predicting the transition rate, fails to describe the properties of the subset of the trajectories that form the transition path ensemble; the latter may still be describable in terms of a one-dimensional model, but with a different potential, just as observed experimentally.

  17. Reconciling transition path time and rate measurements in reactions with large entropic barriers.

    PubMed

    Makarov, Dmitrii E

    2017-02-21

    Recent experiments and simulation studies showed that protein/DNA folding barriers inferred from folding rates or from potentials of mean force are often much higher than the barriers estimated from the distributions of transition path times. Here a toy model is used to explain a possible origin of this effect: It is shown that when the transition in question involves an entropic barrier, the one-dimensional Langevin model commonly used to interpret experimental data, while adequately predicting the transition rate, fails to describe the properties of the subset of the trajectories that form the transition path ensemble; the latter may still be describable in terms of a one-dimensional model, but with a different potential, just as observed experimentally.

  18. Spin dynamics of close-in planets exhibiting large transit timing variations

    NASA Astrophysics Data System (ADS)

    Delisle, J.-B.; Correia, A. C. M.; Leleu, A.; Robutel, P.

    2017-09-01

    We study the spin evolution of close-in planets in compact multi-planetary systems. The rotation period of these planets is often assumed to be synchronous with the orbital period due to tidal dissipation. Here we show that planet-planet perturbations can drive the spin of these planets into non-synchronous or even chaotic states. In particular, we show that the transit timing variation (TTV) is a very good probe to study the spin dynamics, since both are dominated by the perturbations of the mean longitude of the planet. We apply our model to KOI-227 b and Kepler-88 b, which are both observed undergoing strong TTVs. We also perform numerical simulations of the spin evolution of these two planets. We show that for KOI-227 b non-synchronous rotation is possible, while for Kepler-88 b the rotation can be chaotic.

  19. Level of physical activity and screen time among Iranian children and adolescents at the national and provincial level: The CASPIAN-IV study

    PubMed Central

    Hovsepian, Silva; Kelishadi, Roya; Motlagh, Mohammad Esmaeil; Kasaeian, Amir; Shafiee, Gita; Arefirad, Tahereh; Najafi, Fereshteh; Khoramdad, Maliheh; Asayesh, Hamid; Heshmat, Ramin; Qorbani, Mostafa

    2016-01-01

    Background: There are few epidemiological reports on adherence to physical activity (PA) and screen-time (ST) recommendations among Iranian children and adolescents at the provincial level. We used nationally representative data to provide recent prevalence estimates of Iranian children who met the recommendations for PA and ST. Methods: This nationwide study was conducted among 14,880 students aged 6-18 years from 30 provinces of Iran. The frequency of the recommended level for PA (>1 hours/week) and ST (<2 hours/day) and different combinations of PA and ST was determined in the studied population. Results: In this study, 13,486 students (response rate: 90.6%) were studied. Overall, 18.62%, 34.11%, 50.66% and 9.63% of the students reported high ST, low level of PA, high TV watching and high computer working, respectively. The frequency of the recommended level of PA and ST was 53.92%. Of the studied population, 6.63% had low PA and high ST. Paradox combinations of low PA and low ST and moderate/high PA and high ST was prevalent among 27.47% and 6.26% of the children and adolescents. The lowest and highest frequency of recommended level of PA and ST was 38.9% and 65%, respectively. The lowest and highest frequency of low PA and high ST was 1.87% and 13.77%, respectively. Conclusion: The results of this study revealed that the frequency of low PA was high and that approximately 46% of the students did not meet the recommended level of PA and ST. The findings indicated that preparing facilities for improving PA level among children should be the main priority in our future interventions in this field. PMID:28210587

  20. Large-scale Hydrology Inferred From Grace Estimates of Time-variable Gravity

    NASA Astrophysics Data System (ADS)

    Swenson, S.; Wahr, J.; Milly, P. C. D.

    In recent years, a number of techniques for remotely sensing the Earth's surface have been developed, including active and passive radiometers, synthetic aperture radar, and radar and laser altimeters. These instruments have produced measurements of a wide range of phenomena at temporal and spatial scales that are not feasible by in-situ methods. Surface soil moisture, one of the principal components of terrestrial water storage, can be measured by microwave techniques; however, only the moisture in the top few centimeters of soil can be detected. Sub-surface soil moisture and groundwater are thus far undetectable by radiation based remote sensing techniques. Measurements of changes in surface gravity are indicative of changes in the sur- rounding water column. U.S. Geological Survey scientists use repeat surface gravity measurements to monitor groundwater recharge. Surface in-situ measurement is not a practical approach for water storage estimation at large length scales, because of the high spatial variability of terrestrial water storage. Satellite-based gravity mea- surement, however, promises to provide estimates of continental groundwater change, averaged over regions of a few hundred km and larger. The GRACE satellite mission, scheduled for launch at the end of 2001, is expected to deliver global estimates of the Earth's gravity field approximately every 30 days. After removing the effects of the at- mosphere and oceans, GRACE gravity solutions can be inverted to determine changes in continental water storage. We describe methods of extracting the water storage signal from simulated hydrolog- ical gravity solutions constructed using a land surface model based on monthly global precipitation records. Spatial averaging kernels were created to isolate the gravity sig- nal of individual drainage basins without contamination from surrounding hydrologi- cal or oceanic gravity signals. We then estimated the probable accuracy of averaging kernels for basins of

  1. Time-Encoded Thermal Neutron Imaging Using Large-Volume Pixelated CdZnTe Detectors

    NASA Astrophysics Data System (ADS)

    Brown, Steven T.

    CdZnTe detectors are commonly used for room-temperature gamma-ray spectroscopy and imaging in a variety of applications including nuclear security, nuclear medicine, and space science. The material's long-established sensitivity to thermal neutrons, however, is less utilized. Generally speaking, the performance of neutron detectors based on the Cd capture reaction is limited by the physical nature of the reaction itself. Multiple gamma rays are emitted promptly following each capture event, which consists of one realization of many possible combinations of gamma-ray lines. Although the gamma-ray cascade can reduce photopeak efficiency in conventional devices, this work demonstrates that pixelated CdZnTe can recover losses by reading out each gamma-ray interaction separately. Including coincident events, the measured 558-keV photopeak efficiency for a 3 x 3 array of 2 cm x 2 cm by 1.5 cm pixelated CdZnTe detectors was about 10%, i.e., ten 558 keV photopeak events per 100 incident thermal neutrons. This was in good agreement with its calculated value. Initial measurements also show that neutron-gamma discrimination beyond simple energy windowing is possible when incorporating the 3-D interaction locations of gamma rays provided by the pixelated readout. In this work, we developed and successfully demonstrated a proof-of-principle time-encoding system for thermal neutron imaging using pixelated CdZnTe. Time encoding was chosen because it is not limited by the detector's position resolution or spatial extent. These issues are exacerbated by Cd capture due to the dispersal of cascade gamma rays throughout the device. The system was first tested using a MURA-based, W-metal mask with both Co-57 and U-metal gamma-ray sources. About 0.3° angular resolution within a 22° field of view was achieved for gamma rays, and good image uniformity was observed for objects of moderate spatial extent. A MURA-based thermal neutron mask was then constructed using 1-mm-thick BN tiles

  2. Caterpillars selected for large body size and short development time are more susceptible to oxygen-related stress

    PubMed Central

    Harrison, Jon F; Cease, Arianne J; VandenBrooks, John M; Albert, Todd; Davidowitz, Goggy

    2013-01-01

    Recent studies suggest that higher growth rates may be associated with reduced capacities for stress tolerance and increased accumulated damage due to reactive oxygen species. We tested the response of Manduca sexta (Sphingidae) lines selected for large or small body size and short development time to hypoxia (10 kPa) and hyperoxia (25, 33, and 40 kPa); both hypoxia and hyperoxia reduce reproduction and oxygen levels over 33 kPa have been shown to increase oxidative damage in insects. Under normoxic (21 kPa) conditions, individuals from the large-selected (big-fast) line were larger and had faster growth rates, slightly longer developmental times, and reduced survival rates compared to individuals from a line selected for small size (small-fast) or an unselected control line. Individuals from the big-fast line exhibited greater negative responses to hyperoxia with greater reductions in juvenile and adult mass, growth rate, and survival than the other two lines. Hypoxia generally negatively affected survival and growth/size, but the lines responded similarly. These results are mostly consistent with the hypothesis that simultaneous acquisition of large body sizes and short development times leads to reduced capacities for coping with stressful conditions including oxidative damage. This result is of particular importance in that natural selection tends to decrease development time and increase body size. PMID:23762517

  3. Large-scale geometry and timing of the detachment systems in the Cyclades (Greece). Insight from Makronisos

    NASA Astrophysics Data System (ADS)

    Huet, Benjamin; Loisl, Johannes; Lindner, Karoline; Grasemann, Bernhard; Rice, A. Hugh N.; Soukis, Konstantinos; Schneider, David

    2013-04-01

    Characterizing the large-scale geometry of detachment zones and the timing of their movement is crucial to our overall understanding of the dynamics of metamorphic core complexes (MCCs). The Cyclades presents a world-class example of middle and lower crust that was exhumed below low angle detachments in such MCCs. They formed during Oligo-Miocene times in the stretched back-arc of the Hellenic subduction zone. Recently, regional correlations have emphasized the role of two large-scale detachment systems: the North Cycladic Detachment System (NCDS), running from Evia to Mykonos (at least) and the Western Cyclades Detachment System (WCDS) running from Serifos to Kea. Both detachment systems exhumed the Cycladic Blueschist unit and the basement unit below the Pelagonian. However, they are antithetic, with the NCDS having a top-NNE and the WCDS a top-SSW movement, and their timings are, in detail, different. Lithological and structural observations, together with radiochronologic and metamorphic constraints from the island of Makronisos allow us to bridge the gap between the Western Cyclades and Attica and prolongate the WCDS towards the NW, giving it an overall length of 90 km. Depending on the tectonostratigraphic position of Makronisos, which remains unclear, we propose two alternative scenarios for the large-scale geometry and dynamics of the WCDS. We also integrate our data within a model at the scale of the whole Cycladic realm and propose a mechanical explanation for the activity, location and timing of the major detachment systems.

  4. Real-time target detection technology of large view-field infrared image based on multicore DSP parallel processing

    NASA Astrophysics Data System (ADS)

    Sun, Gang; Liu, Songlin; Wang, Weihua; Chen, Zengping

    2013-10-01

    In order to implement real-time detection of hedgehopping target in large view-field infrared (LVIR) image, the paper proposes a fast algorithm flow to extract the target region of interest (ROI). The ground building region was rejected quickly and target ROI was segmented roughly through the background classification. Then the background image containing target ROI was matched with previous frame based on a mean removal normalized product correlation (MRNPC) similarity measure function. Finally, the target motion area was extracted by inter-frame difference in time domain. According to the proposed algorithm flow, this paper designs the high-speed real-time signal processing hardware platform based on FPGA + DSP, and also presents a new parallel processing strategy that called function-level and task-level, which could parallel process LVIR image by multi-core and multi-task. Experimental results show that the algorithm can extract low altitude aero target with complex background in large view effectively, and the new design hardware platform could implement real time processing of the IR image with 50000x288 pixels per second in large view-field infrared search system (LVIRSS).

  5. A mixed time integration method for large scale acoustic fluid-structure interaction

    SciTech Connect

    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.

  6. A new time dependent density functional algorithm for large systems and plasmons in metal clusters

    SciTech Connect

    Baseggio, Oscar; Fronzoni, Giovanna; Stener, Mauro

    2015-07-14

    A new algorithm to solve the Time Dependent Density Functional Theory (TDDFT) equations in the space of the density fitting auxiliary basis set has been developed and implemented. The method extracts the spectrum from the imaginary part of the polarizability at any given photon energy, avoiding the bottleneck of Davidson diagonalization. The original idea which made the present scheme very efficient consists in the simplification of the double sum over occupied-virtual pairs in the definition of the dielectric susceptibility, allowing an easy calculation of such matrix as a linear combination of constant matrices with photon energy dependent coefficients. The method has been applied to very different systems in nature and size (from H{sub 2} to [Au{sub 147}]{sup −}). In all cases, the maximum deviations found for the excitation energies with respect to the Amsterdam density functional code are below 0.2 eV. The new algorithm has the merit not only to calculate the spectrum at whichever photon energy but also to allow a deep analysis of the results, in terms of transition contribution maps, Jacob plasmon scaling factor, and induced density analysis, which have been all implemented.

  7. Multiscale simulation of time-dependent thermal transpiration in large-scale systems

    NASA Astrophysics Data System (ADS)

    Lockerby, Duncan A.; Patronis, Alexander; Borg, Matthew K.; Reese, Jason M.

    2014-11-01

    We describe the development of an efficient hybrid continuum-molecular approach for simulating non-isothermal, low-speed, internal rarefied gas flows, both in time and space. This is applied to transient flow in macro-scale Knudsen compressors, which is governed by both rarefied gas and continuum fluid dynamics. The method is an extension of the hybrid approach presented by Patronis et al. [J. Comp. Phys. 255, 558 (2013)], which is based on the framework originally proposed by Borg et al. [J. Comp. Phys. 233, 400 (2013)] for the simulation of micro/nano flows of high-aspect-ratio. The efficiency of the multiscale method allows the investigation of alternative Knudsen-compressor configurations to be undertaken. A comparison is made with published experimental data of the transient response (of pressure) in differentially heated reservoirs suddenly connected by a micro capillary. The multiscale simulation results compare very closely to the experimental data and are obtained at a fraction of the cost of a full kinetic or molecular solution. Recommendations for future development and opportunities are discussed. This work is financially supported in the UK by EPSRC Programme Grant EP/I011927/1 and EPSRC Grants EP/K038664/1 and EP/K038621/1.

  8. Energy beyond food: foraging theory informs time spent in thermals by a large soaring bird.

    PubMed

    Shepard, Emily L C; Lambertucci, Sergio A; Vallmitjana, Diego; Wilson, Rory P

    2011-01-01

    Current understanding of how animals search for and exploit food resources is based on microeconomic models. Although widely used to examine feeding, such constructs should inform other energy-harvesting situations where theoretical assumptions are met. In fact, some animals extract non-food forms of energy from the environment, such as birds that soar in updraughts. This study examined whether the gains in potential energy (altitude) followed efficiency-maximising predictions in the world's heaviest soaring bird, the Andean condor (Vultur gryphus). Animal-attached technology was used to record condor flight paths in three-dimensions. Tracks showed that time spent in patchy thermals was broadly consistent with a strategy to maximise the rate of potential energy gain. However, the rate of climb just prior to leaving a thermal increased with thermal strength and exit altitude. This suggests higher rates of energetic gain may not be advantageous where the resulting gain in altitude would lead to a reduction in the ability to search the ground for food. Consequently, soaring behaviour appeared to be modulated by the need to reconcile differing potential energy and food energy distributions. We suggest that foraging constructs may provide insight into the exploitation of non-food energy forms, and that non-food energy distributions may be more important in informing patterns of movement and residency over a range of scales than previously considered.

  9. Energy Beyond Food: Foraging Theory Informs Time Spent in Thermals by a Large Soaring Bird

    PubMed Central

    Shepard, Emily L. C.; Lambertucci, Sergio A.; Wilson, Rory P.

    2011-01-01

    Current understanding of how animals search for and exploit food resources is based on microeconomic models. Although widely used to examine feeding, such constructs should inform other energy-harvesting situations where theoretical assumptions are met. In fact, some animals extract non-food forms of energy from the environment, such as birds that soar in updraughts. This study examined whether the gains in potential energy (altitude) followed efficiency-maximising predictions in the world's heaviest soaring bird, the Andean condor (Vultur gryphus). Animal-attached technology was used to record condor flight paths in three-dimensions. Tracks showed that time spent in patchy thermals was broadly consistent with a strategy to maximise the rate of potential energy gain. However, the rate of climb just prior to leaving a thermal increased with thermal strength and exit altitude. This suggests higher rates of energetic gain may not be advantageous where the resulting gain in altitude would lead to a reduction in the ability to search the ground for food. Consequently, soaring behaviour appeared to be modulated by the need to reconcile differing potential energy and food energy distributions. We suggest that foraging constructs may provide insight into the exploitation of non-food energy forms, and that non-food energy distributions may be more important in informing patterns of movement and residency over a range of scales than previously considered. PMID:22087301

  10. A new time dependent density functional algorithm for large systems and plasmons in metal clusters

    NASA Astrophysics Data System (ADS)

    Baseggio, Oscar; Fronzoni, Giovanna; Stener, Mauro

    2015-07-01

    A new algorithm to solve the Time Dependent Density Functional Theory (TDDFT) equations in the space of the density fitting auxiliary basis set has been developed and implemented. The method extracts the spectrum from the imaginary part of the polarizability at any given photon energy, avoiding the bottleneck of Davidson diagonalization. The original idea which made the present scheme very efficient consists in the simplification of the double sum over occupied-virtual pairs in the definition of the dielectric susceptibility, allowing an easy calculation of such matrix as a linear combination of constant matrices with photon energy dependent coefficients. The method has been applied to very different systems in nature and size (from H2 to [Au147]-). In all cases, the maximum deviations found for the excitation energies with respect to the Amsterdam density functional code are below 0.2 eV. The new algorithm has the merit not only to calculate the spectrum at whichever photon energy but also to allow a deep analysis of the results, in terms of transition contribution maps, Jacob plasmon scaling factor, and induced density analysis, which have been all implemented.

  11. Long-term (17 Ma) turbidite record of the timing and frequency of large flank collapses of the Canary Islands

    NASA Astrophysics Data System (ADS)

    Hunt, J. E.; Talling, P. J.; Clare, M. A.; Jarvis, I.; Wynn, R. B.

    2014-08-01

    Volcaniclastic turbidites on the Madeira Abyssal Plain provide a record of large-volume volcanic island flank collapses from the Canary Islands. This long-term record spans 17 Ma, and comprises 125 volcaniclastic beds. Determining the timing, provenance and volumes of these turbidites provides key information about the occurrence of mass wasting from the Canary Islands, especially the western islands of Tenerife, La Palma and El Hierro. These turbidite records demonstrate that landslides often coincide with protracted periods of volcanic edifice growth, suggesting that loading of the volcanic edifices may be a key preconditioning factor for landslide triggers. Furthermore, the last large-volume failures from Tenerife coincide with explosive volcanism at the end of eruptive cycles. Many large-volume Canary Island landslides also occurred during periods of warmer and wetter climates associated with sea-level rise and subsequent highstand. However, these turbidites are not serially dependent and any association with climate or sea level change is not statistically significant.

  12. Large-scale climate variability and its effects on mean temperature and flowering time of Prunus and Betula in Denmark

    NASA Astrophysics Data System (ADS)

    Gormsen, A. K.; Hense, A.; Toldam-Andersen, T. B.; Braun, P.

    2005-08-01

    Large-scale climate variability largely affects average climatic conditions and therefore is likely to influence the phenology of plants. In NW-Europe, the North Atlantic Oscillation (NAO) particularly influences winter climate and, through climate interactions on plants, flowering time of all tree species. In Denmark, like in many other NW-European countries, flowering of most tree species has become earlier since the end of the 1980’s. To quantify a possible relation between NAO and flowering time of tree species, two sources of phenological information from the Copenhagen area (Denmark) were analysed, i.e. pollen counts of the genus Betula and observed first bloom dates of Prunus avium. The Winter NAO explained 29 and 37% of the variation of monthly mean temperature for February and March, respectively. The influence of temperature on flowering time was up to 56% to 60% for the February April mean. A direct correlation of Winter NAO-index and flowering time also revealed a clear relation but the time of influence was earlier (December to February). This was shown to be the likely result of a combination of direct and time-lagged effects of the NAO on air and sea surface temperature. The NAO signal is apparently stored in the North Sea and then influences temperature east up to the Baltic States. It is shown that Denmark is right in the centre of direct and time-lagged effects of the NAO. This offers the possibility of using the NAO-index for predicting flowering time of Prunus avium. The beginning of pollen flow appears to be influenced too much by short-term perturbations of the climate system decreasing the value of the NAO-index for prediction. However, it indicates a close relationship between natural climate variability, measured by the NAO index, and flowering time of tree species for Denmark.

  13. Dependence of b-value on Depth, Co-Seismic Slip, and Time for Large Magnitude Earthquakes

    NASA Astrophysics Data System (ADS)

    Aiken, J. M.; Uchide, T.; Schorlemmer, D.

    2016-12-01

    Spatial and temporal variations in parameters of earthquake sources and seismicity will be a key to understand the status of faults such as applied stress and fault strength and hence the potential of earthquake occurrence. Recent studies have shown that the b-value of the Gutenberg-Richter relationship decreases before large magnitude events for timescales of five years or more. In addition, large co-seismic slip values have been found to occur in extremely low b-value regions, e.g., the 2011 Tohoku-oki earthquake [Nanjo, et. al. 2012]. A comprehensive understanding requires us to explore the relationship between depth, co-seismic slip of a large earthquake, time, and b-value for large magnitude events occurring in different tectonic environments (oceanic and in-land). Here we present the relationship between co-seismic slip and b-values prior to several large magnitude events in Japan, e.g., the 2003 M8.3 Tokachi-oki earthquake near Hokkaido, using the Japan Meteorological Agency (JMA) earthquake catalog. We calculated the b-values at three-dimensionally distributed grids using the maximum likelihood estimation method and the reported JMA magnitude of completeness. We examined the cross section of depth, co-seismic slip, and time with the calculated b-values to investigate whether a common behavior exists prior to large events by comparing our results to the case of the 2011 Tohoku-oki earthquake, and consequently study what causes the change in b-value.

  14. Extending flood forecasting lead time in a large watershed by coupling WRF QPF with a distributed hydrological model

    NASA Astrophysics Data System (ADS)

    Li, Ji; Chen, Yangbo; Wang, Huanyu; Qin, Jianming; Li, Jie; Chiao, Sen

    2017-03-01

    Long lead time flood forecasting is very important for large watershed flood mitigation as it provides more time for flood warning and emergency responses. The latest numerical weather forecast model could provide 1-15-day quantitative precipitation forecasting products in grid format, and by coupling this product with a distributed hydrological model could produce long lead time watershed flood forecasting products. This paper studied the feasibility of coupling the Liuxihe model with the Weather Research and Forecasting quantitative precipitation forecast (WRF QPF) for large watershed flood forecasting in southern China. The QPF of WRF products has three lead times, including 24, 48 and 72 h, with the grid resolution being 20 km  × 20 km. The Liuxihe model is set up with freely downloaded terrain property; the model parameters were previously optimized with rain gauge observed precipitation, and re-optimized with the WRF QPF. Results show that the WRF QPF has bias with the rain gauge precipitation, and a post-processing method is proposed to post-process the WRF QPF products, which improves the flood forecasting capability. With model parameter re-optimization, the model's performance improves also. This suggests that the model parameters be optimized with QPF, not the rain gauge precipitation. With the increasing of lead time, the accuracy of the WRF QPF decreases, as does the flood forecasting capability. Flood forecasting products produced by coupling the Liuxihe model with the WRF QPF provide a good reference for large watershed flood warning due to its long lead time and rational results.

  15. Space time relationship in continuously moving table method for large FOV peripheral contrast-enhanced magnetic resonance angiography

    NASA Astrophysics Data System (ADS)

    Sabati, M.; Lauzon, M. L.; Frayne, R.

    2003-09-01

    Data acquisition using a continuously moving table approach is a method capable of generating large field-of-view (FOV) 3D MR angiograms. However, in order to obtain venous contamination-free contrast-enhanced (CE) MR angiograms in the lower limbs, one of the major challenges is to acquire all necessary k-space data during the restricted arterial phase of the contrast agent. Preliminary investigation on the space-time relationship of continuously acquired peripheral angiography is performed in this work. Deterministic and stochastic undersampled hybrid-space (x, ky, kz) acquisitions are simulated for large FOV peripheral runoff studies. Initial results show the possibility of acquiring isotropic large FOV images of the entire peripheral vascular system. An optimal trade-off between the spatial and temporal sampling properties was found that produced a high-spatial resolution peripheral CE-MR angiogram. The deterministic sampling pattern was capable of reconstructing the global structure of the peripheral arterial tree and showed slightly better global quantitative results than stochastic patterns. Optimal stochastic sampling patterns, on the other hand, enhanced small vessels and had more favourable local quantitative results. These simulations demonstrate the complex spatial-temporal relationship when sampling large FOV peripheral runoff studies. They also suggest that more investigation is required to maximize image quality as a function of hybrid-space coverage, acquisition repetition time and sampling pattern parameters.

  16. Space-time relationship in continuously moving table method for large FOV peripheral contrast-enhanced magnetic resonance angiography.

    PubMed

    Sabati, M; Lauzon, M L; Frayne, R

    2003-09-07

    Data acquisition using a continuously moving table approach is a method capable of generating large field-of-view (FOV) 3D MR angiograms. However, in order to obtain venous contamination-free contrast-enhanced (CE) MR angiograms in the lower limbs, one of the major challenges is to acquire all necessary k-space data during the restricted arterial phase of the contrast agent. Preliminary investigation on the space-time relationship of continuously acquired peripheral angiography is performed in this work. Deterministic and stochastic undersampled hybrid-space (x, k(y), k(z)) acquisitions are simulated for large FOV peripheral runoff studies. Initial results show the possibility of acquiring isotropic large FOV images of the entire peripheral vascular system. An optimal trade-off between the spatial and temporal sampling properties was found that produced a high-spatial resolution peripheral CE-MR angiogram. The deterministic sampling pattern was capable of reconstructing the global structure of the peripheral arterial tree and showed slightly better global quantitative results than stochastic patterns. Optimal stochastic sampling patterns, on the other hand, enhanced small vessels and had more favourable local quantitative results. These simulations demonstrate the complex spatial-temporal relationship when sampling large FOV peripheral runoff studies. They also suggest that more investigation is required to maximize image quality as a function of hybrid-space coverage, acquisition repetition time and sampling pattern parameters.

  17. Enhanced Design Alternative IV

    SciTech Connect

    N. E. Kramer

    1999-05-18

    This report evaluates Enhanced Design Alternative (EDA) IV as part of the second phase of the License Application Design Selection (LADS) effort. The EDA IV concept was compared to the VA reference design using criteria from the ''Design Input Request for LADS Phase II EDA Evaluations'' (CRWMS M&O 1999b) and (CRWMS M&O 1999f). Briefly, the EDA IV concept arranges the waste packages close together in an emplacement configuration known as ''line load''. Continuous pre-closure ventilation keeps the waste packages from exceeding the 350 C cladding and 200 C (4.3.13) drift wall temperature limits. This EDA concept keeps relatively high, uniform emplacement drift temperatures (post-closure) to drive water away from the repository and thus dry out the pillars between emplacement drifts. The waste package is shielded to permit human access to emplacement drifts and includes an integral filler inside the package to reduce the amount of water that can contact the waste form. Closure of the repository is desired 50 years after first waste is emplaced. Both backfill and a drip shields will be emplaced at closure to improve post-closure performance.

  18. A conceptual model for evolving run time support of mission and safety critical components in large, complex, distributed systems

    NASA Technical Reports Server (NTRS)

    Mckay, Charles W.

    1988-01-01

    Large, complex, distributed systems should be evolved to maximize life cycle support for non-stop operation of mission and safety critical components. This paper outlines the key issues and a recommended approach for tailoring a conceptual model of Ada run time support environments to meet the specific needs of such an application. Prerequisite concepts for this model have been described previously by this author and are summarized. This model proposes upward-compatible extensions to a previously published model of Ada run time environments from the ARTEWG (Ada Run Time Environment Working Group). The first model was used to identify Ada run time requirements, dependencies, issues, features, and options for single processor applications; however, the particular needs for distributed processing were not explicitly described. The purpose of this extended model is to address the needed systems software support for Ada application programs in distributed computing environments.

  19. Computer simulation of the thermal environment of large-scale integrated circuits - Computer time-saving techniques.

    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.

  20. Extending flood forecasting lead time in large basin by coupling bias-corrected WRF QPF with distributed hydrological model

    NASA Astrophysics Data System (ADS)

    LI, J.; Chen, Y.; Wang, H. Y.

    2016-12-01

    In large basin flood forecasting, the forecasting lead time is very important. Advances in numerical weather forecasting in the past decades provides new input to extend flood forecasting lead time in large rivers. Challenges for fulfilling this goal currently is that the uncertainty of QPF with these kinds of NWP models are still high, so controlling the uncertainty of QPF is an emerging technique requirement.The Weather Research and Forecasting (WRF) model is one of these NWPs, and how to control the QPF uncertainty of WRF is the research topic of many researchers among the meteorological community. In this study, the QPF products in the Liujiang river basin, a big river with a drainage area of 56,000 km2, was compared with the ground observation precipitation from a rain gauge networks firstly, and the results show that the uncertainty of the WRF QPF is relatively high. So a post-processed algorithm by correlating the QPF with the observed precipitation is proposed to remove the systematical bias in QPF. With this algorithm, the post-processed WRF QPF is close to the ground observed precipitation in area-averaged precipitation. Then the precipitation is coupled with the Liuxihe model, a physically based distributed hydrological model that is widely used in small watershed flash flood forecasting. The Liuxihe Model has the advantage with gridded precipitation from NWP and could optimize model parameters when there are some observed hydrological data even there is only a few, it also has very high model resolution to improve model performance, and runs on high performance supercomputer with parallel algorithm if executed in large rivers. Two flood events in the Liujiang River were collected, one was used to optimize the model parameters and another is used to validate the model. The results show that the river flow simulation has been improved largely, and could be used for real-time flood forecasting trail in extending flood forecasting leading time.

  1. Large-Time Behavior of GW Pollutant Plumes Subject to Biodegradation at the Fringe: Mathematical Analysis and its Application to a Large-Scale (~10 km) Field Problem

    NASA Astrophysics Data System (ADS)

    Chu, M. J.; Kitanidis, P. K.; McCarty, P. L.

    2003-12-01

    Engineered bioremediation and monitored natural attenuation are important options for the cleanup of frequently occurring subsurface contamination by organic compounds. Because the contaminant removal occurs only when the substrates, target contaminants, and degrading bacteria are present simultaneously, the controlling mixing processes of the contaminants and substrates dictate the contaminant removal rate. Due to the complex nature of subsurface environments, in-situ bioremediation often involves many physico-chemical and biological processes concurrently. Thus, mathematical modeling is a useful tool -and probably the only effective tool- to identify the rate controlling processes. As a tool for predicting the environmental impact of a spill and/or for screening the effectiveness of possible remediation technologies, its ability to correctly capture the key processes is important. However, classical modeling involving the discretized form of the governing equations over very large spatial domains and long periods is computationally infeasible at this point. In this research, we investigate the large-time solution behavior of a representative bio-reactive transport model assuming the mixing of two required substrates occurs only in the directions transverse to groundwater flow. The processes are governed by the commonly used advection-dispersion-reaction equations. The microbial growth and decay in the model are described by the double Monod kinetics terms and a linear decay term. The flow field is assumed to be uniform. We have developed a practical approach to estimate the size of the microbial reaction zone and the level of microbial concentration. We have found out that the microbial reaction rates are always limited by the transverse transport of the substrates at steady state, provided that the bulk substrate concentrations are much larger than a characteristic value determined only by the microbial kinetic parameters. Thus the reactions can be considered as

  2. Time-resolved diffuse reflectance measurement carried out on the head of an adult at large source-detector separation.

    PubMed

    Liebert, Adam; Sawosz, Piotr; Kacprzak, Michal; Weigl, Wojciech; Botwicz, Marcin; Maniewski, Roman

    2010-01-01

    Multichannel time-resolved optical monitoring system was constructed for measurements of diffuse reflectance in optically turbid medium at very large source-detector separation up to 9 cm. The system is based on femtosecond TiSa laser and sensitive photomultiplier tube detector. The laser light of 300mW of power was delivered to the surface of the head with the use of an optical fiber. A beam expander was applied in order to distribute the laser light on a large spot which allowed to avoid energetic stimulation of the tissue. The photomultiplier tube detector was positioned directly on the surface of the medium at the distance of 9cm from the center of the source position. In this paper we report results of an in-vivo experiment carried out on the head of an adult healthy volunteer. The time-resolved system was applied during intravenous injection of an optical contrast agent (indocyanine green - ICG) and the distributions of times of flight of photons were successfully acquired showing inflow and washout of the dye to the tissue. Time-courses of the moments of distributions of times of flight of photons are presented and compared with the results obtained simultaneously at shorter source-detector separations (3 cm, 4 cm and 5 cm).

  3. High-order implicit residual smoothing time scheme for direct and large eddy simulations of compressible flows

    NASA Astrophysics Data System (ADS)

    Cinnella, P.; Content, C.

    2016-12-01

    Restrictions on the maximum allowable time step of explicit time integration methods for direct and large eddy simulations of compressible turbulent flows at high Reynolds numbers can be very severe, because of the extremely small space steps used close to solid walls to capture tiny and elongated boundary layer structures. A way of increasing stability limits is to use implicit time integration schemes. However, the price to pay is a higher computational cost per time step, higher discretization errors and lower parallel scalability. In quest for an implicit time scheme for scale-resolving simulations providing the best possible compromise between these opposite requirements, we develop a Runge-Kutta implicit residual smoothing (IRS) scheme of fourth-order accuracy, based on a bilaplacian operator. The implicit operator involves the inversion of scalar pentadiagonal systems, for which efficient parallel algorithms are available. The proposed method is assessed against two explicit and two implicit time integration techniques in terms of computational cost required to achieve a threshold level of accuracy. Precisely, the proposed time scheme is compared to four-stages and six-stages low-storage Runge-Kutta method, to the second-order IRS and to a second-order backward scheme solved by means of matrix-free quasi-exact Newton subiterations. Numerical results show that the proposed IRS scheme leads to reductions in computational time by a factor 3 to 5 for an accuracy comparable to that of the corresponding explicit Runge-Kutta scheme.

  4. The Berkeley SETI program - SERENDIP IV instrumentation

    NASA Astrophysics Data System (ADS)

    Werthimer, Dan; Bowyer, Stuart; Ng, David; Donnelly, Charles; Cobb, Jeff; Lampton, Michael; Airieau, Sabine

    1997-01-01

    We discuss the hardware design of SERENDIP IV, which will be deployed in early 1997 for a 21-cm sky survey at the National Astronomy and Ionospheric Center's 305-m radio telescope in Arecibo, Puerto Rico. SERENDIP IV is a 167 million channel spectrum analyzer, covering a 100-Mhz bandwidth, with 0.6-Hz resolution and a 1.7-s integration time. SERENDIP IV's modular design incorporates a bank of digital mixers and filters to separate the 100 MHz band into 40 2.5 MHz subbands. Each 2.5 MHz subband is further broken down into 0.6 Hz bins by means of a four million point fast Fourier transform. The resulting power spectra are analyzed by 40 high-speed processors. Narrowband signals having power significantly above background noise levels are recorded along with telescope coordinates, time, and frequency. The data are sent in real time to Berkeley for analysis.

  5. Volume-Time Relations in Large Silicic Volcanic Fields - Clues to a Thermomechanical Control on Eruption Frequency and Mechanism

    NASA Astrophysics Data System (ADS)

    de Silva, S. L.

    2005-05-01

    In assessing the hazard associated with large calderas it is crucial that the broader context of the formation, evolution, and eruption of these systems be factored into any assessment. The existing paradigm is that as large volumes of intermediate to silicic magma accumulate and evolve at high-level, a pressure build-up during second boiling results in overpressures of 20 - 25 MPa that result in the fracture of the magma chamber roof and consequent eruption. This may not be the case for the largest ignimbrite eruptions. These are typically associated with a regional ignimbrite flare-up and we should consider a more holistic approach that takes into account the spatiotemporal and volume-time evolution of the entire flare-up in understanding the operation of these systems. I illustrate this with a case study of the Altiplano-Puna Volcanic Complex of the Central Andes (APVC). The timing, pattern, and volumes of ignimbrite volcanism in the APVC reveal: 1) Pulsing of the ignimbrite eruptions with an approximate two million year period; 2) A trend to larger volume eruptions climaxing at about 4 Ma; 3) Migration and focusing of activity toward the central part of the APVC with time; and 4) Markedly diminished activity since 4 Ma. These observations suggest that the ignimbrite flare-up is result of progressive thermal (and mechanical) maturation of the crustal column due to intrusion and batholith formation and attendant effects on lithosphere strength. The progressive erosion of crustal strength results in failure of the crust and catastrophic eruption. Examination of available data from other large silicic volcanic provinces through space and time reveal a general pattern similar to that shown by the APVC. This suggests a consistency of process consisting of thermal preparation, catastrophic response, and relaxation in the development of these large volcanic fields. The possibility that the largest ignimbrite eruptions (>1000 km3) are triggered by mechanical failure of

  6. Stage IV-S neuroblastoma. Results with definitive therapy

    SciTech Connect

    Stokes, S.H.; Thomas, P.R.; Perez, C.A.; Vietti, T.J.

    1984-05-15

    The results of management of 14 patients with Stage IV-S neuroblastoma are reported. The treatment policy, although not consistent over this time span, in general used a combination of radiotherapy and chemotherapy or infrequently one modality alone. Twelve of 14 (86%) survived more than 6 years. One patient, with a solitary mediastinal primary tumor, died of rapidly progressive disease at three months. The other death occurred in a 4.5-year-old presenting with hepatomegaly at diagnosis followed by skeletal dissemination 2.5 years later. Thirteen of the patients were younger than 1 year of age. Of the 11 patients that received radiotherapy, 4 experienced mild asymptomatic scoliosis or kyphoscoliosis at 3 to 12 years after initial therapy. A review of the literature indicates that spontaneous regression in this tumor is very frequent; therefore, it is recommended that for the common presentation of massive hepatomegaly in an infant, close observation is warranted, unless life threatening complications occur. However, initial therapeutic intervention may be indicated in those patients with life threatening presentations. This data did not substantiate the necessity for complete surgical excision of the primary tumor, as has been suggested by others.

  7. Magnitude and timing of annual maximum floods: Trends and large-scale climatic associations for the Blacksmith Fork River, Utah

    NASA Astrophysics Data System (ADS)

    Jain, Shaleen; Lall, Upmanu

    2000-12-01

    The magnitude and timing of spring snowmelt floods reflects seasonal snow accumulation and spring temperature patterns. Consequently, interannual variations in regions such as the intermountain West, with snowmelt annual maximum floods, may be related to low-frequency variations in winter/spring large-scale climate variability. Changes in the seasonality of basin precipitation and temperature consequent to slow changes in the baseline climate state (e.g., owing to natural climate variations and/or potential global warming trends) may have significant impacts on such floods. A case study of the Blacksmith Fork River in northern Utah that explores such a hypothesis is presented here. Trends and associations in the magnitude and timing of annual maximum floods are documented, their impact on time-varying estimates of the 100 year flood is assessed, and relationships with known large-scale, quasi-oscillatory patterns of climate variability are explored. Evidence for structured low-frequency variation in flood timing and magnitude and its relation to winter/spring precipitation and temperature and to tropical (El Niño- Southern Oscillation) and extratropical (Pacific Decadal Oscillation) Pacific climate precursors is presented. Mechanisms for these ocean-atmosphere teleconnections to basin precipitation, temperature, and flood potential are discussed.

  8. Correcting C IV-based virial black hole masses

    NASA Astrophysics Data System (ADS)

    Coatman, Liam; Hewett, Paul C.; Banerji, Manda; Richards, Gordon T.; Hennawi, Joseph F.; Prochaska, J. Xavier

    2017-02-01

    The C IVλλ1498,1501 broad emission line is visible in optical spectra to redshifts exceeding z ∼ 5. C IV has long been known to exhibit significant displacements to the blue and these 'blueshifts' almost certainly signal the presence of strong outflows. As a consequence, single-epoch virial black hole (BH) mass estimates derived from C IV velocity widths are known to be systematically biased compared to masses from the hydrogen Balmer lines. Using a large sample of 230 high-luminosity (LBol = 1045.5-1048 erg s-1), redshift 1.5 < z < 4.0 quasars with both C IV and Balmer line spectra, we have quantified the bias in C IV BH masses as a function of the C IV blueshift. C IV BH masses are shown to be a factor of 5 larger than the corresponding Balmer-line masses at C IV blueshifts of 3000 km s-1and are overestimated by almost an order of magnitude at the most extreme blueshifts, ≳5000 km s-1. Using the monotonically increasing relationship between the C IV blueshift and the mass ratio BH(C IV)/BH(Hα), we derive an empirical correction to all C IV BH masses. The scatter between the corrected C IV masses and the Balmer masses is 0.24 dex at low C IV blueshifts (∼0 km s-1) and just 0.10 dex at high blueshifts (∼3000 km s-1), compared to 0.40 dex before the correction. The correction depends only on the C IV line properties - i.e. full width at half-maximum and blueshift - and can therefore be applied to all quasars where C IV emission line properties have been measured, enabling the derivation of unbiased virial BH-mass estimates for the majority of high-luminosity, high-redshift, spectroscopically confirmed quasars in the literature.

  9. Large-scale time-lapse microscopy of Oct4 expression in human embryonic stem cell colonies.

    PubMed

    Bhadriraju, Kiran; Halter, Michael; Amelot, Julien; Bajcsy, Peter; Chalfoun, Joe; Vandecreme, Antoine; Mallon, Barbara S; Park, Kye-Yoon; Sista, Subhash; Elliott, John T; Plant, Anne L

    2016-07-01

    Identification and quantification of the characteristics of stem cell preparations is critical for understanding stem cell biology and for the development and manufacturing of stem cell based therapies. We have developed image analysis and visualization software that allows effective use of time-lapse microscopy to provide spatial and dynamic information from large numbers of human embryonic stem cell colonies. To achieve statistically relevant sampling, we examined >680 colonies from 3 different preparations of cells over 5days each, generating a total experimental dataset of 0.9 terabyte (TB). The 0.5 Giga-pixel images at each time point were represented by multi-resolution pyramids and visualized using the Deep Zoom Javascript library extended to support viewing Giga-pixel images over time and extracting data on individual colonies. We present a methodology that enables quantification of variations in nominally-identical preparations and between colonies, correlation of colony characteristics with Oct4 expression, and identification of rare events.

  10. Parallel Configuration For Fast Superconducting Strip Line Detectors With Very Large Area In Time Of Flight Mass Spectrometry

    SciTech Connect

    Casaburi, A.; Zen, N.; Suzuki, K.; Ohkubo, M.; Ejrnaes, M.; Cristiano, R.; Pagano, S.

    2009-12-16

    We realized a very fast and large Superconducting Strip Line Detector based on a parallel configuration of nanowires. The detector with size 200x200 {mu}m{sup 2} recorded a sub-nanosecond pulse width of 700 ps in FWHM (400 ps rise time and 530 ps relaxation time) for lysozyme monomers/multimers molecules accelerated at 175 keV in a Time of Flight Mass Spectrometer. This record is the best in the class of superconducting detectors and comparable with the fastest NbN superconducting single photon detector of 10x10 {mu}m{sup 2}. We succeeded in acquiring mass spectra as the first step for a scale-up to {approx}mm pixel size for high throughput MS analysis, while keeping a fast response.

  11. Application of Time Series Insar Technique for Deformation Monitoring of Large-Scale Landslides in Mountainous Areas of Western China

    NASA Astrophysics Data System (ADS)

    Qu, T.; Lu, P.; Liu, C.; Wan, H.

    2016-06-01

    Western China is very susceptible to landslide hazards. As a result, landslide detection and early warning are of great importance. This work employs the SBAS (Small Baseline Subset) InSAR Technique for detection and monitoring of large-scale landslides that occurred in Li County, Sichuan Province, Western China. The time series INSAR is performed using descending scenes acquired from TerraSAR-X StripMap mode since 2014 to get the spatial distribution of surface displacements of this giant landslide. The time series results identify the distinct deformation zone on the landslide body with a rate of up to 150mm/yr. The deformation acquired by SBAS technique is validated by inclinometers from diverse boreholes of in-situ monitoring. The integration of InSAR time series displacements and ground-based monitoring data helps to provide reliable data support for the forecasting and monitoring of largescale landslide.

  12. Precisions Measurement for the Grasp of Welding Deformation amount of Time Series for Large-Scale Industrial Products

    NASA Astrophysics Data System (ADS)

    Abe, R.; Hamada, K.; Hirata, N.; Tamura, R.; Nishi, N.

    2015-05-01

    As well as the BIM of quality management in the construction industry, demand for quality management of the manufacturing process of the member is higher in shipbuilding field. The time series of three-dimensional deformation of the each process, and are accurately be grasped strongly demanded. In this study, we focused on the shipbuilding field, will be examined three-dimensional measurement method. The shipyard, since a large equipment and components are intricately arranged in a limited space, the installation of the measuring equipment and the target is limited. There is also the element to be measured is moved in each process, the establishment of the reference point for time series comparison is necessary to devise. In this paper will be discussed method for measuring the welding deformation in time series by using a total station. In particular, by using a plurality of measurement data obtained from this approach and evaluated the amount of deformation of each process.

  13. Comparison of Fault Detection Algorithms for Real-time Diagnosis in Large-Scale System. Appendix E

    NASA Technical Reports Server (NTRS)

    Kirubarajan, Thiagalingam; Malepati, Venkat; Deb, Somnath; Ying, Jie

    2001-01-01

    In this paper, we present a review of different real-time capable algorithms to detect and isolate component failures in large-scale systems in the presence of inaccurate test results. A sequence of imperfect test results (as a row vector of I's and O's) are available to the algorithms. In this case, the problem is to recover the uncorrupted test result vector and match it to one of the rows in the test dictionary, which in turn will isolate the faults. In order to recover the uncorrupted test result vector, one needs the accuracy of each test. That is, its detection and false alarm probabilities are required. In this problem, their true values are not known and, therefore, have to be estimated online. Other major aspects in this problem are the large-scale nature and the real-time capability requirement. Test dictionaries of sizes up to 1000 x 1000 are to be handled. That is, results from 1000 tests measuring the state of 1000 components are available. However, at any time, only 10-20% of the test results are available. Then, the objective becomes the real-time fault diagnosis using incomplete and inaccurate test results with online estimation of test accuracies. It should also be noted that the test accuracies can vary with time --- one needs a mechanism to update them after processing each test result vector. Using Qualtech's TEAMS-RT (system simulation and real-time diagnosis tool), we test the performances of 1) TEAMSAT's built-in diagnosis algorithm, 2) Hamming distance based diagnosis, 3) Maximum Likelihood based diagnosis, and 4) HidderMarkov Model based diagnosis.

  14. Robust Requirements Tracing via Internet Search Technology: Improving an IV and V Technique. Phase 2

    NASA Technical Reports Server (NTRS)

    Hayes, Jane; Dekhtyar, Alex

    2004-01-01

    There are three major objectives to this phase of the work. (1) Improvement of Information Retrieval (IR) methods for Independent Verification and Validation (IV&V) requirements tracing. Information Retrieval methods are typically developed for very large (order of millions - tens of millions and more documents) document collections and therefore, most successfully used methods somewhat sacrifice precision and recall in order to achieve efficiency. At the same time typical IR systems treat all user queries as independent of each other and assume that relevance of documents to queries is subjective for each user. The IV&V requirements tracing problem has a much smaller data set to operate on, even for large software development projects; the set of queries is predetermined by the high-level specification document and individual requirements considered as query input to IR methods are not necessarily independent from each other. Namely, knowledge about the links for one requirement may be helpful in determining the links of another requirement. Finally, while the final decision on the exact form of the traceability matrix still belongs to the IV&V analyst, his/her decisions are much less arbitrary than those of an Internet search engine user. All this suggests that the information available to us in the framework of the IV&V tracing problem can be successfully leveraged to enhance standard IR techniques, which in turn would lead to increased recall and precision. We developed several new methods during Phase II; (2) IV&V requirements tracing IR toolkit. Based on the methods developed in Phase I and their improvements developed in Phase II, we built a toolkit of IR methods for IV&V requirements tracing. The toolkit has been integrated, at the data level, with SAIC's SuperTracePlus (STP) tool; (3) Toolkit testing. We tested the methods included in the IV&V requirements tracing IR toolkit on a number of projects.

  15. Structural dynamic testing of the Engineering Test Satellite-IV

    NASA Astrophysics Data System (ADS)

    Shiraki, K.; Mitsuma, H.; Matsushita, T.; Izumi, H.

    The Engineering Test Satellite-IV (ETS-IV) was the first large scale spacecraft developed and launched successfully in Japan on a new N-II launch vehicle. This paper presents an approach taken for the structural development of the ETS-IV. Extensive structural tests were performed to demonstrate that the ETS-IV spacecraft meets all design requirements and will survive all critical environments. Details of the static load test, vibration tests, acoustic test, and pyrotechnic shock test were described. The test results were compared with analyses and measured flight data.

  16. PMD IVS Analysis Center

    NASA Technical Reports Server (NTRS)

    Tornatore, Vincenza

    2013-01-01

    The main activities carried out at the PMD (Politecnico di Milano DIIAR) IVS Analysis Center during 2012 are briefly higlighted, and future plans for 2013 are sketched out. We principally continued to process European VLBI sessions using different approaches to evaluate possible differences due to various processing choices. Then VLBI solutions were also compared to the GPS ones as well as the ones calculated at co-located sites. Concerning the observational aspect, several tests were performed to identify the most suitable method to achieve the highest possible accuracy in the determination of GNSS (GLOBAL NAVIGATION SATELLITE SYSTEM) satellite positions using the VLBI technique.

  17. Large Observatory for x-ray Timing (LOFT-P): a Probe-class mission concept study

    NASA Astrophysics Data System (ADS)

    Wilson-Hodge, Colleen A.; Ray, Paul S.; Chakrabarty, Deepto; Feroci, Marco; Alvarez, Laura; Baysinger, Michael; Becker, Chris; Bozzo, Enrico; Brandt, Soren; Carson, Billy; Chapman, Jack; Dominguez, Alexandra; Fabisinski, Leo; Gangl, Bert; Garcia, Jay; Griffith, Christopher; Hernanz, Margarita; Hickman, Robert; Hopkins, Randall; Hui, Michelle; Ingram, Luster; Jenke, Peter; Korpela, Seppo; Maccarone, Tom; Michalska, Malgorzata; Pohl, Martin; Santangelo, Andrea; Schanne, Stephane; Schnell, Andrew; Stella, Luigi; van der Klis, Michiel; Watts, Anna; Winter, Berend; Zane, Silvia

    2016-07-01

    LOFT-P is a mission concept for a NASA Astrophysics Probe-Class (<$1B) X-ray timing mission, based on the LOFT M-class concept originally proposed to ESAs M3 and M4 calls. LOFT-P requires very large collecting area, high time resolution, good spectral resolution, broad-band spectral coverage (2-30 keV), highly flexible scheduling, and an ability to detect and respond promptly to time-critical targets of opportunity. It addresses science questions such as: What is the equation of state of ultra dense matter? What are the effects of strong gravity on matter spiraling into black holes? It would be optimized for sub-millisecond timing of bright Galactic X-ray sources including X-ray bursters, black hole binaries, and magnetars to study phenomena at the natural timescales of neutron star surfaces and black hole event horizons and to measure mass and spin of black holes. These measurements are synergistic to imaging and high-resolution spectroscopy instruments, addressing much smaller distance scales than are possible without very long baseline X-ray interferometry, and using complementary techniques to address the geometry and dynamics of emission regions. LOFT-P would have an effective area of >6 m2, > 10x that of the highly successful Rossi X-ray Timing Explorer (RXTE). A sky monitor (2-50 keV) acts as a trigger for pointed observations, providing high duty cycle, high time resolution monitoring of the X-ray sky with 20 times the sensitivity of the RXTE All-Sky Monitor, enabling multi-wavelength and multimessenger studies. A probe-class mission concept would employ lightweight collimator technology and large-area solid-state detectors, segmented into pixels or strips, technologies which have been recently greatly advanced during the ESA M3 Phase A study of LOFT. Given the large community interested in LOFT (>800 supporters*, the scientific productivity of this mission is expected to be very high, similar to or greater than RXTE ( 2000 refereed publications). We

  18. Drosophila neurexin IV interacts with Roundabout and is required for repulsive midline axon guidance.

    PubMed

    Banerjee, Swati; Blauth, Kevin; Peters, Kimberly; Rogers, Stephen L; Fanning, Alan S; Bhat, Manzoor A

    2010-04-21

    Slit/Roundabout (Robo) signaling controls midline repulsive axon guidance. However, proteins that interact with Slit/Robo at the cell surface remain largely uncharacterized. Here, we report that the Drosophila transmembrane septate junction-specific protein Neurexin IV (Nrx IV) functions in midline repulsive axon guidance. Nrx IV is expressed in the neurons of the developing ventral nerve cord, and nrx IV mutants show crossing and circling of ipsilateral axons and fused commissures. Interestingly, the axon guidance defects observed in nrx IV mutants seem independent of its other binding partners, such as Contactin and Neuroglian and the midline glia protein Wrapper, which interacts in trans with Nrx IV. nrx IV mutants show diffuse Robo localization, and dose-dependent genetic interactions between nrx IV/robo and nrx IV/slit indicate that they function in a common pathway. In vivo biochemical studies reveal that Nrx IV associates with Robo, Slit, and Syndecan, and interactions between Robo and Slit, or Nrx IV and Slit, are affected in nrx IV and robo mutants, respectively. Coexpression of Nrx IV and Robo in mammalian cells confirms that these proteins retain the ability to interact in a heterologous system. Furthermore, we demonstrate that the extracellular region of Nrx IV is sufficient to rescue Robo localization and axon guidance phenotypes in nrx IV mutants. Together, our studies establish that Nrx IV is essential for proper Robo localization and identify Nrx IV as a novel interacting partner of the Slit/Robo signaling pathway.

  19. Large-scale frequency- and time-domain quantum entanglement over the optical frequency comb (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Pfister, Olivier

    2017-05-01

    When it comes to practical quantum computing, the two main challenges are circumventing decoherence (devastating quantum errors due to interactions with the environmental bath) and achieving scalability (as many qubits as needed for a real-life, game-changing computation). We show that using, in lieu of qubits, the "qumodes" represented by the resonant fields of the quantum optical frequency comb of an optical parametric oscillator allows one to create bona fide, large scale quantum computing processors, pre-entangled in a cluster state. We detail our recent demonstration of 60-qumode entanglement (out of an estimated 3000) and present an extension to combining this frequency-tagged with time-tagged entanglement, in order to generate an arbitrarily large, universal quantum computing processor.

  20. Scaling up the dissemination of evidence-based mental health practice to large systems and long-term time frames.

    PubMed

    Resnick, Sandra G; Rosenheck, Robert A

    2009-05-01

    This Open Forum raises issues related to large-scale dissemination of sustainable evidence-based practices. Current dissemination efforts have been time limited and primarily conducted at volunteer sites with the skills of external expert trainers. The authors describe an effort to implement supported employment at 166 veterans programs in what is hoped to be a permanent addition to mental health services offered by the Department of Veterans Affairs. A two-stage process is described for developing a cadre of internal trainers who can realize the goals of this large-scale dissemination effort. Such strategies appear necessary to fully realize the broad national changes envisioned in the New Freedom Commission report.

  1. 3-D imaging of large scale buried structure by 1-D inversion of very early time electromagnetic (VETEM) data

    USGS Publications Warehouse

    Aydmer, A.A.; Chew, W.C.; Cui, T.J.; Wright, D.L.; Smith, D.V.; Abraham, J.D.

    2001-01-01

    A simple and efficient method for large scale three-dimensional (3-D) subsurface imaging of inhomogeneous background is presented. One-dimensional (1-D) multifrequency distorted Born iterative method (DBIM) is employed in the inversion. Simulation results utilizing synthetic scattering data are given. Calibration of the very early time electromagnetic (VETEM) experimental waveforms is detailed along with major problems encountered in practice and their solutions. This discussion is followed by the results of a large scale application of the method to the experimental data provided by the VETEM system of the U.S. Geological Survey. The method is shown to have a computational complexity that is promising for on-site inversion.

  2. Polymerization of Pu(IV) in aqueous nitric acid solutions

    SciTech Connect

    Toth, L.M.; Friedman, H.A.; Osborne, M.M.

    1980-10-01

    The polymerization of Pu(IV) in aqueous nitric acid solutions has been studied spectrophotometrically both to establish the influence of large UO{sub 2}(NO{sub 3}){sub 2} concentrations on the polymerization rates and, more generally, to review the influence of the major parameters on the polymer reaction. Typically, experiments have been performed at 50{sup 0}C and with 0.05 M Pu in nitric acid solutions that vary in acidity from 0.07 to 0.4 M. An induction period usually precedes the polymer growth stage during which time nucleation of primary hydrolysis products occurs. Uranyl nitrate retards the polymerization reaction by approximately 35% in spite of the counteracting influence of the nitrate ions associated with this solute. The rate of polymer formation, expressed as d(percent polymer)/dt, has been shown to depend on the total plutonium concentration in reactions where the Pu(IV) concentration remained constant; and it is therefore suggested that the polymer reaction rate is not first order with respect to the concentration of plutonium as was previously thought. It has been shown further that accurate acid determinations on stock reagents are essential in order to obtain reliable polymerization experiments. Satisfactory procedures for these analyses did not exist, so appropriate modifications to the iodate precipitation methods were developed. The most ideal plutonium reagent material has been shown to be crystalline Pu(IV) nitrate because it can be added directly to acid solutions without the occurrence of unintentional hydrolysis reactions.

  3. NAVIS-An UGV Indoor Positioning System Using Laser Scan Matching for Large-Area Real-Time Applications

    PubMed Central

    Tang, Jian.; Chen, Yuwei.; Jaakkola, Anttoni.; Liu, Jinbing.; Hyyppä, Juha.; Hyyppä, Hannu.

    2014-01-01

    Laser scan matching with grid-based maps is a promising tool for real-time indoor positioning of mobile Unmanned Ground Vehicles (UGVs). While there are critical implementation problems, such as the ability to estimate the position by sensing the unknown indoor environment with sufficient accuracy and low enough latency for stable vehicle control, further development work is necessary. Unfortunately, most of the existing methods employ heuristics for quick positioning in which numerous accumulated errors easily lead to loss of positioning accuracy. This severely restricts its applications in large areas and over lengthy periods of time. This paper introduces an efficient real-time mobile UGV indoor positioning system for large-area applications using laser scan matching with an improved probabilistically-motivated Maximum Likelihood Estimation (IMLE) algorithm, which is based on a multi-resolution patch-divided grid likelihood map. Compared with traditional methods, the improvements embodied in IMLE include: (a) Iterative Closed Point (ICP) preprocessing, which adaptively decreases the search scope; (b) a totally brute search matching method on multi-resolution map layers, based on the likelihood value between current laser scan and the grid map within refined search scope, adopted to obtain the global optimum position at each scan matching; and (c) a patch-divided likelihood map supporting a large indoor area. A UGV platform called NAVIS was designed, manufactured, and tested based on a low-cost robot integrating a LiDAR and an odometer sensor to verify the IMLE algorithm. A series of experiments based on simulated data and field tests with NAVIS proved that the proposed IMEL algorithm is a better way to perform local scan matching that can offer a quick and stable positioning solution with high accuracy so it can be part of a large area localization/mapping, application. The NAVIS platform can reach an updating rate of 12 Hz in a feature-rich environment and 2 Hz

  4. NAVIS-An UGV indoor positioning system using laser scan matching for large-area real-time applications.

    PubMed

    Tang, Jian; Chen, Yuwei; Jaakkola, Anttoni; Liu, Jinbing; Hyyppä, Juha; Hyyppä, Hannu

    2014-07-04

    Laser scan matching with grid-based maps is a promising tool for real-time indoor positioning of mobile Unmanned Ground Vehicles (UGVs). While there are critical implementation problems, such as the ability to estimate the position by sensing the unknown indoor environment with sufficient accuracy and low enough latency for stable vehicle control, further development work is necessary. Unfortunately, most of the existing methods employ heuristics for quick positioning in which numerous accumulated errors easily lead to loss of positioning accuracy. This severely restricts its applications in large areas and over lengthy periods of time. This paper introduces an efficient real-time mobile UGV indoor positioning system for large-area applications using laser scan matching with an improved probabilistically-motivated Maximum Likelihood Estimation (IMLE) algorithm, which is based on a multi-resolution patch-divided grid likelihood map. Compared with traditional methods, the improvements embodied in IMLE include: (a) Iterative Closed Point (ICP) preprocessing, which adaptively decreases the search scope; (b) a totally brute search matching method on multi-resolution map layers, based on the likelihood value between current laser scan and the grid map within refined search scope, adopted to obtain the global optimum position at each scan matching; and (c) a patch-divided likelihood map supporting a large indoor area. A UGV platform called NAVIS was designed, manufactured, and tested based on a low-cost robot integrating a LiDAR and an odometer sensor to verify the IMLE algorithm. A series of experiments based on simulated data and field tests with NAVIS proved that the proposed IMEL algorithm is a better way to perform local scan matching that can offer a quick and stable positioning solution with high accuracy so it can be part of a large area localization/mapping, application. The NAVIS platform can reach an updating rate of 12 Hz in a feature-rich environment and 2 Hz

  5. Real-time simulation of nonequilibrium transport of magnetization in large open quantum spin systems driven by dissipation

    NASA Astrophysics Data System (ADS)

    Banerjee, D.; Hebenstreit, F.; Jiang, F.-J.; Wiese, U.-J.

    2015-09-01

    Using quantum Monte Carlo, we study the nonequilibrium transport of magnetization in large open strongly correlated quantum spin-1/2 systems driven by purely dissipative processes that conserve the uniform or staggered magnetization, disregarding unitary Hamiltonian dynamics. We prepare both a low-temperature Heisenberg ferromagnet and an antiferromagnet in two parts of the system that are initially isolated from each other. We then bring the two subsystems in contact and study their real-time dissipative dynamics for different geometries. The flow of the uniform or staggered magnetization from one part of the system to the other is described by a diffusion equation that can be derived analytically.

  6. Fast analysis of wide-band scattering from electrically large targets with time-domain parabolic equation method

    NASA Astrophysics Data System (ADS)

    He, Zi; Chen, Ru-Shan

    2016-03-01

    An efficient three-dimensional time domain parabolic equation (TDPE) method is proposed to fast analyze the narrow-angle wideband EM scattering properties of electrically large targets. The finite difference (FD) of Crank-Nicolson (CN) scheme is used as the traditional tool to solve the time-domain parabolic equation. However, a huge computational resource is required when the meshes become dense. Therefore, the alternating direction implicit (ADI) scheme is introduced to discretize the time-domain parabolic equation. In this way, the reduced transient scattered fields can be calculated line by line in each transverse plane for any time step with unconditional stability. As a result, less computational resources are required for the proposed ADI-based TDPE method when compared with both the traditional CN-based TDPE method and the finite-different time-domain (FDTD) method. By employing the rotating TDPE method, the complete bistatic RCS can be obtained with encouraging accuracy for any observed angle. Numerical examples are given to demonstrate the accuracy and efficiency of the proposed method.

  7. The effects of season, daylight saving and time of sunrise on serum cortisol in a large population.

    PubMed

    Hadlow, Narelle C; Brown, Suzanne; Wardrop, Robert; Henley, David

    2014-03-01

    Cortisol is critical for maintenance of health and homeostasis and factors affecting cortisol levels are of clinical importance. There is conflicting information about the effects of season on morning cortisol and little information on the effects of sunlight on population cortisol assessment. The aim of this study was to assess whether changes in median serum cortisol occurred in a population in conjunction with changing seasons, daylight saving time (DST) or time of sunrise. We analysed serum cortisol results (n = 27,569) from a single large laboratory over a 13-year period. Subjects with confounding medications or medical conditions were excluded and data analysed in 15-minute intervals. We assessed the influence of traditional seasons, seasons determined by equinox/solstice, DST and time of sunrise on median cortisol. The median time of cortisol collection did not vary significantly between seasons. Using traditional seasons, median cortisol was lowest in summer (386 nmol/L) and spring (384 nmol/L) with higher cortisol in autumn (406 nmol/L) and winter (414 nmol/L). Median cortisol was lowest in the summer solstice quarter with significant comparative increases in the spring equinox quarter (3.1%), the autumn equinox quarter (4.5%) and the winter solstice quarter (8.6%). When cortisol was modelled against time, with adjustment for actual sunrise time on day of collection, for each hour delay in sunrise there was a 4.8% increase in median cortisol (95% CI: 3.9-5.7%). In modelling to explain the variation in cortisol over the morning, sunrise time was better than season in explaining seasonal effects. A subtle cyclic pattern in median cortisol also occurred throughout the months of the year. A 3-year trial of DST allowed comparison of cortisol in DST and non DST periods, when clock time differed by one hour. There was modest evidence of a difference in acrophase between DST and non DST cortisol (p = 0.038), with DST peak cortisol estimated to

  8. CHANG-ES. IV. RADIO CONTINUUM EMISSION OF 35 EDGE-ON GALAXIES OBSERVED WITH THE KARL G. JANSKY VERY LARGE ARRAY IN D CONFIGURATION—DATA RELEASE 1

    SciTech Connect

    Wiegert, Theresa; Irwin, Judith; MacGregor, Stephen E-mail: irwin@astro.queensu.ca; and others

    2015-09-15

    We present the first part of the observations made for the Continuum Halos in Nearby Galaxies, an EVLA Survey (CHANG-ES) project. The aim of the CHANG-ES project is to study and characterize the nature of radio halos, their prevalence as well as their magnetic fields, and the cosmic rays illuminating these fields. This paper reports observations with the compact D configuration of the Karl G. Jansky Very Large Array (VLA) for the sample of 35 nearby edge-on galaxies of CHANG-ES. With the new wide bandwidth capabilities of the VLA, an unprecedented sensitivity was achieved for all polarization products. The beam resolution is an average of 9.″6 and 36″ with noise levels reaching approximately 6 and 30 μJy beam{sup −1} for C- and L-bands, respectively (robust weighting). We present intensity maps in these two frequency bands (C and L), with different weightings, as well as spectral index maps, polarization maps, and new measurements of star formation rates (SFRs). The data products described herein are available to the public in the CHANG-ES data release available at http://www.queensu.ca/changes. We also present evidence of a trend among galaxies with larger halos having higher SFR surface density, and we show, for the first time, a radio continuum image of the median galaxy, taking advantage of the collective signal-to-noise ratio of 30 of our galaxies. This image shows clearly that a “typical” spiral galaxy is surrounded by a halo of magnetic fields and cosmic rays.

  9. Results of analysis of human impact on environment using the time series of vegetation satellite images around large industrial centers

    NASA Astrophysics Data System (ADS)

    Shevyrnogov, A.; Vysotskaya, G.; Sukhinin, A.; Frolikova, O.; Tchernetsky, M.

    The paper shows the efficiency of an application of the vegetation index image time series to determine long-term vegetation dynamics. The influence of large industrial centers of Siberia on the near-by vegetation is demonstrated. The analysis of the data shows that the influence of industrial waste is stronger in the Siberian North. These regions are characterized by critical conditions for vegetation existence. In the south of the Krasnoyarsk region, human impact is also important, but the possibility of vegetation self-rehabilitation is higher. The present-day economic situation in Russia is unique, with a temporary abrupt fall of industrial production and its following increase. Thus, we managed to analyze the degree of human impact on the environment within a relatively short-time interval.

  10. Combined electrochemical, heat generation, and thermal model for large prismatic lithium-ion batteries in real-time applications

    NASA Astrophysics Data System (ADS)

    Farag, Mohammed; Sweity, Haitham; Fleckenstein, Matthias; Habibi, Saeid

    2017-08-01

    Real-time prediction of the battery's core temperature and terminal voltage is very crucial for an accurate battery management system. In this paper, a combined electrochemical, heat generation, and thermal model is developed for large prismatic cells. The proposed model consists of three sub-models, an electrochemical model, heat generation model, and thermal model which are coupled together in an iterative fashion through physicochemical temperature dependent parameters. The proposed parameterization cycles identify the sub-models' parameters separately by exciting the battery under isothermal and non-isothermal operating conditions. The proposed combined model structure shows accurate terminal voltage and core temperature prediction at various operating conditions while maintaining a simple mathematical structure, making it ideal for real-time BMS applications. Finally, the model is validated against both isothermal and non-isothermal drive cycles, covering a broad range of C-rates, and temperature ranges [-25 °C to 45 °C].

  11. An explicit large time step particle-in-cell scheme for nonlinear gyrokinetic simulations in the electromagnetic regime

    NASA Astrophysics Data System (ADS)

    Kleiber, R.; Hatzky, R.; Könies, A.; Mishchenko, A.; Sonnendrücker, E.

    2016-03-01

    A new algorithm for electromagnetic gyrokinetic simulations, the so called "pullback transformation scheme" proposed by Mishchenko et al. [Phys. Plasmas 21, 092110 (2014)] is motivated as an explicit time integrator reset after each full timestep and investigated in detail. Using a numerical dispersion relation valid in slab geometry, it is shown that the linear properties of the scheme are comparable to those of an implicit v∥ -scheme. A nonlinear extension of the mixed variable formulation, derived consistently from a field Lagrangian, is proposed. The scheme shows excellent numerical properties with a low statistical noise level and a large time step especially for MHD modes. The example of a nonlinear slab tearing mode simulation is used to illustrate the properties of different formulations of the physical model equations.

  12. Motions of charged particles in the Magnetosphere under the influence of a time-varying large scale convection electric field

    NASA Technical Reports Server (NTRS)

    Smith, P. H.; Bewtra, N. K.; Hoffman, R. A.

    1979-01-01

    The motions of charged particles under the influence of the geomagnetic and electric fields were quite complex in the region of the inner magnetosphere. The Volland-Stern type large scale convection electric field was used successfully to predict both the plasmapause location and particle enhancements determined from Explorer 45 measurements. A time dependence in this electric field was introduced based on the variation in Kp for actual magnetic storm conditions. The particle trajectories were computed as they change in this time-varying electric field. Several storm fronts of particles of different magnetic moments were allowed to be injected into the inner magnetosphere from L = 10 in the equatorial plane. The motions of these fronts are presented in a movie format.

  13. Discrete-time neural network for fast solving large linear L1 estimation problems and its application to image restoration.

    PubMed

    Xia, Youshen; Sun, Changyin; Zheng, Wei Xing

    2012-05-01

    There is growing interest in solving linear L1 estimation problems for sparsity of the solution and robustness against non-Gaussian noise. This paper proposes a discrete-time neural network which can calculate large linear L1 estimation problems fast. The proposed neural network has a fixed computational step length and is proved to be globally convergent to an optimal solution. Then, the proposed neural network is efficiently applied to image restoration. Numerical results show that the proposed neural network is not only efficient in solving degenerate problems resulting from the nonunique solutions of the linear L1 estimation problems but also needs much less computational time than the related algorithms in solving both linear L1 estimation and image restoration problems.

  14. High-energy radiation from thunderstorms and lightning with the Large Observatory for x-ray Timing (LOFT) mission

    NASA Astrophysics Data System (ADS)

    Marisaldi, Martino; Smith, David M.; Brandt, Søren; Briggs, Michael S.; Budz-Jørgensen, Carl; Campana, Riccardo; Carlson, Brant E.; Celestin, Sebastien; Connaughton, Valerie; Cummer, Steven A.; Dwyer, Joseph R.; Fishman, Gerald J.; Fullekrug, Martin; Fuschino, Fabio; Gjesteland, Thomas; Neubert, Torsten; Østgaard, Nikolai; Tavani, Marco

    2015-04-01

    We explore the possible contributions of the Large Observatory for X-ray Timing (LOFT) mission to the study of high-energy radiation from thunderstorms and lightning. LOFT is a mission dedicated to X-ray timing studies of astrophysical sources, characterised by a very large effective area of about 8.5 square meters at 8 keV. Although the main scientific target of the mission is the fundamental physics of matter under extreme conditions, the peculiar instrument concept allows significant contributions to a wide range of other science topics, including the cross-disciplinary field of high-energy atmospheric physics, at the crossroad between geophysics, space physics and astrophysics. In this field we foresee the following major contributions: detect ˜ 700 Terrestrial Gamma-ray Flashes (TGFs) per year, probing the TGF intensity distribution at low fluence values and providing an unbiased sample of bright events thanks to the intrinsic robustness against dead-time and pile-up; provide the largest TGF detection rate surface density above the equator, allowing for correlation studies with lightning activity on short time scales and small regional scales, to probe the TGF / lightning relationship; lower by a factor ˜ 5 the minimum detectable fluence for Terrestrial Electron Beams (TEBs), an additional tool to probe TGF production mechanism and the lower edge of TGF intensity distribution; open up a discovery space for the detection of high-altitude electron beams and weak X-ray emissions associated to Transient Luminous Events (TLEs). LOFT has been studied as a candidate ESA M3 mission during an extensive assessment phase. The high level of readiness and maturity of the mission, as well as the clean and solid assessment of its unique science case, make LOFT a competitive mission with a compelling science case. For this reason, its development has been continued, aiming at new launch opportunities.

  15. Development of a time-stepping sediment budget model for assessing land use impacts in large river basins.

    PubMed

    Wilkinson, S N; Dougall, C; Kinsey-Henderson, A E; Searle, R D; Ellis, R J; Bartley, R

    2014-01-15

    The use of river basin modelling to guide mitigation of non-point source pollution of wetlands, estuaries and coastal waters has become widespread. To assess and simulate the impacts of alternate land use or climate scenarios on river washload requires modelling techniques that represent sediment sources and transport at the time scales of system response. Building on the mean-annual SedNet model, we propose a new D-SedNet model which constructs daily budgets of fine sediment sources, transport and deposition for each link in a river network. Erosion rates (hillslope, gully and streambank erosion) and fine sediment sinks (floodplains and reservoirs) are disaggregated from mean annual rates based on daily rainfall and runoff. The model is evaluated in the Burdekin basin in tropical Australia, where policy targets have been set for reducing sediment and nutrient loads to the Great Barrier Reef (GBR) lagoon from grazing and cropping land. D-SedNet predicted annual loads with similar performance to that of a sediment rating curve calibrated to monitored suspended sediment concentrations. Relative to a 22-year reference load time series at the basin outlet derived from a dynamic general additive model based on monitoring data, D-SedNet had a median absolute error of 68% compared with 112% for the rating curve. RMS error was slightly higher for D-SedNet than for the rating curve due to large relative errors on small loads in several drought years. This accuracy is similar to existing agricultural system models used in arable or humid environments. Predicted river loads were sensitive to ground vegetation cover. We conclude that the river network sediment budget model provides some capacity for predicting load time-series independent of monitoring data in ungauged basins, and for evaluating the impact of land management on river sediment load time-series, which is challenging across large regions in data-poor environments.

  16. IV access in bleeding trauma patients: a performance review.

    PubMed

    Engels, Paul T; Passos, Edward; Beckett, Andrew N; Doyle, Jeffrey D; Tien, Homer C

    2014-01-01

    Exsanguinating haemorrhage is a leading cause of death in severely injured trauma patients. Management includes achieving haemostasis, replacing lost intravascular volume with fluids and blood, and treating coagulopathy. The provision of fluids and blood products is contingent on obtaining adequate vascular access to the patient's venous system. We sought to examine the nature and timing of achieving adequate intravenous (IV) access in trauma patients requiring uncrossmatched blood in the trauma bay. We performed a retrospective chart review of all patients admitted to our trauma centre from 2005 to 2009 who were transfused uncrossmatched blood in the trauma bay. We examined the impact of IV access on prehospital times and time to first PRBC transfusion. Of 208 study patients, 168 (81%) received prehospital IV access, and the on-scene time for these patients was 5 min longer (16.1 vs 11.4, p<0.01). Time to achieving adequate IV access in those without any prehospital IVs occurred on average 21 min (6.6-30.5) after arrival to the trauma bay. A central venous catheter was placed in 92 (44%) of patients. Time to first blood transfusion correlated most strongly with time to achieving central venous access (Pearson correlation coefficient 0.94, p<0.001) as opposed to time to achieving adequate peripheral IV access (Pearson correlation coefficient 0.19, p=0.12). We found that most bleeding patients received a prehospital IV; however, we also found that obtaining prehospital IVs was associated with longer EMS on-scene times and longer prehospital times. Interestingly, we found that obtaining a prehospital IV was not associated with more rapid initiation of blood product transfusion. Obtaining optimal IV access and subsequent blood transfusion in severely injured patients continues to present a challenge. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Linear time reduction of large kinetic mechanisms with directed relation graph: n-Heptane and iso-octane

    SciTech Connect

    Lu, Tianfeng; Law, Chung K.

    2006-01-01

    The algorithm of directed relation graph recently developed for skeletal mechanism reduction was extended to overall linear time operation, thereby greatly facilitating the computational effort in mechanism reduction, particularly for those involving large mechanisms. Together with a two-stage reduction strategy and using the kinetic responses of autoignition and perfectly stirred reactor (PSR) with extensive parametric variations as the criteria in eliminating unimportant species, a detailed 561-species n-heptane mechanism and a detailed 857-species iso-octane mechanism were successfully reduced to skeletal mechanisms consisting of 188 and 233 species, respectively. These skeletal mechanisms were demonstrated to mimic well the performance of the detailed mechanisms, not only for the autoignition and PSR systems based on which the reduced mechanisms were developed but also for the independent system of jet-stirred reactor. It was further observed that the accuracy of calculated species concentrations was equivalently bounded by the user-specified error threshold value and that the reduction time for a single reaction state is only about 50 ms for the large iso-octane mechanism.

  18. Stabilization of large drainage basins over geological time scales: Cenozoic West Africa, hot spot swell growth, and the Niger River

    NASA Astrophysics Data System (ADS)

    Chardon, Dominique; Grimaud, Jean-Louis; Rouby, Delphine; Beauvais, Anicet; Christophoul, Frédéric

    2016-03-01

    Reconstructing the evolving geometry of large river catchments over geological time scales is crucial to constraining yields to sedimentary basins. In the case of Africa, it should further help deciphering the response of large cratonic sediment routing systems to Cenozoic growth of the basin-and-swell topography of the continent. Mapping of dated and regionally correlated lateritic paleolandscape remnants complemented by onshore sedimentological archives allows the reconstruction of two physiographic configurations of West Africa in the Paleogene. Those reconstructions show that the geometry of the drainage is stabilized by the late early Oligocene (29 Ma) and probably by the end of the Eocene (34 Ma), allowing to effectively link the inland morphoclimatic record to offshore sedimentation since that time, particularly in the case of the Niger catchment—delta system. Mid-Eocene paleogeography reveals the antiquity of the Senegambia catchment back to at least 45 Ma and suggests that a marginal upwarp forming a continental divide preexisted early Oligocene connection of the Niger and Volta catchments to the Equatorial Atlantic Ocean. Such a drainage rearrangement was primarily enhanced by the topographic growth of the Hoggar hot spot swell and caused a stratigraphic turnover along the Equatorial margin of West Africa.

  19. Massive Cloud Computing Processing of P-SBAS Time Series for Displacement Analyses at Large Spatial Scale

    NASA Astrophysics Data System (ADS)

    Casu, F.; de Luca, C.; Lanari, R.; Manunta, M.; Zinno, I.

    2016-12-01

    A methodology for computing surface deformation time series and mean velocity maps of large areas is presented. Our approach relies on the availability of a multi-temporal set of Synthetic Aperture Radar (SAR) data collected from ascending and descending orbits over an area of interest, and also permits to estimate the vertical and horizontal (East-West) displacement components of the Earth's surface. The adopted methodology is based on an advanced Cloud Computing implementation of the Differential SAR Interferometry (DInSAR) Parallel Small Baseline Subset (P-SBAS) processing chain which allows the unsupervised processing of large SAR data volumes, from the raw data (level-0) imagery up to the generation of DInSAR time series and maps. The presented solution, which is highly scalable, has been tested on the ascending and descending ENVISAT SAR archives, which have been acquired over a large area of Southern California (US) that extends for about 90.000 km2. Such an input dataset has been processed in parallel by exploiting 280 computing nodes of the Amazon Web Services Cloud environment. Moreover, to produce the final mean deformation velocity maps of the vertical and East-West displacement components of the whole investigated area, we took also advantage of the information available from external GPS measurements that permit to account for possible regional trends not easily detectable by DInSAR and to refer the P-SBAS measurements to an external geodetic datum. The presented results clearly demonstrate the effectiveness of the proposed approach that paves the way to the extensive use of the available ERS and ENVISAT SAR data archives. Furthermore, the proposed methodology can be particularly suitable to deal with the very huge data flow provided by the Sentinel-1 constellation, thus permitting to extend the DInSAR analyses at a nearly global scale. This work is partially supported by: the DPC-CNR agreement, the EPOS-IP project and the ESA GEP project.

  20. A new method for determining the long-period component of the source time function of large earthquakes

    SciTech Connect

    Zhang, Jiajun; Lay, T. )

    1989-04-01

    Inversions of seismic body waves indicate that most large earthquakes involve spatial and temporal heterogeneity of the moment release, but seismic body waves usually lack sufficient bandwidth to constrain the long-period component of the radiation. Analysis of long-period surface waves and free oscillations can constrain the overall source duration and moment; however, most procedures assume simple trapezoidal or boxcar source-time histories, inconsistent with the body wave complexity. The authors find that source-time function complexity can affect long-period surface waves sufficiently to impact estimates of the source moment tensor, rupture duration and centroid depth. They present a procedure to objectively determine the long-period component of complex source-time functions in which they directly utilize results from body wave analysis. The method is applied to two great normal fault events of June 22, 1977 (Tonga, M{sub w} = 8.2) and August 19, 1977 (Indonesia, M{sub w} = 8.5). Standard long period analysis procedures underestimate the total slip duration in both cases. The overall source process times of both earthquakes are longer than 120 s.