12. Detail, typical window with fireproof shutters open, northeast rear, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. Detail, typical window with fireproof shutters open, northeast rear, view to southwest, 135mm lens. Note cracks evidencing structural failure. - Benicia Arsenal, Powder Magazine No. 5, Junction of Interstate Highways 680 & 780, Benicia, Solano County, CA

Characterization of Window Functions for Regularization of Electrical Capacitance Tomography Image Reconstruction

NASA Astrophysics Data System (ADS)

Jiang, Peng; Peng, Lihui; Xiao, Deyun

2007-06-01

This paper presents a regularization method by using different window functions as regularization for electrical capacitance tomography (ECT) image reconstruction. Image reconstruction for ECT is a typical ill-posed inverse problem. Because of the small singular values of the sensitivity matrix, the solution is sensitive to the measurement noise. The proposed method uses the spectral filtering properties of different window functions to make the solution stable by suppressing the noise in measurements. The window functions, such as the Hanning window, the cosine window and so on, are modified for ECT image reconstruction. Simulations with respect to five typical permittivity distributions are carried out. The reconstructions are better and some of the contours are clearer than the results from the Tikhonov regularization. Numerical results show that the feasibility of the image reconstruction algorithm using different window functions as regularization.

Quantifying nonergodicity in nonautonomous dissipative dynamical systems: An application to climate change

NASA Astrophysics Data System (ADS)

Drótos, Gábor; Bódai, Tamás; Tél, Tamás

2016-08-01

In nonautonomous dynamical systems, like in climate dynamics, an ensemble of trajectories initiated in the remote past defines a unique probability distribution, the natural measure of a snapshot attractor, for any instant of time, but this distribution typically changes in time. In cases with an aperiodic driving, temporal averages taken along a single trajectory would differ from the corresponding ensemble averages even in the infinite-time limit: ergodicity does not hold. It is worth considering this difference, which we call the nonergodic mismatch, by taking time windows of finite length for temporal averaging. We point out that the probability distribution of the nonergodic mismatch is qualitatively different in ergodic and nonergodic cases: its average is zero and typically nonzero, respectively. A main conclusion is that the difference of the average from zero, which we call the bias, is a useful measure of nonergodicity, for any window length. In contrast, the standard deviation of the nonergodic mismatch, which characterizes the spread between different realizations, exhibits a power-law decrease with increasing window length in both ergodic and nonergodic cases, and this implies that temporal and ensemble averages differ in dynamical systems with finite window lengths. It is the average modulus of the nonergodic mismatch, which we call the ergodicity deficit, that represents the expected deviation from fulfilling the equality of temporal and ensemble averages. As an important finding, we demonstrate that the ergodicity deficit cannot be reduced arbitrarily in nonergodic systems. We illustrate via a conceptual climate model that the nonergodic framework may be useful in Earth system dynamics, within which we propose the measure of nonergodicity, i.e., the bias, as an order-parameter-like quantifier of climate change.

Neurophysiology of Speech Differences in Childhood Apraxia of Speech

PubMed Central

Preston, Jonathan L.; Molfese, Peter J.; Gumkowski, Nina; Sorcinelli, Andrea; Harwood, Vanessa; Irwin, Julia; Landi, Nicole

2014-01-01

Event-related potentials (ERPs) were recorded during a picture naming task of simple and complex words in children with typical speech and with childhood apraxia of speech (CAS). Results reveal reduced amplitude prior to speaking complex (multisyllabic) words relative to simple (monosyllabic) words for the CAS group over the right hemisphere during a time window thought to reflect phonological encoding of word forms. Group differences were also observed prior to production of spoken tokens regardless of word complexity during a time window just prior to speech onset (thought to reflect motor planning/programming). Results suggest differences in pre-speech neurolinguistic processes. PMID:25090016

Evaluation of sliding window correlation performance for characterizing dynamic functional connectivity and brain states

PubMed Central

Shakil, Sadia; Lee, Chin-Hui; Keilholz, Shella Dawn

2016-01-01

A promising recent development in the study of brain function is the dynamic analysis of resting-state functional MRI scans, which can enhance understanding of normal cognition and alterations that result from brain disorders. One widely used method of capturing the dynamics of functional connectivity is sliding window correlation (SWC). However, in the absence of a “gold standard” for comparison, evaluating the performance of the SWC in typical resting-state data is challenging. This study uses simulated networks (SNs) with known transitions to examine the effects of parameters such as window length, window offset, window type, noise, filtering, and sampling rate on the SWC performance. The SWC time course was calculated for all node pairs of each SN and then clustered using the k-means algorithm to determine how resulting brain states match known configurations and transitions in the SNs. The outcomes show that the detection of state transitions and durations in the SWC is most strongly influenced by the window length and offset, followed by noise and filtering parameters. The effect of the image sampling rate was relatively insignificant. Tapered windows provide less sensitivity to state transitions than rectangular windows, which could be the result of the sharp transitions in the SNs. Overall, the SWC gave poor estimates of correlation for each brain state. Clustering based on the SWC time course did not reliably reflect the underlying state transitions unless the window length was comparable to the state duration, highlighting the need for new adaptive window analysis techniques. PMID:26952197

20. TYPICAL VIEW OF FRONT WINDOWS FROM 4TH TO 9TH ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

20. TYPICAL VIEW OF FRONT WINDOWS FROM 4TH TO 9TH FLOOR WITH WHITE GLAZED TERRA COTTA SILL AND HEADERS. MULLIONS ARE ORANGE BROWN BRICKS LIKE THE WALLS. BRICKS ARE IN FLEMISH BOND PATTERN. - Pacific Telephone & Telegraph Company Building, 1519 Franklin Street, Oakland, Alameda County, CA

Mode switching in volcanic seismicity: El Hierro 2011-2013

NASA Astrophysics Data System (ADS)

Roberts, Nick S.; Bell, Andrew F.; Main, Ian G.

2016-05-01

The Gutenberg-Richter b value is commonly used in volcanic eruption forecasting to infer material or mechanical properties from earthquake distributions. Such studies typically analyze discrete time windows or phases, but the choice of such windows is subjective and can introduce significant bias. Here we minimize this sample bias by iteratively sampling catalogs with randomly chosen windows and then stack the resulting probability density functions for the estimated b>˜ value to determine a net probability density function. We examine data from the El Hierro seismic catalog during a period of unrest in 2011-2013 and demonstrate clear multimodal behavior. Individual modes are relatively stable in time, but the most probable b>˜ value intermittently switches between modes, one of which is similar to that of tectonic seismicity. Multimodality is primarily associated with intermittent activation and cessation of activity in different parts of the volcanic system rather than with respect to any systematic inferred underlying process.

40 CFR 745.63 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., but not limited to, certain window, floor, and stair surfaces. Impact surface means an interior or.... Interior window sill means the portion of the horizontal window ledge that protrudes into the interior of... based on the equation [60+(3*100)+(4*110)]/(1+3+4). Window trough means, for a typical double-hung...

Micromirror-based manipulation of synchrotron x-ray beams

NASA Astrophysics Data System (ADS)

Walko, D. A.; Chen, Pice; Jung, I. W.; Lopez, D.; Schwartz, C. P.; Shenoy, G. K.; Wang, Jin

2017-08-01

Synchrotron beamlines typically use macroscopic, quasi-static optics to manipulate x-ray beams. We present the use of dynamic microelectromechanical systems-based optics (MEMS) to temporally modulate synchrotron x-ray beams. We demonstrate this concept using single-crystal torsional MEMS micromirrors oscillating at frequencies of 75 kHz. Such a MEMS micromirror, with lateral dimensions of a few hundred micrometers, can interact with x rays by operating in grazing-incidence reflection geometry; x rays are deflected only when an x-ray pulse is incident on the rotating micromirror under appropriate conditions, i.e., at an angle less than the critical angle for reflectivity. The time window for such deflections depends on the frequency and amplitude of the MEMS rotation. We demonstrate that reflection geometry can produce a time window of a few microseconds. We further demonstrate that MEMS optics can isolate x rays from a selected synchrotron bunch or group of bunches. With ray-trace simulations we explain the currently achievable time windows and suggest a path toward improvements.

Alternative approach for management of an electrical storm in Brugada syndrome:Importance of primary ablation within a narrow time window.

PubMed

Talib, Ahmed Karim; Yui, Yoshiaki; Kaneshiro, Takashi; Sekiguchi, Yukio; Nogami, Akihiko; Aonuma, Kazutaka

2016-06-01

Placement of an implantable cardioverter-defibrillator (ICD) is the only powerful treatment modality for Brugada syndrome in patients presenting with ventricular fibrillation (VF). For those whose first presentation is an electrical storm, pharmacologic therapy is typically used to control VF followed by ICD implantation. We report an alternative approach whereby, before ICD implantation, emergency catheter ablation of the VF-triggering premature ventricular contraction (PVC) resulted in long-term VF-free survival. The results suggest that, because VF triggers appear in a narrow time window, ablation of the culprit PVCs that initiate VF before the index PVCs subside is a reasonable alternative approach.

State-of-the-art software for window energy-efficiency rating and labeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arasteh, D.; Finlayson, E.; Huang, J.

1998-07-01

Measuring the thermal performance of windows in typical residential buildings is an expensive proposition. Not only is laboratory testing expensive, but each window manufacturer typically offers hundreds of individual products, each of which has different thermal performance properties. With over a thousand window manufacturers nationally, a testing-based rating system would be prohibitively expensive to the industry and to consumers. Beginning in the early 1990s, simulation software began to be used as part of a national program for rating window U-values. The rating program has since been expanded to include Solar Hear Gain Coefficients and is now being extended to annualmore » energy performance. This paper describes four software packages available to the public from Lawrence Berkeley National Laboratory (LBNL). These software packages are used to evaluate window thermal performance: RESFEN (for evaluating annual energy costs), WINDOW (for calculating a product`s thermal performance properties), THERM (a preprocessor for WINDOW that determines two-dimensional heat-transfer effects), and Optics (a preprocessor for WINDOW`s glass database). Software not only offers a less expensive means than testing to evaluate window performance, it can also be used during the design process to help manufacturers produce windows that will meet target specifications. In addition, software can show small improvements in window performance that might not be detected in actual testing because of large uncertainties in test procedures.« less

A Simulation Study of Paced TCP

NASA Technical Reports Server (NTRS)

Kulik, Joanna; Coulter, Robert; Rockwell, Dennis; Partridge, Craig

2000-01-01

In this paper, we study the performance of paced TCP, a modified version of TCP designed especially for high delay- bandwidth networks. In typical networks, TCP optimizes its send-rate by transmitting increasingly large bursts, or windows, of packets, one burst per round-trip time, until it reaches a maximum window-size, which corresponds to the full capacity of the network. In a network with a high delay-bandwidth product, however, Transmission Control Protocol's (TCPs) maximum window-size may be larger than the queue size of the intermediate routers, and routers will begin to drop packets as soon as the windows become too large for the router queues. The TCP sender then concludes that the bottleneck capacity of the network has been reached, and it limits its send-rate accordingly. Partridge proposed paced TCP as a means of solving the problem of queueing bottlenecks. A sender using paced TCP would release packets in multiple, small bursts during a round-trip time in which ordinary TCP would release a single, large burst of packets. This approach allows the sender to increase its send-rate to the maximum window size without encountering queueing bottlenecks. This paper describes the performance of paced TCP in a simulated network and discusses implementation details that can affect the performance of paced TCP.

Energy use behaviour: A window of opportunity

NASA Astrophysics Data System (ADS)

Roy, Deborah

2017-06-01

The environmental impact of electric vehicles depends on the kind of energy used to charge them. They are typically charged at peak times, when extra fossil fuels are needed to meet energy demands. A study shows that e-mails targeting electric vehicle charging for new owners can be effective for promoting greener charging behaviours.

Overview of Fabrication Techniques and Lessons Learned with Accelerator Vacuum Windows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ader, C. R.; McGee, M. W.; Nobrega, L. E.

Vacuum thin windows have been used in Fermilab's accelerators for decades and typically have been overlooked in terms of their criticality and fragility. Vacuum windows allow beam to pass through while creating a boundary between vacuum and air or high vacuum and low vacuum areas. The design of vacuum windows, including Titanium and Beryllium windows, will be discussed as well as fabrication, testing, and operational concerns. Failure of windows will be reviewed as well as safety approaches to mitigating failures and extending the lifetimes of vacuum windows. Various methods of calculating the strengths of vacuum windows will be explored, includingmore » FEA.« less

Extreme multi-basin fluvial flows and their relationship to extra-tropical cyclones

NASA Astrophysics Data System (ADS)

De Luca, Paolo; Hillier, John K.; Wilby, Robert L.; Quinn, Nevil W.; Harrigan, Shaun

2017-04-01

Fluvial floods are typically investigated as 'events' at the single basin scale, thereby implicitly assuming that severe flooding impacts each catchment independently from those nearby. A statistical analysis of the spatio-temporal characteristics of extreme flows in Great Britain (GB), during 1975-2014, is presented. These observations deepen understanding of the processes leading to multi-basin floods and present helpful insights for contingency planning and emergency responders. The largest multi-basin peak flow events within different time windows were identified by counting the number of coincident annual maximum river peak flows (AMAX) across 261 non-nested catchments, using search windows of 1 to 19 days. This showed that up to 107 basins reached their AMAX within the same plateauing 13-day window, draining a total area equivalent to ˜46% of the overall basins considered, which is an equivalent fraction of ˜27% of Great Britain. Such episodes are typically associated with persistent cyclonic atmospheric circulation and saturated ground, combined with short hydrological response times (<48 h) from large contributing basins. The most spatially extensive episodes also tend to coincide with the most severe gales (i.e. extra-tropical cyclones) on a ±0-13 day time-scale. The analysis suggests that multi-basin peak flow events can be characterised by concurrent peak flow AMAX and that the most extreme are driven by very severe gales (VSG). This has implications for emergency response including planning for combined flood-wind impacts (on for example power and communication systems), meaning that the emergency preparedness need to be reorganised in order to face this peril.

Short time Fourier analysis of the electromyogram - Fast movements and constant contraction

NASA Technical Reports Server (NTRS)

Hannaford, Blake; Lehman, Steven

1986-01-01

Short-time Fourier analysis was applied to surface electromyograms (EMG) recorded during rapid movements, and during isometric contractions at constant forces. A portion of the data to be transformed by multiplying the signal by a Hamming window was selected, and then the discrete Fourier transform was computed. Shifting the window along the data record, a new spectrum was computed each 10 ms. The transformed data were displayed in spectograms or 'voiceprints'. This short-time technique made it possible to see time-dependencies in the EMG that are normally averaged in the Fourier analysis of these signals. Spectra of EMGs during isometric contractions at constant force vary in the short (10-20 ms) term. Short-time spectra from EMGs recorded during rapid movements were much less variable. The windowing technique picked out the typical 'three-burst pattern' in EMG's from both wrist and head movements. Spectra during the bursts were more consistent than those during isometric contractions. Furthermore, there was a consistent shift in spectral statistics in the course of the three bursts. Both the center frequency and the variance of the spectral energy distribution grew from the first burst to the second burst in the same muscle. The analogy between EMGs and speech signals is extended to argue for future applicability of short-time spectral analysis of EMG.

Analysis of oil-pipeline distribution of multiple products subject to delivery time-windows

NASA Astrophysics Data System (ADS)

Jittamai, Phongchai

This dissertation defines the operational problems of, and develops solution methodologies for, a distribution of multiple products into oil pipeline subject to delivery time-windows constraints. A multiple-product oil pipeline is a pipeline system composing of pipes, pumps, valves and storage facilities used to transport different types of liquids. Typically, products delivered by pipelines are petroleum of different grades moving either from production facilities to refineries or from refineries to distributors. Time-windows, which are generally used in logistics and scheduling areas, are incorporated in this study. The distribution of multiple products into oil pipeline subject to delivery time-windows is modeled as multicommodity network flow structure and mathematically formulated. The main focus of this dissertation is the investigation of operating issues and problem complexity of single-source pipeline problems and also providing solution methodology to compute input schedule that yields minimum total time violation from due delivery time-windows. The problem is proved to be NP-complete. The heuristic approach, a reversed-flow algorithm, is developed based on pipeline flow reversibility to compute input schedule for the pipeline problem. This algorithm is implemented in no longer than O(T·E) time. This dissertation also extends the study to examine some operating attributes and problem complexity of multiple-source pipelines. The multiple-source pipeline problem is also NP-complete. A heuristic algorithm modified from the one used in single-source pipeline problems is introduced. This algorithm can also be implemented in no longer than O(T·E) time. Computational results are presented for both methodologies on randomly generated problem sets. The computational experience indicates that reversed-flow algorithms provide good solutions in comparison with the optimal solutions. Only 25% of the problems tested were more than 30% greater than optimal values and approximately 40% of the tested problems were solved optimally by the algorithms.

Rigid thin windows for vacuum applications

DOEpatents

Meyer, Glenn Allyn; Ciarlo, Dino R.; Myers, Booth Richard; Chen, Hao-Lin; Wakalopulos, George

1999-01-01

A thin window that stands off atmospheric pressure is fabricated using photolithographic and wet chemical etching techniques and comprises at least two layers: an etch stop layer and a protective barrier layer. The window structure also comprises a series of support ribs running the width of the window. The windows are typically made of boron-doped silicon and silicon nitride and are useful in instruments such as electron beam guns and x-ray detectors. In an electron beam gun, the window does not impede the electrons and has demonstrated outstanding gun performance and survivability during the gun tube manufacturing process.

Ocean Engineering Studies Compiled 1991. Volume 6. Acrylic Windows - Typical Applications in Pressure Housings

DTIC Science & Technology

1991-01-01

either the metallic or plastic composite pressure envelope. The ASME Boiler and Pressure Vessel Code Section 8 provides such design criteria, and the...fabricated of metallic or piastic composite materials. To preclude potential catastrophic failures of windows designed on the basis of inadequate data, in...pressure-resistant acrylic windows (reference 12). Acrylic windows are usually machined from Plexiglas G plate, which is limited in thickness to 4 inches

Long-term High-Resolution Intravital Microscopy in the Lung with a Vacuum Stabilized Imaging Window

PubMed Central

Rodriguez-Tirado, Carolina; Kitamura, Takanori; Kato, Yu; Pollard, Jeffery W.; Condeelis, John S.; Entenberg, David

2017-01-01

Metastasis to secondary sites such as the lung, liver and bone is a traumatic event with a mortality rate of approximately 90% 1. Of these sites, the lung is the most difficult to assess using intravital optical imaging due to its enclosed position within the body, delicate nature and vital role in sustaining proper physiology. While clinical modalities (positron emission tomography (PET), magnetic resonance imaging (MRI) and computed tomography (CT)) are capable of providing noninvasive images of this tissue, they lack the resolution necessary to visualize the earliest seeding events, with a single pixel consisting of nearly a thousand cells. Current models of metastatic lung seeding postulate that events just after a tumor cell's arrival are deterministic for survival and subsequent growth. This means that real-time intravital imaging tools with single cell resolution 2 are required in order to define the phenotypes of the seeding cells and test these models. While high resolution optical imaging of the lung has been performed using various ex vivo preparations, these experiments are typically single time-point assays and are susceptible to artifacts and possible erroneous conclusions due to the dramatically altered environment (temperature, profusion, cytokines, etc.) resulting from removal from the chest cavity and circulatory system 3. Recent work has shown that time-lapse intravital optical imaging of the intact lung is possible using a vacuum stabilized imaging window 2,4,5 however, typical imaging times have been limited to approximately 6 hr. Here we describe a protocol for performing long-term intravital time-lapse imaging of the lung utilizing such a window over a period of 12 hr. The time-lapse image sequences obtained using this method enable visualization and quantitation of cell-cell interactions, membrane dynamics and vascular perfusion in the lung. We further describe an image processing technique that gives an unprecedentedly clear view of the lung microvasculature. PMID:27768066

A General Audiovisual Temporal Processing Deficit in Adult Readers With Dyslexia.

PubMed

Francisco, Ana A; Jesse, Alexandra; Groen, Margriet A; McQueen, James M

2017-01-01

Because reading is an audiovisual process, reading impairment may reflect an audiovisual processing deficit. The aim of the present study was to test the existence and scope of such a deficit in adult readers with dyslexia. We tested 39 typical readers and 51 adult readers with dyslexia on their sensitivity to the simultaneity of audiovisual speech and nonspeech stimuli, their time window of audiovisual integration for speech (using incongruent /aCa/ syllables), and their audiovisual perception of phonetic categories. Adult readers with dyslexia showed less sensitivity to audiovisual simultaneity than typical readers for both speech and nonspeech events. We found no differences between readers with dyslexia and typical readers in the temporal window of integration for audiovisual speech or in the audiovisual perception of phonetic categories. The results suggest an audiovisual temporal deficit in dyslexia that is not specific to speech-related events. But the differences found for audiovisual temporal sensitivity did not translate into a deficit in audiovisual speech perception. Hence, there seems to be a hiatus between simultaneity judgment and perception, suggesting a multisensory system that uses different mechanisms across tasks. Alternatively, it is possible that the audiovisual deficit in dyslexia is only observable when explicit judgments about audiovisual simultaneity are required.

Measurement of absorption spectrum of deuterium oxide (D{sub 2}O) and its application to signal enhancement in multiphoton microscopy at the 1700-nm window

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yuxin; Wen, Wenhui; Wang, Kai

2016-01-11

1700-nm window has been demonstrated to be a promising excitation window for deep-tissue multiphoton microscopy (MPM). Long working-distance water immersion objective lenses are typically used for deep-tissue imaging. However, absorption due to immersion water at 1700 nm is still high and leads to dramatic decrease in signals. In this paper, we demonstrate measurement of absorption spectrum of deuterium oxide (D{sub 2}O) from 1200 nm to 2600 nm, covering the three low water-absorption windows potentially applicable for deep-tissue imaging (1300 nm, 1700 nm, and 2200 nm). We apply this measured result to signal enhancement in MPM at the 1700-nm window. Compared with water immersion, D{sub 2}O immersionmore » enhances signal levels in second-harmonic generation imaging, 3-photon fluorescence imaging, and third-harmonic generation imaging by 8.1, 24.8, and 24.7 times with 1662-nm excitation, in good agreement with theoretical calculation based on our absorption measurement. This suggests D{sub 2}O a promising immersion medium for deep-tissue imaging.« less

Updated System-Availability and Resource-Allocation Program

NASA Technical Reports Server (NTRS)

Viterna, Larry

2004-01-01

A second version of the Availability, Cost and Resource Allocation (ACARA) computer program has become available. The first version was reported in an earlier tech brief. To recapitulate: ACARA analyzes the availability, mean-time-between-failures of components, life-cycle costs, and scheduling of resources of a complex system of equipment. ACARA uses a statistical Monte Carlo method to simulate the failure and repair of components while complying with user-specified constraints on spare parts and resources. ACARA evaluates the performance of the system on the basis of a mathematical model developed from a block-diagram representation. The previous version utilized the MS-DOS operating system and could not be run by use of the most recent versions of the Windows operating system. The current version incorporates the algorithms of the previous version but is compatible with Windows and utilizes menus and a file-management approach typical of Windows-based software.

Windowed Green function method for the Helmholtz equation in the presence of multiply layered media

NASA Astrophysics Data System (ADS)

Bruno, O. P.; Pérez-Arancibia, C.

2017-06-01

This paper presents a new methodology for the solution of problems of two- and three-dimensional acoustic scattering (and, in particular, two-dimensional electromagnetic scattering) by obstacles and defects in the presence of an arbitrary number of penetrable layers. Relying on the use of certain slow-rise windowing functions, the proposed windowed Green function approach efficiently evaluates oscillatory integrals over unbounded domains, with high accuracy, without recourse to the highly expensive Sommerfeld integrals that have typically been used to account for the effect of underlying planar multilayer structures. The proposed methodology, whose theoretical basis was presented in the recent contribution (Bruno et al. 2016 SIAM J. Appl. Math. 76, 1871-1898. (doi:10.1137/15M1033782)), is fast, accurate, flexible and easy to implement. Our numerical experiments demonstrate that the numerical errors resulting from the proposed approach decrease faster than any negative power of the window size. In a number of examples considered in this paper, the proposed method is up to thousands of times faster, for a given accuracy, than corresponding methods based on the use of Sommerfeld integrals.

Windowed Green function method for the Helmholtz equation in the presence of multiply layered media.

PubMed

Bruno, O P; Pérez-Arancibia, C

2017-06-01

This paper presents a new methodology for the solution of problems of two- and three-dimensional acoustic scattering (and, in particular, two-dimensional electromagnetic scattering) by obstacles and defects in the presence of an arbitrary number of penetrable layers. Relying on the use of certain slow-rise windowing functions, the proposed windowed Green function approach efficiently evaluates oscillatory integrals over unbounded domains, with high accuracy, without recourse to the highly expensive Sommerfeld integrals that have typically been used to account for the effect of underlying planar multilayer structures. The proposed methodology, whose theoretical basis was presented in the recent contribution (Bruno et al. 2016 SIAM J. Appl. Math. 76 , 1871-1898. (doi:10.1137/15M1033782)), is fast, accurate, flexible and easy to implement. Our numerical experiments demonstrate that the numerical errors resulting from the proposed approach decrease faster than any negative power of the window size. In a number of examples considered in this paper, the proposed method is up to thousands of times faster, for a given accuracy, than corresponding methods based on the use of Sommerfeld integrals.

Bondable Fluoropolymer Film as a Water Block/Acoustic Window for Environmentally Isolating Acoustic Devices

DTIC Science & Technology

2005-11-30

titanium 2 I foil which is wrapped around a polyurethane molded acoustic 2 device and local preamplifier for the purpose of water-proofing 3 and...typical sonar signals transmitted through the 14 films 12 and 14. Therefore, the film 12 can be added to 15 traditional acoustic window designs to...4 virtually no effect on typical sonar signals yet eliminates an 5 otherwise costly and relatively thick rubber or polymer skin that 6 can be

Manufacturing and metrology for IR conformal windows and domes

NASA Astrophysics Data System (ADS)

Ferralli, Ian; Blalock, Todd; Brunelle, Matt; Lynch, Timothy; Myer, Brian; Medicus, Kate

2017-05-01

Freeform and conformal optics have the potential to dramatically improve optical systems by enabling systems with fewer optical components, reduced aberrations, and improved aerodynamic performance. These optical components differ from standard components in their surface shape, typically a non-symmetric equation based definition, and material properties. Traditional grinding and polishing tools are unable to handle these freeform shapes. Additionally, standard metrology tools cannot measure these surfaces. Desired substrates are typically hard ceramics, including poly-crystalline alumina or aluminum oxynitride. Notwithstanding the challenges that the hardness provides to manufacturing, these crystalline materials can be highly susceptible to grain decoration creating unacceptable scatter in optical systems. In this presentation, we will show progress towards addressing the unique challenges of manufacturing conformal windows and domes. Particular attention is given to our robotic polishing platform. This platform is based on an industrial robot adapted to accept a wide range of tooling and parts. The robot's flexibility has provided us an opportunity to address the unique challenges of conformal windows. Slurries and polishing active layers can easily be changed to adapt to varying materials and address grain decoration. We have the flexibility to change tool size and shape to address the varying sizes and shapes of conformal optics. In addition, the robotic platform can be a base for a deflectometry-based metrology tool to measure surface form error. This system, whose precision is independent of the robot's positioning accuracy, will allow us to measure optics in-situ saving time and reducing part risk. In conclusion, we will show examples of the conformal windows manufactured using our developed processes.

Experimental and Numerical Examination of the Thermal Transmittance of High Performance Window Frames

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gustavsen Ph.D., Arild; Goudey, Howdy; Kohler, Christian

2010-06-17

While window frames typically represent 20-30percent of the overall window area, their impact on the total window heat transfer rates may be much larger. This effect is even greater in low-conductance (highly insulating) windows which incorporate very low conductance glazings. Developing low-conductance window frames requires accurate simulation tools for product research and development. The Passivhaus Institute in Germany states that windows (glazing and frames, combined) should have U-values not exceeding 0.80 W/(m??K). This has created a niche market for highly insulating frames, with frame U-values typically around 0.7-1.0 W/(m2 cdot K). The U-values reported are often based on numerical simulationsmore » according to international simulation standards. It is prudent to check the accuracy of these calculation standards, especially for high performance products before more manufacturers begin to use them to improve other product offerings. In this paper the thermal transmittance of five highly insulating window frames (three wooden frames, one aluminum frame and one PVC frame), found from numerical simulations and experiments, are compared. Hot box calorimeter results are compared with numerical simulations according to ISO 10077-2 and ISO 15099. In addition CFD simulations have been carried out, in order to use the most accurate tool available to investigate the convection and radiation effects inside the frame cavities. Our results show that available tools commonly used to evaluate window performance, based on ISO standards, give good overall agreement, but specific areas need improvement.« less

Evaluation of solar gain through skylights for inclusion in the SP53 residential building loads data base

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hanford, J.W.; Huang, Y.J.

The energy performance of skylights is similar to that of windows in admitting solar heat gain, while at the same time providing a pathway for convective and conductive heat transfer through the building envelope. Since skylights are typically installed at angles ranging from 0{degrees} to 45{degrees}, and differ from windows in both their construction and operation, their conductive and convective heat gains or losses, as well as solar heat gain, will differ for the same rough opening and thermal characteristics. The objective of this work is to quantify the impact of solar gain through skylights on building heating and coolingmore » loads in 45 climates, and to develop a method for including these data into the SP53 residential loads data base previously developed by LBL in support of DOE`s Automated Residential Energy Standard (ARES) program. The authors used the DOE-2.1C program to simulate the heating and cooling loads of a prototypical residential building while varying the size and solar characteristics of skylights and windows. The results are presented as Skylight Solar Loads, which are the contribution of solar gains through skylights to the overall building heating and cooling loads, and as Skylight Solar Load Ratios, which are the ratios of skylight solar loads to those for windows with the same orientation. The study shows that skylight solar loads are larger than those for windows in both heating and cooling. Skylight solar cooling loads are from three to four times greater than those for windows regardless of the skylight tilt, except for those facing north. These cooling loads are largest for south-facing skylights at a tilt angle of approximately 20{degrees}, and drop off at higher tilts and other orientations.« less

Back-Projection Imaging of extended, diffuse seismic sources in volcanic and hydrothermal systems

NASA Astrophysics Data System (ADS)

Kelly, C. L.; Lawrence, J. F.; Beroza, G. C.

2017-12-01

Volcanic and hydrothermal systems exhibit a wide range of seismicity that is directly linked to fluid and volatile activity in the subsurface and that can be indicative of imminent hazardous activity. Seismograms recorded near volcanic and hydrothermal systems typically contain "noisy" records, but in fact, these complex signals are generated by many overlapping low-magnitude displacements and pressure changes at depth. Unfortunately, excluding times of high-magnitude eruptive activity that typically occur infrequently relative to the length of a system's entire eruption cycle, these signals often have very low signal-to-noise ratios and are difficult to identify and study using established seismic analysis techniques (i.e. phase-picking, template matching). Arrays of short-period and broadband seismic sensors are proven tools for monitoring short- and long-term changes in volcanic and hydrothermal systems. Time-reversal techniques (i.e. back-projection) that are improved by additional seismic observations have been successfully applied to locating volcano-seismic sources recorded by dense sensor arrays. We present results from a new computationally efficient back-projection method that allows us to image the evolution of extended, diffuse sources of volcanic and hydrothermal seismicity. We correlate short time-window seismograms from receiver-pairs to find coherent signals and propagate them back in time to potential source locations in a 3D subsurface model. The strength of coherent seismic signal associated with any potential source-receiver-receiver geometry is equal to the correlation of the short time-windows of seismic records at appropriate time lags as determined by the velocity structure and ray paths. We stack (sum) all short time-window correlations from all receiver-pairs to determine the cumulative coherence of signals at each potential source location. Through stacking, coherent signals from extended and/or repeating sources of short-period energy radiation interfere constructively while background noise signals interfere destructively, such that the most likely source locations of the observed seismicity are illuminated. We compile results to analyze changes in the distribution and prevalence of these sources throughout a systems entire eruptive cycle.

Probability of a false-negative HIV antibody test result during the window period: a tool for pre- and post-test counselling.

PubMed

Taylor, Darlene; Durigon, Monica; Davis, Heather; Archibald, Chris; Konrad, Bernhard; Coombs, Daniel; Gilbert, Mark; Cook, Darrel; Krajden, Mel; Wong, Tom; Ogilvie, Gina

2015-03-01

Failure to understand the risk of false-negative HIV test results during the window period results in anxiety. Patients typically want accurate test results as soon as possible while clinicians prefer to wait until the probability of a false-negative is virtually nil. This review summarizes the median window periods for third-generation antibody and fourth-generation HIV tests and provides the probability of a false-negative result for various days post-exposure. Data were extracted from published seroconversion panels. A 10-day eclipse period was used to estimate days from infection to first detection of HIV RNA. Median (interquartile range) days to seroconversion were calculated and probabilities of a false-negative result at various time periods post-exposure are reported. The median (interquartile range) window period for third-generation tests was 22 days (19-25) and 18 days (16-24) for fourth-generation tests. The probability of a false-negative result is 0.01 at 80 days' post-exposure for third-generation tests and at 42 days for fourth-generation tests. The table of probabilities of falsely-negative HIV test results may be useful during pre- and post-test HIV counselling to inform co-decision making regarding the ideal time to test for HIV. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Automated Measurement of P- and S-Wave Differential Times for Imaging Spatial Distributions of Vp/Vs Ratio, with Moving-Window Cross-Correlation Technique

NASA Astrophysics Data System (ADS)

Taira, T.; Kato, A.

2013-12-01

A high-resolution Vp/Vs ratio estimate is one of the key parameters to understand spatial variations of composition and physical state within the Earth. Lin and Shearer (2007, BSSA) recently developed a methodology to obtain local Vp/Vs ratios in individual similar earthquake clusters, based on P- and S-wave differential times. A waveform cross-correlation approach is typically employed to measure those differential times for pairs of seismograms from similar earthquakes clusters, at narrow time windows around the direct P and S waves. This approach effectively collects P- and S-wave differential times and however requires the robust P- and S-wave time windows that are extracted based on either manually or automatically picked P- and S-phases. We present another technique to estimate P- and S-wave differential times by exploiting temporal properties of delayed time as a function of elapsed time on the seismograms with a moving-window cross-correlation analysis (e.g., Snieder, 2002, Phys. Rev. E; Niu et al. 2003, Nature). Our approach is based on the principle that the delayed time for the direct S wave differs from that for the direct P wave. Two seismograms aligned by the direct P waves from a pair of similar earthquakes yield that delayed times become zero around the direct P wave. In contrast, delayed times obtained from time windows including the direct S wave have non-zero value. Our approach, in principle, is capable of measuring both P- and S-wave differential times from single-component seismograms. In an ideal case, the temporal evolution of delayed time becomes a step function with its discontinuity at the onset of the direct S wave. The offset in the resulting step function would be the S-wave differential time, relative to the P-wave differential time as the two waveforms are aligned by the direct P wave. We apply our moving-window cross-correlation technique to the two different data sets collected at: 1) the Wakayama district, Japan and 2) the Geysers geothermal field, California. The both target areas are characterized by earthquake swarms that provide a number of similar events clusters. We use the following automated procedure to systematically analyze the two data sets: 1) the identification of the direct P arrivals by using an Akaike Information Criterion based phase picking algorithm introduced by Zhang and Thurber (2003, BSSA), 2) the waveform alignment by the P-wave with a waveform cross-correlation to obtain P-wave differential time, 3) the moving-time window analysis to estimate the S-differential time. Kato et al. (2010, GRL) have estimated the Vp/Vs ratios for a few similar earthquake clusters from the Wakayama data set, by a conventional approach to obtain differential times. We find that the resulting Vp/Vs ratios from our approach for the same earthquake clusters are comparable with those obtained from Kato et al. (2010, GRL). We show that the moving-window cross-correlation technique effectively measures both P- and S-wave differential times for the seismograms in which the clear P and S phases are not observed. We will show spatial distributions in Vp/Vs ratios in our two target areas.

Water vapour foreign-continuum absorption in near-infrared windows from laboratory measurements.

PubMed

Ptashnik, Igor V; McPheat, Robert A; Shine, Keith P; Smith, Kevin M; Williams, R Gary

2012-06-13

For a long time, it has been believed that atmospheric absorption of radiation within wavelength regions of relatively high infrared transmittance (so-called 'windows') was dominated by the water vapour self-continuum, that is, spectrally smooth absorption caused by H(2)O--H(2)O pair interaction. Absorption due to the foreign continuum (i.e. caused mostly by H(2)O--N(2) bimolecular absorption in the Earth's atmosphere) was considered to be negligible in the windows. We report new retrievals of the water vapour foreign continuum from high-resolution laboratory measurements at temperatures between 350 and 430 K in four near-infrared windows between 1.1 and 5 μm (9000-2000 cm(-1)). Our results indicate that the foreign continuum in these windows has a very weak temperature dependence and is typically between one and two orders of magnitude stronger than that given in representations of the continuum currently used in many climate and weather prediction models. This indicates that absorption owing to the foreign continuum may be comparable to the self-continuum under atmospheric conditions in the investigated windows. The calculated global-average clear-sky atmospheric absorption of solar radiation is increased by approximately 0.46 W m(-2) (or 0.6% of the total clear-sky absorption) by using these new measurements when compared with calculations applying the widely used MTCKD (Mlawer-Tobin-Clough-Kneizys-Davies) foreign-continuum model.

Predictability effect on N400 reflects the severity of reading comprehension deficits in aphasia.

PubMed

Chang, Chih-Ting; Lee, Chia-Ying; Chou, Chia-Ju; Fuh, Jong-Ling; Wu, Hsin-Chi

2016-01-29

Predictability effect on N400, in which low predictability words elicited a larger N400 than high predictability words did over central to posterior electrodes, has been used to index difficulty of lexical retrieval and semantic integration of words in sentence comprehension. This study examined predictability effect on N400 in aphasic patients to determine if the properties of N400 are suited to indexing the severity of reading comprehension deficits. Patients with aphasia were divided into high and low ability groups based on scores on the reading comprehension subtest in the Chinese Concise Aphasia Test (CCAT). The two aphasia groups, a group of healthy elders who were age-matched to the aphasic participants, and a group of young adults, were requested to read sentences that either ended with highly predictable words or unexpected but plausible words, while undergoing electroencephalography (EEG). The young adult and healthy elderly groups exhibited the typical centro-parietal distributed effect of predictability on N400; however, healthy elders exhibited a reduced N400 effect in a delayed time window compared to the young adults. Compared with the elderly control, the high ability aphasia group exhibited a comparable N400 effect in a more restricted time window; by contrast, the low ability aphasia group exhibited a frontal distributed N400 in a much later time window (400-700 ms). These data suggest that the severity of reading comprehension deficits affects predictability effect on a set of N400 characteristics (i.e., amplitude, time window, and topographic distribution), which may be effective as ERP signatures in the evaluation of language recovery in aphasia. Copyright © 2015 Elsevier Ltd. All rights reserved.

Determination of design and operation parameters for upper atmospheric research instrumentation to yield optimum resolution with deconvolution, appendix 4

NASA Technical Reports Server (NTRS)

Ioup, George E.; Ioup, Juliette W.

1989-01-01

The power spectrum for a stationary random process can be defined with the Wiener-Khintchine Theorem, which says that the power spectrum and the auto correlation function are a Fourier transform pair. To implement this theorem for signals that are discrete and of finite length we can use the Blackman-Tukey method. Blackman and Tukey (1958) show that a function w(tau), called a lag window, can be applied to the auto correlation estimates to obtain power spectrum estimates that are statistically stable. The Fourier transform of w(r) is called a spectral window. Typical choices for spectral windows show a distinct trade-off between the main lobe width and side lobe strength. A new idea for designing windows by taking linear combinations of the standard windows to produce hybrid windows was introduced by Smith (1985). We implement Smith's idea to obtain spectral windows with narrow main lobes and smaller (compared with typical windows) near side lobes. One of the main contributions of this thesis is that we show that Smith's problem is equivalent to a Quadratic Programming (QP) problem with linear equality and inequality constraints. A computer program was written to produce hybrid windows by setting up and solving the QP problem. We also developed and solved two variations of the original problem. The two variations involved changing the inequality constraints in both cases from non negativity on the combination coefficients to non negativity on the hybrid lag window itself. For the second variation, the window functions used to construct the hybrid window were changed to a frequency-variable set of truncated cosinusoids. A series of tests was run with the three computer programs to investigate the behavior of the hybrid spectral and lag windows. Emphasis was put on obtaining spectral windows with both relatively narrow main lobes and the lowest possible (for these algorithms) near side lobes. Some success was achieved for this goal. A 10 dB peak side lobe reduction over the rectangular spectral window without significant main lobe broadening was achieved. Also, average side lobe levels of -117 dB were reached at a cost of doubling the main lobe width (at the -3 dB point).

A data driven method for estimation of B(avail) and appK(D) using a single injection protocol with [¹¹C]raclopride in the mouse.

PubMed

Wimberley, Catriona J; Fischer, Kristina; Reilhac, Anthonin; Pichler, Bernd J; Gregoire, Marie Claude

2014-10-01

The partial saturation approach (PSA) is a simple, single injection experimental protocol that will estimate both B(avail) and appK(D) without the use of blood sampling. This makes it ideal for use in longitudinal studies of neurodegenerative diseases in the rodent. The aim of this study was to increase the range and applicability of the PSA by developing a data driven strategy for determining reliable regional estimates of receptor density (B(avail)) and in vivo affinity (1/appK(D)), and validate the strategy using a simulation model. The data driven method uses a time window guided by the dynamic equilibrium state of the system as opposed to using a static time window. To test the method, simulations of partial saturation experiments were generated and validated against experimental data. The experimental conditions simulated included a range of receptor occupancy levels and three different B(avail) and appK(D) values to mimic diseases states. Also the effect of using a reference region and typical PET noise on the stability and accuracy of the estimates was investigated. The investigations showed that the parameter estimates in a simulated healthy mouse, using the data driven method were within 10±30% of the simulated input for the range of occupancy levels simulated. Throughout all experimental conditions simulated, the accuracy and robustness of the estimates using the data driven method were much improved upon the typical method of using a static time window, especially at low receptor occupancy levels. Introducing a reference region caused a bias of approximately 10% over the range of occupancy levels. Based on extensive simulated experimental conditions, it was shown the data driven method provides accurate and precise estimates of B(avail) and appK(D) for a broader range of conditions compared to the original method. Copyright © 2014 Elsevier Inc. All rights reserved.

A case study of exposure to ultrafine particles from secondhand tobacco smoke in an automobile.

PubMed

Liu, S; Zhu, Y

2010-10-01

Secondhand tobacco smoke (SHS) in enclosed spaces is a major source of potentially harmful airborne particles. To quantify exposure to ultrafine particles (UFP) because of SHS and to investigate the interaction between pollutants from SHS and vehicular emissions, number concentration and size distribution of UFP and other air pollutants (CO, CO(2) , and PM(2.5)) were measured inside a moving vehicle under five different ventilation conditions. A major interstate freeway with a speed limit of 60 mph and an urban roadway with a speed limit of 30 mph were selected to represent typical urban routes. In a typical 30-min commute on urban roadways, the SHS of one cigarette exposed passengers to approximately 10 times the UFP and 120 times the PM(2.5) of ambient air. The most effective solution to protect passengers from SHS exposure is to abstain from smoking in the vehicle. Opening a window is an effective method for decreasing pollutant exposures on most urban roadways. However, under road conditions with high UFP concentrations, such as tunnels or busy freeways with high proportion of heavy-duty diesel trucks (such as the 710 Freeway in Los Angeles, CA, USA), opening a window is not a viable method to reduce UFPs. Time budget studies show that Americans spend, on average, more than 60 min each day in enclosed vehicles. Smoking inside vehicles can expose the driver and other passengers to high levels of pollutants. Thus, an understanding of the variations and interactions of secondhand tobacco smoke (SHS) and vehicular emissions under realistic driving conditions is necessary. Results of this study indicated that high ventilation rates can effectively dilute ultrafine particles (UFP) inside moving vehicles on urban routes. However, driving with open windows and an increased air exchange rate (AER) are not recommended on tunnels and heavily travelled freeways.

Reduced cost and improved figure of sapphire optical components

NASA Astrophysics Data System (ADS)

Walters, Mark; Bartlett, Kevin; Brophy, Matthew R.; DeGroote Nelson, Jessica; Medicus, Kate

2015-10-01

Sapphire presents many challenges to optical manufacturers due to its high hardness and anisotropic properties. Long lead times and high prices are the typical result of such challenges. The cost of even a simple 'grind and shine' process can be prohibitive. The high precision surfaces required by optical sensor applications further exacerbate the challenge of processing sapphire thereby increasing cost further. Optimax has demonstrated a production process for such windows that delivers over 50% time reduction as compared to traditional manufacturing processes for sapphire, while producing windows with less than 1/5 wave rms figure error. Optimax's sapphire production process achieves significant improvement in cost by implementation of a controlled grinding process to present the best possible surface to the polishing equipment. Following the grinding process is a polishing process taking advantage of chemical interactions between slurry and substrate to deliver excellent removal rates and surface finish. Through experiments, the mechanics of the polishing process were also optimized to produce excellent optical figure. In addition to reducing the cost of producing large sapphire sensor windows, the grinding and polishing technology Optimax has developed aids in producing spherical sapphire components to better figure quality. In addition to reducing the cost of producing large sapphire sensor windows, the grinding and polishing technology Optimax has developed aids in producing spherical sapphire components to better figure quality. Through specially developed polishing slurries, the peak-to-valley figure error of spherical sapphire parts is reduced by over 80%.

Investigation on Improvements in Lightning Retest Criteria for Spacecraft

NASA Technical Reports Server (NTRS)

Terseck, Alex; Trout, Dawn

2016-01-01

Spacecraft are generally protected from a direct strike by launch the vehicle and ground structures, but protocols to evaluate the impact of nearby strikes are not consistent. Often spacecraft rely on the launch vehicle constraints to trigger a retest, but launch vehicles can typically evaluate the impact of a strike within minutes while spacecraft evaluation times can be on the order of hours or even days. For launches at the Kennedy Space Center where lightning activity is among the highest in the United States, this evaluation related delay could be costly with the possibility of missing the launch window altogether. This paper evaluated available data from local lightning measurements systems and computer simulations to predict the coupled effect from various nearby strikes onto a typical payload umbilical. Recommendations are provided to reduce the typical trigger criteria and costly delays.

Effects of a Longer Detection Window in VHF Time-of-Arrival Lightning Detection Systems

NASA Astrophysics Data System (ADS)

Murphy, M.; Holle, R.; Demetriades, N.

2003-12-01

Lightning detection systems that operate by measuring the times of arrival (TOA) of short bursts of radiation at VHF can produce huge volumes of data. The first automated system of this kind, the NASA Kennedy Space Center LDAR network, is capable of producing one detection every 100 usec from each of seven sensors (Lennon and Maier, 1991), where each detection consists of the time and amplitude of the highest-amplitude peak observed within the 100 usec window. More modern systems have been shown to produce very detailed information with one detection every 10 usec (Rison et al., 2001). Operating such systems in real time, however, can become expensive because of the large data communications rates required. One solution to this problem is to use a longer detection window, say 500 usec. In principle, this has little or no effect on the flash detection efficiency because each flash typically produces a very large number of these VHF bursts (known as sources). By simply taking the largest-amplitude peak from every 500-usec interval instead of every 100-usec interval, we should detect the largest 20{%} of the sources that would have been detected using the 100-usec window. However, questions remain about the exact effect of a longer detection window on the source detection efficiency with distance from the network, its effects on how well flashes are represented in space, and how well the reduced information represents the parent thunderstorm. The latter issue is relevant for automated location and tracking of thunderstorm cells using data from VHF TOA lightning detection networks, as well as for understanding relationships between lightning and severe weather. References Lennon, C.L. and L.M. Maier, Lightning mapping system. Proceedings, Intl. Aerospace and Ground Conf. on Lightning and Static Elec., Cocoa Beach, Fla., NASA Conf. Pub. 3106, vol. II, pp. 89-1 - 89-10, 1991. Rison, W., P. Krehbiel, R. Thomas, T. Hamlin, J. Harlin, High time resolution lightning mapping observations of a small thunderstorm during STEPS. Eos Trans. AGU, 82 (47), Fall Meet. Suppl., Abstract AE12A-83, 2001.

Continuous Particulate Filter State of Health Monitoring Using Radio Frequency Sensing

DOE PAGES

Sappok, Alexander; Ragaller, Paul; Herman, Andrew; ...

2018-04-03

Reliable means for on-board detection of particulate filter failures or malfunctions are needed to meet diagnostics (OBD) requirements. Detecting these failures, which result in tailpipe particulate matter (PM) emissions exceeding the OBD limit, over all operating conditions is challenging. Current approaches employ differential pressure sensors and downstream PM sensors, in combination with particulate filter and engine-out soot models. These conventional monitors typically operate over narrowly-defined time windows and do not provide a direct measure of the filter’s state of health. In contrast, radio frequency (RF) sensors, which transmit a wireless signal through the filter substrate provide a direct means formore » interrogating the condition of the filter itself. Here, this study investigated the use of RF sensors for the continuous measurement of filter trapping efficiency, which was compared to downstream measurements with an AVL Microsoot Sensor, and a PM sampling probe simulating the geometry and installation configuration of a conventional PM sensor. The study included several particulate filter failure modes, both above and below the OBD threshold. Finally, the results confirmed the use of RF sensors to provide a direct and continuous measure of the particulate filter’s state of health over a range of typical in-use operating conditions, thereby significantly increasing the time window over which filter failures may be detected.« less

Continuous Particulate Filter State of Health Monitoring Using Radio Frequency Sensing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sappok, Alexander; Ragaller, Paul; Herman, Andrew

Reliable means for on-board detection of particulate filter failures or malfunctions are needed to meet diagnostics (OBD) requirements. Detecting these failures, which result in tailpipe particulate matter (PM) emissions exceeding the OBD limit, over all operating conditions is challenging. Current approaches employ differential pressure sensors and downstream PM sensors, in combination with particulate filter and engine-out soot models. These conventional monitors typically operate over narrowly-defined time windows and do not provide a direct measure of the filter’s state of health. In contrast, radio frequency (RF) sensors, which transmit a wireless signal through the filter substrate provide a direct means formore » interrogating the condition of the filter itself. Here, this study investigated the use of RF sensors for the continuous measurement of filter trapping efficiency, which was compared to downstream measurements with an AVL Microsoot Sensor, and a PM sampling probe simulating the geometry and installation configuration of a conventional PM sensor. The study included several particulate filter failure modes, both above and below the OBD threshold. Finally, the results confirmed the use of RF sensors to provide a direct and continuous measure of the particulate filter’s state of health over a range of typical in-use operating conditions, thereby significantly increasing the time window over which filter failures may be detected.« less

Brittle deformation along the Gulf of Alaska margin in response to Paleocene-Eocene triple junction migration: in Sisson

USGS Publications Warehouse

Haeussler, Peter J.; Bradley, Dwight C.; Goldfarb, Richard J.

2003-01-01

A spreading center was subducted diachronously along a 2200 km segment of what is now the Gulf of Alaska margin between 61 and 50 Ma, and left in its wake near-trench intrusions and high-T, low-P metamorphic rocks. Gold-quartz veins and dikes, linked to ridge subduction by geochronological and relative timing evidence, provide a record of brittle deformation during and after passage of the ridge. The gold-quartz veins are typically hosted by faults, and their regional extent indicates there was widespread deformation of the forearc above the slab window at the time of ridge subduction. Considerable variability in the strain pattern was associated with the slab window and the trailing plate. A diffuse network of dextral, sinistral, and normal faults hosted small lode-gold deposits (<50,000 oz) in south-central Alaska, whereas crustal-scale dextral faults in southeastern Alaska are spatially associated with large gold deposits (up to 800,000 oz).We interpret the gold-quartz veins as having formed above an eastward-migrating slab window, where the forearc crust responded to the diminishing influence of the forward subducting plate, the increasing influence of the trailing plate, and the thermal pulse and decreased basal friction from the slab window. In addition, extensional deformation of the forearc resulted from the diverging motions of the two oceanic plates at the margins of the slab window. Factors that complicate interpretations of fault kinematics and near-trench dike orientations include a change in plate motions at ca. 52 Ma, northward translation of the accretionary complex, oroclinal bending of the south-central Alaska margin, and subduction of transform segments. We find the pattern of syn-ridge subduction faulting in southern Alaska is remarkably similar to brittle faults near the Chile triple junction and to earthquake focal mechanisms in the Woodlark basin - the two modern sites of ridge subduction. Therefore, extensional and strike-slip deformation above slab windows may be a common occurrence.

Lensing of Fast Radio Bursts as a Probe of Compact Dark Matter

NASA Astrophysics Data System (ADS)

Muñoz, Julian B.; Kovetz, Ely D.; Dai, Liang; Kamionkowski, Marc

2016-08-01

The possibility that part of the dark matter is made of massive compact halo objects (MACHOs) remains poorly constrained over a wide range of masses, and especially in the 20 - 100 M⊙ window. We show that strong gravitational lensing of extragalactic fast radio bursts (FRBs) by MACHOs of masses larger than ˜20 M⊙ would result in repeated FRBs with an observable time delay. Strong lensing of a FRB by a lens of mass ML induces two images, separated by a typical time delay ˜few×(ML/30 M⊙) msec . Considering the expected FRB detection rate by upcoming experiments, such as canadian hydrogen intensity mapping experiment (CHIME), of 1 04 FRBs per year, we should observe from tens to hundreds of repeated bursts yearly, if MACHOs in this window make up all the dark matter. A null search for echoes with just 1 04 FRBs would constrain the fraction fDM of dark matter in MACHOs to fDM≲0.08 for ML≳20 M⊙ .

Theoretical vibro-acoustic modeling of acoustic noise transmission through aircraft windows

NASA Astrophysics Data System (ADS)

Aloufi, Badr; Behdinan, Kamran; Zu, Jean

2016-06-01

In this paper, a fully vibro-acoustic model for sound transmission across a multi-pane aircraft window is developed. The proposed model is efficiently applied for a set of window models to perform extensive theoretical parametric studies. The studied window configurations generally simulate the passenger window designs of modern aircraft classes which have an exterior multi-Plexiglas pane, an interior single acrylic glass pane and a dimmable glass ("smart" glass), all separated by thin air cavities. The sound transmission loss (STL) characteristics of three different models, triple-, quadruple- and quintuple-paned windows identical in size and surface density, are analyzed for improving the acoustic insulation performances. Typical results describing the influence of several system parameters, such as the thicknesses, number and spacing of the window panes, on the transmission loss are then investigated. In addition, a comparison study is carried out to evaluate the acoustic reduction capability of each window model. The STL results show that the higher frequencies sound transmission loss performance can be improved by increasing the number of window panels, however, the low frequency performance is decreased, particularly at the mass-spring resonances.

How to determine life expectancy change of air pollution mortality: a time series study

PubMed Central

2011-01-01

Background Information on life expectancy (LE) change is of great concern for policy makers, as evidenced by discussions of the "harvesting" (or "mortality displacement") issue, i.e. how large an LE loss corresponds to the mortality results of time series (TS) studies. Whereas loss of LE attributable to chronic air pollution exposure can be determined from cohort studies, using life table methods, conventional TS studies have identified only deaths due to acute exposure, during the immediate past (typically the preceding one to five days), and they provide no information about the LE loss per death. Methods We show how to obtain information on population-average LE loss by extending the observation window (largest "lag") of TS to include a sufficient number of "impact coefficients" for past exposures ("lags"). We test several methods for determining these coefficients. Once all of the coefficients have been determined, the LE change is calculated as time integral of the relative risk change after a permanent step change in exposure. Results The method is illustrated with results for daily data of non-accidental mortality from Hong Kong for 1985 - 2005, regressed against PM10 and SO2 with observation windows up to 5 years. The majority of the coefficients is statistically significant. The magnitude of the SO2 coefficients is comparable to those for PM10. But a window of 5 years is not sufficient and the results for LE change are only a lower bound; it is consistent with what is implied by other studies of long term impacts. Conclusions A TS analysis can determine the LE loss, but if the observation window is shorter than the relevant exposures one obtains only a lower bound. PMID:21450107

The Keck Task Library (KTL)

NASA Technical Reports Server (NTRS)

Lupton, W. F.; Conrad, A. R.

1992-01-01

KTL is a set of routines which eases the job of writing applications which must interact with a variety of underlying sub-systems (known as services). A typical application is an X Window user interface coordinating telescope and instruments. In order to connect to a service, application code specifies a service name--typically an instrument name--and a style, which defines the way in which the application will interact with the service. Two styles are currently supported: keyword, where the application reads and writes named keywords and the resulting inter-task message traffic is hidden; and message, where the application deals directly with messages. The keyword style is intended mainly for user interfaces, and the message style is intended mainly for lower-level applications. KTL applications are event driven: a typical application first connects to all its desired services, then expresses interest in specified events. The application then enters an event dispatch loop in which it waits for events and calls the appropriate service's event-handling routine. Each event is associated with a call-back routine which is invoked when the event occurs. Call-back routines may (and typically do) interact with other sub-systems and KTL provides the means of doing so without blocking the application (vital for X Window user interfaces). This approach is a marriage of ideas culled from the X window, ADAM, Keck instrument, and Keck telescope control systems. A novel feature of KTL is that it knows nothing about any services or styles. Instead it defines a generic set of routines which must be implemented by all services and styles (essentially open(), ioctl(), read(), write(), event(), and close()) and activates sharable libraries at run-time. Services have been implemented (in both keyword and message styles) for HIRES (the Keck high resolution echelle spectrograph built by Lick Observatory), LWS (the Keck long wavelength spectrometer built by UC San Diego), and the Keck telescope. Each of these implementations uses different underlying message systems: the Lick MUSIC system, RPC's, and direct sockets (respectively). Services for the remaining three front-line Keck instruments will be implemented over the next few months.

In vivo THz imaging of human skin: Accounting for occlusion effects.

PubMed

Sun, Qiushuo; Parrott, Edward P J; He, Yuezhi; Pickwell-MacPherson, Emma

2018-02-01

In vivo terahertz (THz) imaging of human skin needs to be done in reflection geometry due to the high attenuation of THz light by water in the skin. To aid the measurement procedure, there is typically an imaging window onto which the patient places the area of interest. The window enables better pulse alignment and helps keep the patient correctly positioned during the measurement. In this paper, we demonstrate how the occlusion caused by the skin contact with the imaging window during the measurement affects the THz response. By studying both rapid point measurements and imaging over an area of a human volar forearm, we find that even 5 seconds of occlusion affects the THz response. As the occlusion time increases, the skin surface water content increases, resulting in the reduction of the amplitude of the reflected THz pulse, especially in the first 3 minutes. Furthermore, it was found that the refractive index of the volar forearm increased by 10% to 15% after 20 minutes of occlusion. In this work, we examine and propose a model for the occlusion effects due to the quartz window with a view to compensating for its influence. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Connectivity dynamics in typical development and its relationship to autistic traits and autism spectrum disorder.

PubMed

Rashid, Barnaly; Blanken, Laura M E; Muetzel, Ryan L; Miller, Robyn; Damaraju, Eswar; Arbabshirani, Mohammad R; Erhardt, Erik B; Verhulst, Frank C; van der Lugt, Aad; Jaddoe, Vincent W V; Tiemeier, Henning; White, Tonya; Calhoun, Vince

2018-03-30

Recent advances in neuroimaging techniques have provided significant insights into developmental trajectories of human brain function. Characterizations of typical neurodevelopment provide a framework for understanding altered neurodevelopment, including differences in brain function related to developmental disorders and psychopathology. Historically, most functional connectivity studies of typical and atypical development operate under the assumption that connectivity remains static over time. We hypothesized that relaxing stationarity assumptions would reveal novel features of both typical brain development related to children on the autism spectrum. We employed a "chronnectomic" (recurring, time-varying patterns of connectivity) approach to evaluate transient states of connectivity using resting-state functional MRI in a population-based sample of 774 6- to 10-year-old children. Dynamic connectivity was evaluated using a sliding-window approach, and revealed four transient states. Internetwork connectivity increased with age in modularized dynamic states, illustrating an important pattern of connectivity in the developing brain. Furthermore, we demonstrated that higher levels of autistic traits and ASD diagnosis were associated with longer dwell times in a globally disconnected state. These results provide a roadmap to the chronnectomic organization of the developing brain and suggest that characteristics of functional brain connectivity are related to children on the autism spectrum. © 2018 Wiley Periodicals, Inc.

Application of Thinned-Skull Cranial Window to Mouse Cerebral Blood Flow Imaging Using Optical Microangiography

PubMed Central

Wang, Ruikang K.

2014-01-01

In vivo imaging of mouse brain vasculature typically requires applying skull window opening techniques: open-skull cranial window or thinned-skull cranial window. We report non-invasive 3D in vivo cerebral blood flow imaging of C57/BL mouse by the use of ultra-high sensitive optical microangiography (UHS-OMAG) and Doppler optical microangiography (DOMAG) techniques to evaluate two cranial window types based on their procedures and ability to visualize surface pial vessel dynamics. Application of the thinned-skull technique is found to be effective in achieving high quality images for pial vessels for short-term imaging, and has advantages over the open-skull technique in available imaging area, surgical efficiency, and cerebral environment preservation. In summary, thinned-skull cranial window serves as a promising tool in studying hemodynamics in pial microvasculature using OMAG or other OCT blood flow imaging modalities. PMID:25426632

The effect of blood acceleration on the ultrasound power Doppler spectrum

NASA Astrophysics Data System (ADS)

Matchenko, O. S.; Barannik, E. A.

2017-09-01

The purpose of the present work was to study the influence of blood acceleration and time window length on the power Doppler spectrum for Gaussian ultrasound beams. The work has been carried out on the basis of continuum model of the ultrasound scattering from inhomogeneities in fluid flow. Correlation function of fluctuations has been considered for uniformly accelerated scatterers, and the resulting power Doppler spectra have been calculated. It is shown that within the initial phase of systole uniformly accelerated slow blood flow in pulmonary artery and aorta tends to make the correlation function about 4.89 and 7.83 times wider, respectively, than the sensitivity function of typical probing system. Given peak flow velocities, the sensitivity function becomes, vice versa, about 4.34 and 3.84 times wider, respectively, then the correlation function. In these limiting cases, the resulting spectra can be considered as Gaussian. The optimal time window duration decreases with increasing acceleration of blood flow and equals to 11.62 and 7.54 ms for pulmonary artery and aorta, respectively. The width of the resulting power Doppler spectrum is shown to be defined mostly by the wave vector of the incident field, the duration of signal and the acceleration of scatterers in the case of low flow velocities. In the opposite case geometrical properties of probing field and the average velocity itself are more essential. In the sense of signal-noise ratio, the optimal duration of time window can be found. Abovementioned results may contribute to the improved techniques of Doppler ultrasound diagnostics of cardiovascular system.

Faithful reconstruction of digital holograms captured by FINCH using a Hamming window function in the Fresnel propagation.

PubMed

Siegel, Nisan; Rosen, Joseph; Brooker, Gary

2013-10-01

Recent advances in Fresnel incoherent correlation holography (FINCH) increase the signal-to-noise ratio in hologram recording by interference of images from two diffractive lenses with focal lengths close to the image plane. Holograms requiring short reconstruction distances are created that reconstruct poorly with existing Fresnel propagation methods. Here we show a dramatic improvement in reconstructed fluorescent images when a 2D Hamming window function substituted for the disk window typically used to bound the impulse response in the Fresnel propagation. Greatly improved image contrast and quality are shown for simulated and experimentally determined FINCH holograms using a 2D Hamming window without significant loss in lateral or axial resolution.

The ACE multi-user web-based Robotic Observatory Control System

NASA Astrophysics Data System (ADS)

Mack, P.

2003-05-01

We have developed an observatory control system that can be operated in interactive, remote or robotic modes. In interactive and remote mode the observer typically acquires the first object then creates a script through a window interface to complete observations for the rest of the night. The system closes early in the event of bad weather. In robotic mode observations are submitted ahead of time through a web-based interface. We present observations made with a 1.0-m telescope using these methods.

Design of penicillin fermentation process simulation system

NASA Astrophysics Data System (ADS)

Qi, Xiaoyu; Yuan, Zhonghu; Qi, Xiaoxuan; Zhang, Wenqi

2011-10-01

Real-time monitoring for batch process attracts increasing attention. It can ensure safety and provide products with consistent quality. The design of simulation system of batch process fault diagnosis is of great significance. In this paper, penicillin fermentation, a typical non-linear, dynamic, multi-stage batch production process, is taken as the research object. A visual human-machine interactive simulation software system based on Windows operation system is developed. The simulation system can provide an effective platform for the research of batch process fault diagnosis.

Application specific beam profiles: new surface and thin-film refinement processes using beam shaping technologies

NASA Astrophysics Data System (ADS)

Hauschild, Dirk

2017-02-01

Today, the use of laser photons for materials processing is a key technology in nearly all industries. Most of the applications use circular beam shapes with Gaussian intensity distribution that is given by the resonator of the laser or by the power delivery via optical fibre. These beam shapes can be typically used for material removal with cutting or drilling and for selective removal of material layers with ablation processes. In addition to the removal of materials, it is possible to modify and improve the material properties in case the dose of laser photons and the resulting light-material interaction addresses a defined window of energy and dwell-time. These process windows have typically dwell-times between µs and s because of using sintering, melting, thermal diffusion or photon induced chemical and physical reaction mechanisms. Using beam shaping technologies the laser beam profiles can be adapted to the material properties and time-temperature and the space-temperature envelopes can be modified to enable selective annealing or crystallization of layers or surfaces. Especially the control of the process energy inside the beam and at its edges opens a large area of laser applications that can be addressed only with an optimized spatial and angular beam profile with down to sub-percent intensity variation used in e.g. immersion lithography tools with ArF laser sources. LIMO will present examples for new beam shapes and related material refinement processes even on large surfaces and give an overview about new mechanisms in laser material processing for current and coming industrial applications.

Determining the frequency of open windows in motor vehicles: a pilot study using a video camera in Houston, Texas during high temperature conditions.

PubMed

Long, Tom; Johnson, Ted; Ollison, Will

2002-05-01

Researchers have developed a variety of computer-based models to estimate population exposure to air pollution. These models typically estimate exposures by simulating the movement of specific population groups through defined microenvironments. Exposures in the motor vehicle microenvironment are significantly affected by air exchange rate, which in turn is affected by vehicle speed, window position, vent status, and air conditioning use. A pilot study was conducted in Houston, Texas, during September 2000 for a specific set of weather, vehicle speed, and road type conditions to determine whether useful information on the position of windows, sunroofs, and convertible tops could be obtained through the use of video cameras. Monitoring was conducted at three sites (two arterial roads and one interstate highway) on the perimeter of Harris County located in or near areas not subject to mandated Inspection and Maintenance programs. Each site permitted an elevated view of vehicles as they proceeded through a turn, thereby exposing all windows to the stationary video camera. Five videotaping sessions were conducted over a two-day period in which the Heat Index (HI)-a function of temperature and humidity-varied from 80 to 101 degrees F and vehicle speed varied from 30 to 74 mph. The resulting videotapes were processed to create a master database listing vehicle-specific data for site location, date, time, vehicle type (e.g., minivan), color, window configuration (e.g., four windows and sunroof), number of windows in each of three position categories (fully open, partially open, and closed), HI, and speed. Of the 758 vehicles included in the database, 140 (18.5 percent) were labeled as "open," indicating a window, sunroof, or convertible top was fully or partially open. The results of a series of stepwise linear regression analyses indicated that the probability of a vehicle in the master database being "open" was weakly affected by time of day, vehicle type, vehicle color, vehicle speed, and HI. In particular, open windows occurred more frequently when vehicle speed was less than 50 mph during periods when HI exceeded 99.9 degrees F and the vehicle was a minivan or passenger van. Overall, the pilot study demonstrated that data on factors affecting vehicle window position could be acquired through a relatively simple experimental protocol using a single video camera. Limitations of the study requiring further research include the inability to determine the status of the vehicle air conditioning system; lack of a wide range of weather, vehicle speed, and road type conditions; and the need to exclude some vehicles from statistical analyses due to ambiguous window positions.

A longer vernal window: the role of winter coldness and snowpack in driving spring transitions and lags.

PubMed

Contosta, Alexandra R; Adolph, Alden; Burchsted, Denise; Burakowski, Elizabeth; Green, Mark; Guerra, David; Albert, Mary; Dibb, Jack; Martin, Mary; McDowell, William H; Routhier, Michael; Wake, Cameron; Whitaker, Rachel; Wollheim, Wilfred

2017-04-01

Climate change is altering the timing and duration of the vernal window, a period that marks the end of winter and the start of the growing season when rapid transitions in ecosystem energy, water, nutrient, and carbon dynamics take place. Research on this period typically captures only a portion of the ecosystem in transition and focuses largely on the dates by which the system wakes up. Previous work has not addressed lags between transitions that represent delays in energy, water, nutrient, and carbon flows. The objectives of this study were to establish the sequence of physical and biogeochemical transitions and lags during the vernal window period and to understand how climate change may alter them. We synthesized observations from a statewide sensor network in New Hampshire, USA, that concurrently monitored climate, snow, soils, and streams over a three-year period and supplemented these observations with climate reanalysis data, snow data assimilation model output, and satellite spectral data. We found that some of the transitions that occurred within the vernal window were sequential, with air temperatures warming prior to snow melt, which preceded forest canopy closure. Other transitions were simultaneous with one another and had zero-length lags, such as snowpack disappearance, rapid soil warming, and peak stream discharge. We modeled lags as a function of both winter coldness and snow depth, both of which are expected to decline with climate change. Warmer winters with less snow resulted in longer lags and a more protracted vernal window. This lengthening of individual lags and of the entire vernal window carries important consequences for the thermodynamics and biogeochemistry of ecosystems, both during the winter-to-spring transition and throughout the rest of the year. © 2016 The Authors Global Change Biology Published by John Wiley & Sons Ltd.

Optimization of simultaneous tritium–radiocarbon internal gas proportional counting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonicalzi, R. M.; Aalseth, C. E.; Day, A. R.

Specific environmental applications can benefit from dual tritium and radiocarbon measurements in a single compound. Assuming typical environmental levels, it is often the low tritium activity relative to the higher radiocarbon activity that limits the dual measurement. In this paper, we explore the parameter space for a combined tritium and radiocarbon measurement using a methane sample mixed with an argon fill gas in low-background proportional counters of a specific design. We present an optimized methane percentage, detector fill pressure, and analysis energy windows to maximize measurement sensitivity while minimizing count time. The final optimized method uses a 9-atm fill ofmore » P35 (35% methane, 65% argon), and a tritium analysis window from 1.5 to 10.3 keV, which stops short of the tritium beta decay endpoint energy of 18.6 keV. This method optimizes tritium counting efficiency while minimizing radiocarbon beta decay interference.« less

The SSABLE system - Automated archive, catalog, browse and distribution of satellite data in near-real time

NASA Technical Reports Server (NTRS)

Simpson, James J.; Harkins, Daniel N.

1993-01-01

Historically, locating and browsing satellite data has been a cumbersome and expensive process. This has impeded the efficient and effective use of satellite data in the geosciences. SSABLE is a new interactive tool for the archive, browse, order, and distribution of satellite date based upon X Window, high bandwidth networks, and digital image rendering techniques. SSABLE provides for automatically constructing relational database queries to archived image datasets based on time, data, geographical location, and other selection criteria. SSABLE also provides a visual representation of the selected archived data for viewing on the user's X terminal. SSABLE is a near real-time system; for example, data are added to SSABLE's database within 10 min after capture. SSABLE is network and machine independent; it will run identically on any machine which satisfies the following three requirements: 1) has a bitmapped display (monochrome or greater); 2) is running the X Window system; and 3) is on a network directly reachable by the SSABLE system. SSABLE has been evaluated at over 100 international sites. Network response time in the United States and Canada varies between 4 and 7 s for browse image updates; reported transmission times to Europe and Australia typically are 20-25 s.

Evaluation of Cellular Shades in the PNNL Lab Homes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petersen, Joseph M.; Sullivan, Greg; Cort, Katherine A.

This report examines the energy performance of cellular shade window coverings in a matched pair of all-electric, factory-built “Lab Homes” located on the Pacific Northwest National Laboratory (PNNL) campus in Richland, Washington. The 1500-square-foot homes were identical in construction and baseline performance, which allowed any difference in energy and thermal performance between the baseline home and the experimental home to be attributed to the retrofit technology installed in the experimental home. To assess the performance of high efficiency window attachments in a residential retrofit application, the building shell air leakage, energy use, and interior temperatures of each home were comparedmore » during the 2015 -2016 winter heating and summer cooling seasons. Hunter Douglas Duette® Architella® Trielle™ opaque honeycomb “cellular” shades were installed over double-pane clear-glass, aluminum-frame primary windows in the experimental home and were compared to identical primary windows with no window coverings and with standard typical white vinyl horizontal blind window coverings in the baseline home.« less

Engineered Surfaces to Control Secondary Electron Yield for Multipactor Suppression

DTIC Science & Technology

2017-09-14

Radio Engineers ( IRE ) Transactions on Electron Devices. The first paper , published by Preist and Talcott, examined damage to RF windows in klystrons...Secondary electron emission data for aluminum referenced by Hatch in his 1961 paper showing a typical SEY (δ) curve (top) and typical energy...83 IRE : Institute of Radio Engineers

Biased random key genetic algorithm with insertion and gender selection for capacitated vehicle routing problem with time windows

NASA Astrophysics Data System (ADS)

Rochman, Auliya Noor; Prasetyo, Hari; Nugroho, Munajat Tri

2017-06-01

Vehicle Routing Problem (VRP) often occurs when the manufacturers need to distribute their product to some customers/outlets. The distribution process is typically restricted by the capacity of the vehicle and the working hours at the distributor. This type of VRP is also known as Capacitated Vehicle Routing Problem with Time Windows (CVRPTW). A Biased Random Key Genetic Algorithm (BRKGA) was designed and coded in MATLAB to solve the CVRPTW case of soft drink distribution. The standard BRKGA was then modified by applying chromosome insertion into the initial population and defining chromosome gender for parent undergoing crossover operation. The performance of the established algorithms was then compared to a heuristic procedure for solving a soft drink distribution. Some findings are revealed (1) the total distribution cost of BRKGA with insertion (BRKGA-I) results in a cost saving of 39% compared to the total cost of heuristic method, (2) BRKGA with the gender selection (BRKGA-GS) could further improve the performance of the heuristic method. However, the BRKGA-GS tends to yield worse results compared to that obtained from the standard BRKGA.

Lensing of Fast Radio Bursts as a Probe of Compact Dark Matter.

PubMed

Muñoz, Julian B; Kovetz, Ely D; Dai, Liang; Kamionkowski, Marc

2016-08-26

The possibility that part of the dark matter is made of massive compact halo objects (MACHOs) remains poorly constrained over a wide range of masses, and especially in the 20-100  M_{⊙} window. We show that strong gravitational lensing of extragalactic fast radio bursts (FRBs) by MACHOs of masses larger than ∼20  M_{⊙} would result in repeated FRBs with an observable time delay. Strong lensing of a FRB by a lens of mass M_{L} induces two images, separated by a typical time delay ∼few×(M_{L}/30  M_{⊙})  msec. Considering the expected FRB detection rate by upcoming experiments, such as canadian hydrogen intensity mapping experiment (CHIME), of 10^{4} FRBs per year, we should observe from tens to hundreds of repeated bursts yearly, if MACHOs in this window make up all the dark matter. A null search for echoes with just 10^{4} FRBs would constrain the fraction f_{DM} of dark matter in MACHOs to f_{DM}≲0.08 for M_{L}≳20  M_{⊙}.

Parent-reported Temperament Trajectories among Infant Siblings of Children with Autism

PubMed Central

del Rosario, Mithi; Gillespie-Lynch, Kristen; Johnson, Scott; Sigman, Marian; Hutman, Ted

2013-01-01

Temperament atypicalities have been documented in infancy and early development in children who develop autism spectrum disorders (ASD). The current study investigates whether there are differences in developmental trajectories of temperament between infants and toddlers with and without ASD. Parents of infant siblings of children with autism completed the Carey Temperament Scales about their child at 6, 12, 18, 24, and 36 months of age. Temperament trajectories of children with ASD reflected increases over time in activity level, and decreasing adaptability and approach behaviors relative to high-risk typically developing children. This study is the first to compare temperament trajectories between high-risk typically developing infants and infants subsequently diagnosed with ASD in the developmental window when overt symptoms of ASD first emerge. PMID:23820765

Quantify work load and muscle functional activation patterns in neck-shoulder muscles of female sewing machine operators using surface electromyogram.

PubMed

Zhang, Fei-Ruo; He, Li-Hua; Wu, Shan-Shan; Li, Jing-Yun; Ye, Kang-Pin; Wang, Sheng

2011-11-01

Work-related musculoskeletal disorders (WMSDs) have high prevalence in sewing machine operators employed in the garment industry. Long work duration, sustained low level work and precise hand work are the main risk factors of neck-shoulder disorders for sewing machine operators. Surface electromyogram (sEMG) offers a valuable tool to determine muscle activity (internal exposure) and quantify muscular load (external exposure). During sustained and/or repetitive muscle contractions, typical changes of muscle fatigue in sEMG, as an increase in amplitude or a decrease as a shift in spectrum towards lower frequencies, can be observed. In this paper, we measured and quantified the muscle load and muscular activity patterns of neck-shoulder muscles in female sewing machine operators during sustained sewing machine operating tasks using sEMG. A total of 18 healthy women sewing machine operators volunteered to participate in this study. Before their daily sewing machine operating task, we measured the maximal voluntary contractions (MVC) and 20%MVC of bilateral cervical erector spinae (CES) and upper trapezius (UT) respectively, then the sEMG signals of bilateral UT and CES were monitored and recorded continuously during 200 minutes of sustained sewing machine operating simultaneously which equals to 20 time windows with 10 minutes as one time window. After 200 minutes' work, we retest 20%MVC of four neck-shoulder muscles and recorded the sEMG signals. Linear analysis, including amplitude probability distribution frequency (APDF), amplitude analysis parameters such as roof mean square (RMS) and spectrum analysis parameter as median frequency (MF), were used to calculate and indicate muscle load and muscular activity of bilateral CES and UT. During 200 minutes of sewing machine operating, the median load for the left cervical erector spinae (LCES), right cervical erector spinae (RCES), left upper trapezius (LUT) and right upper trapezius (RUT) were 6.78%MVE, 6.94%MVE, 6.47%MVE and 5.68%MVE, respectively. Work load of right muscles are significantly higher than that of the left muscles (P < 0.05); sEMG signal analysis of isometric contractions indicated that the amplitude value before operating was significantly higher than that of after work (P < 0.01), and the spectrum value of bilateral CES and UT were significantly lower than those of after work (P < 0.01); according to the sEMG signal data of 20 time windows, with operating time pass by, the muscle activity patterns of bilateral CES and UT showed dynamic changes, the maximal amplitude of LCES, RCES, LUT occurred at the 20th time window, RUT at 16th time window, spectrum analysis showed that the lower value happened at 7th, 16th, 20th time windows. Female sewing machine operators were exposed to high sustained static load on bilateral neck-shoulder muscles; left neck and shoulder muscles were held in more static positions; the 7th, 16th, and 20th time windows were muscle fatigue period that ergonomics intervention can protocol at these periods.

Analysis of click-evoked otoacoustic emissions by concentration of frequency and time: Preliminary results from normal hearing and Ménière's disease ears

NASA Astrophysics Data System (ADS)

Liu, Tzu-Chi; Wu, Hau-Tieng; Chen, Ya-Hui; Chen, Ya-Han; Fang, Te-Yung; Wang, Pa-Chun; Liu, Yi-Wen

2018-05-01

The presence of click-evoked (CE) otoacoustic emissions (OAEs) has been clinically accepted as an indicator of normal cochlear processing of sounds. For treatment and diagnostic purposes, however, clinicians do not typically pay attention to the detailed spectrum and waveform of CEOAEs. A possible reason is due to the lack of noise-robust signal processing tools to estimate physiologically meaningful time-frequency properties of CEOAEs, such as the latency of spectral components. In this on-going study, we applied a modern tool called concentration of frequency and time (ConceFT, [1]) to analyze CEOAE waveforms. Randomly combined orthogonal functions are used as windowing functions for time-frequency analysis. The resulting spectrograms are subject to nonlinear time-frequency reassignment so as to enhance the concentration of time-varying sinusoidal components. The results after reassignment could be further averaged across the random choice of windows. CEOAE waveforms are acquired by a linear averaging paradigm, and longitudinal data are currently being collected from patients with Ménière's disease (MD) and a control group of normal hearing subjects. When CEOAE is present, the ConceFT plots show traces of decreasing but fluctuating instantaneous frequency against time. For comparison purposes, same processing methods are also applied to analyze CEOAE data from cochlear mechanics simulation.

Wavenumber selection based analysis in Raman spectroscopy improves skin cancer diagnostic specificity at high sensitivity levels (Conference Presentation)

NASA Astrophysics Data System (ADS)

Zhao, Jianhua; Zeng, Haishan; Kalia, Sunil; Lui, Harvey

2017-02-01

Background: Raman spectroscopy is a non-invasive optical technique which can measure molecular vibrational modes within tissue. A large-scale clinical study (n = 518) has demonstrated that real-time Raman spectroscopy could distinguish malignant from benign skin lesions with good diagnostic accuracy; this was validated by a follow-up independent study (n = 127). Objective: Most of the previous diagnostic algorithms have typically been based on analyzing the full band of the Raman spectra, either in the fingerprint or high wavenumber regions. Our objective in this presentation is to explore wavenumber selection based analysis in Raman spectroscopy for skin cancer diagnosis. Methods: A wavenumber selection algorithm was implemented using variably-sized wavenumber windows, which were determined by the correlation coefficient between wavenumbers. Wavenumber windows were chosen based on accumulated frequency from leave-one-out cross-validated stepwise regression or least and shrinkage selection operator (LASSO). The diagnostic algorithms were then generated from the selected wavenumber windows using multivariate statistical analyses, including principal component and general discriminant analysis (PC-GDA) and partial least squares (PLS). A total cohort of 645 confirmed lesions from 573 patients encompassing skin cancers, precancers and benign skin lesions were included. Lesion measurements were divided into training cohort (n = 518) and testing cohort (n = 127) according to the measurement time. Result: The area under the receiver operating characteristic curve (ROC) improved from 0.861-0.891 to 0.891-0.911 and the diagnostic specificity for sensitivity levels of 0.99-0.90 increased respectively from 0.17-0.65 to 0.20-0.75 by selecting specific wavenumber windows for analysis. Conclusion: Wavenumber selection based analysis in Raman spectroscopy improves skin cancer diagnostic specificity at high sensitivity levels.

Nonuniform Effects of Reinstatement within the Time Window

ERIC Educational Resources Information Center

Galluccio, Llissa; Rovee-Collier, Carolyn

2006-01-01

A time window is a limited period after an event initially occurs in which additional information can be integrated with the memory of that event. It shuts when the memory is forgotten. The time window hypothesis holds that the impact of a manipulation at different points within the time window is nonuniform. In two operant conditioning…

Due-Window Assignment Scheduling with Variable Job Processing Times

PubMed Central

Wu, Yu-Bin

2015-01-01

We consider a common due-window assignment scheduling problem jobs with variable job processing times on a single machine, where the processing time of a job is a function of its position in a sequence (i.e., learning effect) or its starting time (i.e., deteriorating effect). The problem is to determine the optimal due-windows, and the processing sequence simultaneously to minimize a cost function includes earliness, tardiness, the window location, window size, and weighted number of tardy jobs. We prove that the problem can be solved in polynomial time. PMID:25918745

A critical time window for organismal interactions in a pelagic ecosystem.

PubMed

Benoit-Bird, Kelly J; McManus, Margaret A

2014-01-01

To measure organismal coherence in a pelagic ecosystem, we used moored sensors to describe the vertical dynamics of each step in the food chain in shelf waters off the west shore of Oahu, Hawaii. Horizontally extensive, intense aggregations of phytoplankton, zooplankton, and micronekton exhibited strong diel patterns in abundance and vertical distribution, resulting in a highly variable potential for interaction amongst trophic levels. Only around dusk did zooplankton layers overlap with phytoplankton layers. Shortly after sunset, micronekton ascended from the deep, aggregating on the island's shelf. Short-lived departures in migration patterns were detected in depth, vertical distribution, density, and total abundance of micronekton when zooplankton layers were present with typical patterns resuming within one hour. Layers of zooplankton began to disappear within 20 minutes of the arrival of micronekton with no layers present after 50 minutes. The effects of zooplankton layers cascaded even further up the food chain, affecting many behaviors of dolphins observed at dusk including their depth, group size, and inter-individual spacing. As a result of these changes in behavior, during a 30-minute window just after dusk, the number of feeding events observed for each dolphin and consequently the feeding time for each individual more than doubled when zooplankton layers were present. Dusk is a critical period for interactions amongst species in this system from phytoplankton to top predators. Our observations that short time windows can drive the structure and function of a complex suite of organisms highlight the importance of explicitly adding a temporal dimension at a scale relevant to individual organisms to our descriptions of heterogeneity in ocean ecosystems.

Wavelet-based clustering of resting state MRI data in the rat.

PubMed

Medda, Alessio; Hoffmann, Lukas; Magnuson, Matthew; Thompson, Garth; Pan, Wen-Ju; Keilholz, Shella

2016-01-01

While functional connectivity has typically been calculated over the entire length of the scan (5-10min), interest has been growing in dynamic analysis methods that can detect changes in connectivity on the order of cognitive processes (seconds). Previous work with sliding window correlation has shown that changes in functional connectivity can be observed on these time scales in the awake human and in anesthetized animals. This exciting advance creates a need for improved approaches to characterize dynamic functional networks in the brain. Previous studies were performed using sliding window analysis on regions of interest defined based on anatomy or obtained from traditional steady-state analysis methods. The parcellation of the brain may therefore be suboptimal, and the characteristics of the time-varying connectivity between regions are dependent upon the length of the sliding window chosen. This manuscript describes an algorithm based on wavelet decomposition that allows data-driven clustering of voxels into functional regions based on temporal and spectral properties. Previous work has shown that different networks have characteristic frequency fingerprints, and the use of wavelets ensures that both the frequency and the timing of the BOLD fluctuations are considered during the clustering process. The method was applied to resting state data acquired from anesthetized rats, and the resulting clusters agreed well with known anatomical areas. Clusters were highly reproducible across subjects. Wavelet cross-correlation values between clusters from a single scan were significantly higher than the values from randomly matched clusters that shared no temporal information, indicating that wavelet-based analysis is sensitive to the relationship between areas. Copyright © 2015 Elsevier Inc. All rights reserved.

The late positive potential as a marker of motivated attention to underweight bodies in girls with anorexia nervosa.

PubMed

Horndasch, Stefanie; Heinrich, Hartmut; Kratz, Oliver; Moll, Gunther H

2012-12-01

In anorexia nervosa (AN), aspects of motivational salience and reward are increasingly discussed. Event related potentials, particularly the late positive potential (LPP), have been investigated as a marker for motivational salience of stimuli, for example in addictive disorders. The aim of this study was to assess the LPP as a possible indicator of motivated attention towards disease-specific pictures of underweight female bodies in adolescents with AN in comparison to typically developing (TD) adolescent girls. 13 girls with AN and 18 TD adolescent girls (aged 12 to 18 years) viewed pictures of underweight, normal-weight and overweight women while EEG activity was recorded. An earlier (450-680 ms after stimulus onset) as well as a later time window (850-1250 ms after stimulus onset) of the LPP were examined for the different picture categories. Participants were also asked to rate subjective emotions (fear, disgust, happiness) elicited by the pictures. Subjective ratings showed no differential experience of emotions for the two groups. For AN patients, highest LPP amplitudes were found for underweight women in the earlier as well as in the later time window. In TD girls, highest amplitudes for pictures of overweight women were observed in the earlier time window. A differential LPP pattern for girls with AN and TD girls when viewing pictures of women's bodies of different weight categories was obtained. Highest amplitudes in AN patients for pictures of underweight women may reflect motivational significance of strongly underweight body shapes. Copyright © 2012 Elsevier Inc. All rights reserved.

Real-time monitoring of a coffee roasting process with near infrared spectroscopy using multivariate statistical analysis: A feasibility study.

PubMed

Catelani, Tiago A; Santos, João Rodrigo; Páscoa, Ricardo N M J; Pezza, Leonardo; Pezza, Helena R; Lopes, João A

2018-03-01

This work proposes the use of near infrared (NIR) spectroscopy in diffuse reflectance mode and multivariate statistical process control (MSPC) based on principal component analysis (PCA) for real-time monitoring of the coffee roasting process. The main objective was the development of a MSPC methodology able to early detect disturbances to the roasting process resourcing to real-time acquisition of NIR spectra. A total of fifteen roasting batches were defined according to an experimental design to develop the MSPC models. This methodology was tested on a set of five batches where disturbances of different nature were imposed to simulate real faulty situations. Some of these batches were used to optimize the model while the remaining was used to test the methodology. A modelling strategy based on a time sliding window provided the best results in terms of distinguishing batches with and without disturbances, resourcing to typical MSPC charts: Hotelling's T 2 and squared predicted error statistics. A PCA model encompassing a time window of four minutes with three principal components was able to efficiently detect all disturbances assayed. NIR spectroscopy combined with the MSPC approach proved to be an adequate auxiliary tool for coffee roasters to detect faults in a conventional roasting process in real-time. Copyright © 2017 Elsevier B.V. All rights reserved.

Occupant-responsive optimal control of smart facade systems

NASA Astrophysics Data System (ADS)

Park, Cheol-Soo

Windows provide occupants with daylight, direct sunlight, visual contact with the outside and a feeling of openness. Windows enable the use of daylighting and offer occupants a outside view. Glazing may also cause a number of problems: undesired heat gain/loss in winter. An over-lit window can cause glare, which is another major complaint by occupants. Furthermore, cold or hot window surfaces induce asymmetric thermal radiation which can result in thermal discomfort. To reduce the potential problems of window systems, double skin facades and airflow window systems have been introduced in the 1970s. They typically contain interstitial louvers and ventilation openings. The current problem with double skin facades and airflow windows is that their operation requires adequate dynamic control to reach their expected performance. Many studies have recognized that only an optimal control enables these systems to truly act as active energy savers and indoor environment controllers. However, an adequate solution for this dynamic optimization problem has thus far not been developed. The primary objective of this study is to develop occupant responsive optimal control of smart facade systems. The control could be implemented as a smart controller that operates the motorized Venetian blind system and the opening ratio of ventilation openings. The objective of the control is to combine the benefits of large windows with low energy demands for heating and cooling, while keeping visual well-being and thermal comfort at an optimal level. The control uses a simulation model with an embedded optimization routine that allows occupant interaction via the Web. An occupant can access the smart controller from a standard browser and choose a pre-defined mode (energy saving mode, visual comfort mode, thermal comfort mode, default mode, nighttime mode) or set a preferred mode (user-override mode) by moving preference sliders on the screen. The most prominent feature of these systems is the capability of dynamically reacting to the environmental input data through real-time optimization. The proposed occupant responsive optimal control of smart facade systems could provide a breakthrough in this under-developed area and lead to a renewed interest in smart facade systems.

Precision Departure Release Capability (PDRC) Final Report

NASA Technical Reports Server (NTRS)

Engelland, Shawn A.; Capps, Richard; Day, Kevin Brian; Kistler, Matthew Stephen; Gaither, Frank; Juro, Greg

2013-01-01

After takeoff, aircraft must merge into en route (Center) airspace traffic flows that may be subject to constraints that create localized demand/capacity imbalances. When demand exceeds capacity, Traffic Management Coordinators (TMCs) and Frontline Managers (FLMs) often use tactical departure scheduling to manage the flow of departures into the constrained Center traffic flow. Tactical departure scheduling usually involves a Call for Release (CFR) procedure wherein the Tower must call the Center to coordinate a release time prior to allowing the flight to depart. In present-day operations release times are computed by the Center Traffic Management Advisor (TMA) decision support tool, based upon manual estimates of aircraft ready time verbally communicated from the Tower to the Center. The TMA-computed release time is verbally communicated from the Center back to the Tower where it is relayed to the Local controller as a release window that is typically three minutes wide. The Local controller will manage the departure to meet the coordinated release time window. Manual ready time prediction and verbal release time coordination are labor intensive and prone to inaccuracy. Also, use of release time windows adds uncertainty to the tactical departure process. Analysis of more than one million flights from January 2011 indicates that a significant number of tactically scheduled aircraft missed their en route slot due to ready time prediction uncertainty. Uncertainty in ready time estimates may result in missed opportunities to merge into constrained en route flows and lead to lost throughput. Next Generation Air Transportation System plans call for development of Tower automation systems capable of computing surface trajectory-based ready time estimates. NASA has developed the Precision Departure Release Capability (PDRC) concept that improves tactical departure scheduling by automatically communicating surface trajectory-based ready time predictions and departure runway assignments to the Center scheduling tool. The PDRC concept also incorporates earlier NASA and FAA research into automation-assisted CFR coordination. The PDRC concept reduces uncertainty by automatically communicating coordinated release times with seconds-level precision enabling TMCs and FLMs to work with target times rather than windows. NASA has developed a PDRC prototype system that integrates the Center's TMA system with a research prototype Tower decision support tool. A two-phase field evaluation was conducted at NASA's North Texas Research Station in Dallas/Fort Worth. The field evaluation validated the PDRC concept and demonstrated reduced release time uncertainty while being used for tactical departure scheduling of more than 230 operational flights over 29 weeks of operations. This paper presents research results from the PDRC research activity. Companion papers present the Concept of Operations and a Technology Description.

Precision Departure Release Capability (PDRC): NASA to FAA Research Transition

NASA Technical Reports Server (NTRS)

Engelland, Shawn; Davis, Thomas J.

2013-01-01

After takeoff, aircraft must merge into en route (Center) airspace traffic flows which may be subject to constraints that create localized demand-capacity imbalances. When demand exceeds capacity, Traffic Management Coordinators (TMCs) and Frontline Managers (FLMs) often use tactical departure scheduling to manage the flow of departures into the constrained Center traffic flow. Tactical departure scheduling usually involves use of a Call for Release (CFR) procedure wherein the Tower must call the Center to coordinate a release time prior to allowing the flight to depart. In present-day operations release times are computed by the Center Traffic Management Advisor (TMA) decision support tool based upon manual estimates of aircraft ready time verbally communicated from the Tower to the Center. The TMA-computed release time is verbally communicated from the Center back to the Tower where it is relayed to the Local controller as a release window that is typically three minutes wide. The Local controller will manage the departure to meet the coordinated release time window. Manual ready time prediction and verbal release time coordination are labor intensive and prone to inaccuracy. Also, use of release time windows adds uncertainty to the tactical departure process. Analysis of more than one million flights from January 2011 indicates that a significant number of tactically scheduled aircraft missed their en route slot due to ready time prediction uncertainty. Uncertainty in ready time estimates may result in missed opportunities to merge into constrained en route flows and lead to lost throughput. Next Generation Air Transportation System plans call for development of Tower automation systems capable of computing surface trajectory-based ready time estimates. NASA has developed the Precision Departure Release Capability (PDRC) concept that improves tactical departure scheduling by automatically communicating surface trajectory-based ready time predictions and departure runway assignments to the Center scheduling tool. The PDRC concept also incorporates earlier NASA and FAA research into automation-assisted CFR coordination. The PDRC concept reduces uncertainty by automatically communicating coordinated release times with seconds-level precision enabling TMCs and FLMs to work with target times rather than windows. NASA has developed a PDRC prototype system that integrates the Center's TMA system with a research prototype Tower decision support tool. A two-phase field evaluation was conducted at NASA's North Texas Research Station in Dallas-Fort Worth. The field evaluation validated the PDRC concept and demonstrated reduced release time uncertainty while being used for tactical departure scheduling of more than 230 operational flights over 29 weeks of operations.

Precision Departure Release Capability (PDRC) Technology Description

NASA Technical Reports Server (NTRS)

Engelland, Shawn A.; Capps, Richard; Day, Kevin; Robinson, Corissia; Null, Jody R.

2013-01-01

After takeoff, aircraft must merge into en route (Center) airspace traffic flows which may be subject to constraints that create localized demand-capacity imbalances. When demand exceeds capacity, Traffic Management Coordinators (TMCs) often use tactical departure scheduling to manage the flow of departures into the constrained Center traffic flow. Tactical departure scheduling usually involves use of a Call for Release (CFR) procedure wherein the Tower must call the Center TMC to coordinate a release time prior to allowing the flight to depart. In present-day operations release times are computed by the Center Traffic Management Advisor (TMA) decision support tool based upon manual estimates of aircraft ready time verbally communicated from the Tower to the Center. The TMA-computed release is verbally communicated from the Center back to the Tower where it is relayed to the Local controller as a release window that is typically three minutes wide. The Local controller will manage the departure to meet the coordinated release time window. Manual ready time prediction and verbal release time coordination are labor intensive and prone to inaccuracy. Also, use of release time windows adds uncertainty to the tactical departure process. Analysis of more than one million flights from January 2011 indicates that a significant number of tactically scheduled aircraft missed their en route slot due to ready time prediction uncertainty. Uncertainty in ready time estimates may result in missed opportunities to merge into constrained en route flows and lead to lost throughput. Next Generation Air Transportation System (NextGen) plans call for development of Tower automation systems capable of computing surface trajectory-based ready time estimates. NASA has developed the Precision Departure Release Capability (PDRC) concept that uses this technology to improve tactical departure scheduling by automatically communicating surface trajectory-based ready time predictions to the Center scheduling tool. The PDRC concept also incorporates earlier NASA and FAA research into automation-assisted CFR coordination. The PDRC concept helps reduce uncertainty by automatically communicating coordinated release times with seconds-level precision enabling TMCs to work with target times rather than windows. NASA has developed a PDRC prototype system that integrates the Center's TMA system with a research prototype Tower decision support tool. A two-phase field evaluation was conducted at NASA's North Texas Research Station (NTX) in Dallas-Fort Worth. The field evaluation validated the PDRC concept and demonstrated reduced release time uncertainty while being used for tactical departure scheduling of more than 230 operational flights over 29 weeks of operations. This paper presents the Technology Description. Companion papers include the Final Report and a Concept of Operations.

Precision Departure Release Capability (PDRC) Concept of Operations

NASA Technical Reports Server (NTRS)

Engelland, Shawn; Capps, Richard A.; Day, Kevin Brian

2013-01-01

After takeoff, aircraft must merge into en route (Center) airspace traffic flows which may be subject to constraints that create localized demandcapacity imbalances. When demand exceeds capacity Traffic Management Coordinators (TMCs) often use tactical departure scheduling to manage the flow of departures into the constrained Center traffic flow. Tactical departure scheduling usually involves use of a Call for Release (CFR) procedure wherein the Tower must call the Center TMC to coordinate a release time prior to allowing the flight to depart. In present-day operations release times are computed by the Center Traffic Management Advisor (TMA) decision support tool based upon manual estimates of aircraft ready time verbally communicated from the Tower to the Center. The TMA-computed release is verbally communicated from the Center back to the Tower where it is relayed to the Local controller as a release window that is typically three minutes wide. The Local controller will manage the departure to meet the coordinated release time window. Manual ready time prediction and verbal release time coordination are labor intensive and prone to inaccuracy. Also, use of release time windows adds uncertainty to the tactical departure process. Analysis of more than one million flights from January 2011 indicates that a significant number of tactically scheduled aircraft missed their en route slot due to ready time prediction uncertainty. Uncertainty in ready time estimates may result in missed opportunities to merge into constrained en route flows and lead to lost throughput. Next Generation Air Transportation System (NextGen) plans call for development of Tower automation systems capable of computing surface trajectory-based ready time estimates. NASA has developed the Precision Departure Release Capability (PDRC) concept that uses this technology to improve tactical departure scheduling by automatically communicating surface trajectory-based ready time predictions to the Center scheduling tool. The PDRC concept also incorporates earlier NASA and FAA research into automation-assisted CFR coordination. The PDRC concept helps reduce uncertainty by automatically communicating coordinated release times with seconds-level precision enabling TMCs to work with target times rather than windows. NASA has developed a PDRC prototype system that integrates the Center's TMA system with a research prototype Tower decision support tool. A two-phase field evaluation was conducted at NASA's North Texas Research Station (NTX) in DallasFort Worth. The field evaluation validated the PDRC concept and demonstrated reduced release time uncertainty while being used for tactical departure scheduling of more than 230 operational flights over 29 weeks of operations. This paper presents the Concept of Operations. Companion papers include the Final Report and a Technology Description. ? SUBJECT:

Sound isolation performance of interior acoustical sash

NASA Astrophysics Data System (ADS)

Tocci, Gregory

2002-05-01

In existing, as well as new buildings, an interior light of glass mounted on the inside of a prime window is used to improve the sound transmission loss otherwise obtained by the prime window alone. Interior acoustical sash is most often 1/4 in. (6 mm) monolithic or laminated glass, and is typically spaced 3 in. to 6 in. from the glass of the prime window. This paper presents TL data measured at Riverbank Acoustical Laboratories by Solutia (formerly Monsanto) for lightweight prime windows of various types, with and without interior acoustical sash glazed with 1/4 in. laminated glass. The TL data are used to estimate the A-weighted insertion loss of interior acoustical sash when applied to prime windows glazed with lightweight glass for four transportation noise source types-highway traffic, aircraft, electric rail, and diesel rail. The analysis also has been extended to determine the insertion loss expressed as a change in OITC. The data also exhibit the reductions in insertion loss that can result from short-circuiting the interior acoustical sash with the prime window. [Work supported by Solutia, Inc.

Gas Ring-Imagining Cherenkov (GRINCH) Detector for the Super BigBite Spectrometer at Jefferson Lab

NASA Astrophysics Data System (ADS)

Averett, Todd; Wojtsekhowski, Bogdan; Amidouch, Abdellah; Danagoulian, Samuel; Niculescu, Gabriel; Niculescu, Ioana; Jefferson Lab SBS Collaboration Collaboration

2017-01-01

A new gas Cherenkov detector is under construction for the upcoming SuperBigBite spectrometer research program in Hall A at Jefferson Lab. The existing BigBite spectrometer is being upgraded to handle expected increases in event rate and background rate due to the increased luminosity required for the experimental program. The detector will primarily be used to separate good electron events from significant pion and electromagnetic contamination. In contrast to typical gas Cherenkov detectors that use large-diameter photomultiplier tubes and charge integrating ADCs, this detector uses an array of 510 small-diameter tubes that are more than 25x less sensitive to background. Cherenkov radiation clusters will be identified in this array using fast TDCs and a narrow timing window relative to typical ADC gates. In addition, a new FPGA-based DAQ system is being tested to provide a PID trigger using real-time cluster finding. Details of the detector and current status of the project will be presented.

47 CFR 15.323 - Specific requirements for devices operating in the 1920-1930 MHz sub-band.

Code of Federal Regulations, 2010 CFR

2010-10-01

...] (c) Devices must incorporate a mechanism for monitoring the time and spectrum windows that its... transmission, devices must monitor the combined time and spectrum windows in which they intend to transmit for... windows without further monitoring. However, occupation of the same combined time and spectrum windows by...

Fused silica windows for solar receiver applications

NASA Astrophysics Data System (ADS)

Hertel, Johannes; Uhlig, Ralf; Söhn, Matthias; Schenk, Christian; Helsch, Gundula; Bornhöft, Hansjörg

2016-05-01

A comprehensive study of optical and mechanical properties of quartz glass (fused silica) with regard to application in high temperature solar receivers is presented. The dependence of rupture strength on different surface conditions as well as high temperature is analyzed, focussing particularly on damage by devitrification and sandblasting. The influence of typical types of contamination in combination with thermal cycling on the optical properties of fused silica is determined. Cleaning methods are compared regarding effectiveness on contamination-induced degradation for samples with and without antireflective coating. The FEM-aided design of different types of receiver windows and their support structure is presented. A large-scale production process has been developed for producing fused silica dome shaped windows (pressurized window) up to a diameter of 816 mm. Prototypes were successfully pressure-tested in a test bench and certified according to the European Pressure Vessel Directive.

The origin of blue-green window and the propagation of radiation in ocean waters

NASA Astrophysics Data System (ADS)

Reghunath, A. T.; Venkataramanan, V.; Suviseshamuthu, D. Victor; Krishnamohan, R.; Prasad, B. Raghavendra

1991-01-01

A review of the present knowledge about the origin of blue-green window in the attenuation spectrum of ocean waters is presented. The various physical mechanisms which contribute to the formation of the window are dealt separately and discussed. The typical values of attenuation coefficient arising out of the various processes are compiled to obtain the total beam attenuation coefficient. These values are then compared with measured values of attenuation coefficient for ocean waters collected from Arabian sea and Bay of Bengal. The region of minimum attenuation in pure particle-free sea water is found to be at 450 to 500 nm. It is shown that in the presence of suspended particles and chlorophyll, the window shifts to longer wavelength side. Some suggestions for future work in this area are also given in the concluding section.

Errorless Establishment of a Match-to-Sample Form Discrimination in Preschool Children. I. A Modification of Animal Laboratory Procedures for Children, II. A Comparison of Errorless and Trial-and-Error Discrimination. Progress Report.

ERIC Educational Resources Information Center

LeBlanc, Judith M.

A sequence of studies compared two types of discrimination formation: errorless learning and trial-and-error procedures. The subjects were three boys and five girls from a university preschool. The children performed the experimental tasks at a typical match-to-sample apparatus with one sample window above and four match (response) windows below.…

The energy performance of prototype holographic glazings

NASA Astrophysics Data System (ADS)

Papamichael, K.; Beltran, L.; Furler, R.; Lee, E. S.; Selkowitz, S.; Rubin, M.

1993-02-01

We report on the simulation of the energy performance of prototype holographic glazings in commercial office buildings in a California climate. These prototype glazings, installed above conventional side windows, are designed to diffract the transmitted solar radiation and reflect it off the ceiling, providing adequate daylight illumination for typical office tasks up to 10m from the window. In this study, we experimentally determined a comprehensive set of solar-optical properties and characterized the contribution of the prototype holographic glazings to workplane illuminance in a scale model of a typical office space. We then used the scale model measurements to simulate the energy performance of the holographic glazings over the course of an entire year for four window orientations (North, East, South and West) for the inland Los Angeles climate, using the DOE-2.lD building energy analysis computer program. The results of our experimental analyses indicate that these prototype holographic glazings diffract only a small fraction of the incident light. The results of this study indicate that these prototype holographic glazings will not save energy in commercial office buildings. Their performance is very similar to that of clear glass, which, through side windows, cannot efficiently illuminate more than a 4-6 m depth of a building's perimeter, because the cooling penalties due to solar heat gain are greater than the electric lighting savings due to daylighting.

Power strain imaging based on vibro-elastography techniques

NASA Astrophysics Data System (ADS)

Wen, Xu; Salcudean, S. E.

2007-03-01

This paper describes a new ultrasound elastography technique, power strain imaging, based on vibro-elastography (VE) techniques. With this method, tissue is compressed by a vibrating actuator driven by low-pass or band-pass filtered white noise, typically in the 0-20 Hz range. Tissue displacements at different spatial locations are estimated by correlation-based approaches on the raw ultrasound radio frequency signals and recorded in time sequences. The power spectra of these time sequences are computed by Fourier spectral analysis techniques. As the average of the power spectrum is proportional to the squared amplitude of the tissue motion, the square root of the average power over the range of excitation frequencies is used as a measure of the tissue displacement. Then tissue strain is determined by the least squares estimation of the gradient of the displacement field. The computation of the power spectra of the time sequences can be implemented efficiently by using Welch's periodogram method with moving windows or with accumulative windows with a forgetting factor. Compared to the transfer function estimation originally used in VE, the computation of cross spectral densities is not needed, which saves both the memory and computational times. Phantom experiments demonstrate that the proposed method produces stable and operator-independent strain images with high signal-to-noise ratio in real time. This approach has been also tested on a few patient data of the prostate region, and the results are encouraging.

9. Typical 'furnished rooms' overlook the Washington Street alley. Each ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. Typical 'furnished rooms' overlook the Washington Street alley. Each has two double-hung windows that are fitted with roller-shade brackets. The plaster was formulated with lime and is heavily laden with animal hair. Each room is provided with a stove-pipe connection. Credit GADA/MRM. - Stroud Building, 31-33 North Central Avenue, Phoenix, Maricopa County, AZ

Single-machine common/slack due window assignment problems with linear decreasing processing times

NASA Astrophysics Data System (ADS)

Zhang, Xingong; Lin, Win-Chin; Wu, Wen-Hsiang; Wu, Chin-Chia

2017-08-01

This paper studies linear non-increasing processing times and the common/slack due window assignment problems on a single machine, where the actual processing time of a job is a linear non-increasing function of its starting time. The aim is to minimize the sum of the earliness cost, tardiness cost, due window location and due window size. Some optimality results are discussed for the common/slack due window assignment problems and two O(n log n) time algorithms are presented to solve the two problems. Finally, two examples are provided to illustrate the correctness of the corresponding algorithms.

Oral Health: A Window to Your Overall Health

MedlinePlus

... might contribute to various diseases and conditions, including: Endocarditis. Endocarditis is an infection of the inner lining of your heart (endocardium). Endocarditis typically occurs when bacteria or other germs from ...

Roof Overhangs for Solar Houses

NASA Technical Reports Server (NTRS)

Gracey, W.

1985-01-01

Convenient graphical method determines both width and vertical position of overhangs for standard wall section having "typical" window arrangement. Overhangs for this wall section determined for two extremes of latitude in United States.

Global field synchronization in gamma range of the sleep EEG tracks sleep depth: Artifact introduced by a rectangular analysis window.

PubMed

Rusterholz, Thomas; Achermann, Peter; Dürr, Roland; Koenig, Thomas; Tarokh, Leila

2017-06-01

Investigating functional connectivity between brain networks has become an area of interest in neuroscience. Several methods for investigating connectivity have recently been developed, however, these techniques need to be applied with care. We demonstrate that global field synchronization (GFS), a global measure of phase alignment in the EEG as a function of frequency, must be applied considering signal processing principles in order to yield valid results. Multichannel EEG (27 derivations) was analyzed for GFS based on the complex spectrum derived by the fast Fourier transform (FFT). We examined the effect of window functions on GFS, in particular of non-rectangular windows. Applying a rectangular window when calculating the FFT revealed high GFS values for high frequencies (>15Hz) that were highly correlated (r=0.9) with spectral power in the lower frequency range (0.75-4.5Hz) and tracked the depth of sleep. This turned out to be spurious synchronization. With a non-rectangular window (Tukey or Hanning window) these high frequency synchronization vanished. Both, GFS and power density spectra significantly differed for rectangular and non-rectangular windows. Previous papers using GFS typically did not specify the applied window and may have used a rectangular window function. However, the demonstrated impact of the window function raises the question of the validity of some previous findings at higher frequencies. We demonstrated that it is crucial to apply an appropriate window function for determining synchronization measures based on a spectral approach to avoid spurious synchronization in the beta/gamma range. Copyright © 2017 Elsevier B.V. All rights reserved.

An Analysis of Peer-Reviewed Scores and Impact Factors with Different Citation Time Windows: A Case Study of 28 Ophthalmologic Journals

PubMed Central

Liu, Xue-Li; Gai, Shuang-Shuang; Zhang, Shi-Le; Wang, Pu

2015-01-01

Background An important attribute of the traditional impact factor was the controversial 2-year citation window. So far, several scholars have proposed using different citation time windows for evaluating journals. However, there is no confirmation whether a longer citation time window would be better. How did the journal evaluation effects of 3IF, 4IF, and 6IF comparing with 2IF and 5IF? In order to understand these questions, we made a comparative study of impact factors with different citation time windows with the peer-reviewed scores of ophthalmologic journals indexed by Science Citation Index Expanded (SCIE) database. Methods The peer-reviewed scores of 28 ophthalmologic journals were obtained through a self-designed survey questionnaire. Impact factors with different citation time windows (including 2IF, 3IF, 4IF, 5IF, and 6IF) of 28 ophthalmologic journals were computed and compared in accordance with each impact factor’s definition and formula, using the citation analysis function of the Web of Science (WoS) database. An analysis of the correlation between impact factors with different citation time windows and peer-reviewed scores was carried out. Results Although impact factor values with different citation time windows were different, there was a high level of correlation between them when it came to evaluating journals. In the current study, for ophthalmologic journals’ impact factors with different time windows in 2013, 3IF and 4IF seemed the ideal ranges for comparison, when assessed in relation to peer-reviewed scores. In addition, the 3-year and 4-year windows were quite consistent with the cited peak age of documents published by ophthalmologic journals. Research Limitations Our study is based on ophthalmology journals and we only analyze the impact factors with different citation time window in 2013, so it has yet to be ascertained whether other disciplines (especially those with a later cited peak) or other years would follow the same or similar patterns. Originality/ Value We designed the survey questionnaire ourselves, specifically to assess the real influence of journals. We used peer-reviewed scores to judge the journal evaluation effect of impact factors with different citation time windows. The main purpose of this study was to help researchers better understand the role of impact factors with different citation time windows in journal evaluation. PMID:26295157

An Analysis of Peer-Reviewed Scores and Impact Factors with Different Citation Time Windows: A Case Study of 28 Ophthalmologic Journals.

PubMed

Liu, Xue-Li; Gai, Shuang-Shuang; Zhang, Shi-Le; Wang, Pu

2015-01-01

An important attribute of the traditional impact factor was the controversial 2-year citation window. So far, several scholars have proposed using different citation time windows for evaluating journals. However, there is no confirmation whether a longer citation time window would be better. How did the journal evaluation effects of 3IF, 4IF, and 6IF comparing with 2IF and 5IF? In order to understand these questions, we made a comparative study of impact factors with different citation time windows with the peer-reviewed scores of ophthalmologic journals indexed by Science Citation Index Expanded (SCIE) database. The peer-reviewed scores of 28 ophthalmologic journals were obtained through a self-designed survey questionnaire. Impact factors with different citation time windows (including 2IF, 3IF, 4IF, 5IF, and 6IF) of 28 ophthalmologic journals were computed and compared in accordance with each impact factor's definition and formula, using the citation analysis function of the Web of Science (WoS) database. An analysis of the correlation between impact factors with different citation time windows and peer-reviewed scores was carried out. Although impact factor values with different citation time windows were different, there was a high level of correlation between them when it came to evaluating journals. In the current study, for ophthalmologic journals' impact factors with different time windows in 2013, 3IF and 4IF seemed the ideal ranges for comparison, when assessed in relation to peer-reviewed scores. In addition, the 3-year and 4-year windows were quite consistent with the cited peak age of documents published by ophthalmologic journals. Our study is based on ophthalmology journals and we only analyze the impact factors with different citation time window in 2013, so it has yet to be ascertained whether other disciplines (especially those with a later cited peak) or other years would follow the same or similar patterns. We designed the survey questionnaire ourselves, specifically to assess the real influence of journals. We used peer-reviewed scores to judge the journal evaluation effect of impact factors with different citation time windows. The main purpose of this study was to help researchers better understand the role of impact factors with different citation time windows in journal evaluation.

ROCker: accurate detection and quantification of target genes in short-read metagenomic data sets by modeling sliding-window bitscores

DOE PAGES

Orellana, Luis H.; Rodriguez-R, Luis M.; Konstantinidis, Konstantinos T.

2016-10-07

Functional annotation of metagenomic and metatranscriptomic data sets relies on similarity searches based on e-value thresholds resulting in an unknown number of false positive and negative matches. To overcome these limitations, we introduce ROCker, aimed at identifying position-specific, most-discriminant thresholds in sliding windows along the sequence of a target protein, accounting for non-discriminative domains shared by unrelated proteins. ROCker employs the receiver operating characteristic (ROC) curve to minimize false discovery rate (FDR) and calculate the best thresholds based on how simulated shotgun metagenomic reads of known composition map onto well-curated reference protein sequences and thus, differs from HMM profiles andmore » related methods. We showcase ROCker using ammonia monooxygenase (amoA) and nitrous oxide reductase (nosZ) genes, mediating oxidation of ammonia and the reduction of the potent greenhouse gas, N 2O, to inert N 2, respectively. ROCker typically showed 60-fold lower FDR when compared to the common practice of using fixed e-values. Previously uncounted ‘atypical’ nosZ genes were found to be two times more abundant, on average, than their typical counterparts in most soil metagenomes and the abundance of bacterial amoA was quantified against the highly-related particulate methane monooxygenase (pmoA). Therefore, ROCker can reliably detect and quantify target genes in short-read metagenomes.« less

ROCker: accurate detection and quantification of target genes in short-read metagenomic data sets by modeling sliding-window bitscores

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orellana, Luis H.; Rodriguez-R, Luis M.; Konstantinidis, Konstantinos T.

Functional annotation of metagenomic and metatranscriptomic data sets relies on similarity searches based on e-value thresholds resulting in an unknown number of false positive and negative matches. To overcome these limitations, we introduce ROCker, aimed at identifying position-specific, most-discriminant thresholds in sliding windows along the sequence of a target protein, accounting for non-discriminative domains shared by unrelated proteins. ROCker employs the receiver operating characteristic (ROC) curve to minimize false discovery rate (FDR) and calculate the best thresholds based on how simulated shotgun metagenomic reads of known composition map onto well-curated reference protein sequences and thus, differs from HMM profiles andmore » related methods. We showcase ROCker using ammonia monooxygenase (amoA) and nitrous oxide reductase (nosZ) genes, mediating oxidation of ammonia and the reduction of the potent greenhouse gas, N 2O, to inert N 2, respectively. ROCker typically showed 60-fold lower FDR when compared to the common practice of using fixed e-values. Previously uncounted ‘atypical’ nosZ genes were found to be two times more abundant, on average, than their typical counterparts in most soil metagenomes and the abundance of bacterial amoA was quantified against the highly-related particulate methane monooxygenase (pmoA). Therefore, ROCker can reliably detect and quantify target genes in short-read metagenomes.« less

ROCker: accurate detection and quantification of target genes in short-read metagenomic data sets by modeling sliding-window bitscores

PubMed Central

2017-01-01

Abstract Functional annotation of metagenomic and metatranscriptomic data sets relies on similarity searches based on e-value thresholds resulting in an unknown number of false positive and negative matches. To overcome these limitations, we introduce ROCker, aimed at identifying position-specific, most-discriminant thresholds in sliding windows along the sequence of a target protein, accounting for non-discriminative domains shared by unrelated proteins. ROCker employs the receiver operating characteristic (ROC) curve to minimize false discovery rate (FDR) and calculate the best thresholds based on how simulated shotgun metagenomic reads of known composition map onto well-curated reference protein sequences and thus, differs from HMM profiles and related methods. We showcase ROCker using ammonia monooxygenase (amoA) and nitrous oxide reductase (nosZ) genes, mediating oxidation of ammonia and the reduction of the potent greenhouse gas, N2O, to inert N2, respectively. ROCker typically showed 60-fold lower FDR when compared to the common practice of using fixed e-values. Previously uncounted ‘atypical’ nosZ genes were found to be two times more abundant, on average, than their typical counterparts in most soil metagenomes and the abundance of bacterial amoA was quantified against the highly-related particulate methane monooxygenase (pmoA). Therefore, ROCker can reliably detect and quantify target genes in short-read metagenomes. PMID:28180325

Predicting progression of mild cognitive impairment to dementia using neuropsychological data: a supervised learning approach using time windows.

PubMed

Pereira, Telma; Lemos, Luís; Cardoso, Sandra; Silva, Dina; Rodrigues, Ana; Santana, Isabel; de Mendonça, Alexandre; Guerreiro, Manuela; Madeira, Sara C

2017-07-19

Predicting progression from a stage of Mild Cognitive Impairment to dementia is a major pursuit in current research. It is broadly accepted that cognition declines with a continuum between MCI and dementia. As such, cohorts of MCI patients are usually heterogeneous, containing patients at different stages of the neurodegenerative process. This hampers the prognostic task. Nevertheless, when learning prognostic models, most studies use the entire cohort of MCI patients regardless of their disease stages. In this paper, we propose a Time Windows approach to predict conversion to dementia, learning with patients stratified using time windows, thus fine-tuning the prognosis regarding the time to conversion. In the proposed Time Windows approach, we grouped patients based on the clinical information of whether they converted (converter MCI) or remained MCI (stable MCI) within a specific time window. We tested time windows of 2, 3, 4 and 5 years. We developed a prognostic model for each time window using clinical and neuropsychological data and compared this approach with the commonly used in the literature, where all patients are used to learn the models, named as First Last approach. This enables to move from the traditional question "Will a MCI patient convert to dementia somewhere in the future" to the question "Will a MCI patient convert to dementia in a specific time window". The proposed Time Windows approach outperformed the First Last approach. The results showed that we can predict conversion to dementia as early as 5 years before the event with an AUC of 0.88 in the cross-validation set and 0.76 in an independent validation set. Prognostic models using time windows have higher performance when predicting progression from MCI to dementia, when compared to the prognostic approach commonly used in the literature. Furthermore, the proposed Time Windows approach is more relevant from a clinical point of view, predicting conversion within a temporal interval rather than sometime in the future and allowing clinicians to timely adjust treatments and clinical appointments.

Exploiting visual search theory to infer social interactions

NASA Astrophysics Data System (ADS)

Rota, Paolo; Dang-Nguyen, Duc-Tien; Conci, Nicola; Sebe, Nicu

2013-03-01

In this paper we propose a new method to infer human social interactions using typical techniques adopted in literature for visual search and information retrieval. The main piece of information we use to discriminate among different types of interactions is provided by proxemics cues acquired by a tracker, and used to distinguish between intentional and casual interactions. The proxemics information has been acquired through the analysis of two different metrics: on the one hand we observe the current distance between subjects, and on the other hand we measure the O-space synergy between subjects. The obtained values are taken at every time step over a temporal sliding window, and processed in the Discrete Fourier Transform (DFT) domain. The features are eventually merged into an unique array, and clustered using the K-means algorithm. The clusters are reorganized using a second larger temporal window into a Bag Of Words framework, so as to build the feature vector that will feed the SVM classifier.

Detail, juncture bay of 1917 and 1942 construction, showing construction ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Detail, juncture bay of 1917 and 1942 construction, showing construction bay and typical windows, center of south elevation. - Watertown Arsenal, Building No. 311, Arsenal Street, Watertown, Middlesex County, MA

Investigating crater lake warming using ASTER thermal imagery: Case studies at Ruapehu, Poás, Kawah Ijen, and Copahué Volcanoes

NASA Astrophysics Data System (ADS)

Trunk, Laura; Bernard, Alain

2008-12-01

A two-channel or split-window algorithm designed to correct for atmospheric conditions was applied to thermal images taken by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) of Lake Yugama on Kusatsu-Shirane volcano in Japan in order to measure the temperature of its crater lake. These temperature calculations were validated using lake water temperatures that were collected on the ground. Overall, the agreement between the temperatures calculated using the split-window method and ground truth is quite good, typically ± 1.5 °C for cloud-free images. Data from fieldwork undertaken in the summer of 2004 at Kusatsu-Shirane allow a comparison of ground-truth data with the radiant temperatures measured using ASTER imagery. Further images were analyzed of Ruapehu, Poás, Kawah Ijen, and Copahué volcanoes to acquire time-series of lake temperatures. A total of 64 images of these 4 volcanoes covering a wide range of geographical locations and climates were analyzed. Results of the split-window algorithm applied to ASTER images are reliable for monitoring thermal changes in active volcanic lakes. These temperature data, when considered in conjunction with traditional volcano monitoring techniques, lead to a better understanding of whether and how thermal changes in crater lakes aid in eruption forecasting.

Quivering on the brink: Common observations of turbidity current frequency and triggering in disparate settings

NASA Astrophysics Data System (ADS)

Clare, M. A.; Rosenberger, K. J.; Parsons, D. R.; Gales, J. A.; Gwiazda, R.; Paull, C. K.; Talling, P.; Cartigny, M.; Azpiroz, M.; Pope, E.; Hizzett, J. L.; Hughes Clarke, J. E.

2017-12-01

Turbidity currents pose a hazard to seafloor infrastructure, convey sediment to the deep sea, and provide nutrients to benthic communities. Despite their importance, we still know little about specifically how and when such powerful long run-out flows are triggered, and how strongly different trigger mechanisms control flow behaviour. New advances in direct monitoring now allow us to precisely constrain turbidity current frequency and test the efficiency of previously hypothesised triggering mechanisms. Here, we document the timing of sub-annual turbidity currents based on direct measurements using Acoustic Doppler Current Profilers at four different sites. Two sites are located at offshore fjord-head deltas in British Columbia (Squamish delta & Bute Inlet), which are fed by meltwater in spring and summer. The third is the deep-water Congo Canyon, which is located offshore Angola, and is fed by the second largest river in the world. Fourth is the Monterey Canyon, offshore California, which does not have a direct link to a river and is instead fed by littoral drift. Despite the differences in scale and setting, all of the sites show similar trends in turbidity current frequency. The first commonality is that flow timing is typically delayed (hours to weeks) following periods of rapid sediment discharge, rather than immediately coincident with them. The second commonality is that flows are rare (typically they do not occur at all) for at least half of the year in each of the sites. Instead, flows are clustered within a specific time window. We underline the importance of preconditioning prior to, and during that time window and propose that an environmental threshold must be exceeded in order to "switch on" these systems. This threshold primarily relates to magnitude of sediment delivery at the head of the channel or canyon. Once that threshold is surpassed, then systems are primed for action, quivering on the brink, allowing even small external perturbations to trigger flows.

A new adaptive multiple modelling approach for non-linear and non-stationary systems

NASA Astrophysics Data System (ADS)

Chen, Hao; Gong, Yu; Hong, Xia

2016-07-01

This paper proposes a novel adaptive multiple modelling algorithm for non-linear and non-stationary systems. This simple modelling paradigm comprises K candidate sub-models which are all linear. With data available in an online fashion, the performance of all candidate sub-models are monitored based on the most recent data window, and M best sub-models are selected from the K candidates. The weight coefficients of the selected sub-model are adapted via the recursive least square (RLS) algorithm, while the coefficients of the remaining sub-models are unchanged. These M model predictions are then optimally combined to produce the multi-model output. We propose to minimise the mean square error based on a recent data window, and apply the sum to one constraint to the combination parameters, leading to a closed-form solution, so that maximal computational efficiency can be achieved. In addition, at each time step, the model prediction is chosen from either the resultant multiple model or the best sub-model, whichever is the best. Simulation results are given in comparison with some typical alternatives, including the linear RLS algorithm and a number of online non-linear approaches, in terms of modelling performance and time consumption.

Optimal Design for Hetero-Associative Memory: Hippocampal CA1 Phase Response Curve and Spike-Timing-Dependent Plasticity

PubMed Central

Miyata, Ryota; Ota, Keisuke; Aonishi, Toru

2013-01-01

Recently reported experimental findings suggest that the hippocampal CA1 network stores spatio-temporal spike patterns and retrieves temporally reversed and spread-out patterns. In this paper, we explore the idea that the properties of the neural interactions and the synaptic plasticity rule in the CA1 network enable it to function as a hetero-associative memory recalling such reversed and spread-out spike patterns. In line with Lengyel’s speculation (Lengyel et al., 2005), we firstly derive optimally designed spike-timing-dependent plasticity (STDP) rules that are matched to neural interactions formalized in terms of phase response curves (PRCs) for performing the hetero-associative memory function. By maximizing object functions formulated in terms of mutual information for evaluating memory retrieval performance, we search for STDP window functions that are optimal for retrieval of normal and doubly spread-out patterns under the constraint that the PRCs are those of CA1 pyramidal neurons. The system, which can retrieve normal and doubly spread-out patterns, can also retrieve reversed patterns with the same quality. Finally, we demonstrate that purposely designed STDP window functions qualitatively conform to typical ones found in CA1 pyramidal neurons. PMID:24204822

Possible disruption of remote viewing by complex weak magnetic fields around the stimulus site and the possibility of accessing real phase space: a pilot study.

PubMed

Koren, S A; Persinger, M A

2002-12-01

In 2002 Persinger, Roll, Tiller, Koren, and Cook considered whether there are physical processes by which recondite information exists within the space and time of objects or events. The stimuli that compose this information might be directly detected within the whole brain without being processed by the typical sensory modalities. We tested the artist Ingo Swann who can reliably draw and describe randomly selected photographs sealed in envelopes in another room. In the present experiment the photographs were immersed continuously in repeated presentations (5 times per sec.) of one of two types of computer-generated complex magnetic field patterns whose intensities were less than 20 nT over most of the area. WINDOWS-generated but not DOS-generated patterns were associated with a marked decrease in Mr. Swann's accuracy. Whereas the DOS software generated exactly the same pattern, WINDOWS software phase-modulated the actual wave form resulting in an infinite bandwidth and complexity. We suggest that information obtained by processes attributed to "paranormal" phenomena have physical correlates that can be masked by weak, infinitely variable magnetic fields.

Sitting in the Pilot's Seat; Optimizing Human-Systems Interfaces for Unmanned Aerial Vehicles

NASA Technical Reports Server (NTRS)

Queen, Steven M.; Sanner, Kurt Gregory

2011-01-01

One of the pilot-machine interfaces (the forward viewing camera display) for an Unmanned Aerial Vehicle called the DROID (Dryden Remotely Operated Integrated Drone) will be analyzed for optimization. The goal is to create a visual display for the pilot that as closely resembles an out-the-window view as possible. There are currently no standard guidelines for designing pilot-machine interfaces for UAVs. Typically, UAV camera views have a narrow field, which limits the situational awareness (SA) of the pilot. Also, at this time, pilot-UAV interfaces often use displays that have a diagonal length of around 20". Using a small display may result in a distorted and disproportional view for UAV pilots. Making use of a larger display and a camera lens with a wider field of view may minimize the occurrences of pilot error associated with the inability to see "out the window" as in a manned airplane. It is predicted that the pilot will have a less distorted view of the DROID s surroundings, quicker response times and more stable vehicle control. If the experimental results validate this concept, other UAV pilot-machine interfaces will be improved with this design methodology.

6. Historic American Buildings Survey Alex Bush, Photographer, October 16, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. Historic American Buildings Survey Alex Bush, Photographer, October 16, 1935 CLOSE-UP OF EXTERIOR VIEW OF TYPICAL PORTICO WINDOW - University of Alabama, President's House, University Boulevard, Tuscaloosa, Tuscaloosa County, AL

Low-Emissivity, Energy-Control, Retrofit Window Film: Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Winckler, Lisa

Solutia Performance Films, utilizing funding from the U.S. Department of Energy's Buildings Technologies Program, completed research to develop, validate, and commercialize a range of cost-effective, low-emissivity energy-control retrofit window films with significantly improved emissivity over current technology. These films, sold under the EnerLogic® trade name, offer the energy-saving properties of modern low-e windows, with several advantages over replacement windows, such as: lower initial installation cost, a significantly lower product carbon footprint, and an ability to provide a much faster return on investment. EnerLogic® window films also offer significantly greater energy savings than previously available with window films with similar visiblemore » light transmissions. EnerLogic® window films offer these energy-saving advantages over other window films due to its ability to offer both summer cooling and winter heating savings. Unlike most window films, that produce savings only during the cooling season, EnerLogic® window film is an all-season, low-emissivity (low-e) film that produces both cooling and heating season savings. This paper will present technical information on the development hurdles as well as details regarding the following claims being made about EnerLogic® window film, which can be found at www.EnerLogicfilm.com: 1. Other window film technologies save energy. EnerLogic® window film's patent-pending coating delivers excellent energy efficiency in every season, so no other film can match its annual dollar or energy consumption savings. 2. EnerLogic® window film is a low-cost, high-return technology that compares favorably to other popular energy-saving measures both in terms of energy efficiency and cost savings. In fact, EnerLogic® window film typically outperforms most of the alternatives in terms of simple payback. 3. EnerLogic® window film provides unparalleled glass insulating capabilities for window film products. With its patent-pending low-e technology, EnerLogic® window film has the best insulating performance of any film product available. The insulating power of EnerLogic® window film gives single-pane windows the annual insulating performance of double-pane windows - and gives double-pane windows the annual insulating performance of triple-pane windows.« less

NOTE: The feasibility of an infrared system for real-time visualization and mapping of ultrasound fields

NASA Astrophysics Data System (ADS)

Shaw, Adam; Nunn, John

2010-06-01

In treatment planning for ultrasound therapy, it is desirable to know the 3D structure of the ultrasound field. However, mapping an ultrasound field in 3D is very slow, with even a single planar raster scan taking typically several hours. Additionally, hydrophones that are used for field mapping are expensive and can be damaged in some therapy fields. So there is value in rapid methods which enable visualization and mapping of the ultrasound field in about 1 min. In this note we explore the feasibility of mapping the intensity distribution by measuring the temperature distribution produced in a thin sheet of absorbing material. A 0.2 mm thick acetate sheet forms a window in the wall of a water tank containing the transducer. The window is oriented at 45° to the beam axis, and the distance from the transducer to the window can be varied. The temperature distribution is measured with an infrared camera; thermal images of the inclined plane could be viewed in real time or images could be captured for later analysis and 3D field reconstruction. We conclude that infrared thermography can be used to gain qualitative information about ultrasound fields. Thermal images are easily visualized with good spatial and thermal resolutions (0.044 mm and 0.05 °C in our system). The focus and field structure such as side lobes can be identified in real time from the direct video output. 3D maps and image planes at arbitrary orientations to the beam axis can be obtained and reconstructed within a few minutes. In this note we are primarily interested in the technique for characterization of high intensity focused ultrasound (HIFU) fields, but other applications such as physiotherapy fields are also possible.

The feasibility of an infrared system for real-time visualization and mapping of ultrasound fields.

PubMed

Shaw, Adam; Nunn, John

2010-06-07

In treatment planning for ultrasound therapy, it is desirable to know the 3D structure of the ultrasound field. However, mapping an ultrasound field in 3D is very slow, with even a single planar raster scan taking typically several hours. Additionally, hydrophones that are used for field mapping are expensive and can be damaged in some therapy fields. So there is value in rapid methods which enable visualization and mapping of the ultrasound field in about 1 min. In this note we explore the feasibility of mapping the intensity distribution by measuring the temperature distribution produced in a thin sheet of absorbing material. A 0.2 mm thick acetate sheet forms a window in the wall of a water tank containing the transducer. The window is oriented at 45 degrees to the beam axis, and the distance from the transducer to the window can be varied. The temperature distribution is measured with an infrared camera; thermal images of the inclined plane could be viewed in real time or images could be captured for later analysis and 3D field reconstruction. We conclude that infrared thermography can be used to gain qualitative information about ultrasound fields. Thermal images are easily visualized with good spatial and thermal resolutions (0.044 mm and 0.05 degrees C in our system). The focus and field structure such as side lobes can be identified in real time from the direct video output. 3D maps and image planes at arbitrary orientations to the beam axis can be obtained and reconstructed within a few minutes. In this note we are primarily interested in the technique for characterization of high intensity focused ultrasound (HIFU) fields, but other applications such as physiotherapy fields are also possible.

Mitigating reentry radio blackout by using a traveling magnetic field

NASA Astrophysics Data System (ADS)

Zhou, Hui; Li, Xiaoping; Xie, Kai; Liu, Yanming; Yu, Yuanyuan

2017-10-01

A hypersonic flight or a reentry vehicle is surrounded by a plasma layer that prevents electromagnetic wave transmission, which results in radio blackout. The magnetic-window method is considered a promising means to mitigate reentry communication blackout. However, the real application of this method is limited because of the need for strong magnetic fields. To reduce the required magnetic field strength, a novel method that applies a traveling magnetic field (TMF) is proposed in this study. A mathematical model based on magneto-hydrodynamic theory is adopted to analyze the effect of TMF on plasma. The mitigating effects of the TMF on the blackout of typical frequency bands, including L-, S-, and C-bands, are demonstrated. Results indicate that a significant reduction of plasma density occurs in the magnetic-window region by applying a TMF, and the reduction ratio is positively correlated with the velocity of the TMF. The required traveling velocities for eliminating the blackout of the Global Positioning System (GPS) and the typical telemetry system are also discussed. Compared with the constant magnetic-window method, the TMF method needs lower magnetic field strength and is easier to realize in the engineering field.

Training loads and injury risk in Australian football-differing acute: chronic workload ratios influence match injury risk.

PubMed

Carey, David L; Blanch, Peter; Ong, Kok-Leong; Crossley, Kay M; Crow, Justin; Morris, Meg E

2017-08-01

(1) To investigate whether a daily acute:chronic workload ratio informs injury risk in Australian football players; (2) to identify which combination of workload variable, acute and chronic time window best explains injury likelihood. Workload and injury data were collected from 53 athletes over 2 seasons in a professional Australian football club. Acute:chronic workload ratios were calculated daily for each athlete, and modelled against non-contact injury likelihood using a quadratic relationship. 6 workload variables, 8 acute time windows (2-9 days) and 7 chronic time windows (14-35 days) were considered (336 combinations). Each parameter combination was compared for injury likelihood fit (using R 2 ). The ratio of moderate speed running workload (18-24 km/h) in the previous 3 days (acute time window) compared with the previous 21 days (chronic time window) best explained the injury likelihood in matches (R 2 =0.79) and in the immediate 2 or 5 days following matches (R 2 =0.76-0.82). The 3:21 acute:chronic workload ratio discriminated between high-risk and low-risk athletes (relative risk=1.98-2.43). Using the previous 6 days to calculate the acute workload time window yielded similar results. The choice of acute time window significantly influenced model performance and appeared to reflect the competition and training schedule. Daily workload ratios can inform injury risk in Australian football. Clinicians and conditioning coaches should consider the sport-specific schedule of competition and training when choosing acute and chronic time windows. For Australian football, the ratio of moderate speed running in a 3-day or 6-day acute time window and a 21-day chronic time window best explained injury risk. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Training loads and injury risk in Australian football—differing acute: chronic workload ratios influence match injury risk

PubMed Central

Carey, David L; Blanch, Peter; Ong, Kok-Leong; Crossley, Kay M; Crow, Justin; Morris, Meg E

2017-01-01

Aims (1) To investigate whether a daily acute:chronic workload ratio informs injury risk in Australian football players; (2) to identify which combination of workload variable, acute and chronic time window best explains injury likelihood. Methods Workload and injury data were collected from 53 athletes over 2 seasons in a professional Australian football club. Acute:chronic workload ratios were calculated daily for each athlete, and modelled against non-contact injury likelihood using a quadratic relationship. 6 workload variables, 8 acute time windows (2–9 days) and 7 chronic time windows (14–35 days) were considered (336 combinations). Each parameter combination was compared for injury likelihood fit (using R2). Results The ratio of moderate speed running workload (18–24 km/h) in the previous 3 days (acute time window) compared with the previous 21 days (chronic time window) best explained the injury likelihood in matches (R2=0.79) and in the immediate 2 or 5 days following matches (R2=0.76–0.82). The 3:21 acute:chronic workload ratio discriminated between high-risk and low-risk athletes (relative risk=1.98–2.43). Using the previous 6 days to calculate the acute workload time window yielded similar results. The choice of acute time window significantly influenced model performance and appeared to reflect the competition and training schedule. Conclusions Daily workload ratios can inform injury risk in Australian football. Clinicians and conditioning coaches should consider the sport-specific schedule of competition and training when choosing acute and chronic time windows. For Australian football, the ratio of moderate speed running in a 3-day or 6-day acute time window and a 21-day chronic time window best explained injury risk. PMID:27789430

Time-marching multi-grid seismic tomography

NASA Astrophysics Data System (ADS)

Tong, P.; Yang, D.; Liu, Q.

2016-12-01

From the classic ray-based traveltime tomography to the state-of-the-art full waveform inversion, because of the nonlinearity of seismic inverse problems, a good starting model is essential for preventing the convergence of the objective function toward local minima. With a focus on building high-accuracy starting models, we propose the so-called time-marching multi-grid seismic tomography method in this study. The new seismic tomography scheme consists of a temporal time-marching approach and a spatial multi-grid strategy. We first divide the recording period of seismic data into a series of time windows. Sequentially, the subsurface properties in each time window are iteratively updated starting from the final model of the previous time window. There are at least two advantages of the time-marching approach: (1) the information included in the seismic data of previous time windows has been explored to build the starting models of later time windows; (2) seismic data of later time windows could provide extra information to refine the subsurface images. Within each time window, we use a multi-grid method to decompose the scale of the inverse problem. Specifically, the unknowns of the inverse problem are sampled on a coarse mesh to capture the macro-scale structure of the subsurface at the beginning. Because of the low dimensionality, it is much easier to reach the global minimum on a coarse mesh. After that, finer meshes are introduced to recover the micro-scale properties. That is to say, the subsurface model is iteratively updated on multi-grid in every time window. We expect that high-accuracy starting models should be generated for the second and later time windows. We will test this time-marching multi-grid method by using our newly developed eikonal-based traveltime tomography software package tomoQuake. Real application results in the 2016 Kumamoto earthquake (Mw 7.0) region in Japan will be demonstrated.

Bias Reduction in Short Records of Satellite Soil Moisture

NASA Technical Reports Server (NTRS)

Reichle, Rolf H.; Koster, Randal D.

2004-01-01

Although surface soil moisture data from different sources (satellite retrievals, ground measurements, and land model integrations of observed meteorological forcing data) have been shown to contain consistent and useful information in their seasonal cycle and anomaly signals, they typically exhibit very different mean values and variability. These biases pose a severe obstacle to exploiting the useful information contained in satellite retrievals through data assimilation. A simple method of bias removal is to match the cumulative distribution functions (cdf) of the satellite and model data. However, accurate cdf estimation typically requires a long record of satellite data. We demonstrate here that by wing spatial sampling with a 2 degree moving window we can obtain local statistics based on a one-year satellite record that are a good approximation to those that would be derived from a much longer time series. This result should increase the usefulness of relatively short satellite data records.

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 have very stable gain behavior over > 7 C cm2 of charge extracted. They are high temperature compatible and have minimal outgassing, which shortens and simplifies the sealed tube production process and should improve overall lifetimes. Bialkali (NaKSb) semitransparent photocathodes with > 20% quantum efficiency have also been made on 20 cm borosilicate windows compatible with the window seals for the large sealed tube device. The photocathodes have good response uniformity and have been stable for > 5 months in testing. Tests with a 20 cm detector with a cross delay line readout have achieved ~50µm FWHM imaging with single photon sub-ns timing and MHz event rates, and tests with a 10 x 10cm detector with cross strip readout has achieved ~20µm FWHM imaging with >4 MHz event rates with ~10% deadtime. We will discuss the details and implications of these novel detector implementations and their potential applications.

Statistical baseline assessment in cardiotocography.

PubMed

Agostinelli, Angela; Braccili, Eleonora; Marchegiani, Enrico; Rosati, Riccardo; Sbrollini, Agnese; Burattini, Luca; Morettini, Micaela; Di Nardo, Francesco; Fioretti, Sandro; Burattini, Laura

2017-07-01

Cardiotocography (CTG) is the most common non-invasive diagnostic technique to evaluate fetal well-being. It consists in the recording of fetal heart rate (FHR; bpm) and maternal uterine contractions. Among the main parameters characterizing FHR, baseline (BL) is fundamental to determine fetal hypoxia and distress. In computerized applications, BL is typically computed as mean FHR±ΔFHR, with ΔFHR=8 bpm or ΔFHR=10 bpm, both values being experimentally fixed. In this context, the present work aims: to propose a statistical procedure for ΔFHR assessment; to quantitatively determine ΔFHR value by applying such procedure to clinical data; and to compare the statistically-determined ΔFHR value against the experimentally-determined ΔFHR values. To these aims, the 552 recordings of the "CTU-UHB intrapartum CTG database" from Physionet were submitted to an automatic procedure, which consisted in a FHR preprocessing phase and a statistical BL assessment. During preprocessing, FHR time series were divided into 20-min sliding windows, in which missing data were removed by linear interpolation. Only windows with a correction rate lower than 10% were further processed for BL assessment, according to which ΔFHR was computed as FHR standard deviation. Total number of accepted windows was 1192 (38.5%) over 383 recordings (69.4%) with at least an accepted window. Statistically-determined ΔFHR value was 9.7 bpm. Such value was statistically different from 8 bpm (P<;10 -19 ) but not from 10 bpm (P=0.16). Thus, ΔFHR=10 bpm is preferable over 8 bpm because both experimentally and statistically validated.

Valuing the health benefits of improving indoor air quality in residences.

PubMed

Chau, C K; Hui, W K; Tse, M S

2008-05-01

Unlike commercial premises, the indoor air quality of residences is more dynamic, uncontrolled, and prone to human behavioral changes. In consequence, measuring the health benefit gains derived from improving indoor air quality in residences is more complicated. To overcome this, a human thermal comfort model was first integrated with indoor microenvironment models, and subsequently linked with appropriate concentration-response and economic data for estimating the economic benefit gains derived from improving indoor air quality in residences for an adult and an elderly person. In this study, the development of the model is illustrated by using a typical residential apartment locating at the worst air quality neighborhood in Hong Kong and the daily weather profiles between 2002 and 2006. Three types of personal intervention measures were examined in the study: (i) using air cleaner in residence, (ii) changing time spent in residence, and (iii) relocating to a better air quality neighborhood. Our results revealed that employing air cleaners with windows closed in residence throughout the entire year was the most beneficial measure as it could provide the greatest annual health benefit gains. It would give a maximum of HK$2072 in 5-year cumulative benefit gain for an adult and HK$1700 for an elderly person. Employing air cleaners with windows closed in only cool season (October through March) could give the highest marginal return per dollar spent. The benefit gains would become smaller when windows were opened to a greater extent. By contrast, relocating to a better air quality neighborhood and changing the time spent in residence did not appeal to be beneficial intervention measures.

Computing an optimal time window of audiovisual integration in focused attention tasks: illustrated by studies on effect of age and prior knowledge.

PubMed

Colonius, Hans; Diederich, Adele

2011-07-01

The concept of a "time window of integration" holds that information from different sensory modalities must not be perceived too far apart in time in order to be integrated into a multisensory perceptual event. Empirical estimates of window width differ widely, however, ranging from 40 to 600 ms depending on context and experimental paradigm. Searching for theoretical derivation of window width, Colonius and Diederich (Front Integr Neurosci 2010) developed a decision-theoretic framework using a decision rule that is based on the prior probability of a common source, the likelihood of temporal disparities between the unimodal signals, and the payoff for making right or wrong decisions. Here, this framework is extended to the focused attention task where subjects are asked to respond to signals from a target modality only. Evoking the framework of the time-window-of-integration (TWIN) model, an explicit expression for optimal window width is obtained. The approach is probed on two published focused attention studies. The first is a saccadic reaction time study assessing the efficiency with which multisensory integration varies as a function of aging. Although the window widths for young and older adults differ by nearly 200 ms, presumably due to their different peripheral processing speeds, neither of them deviates significantly from the optimal values. In the second study, head saccadic reactions times to a perfectly aligned audiovisual stimulus pair had been shown to depend on the prior probability of spatial alignment. Intriguingly, they reflected the magnitude of the time-window widths predicted by our decision-theoretic framework, i.e., a larger time window is associated with a higher prior probability.

Effect of partial covering of the visitor viewing area window on positioning and orientation of zoo orangutans: A preference test.

PubMed

Bloomfield, Rachel C; Gillespie, Graeme R; Kerswell, Keven J; Butler, Kym L; Hemsworth, Paul H

2015-01-01

The window of the visitor viewing area adjacent to an animal platform in an orangutan enclosure was altered to produce three viewing treatments in a randomized controlled experiment. These treatments were window uncovered, left side of the window covered or right side of the window covered. Observations were conducted on the orangutans present on the platform, and on their location (left or right side), and orientation (towards or away from the window) while on the platform. The partial covering of the window had little effect on the proportion of time orangutans spent on the viewing platform, or on the direction they faced when on the platform. When the orangutans were facing towards the window, and the right side was uncovered, irrespective of whether the left side was covered, they spent about three quarters of the time on the right side, suggesting a preference for the right side of the platform. However, when the right side was covered and the left side uncovered, the animals facing towards the window spent only about a quarter of the time on the right side, that is, they spent more time on the uncovered side. The results suggest that the orangutans have a preference to position themselves to face the window of the visitor viewing area. © 2015 Wiley Periodicals, Inc.

Microwave window breakdown experiments and simulations on the UM/L-3 relativistic magnetron

NASA Astrophysics Data System (ADS)

Hoff, B. W.; Mardahl, P. J.; Gilgenbach, R. M.; Haworth, M. D.; French, D. M.; Lau, Y. Y.; Franzi, M.

2009-09-01

Experiments have been performed on the UM/L-3 (6-vane, L-band) relativistic magnetron to test a new microwave window configuration designed to limit vacuum side breakdown. In the baseline case, acrylic microwave windows were mounted between three of the waveguide coupling cavities in the anode block vacuum housing and the output waveguides. Each of the six 3 cm deep coupling cavities is separated from its corresponding anode cavity by a 1.75 cm wide aperture. In the baseline case, vacuum side window breakdown was observed to initiate at single waveguide output powers close to 20 MW. In the new window configuration, three Air Force Research Laboratory-designed, vacuum-rated directional coupler waveguide segments were mounted between the coupling cavities and the microwave windows. The inclusion of the vacuum side power couplers moved the microwave windows an additional 30 cm away from the anode apertures. Additionally, the Lucite microwave windows were replaced with polycarbonate windows and the microwave window mounts were redesigned to better maintain waveguide continuity in the region around the microwave windows. No vacuum side window breakdown was observed in the new window configuration at single waveguide output powers of 120+MW (a factor of 3 increase in measured microwave pulse duration and factor of 3 increase in measured peak power over the baseline case). Simulations were performed to investigate likely causes for the window breakdown in the original configuration. Results from these simulations have shown that in the original configuration, at typical operating voltage and magnetic field ranges, electrons emitted from the anode block microwave apertures strike the windows with a mean kinetic energy of 33 keV with a standard deviation of 14 keV. Calculations performed using electron impact angle and energy data predict a first generation secondary electron yield of 65% of the primary electron population. The effects of the primary aperture electron impacts, combined with multiplication of the secondary populations, were determined to be the likely causes of the poor microwave window performance in the original configuration.

Real-time operating system timing jitter and its impact on motor control

NASA Astrophysics Data System (ADS)

Proctor, Frederick M.; Shackleford, William P.

2001-12-01

General-purpose microprocessors are increasingly being used for control applications due to their widespread availability and software support for non-control functions like networking and operator interfaces. Two classes of real-time operating systems (RTOS) exist for these systems. The traditional RTOS serves as the sole operating system, and provides all OS services. Examples include ETS, LynxOS, QNX, Windows CE and VxWorks. RTOS extensions add real-time scheduling capabilities to non-real-time OSes, and provide minimal services needed for the time-critical portions of an application. Examples include RTAI and RTL for Linux, and HyperKernel, OnTime and RTX for Windows NT. Timing jitter is an issue in these systems, due to hardware effects such as bus locking, caches and pipelines, and software effects from mutual exclusion resource locks, non-preemtible critical sections, disabled interrupts, and multiple code paths in the scheduler. Jitter is typically on the order of a microsecond to a few tens of microseconds for hard real-time operating systems, and ranges from milliseconds to seconds in the worst case for soft real-time operating systems. The question of its significance on the performance of a controller arises. Naturally, the smaller the scheduling period required for a control task, the more significant is the impact of timing jitter. Aside from this intuitive relationship is the greater significance of timing on open-loop control, such as for stepper motors, than for closed-loop control, such as for servo motors. Techniques for measuring timing jitter are discussed, and comparisons between various platforms are presented. Techniques to reduce jitter or mitigate its effects are presented. The impact of jitter on stepper motor control is analyzed.

4. Detail of the south side of the building showing ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. Detail of the south side of the building showing the decorative-brick cornice, typical double-hung window, and chimneys. Credit GADA/MRM. - Stroud Building, 31-33 North Central Avenue, Phoenix, Maricopa County, AZ

1. Exterior oblique view of north and east sides showing ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. Exterior oblique view of north and east sides showing entrance and typical window - Fort Hood, World War II Temporary Buildings, Dispatcher House, North of Park Avenue at Forty-ninth Street, Killeen, Bell County, TX

Remembering the Important Things: Semantic Importance in Stream Reasoning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, Rui; Greaves, Mark T.; Smith, William P.

Reasoning and querying over data streams rely on the abil- ity to deliver a sequence of stream snapshots to the processing algo- rithms. These snapshots are typically provided using windows as views into streams and associated window management strategies. Generally, the goal of any window management strategy is to preserve the most im- portant data in the current window and preferentially evict the rest, so that the retained data can continue to be exploited. A simple timestamp- based strategy is rst-in-rst-out (FIFO), in which items are replaced in strict order of arrival. All timestamp-based strategies implicitly assume that a temporalmore » ordering reliably re ects importance to the processing task at hand, and thus that window management using timestamps will maximize the ability of the processing algorithms to deliver accurate interpretations of the stream. In this work, we explore a general no- tion of semantic importance that can be used for window management for streams of RDF data using semantically-aware processing algorithms like deduction or semantic query. Semantic importance exploits the infor- mation carried in RDF and surrounding ontologies for ranking window data in terms of its likely contribution to the processing algorithms. We explore the general semantic categories of query contribution, prove- nance, and trustworthiness, as well as the contribution of domain-specic ontologies. We describe how these categories behave using several con- crete examples. Finally, we consider how a stream window management strategy based on semantic importance could improve overall processing performance, especially as available window sizes decrease.« less

Round window closure affects cochlear responses to suprathreshold stimuli.

PubMed

Cai, Qunfeng; Whitcomb, Carolyn; Eggleston, Jessica; Sun, Wei; Salvi, Richard; Hu, Bo Hua

2013-12-01

The round window acts as a vent for releasing inner ear pressure and facilitating basilar membrane vibration. Loss of this venting function affects cochlear function, which leads to hearing impairment. In an effort to identify functional changes that might be used in clinical diagnosis of round window atresia, the current investigation was designed to examine how the cochlea responds to suprathreshold stimuli following round window closure. Prospective, controlled, animal study. A rat model of round window occlusion (RWO) was established. With this model, the thresholds of auditory brainstem responses (ABR) and the input/output (IO) functions of distortion product otoacoustic emissions (DPOAEs) and acoustic startle responses were examined. Round window closure caused a mild shift in the thresholds of the auditory brainstem response (13.5 ± 9.1 dB). It also reduced the amplitudes of the distortion product otoacoustic emissions and the slope of the input/output functions. This peripheral change was accompanied by a significant reduction in the amplitude, but not the threshold, of the acoustic startle reflex, a motor response to suprathreshold sounds. In addition to causing mild increase in the threshold of the auditory brainstem response, round window occlusion reduced the slopes of both distortion product otoacoustic emissions and startle reflex input/output functions. These changes differ from those observed for typical conductive or sensory hearing loss, and could be present in patients with round window atresia. However, future clinical observations in patients are needed to confirm these findings. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

Modifications to a Laboratory-Scale Confined Laser Ignition Chamber for Pressure Measurements to 70 MPa

DTIC Science & Technology

2017-09-01

which is then turned over and pressed by hand against a flat surface. The solder ring is removed from the flange using a flat blade mini screwdriver...densities of M10 propellant. This series of experiments was conducted to get an indication of how many experiments could be run with the same window...While we were able to run 6 experiments with a pair of solder rings as the window seat, we typically replace the seat after 4 experiments have been

Summary of typical parameters that affect sound transmission through general aviation aircraft structures

NASA Technical Reports Server (NTRS)

Grosveld, F.; Navaneethan, R.; Roskam, J.

1981-01-01

This paper presents results of a systematic experimental investigation of parameters which affect sound transmission through general aviation structures. Parameters studied include angle of sound incidence, panel curvature, panel stresses, and edge conditions for bare panels; pane thickness, spacing, inclination of window panes, and depressurization for dual pane windows; densities of hard foam and sound absorption materials, air gaps, and trim panel thickness for multilayered panels. Based on the study, some promising methods for reducing interior noise in general aviation airplanes are discussed.

Monolithic control components for high power mm-waves

NASA Astrophysics Data System (ADS)

Armstrong, A.; Goodrich, J.; Moroney, W.; Wheeler, D.

1985-09-01

Monolithic PIN diode arrays are shown to provide significant advances in switching ratios, bandwidth, and high-power capability for millimeter control applications The PIN diodes are arranged in a series/parallel configuration and form an electronically controlled window for switching RF power by applying DC voltage. At Ka band, an SPST switch using the window array (WINAR) design typically has 0.6 dB insertion loss and 22 dB isolation over the 26.5 to 40.0 GHz band. The switch has over 500 W peak power and 25 W average power capability.

Experience with ActiveX control for simple channel access

DOE Office of Scientific and Technical Information (OSTI.GOV)

Timossi, C.; Nishimura, H.; McDonald, J.

2003-05-15

Accelerator control system applications at Berkeley Lab's Advanced Light Source (ALS) are typically deployed on operator consoles running Microsoft Windows 2000 and utilize EPICS[2]channel access for data access. In an effort to accommodate the wide variety of Windows based development tools and developers with little experience in network programming, ActiveX controls have been deployed on the operator stations. Use of ActiveX controls for use in the accelerator control environment has been presented previously[1]. Here we report on some of our experiences with the use and development of these controls.

A general method to determine sampling windows for nonlinear mixed effects models with an application to population pharmacokinetic studies.

PubMed

Foo, Lee Kien; McGree, James; Duffull, Stephen

2012-01-01

Optimal design methods have been proposed to determine the best sampling times when sparse blood sampling is required in clinical pharmacokinetic studies. However, the optimal blood sampling time points may not be feasible in clinical practice. Sampling windows, a time interval for blood sample collection, have been proposed to provide flexibility in blood sampling times while preserving efficient parameter estimation. Because of the complexity of the population pharmacokinetic models, which are generally nonlinear mixed effects models, there is no analytical solution available to determine sampling windows. We propose a method for determination of sampling windows based on MCMC sampling techniques. The proposed method attains a stationary distribution rapidly and provides time-sensitive windows around the optimal design points. The proposed method is applicable to determine sampling windows for any nonlinear mixed effects model although our work focuses on an application to population pharmacokinetic models. Copyright © 2012 John Wiley & Sons, Ltd.

Cross-modal integration of polyphonic characters in Chinese audio-visual sentences: a MVPA study based on functional connectivity.

PubMed

Zhang, Zhengyi; Zhang, Gaoyan; Zhang, Yuanyuan; Liu, Hong; Xu, Junhai; Liu, Baolin

2017-12-01

This study aimed to investigate the functional connectivity in the brain during the cross-modal integration of polyphonic characters in Chinese audio-visual sentences. The visual sentences were all semantically reasonable and the audible pronunciations of the polyphonic characters in corresponding sentences contexts varied in four conditions. To measure the functional connectivity, correlation, coherence and phase synchronization index (PSI) were used, and then multivariate pattern analysis was performed to detect the consensus functional connectivity patterns. These analyses were confined in the time windows of three event-related potential components of P200, N400 and late positive shift (LPS) to investigate the dynamic changes of the connectivity patterns at different cognitive stages. We found that when differentiating the polyphonic characters with abnormal pronunciations from that with the appreciate ones in audio-visual sentences, significant classification results were obtained based on the coherence in the time window of the P200 component, the correlation in the time window of the N400 component and the coherence and PSI in the time window the LPS component. Moreover, the spatial distributions in these time windows were also different, with the recruitment of frontal sites in the time window of the P200 component, the frontal-central-parietal regions in the time window of the N400 component and the central-parietal sites in the time window of the LPS component. These findings demonstrate that the functional interaction mechanisms are different at different stages of audio-visual integration of polyphonic characters.

A multimodal logistics service network design with time windows and environmental concerns

PubMed Central

Zhang, Dezhi; He, Runzhong; Wang, Zhongwei

2017-01-01

The design of a multimodal logistics service network with customer service time windows and environmental costs is an important and challenging issue. Accordingly, this work established a model to minimize the total cost of multimodal logistics service network design with time windows and environmental concerns. The proposed model incorporates CO2 emission costs to determine the optimal transportation mode combinations and investment selections for transfer nodes, which consider transport cost, transport time, carbon emission, and logistics service time window constraints. Furthermore, genetic and heuristic algorithms are proposed to set up the abovementioned optimal model. A numerical example is provided to validate the model and the abovementioned two algorithms. Then, comparisons of the performance of the two algorithms are provided. Finally, this work investigates the effects of the logistics service time windows and CO2 emission taxes on the optimal solution. Several important management insights are obtained. PMID:28934272

A multimodal logistics service network design with time windows and environmental concerns.

PubMed

Zhang, Dezhi; He, Runzhong; Li, Shuangyan; Wang, Zhongwei

2017-01-01

The design of a multimodal logistics service network with customer service time windows and environmental costs is an important and challenging issue. Accordingly, this work established a model to minimize the total cost of multimodal logistics service network design with time windows and environmental concerns. The proposed model incorporates CO2 emission costs to determine the optimal transportation mode combinations and investment selections for transfer nodes, which consider transport cost, transport time, carbon emission, and logistics service time window constraints. Furthermore, genetic and heuristic algorithms are proposed to set up the abovementioned optimal model. A numerical example is provided to validate the model and the abovementioned two algorithms. Then, comparisons of the performance of the two algorithms are provided. Finally, this work investigates the effects of the logistics service time windows and CO2 emission taxes on the optimal solution. Several important management insights are obtained.

Perilymph pharmacokinetics of locally-applied gentamicin in the guinea pig.

PubMed

Salt, A N; Hartsock, J J; Gill, R M; King, E; Kraus, F B; Plontke, S K

2016-12-01

Intratympanic gentamicin therapy is widely used clinically to suppress the vestibular symptoms of Meniere's disease. Dosing in humans was empirically established and we still know remarkably little about where gentamicin enters the inner ear, where it reaches in the inner ear and what time course it follows after local applications. In this study, gentamicin was applied to the round window niche as a 20 μL bolus of 40 mg/ml solution. Ten 2 μL samples of perilymph were collected sequentially from the lateral semi-circular canal (LSCC) at times from 1 to 4 h after application. Gentamicin concentration was typically highest in samples originating from the vestibule and was lower in samples originating from scala tympani. To interpret these results, perilymph elimination kinetics for gentamicin was quantified by loading the entire perilymph space by injection at the LSCC with a 500 μg/ml gentamicin solution followed by sequential perilymph sampling from the LSCC after different delay times. This allowed concentration decline in perilymph to be followed with time. Gentamicin was retained well in scala vestibuli and the vestibule but declined rapidly at the base of scala tympani, dominated by interactions of perilymph with CSF, as reported for other substances. Quantitative analysis, taking into account perilymph kinetics for gentamicin, showed that more gentamicin entered at the round window membrane (57%) than at the stapes (35%) but the lower concentrations found in scala tympani were due to greater losses there. The gentamicin levels found in perilymph of the vestibule, which are higher than would be expected from round window entry alone, undoubtedly contribute to the vestibulotoxic effects of the drug. Furthermore, calculations of gentamicin distribution following targeted applications to the RW or stapes are more consistent with cochleotoxicity depending on the gentamicin concentration in scala vestibuli rather than that in scala tympani. Copyright © 2016 Elsevier B.V. All rights reserved.

9. Historic American Buildings Survey, Bill Engdahl for HedrichBlessing, Photographers, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. Historic American Buildings Survey, Bill Engdahl for Hedrich-Blessing, Photographers, February, 1979 TYPICAL SMALL STAINED-GLASS WINDOW IN THE APSE. - Sacred Heart Roman Catholic Church, East Sixth & East Elizabeth Streets, Brownsville, Cameron County, TX

Response of an eddy-permitting ocean model to the assimilation of sparse in situ data

NASA Astrophysics Data System (ADS)

Li, Jian-Guo; Killworth, Peter D.; Smeed, David A.

2003-04-01

The response of an eddy-permitting ocean model to changes introduced by data assimilation is studied when the available in situ data are sparse in both space and time (typical for the majority of the ocean). Temperature and salinity (T&S) profiles from the WOCE upper ocean thermal data set were assimilated into a primitive equation ocean model over the North Atlantic, using a simple nudging scheme with a time window of about 2 days and a horizontal spatial radius of about 1°. When data are sparse the model returns to its unassimilated behavior, locally "forgetting" or rejecting the assimilation, on timescales determined by the local advection and diffusion. Increasing the spatial weighting radius effectively reduces both processes and hence lengthens the model restoring time (and with it, the impact of assimilation). Increasing the nudging factor enhances the assimilation effect but has little effect on the model restoring time.

Iterated local search algorithm for solving the orienteering problem with soft time windows.

PubMed

Aghezzaf, Brahim; Fahim, Hassan El

2016-01-01

In this paper we study the orienteering problem with time windows (OPTW) and the impact of relaxing the time windows on the profit collected by the vehicle. The way of relaxing time windows adopted in the orienteering problem with soft time windows (OPSTW) that we study in this research is a late service relaxation that allows linearly penalized late services to customers. We solve this problem heuristically by considering a hybrid iterated local search. The results of the computational study show that the proposed approach is able to achieve promising solutions on the OPTW test instances available in the literature, one new best solution is found. On the newly generated test instances of the OPSTW, the results show that the profit collected by the OPSTW is better than the profit collected by the OPTW.

Pairing of near-ultraviolet solar cells with electrochromic windows for smart management of the solar spectrum

NASA Astrophysics Data System (ADS)

Davy, Nicholas C.; Sezen-Edmonds, Melda; Gao, Jia; Lin, Xin; Liu, Amy; Yao, Nan; Kahn, Antoine; Loo, Yueh-Lin

2017-08-01

Current smart window technologies offer dynamic control of the optical transmission of the visible and near-infrared portions of the solar spectrum to reduce lighting, heating and cooling needs in buildings and to improve occupant comfort. Solar cells harvesting near-ultraviolet photons could satisfy the unmet need of powering such smart windows over the same spatial footprint without competing for visible or infrared photons, and without the same aesthetic and design constraints. Here, we report organic single-junction solar cells that selectively harvest near-ultraviolet photons, produce open-circuit voltages eclipsing 1.6 V and exhibit scalability in power generation, with active layers (10 cm2) substantially larger than those typical of demonstration organic solar cells (0.04-0.2 cm2). Integration of these solar cells with a low-cost, polymer-based electrochromic window enables intelligent management of the solar spectrum, with near-ultraviolet photons powering the regulation of visible and near-infrared photons for natural lighting and heating purposes.

A note on windowing for the waveform relaxation

NASA Technical Reports Server (NTRS)

Zhang, Hong

1994-01-01

The technique of windowing has been often used in the implementation of the waveform relaxations for solving ODE's or time dependent PDE's. Its efficiency depends upon problem stiffness and operator splitting. Using model problems, the estimates for window length and convergence rate are derived. The electiveness of windowing is then investigated for non-stiff and stiff cases respectively. lt concludes that for the former, windowing is highly recommended when a large discrepancy exists between the convergence rate on a time interval and the ones on its subintervals. For the latter, windowing does not provide any computational advantage if machine features are disregarded. The discussion is supported by experimental results.

Night-time naturally ventilated offices: Statistical simulations of window-use patterns from field monitoring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yun, Geun Young; Steemers, Koen

2010-07-15

This paper investigates occupant behaviour of window-use in night-time naturally ventilated offices on the basis of a pilot field study, conducted during the summers of 2006 and 2007 in Cambridge, UK, and then demonstrates the effects of employing night-time ventilation on indoor thermal conditions using predictive models of occupant window-use. A longitudinal field study shows that occupants make good use of night-time natural ventilation strategies when provided with openings that allow secure ventilation, and that there is a noticeable time of day effect in window-use patterns (i.e. increased probability of action on arrival and departure). We develop logistic models ofmore » window-use for night-time naturally ventilated offices, which are subsequently applied to a behaviour algorithm, including Markov chains and Monte Carlo methods. The simulations using the behaviour algorithm demonstrate a good agreement with the observational data of window-use, and reveal how building design and occupant behaviour collectively affect the thermal performance of offices. They illustrate that the provision of secure ventilation leads to more frequent use of the window, and thus contributes significantly to the achievement of a comfortable indoor environment during the daytime occupied period. For example, the maximum temperature for a night-time ventilated office is found to be 3 C below the predicted value for a daytime-only ventilated office. (author)« less

A Numerical Study of the Thermal Characteristics of an Air Cavity Formed by Window Sashes in a Double Window

NASA Astrophysics Data System (ADS)

Kang, Jae-sik; Oh, Eun-Joo; Bae, Min-Jung; Song, Doo-Sam

2017-12-01

Given that the Korean government is implementing what has been termed the energy standards and labelling program for windows, window companies will be required to assign window ratings based on the experimental results of their product. Because this has added to the cost and time required for laboratory tests by window companies, the simulation system for the thermal performance of windows has been prepared to compensate for time and cost burdens. In Korea, a simulator is usually used to calculate the thermal performance of a window through WINDOW/THERM, complying with ISO 15099. For a single window, the simulation results are similar to experimental results. A double window is also calculated using the same method, but the calculation results for this type of window are unreliable. ISO 15099 should not recommend the calculation of the thermal properties of an air cavity between window sashes in a double window. This causes a difference between simulation and experimental results pertaining to the thermal performance of a double window. In this paper, the thermal properties of air cavities between window sashes in a double window are analyzed through computational fluid dynamics (CFD) simulations with the results compared to calculation results certified by ISO 15099. The surface temperature of the air cavity analyzed by CFD is compared to the experimental temperatures. These results show that an appropriate calculation method for an air cavity between window sashes in a double window should be established for reliable thermal performance results for a double window.

Process Flow Features as a Host-Based Event Knowledge Representation

DTIC Science & Technology

2012-06-14

an executing process during a window of time called a process flow. Process flows are calculated from key process data structures extracted from...for Cluster 98. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 4.9. Davies- Boldin Dunn Index Sliding Window 5 on Windows 7...82 4.10. Davies- Boldin Dunn Index Sliding Window 10 on Windows 7 . 83 4.11. Davies- Boldin Dunn Index Sliding Window 20 on Windows 7 . 83 ix List of

Negative electro-mechanical windows are required for drug-induced Torsades de Pointes in the anesthetized guinea pig.

PubMed

Guns, P-J; Johnson, D M; Weltens, E; Lissens, J

2012-09-01

Assessment of the propensity of novel drugs to cause proarrhythmia is essential in the drug development process. It is increasingly recognized, however, that QT prolongation alone is an imperfect surrogate marker for Torsades de Pointes (TdP) arrhythmia prediction. In the present study we investigated the behavior of a novel surrogate marker for TdP, the electro-mechanical (E-M) window, prior to triggering of TdP episodes with sympathetic stimulation after administration of a number of reference compounds. Experiments were carried out in closed chest pentobarbital anesthetized guinea pigs. Test compounds were administered intravenously together with a specific I(Ks) blocker (JNJ303; 0.2 mgkg(-1)min(-1) for 3 min) and adrenaline (0.06 mgkg(-1)min(-1) for 2 min) was applied to trigger TdP. ECG, blood- and left ventricular pressure signals were measured continuously throughout the experiments. The E-M window i.e. the duration of the mechanical systole (QLVP(end) interval) minus the duration of the electrical activity (QT interval) was assessed for individual beats. Drugs with documented TdP liability (quinidine, haloperidol, domperidone, terfenadine, moxifloxacin, ciprofloxacin and dofetilide) produced TdP in the protocol after adrenaline infusion, whereas negative control compounds (verapamil, ranolazine, amiodarone and saline) did not cause TdP arrhythmia, even though increases in repolarization times were observed. TdP were typically preceded by large (greater than -50 ms) negative electro-mechanical windows and were accompanied by aftercontractions. The present study in anesthetized guinea pigs indicates that negative E-M windows are a prerequisite for sympathetically-driven TdP induction after the administration of various agents with known proarrhythmic potential. These data are a first step in the validation of this novel protocol; however we believe that this proarrhythmia model in small animals might be a valuable additional tool in the prediction of TdP risk of new chemical entities at the early stages of drug discovery. Copyright © 2012 Elsevier Inc. All rights reserved.

Program Predicts Performance of Optical Parametric Oscillators

NASA Technical Reports Server (NTRS)

Cross, Patricia L.; Bowers, Mark

2006-01-01

A computer program predicts the performances of solid-state lasers that operate at wavelengths from ultraviolet through mid-infrared and that comprise various combinations of stable and unstable resonators, optical parametric oscillators (OPOs), and sum-frequency generators (SFGs), including second-harmonic generators (SHGs). The input to the program describes the signal, idler, and pump beams; the SFG and OPO crystals; and the laser geometry. The program calculates the electric fields of the idler, pump, and output beams at three locations (inside the laser resonator, just outside the input mirror, and just outside the output mirror) as functions of time for the duration of the pump beam. For each beam, the electric field is used to calculate the fluence at the output mirror, plus summary parameters that include the centroid location, the radius of curvature of the wavefront leaving through the output mirror, the location and size of the beam waist, and a quantity known, variously, as a propagation constant or beam-quality factor. The program provides a typical Windows interface for entering data and selecting files. The program can include as many as six plot windows, each containing four graphs.

Quick Overview Scout 2008 Version 1.0

EPA Science Inventory

The Scout 2008 version 1.0 statistical software package has been updated from past DOS and Windows versions to provide classical and robust univariate and multivariate graphical and statistical methods that are not typically available in commercial or freeware statistical softwar...

Realtime Compositing of Procedural Facade Textures on the Gpu

NASA Astrophysics Data System (ADS)

Krecklau, L.; Kobbelt, L.

2011-09-01

The real time rendering of complex virtual city models has become more important in the last few years for many practical applications like realistic navigation or urban planning. For maximum rendering performance, the complexity of the geometry or textures can be reduced by decreasing the resolution until the data set can fully reside on the memory of the graphics card. This typically results in a low quality of the virtual city model. Alternatively, a streaming algorithm can load the high quality data set from the hard drive. However, this approach requires a large amount of persistent storage providing several gigabytes of static data. We present a system that uses a texture atlas containing atomic tiles like windows, doors or wall patterns, and that combines those elements on-the-fly directly on the graphics card. The presented approach benefits from a sophisticated randomization approach that produces lots of different facades while the grammar description itself remains small. By using a ray casting apporach, we are able to trace through transparent windows revealing procedurally generated rooms which further contributes to the realism of the rendering. The presented method enables real time rendering of city models with a high level of detail for facades while still relying on a small memory footprint.

Music chills: The eye pupil as a mirror to music's soul.

PubMed

Laeng, Bruno; Eidet, Lise Mette; Sulutvedt, Unni; Panksepp, Jaak

2016-08-01

This study evaluated whether music-induced aesthetic "chill" responses, which typically correspond to peak emotional experiences, can be objectively monitored by degree of pupillary dilation. Participants listened to self-chosen songs versus control songs chosen by other participants. The experiment included an active condition where participants made key presses to indicate when experiencing chills and a passive condition (without key presses). Chills were reported more frequently for self-selected songs than control songs. Pupil diameter was concurrently measured by an eye-tracker while participants listened to each of the songs. Pupil size was larger within specific time-windows around the chill events, as monitored by key responses, than in comparison to pupil size observed during 'passive' song listening. In addition, there was a clear relationship between pupil diameter within the chills-related time-windows during both active and passive conditions, thus ruling out the possibility that chills-related pupil dilations were an artifact of making a manual response. These findings strongly suggest that music chills can be visible in the moment-to-moment changes in the size of pupillary responses and that a neuromodulatory role of the central norepinephrine system is thereby implicated in this phenomenon. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Is Latency to Test Deadline a Predictor of Student Test Performance?

ERIC Educational Resources Information Center

Landrum, R. Eric; Gurung, Regan A. R.

2013-01-01

When students are given a period or window of time to take an exam, is taking an exam earlier in the window (high latency to deadline) related to test scores? In Study 1, students (n = 236) were given windows of time to take online each of 13 quizzes and 4 exams. In Study 2, students (n = 251) similarly took 4 exams online within a test window. In…

Sliding-window analysis tracks fluctuations in amygdala functional connectivity associated with physiological arousal and vigilance during fear conditioning.

PubMed

Baczkowski, Blazej M; Johnstone, Tom; Walter, Henrik; Erk, Susanne; Veer, Ilya M

2017-06-01

We evaluated whether sliding-window analysis can reveal functionally relevant brain network dynamics during a well-established fear conditioning paradigm. To this end, we tested if fMRI fluctuations in amygdala functional connectivity (FC) can be related to task-induced changes in physiological arousal and vigilance, as reflected in the skin conductance level (SCL). Thirty-two healthy individuals participated in the study. For the sliding-window analysis we used windows that were shifted by one volume at a time. Amygdala FC was calculated for each of these windows. Simultaneously acquired SCL time series were averaged over time frames that corresponded to the sliding-window FC analysis, which were subsequently regressed against the whole-brain seed-based amygdala sliding-window FC using the GLM. Surrogate time series were generated to test whether connectivity dynamics could have occurred by chance. In addition, results were contrasted against static amygdala FC and sliding-window FC of the primary visual cortex, which was chosen as a control seed, while a physio-physiological interaction (PPI) was performed as cross-validation. During periods of increased SCL, the left amygdala became more strongly coupled with the bilateral insula and anterior cingulate cortex, core areas of the salience network. The sliding-window analysis yielded a connectivity pattern that was unlikely to have occurred by chance, was spatially distinct from static amygdala FC and from sliding-window FC of the primary visual cortex, but was highly comparable to that of the PPI analysis. We conclude that sliding-window analysis can reveal functionally relevant fluctuations in connectivity in the context of an externally cued task. Copyright © 2017 Elsevier Inc. All rights reserved.

Handheld White Light Interferometer for Measuring Defect Depth in Windows

NASA Technical Reports Server (NTRS)

Youngquist, Robert; Simmons, Stephen; Cox, Robert

2010-01-01

Accurate quantification of defects (scratches and impacts) is vital to the certification of flight hardware and other critical components. The amount of damage to a particular component contributes to the performance, reliability, and safety of a system, which ultimately affects the success or failure of a mission or test. The launch-commit criteria on a Space Shuttle Orbiter window are governed by the depth of the defects that are identified by a visual inspection. This measurement of a defect is not easy to obtain given the environment, size of the defect, and location of the window(s). The determination of depth has typically been performed by taking a mold impression and measuring the impression with an optical profiling instrument. Another method of obtaining an estimate of the depth is by using a refocus microscope. To use a refocus microscope, the surface of the glass and bottom of the defect are, in turn, brought into focus by the operator. The amount of movement between the two points corresponds to the depth of the defect. The refocus microscope requires a skilled operator and has been proven to be unreliable when used on Orbiter windows. White light interferometry was chosen as a candidate to replace the refocus microscope. The White Light Interferometer (WLI) was developed to replace the refocus microscope as the instrument used for measuring the depth of defects in Orbiter windows. The WLI consists of a broadband illumination source, interferometer, detector, motion control, displacement sensor, mechanical housing, and support electronics. The illumination source for the WLI is typically a visible light emitting diode (LED) or a near-infrared superluminescent diode (SLD) with power levels of less than a milliwatt. The interferometer is a Michelson configuration consisting of a 1-in. (2.5-cm) cube beam splitter, a 0.5-in. (1.3-cm) optical window as a movable leg (used to closely match the return intensity of the fixed leg from the window), and a mirrored prism to fold the optics into the mechanical housing. The detector may be one of many C-mount CCD (charge-coupled device) cameras. Motion is provided by a commercial nanostepping motor with a serial interface. The displacement sensor is a custom device specifically designed for this application. The mechanical housing and support electronics were designed to integrate the various components into an instrument that could be physically handled by a technician and easily transported.

Computed Tomography Window Blending: Feasibility in Thoracic Trauma.

PubMed

Mandell, Jacob C; Wortman, Jeremy R; Rocha, Tatiana C; Folio, Les R; Andriole, Katherine P; Khurana, Bharti

2018-02-07

This study aims to demonstrate the feasibility of processing computed tomography (CT) images with a custom window blending algorithm that combines soft-tissue, bone, and lung window settings into a single image; to compare the time for interpretation of chest CT for thoracic trauma with window blending and conventional window settings; and to assess diagnostic performance of both techniques. Adobe Photoshop was scripted to process axial DICOM images from retrospective contrast-enhanced chest CTs performed for trauma with a window-blending algorithm. Two emergency radiologists independently interpreted the axial images from 103 chest CTs with both blended and conventional windows. Interpretation time and diagnostic performance were compared with Wilcoxon signed-rank test and McNemar test, respectively. Agreement with Nexus CT Chest injury severity was assessed with the weighted kappa statistic. A total of 13,295 images were processed without error. Interpretation was faster with window blending, resulting in a 20.3% time saving (P < .001), with no difference in diagnostic performance, within the power of the study to detect a difference in sensitivity of 5% as determined by post hoc power analysis. The sensitivity of the window-blended cases was 82.7%, compared to 81.6% for conventional windows. The specificity of the window-blended cases was 93.1%, compared to 90.5% for conventional windows. All injuries of major clinical significance (per Nexus CT Chest criteria) were correctly identified in all reading sessions, and all negative cases were correctly classified. All readers demonstrated near-perfect agreement with injury severity classification with both window settings. In this pilot study utilizing retrospective data, window blending allows faster preliminary interpretation of axial chest CT performed for trauma, with no significant difference in diagnostic performance compared to conventional window settings. Future studies would be required to assess the utility of window blending in clinical practice. Copyright © 2018 The Association of University Radiologists. All rights reserved.

Highly Flexible, Multipixelated Thermosensitive Smart Windows Made of Tough Hydrogels.

PubMed

La, Thanh-Giang; Li, Xinda; Kumar, Amit; Fu, Yiyang; Yang, Shu; Chung, Hyun-Joong

2017-09-27

In a cold night, a clear window that will become opaque while retaining the indoor heat is highly desirable for both privacy and energy efficiency. A thermally responsive material that controls both the transmittance of solar radiance (predominantly in the visible and near-infrared wavelengths) and blackbody radiation (mainly in the mid-infrared) can realize such windows with minimal energy consumption. Here, we report a smart coating made from polyampholyte hydrogel (PAH) that transforms from a transparency state to opacity to visible radiation and strengthens opacity to mid-infrared when lowering the temperature as a result of phase separation between the water-rich and polymer-rich phases. To match a typical temperature fluctuation during the day, we fine-tune the phase transition temperature between 25 and 55 °C by introducing a small amount of relatively hydrophobic monomers (0.1 to 0.5 wt % to PAH). To further demonstrate an actively controlled, highly flexible, and high-contrast smart window, we build in an array of electric heaters made of printed elastomeric composite. The multipixelated window offers rapid switching, ∼70 s per cycle, whereas the device can withstand high strain (up to 80%) during operations.

CMOS VLSI Active-Pixel Sensor for Tracking

NASA Technical Reports Server (NTRS)

Pain, Bedabrata; Sun, Chao; Yang, Guang; Heynssens, Julie

2004-01-01

An architecture for a proposed active-pixel sensor (APS) and a design to implement the architecture in a complementary metal oxide semiconductor (CMOS) very-large-scale integrated (VLSI) circuit provide for some advanced features that are expected to be especially desirable for tracking pointlike features of stars. The architecture would also make this APS suitable for robotic- vision and general pointing and tracking applications. CMOS imagers in general are well suited for pointing and tracking because they can be configured for random access to selected pixels and to provide readout from windows of interest within their fields of view. However, until now, the architectures of CMOS imagers have not supported multiwindow operation or low-noise data collection. Moreover, smearing and motion artifacts in collected images have made prior CMOS imagers unsuitable for tracking applications. The proposed CMOS imager (see figure) would include an array of 1,024 by 1,024 pixels containing high-performance photodiode-based APS circuitry. The pixel pitch would be 9 m. The operations of the pixel circuits would be sequenced and otherwise controlled by an on-chip timing and control block, which would enable the collection of image data, during a single frame period, from either the full frame (that is, all 1,024 1,024 pixels) or from within as many as 8 different arbitrarily placed windows as large as 8 by 8 pixels each. A typical prior CMOS APS operates in a row-at-a-time ( grolling-shutter h) readout mode, which gives rise to exposure skew. In contrast, the proposed APS would operate in a sample-first/readlater mode, suppressing rolling-shutter effects. In this mode, the analog readout signals from the pixels corresponding to the windows of the interest (which windows, in the star-tracking application, would presumably contain guide stars) would be sampled rapidly by routing them through a programmable diagonal switch array to an on-chip parallel analog memory array. The diagonal-switch and memory addresses would be generated by the on-chip controller. The memory array would be large enough to hold differential signals acquired from all 8 windows during a frame period. Following the rapid sampling from all the windows, the contents of the memory array would be read out sequentially by use of a capacitive transimpedance amplifier (CTIA) at a maximum data rate of 10 MHz. This data rate is compatible with an update rate of almost 10 Hz, even in full-frame operation

Ultrasound window-modulated compounding Nakagami imaging: Resolution improvement and computational acceleration for liver characterization.

PubMed

Ma, Hsiang-Yang; Lin, Ying-Hsiu; Wang, Chiao-Yin; Chen, Chiung-Nien; Ho, Ming-Chih; Tsui, Po-Hsiang

2016-08-01

Ultrasound Nakagami imaging is an attractive method for visualizing changes in envelope statistics. Window-modulated compounding (WMC) Nakagami imaging was reported to improve image smoothness. The sliding window technique is typically used for constructing ultrasound parametric and Nakagami images. Using a large window overlap ratio may improve the WMC Nakagami image resolution but reduces computational efficiency. Therefore, the objectives of this study include: (i) exploring the effects of the window overlap ratio on the resolution and smoothness of WMC Nakagami images; (ii) proposing a fast algorithm that is based on the convolution operator (FACO) to accelerate WMC Nakagami imaging. Computer simulations and preliminary clinical tests on liver fibrosis samples (n=48) were performed to validate the FACO-based WMC Nakagami imaging. The results demonstrated that the width of the autocorrelation function and the parameter distribution of the WMC Nakagami image reduce with the increase in the window overlap ratio. One-pixel shifting (i.e., sliding the window on the image data in steps of one pixel for parametric imaging) as the maximum overlap ratio significantly improves the WMC Nakagami image quality. Concurrently, the proposed FACO method combined with a computational platform that optimizes the matrix computation can accelerate WMC Nakagami imaging, allowing the detection of liver fibrosis-induced changes in envelope statistics. FACO-accelerated WMC Nakagami imaging is a new-generation Nakagami imaging technique with an improved image quality and fast computation. Copyright © 2016 Elsevier B.V. All rights reserved.

Atomically Thin Graphene Windows That Enable High Contrast Electron Microscopy without a Specimen Vacuum Chamber.

PubMed

Han, Yimo; Nguyen, Kayla X; Ogawa, Yui; Park, Jiwoong; Muller, David A

2016-12-14

Scanning electron microscopes (SEMs) require a high vacuum environment to generate and shape an electron beam for imaging; however, the vacuum conditions greatly limit the nature of specimens that can be examined. From a purely scattering physics perspective, it is not necessary to place the specimen inside the vacuum chamber-the mean free paths (MFPs) for electron scattering in air at typical SEM beam voltages are 50-100 μm. This is the idea behind the airSEM, which removes the specimen vacuum chamber from the SEM and places the sample in air. The thickness of the gas layer is less than a MFP from an electron-transparent window to preserve the shape and resolution of the incident beam, resulting in comparable imaging quality to an all-vacuum SEM. Present silicon nitride windows scatter far more strongly than the air gap and are currently the contrast and resolution limiting factor in the airSEM. Graphene windows have been used previously to wrap or seal samples in vacuum for imaging. Here we demonstrate the use of a robust bilayer graphene window for sealing the electron optics from the room environment, providing an electron transparent window with only a 2% drop in contrast. There is a 5-fold-increase in signal/noise ratio for imaging compared to multi-MFP-thick silicon nitride windows, enabling high contrast in backscattered, transmission, and surface imaging modes for the new airSEM geometry.

21. DETAIL EXTERIOR VIEW OF TWOSTORY OFFICE AT NORTH CORNER ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

21. DETAIL EXTERIOR VIEW OF TWO-STORY OFFICE AT NORTH CORNER OF BUILDING, SHOWING STAIRWAY, SASH WINDOWS, AND TYPICAL COLUMN WITH ROUND CONCRETE BASE - Oakland Army Base, Transit Shed, East of Dunkirk Street & South of Burma Road, Oakland, Alameda County, CA

Apparatus for Teaching Physics.

ERIC Educational Resources Information Center

Gottlieb, Herbert H., Ed.

1981-01-01

Describes an apparatus for plotting electric fields using burglar alarm window tape for electrodes and carbonized electronic stencil paper as sheet resistance. Also describes a simple pentode modulator circuit which will modulate a typical helium-neon gas laser, providing an audio channel for demonstration purposes. (SK)

Nonlinear Prediction As A Tool For Determining Parameters For Phase Space Reconstruction In Meteorology

NASA Astrophysics Data System (ADS)

Miksovsky, J.; Raidl, A.

Time delays phase space reconstruction represents one of useful tools of nonlinear time series analysis, enabling number of applications. Its utilization requires the value of time delay to be known, as well as the value of embedding dimension. There are sev- eral methods how to estimate both these parameters. Typically, time delay is computed first, followed by embedding dimension. Our presented approach is slightly different - we reconstructed phase space for various combinations of mentioned parameters and used it for prediction by means of the nearest neighbours in the phase space. Then some measure of prediction's success was computed (correlation or RMSE, e.g.). The position of its global maximum (minimum) should indicate the suitable combination of time delay and embedding dimension. Several meteorological (particularly clima- tological) time series were used for the computations. We have also created a MS- Windows based program in order to implement this approach - its basic features will be presented as well.

Cross-stiffened continuous fiber structures

NASA Technical Reports Server (NTRS)

Ewen, John R.; Suarez, Jim A.

1993-01-01

Under NASA's Novel Composites for Wing and Fuselage Applications (NCWFA) program, Contract NAS1-18784, Grumman is evaluating the structural efficiency of graphite/epoxy cross-stiffened panel elements fabricated using innovative textile preforms and cost effective Resin Transfer Molding (RTM) and Resin Film Infusion (RFI) processes. Two three-dimensional woven preform assembly concepts have been defined for application to a representative window belt design typically found in a commercial transport airframe. The 3D woven architecture for each of these concepts is different; one is vertically woven in the plane of the window belt geometry and the other is loom woven in a compressed state similar to an unfolded eggcrate. The feasibility of both designs has been demonstrated in the fabrication of small test element assemblies. These elements and the final window belt assemblies will be structurally tested, and results compared.

Acoustical and thermal performance of exterior residential walls, doors, and windows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sabine, H.J.; Lacher, M.B.; Flynn, D.R.

1975-11-01

Laboratory tests of sound transmission loss, thermal transmittance, and rate of air leakage were conducted on full scale (9 feet high x 14 feet wide; 2.7 x 4.3 meters) specimens of typical residential exterior wall constructions, either unbroken or penetrated by a door or window. The walls were of wood frame construction with gypsum board drywall interior finish and exterior finishes of wood siding, stucco, or brick veneer. Additional accoustical tests were run on a number of individual doors and windows. A total of 109 acoustical tests and 48 thermal tests are reported. The resultant data are compared with literaturemore » data on similar constructions. Correlations developed among the several quantities measured will assist more rational design where both energy conservation and noise isolation must be considered. (130 references) (auth)« less

Lagged kernel machine regression for identifying time windows of susceptibility to exposures of complex mixtures.

PubMed

Liu, Shelley H; Bobb, Jennifer F; Lee, Kyu Ha; Gennings, Chris; Claus Henn, Birgit; Bellinger, David; Austin, Christine; Schnaas, Lourdes; Tellez-Rojo, Martha M; Hu, Howard; Wright, Robert O; Arora, Manish; Coull, Brent A

2018-07-01

The impact of neurotoxic chemical mixtures on children's health is a critical public health concern. It is well known that during early life, toxic exposures may impact cognitive function during critical time intervals of increased vulnerability, known as windows of susceptibility. Knowledge on time windows of susceptibility can help inform treatment and prevention strategies, as chemical mixtures may affect a developmental process that is operating at a specific life phase. There are several statistical challenges in estimating the health effects of time-varying exposures to multi-pollutant mixtures, such as: multi-collinearity among the exposures both within time points and across time points, and complex exposure-response relationships. To address these concerns, we develop a flexible statistical method, called lagged kernel machine regression (LKMR). LKMR identifies critical exposure windows of chemical mixtures, and accounts for complex non-linear and non-additive effects of the mixture at any given exposure window. Specifically, LKMR estimates how the effects of a mixture of exposures change with the exposure time window using a Bayesian formulation of a grouped, fused lasso penalty within a kernel machine regression (KMR) framework. A simulation study demonstrates the performance of LKMR under realistic exposure-response scenarios, and demonstrates large gains over approaches that consider each time window separately, particularly when serial correlation among the time-varying exposures is high. Furthermore, LKMR demonstrates gains over another approach that inputs all time-specific chemical concentrations together into a single KMR. We apply LKMR to estimate associations between neurodevelopment and metal mixtures in Early Life Exposures in Mexico and Neurotoxicology, a prospective cohort study of child health in Mexico City.

Increases in Perspective Embedding Increase Reading Time Even with Typical Text Presentation: Implications for the Reading of Literature

PubMed Central

Whalen, D. H.; Zunshine, Lisa; Holquist, Michael

2015-01-01

Reading fiction is a major component of intellectual life, yet it has proven difficult to study experimentally. One aspect of literature that has recently come to light is perspective embedding (“she thought I left” embedding her perspective on “I left”), which seems to be a defining feature of fiction. Previous work (Whalen et al., 2012) has shown that increasing levels of embedment affects the time that it takes readers to read and understand short vignettes in a moving window paradigm. With increasing levels of embedment from 1 to 5, reading times in a moving window paradigm rose almost linearly. However, level 0 was as slow as 3–4. Accuracy on probe questions was relatively constant until dropping at the fifth level. Here, we assessed this effect in a more ecologically valid (“typical”) reading paradigm, in which the entire vignette was visible at once, either for as long as desired (Experiment 1) or a fixed time (Experiment 2). In Experiment 1, reading times followed a pattern similar to that of the previous experiment, with some differences in absolute speed. Accuracy matched previous results: fairly consistent accuracy until a decline at level 5, indicating that both presentation methods allowed understanding. In Experiment 2, accuracy was somewhat reduced, perhaps because participants were less successful at allocating their attention than they were during the earlier experiment; however, the pattern was the same. It seems that literature does not, on average, use easiest reading level but rather uses a middle ground that challenges the reader, but not too much. PMID:26635684

Anomalous finite-size effects in the Battle of the Sexes

NASA Astrophysics Data System (ADS)

Cremer, J.; Reichenbach, T.; Frey, E.

2008-06-01

The Battle of the Sexes describes asymmetric conflicts in mating behavior of males and females. Males can be philanderer or faithful, while females are either fast or coy, leading to a cyclic dynamics. The adjusted replicator equation predicts stable coexistence of all four strategies. In this situation, we consider the effects of fluctuations stemming from a finite population size. We show that they unavoidably lead to extinction of two strategies in the population. However, the typical time until extinction occurs strongly prolongs with increasing system size. In the emerging time window, a quasi-stationary probability distribution forms that is anomalously flat in the vicinity of the coexistence state. This behavior originates in a vanishing linear deterministic drift near the fixed point. We provide numerical data as well as an analytical approach to the mean extinction time and the quasi-stationary probability distribution.

Standardization of pitch-range settings in voice acoustic analysis.

PubMed

Vogel, Adam P; Maruff, Paul; Snyder, Peter J; Mundt, James C

2009-05-01

Voice acoustic analysis is typically a labor-intensive, time-consuming process that requires the application of idiosyncratic parameters tailored to individual aspects of the speech signal. Such processes limit the efficiency and utility of voice analysis in clinical practice as well as in applied research and development. In the present study, we analyzed 1,120 voice files, using standard techniques (case-by-case hand analysis), taking roughly 10 work weeks of personnel time to complete. The results were compared with the analytic output of several automated analysis scripts that made use of preset pitch-range parameters. After pitch windows were selected to appropriately account for sex differences, the automated analysis scripts reduced processing time of the 1,120 speech samples to less than 2.5 h and produced results comparable to those obtained with hand analysis. However, caution should be exercised when applying the suggested preset values to pathological voice populations.

Investigating the Impact of Maternal Residential Mobility on Identifying Critical Windows of Susceptibility to Ambient Air Pollution During Pregnancy.

PubMed

Warren, Joshua L; Son, Ji-Young; Pereira, Gavin; Leaderer, Brian P; Bell, Michelle L

2018-05-01

Identifying periods of increased vulnerability to air pollution during pregnancy with respect to the development of adverse birth outcomes can improve understanding of possible mechanisms of disease development and provide guidelines for protection of the child. Exposure to air pollution during pregnancy is typically based on the mother's residence at delivery, potentially resulting in exposure misclassification and biasing the estimation of critical windows of pregnancy. In this study, we determined the impact of maternal residential mobility during pregnancy on defining weekly exposure to particulate matter less than or equal to 10 μm in aerodynamic diameter (PM10) and estimating windows of susceptibility to term low birth weight. We utilized data sets from 4 Connecticut birth cohorts (1988-2008) that included information on all residential addresses between conception and delivery for each woman. We designed a simulation study to investigate the impact of increasing levels of mobility on identification of critical windows. Increased PM10 exposure during pregnancy weeks 16-18 was associated with an increased probability of term low birth weight. Ignoring residential mobility when defining weekly exposure had only a minor impact on the identification of critical windows for PM10 and term low birth weight in the data application and simulation study. Identification of critical pregnancy windows was robust to exposure misclassification caused by ignoring residential mobility in these Connecticut birth cohorts.

Development of an EMCCD for LIDAR applications

NASA Astrophysics Data System (ADS)

De Monte, B.; Bell, R. T.

2017-11-01

A novel detector, incorporating e2v's EMCCD (L3VisionTM) [1] technology for use in LIDAR (Light Detection And Ranging) applications has been designed, manufactured and characterised. The most critical performance aspect was the requirement to collect charge from a 120μm square detection area for a 667ns temporal sampling window, with low crosstalk between successive samples, followed by signal readout with sub-electron effective noise. Additional requirements included low dark signal, high quantum efficiency at the 355nm laser wavelength and the ability to handle bright laser echoes, without corruption of the much fainter useful signals. The detector architecture used high speed charge binning to combine signal from each sampling window into a single charge packet. This was then passed through a multiplication register (EMCCD) operating with a typical gain of 100X to a conventional charge detection circuit. The detector achieved a typical quantum efficiency of 80% and a total noise in darkness of < 0.5 electrons rms. Development of the detector was supported by ESA.

A test of multiple correlation temporal window characteristic of non-Markov processes

NASA Astrophysics Data System (ADS)

Arecchi, F. T.; Farini, A.; Megna, N.

2016-03-01

We introduce a sensitive test of memory effects in successive events. The test consists of a combination K of binary correlations at successive times. K decays monotonically from K = 1 for uncorrelated events as a Markov process. For a monotonic memory fading, K<1 always. Here we report evidence of a K>1 temporal window in cognitive tasks consisting of the visual identification of the front face of the Necker cube after a previous presentation of the same. We speculate that memory effects provide a temporal window with K>1 and this experiment could be a possible first step towards a better comprehension of this phenomenon. The K>1 behaviour is maximal at an inter-measurement time τ around 2s with inter-subject differences. The K>1 persists over a time window of 1s around τ; outside this window the K<1 behaviour is recovered. The universal occurrence of a K>1 window in pairs of successive perceptions suggests that, at variance with single visual stimuli eliciting a suitable response, a pair of stimuli shortly separated in time displays mutual correlations.

A new version of a computer program for dynamical calculations of RHEED intensity oscillations

NASA Astrophysics Data System (ADS)

Daniluk, Andrzej; Skrobas, Kazimierz

2006-01-01

We present a new version of the RHEED program which contains a graphical user interface enabling the use of the program in the graphical environment. The presented program also contains a graphical component which enables displaying program data at run-time through an easy-to-use graphical interface. New version program summaryTitle of program: RHEEDGr Catalogue identifier: ADWV Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADWV Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Catalogue identifier of previous version: ADUY Authors of the original program: A. Daniluk Does the new version supersede the original program: no Computer for which the new version is designed and others on which it has been tested: Pentium-based PC Operating systems or monitors under which the new version has been tested: Windows 9x, XP, NT Programming language used: Borland C++ Builder Memory required to execute with typical data: more than 1 MB Number of bits in a word: 64 bits Number of processors used: 1 Number of lines in distributed program, including test data, etc.: 5797 Number of bytes in distributed program, including test data, etc.: 588 121 Distribution format: tar.gz Nature of physical problem: Reflection high-energy electron diffraction (RHEED) is a very useful technique for studying growth and surface analysis of thin epitaxial structures prepared by the molecular beam epitaxy (MBE). The RHEED technique can reveal, almost instantaneously, changes either in the coverage of the sample surface by adsorbates or in the surface structure of a thin film. Method of solution: RHEED intensities are calculated within the framework of the general matrix formulation of Peng and Whelan [1] under the one-beam condition. Reasons for the new version: Responding to the user feedback we designed a graphical package that enables displaying program data at run-time through an easy-to-use graphical interface. Summary of revisions:In the present form the code is an object-oriented extension of previous version [2]. Fig. 1 shows the static structure of classes and their possible relationships (i.e. inheritance, association, aggregation and dependency) in the code. The code has been modified and optimized to compile under the C++ Builder integrated development environment (IDE). A graphical user interface (GUI) for the program has been created. The application is a standard multiple document interface (MDI) project from Builder's object repository. The MDI application spawns child window that reside within the client window; the main form contains child object. We have added an original graphical component [3] which has been tested successfully in the C++ Builder programming environment under Microsoft Windows platform. Fig. 2 shows internal structure of the component. This diagram is a graphic presentation of the static view which shows a collection of declarative model elements, such as classes, types, and their relationships. Each of the model elements shown in Fig. 2 is manifested by one header file Graph2D.h, and one code file Graph2D.cpp. Fig. 3 sets the stage by showing the package which supplies the C++ Builder elements used in the component. Installation instructions of the TGraph2D.bpk package can be found in the new distribution. The program has been constructed according to the systems development live cycle (SDLC) methodology [4]. Typical running time: The typical running time is machine and user-parameters dependent. Unusual features of the program: The program is distributed in the form of a main project RHEEDGr.bpr with associated files, and should be compiled using Borland C++ Builder compilers version 5 or later.

Dip-dependent variations in LFE duration during ETS events

NASA Astrophysics Data System (ADS)

Chestler, S.; Creager, K.; Ghosh, A.

2015-12-01

Using data from the Array of Arrays experiment, we create a new, more spatially complete catalog of LFEs beneath the Olympic Peninsula, WA. Using stacked waveforms produced by stacking 1-minute windows of data from each array over the slowness with the greatest power [Ghosh et al., 2012], we pick out peaks in tremor activity that are consistent over multiple arrays. These peaks are potential LFE detections. Fifteen-second windows of raw data centered on each peak are scanned through time. If the waveform repeats, the detection is used as a new LFE family. Template waveforms for each family are created by stacking all windows that correlate with the initial detection. During an ETS event, activity at a given point on the plate interface (i.e. the activity of an LFE family) typically lasts for 3.5 (downdip) to 5 days (updip). Activity generally begins with a flurry of LFEs lasting 8 hours (downdip) to 20 hours (updip) followed by many short bursts of activity separated by 5 hours or more. Updip families have more bursts (5-10) than downdip families (2-5 bursts). The later bursts often occur during times of encouraging tidal shear stress, while the initial flurries have no significant correlation with tides. While updip LFE families are more active during ETS events than downdip families, they seldom light up between ETS events, which only occur every 12-14 months. On the other hand, downdip LFE families are active much more frequently during the year; the most down-dip families exhibit activity every week or so. Because updip families are rarely active between ETS events, it is possible that little stress is released updip during inter-ETS time periods. Hence during ETS events more stress needs to be released updip than downdip, consistent with the longer-duration activity of updip LFE families.

The joint time-frequency spectrogram structure of heptanes boilover noise

NASA Astrophysics Data System (ADS)

Xu, Qiang

2006-04-01

An experiment was conducted to study the noise characteristics in the boilover phenomena. The boilover occurs in the combustion of a liquid fuel floating on water. It will cause a sharp increase in burning rate and external radiation. Explosive burning of the fuel would cause potential safety consequence. Combustion noise accompanies the development of fire and displays different characteristics in typical period. These characteristics can be used to predict the start time of boilover. The acoustic signal in boilover procedure during the combustion of heptanes-water mixture is obtained in a set of experiments. Joint time-frequency analysis (JTFA) method is applied in the treatment of noise data. Several JTFA algorithms were used in the evaluation. These algorithms include Gabor, adaptive spectrogram, cone shape distribution, choi-williams distribution, Wigner-Ville Distribution, and Short Time Fourier Transform with different windows such as rectangular, Blackman, Hamming and Hanning. Time-frequency distribution patterns of the combustion noise are obtained, and they are compared with others from jet flow and small plastic bubble blow up.

Efficient constraint handling in electromagnetism-like algorithm for traveling salesman problem with time windows.

PubMed

Yurtkuran, Alkın; Emel, Erdal

2014-01-01

The traveling salesman problem with time windows (TSPTW) is a variant of the traveling salesman problem in which each customer should be visited within a given time window. In this paper, we propose an electromagnetism-like algorithm (EMA) that uses a new constraint handling technique to minimize the travel cost in TSPTW problems. The EMA utilizes the attraction-repulsion mechanism between charged particles in a multidimensional space for global optimization. This paper investigates the problem-specific constraint handling capability of the EMA framework using a new variable bounding strategy, in which real-coded particle's boundary constraints associated with the corresponding time windows of customers, is introduced and combined with the penalty approach to eliminate infeasibilities regarding time window violations. The performance of the proposed algorithm and the effectiveness of the constraint handling technique have been studied extensively, comparing it to that of state-of-the-art metaheuristics using several sets of benchmark problems reported in the literature. The results of the numerical experiments show that the EMA generates feasible and near-optimal results within shorter computational times compared to the test algorithms.

Efficient Constraint Handling in Electromagnetism-Like Algorithm for Traveling Salesman Problem with Time Windows

PubMed Central

Yurtkuran, Alkın

2014-01-01

The traveling salesman problem with time windows (TSPTW) is a variant of the traveling salesman problem in which each customer should be visited within a given time window. In this paper, we propose an electromagnetism-like algorithm (EMA) that uses a new constraint handling technique to minimize the travel cost in TSPTW problems. The EMA utilizes the attraction-repulsion mechanism between charged particles in a multidimensional space for global optimization. This paper investigates the problem-specific constraint handling capability of the EMA framework using a new variable bounding strategy, in which real-coded particle's boundary constraints associated with the corresponding time windows of customers, is introduced and combined with the penalty approach to eliminate infeasibilities regarding time window violations. The performance of the proposed algorithm and the effectiveness of the constraint handling technique have been studied extensively, comparing it to that of state-of-the-art metaheuristics using several sets of benchmark problems reported in the literature. The results of the numerical experiments show that the EMA generates feasible and near-optimal results within shorter computational times compared to the test algorithms. PMID:24723834

A probabilistic method for the estimation of residual risk in donated blood.

PubMed

Bish, Ebru K; Ragavan, Prasanna K; Bish, Douglas R; Slonim, Anthony D; Stramer, Susan L

2014-10-01

The residual risk (RR) of transfusion-transmitted infections, including the human immunodeficiency virus and hepatitis B and C viruses, is typically estimated by the incidence[Formula: see text]window period model, which relies on the following restrictive assumptions: Each screening test, with probability 1, (1) detects an infected unit outside of the test's window period; (2) fails to detect an infected unit within the window period; and (3) correctly identifies an infection-free unit. These assumptions need not hold in practice due to random or systemic errors and individual variations in the window period. We develop a probability model that accurately estimates the RR by relaxing these assumptions, and quantify their impact using a published cost-effectiveness study and also within an optimization model. These assumptions lead to inaccurate estimates in cost-effectiveness studies and to sub-optimal solutions in the optimization model. The testing solution generated by the optimization model translates into fewer expected infections without an increase in the testing cost. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The noise environment of a school classroom due to the operation of utility helicopters. [acoustic measurements of helicopter noise during flight over building

NASA Technical Reports Server (NTRS)

Hilton, D. A.; Pegg, R. J.

1974-01-01

Noise measurements under controlled conditions have been made inside and outside of a school building during flyover operations of four different helicopters. The helicopters were operated at a condition considered typical for a police patrol mission. Flyovers were made at an altitude of 500 ft and an airspeed of 45 miles per hour. During these operations acoustic measurements were made inside and outside of the school building with the windows closed and then open. The outside noise measurements during helicopter flyovers indicate that the outside db(A) levels were approximately the same for all test helicopters. For the windows closed case, significant reductions for the inside measured db(A) values were noted for all overflights. These reductions were approximately 20 db(A); similar reductions were noted in other subjective measuring units. The measured internal db(A) levels with the windows open exceeded published classroom noise criteria values; however, for the windows-closed case they are in general agreement with the criteria values.

75 FR 11841 - Repowering Assistance Program

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-12

... application window. SUMMARY: RBS is announcing a new application window to submit applications for the...-time application window for remaining FY 2009 funds. Paperwork Reduction Act In accordance with the... allocate all of the FY 2009 authorized funds. Therefore, the Agency is opening a new application window to...

Millisecond timing on PCs and Macs.

PubMed

MacInnes, W J; Taylor, T L

2001-05-01

A real-time, object-oriented solution for displaying stimuli on Windows 95/98, MacOS and Linux platforms is presented. The program, written in C++, utilizes a special-purpose window class (GLWindow), OpenGL, and 32-bit graphics acceleration; it avoids display timing uncertainty by substituting the new window class for the default window code for each system. We report the outcome of tests for real-time capability across PC and Mac platforms running a variety of operating systems. The test program, which can be used as a shell for programming real-time experiments and testing specific processors, is available at http://www.cs.dal.ca/~macinnwj. We propose to provide researchers with a sense of the usefulness of our program, highlight the ability of many multitasking environments to achieve real time, as well as caution users about systems that may not achieve real time, even under optimal conditions.

Exclusive queueing model including the choice of service windows

NASA Astrophysics Data System (ADS)

Tanaka, Masahiro; Yanagisawa, Daichi; Nishinari, Katsuhiro

2018-01-01

In a queueing system involving multiple service windows, choice behavior is a significant concern. This paper incorporates the choice of service windows into a queueing model with a floor represented by discrete cells. We contrived a logit-based choice algorithm for agents considering the numbers of agents and the distances to all service windows. Simulations were conducted with various parameters of agent choice preference for these two elements and for different floor configurations, including the floor length and the number of service windows. We investigated the model from the viewpoint of transit times and entrance block rates. The influences of the parameters on these factors were surveyed in detail and we determined that there are optimum floor lengths that minimize the transit times. In addition, we observed that the transit times were determined almost entirely by the entrance block rates. The results of the presented model are relevant to understanding queueing systems including the choice of service windows and can be employed to optimize facility design and floor management.

Mitigating residential exposure to secondhand tobacco smoke

NASA Astrophysics Data System (ADS)

Klepeis, Neil E.; Nazaroff, William W.

In a companion paper, we used a simulation model to explore secondhand tobacco smoke (SHS) exposures for typical conditions in residences. In the current paper, we extend this analysis to evaluate the effectiveness of physical mitigation approaches in reducing nonsmokers' exposure to airborne SHS particulate matter in a hypothetical 6-zone house. Measures investigated included closing doors or opening windows in response to smoking activity, modifying location patterns to segregate the nonsmoker and the active smoker, and operating particle filtration devices. We first performed 24 scripted simulation trials using hypothetical patterns of occupant location. We then performed cohort simulation trials across 25 mitigation scenarios using over 1000 pairs of nonsmoker and smoker time-location patterns that were selected from a survey of human activity patterns in US homes. We limited cohort pairs to cases where more than 10 cigarettes were smoked indoors at home each day and the nonsmoker was at home for more than two thirds of the day. We evaluated the effectiveness of each mitigation approach by examining its impact on the simulated frequency distribution of residential SHS particle exposure. The two most effective strategies were the isolation of the smoker in a closed room with an open window, and a ban on smoking whenever the nonsmoker was at home. The use of open windows to supply local or cross ventilation, or the operation of portable filtration devices in smoking rooms, provided moderate exposure reductions. Closed doors, by themselves, were not effective.

Correlates of avian building strikes at a glass façade museum surrounded by avian habitat

NASA Astrophysics Data System (ADS)

Kahle, L.; Flannery, M.; Dumbacher, J. P.

2013-12-01

Bird window collisions are the second largest anthropogenic cause of bird deaths in the world. Effective mitigation requires an understanding of which birds are most likely to strike, when, and why. Here, we examine five years of avian window strike data from the California Academy of Sciences - a relatively new museum with significant glass façade situated in Golden Gate Park, San Francisco. We examine correlates of window-killed birds, including age, sex, season, and migratory or sedentary tendencies of the birds. We also examine correlates of window kills such as presence of habitat surrounding the building and overall window area. We found that males are almost three times more likely than females to mortally strike windows, and immature birds are three times more abundant than adults in our window kill dataset. Among seasons, strikes were not notably different in spring, summer, and fall; however they were notably reduced in winter. There was no statistical effect of building orientation (north, south, east, or west), and the presence of avian habitat directly adjacent to windows had a minor effect. We also report ongoing studies examining various efforts to reduce window kill (primarily external decals and large electronic window blinds.) We hope that improving our understanding of the causes of the window strikes will help us strategically reduce window strikes.

Window to the World

ERIC Educational Resources Information Center

Cannon, Kama

2018-01-01

Although formal papers are typical, sometimes posters or other visual presentations are more useful tools for sharing visual-spatial information. By incorporating creativity and technology into the study of geographical science, STEM (the study of Science, Technology Engineering, and Mathematics) is changed to STEAM (the A stands for ART)! The…

Mirrors & Windows into Student Noticing

ERIC Educational Resources Information Center

Dominguez, Higinio

2016-01-01

In many classrooms, students solve problems posed by others--teachers, textbooks, and test materials. These problems typically describe a contrived situation followed by a question about an unknown that students are expected to resolve. Unsurprisingly, many students avoid reading these problems for meaning and instead engage in a suspension of…

A novel fast optical switch based on two cascaded Terahertz Optical Asymmetric Demultiplexers (TOAD).

PubMed

Wang, Bing; Baby, Varghese; Tong, Wilson; Xu, Lei; Friedman, Michelle; Runser, Robert; Glesk, Ivan; Prucnal, Paul

2002-01-14

A novel optical switch based on cascading two terahertz optical asymmetric demultiplexers (TOAD) is presented. By utilizing the sharp edge of the asymmetric TOAD switching window profile, two TOAD switching windows are overlapped to produce a narrower aggregate switching window, not limited by the pulse propagation time in the SOA of the TOAD. Simulations of the cascaded TOAD switching window show relatively constant window amplitude for different window sizes. Experimental results on cascading two TOADs, each with a switching window of 8ps, but with the SOA on opposite sides of the fiber loop, show a minimum switching window of 2.7ps.

Life test results for an ensemble of CO2 lasers

NASA Technical Reports Server (NTRS)

Peruso, C. J.; Degnan, J. J.; Hochuli, U. E.

1978-01-01

The effects of cathode material, cathode operating temperature, anode configuration, window materials, and hydrogen additives on laser lifetime are determined. Internally oxidized copper and silber-copper alloy cathodes were tested. The cathode operating temperature was raised in some tubes through the use of thermal insulation. Lasers incorporating thermally insulated silver copper oxide cathodes clearly yielded the longest lifetimes-typically in excess of 22,000 hours. The use of platinum sheet versus platinum pin anodes had no observable effect on laser lifetime. Similarly, the choice of germanium, cadmium telluride, or zinc selenide as the optical window material appears to have no impact on lifetime.

Optical emission of directly contacted copper/sapphire interface under shock compression of megabar

NASA Astrophysics Data System (ADS)

Hao, G. Y.; Liu, F. S.; Zhang, D. Y.; Zhang, M. J.

2007-06-01

The shock-induced optical emission histories from copper/sapphire interface were measured under two different contact conditions, which simulated the typical situations of pyrometry experiments. Results showed that the "peak" feature of the radiation, previously interpreted as the appearance of so-called high-temperature layer, was nearly diminished by finely polishing and uniformly prepressing technique, and that it is possible to directly measure the equilibrium temperature of bulk metal/window interface. Study also demonstrated that the saturated value of the apparent temperature in nonideal contact situation is related to the color temperature of the shock-induced "bright spot" in sapphire window under megabar pressures.

On Time Delay Margin Estimation for Adaptive Control and Optimal Control Modification

NASA Technical Reports Server (NTRS)

Nguyen, Nhan T.

2011-01-01

This paper presents methods for estimating time delay margin for adaptive control of input delay systems with almost linear structured uncertainty. The bounded linear stability analysis method seeks to represent an adaptive law by a locally bounded linear approximation within a small time window. The time delay margin of this input delay system represents a local stability measure and is computed analytically by three methods: Pade approximation, Lyapunov-Krasovskii method, and the matrix measure method. These methods are applied to the standard model-reference adaptive control, s-modification adaptive law, and optimal control modification adaptive law. The windowing analysis results in non-unique estimates of the time delay margin since it is dependent on the length of a time window and parameters which vary from one time window to the next. The optimal control modification adaptive law overcomes this limitation in that, as the adaptive gain tends to infinity and if the matched uncertainty is linear, then the closed-loop input delay system tends to a LTI system. A lower bound of the time delay margin of this system can then be estimated uniquely without the need for the windowing analysis. Simulation results demonstrates the feasibility of the bounded linear stability method for time delay margin estimation.

Introduction and application of the multiscale coefficient of variation analysis.

PubMed

Abney, Drew H; Kello, Christopher T; Balasubramaniam, Ramesh

2017-10-01

Quantifying how patterns of behavior relate across multiple levels of measurement typically requires long time series for reliable parameter estimation. We describe a novel analysis that estimates patterns of variability across multiple scales of analysis suitable for time series of short duration. The multiscale coefficient of variation (MSCV) measures the distance between local coefficient of variation estimates within particular time windows and the overall coefficient of variation across all time samples. We first describe the MSCV analysis and provide an example analytical protocol with corresponding MATLAB implementation and code. Next, we present a simulation study testing the new analysis using time series generated by ARFIMA models that span white noise, short-term and long-term correlations. The MSCV analysis was observed to be sensitive to specific parameters of ARFIMA models varying in the type of temporal structure and time series length. We then apply the MSCV analysis to short time series of speech phrases and musical themes to show commonalities in multiscale structure. The simulation and application studies provide evidence that the MSCV analysis can discriminate between time series varying in multiscale structure and length.

High-Reliability Waveguide Vacuum/Pressure Window

NASA Technical Reports Server (NTRS)

Britcliffe, Michael J.; Hanson, Theodore R.; Long, Ezra M.; Montanez, Steven

2013-01-01

The NASA Deep Space Network (DSN) uses commercial waveguide windows on the output waveguide of Ka-band (32 GHz) low-noise amplifiers. Mechanical failure of these windows resulted in an unacceptable loss in tracking time. To address this issue, a new Ka-band WR-28 waveguide window has been designed, fabricated, and tested. The window uses a slab of low-loss, low-dielectric constant foam that is bonded into a 1/2-wave-thick waveguide/flange. The foam is a commercially available, rigid, closed-cell polymethacrylimide. It has excellent electrical properties with a dielectric constant of 1.04, and a loss tangent of 0.01. It is relatively strong with a tensile strength of 1 MPa. The material is virtually impermeable to helium. The finished window exhibits a leak rate of less than 3x10(exp -3)cu cm/s with helium. The material is also chemically resistant and can be cleaned with acetone. The window is constructed by fabricating a window body by brazing a short length of WR-28 copper waveguide into a standard rectangular flange, and machining the resulting part to a thickness of 4.6 mm. The foam is machined to a rectangular shape with a dimension of 7.06x3.53 mm. The foam is bonded into the body with a two-part epoxy. After curing, the excess glue and foam are knife-trimmed by hand. The finished window has a loss of less than 0.08 dB (2%) and a return loss of greater than 25 dB at 32 GHz. This meets the requirements for the DSN application. The window is usable for most applications over the entire 26-to-40-GHz waveguide band. The window return loss can be tuned to a required frequency by var y in g the thickness of the window slightly. Most standard waveguide windows use a thin membrane of material bonded into a recess in a waveguide flange, or sandwiched between two flanges with a polymer seal. Designs using the recessed window are prone to mechanical failure over time due to constraints on the dimensions of the recess that allow the bond to fail. Designs using the sandwich method are often permeable to helium, which prohibits the use of helium leak detection. At the time of this reporting, 40 windows have been produced. Twelve are in operation with a combined operating time of over 30,000 hours without a failure.

76 FR 23911 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of the Gulf of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-29

... maintenance window for the Gulf individual fishing quota (IFQ) programs, and removing obsolete codified text..., etc.), extends the IFQ maintenance window an additional 8 hours to allow for more time to conduct end... maintenance window. All electronic IFQ transactions must be completed by December 31 at 6 p.m. eastern time...

21. DETAIL OF AREA WHERE FIRST FLOOR PASSAGEWAY USED TO ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

21. DETAIL OF AREA WHERE FIRST FLOOR PASSAGEWAY USED TO BE SHOWING VERTICAL WOOD MOLDING COVERING JOINT WHERE PARTITION USED TO BE (LEFT), TELLER'S WINDOW LINKING PASSAGEWAY WITH INFORMATION BOOTH (CENTER), AND TYPICAL FURNITURE. VIEW TO EAST. - Boise Project, Boise Project Office, 214 Broadway, Boise, Ada County, ID

Research & Action Report. Volume 31, Number 1, Fall/Winter 2009

ERIC Educational Resources Information Center

Mongeon, Rebecca, Ed.; Tambascio, Donna, Ed.

2009-01-01

The "Research & Action Report," published twice a year, is a window on the activities and initiatives at the Wellesley Centers for Women. The report typically features news about the Centers, interviews with researchers, commentary on recent events or social trends affecting women and girls, announcements of new publications, and…

Windows on Achievement and Inequality. Policy Information Report

ERIC Educational Resources Information Center

Barton, Paul E.; Coley, Richard J.

2008-01-01

Shifting focus from typical data and information about the status of educational achievement in the United States and about gaps in achievement among the nation's students, this report undertakes investigation of less-frequently-asked questions. As required by the No Child Left Behind Act (NCLB), educators are continuously monitoring whether more…

Research & Action Report. Volume 32, Number 1, Fall/Winter 2010

ERIC Educational Resources Information Center

Mongeon, Rebecca, Ed.; Tambascio, Donna, Ed.

2010-01-01

The "Research & Action Report," published twice a year, is a window on the activities and initiatives at the Wellesley Centers for Women. The report typically features news about the Centers, interviews with researchers, commentary on recent events or social trends affecting women and girls, announcements of new publications, and…

Research & Action Report. Volume 31, Number 2, Spring/Summer 2010

ERIC Educational Resources Information Center

Mongeon, Rebecca, Ed.; Tambascio, Donna, Ed.

2010-01-01

The "Research & Action Report," published twice a year, is a window on the activities and initiatives at the Wellesley Centers for Women. The report typically features news about the Centers, interviews with researchers, commentary on recent events or social trends affecting women and girls, announcements of new publications, and…

Battery Berry Observation Station, detail of west side showing former ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Battery Berry Observation Station, detail of west side showing former entry recess and typical sash window; view southeast - Fort McKinley, Battery Berry Observation Station, North side of Wood Side Drive approximately 80 feet east of Spring Cove Lane, Great Diamond Island, Portland, Cumberland County, ME

Research & Action Report. Volume 33, Number 1, Fall/Winter 2011

ERIC Educational Resources Information Center

Kellett, Megan, Ed.; Tambascio, Donna, Ed.

2011-01-01

The "Research & Action Report," published twice a year, is a window on the activities and initiatives at the Wellesley Centers for Women. The report typically features news about the Centers, interviews with researchers, commentary on recent events or social trends affecting women and girls, announcements of new publications, and…

Design of high-efficiency diffractive optical elements towards ultrafast mid-infrared time-stretched imaging and spectroscopy

NASA Astrophysics Data System (ADS)

Xie, Hongbo; Ren, Delun; Wang, Chao; Mao, Chensheng; Yang, Lei

2018-02-01

Ultrafast time stretch imaging offers unprecedented imaging speed and enables new discoveries in scientific research and engineering. One challenge in exploiting time stretch imaging in mid-infrared is the lack of high-quality diffractive optical elements (DOEs), which encode the image information into mid-infrared optical spectrum. This work reports the design and optimization of mid-infrared DOE with high diffraction-efficiency, broad bandwidth and large field of view. Using various typical materials with their refractive indices ranging from 1.32 to 4.06 in ? mid-infrared band, diffraction efficiencies of single-layer and double-layer DOEs have been studied in different wavelength bands with different field of views. More importantly, by replacing the air gap of double-layer DOE with carefully selected optical materials, one optimized ? triple-layer DOE, with efficiency higher than 95% in the whole ? mid-infrared window and field of view greater than ?, is designed and analyzed. This new DOE device holds great potential in ultrafast mid-infrared time stretch imaging and spectroscopy.

Apollo - LOLA Project

NASA Image and Video Library

1961-12-05

Project LOLA. Test subject sitting at the controls: Project LOLA or Lunar Orbit and Landing Approach was a simulator built at Langley to study problems related to landing on the lunar surface. It was a complex project that cost nearly 2 million dollars. James Hansen wrote: This simulator was designed to provide a pilot with a detailed visual encounter with the lunar surface the machine consisted primarily of a cockpit, a closed-circuit TV system, and four large murals or scale models representing portions of the lunar surface as seen from various altitudes. The pilot in the cockpit moved along a track past these murals which would accustom him to the visual cues for controlling a spacecraft in the vicinity of the moon. Unfortunately, such a simulation--although great fun and quite aesthetic--was not helpful because flight in lunar orbit posed no special problems other than the rendezvous with the LEM, which the device did not simulate. Not long after the end of Apollo, the expensive machine was dismantled. (p. 379) Ellis J. White wrote in his paper, Discussion of Three Typical Langley Research Center Simulation Programs : A typical mission would start with the first cart positioned on model 1 for the translunar approach and orbit establishment. After starting the descent, the second cart is readied on model 2 and, at the proper time, when superposition occurs, the pilot s scene is switched from model 1 to model 2. then cart 1 is moved to and readied on model 3. The procedure continues until an altitude of 150 feet is obtained. The cabin of the LM vehicle has four windows which represent a 45 degree field of view. The projection screens in front of each window represent 65 degrees which allows limited head motion before the edges of the display can be seen. The lunar scene is presented to the pilot by rear projection on the screens with four Schmidt television projectors. The attitude orientation of the vehicle is represented by changing the lunar scene through the portholes determined by the scan pattern of four orthicons. The stars are front projected onto the upper three screens with a four-axis starfield generation (starball) mounted over the cabin and there is a separate starball for the low window. -- Published in James R. Hansen, Spaceflight Revolution: NASA Langley Research Center From Sputnik to Apollo, (Washington: NASA, 1995), p. 379 Ellis J. White, Discussion of Three Typical Langley Research Center Simulation Programs, Paper presented at the Eastern Simulation Council (EAI s Princeton Computation Center), Princeton, NJ, October 20, 1966.

Self spectrum window method in wigner-ville distribution.

PubMed

Liu, Zhongguo; Liu, Changchun; Liu, Boqiang; Lv, Yangsheng; Lei, Yinsheng; Yu, Mengsun

2005-01-01

Wigner-Ville distribution (WVD) is an important type of time-frequency analysis in biomedical signal processing. The cross-term interference in WVD has a disadvantageous influence on its application. In this research, the Self Spectrum Window (SSW) method was put forward to suppress the cross-term interference, based on the fact that the cross-term and auto-WVD- terms in integral kernel function are orthogonal. With the Self Spectrum Window (SSW) algorithm, a real auto-WVD function was used as a template to cross-correlate with the integral kernel function, and the Short Time Fourier Transform (STFT) spectrum of the signal was used as window function to process the WVD in time-frequency plane. The SSW method was confirmed by computer simulation with good analysis results. Satisfactory time- frequency distribution was obtained.

Fully automatic time-window selection using machine learning for global adjoint tomography

NASA Astrophysics Data System (ADS)

Chen, Y.; Hill, J.; Lei, W.; Lefebvre, M. P.; Bozdag, E.; Komatitsch, D.; Tromp, J.

2017-12-01

Selecting time windows from seismograms such that the synthetic measurements (from simulations) and measured observations are sufficiently close is indispensable in a global adjoint tomography framework. The increasing amount of seismic data collected everyday around the world demands "intelligent" algorithms for seismic window selection. While the traditional FLEXWIN algorithm can be "automatic" to some extent, it still requires both human input and human knowledge or experience, and thus is not deemed to be fully automatic. The goal of intelligent window selection is to automatically select windows based on a learnt engine that is built upon a huge number of existing windows generated through the adjoint tomography project. We have formulated the automatic window selection problem as a classification problem. All possible misfit calculation windows are classified as either usable or unusable. Given a large number of windows with a known selection mode (select or not select), we train a neural network to predict the selection mode of an arbitrary input window. Currently, the five features we extract from the windows are its cross-correlation value, cross-correlation time lag, amplitude ratio between observed and synthetic data, window length, and minimum STA/LTA value. More features can be included in the future. We use these features to characterize each window for training a multilayer perceptron neural network (MPNN). Training the MPNN is equivalent to solve a non-linear optimization problem. We use backward propagation to derive the gradient of the loss function with respect to the weighting matrices and bias vectors and use the mini-batch stochastic gradient method to iteratively optimize the MPNN. Numerical tests show that with a careful selection of the training data and a sufficient amount of training data, we are able to train a robust neural network that is capable of detecting the waveforms in an arbitrary earthquake data with negligible detection error compared to existing selection methods (e.g. FLEXWIN). We will introduce in detail the mathematical formulation of the window-selection-oriented MPNN and show very encouraging results when applying the new algorithm to real earthquake data.

A Frequency-Domain Implementation of a Sliding-Window Traffic Sign Detector for Large Scale Panoramic Datasets

NASA Astrophysics Data System (ADS)

Creusen, I. M.; Hazelhoff, L.; De With, P. H. N.

2013-10-01

In large-scale automatic traffic sign surveying systems, the primary computational effort is concentrated at the traffic sign detection stage. This paper focuses on reducing the computational load of particularly the sliding window object detection algorithm which is employed for traffic sign detection. Sliding-window object detectors often use a linear SVM to classify the features in a window. In this case, the classification can be seen as a convolution of the feature maps with the SVM kernel. It is well known that convolution can be efficiently implemented in the frequency domain, for kernels larger than a certain size. We show that by careful reordering of sliding-window operations, most of the frequency-domain transformations can be eliminated, leading to a substantial increase in efficiency. Additionally, we suggest to use the overlap-add method to keep the memory use within reasonable bounds. This allows us to keep all the transformed kernels in memory, thereby eliminating even more domain transformations, and allows all scales in a multiscale pyramid to be processed using the same set of transformed kernels. For a typical sliding-window implementation, we have found that the detector execution performance improves with a factor of 5.3. As a bonus, many of the detector improvements from literature, e.g. chi-squared kernel approximations, sub-class splitting algorithms etc., can be more easily applied at a lower performance penalty because of an improved scalability.

Intact skull chronic windows for mesoscopic wide-field imaging in awake mice

PubMed Central

Silasi, Gergely; Xiao, Dongsheng; Vanni, Matthieu P.; Chen, Andrew C. N.; Murphy, Timothy H.

2016-01-01

Background Craniotomy-based window implants are commonly used for microscopic imaging, in head-fixed rodents, however their field of view is typically small and incompatible with mesoscopic functional mapping of cortex. New Method We describe a reproducible and simple procedure for chronic through-bone wide-field imaging in awake head-fixed mice providing stable optical access for chronic imaging over large areas of the cortex for months. Results The preparation is produced by applying clear-drying dental cement to the intact mouse skull, followed by a glass coverslip to create a partially transparent imaging surface. Surgery time takes about 30 minutes. A single set-screw provides a stable means of attachment for mesoscale assessment without obscuring the cortical field of view. Comparison with Existing Methods We demonstrate the utility of this method by showing seed-pixel functional connectivity maps generated from spontaneous cortical activity of GCAMP6 signals in both awake and anesthetized mice. Conclusions We propose that the intact skull preparation described here may be used for most longitudinal studies that do not require micron scale resolution and where cortical neural or vascular signals are recorded with intrinsic sensors. PMID:27102043

Tattoos as a window to the psyche: How talking about skin art can inform psychiatric practice.

PubMed

Roggenkamp, Hannah; Nicholls, Andrew; Pierre, Joseph M

2017-09-22

Tattooing the skin as a means of personal expression is a ritualized practice that has been around for centuries across many different cultures. Accordingly, the symbolic meaning of tattoos has evolved over time and is highly individualized, from both the internal perspective of the wearer and the external perspective of an observer. Within modern Western societies through the 1970s, tattoos represented a cultural taboo, typically associated with those outside of the mainstream such as soldiers, incarcerated criminals, gang members, and others belonging to marginalized and counter-cultural groups. This paper aims to review the more recent epidemiology of tattoos in Western culture in order to establish that tattooing has become a mainstream phenomenon. We then review psychological and psychiatric aspects of tattoos, with a goal of revising outmoded stigmas about tattooing and helping clinicians working with tattooed patients to facilitate an exploration of the personal meaning of skin art and self-identity. We suggest that as a kind of augmentation of the physical exam, looking at and talking to patients about their tattoos can provide a valuable window into the psyche, informing clinical practice.

Tattoos as a window to the psyche: How talking about skin art can inform psychiatric practice

PubMed Central

Roggenkamp, Hannah; Nicholls, Andrew; Pierre, Joseph M

2017-01-01

Tattooing the skin as a means of personal expression is a ritualized practice that has been around for centuries across many different cultures. Accordingly, the symbolic meaning of tattoos has evolved over time and is highly individualized, from both the internal perspective of the wearer and the external perspective of an observer. Within modern Western societies through the 1970s, tattoos represented a cultural taboo, typically associated with those outside of the mainstream such as soldiers, incarcerated criminals, gang members, and others belonging to marginalized and counter-cultural groups. This paper aims to review the more recent epidemiology of tattoos in Western culture in order to establish that tattooing has become a mainstream phenomenon. We then review psychological and psychiatric aspects of tattoos, with a goal of revising outmoded stigmas about tattooing and helping clinicians working with tattooed patients to facilitate an exploration of the personal meaning of skin art and self-identity. We suggest that as a kind of augmentation of the physical exam, looking at and talking to patients about their tattoos can provide a valuable window into the psyche, informing clinical practice. PMID:29043152

Robust alignment of chromatograms by statistically analyzing the shifts matrix generated by moving window fast Fourier transform cross-correlation.

PubMed

Zhang, Mingjing; Wen, Ming; Zhang, Zhi-Min; Lu, Hongmei; Liang, Yizeng; Zhan, Dejian

2015-03-01

Retention time shift is one of the most challenging problems during the preprocessing of massive chromatographic datasets. Here, an improved version of the moving window fast Fourier transform cross-correlation algorithm is presented to perform nonlinear and robust alignment of chromatograms by analyzing the shifts matrix generated by moving window procedure. The shifts matrix in retention time can be estimated by fast Fourier transform cross-correlation with a moving window procedure. The refined shift of each scan point can be obtained by calculating the mode of corresponding column of the shifts matrix. This version is simple, but more effective and robust than the previously published moving window fast Fourier transform cross-correlation method. It can handle nonlinear retention time shift robustly if proper window size has been selected. The window size is the only one parameter needed to adjust and optimize. The properties of the proposed method are investigated by comparison with the previous moving window fast Fourier transform cross-correlation and recursive alignment by fast Fourier transform using chromatographic datasets. The pattern recognition results of a gas chromatography mass spectrometry dataset of metabolic syndrome can be improved significantly after preprocessing by this method. Furthermore, the proposed method is available as an open source package at https://github.com/zmzhang/MWFFT2. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Free-breathing 3D Cardiac MRI Using Iterative Image-Based Respiratory Motion Correction

PubMed Central

Moghari, Mehdi H.; Roujol, Sébastien; Chan, Raymond H.; Hong, Susie N.; Bello, Natalie; Henningsson, Markus; Ngo, Long H.; Goddu, Beth; Goepfert, Lois; Kissinger, Kraig V.; Manning, Warren J.; Nezafat, Reza

2012-01-01

Respiratory motion compensation using diaphragmatic navigator (NAV) gating with a 5 mm gating window is conventionally used for free-breathing cardiac MRI. Due to the narrow gating window, scan efficiency is low resulting in long scan times, especially for patients with irregular breathing patterns. In this work, a new retrospective motion compensation algorithm is presented to reduce the scan time for free-breathing cardiac MRI that increasing the gating window to 15 mm without compromising image quality. The proposed algorithm iteratively corrects for respiratory-induced cardiac motion by optimizing the sharpness of the heart. To evaluate this technique, two coronary MRI datasets with 1.3 mm3 resolution were acquired from 11 healthy subjects (7 females, 25±9 years); one using a NAV with a 5 mm gating window acquired in 12.0±2.0 minutes and one with a 15 mm gating window acquired in 7.1±1.0 minutes. The images acquired with a 15 mm gating window were corrected using the proposed algorithm and compared to the uncorrected images acquired with the 5 mm and 15 mm gating windows. The image quality score, sharpness, and length of the three major coronary arteries were equivalent between the corrected images and the images acquired with a 5 mm gating window (p-value>0.05), while the scan time was reduced by a factor of 1.7. PMID:23132549

Damage to urban buildings in zones of intensities VIII and VII during the Wenchuan earthquake and discussion on some typical damages

NASA Astrophysics Data System (ADS)

Sun, Jingjiang; Tang, Yuhong; Zheng, Chao; Shi, Hongbin; Lin, Lin; Sun, Zhongxian

2009-04-01

The outline and typical characteristics of damages to building in Jiangyou city and Anxian county (intensity VIII), Mianyang city and Deyang city (intensity VII) are introduced in the paper. The damage ratios, based on the sample statistics of multi-story brick buildings together with multi-story brick buildings with RC frame at first story (BBF), are presented. Then some typical damages, such as horizontal cricks of brick masonry buildings, X-shaped cricks on the walls under windows, the damages to columns, beams and infill walls of frame buildings and the damage to half circle-shaped masonry walls, are discussed.

Evaluation of optimized magnetic resonance perfusion imaging scanning time window after contrast agent injection for differentiating benign and malignant breast lesions

PubMed Central

Dong, Jie; Wang, Dawei; Ma, Zhenshen; Deng, Guodong; Wang, Lanhua; Zhang, Jiandong

2017-01-01

The aim of the study was evaluate the 3.0 T magnetic resonance (MR) perfusion imaging scanning time window following contrast injection for differentiating benign and malignant breast lesions and to determine the optimum scanning time window for increased scanner usage efficiency and reduced diagnostic adverse risk factors. A total of 52 women with breast abnormalities were selected for conventional MR imaging and T1 dynamic-enhanced imaging. Quantitative parameters [volume transfer constant (Ktrans), rate constant (Kep) and extravascular extracellular volume fraction (Ve)] were calculated at phases 10, 20, 30, 40 and 50, which represented time windows at 5, 10, 15, 20 and 25 min, respectively, following injection of contrast agent. The association of the parameters at different phases with benign and malignant tumor diagnosis was analyzed. MR perfusion imaging was verified as an effective modality in the diagnosis of breast malignancies and the best scanning time window was identified: i) Values of Ktrans and Kep at all phases were statistically significant in differentiating benign and malignant tumors (P<0.05), while the value of Ve had statistical significance only at stage 10, but not at any other stages (P>0.05); ii) values of Ve in benign tumors increased with phase number, but achieved no obvious changes at different phases in malignant tumors; iii) the optimum scanning time window of breast perfusion imaging with 3.0 T MR was between phases 10 and 30 (i.e., between 5 and 15 min after contrast agent injection). The variation trend of Ve values at different phases may serve as a diagnostic reference for differentiating benign and malignant breast abnormalities. The most efficient scanning time window was indicated to be 5 min after contrast injection, based on the observation that the Ve value only had statistical significance in diagnosis at stage 10. However, the optimal scanning time window is from 5 to 15 min following the injection of contrast agent, since that the variation trend of Ve is able to serve as a diagnostic reference. PMID:28450944

Evaluation of optimized magnetic resonance perfusion imaging scanning time window after contrast agent injection for differentiating benign and malignant breast lesions.

PubMed

Dong, Jie; Wang, Dawei; Ma, Zhenshen; Deng, Guodong; Wang, Lanhua; Zhang, Jiandong

2017-03-01

The aim of the study was evaluate the 3.0 T magnetic resonance (MR) perfusion imaging scanning time window following contrast injection for differentiating benign and malignant breast lesions and to determine the optimum scanning time window for increased scanner usage efficiency and reduced diagnostic adverse risk factors. A total of 52 women with breast abnormalities were selected for conventional MR imaging and T1 dynamic-enhanced imaging. Quantitative parameters [volume transfer constant (K trans ), rate constant (K ep ) and extravascular extracellular volume fraction (V e )] were calculated at phases 10, 20, 30, 40 and 50, which represented time windows at 5, 10, 15, 20 and 25 min, respectively, following injection of contrast agent. The association of the parameters at different phases with benign and malignant tumor diagnosis was analyzed. MR perfusion imaging was verified as an effective modality in the diagnosis of breast malignancies and the best scanning time window was identified: i) Values of K trans and K ep at all phases were statistically significant in differentiating benign and malignant tumors (P<0.05), while the value of V e had statistical significance only at stage 10, but not at any other stages (P>0.05); ii) values of V e in benign tumors increased with phase number, but achieved no obvious changes at different phases in malignant tumors; iii) the optimum scanning time window of breast perfusion imaging with 3.0 T MR was between phases 10 and 30 (i.e., between 5 and 15 min after contrast agent injection). The variation trend of V e values at different phases may serve as a diagnostic reference for differentiating benign and malignant breast abnormalities. The most efficient scanning time window was indicated to be 5 min after contrast injection, based on the observation that the V e value only had statistical significance in diagnosis at stage 10. However, the optimal scanning time window is from 5 to 15 min following the injection of contrast agent, since that the variation trend of V e is able to serve as a diagnostic reference.

Timing anthropogenic stressors to mitigate their impact on marine ecosystem resilience.

PubMed

Wu, Paul Pao-Yen; Mengersen, Kerrie; McMahon, Kathryn; Kendrick, Gary A; Chartrand, Kathryn; York, Paul H; Rasheed, Michael A; Caley, M Julian

2017-11-02

Better mitigation of anthropogenic stressors on marine ecosystems is urgently needed to address increasing biodiversity losses worldwide. We explore opportunities for stressor mitigation using whole-of-systems modelling of ecological resilience, accounting for complex interactions between stressors, their timing and duration, background environmental conditions and biological processes. We then search for ecological windows, times when stressors minimally impact ecological resilience, defined here as risk, recovery and resistance. We show for 28 globally distributed seagrass meadows that stressor scheduling that exploits ecological windows for dredging campaigns can achieve up to a fourfold reduction in recovery time and 35% reduction in extinction risk. Although the timing and length of windows vary among sites to some degree, global trends indicate favourable windows in autumn and winter. Our results demonstrate that resilience is dynamic with respect to space, time and stressors, varying most strongly with: (i) the life history of the seagrass genus and (ii) the duration and timing of the impacting stress.

Platform for Postprocessing Waveform-Based NDE

NASA Technical Reports Server (NTRS)

Roth, Don

2008-01-01

Taking advantage of the similarities that exist among all waveform-based non-destructive evaluation (NDE) methods, a common software platform has been developed containing multiple- signal and image-processing techniques for waveforms and images. The NASA NDE Signal and Image Processing software has been developed using the latest versions of LabVIEW, and its associated Advanced Signal Processing and Vision Toolkits. The software is useable on a PC with Windows XP and Windows Vista. The software has been designed with a commercial grade interface in which two main windows, Waveform Window and Image Window, are displayed if the user chooses a waveform file to display. Within these two main windows, most actions are chosen through logically conceived run-time menus. The Waveform Window has plots for both the raw time-domain waves and their frequency- domain transformations (fast Fourier transform and power spectral density). The Image Window shows the C-scan image formed from information of the time-domain waveform (such as peak amplitude) or its frequency-domain transformation at each scan location. The user also has the ability to open an image, or series of images, or a simple set of X-Y paired data set in text format. Each of the Waveform and Image Windows contains menus from which to perform many user actions. An option exists to use raw waves obtained directly from scan, or waves after deconvolution if system wave response is provided. Two types of deconvolution, time-based subtraction or inverse-filter, can be performed to arrive at a deconvolved wave set. Additionally, the menu on the Waveform Window allows preprocessing of waveforms prior to image formation, scaling and display of waveforms, formation of different types of images (including non-standard types such as velocity), gating of portions of waves prior to image formation, and several other miscellaneous and specialized operations. The menu available on the Image Window allows many further image processing and analysis operations, some of which are found in commercially-available image-processing software programs (such as Adobe Photoshop), and some that are not (removing outliers, Bscan information, region-of-interest analysis, line profiles, and precision feature measurements).

Adjusting the fairshare policy to prevent computing power loss

NASA Astrophysics Data System (ADS)

Dal Pra, Stefano

2017-10-01

On a typical WLCG site providing batch access to computing resources according to a fairshare policy, the idle time lapse after a job ends and before a new one begins on a given slot is negligible if compared to the duration of typical jobs. The overall amount of these intervals over a time window increases with the size of the cluster and the inverse of job duration and can be considered equivalent to an average number of unavailable slots over that time window. This value has been investigated for the Tier-1 at CNAF, and observed to occasionally grow and reach up to more than the 10% of the about 20,000 available computing slots. Analysis reveals that this happens when a sustained rate of short jobs is submitted to the cluster and dispatched by the batch system. Because of how the default fairshare policy works, it increases the dynamic priority of those users mostly submitting short jobs, since they are not accumulating runtime, and will dispatch more of their jobs at the next round, thus worsening the situation until the submission flow ends. To address this problem the default behaviour of the fairshare have been altered by adding a correcting term to the default formula for the dynamic priority. The LSF batch system, currently adopted at CNAF, provides a way to define its value by invoking a C function, which returns it for each user in the cluster. The correcting term works by rounding up to a minimum defined runtime the most recently done jobs. Doing so, each short job looks almost like a regular one and the dynamic priority value settles to a proper value. The net effect is a reduction of the dispatching rate of short jobs and, consequently, the average number of available slots greatly improves. Furthermore, a potential starvation problem, actually observed at least once is also prevented. After describing short jobs and reporting about their impact on the cluster, possible workarounds are discussed and the selected solution is motivated. Details on the most critical aspects of the implementation are explained and the observed results are presented.

75 FR 74687 - Takes of Marine Mammals Incidental to Specified Activities; Construction of the Parsons Slough...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-01

.... Actual pile driving time during this work window will depend on a number of factors, such as sediments... period beginning in November 2010, and ending in February 2011. This work window was selected to coincide.... The work window also coincides with the USFWS' required construction work window to avoid the peak...

A Window-Washing Challenge

ERIC Educational Resources Information Center

Roman, Harry T.

2010-01-01

Skyscrapers sure do have a lot of windows, and these windows are cleaned and checked regularly. All this takes time, money, and puts workers at potential risk. Might there be a better way to do it? In this article, the author discusses a window-washing challenge and describes how students can tackle this task, pick up the challenge, and creatively…

Design and implementation of laser target simulator in hardware-in-the-loop simulation system based on LabWindows/CVI and RTX

NASA Astrophysics Data System (ADS)

Tong, Qiujie; Wang, Qianqian; Li, Xiaoyang; Shan, Bin; Cui, Xuntai; Li, Chenyu; Peng, Zhong

2016-11-01

In order to satisfy the requirements of the real-time and generality, a laser target simulator in semi-physical simulation system based on RTX+LabWindows/CVI platform is proposed in this paper. Compared with the upper-lower computers simulation platform architecture used in the most of the real-time system now, this system has better maintainability and portability. This system runs on the Windows platform, using Windows RTX real-time extension subsystem to ensure the real-time performance of the system combining with the reflective memory network to complete some real-time tasks such as calculating the simulation model, transmitting the simulation data, and keeping real-time communication. The real-time tasks of simulation system run under the RTSS process. At the same time, we use the LabWindows/CVI to compile a graphical interface, and complete some non-real-time tasks in the process of simulation such as man-machine interaction, display and storage of the simulation data, which run under the Win32 process. Through the design of RTX shared memory and task scheduling algorithm, the data interaction between the real-time tasks process of RTSS and non-real-time tasks process of Win32 is completed. The experimental results show that this system has the strongly real-time performance, highly stability, and highly simulation accuracy. At the same time, it also has the good performance of human-computer interaction.

Rapidity window dependences of higher order cumulants and diffusion master equation

NASA Astrophysics Data System (ADS)

Kitazawa, Masakiyo

2015-10-01

We study the rapidity window dependences of higher order cumulants of conserved charges observed in relativistic heavy ion collisions. The time evolution and the rapidity window dependence of the non-Gaussian fluctuations are described by the diffusion master equation. Analytic formulas for the time evolution of cumulants in a rapidity window are obtained for arbitrary initial conditions. We discuss that the rapidity window dependences of the non-Gaussian cumulants have characteristic structures reflecting the non-equilibrium property of fluctuations, which can be observed in relativistic heavy ion collisions with the present detectors. It is argued that various information on the thermal and transport properties of the hot medium can be revealed experimentally by the study of the rapidity window dependences, especially by the combined use, of the higher order cumulants. Formulas of higher order cumulants for a probability distribution composed of sub-probabilities, which are useful for various studies of non-Gaussian cumulants, are also presented.

Language Development in the First Year of Life: What Deaf Children Might Be Missing Before Cochlear Implantation.

PubMed

Levine, Dani; Strother-Garcia, Kristina; Golinkoff, Roberta Michnick; Hirsh-Pasek, Kathy

2016-02-01

Language development is a multifaceted, dynamic process involving the discovery of complex patterns, and the refinement of native language competencies in the context of communicative interactions. This process is already advanced by the end of the first year of life for hearing children, but prelingually deaf children who initially lack a language model may miss critical experiences during this early window. The purpose of this review is twofold. First, we examine the published literature on language development during the first 12 months in typically developing children. Second, we use this literature to inform our understanding of the language outcomes of prelingually deaf children who receive cochlear implants (CIs), and therefore language input, either before or after the first year. During the first 12 months, typically developing infants exhibit advances in speech segmentation, word learning, syntax acquisition, and communication, both verbal and nonverbal. Infants and their caregivers coconstruct a communication foundation during this time, supporting continued language growth. The language outcomes of hearing children are robustly predicted by their experiences and acquired competencies during the first year; yet these predictive links are absent among prelingually deaf infants lacking a language model (i.e., those without exposure to sign). For deaf infants who receive a CI, implantation timing is crucial. Children receiving CIs before 12 months frequently catch up with their typically developing peers, whereas those receiving CIs later do not. Explanations for the language difficulties of late-implanted children are discussed.

Three-factor models versus time series models: quantifying time-dependencies of interactions between stimuli in cell biology and psychobiology for short longitudinal data.

PubMed

Frank, Till D; Kiyatkin, Anatoly; Cheong, Alex; Kholodenko, Boris N

2017-06-01

Signal integration determines cell fate on the cellular level, affects cognitive processes and affective responses on the behavioural level, and is likely to be involved in psychoneurobiological processes underlying mood disorders. Interactions between stimuli may subjected to time effects. Time-dependencies of interactions between stimuli typically lead to complex cell responses and complex responses on the behavioural level. We show that both three-factor models and time series models can be used to uncover such time-dependencies. However, we argue that for short longitudinal data the three factor modelling approach is more suitable. In order to illustrate both approaches, we re-analysed previously published short longitudinal data sets. We found that in human embryonic kidney 293 cells cells the interaction effect in the regulation of extracellular signal-regulated kinase (ERK) 1 signalling activation by insulin and epidermal growth factor is subjected to a time effect and dramatically decays at peak values of ERK activation. In contrast, we found that the interaction effect induced by hypoxia and tumour necrosis factor-alpha for the transcriptional activity of the human cyclo-oxygenase-2 promoter in HEK293 cells is time invariant at least in the first 12-h time window after stimulation. Furthermore, we applied the three-factor model to previously reported animal studies. In these studies, memory storage was found to be subjected to an interaction effect of the beta-adrenoceptor agonist clenbuterol and certain antagonists acting on the alpha-1-adrenoceptor / glucocorticoid-receptor system. Our model-based analysis suggests that only if the antagonist drug is administer in a critical time window, then the interaction effect is relevant. © The authors 2016. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

Compound windows of the Hénon-map

NASA Astrophysics Data System (ADS)

Lorenz, Edward N.

2008-08-01

For the two-parameter second-order Hénon map, the shapes and locations of the periodic windows-continua of parameter values for which solutions x0,x1,… can be stably periodic, embedded in larger regions where chaotic solutions or solutions of other periods prevail-are found by a random searching procedure and displayed graphically. Many windows have a typical shape, consisting of a central “body” from which four narrow “antennae” extend. Such windows, to be called compound windows, are often arranged in bands, to be called window streets, that are made up largely of small detected but poorly resolved compound windows. For each fundamental subwindow-the portion of a window where a fundamental period prevails-a stability measure U is introduced; where the solution is stable, |U|<1. Curves of constant U are found by numerical integration. Along one line in parameter space the Hénon-map reduces to the one-parameter first-order logistic map, and two antennae from each compound window intersect this line. The curves where U=1 and U=-1 that bound either antenna are close together within these intersections, but, as either curve with U=-1 leaves the line, it diverges from the curve where U=1, crosses the other curve where U=-1, and nears the other curve where U=1, forming another antenna. The region bounded by the numerically determined curves coincides with the subwindow as found by random searching. A fourth-degree equation for an idealized curve of constant U is established. Points in parameter space producing periodic solutions where x0=xm=0, for given values of m, are found to lie on Cantor sets of curves that closely fit the window streets. Points producing solutions where x0=xm=0 and satisfying a third condition, approximating the condition that xn be bounded as n→-∞, lie on curves, to be called street curves of order m, that approximate individual members of the Cantor set and individual window streets. Compound windows of period m+m‧ tend to occur near the intersections of street curves of orders m and m‧. Some exceptions to what appear to be fairly general results are noted. The exceptions render it difficult to establish general theorems.

Optimization of ramp area aircraft push back time windows in the presence of uncertainty

NASA Astrophysics Data System (ADS)

Coupe, William Jeremy

It is well known that airport surface traffic congestion at major airports is responsible for increased taxi-out times, fuel burn and excess emissions and there is potential to mitigate these negative consequences through optimizing airport surface traffic operations. Due to a highly congested voice communication channel between pilots and air traffic controllers and a data communication channel that is used only for limited functions, one of the most viable near-term strategies for improvement of the surface traffic is issuing a push back advisory to each departing aircraft. This dissertation focuses on the optimization of a push back time window for each departing aircraft. The optimization takes into account both spatial and temporal uncertainties of ramp area aircraft trajectories. The uncertainties are described by a stochastic kinematic model of aircraft trajectories, which is used to infer distributions of combinations of push back times that lead to conflict among trajectories from different gates. The model is validated and the distributions are included in the push back time window optimization. Under the assumption of a fixed taxiway spot schedule, the computed push back time windows can be integrated with a higher level taxiway scheduler to optimize the flow of traffic from the gate to the departure runway queue. To enable real-time decision making the computational time of the push back time window optimization is critical and is analyzed throughout.

Impact of Hypokalemia on Electromechanical Window, Excitation Wavelength and Repolarization Gradients in Guinea-Pig and Rabbit Hearts

PubMed Central

Osadchii, Oleg E.

2014-01-01

Normal hearts exhibit a positive time difference between the end of ventricular contraction and the end of QT interval, which is referred to as the electromechanical (EM) window. Drug-induced prolongation of repolarization may lead to the negative EM window, which was proposed to be a novel proarrhythmic marker. This study examined whether abnormal changes in the EM window may account for arrhythmogenic effects produced by hypokalemia. Left ventricular pressure, electrocardiogram, and epicardial monophasic action potentials were recorded in perfused hearts from guinea-pig and rabbit. Hypokalemia (2.5 mM K+) was found to prolong repolarization, reduce the EM window, and promote tachyarrhythmia. Nevertheless, during both regular pacing and extrasystolic excitation, the increased QT interval invariably remained shorter than the duration of mechanical systole, thus yielding positive EM window values. Hypokalemia-induced arrhythmogenicity was associated with slowed ventricular conduction, and shortened effective refractory periods, which translated to a reduced excitation wavelength index. Hypokalemia also evoked non-uniform prolongation of action potential duration in distinct epicardial regions, which resulted in increased spatial variability in the repolarization time. These findings suggest that arrhythmogenic effects of hypokalemia are not accounted for by the negative EM window, and are rather attributed to abnormal changes in ventricular conduction times, refractoriness, excitation wavelength, and spatial repolarization gradients. PMID:25141124

Evaluation of Building Energy Saving Through the Development of Venetian Blinds' Optimal Control Algorithm According to the Orientation and Window-to-Wall Ratio

NASA Astrophysics Data System (ADS)

Kwon, Hyuk Ju; Yeon, Sang Hun; Lee, Keum Ho; Lee, Kwang Ho

2018-02-01

As various studies focusing on building energy saving have been continuously conducted, studies utilizing renewable energy sources, instead of fossil fuel, are needed. In particular, studies regarding solar energy are being carried out in the field of building science; in order to utilize such solar energy effectively, solar radiation being brought into the indoors should be acquired and blocked properly. Blinds are a typical solar radiation control device that is capable of controlling indoor thermal and light environments. However, slat-type blinds are manually controlled, giving a negative effect on building energy saving. In this regard, studies regarding the automatic control of slat-type blinds have been carried out for the last couple of decades. Therefore, this study aims to provide preliminary data for optimal control research through the controlling of slat angle in slat-type blinds by comprehensively considering various input variables. The window area ratio and orientation were selected as input variables. It was found that an optimal control algorithm was different among each window-to-wall ratio and window orientation. In addition, through comparing and analyzing the building energy saving performance for each condition by applying the developed algorithms to simulations, up to 20.7 % energy saving was shown in the cooling period and up to 12.3 % energy saving was shown in the heating period. In addition, building energy saving effect was greater as the window area ratio increased given the same orientation, and the effects of window-to-wall ratio in the cooling period were higher than those of window-to-wall ratio in the heating period.

Study of Einstein-Podolsky-Rosen state for space-time variables in a two photon interference experiment

NASA Technical Reports Server (NTRS)

Shih, Y. H.; Sergienko, A. V.; Rubin, M. H.

1993-01-01

A pair of correlated photons generated from parametric down conversion was sent to two independent Michelson interferometers. Second order interference was studied by means of a coincidence measurement between the outputs of two interferometers. The reported experiment and analysis studied this second order interference phenomena from the point of view of Einstein-Podolsky-Rosen paradox. The experiment was done in two steps. The first step of the experiment used 50 psec and 3 nsec coincidence time windows simultaneously. The 50 psec window was able to distinguish a 1.5 cm optical path difference in the interferometers. The interference visibility was measured to be 38 percent and 21 percent for the 50 psec time window and 22 percent and 7 percent for the 3 nsec time window, when the optical path difference of the interferometers were 2 cm and 4 cm, respectively. By comparing the visibilities between these two windows, the experiment showed the non-classical effect which resulted from an E.P.R. state. The second step of the experiment used a 20 psec coincidence time window, which was able to distinguish a 6 mm optical path difference in the interferometers. The interference visibilities were measured to be 59 percent for an optical path difference of 7 mm. This is the first observation of visibility greater than 50 percent for a two interferometer E.P.R. experiment which demonstrates nonclassical correlation of space-time variables.

STS-84 Atlantis on Pad 39-A after RSS roll back

NASA Technical Reports Server (NTRS)

1997-01-01

News media representatives watch and record as the Space Shuttle Atlantis in full launch configuration is revealed after the Rotating Service Structure (RSS) is rotated back at Launch Pad 39A. Rollback of the RSS is a major preflight milestone, typically occurring during the T-11-hour hold on L-1 (the day before launch). Atlantis and its crew of seven are in final preparations for liftoff on Mission STS-84, the sixth of nine planned dockings of the Space Shuttle with the Russian Space Station Mir. Launch is scheduled at about 4:08 a.m. during an approximately 7-minute launch window. The exact liftoff time will be determined about 90 minutes prior to launch, based on the most current location of Mir.

Large deviation probabilities for correlated Gaussian stochastic processes and daily temperature anomalies

NASA Astrophysics Data System (ADS)

Massah, Mozhdeh; Kantz, Holger

2016-04-01

As we have one and only one earth and no replicas, climate characteristics are usually computed as time averages from a single time series. For understanding climate variability, it is essential to understand how close a single time average will typically be to an ensemble average. To answer this question, we study large deviation probabilities (LDP) of stochastic processes and characterize them by their dependence on the time window. In contrast to iid variables for which there exists an analytical expression for the rate function, the correlated variables such as auto-regressive (short memory) and auto-regressive fractionally integrated moving average (long memory) processes, have not an analytical LDP. We study LDP for these processes, in order to see how correlation affects this probability in comparison to iid data. Although short range correlations lead to a simple correction of sample size, long range correlations lead to a sub-exponential decay of LDP and hence to a very slow convergence of time averages. This effect is demonstrated for a 120 year long time series of daily temperature anomalies measured in Potsdam (Germany).

A scan statistic for identifying optimal risk windows in vaccine safety studies using self-controlled case series design.

PubMed

Xu, Stanley; Hambidge, Simon J; McClure, David L; Daley, Matthew F; Glanz, Jason M

2013-08-30

In the examination of the association between vaccines and rare adverse events after vaccination in postlicensure observational studies, it is challenging to define appropriate risk windows because prelicensure RCTs provide little insight on the timing of specific adverse events. Past vaccine safety studies have often used prespecified risk windows based on prior publications, biological understanding of the vaccine, and expert opinion. Recently, a data-driven approach was developed to identify appropriate risk windows for vaccine safety studies that use the self-controlled case series design. This approach employs both the maximum incidence rate ratio and the linear relation between the estimated incidence rate ratio and the inverse of average person time at risk, given a specified risk window. In this paper, we present a scan statistic that can identify appropriate risk windows in vaccine safety studies using the self-controlled case series design while taking into account the dependence of time intervals within an individual and while adjusting for time-varying covariates such as age and seasonality. This approach uses the maximum likelihood ratio test based on fixed-effects models, which has been used for analyzing data from self-controlled case series design in addition to conditional Poisson models. Copyright © 2013 John Wiley & Sons, Ltd.

The assessment and evaluation of low-frequency noise near the region of infrasound.

PubMed

Ziaran, Stanislav

2014-01-01

The main aim of this paper is to present recent knowledge about the assessment and evaluation of low-frequency sounds (noise) and infrasound, close to the threshold of hearing, and identify their potential effect on human health and annoyance. Low-frequency noise generated by air flowing over a moving car with an open window was chosen as a typical scenario which can be subjectively assessed by people traveling by automobile. The principle of noise generated within the interior of the car and its effects on the comfort of the driver and passengers are analyzed at different velocities. An open window of a car at high velocity behaves as a source of specifically strong tonal low-frequency noise which is generally perceived as annoying. The interior noise generated by an open window of a passenger car was measured under different conditions: Driving on a highway and driving on a typical roadway. First, an octave-band analysis was used to assess the noise level and its impact on the driver's comfort. Second, a fast Fourier transform (FFT) analysis and one-third octave-band analysis were used for the detection of tonal low-frequency noise. Comparison between two different car makers was also done. Finally, the paper suggests some possibilities for scientifically assessing and evaluating low-frequency sounds in general, and some recommendations are introduced for scientific discussion, since sounds with strong low-frequency content (but not only strong) engender greater annoyance than is predicted by an A-weighted sound pressure level.

Bayesian distributed lag interaction models to identify perinatal windows of vulnerability in children's health.

PubMed

Wilson, Ander; Chiu, Yueh-Hsiu Mathilda; Hsu, Hsiao-Hsien Leon; Wright, Robert O; Wright, Rosalind J; Coull, Brent A

2017-07-01

Epidemiological research supports an association between maternal exposure to air pollution during pregnancy and adverse children's health outcomes. Advances in exposure assessment and statistics allow for estimation of both critical windows of vulnerability and exposure effect heterogeneity. Simultaneous estimation of windows of vulnerability and effect heterogeneity can be accomplished by fitting a distributed lag model (DLM) stratified by subgroup. However, this can provide an incomplete picture of how effects vary across subgroups because it does not allow for subgroups to have the same window but different within-window effects or to have different windows but the same within-window effect. Because the timing of some developmental processes are common across subpopulations of infants while for others the timing differs across subgroups, both scenarios are important to consider when evaluating health risks of prenatal exposures. We propose a new approach that partitions the DLM into a constrained functional predictor that estimates windows of vulnerability and a scalar effect representing the within-window effect directly. The proposed method allows for heterogeneity in only the window, only the within-window effect, or both. In a simulation study we show that a model assuming a shared component across groups results in lower bias and mean squared error for the estimated windows and effects when that component is in fact constant across groups. We apply the proposed method to estimate windows of vulnerability in the association between prenatal exposures to fine particulate matter and each of birth weight and asthma incidence, and estimate how these associations vary by sex and maternal obesity status in a Boston-area prospective pre-birth cohort study. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Research & Action Report. Volume 26, Number 1, Fall/Winter 2004

ERIC Educational Resources Information Center

Bailey, Susan McGee, Ed.; Wennemer, Jodie, Ed.

2004-01-01

The "Research & Action Report," published twice a year, is a window on the activities and initiatives at the Wellesley Centers for Women. The report typically features news about the Centers, interviews with researchers, commentary on recent events or social trends affecting women and girls, announcements of new publications, and much more.…

Research & Action Report. Volume 34, Number 1, Fall/Winter 2012

ERIC Educational Resources Information Center

Kellett, Megan, Ed.; Tambascio, Donna, Ed.

2012-01-01

The "Research & Action Report," published twice a year, is a window on the activities and initiatives at the Wellesley Centers for Women. The report typically features news about the Centers, interviews with researchers, commentary on recent events or social trends affecting women and girls, announcements of new publications, and much more.…

Research & Action Report. Volume 29, Number 2, Spring/Summer 2008

ERIC Educational Resources Information Center

Mongeon, Rebecca, Ed.; Tambascio, Donna, Ed.

2008-01-01

The "Research & Action Report," published twice a year, is a window on the activities and initiatives at the Wellesley Centers for Women. The report typically features news about the Centers, interviews with researchers, commentary on recent events or social trends affecting women and girls, announcements of new publications, and much more.…

Development of an EMCCD for lidar applications

NASA Astrophysics Data System (ADS)

De Monte, B.; Bell, R. T.

2017-11-01

A novel detector, incorporating e2v's L3 CCD (L3Vision™) [1] technology for use in LIDAR (Light Detection And Ranging) applications has been designed, manufactured and characterised. The most critical performance aspect was the requirement to collect charge from a 120μm square detection area for a 667ns temporal sampling window, with low crosstalk between successive samples, followed by signal readout with sub-electron effective noise. Additional requirements included low dark signal, high quantum efficiency at the 355nm laser wavelength and the ability to handle bright laser echoes, without corruption of the much fainter useful signals. The detector architecture used high speed charge binning to combine signal from each sampling window into a single charge packet. This was then passed through a multiplication register (Electron Multiplying Charge Coupled Device) operating with a typical gain of 100X to a conventional charge detection circuit. The detector achieved a typical quantum efficiency of 80% and a total noise in darkness of < 0.5 electrons rms. Development of the detector was supported by ESA (European Space Agency).

Measurements of vector fields with diode array

NASA Technical Reports Server (NTRS)

Wiehr, E. J.; Scholiers, W.

1985-01-01

A polarimeter was designed for high spatial and spectral resolution. It consists of a quarter-wave plate alternately operating in two positions for Stoke-V measurements and an additional quarter-wave plate for Stokes-U and -Q measurements. The spatial range covers 75 arcsec, the spectral window of about 1.8 a allows the simultaneous observations of neighboring lines. The block diagram of the data processing and acquisition system consists of five memories each one having a capacity of 10 to the 4th power 16-bit words. The total time to acquire profiles of Stokes parameters can be chosen by selecting the number of successive measurements added in the memories, each individual measurement corresponding to an integration time of 0.5 sec. Typical values range between 2 and 60 sec depending on the brightness of the structure, the amount of polarization and a compromise between desired signal-to-noise ratio and spatial resolution.

Rectified directional sensing in long-range cell migration

PubMed Central

Nakajima, Akihiko; Ishihara, Shuji; Imoto, Daisuke; Sawai, Satoshi

2014-01-01

How spatial and temporal information are integrated to determine the direction of cell migration remains poorly understood. Here, by precise microfluidics emulation of dynamic chemoattractant waves, we demonstrate that, in Dictyostelium, directional movement as well as activation of small guanosine triphosphatase Ras at the leading edge is suppressed when the chemoattractant concentration is decreasing over time. This ‘rectification’ of directional sensing occurs only at an intermediate range of wave speed and does not require phosphoinositide-3-kinase or F-actin. From modelling analysis, we show that rectification arises naturally in a single-layered incoherent feedforward circuit with zero-order ultrasensitivity. The required stimulus time-window predicts ~5 s transient for directional sensing response close to Ras activation and inhibitor diffusion typical for protein in the cytosol. We suggest that the ability of Dictyostelium cells to move only in the wavefront is closely associated with rectification of adaptive response combined with local activation and global inhibition. PMID:25373620

Optimization of finite difference forward modeling for elastic waves based on optimum combined window functions

NASA Astrophysics Data System (ADS)

Jian, Wang; Xiaohong, Meng; Hong, Liu; Wanqiu, Zheng; Yaning, Liu; Sheng, Gui; Zhiyang, Wang

2017-03-01

Full waveform inversion and reverse time migration are active research areas for seismic exploration. Forward modeling in the time domain determines the precision of the results, and numerical solutions of finite difference have been widely adopted as an important mathematical tool for forward modeling. In this article, the optimum combined of window functions was designed based on the finite difference operator using a truncated approximation of the spatial convolution series in pseudo-spectrum space, to normalize the outcomes of existing window functions for different orders. The proposed combined window functions not only inherit the characteristics of the various window functions, to provide better truncation results, but also control the truncation error of the finite difference operator manually and visually by adjusting the combinations and analyzing the characteristics of the main and side lobes of the amplitude response. Error level and elastic forward modeling under the proposed combined system were compared with outcomes from conventional window functions and modified binomial windows. Numerical dispersion is significantly suppressed, which is compared with modified binomial window function finite-difference and conventional finite-difference. Numerical simulation verifies the reliability of the proposed method.

Wrap-Around Out-the-Window Sensor Fusion System

NASA Technical Reports Server (NTRS)

Fox, Jeffrey; Boe, Eric A.; Delgado, Francisco; Secor, James B.; Clark, Michael R.; Ehlinger, Kevin D.; Abernathy, Michael F.

2009-01-01

The Advanced Cockpit Evaluation System (ACES) includes communication, computing, and display subsystems, mounted in a van, that synthesize out-the-window views to approximate the views of the outside world as it would be seen from the cockpit of a crewed spacecraft, aircraft, or remote control of a ground vehicle or UAV (unmanned aerial vehicle). The system includes five flat-panel display units arranged approximately in a semicircle around an operator, like cockpit windows. The scene displayed on each panel represents the view through the corresponding cockpit window. Each display unit is driven by a personal computer equipped with a video-capture card that accepts live input from any of a variety of sensors (typically, visible and/or infrared video cameras). Software running in the computers blends the live video images with synthetic images that could be generated, for example, from heads-up-display outputs, waypoints, corridors, or from satellite photographs of the same geographic region. Data from a Global Positioning System receiver and an inertial navigation system aboard the remote vehicle are used by the ACES software to keep the synthetic and live views in registration. If the live image were to fail, the synthetic scenes could still be displayed to maintain situational awareness.

Alternative Fuels Data Center: Hydrogen Drive

Science.gov Websites

, contact Greater Washington Region Clean Cities Coalition. Download QuickTime Video QuickTime (.mov ) Download Windows Media Video Windows Media (.wmv) Video Download Help Text version See more videos provided

PM2.5-bound metal metabolic distribution and coupled lipid abnormality at different developmental windows.

PubMed

Ku, Tingting; Zhang, Yingying; Ji, Xiaotong; Li, Guangke; Sang, Nan

2017-09-01

Atmospheric fine particulate matter (PM 2.5 ) is a serious threat to human health. As a toxicant constituent, metal leads to significant health risks in a population, but exposure to PM 2.5 -bound metals and their biological impacts are not fully understood. In this study, we determined the metal contents of PM 2.5 samples collected from a typical coal-burning city and then investigated the metabolic distributions of six metals (Zn, Pb, Mn, As, Cu, and Cd) following PM 2.5 inhalation in mice in different developmental windows. The results indicate that fine particles were mainly deposited in the lung, but PM 2.5 -bound metals could reach and gather in secondary off-target tissues (the lung, liver, heart and brain) with a developmental window-dependent property. Furthermore, elevations in triglycerides and cholesterol levels in sensitive developmental windows (the young and elderly stages) occurred, and significant associations between metals (Pb, Mn, As and Cd) and cholesterol in the heart, brain, liver and lung were observed. These findings suggest that PM 2.5 inhalation caused selective metal metabolic distribution in tissues with a developmental window-dependent property and that the effects were associated with lipid alterations. This provides a foundation for the underlying systemic toxicity following PM 2.5 exposure based on metal components. Copyright © 2017 Elsevier Ltd. All rights reserved.

On the relationship between instantaneous phase synchrony and correlation-based sliding windows for time-resolved fMRI connectivity analysis.

PubMed

Pedersen, Mangor; Omidvarnia, Amir; Zalesky, Andrew; Jackson, Graeme D

2018-06-08

Correlation-based sliding window analysis (CSWA) is the most commonly used method to estimate time-resolved functional MRI (fMRI) connectivity. However, instantaneous phase synchrony analysis (IPSA) is gaining popularity mainly because it offers single time-point resolution of time-resolved fMRI connectivity. We aim to provide a systematic comparison between these two approaches, on both temporal and topological levels. For this purpose, we used resting-state fMRI data from two separate cohorts with different temporal resolutions (45 healthy subjects from Human Connectome Project fMRI data with repetition time of 0.72 s and 25 healthy subjects from a separate validation fMRI dataset with a repetition time of 3 s). For time-resolved functional connectivity analysis, we calculated tapered CSWA over a wide range of different window lengths that were temporally and topologically compared to IPSA. We found a strong association in connectivity dynamics between IPSA and CSWA when considering the absolute values of CSWA. The association between CSWA and IPSA was stronger for a window length of ∼20 s (shorter than filtered fMRI wavelength) than ∼100 s (longer than filtered fMRI wavelength), irrespective of the sampling rate of the underlying fMRI data. Narrow-band filtering of fMRI data (0.03-0.07 Hz) yielded a stronger relationship between IPSA and CSWA than wider-band (0.01-0.1 Hz). On a topological level, time-averaged IPSA and CSWA nodes were non-linearly correlated for both short (∼20 s) and long (∼100 s) windows, mainly because nodes with strong negative correlations (CSWA) displayed high phase synchrony (IPSA). IPSA and CSWA were anatomically similar in the default mode network, sensory cortex, insula and cerebellum. Our results suggest that IPSA and CSWA provide comparable characterizations of time-resolved fMRI connectivity for appropriately chosen window lengths. Although IPSA requires narrow-band fMRI filtering, we recommend the use of IPSA given that it does not mandate a (semi-)arbitrary choice of window length and window overlap. A code for calculating IPSA is provided. Copyright © 2018. Published by Elsevier Inc.

Fault Diagnosis of Induction Machines in a Transient Regime Using Current Sensors with an Optimized Slepian Window

PubMed Central

Burriel-Valencia, Jordi; Martinez-Roman, Javier; Sapena-Bano, Angel

2018-01-01

The aim of this paper is to introduce a new methodology for the fault diagnosis of induction machines working in the transient regime, when time-frequency analysis tools are used. The proposed method relies on the use of the optimized Slepian window for performing the short time Fourier transform (STFT) of the stator current signal. It is shown that for a given sequence length of finite duration, the Slepian window has the maximum concentration of energy, greater than can be reached with a gated Gaussian window, which is usually used as the analysis window. In this paper, the use and optimization of the Slepian window for fault diagnosis of induction machines is theoretically introduced and experimentally validated through the test of a 3.15-MW induction motor with broken bars during the start-up transient. The theoretical analysis and the experimental results show that the use of the Slepian window can highlight the fault components in the current’s spectrogram with a significant reduction of the required computational resources. PMID:29316650

Fault Diagnosis of Induction Machines in a Transient Regime Using Current Sensors with an Optimized Slepian Window.

PubMed

Burriel-Valencia, Jordi; Puche-Panadero, Ruben; Martinez-Roman, Javier; Sapena-Bano, Angel; Pineda-Sanchez, Manuel

2018-01-06

The aim of this paper is to introduce a new methodology for the fault diagnosis of induction machines working in the transient regime, when time-frequency analysis tools are used. The proposed method relies on the use of the optimized Slepian window for performing the short time Fourier transform (STFT) of the stator current signal. It is shown that for a given sequence length of finite duration, the Slepian window has the maximum concentration of energy, greater than can be reached with a gated Gaussian window, which is usually used as the analysis window. In this paper, the use and optimization of the Slepian window for fault diagnosis of induction machines is theoretically introduced and experimentally validated through the test of a 3.15-MW induction motor with broken bars during the start-up transient. The theoretical analysis and the experimental results show that the use of the Slepian window can highlight the fault components in the current's spectrogram with a significant reduction of the required computational resources.

Extracting Strength from Ramp-Release Experiments on Z

NASA Astrophysics Data System (ADS)

Brown, Justin

2013-06-01

Releasing from a compressed state has long been recognized as a sensitive measure of a material's constitutive response. The initial elastic unloading provides insights which can be related to changes in shear stress or, in the context of classic plasticity, to the material's yield surface. Ramp compression and subsequent release experiments on Sandia's Z machine typically consist of a driving aluminum electrode pushing a sample material which is backed by a window. A particle velocity measurement of the sample/window interface provides a ramp-release profile. Under most circumstances, however, the impedance mismatch at this interface results in the measurement of a highly perturbed velocity, particularly at the late times of interest. Wave attenuation, the finite pressure range over which the material elastically unloads, and rate effects additionally complicate the interpretation of the experiment. In an effort to accurately analyze experiments of this type, each of these complications is addressed. The wave interactions are accounted for through the so-called transfer function methodology and involves a coupling of the experimental measurements with numerical simulations. Simulated window velocity measurements are combined with the corresponding in situ simulations to define a mapping describing the wave interactions due to the presence of the window. Applying this mapping to the experimentally measured velocity results in an in situ sample response which may then be used in a classic Lagrangian analysis from which the strength can be extracted via the self-consistent method. Corrections for attenuation, pressure averaging, and limitations of the analysis due to rate-effects are verified through the use of synthetic data. To date, results on the strength of aluminum to 1.2 MBar, beryllium to 1 MBar, and tantalum to over 2 MBar have been obtained through this methodology and will be presented. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin company, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Hydrocarbon Reservoir Prediction Using Bi-Gaussian S Transform Based Time-Frequency Analysis Approach

NASA Astrophysics Data System (ADS)

Cheng, Z.; Chen, Y.; Liu, Y.; Liu, W.; Zhang, G.

2015-12-01

Among those hydrocarbon reservoir detection techniques, the time-frequency analysis based approach is one of the most widely used approaches because of its straightforward indication of low-frequency anomalies from the time-frequency maps, that is to say, the low-frequency bright spots usually indicate the potential hydrocarbon reservoirs. The time-frequency analysis based approach is easy to implement, and more importantly, is usually of high fidelity in reservoir prediction, compared with the state-of-the-art approaches, and thus is of great interest to petroleum geologists, geophysicists, and reservoir engineers. The S transform has been frequently used in obtaining the time-frequency maps because of its better performance in controlling the compromise between the time and frequency resolutions than the alternatives, such as the short-time Fourier transform, Gabor transform, and continuous wavelet transform. The window function used in the majority of previous S transform applications is the symmetric Gaussian window. However, one problem with the symmetric Gaussian window is the degradation of time resolution in the time-frequency map due to the long front taper. In our study, a bi-Gaussian S transform that substitutes the symmetric Gaussian window with an asymmetry bi-Gaussian window is proposed to analyze the multi-channel seismic data in order to predict hydrocarbon reservoirs. The bi-Gaussian window introduces asymmetry in the resultant time-frequency spectrum, with time resolution better in the front direction, as compared with the back direction. It is the first time that the bi-Gaussian S transform is used for analyzing multi-channel post-stack seismic data in order to predict hydrocarbon reservoirs since its invention in 2003. The superiority of the bi-Gaussian S transform over traditional S transform is tested on a real land seismic data example. The performance shows that the enhanced temporal resolution can help us depict more clearly the edge of the hydrocarbon reservoir, especially when the thickness of the reservoir is small (such as the thin beds).

Single-agent parallel window search

NASA Technical Reports Server (NTRS)

Powley, Curt; Korf, Richard E.

1991-01-01

Parallel window search is applied to single-agent problems by having different processes simultaneously perform iterations of Iterative-Deepening-A(asterisk) (IDA-asterisk) on the same problem but with different cost thresholds. This approach is limited by the time to perform the goal iteration. To overcome this disadvantage, the authors consider node ordering. They discuss how global node ordering by minimum h among nodes with equal f = g + h values can reduce the time complexity of serial IDA-asterisk by reducing the time to perform the iterations prior to the goal iteration. Finally, the two ideas of parallel window search and node ordering are combined to eliminate the weaknesses of each approach while retaining the strengths. The resulting approach, called simply parallel window search, can be used to find a near-optimal solution quickly, improve the solution until it is optimal, and then finally guarantee optimality, depending on the amount of time available.

CAVE WINDOW

DOEpatents

Levenson, M.

1960-10-25

A cave window is described. It is constructed of thick glass panes arranged so that interior panes have smaller windowpane areas and exterior panes have larger areas. Exterior panes on the radiation exposure side are remotely replaceable when darkened excessively. Metal shutters minimize exposure time to extend window life.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, Rui; Praggastis, Brenda L.; Smith, William P.

While streaming data have become increasingly more popular in business and research communities, semantic models and processing software for streaming data have not kept pace. Traditional semantic solutions have not addressed transient data streams. Semantic web languages (e.g., RDF, OWL) have typically addressed static data settings and linked data approaches have predominantly addressed static or growing data repositories. Streaming data settings have some fundamental differences; in particular, data are consumed on the fly and data may expire. Stream reasoning, a combination of stream processing and semantic reasoning, has emerged with the vision of providing "smart" processing of streaming data. C-SPARQLmore » is a prominent stream reasoning system that handles semantic (RDF) data streams. Many stream reasoning systems including C-SPARQL use a sliding window and use data arrival time to evict data. For data streams that include expiration times, a simple arrival time scheme is inadequate if the window size does not match the expiration period. In this paper, we propose a cache-enabled, order-aware, ontology-based stream reasoning framework. This framework consumes RDF streams with expiration timestamps assigned by the streaming source. Our framework utilizes both arrival and expiration timestamps in its cache eviction policies. In addition, we introduce the notion of "semantic importance" which aims to address the relevance of data to the expected reasoning, thus enabling the eviction algorithms to be more context- and reasoning-aware when choosing what data to maintain for question answering. We evaluate this framework by implementing three different prototypes and utilizing five metrics. The trade-offs of deploying the proposed framework are also discussed.« less

Online Appointment Scheduling for a Nuclear Medicine Department in a Chinese Hospital

PubMed Central

Feng, Ya-bing

2018-01-01

Nuclear medicine, a subspecialty of radiology, plays an important role in proper diagnosis and timely treatment. Multiple resources, especially short-lived radiopharmaceuticals involved in the process of nuclear medical examination, constitute a unique problem in appointment scheduling. Aiming at achieving scientific and reasonable appointment scheduling in the West China Hospital (WCH), a typical class A tertiary hospital in China, we developed an online appointment scheduling algorithm based on an offline nonlinear integer programming model which considers multiresources allocation, the time window constraints imposed by short-lived radiopharmaceuticals, and the stochastic nature of the patient requests when scheduling patients. A series of experiments are conducted to show the effectiveness of the proposed strategy based on data provided by the WCH. The results show that the examination amount increases by 29.76% compared with the current one with a significant increase in the resource utilization and timely rate. Besides, it also has a high stability for stochastic factors and bears the advantage of convenient and economic operation. PMID:29849748

BIPV-powered smart windows utilizing photovoltaic and electrochromic devices.

PubMed

Ma, Rong-Hua; Chen, Yu-Chia

2012-01-01

A BIPV-powered smart window comprising a building-integrated photovoltaic (BIPV) panel and an all-solid-state electrochromic (EC) stack is proposed. In the proposed device, the output voltage of the BIPV panel varies in accordance with the intensity of the incident light and is modulated in such a way as to generate the EC stack voltage required to maintain the indoor illuminance within a specified range. Two different EC stacks are fabricated and characterized, namely one stack comprising ITO/WO(3)/Ta(2)O(5)/ITO and one stack comprising ITO/WO(3)/lithium-polymer electrolyte/ITO. It is shown that of the two stacks, the ITO/WO(3)/lithium-polymer electrolyte/ITO stack has a larger absorptance (i.e., approximately 99% at a driving voltage of 3.5 V). The experimental results show that the smart window incorporating an ITO/WO(3)/lithium-polymer electrolyte/ITO stack with an electrolyte thickness of 1.0 μm provides an indoor illuminance range of 750-1,500 Lux under typical summertime conditions in Taiwan.

Developmental time windows for axon growth influence neuronal network topology.

PubMed

Lim, Sol; Kaiser, Marcus

2015-04-01

Early brain connectivity development consists of multiple stages: birth of neurons, their migration and the subsequent growth of axons and dendrites. Each stage occurs within a certain period of time depending on types of neurons and cortical layers. Forming synapses between neurons either by growing axons starting at similar times for all neurons (much-overlapped time windows) or at different time points (less-overlapped) may affect the topological and spatial properties of neuronal networks. Here, we explore the extreme cases of axon formation during early development, either starting at the same time for all neurons (parallel, i.e., maximally overlapped time windows) or occurring for each neuron separately one neuron after another (serial, i.e., no overlaps in time windows). For both cases, the number of potential and established synapses remained comparable. Topological and spatial properties, however, differed: Neurons that started axon growth early on in serial growth achieved higher out-degrees, higher local efficiency and longer axon lengths while neurons demonstrated more homogeneous connectivity patterns for parallel growth. Second, connection probability decreased more rapidly with distance between neurons for parallel growth than for serial growth. Third, bidirectional connections were more numerous for parallel growth. Finally, we tested our predictions with C. elegans data. Together, this indicates that time windows for axon growth influence the topological and spatial properties of neuronal networks opening up the possibility to a posteriori estimate developmental mechanisms based on network properties of a developed network.

Sunlight Responsive Thermochromic Window System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Millett, F,A; Byker,H, J

2006-10-27

Pleotint has embarked on a novel approach with our Sunlight Responsive Thermochromic, SRT™, windows. We are integrating dynamic sunlight control, high insulation values and low solar heat gain together in a high performance window. The Pleotint SRT window is dynamic because it reversibly changes light transmission based on thermochromics activated directly by the heating effect of sunlight. We can achieve a window package with low solar heat gain coefficient (SHGC), a low U value and high insulation. At the same time our windows provide good daylighting. Our innovative window design offers architects and building designers the opportunity to choose theirmore » desired energy performance, excellent sound reduction, external pane can be self-cleaning, or a resistance to wind load, blasts, bullets or hurricanes. SRT windows would provide energy savings that are estimated at up to 30% over traditional window systems. Glass fabricators will be able to use existing equipment to make the SRT window while adding value and flexibility to the basic design. Glazing installers will have the ability to fit the windows with traditional methods without wires, power supplies and controllers. SRT windows can be retrofit into existing buildings,« less

Threshold network of a financial market using the P-value of correlation coefficients

NASA Astrophysics Data System (ADS)

Ha, Gyeong-Gyun; Lee, Jae Woo; Nobi, Ashadun

2015-06-01

Threshold methods in financial networks are important tools for obtaining important information about the financial state of a market. Previously, absolute thresholds of correlation coefficients have been used; however, they have no relation to the length of time. We assign a threshold value depending on the size of the time window by using the P-value concept of statistics. We construct a threshold network (TN) at the same threshold value for two different time window sizes in the Korean Composite Stock Price Index (KOSPI). We measure network properties, such as the edge density, clustering coefficient, assortativity coefficient, and modularity. We determine that a significant difference exists between the network properties of the two time windows at the same threshold, especially during crises. This implies that the market information depends on the length of the time window when constructing the TN. We apply the same technique to Standard and Poor's 500 (S&P500) and observe similar results.

Effect of the time window on the heat-conduction information filtering model

NASA Astrophysics Data System (ADS)

Guo, Qiang; Song, Wen-Jun; Hou, Lei; Zhang, Yi-Lu; Liu, Jian-Guo

2014-05-01

Recommendation systems have been proposed to filter out the potential tastes and preferences of the normal users online, however, the physics of the time window effect on the performance is missing, which is critical for saving the memory and decreasing the computation complexity. In this paper, by gradually expanding the time window, we investigate the impact of the time window on the heat-conduction information filtering model with ten similarity measures. The experimental results on the benchmark dataset Netflix indicate that by only using approximately 11.11% recent rating records, the accuracy could be improved by an average of 33.16% and the diversity could be improved by 30.62%. In addition, the recommendation performance on the dataset MovieLens could be preserved by only considering approximately 10.91% recent records. Under the circumstance of improving the recommendation performance, our discoveries possess significant practical value by largely reducing the computational time and shortening the data storage space.

Defining the therapeutic time window for suppressing the inflammatory prostaglandin E2 signaling after status epilepticus

PubMed Central

Du, Yifeng; Kemper, Timothy; Qiu, Jiange; Jiang, Jianxiong

2016-01-01

Neuroinflammation is a common feature in nearly all neurological and some psychiatric disorders. Resembling its extraneural counterpart, neuroinflammation can be both beneficial and detrimental depending on the responding molecules. The overall effect of inflammation on disease progression is highly dependent on the extent of inflammatory mediator production and the duration of inflammatory induction. The time-dependent aspect of inflammatory responses suggests that the therapeutic time window for quelling neuroinflammation might vary with molecular targets and injury types. Therefore, it is important to define the therapeutic time window for anti-inflammatory therapeutics, as contradicting or negative results might arise when different treatment regimens are utilized even in similar animal models. Herein, we discuss a few critical factors that can help define the therapeutic time window and optimize treatment paradigm for suppressing the cyclooxygenase-2/prostaglandin-mediated inflammation after status epilepticus. These determinants should also be relevant to other anti-inflammatory therapeutic strategies for the CNS diseases. PMID:26689339

Trajectories and phenotypes with estrogen exposures across the lifespan: What does Goldilocks have to do with it?

PubMed Central

Koebele, Stephanie V.; Bimonte-Nelson, Heather A.

2015-01-01

Estrogens impact the organization and activation of the mammalian brain in both sexes, with sex-specific critical windows. Throughout the female lifespan estrogens activate brain substrates previously organized by estrogens, and estrogens can induce non-transient brain and behavior changes into adulthood. Therefore, from early life through the transition to reproductive senescence and beyond, estrogens are potent modulators of the brain and behavior. Organizational, reorganizational, and activational hormone events likely impact the trajectory of brain profiles during aging. A “brain profile,” or quantitative brain measurement for research purposes, is typically a snapshot in time, but in life a brain profile is anything but static – it is in flux, variable, and dynamic. Akin to this, the only thing continuous and consistent about hormone exposures across a female's lifespan is that they are noncontinuous and inconsistent, building and rebuilding on past exposures to create a present brain and behavioral landscape. Thus, hormone variation is especially rich in females, and is likely the destiny for maximal responsiveness in the female brain. The magnitude and direction of estrogenic effects on the brain and its functions depend on a myriad of factors; a “Goldilocks” phenomenon exists for estrogens, whereby if the timing, dose, and regimen for an individual are just right, markedly efficacious effects present. Data indicate that exogenously-administered estrogens can bestow beneficial cognitive effects in some circumstances, especially when initiated in a window of opportunity such as the menopause transition. Could it be that the age-related reduction in efficacy of estrogens reflects the closure of a late-in-life critical window occurring around the menopause transition? Information from classic and contemporary works studying organizational/activational estrogen actions, in combination with acknowledging the tendency for maximal responsiveness to cyclicity, will elucidate ways to extend sensitivity and efficacy into post-menopause. PMID:26122297

A randomized approach to speed up the analysis of large-scale read-count data in the application of CNV detection.

PubMed

Wang, WeiBo; Sun, Wei; Wang, Wei; Szatkiewicz, Jin

2018-03-01

The application of high-throughput sequencing in a broad range of quantitative genomic assays (e.g., DNA-seq, ChIP-seq) has created a high demand for the analysis of large-scale read-count data. Typically, the genome is divided into tiling windows and windowed read-count data is generated for the entire genome from which genomic signals are detected (e.g. copy number changes in DNA-seq, enrichment peaks in ChIP-seq). For accurate analysis of read-count data, many state-of-the-art statistical methods use generalized linear models (GLM) coupled with the negative-binomial (NB) distribution by leveraging its ability for simultaneous bias correction and signal detection. However, although statistically powerful, the GLM+NB method has a quadratic computational complexity and therefore suffers from slow running time when applied to large-scale windowed read-count data. In this study, we aimed to speed up substantially the GLM+NB method by using a randomized algorithm and we demonstrate here the utility of our approach in the application of detecting copy number variants (CNVs) using a real example. We propose an efficient estimator, the randomized GLM+NB coefficients estimator (RGE), for speeding up the GLM+NB method. RGE samples the read-count data and solves the estimation problem on a smaller scale. We first theoretically validated the consistency and the variance properties of RGE. We then applied RGE to GENSENG, a GLM+NB based method for detecting CNVs. We named the resulting method as "R-GENSENG". Based on extensive evaluation using both simulated and empirical data, we concluded that R-GENSENG is ten times faster than the original GENSENG while maintaining GENSENG's accuracy in CNV detection. Our results suggest that RGE strategy developed here could be applied to other GLM+NB based read-count analyses, i.e. ChIP-seq data analysis, to substantially improve their computational efficiency while preserving the analytic power.

Spurious One-Month and One-Year Periods in Visual Observations of Variable Stars

NASA Astrophysics Data System (ADS)

Percy, J. R.

2015-12-01

Visual observations of variable stars, when time-series analyzed with some algorithms such as DC-DFT in vstar, show spurious periods at or close to one synodic month (29.5306 days), and also at about a year, with an amplitude of typically a few hundredths of a magnitude. The one-year periods have been attributed to the Ceraski effect, which was believed to be a physiological effect of the visual observing process. This paper reports on time-series analysis, using DC-DFT in vstar, of visual observations (and in some cases, V observations) of a large number of stars in the AAVSO International Database, initially to investigate the one-month periods. The results suggest that both the one-month and one-year periods are actually due to aliasing of the stars' very low-frequency variations, though they do not rule out very low-amplitude signals (typically 0.01 to 0.02 magnitude) which may be due to a different process, such as a physiological one. Most or all of these aliasing effects may be avoided by using a different algorithm, which takes explicit account of the window function of the data, and/or by being fully aware of the possible presence of and aliasing by very low-frequency variations.

Performance analysis of the Microsoft Kinect sensor for 2D Simultaneous Localization and Mapping (SLAM) techniques.

PubMed

Kamarudin, Kamarulzaman; Mamduh, Syed Muhammad; Shakaff, Ali Yeon Md; Zakaria, Ammar

2014-12-05

This paper presents a performance analysis of two open-source, laser scanner-based Simultaneous Localization and Mapping (SLAM) techniques (i.e., Gmapping and Hector SLAM) using a Microsoft Kinect to replace the laser sensor. Furthermore, the paper proposes a new system integration approach whereby a Linux virtual machine is used to run the open source SLAM algorithms. The experiments were conducted in two different environments; a small room with no features and a typical office corridor with desks and chairs. Using the data logged from real-time experiments, each SLAM technique was simulated and tested with different parameter settings. The results show that the system is able to achieve real time SLAM operation. The system implementation offers a simple and reliable way to compare the performance of Windows-based SLAM algorithm with the algorithms typically implemented in a Robot Operating System (ROS). The results also indicate that certain modifications to the default laser scanner-based parameters are able to improve the map accuracy. However, the limited field of view and range of Kinect's depth sensor often causes the map to be inaccurate, especially in featureless areas, therefore the Kinect sensor is not a direct replacement for a laser scanner, but rather offers a feasible alternative for 2D SLAM tasks.

Performance Analysis of the Microsoft Kinect Sensor for 2D Simultaneous Localization and Mapping (SLAM) Techniques

PubMed Central

Kamarudin, Kamarulzaman; Mamduh, Syed Muhammad; Shakaff, Ali Yeon Md; Zakaria, Ammar

2014-01-01

This paper presents a performance analysis of two open-source, laser scanner-based Simultaneous Localization and Mapping (SLAM) techniques (i.e., Gmapping and Hector SLAM) using a Microsoft Kinect to replace the laser sensor. Furthermore, the paper proposes a new system integration approach whereby a Linux virtual machine is used to run the open source SLAM algorithms. The experiments were conducted in two different environments; a small room with no features and a typical office corridor with desks and chairs. Using the data logged from real-time experiments, each SLAM technique was simulated and tested with different parameter settings. The results show that the system is able to achieve real time SLAM operation. The system implementation offers a simple and reliable way to compare the performance of Windows-based SLAM algorithm with the algorithms typically implemented in a Robot Operating System (ROS). The results also indicate that certain modifications to the default laser scanner-based parameters are able to improve the map accuracy. However, the limited field of view and range of Kinect's depth sensor often causes the map to be inaccurate, especially in featureless areas, therefore the Kinect sensor is not a direct replacement for a laser scanner, but rather offers a feasible alternative for 2D SLAM tasks. PMID:25490595

Smart windows with functions of reflective display and indoor temperature-control

NASA Astrophysics Data System (ADS)

Lee, I.-Hui; Chao, Yu-Ching; Hsu, Chih-Cheng; Chang, Liang-Chao; Chiu, Tien-Lung; Lee, Jiunn-Yih; Kao, Fu-Jen; Lee, Chih-Kung; Lee, Jiun-Haw

2010-02-01

In this paper, a switchable window based on cholestreric liquid crystal (CLC) was demonstrated. Under different applied voltages, incoming light at visible and infrared wavelengths was modulated, respectively. A mixture of CLC with a nematic liquid crystal and a chiral dopant selectively reflected infrared light without bias, which effectively reduced the indoor temperature under sunlight illumination. At this time, transmission at visible range was kept at high and the windows looked transparent. With increasing the voltage to 15V, CLC changed to focal conic state and can be used as a reflective display, a privacy window, or a screen for projector. Under a high voltage (30V), homeotropic state was achieved. At this time, both infrared and visible light can transmit which acted as a normal window, which permitted infrared spectrum of winter sunlight to enter the room so as to reduce the heating requirement. Such a device can be used as a switchable window in smart buildings, green houses and windshields.

Bird-Window Collisions at a West-Coast Urban Park Museum: Analyses of Bird Biology and Window Attributes from Golden Gate Park, San Francisco.

PubMed

Kahle, Logan Q; Flannery, Maureen E; Dumbacher, John P

2016-01-01

Bird-window collisions are a major and poorly-understood generator of bird mortality. In North America, studies of this topic tend to be focused east of the Mississippi River, resulting in a paucity of data from the Western flyways. Additionally, few available data can critically evaluate factors such as time of day, sex and age bias, and effect of window pane size on collisions. We collected and analyzed 5 years of window strike data from a 3-story building in a large urban park in San Francisco, California. To evaluate our window collision data in context, we collected weekly data on local bird abundance in the adjacent parkland. Our study asks two overarching questions: first-what aspects of a bird's biology might make them more likely to fatally strike windows; and second, what characteristics of a building's design contribute to bird-window collisions. We used a dataset of 308 fatal bird strikes to examine the relationships of strikes relative to age, sex, time of day, time of year, and a variety of other factors, including mitigation efforts. We found that actively migrating birds may not be major contributors to collisions as has been found elsewhere. We found that males and young birds were both significantly overrepresented relative to their abundance in the habitat surrounding the building. We also analyzed the effect of external window shades as mitigation, finding that an overall reduction in large panes, whether covered or in some way broken up with mullions, effectively reduced window collisions. We conclude that effective mitigation or design will be required in all seasons, but that breeding seasons and migratory seasons are most critical, especially for low-rise buildings and other sites away from urban migrant traps. Finally, strikes occur throughout the day, but mitigation may be most effective in the morning and midday.

Bird-Window Collisions at a West-Coast Urban Park Museum: Analyses of Bird Biology and Window Attributes from Golden Gate Park, San Francisco

PubMed Central

Kahle, Logan Q.; Flannery, Maureen E.; Dumbacher, John P.

2016-01-01

Bird-window collisions are a major and poorly-understood generator of bird mortality. In North America, studies of this topic tend to be focused east of the Mississippi River, resulting in a paucity of data from the Western flyways. Additionally, few available data can critically evaluate factors such as time of day, sex and age bias, and effect of window pane size on collisions. We collected and analyzed 5 years of window strike data from a 3-story building in a large urban park in San Francisco, California. To evaluate our window collision data in context, we collected weekly data on local bird abundance in the adjacent parkland. Our study asks two overarching questions: first–what aspects of a bird’s biology might make them more likely to fatally strike windows; and second, what characteristics of a building’s design contribute to bird-window collisions. We used a dataset of 308 fatal bird strikes to examine the relationships of strikes relative to age, sex, time of day, time of year, and a variety of other factors, including mitigation efforts. We found that actively migrating birds may not be major contributors to collisions as has been found elsewhere. We found that males and young birds were both significantly overrepresented relative to their abundance in the habitat surrounding the building. We also analyzed the effect of external window shades as mitigation, finding that an overall reduction in large panes, whether covered or in some way broken up with mullions, effectively reduced window collisions. We conclude that effective mitigation or design will be required in all seasons, but that breeding seasons and migratory seasons are most critical, especially for low-rise buildings and other sites away from urban migrant traps. Finally, strikes occur throughout the day, but mitigation may be most effective in the morning and midday. PMID:26731417

MOLA Global roughness map of Mars

NASA Technical Reports Server (NTRS)

2000-01-01

The median of slopes in 35-km windows indicate the typical roughness on 300-meter baselines. The rougher nature of the heavily cratered terrain in the Southern Hemisphere is apparent, as well as that of Valles Marineris (12S, 289E) canyon walls and the Olympus Mons (18N, 227E) aureole deposits. The Northern Lowlands are smooth, especially Amazonis Planitia (16N, 202E), a region to the west of Olympus Mons, were typical median slopes on these baselines are often smaller than 0.1 degree. A shaded relief map of the topography is overlaid is monochrome.

Free Classification as a Window on Executive Functioning in Autism Spectrum Disorders

ERIC Educational Resources Information Center

McGonigle-Chalmers, Margaret; Alderson-Day, Ben

2010-01-01

Spontaneous classification was assessed using a free serial search task in 18 school-aged children at the high functioning end of the autistic spectrum and compared with results from age-matched typically developing controls. The task required participants to touch shapes in an exhaustive non-repetitive sequence. The positions of the items varied…

The Status of Primary School Buildings in the Rural Villages of Pakistan, 1976.

ERIC Educational Resources Information Center

Hussain, Farhat; Eastmond, Jefferson N.

An April-May 1976 nationwide sample of more than 800 schools in rural Pakistan provides data to form composite pictures of the typical boys school and girls school. An observation checklist records such aspects as: (1) government ownership of building; (2) structural soundness and maintenance of walls, roof, veranda, steps, floors, windows; (3)…

The Impact of Summer Learning Loss on Measures of School Performance

ERIC Educational Resources Information Center

McEachin, Andrew; Atteberry, Allison

2017-01-01

State and federal accountability policies are predicated on the ability to estimate valid and reliable measures of school impacts on student learning. The typical spring-to-spring testing window potentially conflates the amount of learning that occurs during the school year with learning that occurs during the summer. We use a unique dataset to…

From Sunshine to Double Arrows: An Evaluation Window Account of Negative Compatibility Effects

ERIC Educational Resources Information Center

Klauer, Karl Christoph; Dittrich, Kerstin

2010-01-01

In category priming, target stimuli are to be sorted into 2 categories. Prime stimuli preceding targets typically facilitate processing of targets when primes and targets are members of the same category, relative to the case in which both stem from different categories, a positive compatibility effect (PCE). But negative compatibility effects…

Optimal Window and Lattice in Gabor Transform. Application to Audio Analysis.

PubMed

Lachambre, Helene; Ricaud, Benjamin; Stempfel, Guillaume; Torrésani, Bruno; Wiesmeyr, Christoph; Onchis-Moaca, Darian

2015-01-01

This article deals with the use of optimal lattice and optimal window in Discrete Gabor Transform computation. In the case of a generalized Gaussian window, extending earlier contributions, we introduce an additional local window adaptation technique for non-stationary signals. We illustrate our approach and the earlier one by addressing three time-frequency analysis problems to show the improvements achieved by the use of optimal lattice and window: close frequencies distinction, frequency estimation and SNR estimation. The results are presented, when possible, with real world audio signals.

An Efficient Adaptive Window Size Selection Method for Improving Spectrogram Visualization.

PubMed

Nisar, Shibli; Khan, Omar Usman; Tariq, Muhammad

2016-01-01

Short Time Fourier Transform (STFT) is an important technique for the time-frequency analysis of a time varying signal. The basic approach behind it involves the application of a Fast Fourier Transform (FFT) to a signal multiplied with an appropriate window function with fixed resolution. The selection of an appropriate window size is difficult when no background information about the input signal is known. In this paper, a novel empirical model is proposed that adaptively adjusts the window size for a narrow band-signal using spectrum sensing technique. For wide-band signals, where a fixed time-frequency resolution is undesirable, the approach adapts the constant Q transform (CQT). Unlike the STFT, the CQT provides a varying time-frequency resolution. This results in a high spectral resolution at low frequencies and high temporal resolution at high frequencies. In this paper, a simple but effective switching framework is provided between both STFT and CQT. The proposed method also allows for the dynamic construction of a filter bank according to user-defined parameters. This helps in reducing redundant entries in the filter bank. Results obtained from the proposed method not only improve the spectrogram visualization but also reduce the computation cost and achieves 87.71% of the appropriate window length selection.

Mitigation of Collision Hazard for the International Space Station (ISS) from Globally Launched Objects

NASA Astrophysics Data System (ADS)

Schultz, Eric D.; Wilde, Paul D.

2013-09-01

For the International Space Station (ISS), it can take 6 to 24 hours to reliably catalog a newly disposed upper stage and up to 33 hours to plan and execute an avoidance maneuver. This creates a gap in the existing collision risk protection for newly launched vehicles, which covers the period when these launched objects are still under propulsive control; specifically, upper stage separation plus 100 minutes for most missions. This gap results in a vulnerability of the ISS from the end of current "Launch Collision Avoidance (COLA)" protection until approximately launch plus 56 hours.In order to help mitigate this gap, conjunction analyses are being developed that identify launch times when the disposed upper stage could violate safe separation distances from the ISS. Launch window cut-out times can be determined from the analysis and implemented to protect the ISS.The COLA Gap is considered to be a risk to ISS operations and vehicle safety. Methods can be used to mitigate the risk, but the criteria and process need to be established and developed in order to reduce operational disruptions and potential risk to ISS vehicle. New requirements and analytical methods can close the current COLA gap with minimal impact to typical launch windows for Geo-Transfer Orbit (GTO) and direct injection missions. Also, strategies can be established to produce common standards in the U.S. and the world to close the current Launch COLA gap.

Evaluation of SNS Beamline Shielding Configurations using MCNPX Accelerated by ADVANTG

DOE Office of Scientific and Technical Information (OSTI.GOV)

Risner, Joel M; Johnson, Seth R.; Remec, Igor

2015-01-01

Shielding analyses for the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory pose significant computational challenges, including highly anisotropic high-energy sources, a combination of deep penetration shielding and an unshielded beamline, and a desire to obtain well-converged nearly global solutions for mapping of predicted radiation fields. The majority of these analyses have been performed using MCNPX with manually generated variance reduction parameters (source biasing and cell-based splitting and Russian roulette) that were largely based on the analyst's insight into the problem specifics. Development of the variance reduction parameters required extensive analyst time, and was often tailored to specific portionsmore » of the model phase space. We previously applied a developmental version of the ADVANTG code to an SNS beamline study to perform a hybrid deterministic/Monte Carlo analysis and showed that we could obtain nearly global Monte Carlo solutions with essentially uniform relative errors for mesh tallies that cover extensive portions of the model with typical voxel spacing of a few centimeters. The use of weight window maps and consistent biased sources produced using the FW-CADIS methodology in ADVANTG allowed us to obtain these solutions using substantially less computer time than the previous cell-based splitting approach. While those results were promising, the process of using the developmental version of ADVANTG was somewhat laborious, requiring user-developed Python scripts to drive much of the analysis sequence. In addition, limitations imposed by the size of weight-window files in MCNPX necessitated the use of relatively coarse spatial and energy discretization for the deterministic Denovo calculations that we used to generate the variance reduction parameters. We recently applied the production version of ADVANTG to this beamline analysis, which substantially streamlined the analysis process. We also tested importance function collapsing (in space and energy) capabilities in ADVANTG. These changes, along with the support for parallel Denovo calculations using the current version of ADVANTG, give us the capability to improve the fidelity of the deterministic portion of the hybrid analysis sequence, obtain improved weight-window maps, and reduce both the analyst and computational time required for the analysis process.« less

Communicating likelihoods and probabilities in forecasts of volcanic eruptions

NASA Astrophysics Data System (ADS)

Doyle, Emma E. H.; McClure, John; Johnston, David M.; Paton, Douglas

2014-02-01

The issuing of forecasts and warnings of natural hazard events, such as volcanic eruptions, earthquake aftershock sequences and extreme weather often involves the use of probabilistic terms, particularly when communicated by scientific advisory groups to key decision-makers, who can differ greatly in relative expertise and function in the decision making process. Recipients may also differ in their perception of relative importance of political and economic influences on interpretation. Consequently, the interpretation of these probabilistic terms can vary greatly due to the framing of the statements, and whether verbal or numerical terms are used. We present a review from the psychology literature on how the framing of information influences communication of these probability terms. It is also unclear as to how people rate their perception of an event's likelihood throughout a time frame when a forecast time window is stated. Previous research has identified that, when presented with a 10-year time window forecast, participants viewed the likelihood of an event occurring ‘today’ as being of less than that in year 10. Here we show that this skew in perception also occurs for short-term time windows (under one week) that are of most relevance for emergency warnings. In addition, unlike the long-time window statements, the use of the phrasing “within the next…” instead of “in the next…” does not mitigate this skew, nor do we observe significant differences between the perceived likelihoods of scientists and non-scientists. This finding suggests that effects occurring due to the shorter time window may be ‘masking’ any differences in perception due to wording or career background observed for long-time window forecasts. These results have implications for scientific advice, warning forecasts, emergency management decision-making, and public information as any skew in perceived event likelihood towards the end of a forecast time window may result in an underestimate of the likelihood of an event occurring ‘today’ leading to potentially inappropriate action choices. We thus present some initial guidelines for communicating such eruption forecasts.

User's Guide, software for reduction and analysis of daily weather and surface-water data: Tools for time series analysis of precipitation, temperature, and streamflow data

USGS Publications Warehouse

Hereford, Richard

2006-01-01

The software described here is used to process and analyze daily weather and surface-water data. The programs are refinements of earlier versions that include minor corrections and routines to calculate frequencies above a threshold on an annual or seasonal basis. Earlier versions of this software were used successfully to analyze historical precipitation patterns of the Mojave Desert and the southern Colorado Plateau regions, ecosystem response to climate variation, and variation of sediment-runoff frequency related to climate (Hereford and others, 2003; 2004; in press; Griffiths and others, 2006). The main program described here (Day_Cli_Ann_v5.3) uses daily data to develop a time series of various statistics for a user specified accounting period such as a year or season. The statistics include averages and totals, but the emphasis is on the frequency of occurrence in days of relatively rare weather or runoff events. These statistics are indices of climate variation; for a discussion of climate indices, see the Climate Research Unit website of the University of East Anglia (http://www.cru.uea.ac.uk/projects/stardex/) and the Climate Change Indices web site (http://cccma.seos.uvic.ca/ETCCDMI/indices.html). Specifically, the indices computed with this software are the frequency of high intensity 24-hour rainfall, unusually warm temperature, and unusually high runoff. These rare, or extreme events, are those greater than the 90th percentile of precipitation, streamflow, or temperature computed for the period of record of weather or gaging stations. If they cluster in time over several decades, extreme events may produce detectable change in the physical landscape and ecosystem of a given region. Although the software has been tested on a variety of data, as with any software, the user should carefully evaluate the results with their data. The programs were designed for the range of precipitation, temperature, and streamflow measurements expected in the semiarid Southwest United States. The user is encouraged to review the examples provided with the software. The software is written in Fortran 90 with Fortran 95 extensions and was compiled with the Digital Visual Fortran compiler version 6.6. The executables run on Windows 2000 and XP, and they operate in a MS-DOS console window that has only very simple graphical options such as font size and color, background color, and size of the window. Error trapping was not written into the programs. Typically, when an error occurs, the console window closes without a message.

Star-Shaped Crack Pattern of Broken Windows

NASA Astrophysics Data System (ADS)

Vandenberghe, Nicolas; Vermorel, Romain; Villermaux, Emmanuel

2013-04-01

Broken thin brittle plates like windows and windshields are ubiquitous in our environment. When impacted locally, they typically present a pattern of cracks extending radially outward from the impact point. We study the variation of the pattern of cracks by performing controlled transverse impacts on brittle plates over a broad range of impact speed, plate thickness, and material properties, and we establish from experiments a global scaling law for the number of radial cracks incorporating all these parameters. A model based on Griffith’s theory of fracture combining bending elastic energy and fracture energy accounts for our observations. These findings indicate how the postmortem shape of broken samples are related to material properties and impact parameters, a procedure relevant to forensic science, archaeology, or astrophysics.

Surface Transient Binding-Based Fluorescence Correlation Spectroscopy (STB-FCS), a Simple and Easy-to-Implement Method to Extend the Upper Limit of the Time Window to Seconds.

PubMed

Peng, Sijia; Wang, Wenjuan; Chen, Chunlai

2018-05-10

Fluorescence correlation spectroscopy is a powerful single-molecule tool that is able to capture kinetic processes occurring at the nanosecond time scale. However, the upper limit of its time window is restricted by the dwell time of the molecule of interest in the confocal detection volume, which is usually around submilliseconds for a freely diffusing biomolecule. Here, we present a simple and easy-to-implement method, named surface transient binding-based fluorescence correlation spectroscopy (STB-FCS), which extends the upper limit of the time window to seconds. We further demonstrated that STB-FCS enables capture of both intramolecular and intermolecular kinetic processes whose time scales cross several orders of magnitude.

MrEnt: an editor for publication-quality phylogenetic tree illustrations.

PubMed

Zuccon, Alessandro; Zuccon, Dario

2014-09-01

We developed MrEnt, a Windows-based, user-friendly software that allows the production of complex, high-resolution, publication-quality phylogenetic trees in few steps, directly from the analysis output. The program recognizes the standard Nexus tree format and the annotated tree files produced by BEAST and MrBayes. MrEnt combines in a single software a large suite of tree manipulation functions (e.g. handling of multiple trees, tree rotation, character mapping, node collapsing, compression of large clades, handling of time scale and error bars for chronograms) with drawing tools typical of standard graphic editors, including handling of graphic elements and images. The tree illustration can be printed or exported in several standard formats suitable for journal publication, PowerPoint presentation or Web publication. © 2014 John Wiley & Sons Ltd.

Survival After Accidental Extrahepatic Distribution of Y90 Microspheres to the Mesentery During a Radioembolization Procedure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sabet, Amir; Ahmadzadehfar, Hojjat; Schaefer, Nico

2012-08-15

We present the acute management and outcome of a patient after an accidental mesenteric distribution of Y90 microspheres during radioembolization (RE). This report describes and highlights: (1) the incidence of a significant reflux during a RE session while injecting into a replaced right hepatic artery from the superior mesenteric artery, (2) the appearance of diffuse mesenteric Y90 distribution in bremsstrahlung-imaging, (3) the management protocol with the radiation protection agent amifostine, (4) the development of typical adverse effects in the expected time window, and (5) survival of the patient without long-term sequelae. This report should sensitize physicians to this particular problemmore » and may help to avoid as well as manage similar radioembolization incidences.« less

Region of interest and windowing-based progressive medical image delivery using JPEG2000

NASA Astrophysics Data System (ADS)

Nagaraj, Nithin; Mukhopadhyay, Sudipta; Wheeler, Frederick W.; Avila, Ricardo S.

2003-05-01

An important telemedicine application is the perusal of CT scans (digital format) from a central server housed in a healthcare enterprise across a bandwidth constrained network by radiologists situated at remote locations for medical diagnostic purposes. It is generally expected that a viewing station respond to an image request by displaying the image within 1-2 seconds. Owing to limited bandwidth, it may not be possible to deliver the complete image in such a short period of time with traditional techniques. In this paper, we investigate progressive image delivery solutions by using JPEG 2000. An estimate of the time taken in different network bandwidths is performed to compare their relative merits. We further make use of the fact that most medical images are 12-16 bits, but would ultimately be converted to an 8-bit image via windowing for display on the monitor. We propose a windowing progressive RoI technique to exploit this and investigate JPEG 2000 RoI based compression after applying a favorite or a default window setting on the original image. Subsequent requests for different RoIs and window settings would then be processed at the server. For the windowing progressive RoI mode, we report a 50% reduction in transmission time.

Hospital-treated mental and behavioral disorders and risk of Alzheimer's disease: A nationwide nested case-control study.

PubMed

Tapiainen, V; Hartikainen, S; Taipale, H; Tiihonen, J; Tolppanen, A-M

2017-06-01

Studies investigating psychiatric disorders as Alzheimer's disease (AD) risk factors have yielded heterogeneous findings. Differences in time windows between the exposure and outcome could be one explanation. We examined whether (1) mental and behavioral disorders in general or (2) specific mental and behavioral disorder categories increase the risk of AD and (3) how the width of the time window between the exposure and outcome affects the results. A nationwide nested case-control study of all Finnish clinically verified AD cases, alive in 2005 and their age, sex and region of residence matched controls (n of case-control pairs 27,948). History of hospital-treated mental and behavioral disorders was available since 1972. Altogether 6.9% (n=1932) of the AD cases and 6.4% (n=1784) of controls had a history of any mental and behavioral disorder. Having any mental and behavioral disorder (adjusted OR=1.07, 95% CI=1.00-1.16) or depression/other mood disorder (adjusted OR=1.17, 95% CI=1.05-1.30) were associated with higher risk of AD with 5-year time window but not with 10-year time window (adjusted OR, 95% CI 0.99, 0.91-1.08 for any disorder and 1.08, 0.96-1.23 for depression). The associations between mental and behavioral disorders and AD were modest and dependent on the time window. Therefore, some of the disorders may represent misdiagnosed prodromal symptoms of AD, which underlines the importance of proper differential diagnostics among older persons. These findings also highlight the importance of appropriate time window in psychiatric and neuroepidemiology research. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Human Mars Mission: Launch Window from Earth Orbit. Pt. 1

NASA Technical Reports Server (NTRS)

Young, Archie

1999-01-01

The determination of orbital window characteristics is of major importance in the analysis of human interplanetary missions and systems. The orbital launch window characteristics are directly involved in the selection of mission trajectories, the development of orbit operational concepts, and the design of orbital launch systems. The orbital launch window problem arises because of the dynamic nature of the relative geometry between outgoing (departure) asymptote of the hyperbolic escape trajectory and the earth parking orbit. The orientation of the escape hyperbola asymptotic relative to earth is a function of time. The required hyperbola energy level also varies with time. In addition, the inertial orientation of the parking orbit is a function of time because of the perturbations caused by the Earth's oblateness. Thus, a coplanar injection onto the escape hyperbola can be made only at a point in time when the outgoing escape asymptote is contained by the plane of parking orbit. Even though this condition may be planned as a nominal situation, it will not generally represent the more probable injection geometry. The general case of an escape injection maneuver performed at a time other than the coplanar time will involve both a path angle and plane change and, therefore, a DELTA V penalty. Usually, because of the DELTA V penalty the actual departure injection window is smaller in duration than that determined by energy requirement alone. This report contains the formulation, characteristics, and test cases for five different launch window modes for Earth orbit. These modes are: (1) One impulsive maneuver from a Highly Elliptical Orbit (HEO) (2) Two impulsive maneuvers from a Highly Elliptical Orbit (HEO) (3) One impulsive maneuver from a Low Earth Orbit (LEO) (4) Two impulsive maneuvers from LEO (5) Three impulsive maneuvers from LEO.

Calculation of Retention Time Tolerance Windows with Absolute Confidence from Shared Liquid Chromatographic Retention Data

PubMed Central

Boswell, Paul G.; Abate-Pella, Daniel; Hewitt, Joshua T.

2015-01-01

Compound identification by liquid chromatography-mass spectrometry (LC-MS) is a tedious process, mainly because authentic standards must be run on a user’s system to be able to confidently reject a potential identity from its retention time and mass spectral properties. Instead, it would be preferable to use shared retention time/index data to narrow down the identity, but shared data cannot be used to reject candidates with an absolute level of confidence because the data are strongly affected by differences between HPLC systems and experimental conditions. However, a technique called “retention projection” was recently shown to account for many of the differences. In this manuscript, we discuss an approach to calculate appropriate retention time tolerance windows for projected retention times, potentially making it possible to exclude candidates with an absolute level of confidence, without needing to have authentic standards of each candidate on hand. In a range of multi-segment gradients and flow rates run among seven different labs, the new approach calculated tolerance windows that were significantly more appropriate for each retention projection than global tolerance windows calculated for retention projections or linear retention indices. Though there were still some small differences between the labs that evidently were not taken into account, the calculated tolerance windows only needed to be relaxed by 50% to make them appropriate for all labs. Even then, 42% of the tolerance windows calculated in this study without standards were narrower than those required by WADA for positive identification, where standards must be run contemporaneously. PMID:26292624

Calculation of retention time tolerance windows with absolute confidence from shared liquid chromatographic retention data.

PubMed

Boswell, Paul G; Abate-Pella, Daniel; Hewitt, Joshua T

2015-09-18

Compound identification by liquid chromatography-mass spectrometry (LC-MS) is a tedious process, mainly because authentic standards must be run on a user's system to be able to confidently reject a potential identity from its retention time and mass spectral properties. Instead, it would be preferable to use shared retention time/index data to narrow down the identity, but shared data cannot be used to reject candidates with an absolute level of confidence because the data are strongly affected by differences between HPLC systems and experimental conditions. However, a technique called "retention projection" was recently shown to account for many of the differences. In this manuscript, we discuss an approach to calculate appropriate retention time tolerance windows for projected retention times, potentially making it possible to exclude candidates with an absolute level of confidence, without needing to have authentic standards of each candidate on hand. In a range of multi-segment gradients and flow rates run among seven different labs, the new approach calculated tolerance windows that were significantly more appropriate for each retention projection than global tolerance windows calculated for retention projections or linear retention indices. Though there were still some small differences between the labs that evidently were not taken into account, the calculated tolerance windows only needed to be relaxed by 50% to make them appropriate for all labs. Even then, 42% of the tolerance windows calculated in this study without standards were narrower than those required by WADA for positive identification, where standards must be run contemporaneously. Copyright © 2015 Elsevier B.V. All rights reserved.

A fast algorithm for vertex-frequency representations of signals on graphs

PubMed Central

Jestrović, Iva; Coyle, James L.; Sejdić, Ervin

2016-01-01

The windowed Fourier transform (short time Fourier transform) and the S-transform are widely used signal processing tools for extracting frequency information from non-stationary signals. Previously, the windowed Fourier transform had been adopted for signals on graphs and has been shown to be very useful for extracting vertex-frequency information from graphs. However, high computational complexity makes these algorithms impractical. We sought to develop a fast windowed graph Fourier transform and a fast graph S-transform requiring significantly shorter computation time. The proposed schemes have been tested with synthetic test graph signals and real graph signals derived from electroencephalography recordings made during swallowing. The results showed that the proposed schemes provide significantly lower computation time in comparison with the standard windowed graph Fourier transform and the fast graph S-transform. Also, the results showed that noise has no effect on the results of the algorithm for the fast windowed graph Fourier transform or on the graph S-transform. Finally, we showed that graphs can be reconstructed from the vertex-frequency representations obtained with the proposed algorithms. PMID:28479645

Narrowing the window of inflationary magnetogenesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Markkanen, Tommi; Nurmi, Sami; Räsänen, Syksy

2017-06-01

We consider inflationary magnetogenesis where the conformal symmetry is broken by the term f {sup 2}(φ) F {sub αβ} F {sup αβ}. We assume that the magnetic field power spectrum today between 0.1 and 10{sup 4} Mpc is a power law, with upper and lower limits from observation. This fixes f to be close to a power law in conformal time in the window during inflation when the modes observed today are generated. In contrast to previous work, we do not make any assumptions about the form of f outside these scales. We cover all possible reheating histories, described bymore » an average equation of state −1/3 < w-bar < 1. Requiring that strong coupling and large backreaction are avoided both at the background and perturbative level, we find the bound δ {sub B} {sub 0} < 5 ×10{sup −15} ( r /0.07){sup 1/2} κG for the magnetic field generated by inflation, where r is the tensor-to-scalar ratio and κ is a constant related to the form of f . This estimate has an uncertainty of one order of magnitude related to our approximations. The parameter κ is < 100, and values ∼> 1 require a highly fine-tuned form of f ; typical values are orders of magnitude smaller.« less

Determination of melt pool dimensions using DOE-FEM and RSM with process window during SLM of Ti6Al4V powder

NASA Astrophysics Data System (ADS)

Zhuang, Jyun-Rong; Lee, Yee-Ting; Hsieh, Wen-Hsin; Yang, An-Shik

2018-07-01

Selective laser melting (SLM) shows a positive prospect as an additive manufacturing (AM) technique for fabrication of 3D parts with complicated structures. A transient thermal model was developed by the finite element method (FEM) to simulate the thermal behavior for predicting the time evolution of temperature field and melt pool dimensions of Ti6Al4V powder during SLM. The FEM predictions were then compared with published experimental measurements and calculation results for model validation. This study applied the design of experiment (DOE) scheme together with the response surface method (RSM) to conduct the regression analysis based on four processing parameters (exactly, the laser power, scanning speed, preheating temperature and hatch space) for predicting the dimensions of the melt pool in SLM. The preliminary RSM results were used to quantify the effects of those parameters on the melt pool size. The process window was further implemented via two criteria of the width and depth of the molten pool to screen impractical conditions of four parameters for including the practical ranges of processing parameters. The FEM simulations confirmed the good accuracy of the critical RSM models in the predictions of melt pool dimensions for three typical SLM working scenarios.

Parental income and the fruits of labor: Variability in homework efficacy in secondary school.

PubMed

Daw, Jonathan

2012-09-01

Research in the sociology of education has shown that noncognitive traits are important predictors of educational outcomes and a mechanism of the intergenerational transmission of status. However, previous research on this topic typically posits that there is a constant effect of these traits with variable prevalences of these traits by socioeconomic status. Using time spent on homework as an example, I analyze income-based heterogeneity in homework efficacy, defined as the individual effect of study time on academic achievement, using a national U.S. probability sample of secondary students. Higher income students gain more knowledge from their homework time than their counterparts in all grades and all subjects except history, with greater group differences for math than for science and reading. These results are confirmed by models accounting for time-invariant unobserved heterogeneity in the 8th-10th, but not 10th-12th, grade windows. These results imply that increases in the amount of homework assigned may increase the socioeconomic achievement gap in math, science, and reading in secondary school.

Parental income and the fruits of labor: Variability in homework efficacy in secondary school

PubMed Central

Daw, Jonathan

2013-01-01

Research in the sociology of education has shown that noncognitive traits are important predictors of educational outcomes and a mechanism of the intergenerational transmission of status. However, previous research on this topic typically posits that there is a constant effect of these traits with variable prevalences of these traits by socioeconomic status. Using time spent on homework as an example, I analyze income-based heterogeneity in homework efficacy, defined as the individual effect of study time on academic achievement, using a national U.S. probability sample of secondary students. Higher income students gain more knowledge from their homework time than their counterparts in all grades and all subjects except history, with greater group differences for math than for science and reading. These results are confirmed by models accounting for time-invariant unobserved heterogeneity in the 8th–10th, but not 10th–12th, grade windows. These results imply that increases in the amount of homework assigned may increase the socioeconomic achievement gap in math, science, and reading in secondary school. PMID:23704804

Rarefaction windows in a high-power impulse magnetron sputtering plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palmucci, Maria; Britun, Nikolay; Konstantinidis, Stephanos

2013-09-21

The velocity distribution function of the sputtered particles in the direction parallel to the planar magnetron cathode is studied by spatially- and time-resolved laser-induced fluorescence spectroscopy in a short-duration (20 μs) high-power impulse magnetron sputtering discharge. The experimental evidence for the neutral and ionized sputtered particles to have a constant (saturated) velocity at the end of the plasma on-time is demonstrated. The velocity component parallel to the target surface reaches the values of about 5 km/s for Ti atoms and ions, which is higher that the values typically measured in the direct current sputtering discharges before. The results point outmore » on the presence of a strong gas rarefaction significantly reducing the sputtered particles energy dissipation during a certain time interval at the end of the plasma pulse, referred to as “rarefaction window” in this work. The obtained results agree with and essentially clarify the dynamics of HiPIMS discharge studied during the plasma off-time previously in the work: N. Britun, Appl. Phys. Lett. 99, 131504 (2011)« less

pH-dependent solubility and permeability profiles: A useful tool for prediction of oral bioavailability.

PubMed

Sieger, P; Cui, Y; Scheuerer, S

2017-07-15

pH-dependent solubility - permeability profiles offer a simple way to predict bioavailability after oral application, if bioavailability is only solubility and permeability driven. Combining both pH-dependent solubility and pH-dependent permeability in one diagram provides a pH-window (=ΔpH sol-perm ) from which the conditions for optimal oral bioavailability can be taken. The size of this window is directly proportional to the observed oral bioavailability. A set of 21 compounds, with known absolute human oral bioavailability, was used to establish this correlation. Compounds with ΔpH sol-perm <2 exhibit poor oral bioavailability (<25%). An increase of ΔpH sol-perm by one pH-unit increases oral bioavailability typically by approximately 25%. For compounds where ΔpH sol-perm ≥3 but still showing poor bioavailability, most probably other pharmacokinetic aspects (e.g. high clearance), are limiting exposure. Interestingly, the location of this pH-window seems to have a negligible influence on the observed oral bioavailability. In scenarios, where the bioavailability is impaired by certain factors, like for example proton pump inhibitor co-medication or food intake, the exact position of this pH-window might be beneficial for understanding the root cause. Copyright © 2017 Elsevier B.V. All rights reserved.

77 FR 46950 - Post Office Organization and Administration: Establishment, Classification, and Discontinuance

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-07

... defines a remotely managed Post Office (RMPO) as a Post Office that offers part-time window service hours... Administrative Post Office. The final rule also defines a part-time Post Office (PTPO) as a Post Office that offers part-time window service hours, is staffed by a Postal Service employee, and reports to a district...

Technologies for precision manufacture of current and future windows and domes

NASA Astrophysics Data System (ADS)

Hallock, Bob; Shorey, Aric

2009-05-01

The final finish and characterization of windows and domes presents a number of challenges in achieving desired precision with acceptable cost and schedule. This becomes more difficult with advanced materials and as window and dome shapes and requirements become more complex, including acute angle corners, transmitted wavefront specifications, aspheric geometries and trending toward conformal surfaces. Magnetorheological Finishing (MRF®) and Magnetorheological Jet (MR Jet®), along with metrology provided by Sub-aperture Stitching Interferometry (SSI®) have several unique attributes that provide them advantages in enhancing fabrication of current and next generation windows and domes. The advantages that MRF brings to the precision finishing of a wide range of shapes such as flats, spheres (including hemispheres), cylinders, aspheres and even freeform optics, has been well documented. Recent advancements include the ability to finish freeform shapes up to 2-meters in size as well as progress in finishing challenging IR materials. Due to its shear-based removal mechanism in contrast to the pressure-based process of other techniques, edges are not typically rolled, in particular on parts with acute angle corners. MR Jet provides additional benefits, particularly in the finishing of the inside of steep concave domes and other irregular shapes. The ability of MR Jet to correct the figure of conformal domes deterministically and to high precision has been demonstrated. Combining these technologies with metrology techniques, such as SSI provides a solution for finishing current and future windows and domes in a reliable, deterministic and cost-effective way. The ability to use the SSI to characterize a range of shapes such as domes and aspheres, as well as progress in using MRF and MR Jet for finishing conventional and conformal windows and domes with increasing size and complexity of design will be presented.

Recalibration of the Multisensory Temporal Window of Integration Results from Changing Task Demands

PubMed Central

Mégevand, Pierre; Molholm, Sophie; Nayak, Ashabari; Foxe, John J.

2013-01-01

The notion of the temporal window of integration, when applied in a multisensory context, refers to the breadth of the interval across which the brain perceives two stimuli from different sensory modalities as synchronous. It maintains a unitary perception of multisensory events despite physical and biophysical timing differences between the senses. The boundaries of the window can be influenced by attention and past sensory experience. Here we examined whether task demands could also influence the multisensory temporal window of integration. We varied the stimulus onset asynchrony between simple, short-lasting auditory and visual stimuli while participants performed two tasks in separate blocks: a temporal order judgment task that required the discrimination of subtle auditory-visual asynchronies, and a reaction time task to the first incoming stimulus irrespective of its sensory modality. We defined the temporal window of integration as the range of stimulus onset asynchronies where performance was below 75% in the temporal order judgment task, as well as the range of stimulus onset asynchronies where responses showed multisensory facilitation (race model violation) in the reaction time task. In 5 of 11 participants, we observed audio-visual stimulus onset asynchronies where reaction time was significantly accelerated (indicating successful integration in this task) while performance was accurate in the temporal order judgment task (indicating successful segregation in that task). This dissociation suggests that in some participants, the boundaries of the temporal window of integration can adaptively recalibrate in order to optimize performance according to specific task demands. PMID:23951203

Imaging windows for long-term intravital imaging

PubMed Central

Alieva, Maria; Ritsma, Laila; Giedt, Randy J; Weissleder, Ralph; van Rheenen, Jacco

2014-01-01

Intravital microscopy is increasingly used to visualize and quantitate dynamic biological processes at the (sub)cellular level in live animals. By visualizing tissues through imaging windows, individual cells (e.g., cancer, host, or stem cells) can be tracked and studied over a time-span of days to months. Several imaging windows have been developed to access tissues including the brain, superficial fascia, mammary glands, liver, kidney, pancreas, and small intestine among others. Here, we review the development of imaging windows and compare the most commonly used long-term imaging windows for cancer biology: the cranial imaging window, the dorsal skin fold chamber, the mammary imaging window, and the abdominal imaging window. Moreover, we provide technical details, considerations, and trouble-shooting tips on the surgical procedures and microscopy setups for each imaging window and explain different strategies to assure imaging of the same area over multiple imaging sessions. This review aims to be a useful resource for establishing the long-term intravital imaging procedure. PMID:28243510

Imaging windows for long-term intravital imaging: General overview and technical insights.

PubMed

Alieva, Maria; Ritsma, Laila; Giedt, Randy J; Weissleder, Ralph; van Rheenen, Jacco

2014-01-01

Intravital microscopy is increasingly used to visualize and quantitate dynamic biological processes at the (sub)cellular level in live animals. By visualizing tissues through imaging windows, individual cells (e.g., cancer, host, or stem cells) can be tracked and studied over a time-span of days to months. Several imaging windows have been developed to access tissues including the brain, superficial fascia, mammary glands, liver, kidney, pancreas, and small intestine among others. Here, we review the development of imaging windows and compare the most commonly used long-term imaging windows for cancer biology: the cranial imaging window, the dorsal skin fold chamber, the mammary imaging window, and the abdominal imaging window. Moreover, we provide technical details, considerations, and trouble-shooting tips on the surgical procedures and microscopy setups for each imaging window and explain different strategies to assure imaging of the same area over multiple imaging sessions. This review aims to be a useful resource for establishing the long-term intravital imaging procedure.

Photorefractive-based adaptive optical windows

NASA Astrophysics Data System (ADS)

Liu, Yuexin; Yang, Yi; Wang, Bo; Fu, John Y.; Yin, Shizhuo; Guo, Ruyan; Yu, Francis T.

2004-10-01

Optical windows have been widely used in optical spectrographic processing system. In this paper, various window profiles, such as rectangular, triangular, Hamming, Hanning, and Blackman etc., have been investigated in detail, regarding their effect on the generated spectrograms, such as joint time-frequency resolution ΔtΔw, the sidelobe amplitude attenuation etc.. All of these windows can be synthesized in a photorefractive crystal by angular multiplexing holographic technique, which renders the system more adaptive. Experimental results are provided.

Spatial scaling of core and dominant forest cover in the Upper Mississippi and Illinois River floodplains, USA

USGS Publications Warehouse

De Jager, Nathan R.; Rohweder, Jason J.

2011-01-01

Different organisms respond to spatial structure in different terms and across different spatial scales. As a consequence, efforts to reverse habitat loss and fragmentation through strategic habitat restoration ought to account for the different habitat density and scale requirements of various taxonomic groups. Here, we estimated the local density of floodplain forest surrounding each of ~20 million 10-m forested pixels of the Upper Mississippi and Illinois River floodplains by using moving windows of multiple sizes (1–100 ha). We further identified forest pixels that met two local density thresholds: 'core' forest pixels were nested in a 100% (unfragmented) forested window and 'dominant' forest pixels were those nested in a >60% forested window. Finally, we fit two scaling functions to declines in the proportion of forest cover meeting these criteria with increasing window length for 107 management-relevant focal areas: a power function (i.e. self-similar, fractal-like scaling) and an exponential decay function (fractal dimension depends on scale). The exponential decay function consistently explained more variation in changes to the proportion of forest meeting both the 'core' and 'dominant' criteria with increasing window length than did the power function, suggesting that elevation, soil type, hydrology, and human land use constrain these forest types to a limited range of scales. To examine these scales, we transformed the decay constants to measures of the distance at which the probability of forest meeting the 'core' and 'dominant' criteria was cut in half (S 1/2, m). S 1/2 for core forest was typically between ~55 and ~95 m depending on location along the river, indicating that core forest cover is restricted to extremely fine scales. In contrast, half of all dominant forest cover was lost at scales that were typically between ~525 and 750 m, but S 1/2 was as long as 1,800 m. S 1/2 is a simple measure that (1) condenses information derived from multi-scale analyses, (2) allows for comparisons of the amount of forest habitat available to species with different habitat density and scale requirements, and (3) can be used as an index of the spatial continuity of habitat types that do not scale fractally.

Side-by-Side Field Evaluation of Highly Insulating Windows in the PNNL Lab Homes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Widder, Sarah H.; Parker, Graham B.; Baechler, Michael C.

2012-08-01

To examine the energy, air leakage, and thermal performance of highly insulating windows, a field evaluation was undertaken in a matched pair of all-electric, factory-built “Lab Homes” located on the Pacific Northwest National Laboratory (PNNL) campus in Richland, Washington. The “baseline” Lab Home B was retrofitted with “standard” double-pane clear aluminum-frame slider windows and patio doors, while the “experimental” Lab Home A was retrofitted with Jeld-Wen® triple-pane vinyl-frame slider windows and patio doors with a U-factor of 0.2 and solar heat gain coefficient of 0.19. To assess the window, the building shell air leakage, energy use, and interior temperatures ofmore » each home were compared during the 2012 winter heating and summer cooling seasons. The measured energy savings in Lab Home B averaged 5,821 watt-hours per day (Wh/day) during the heating season and 6,518 Wh/day during the cooling season. The overall whole-house energy savings of Lab Home B compared to Lab Home A are 11.6% ± 1.53% for the heating season and 18.4 ± 2.06% for the cooling season for identical occupancy conditions with no window coverings deployed. Extrapolating these energy savings numbers based on typical average heating degree days and cooling degree days per year yields an estimated annual energy savings of 12.2%, or 1,784 kWh/yr. The data suggest that highly insulating windows are an effective energy-saving measure that should be considered for high-performance new homes and in existing retrofits. However, the cost effectiveness of the measure, as determined by the simple payback period, suggests that highly insulating window costs continue to make windows difficult to justify on a cost basis alone. Additional reductions in costs via improvements in manufacturing and/or market penetration that continue to drive down costs will make highly insulating windows much more viable as a cost-effective energy efficiency measure. This study also illustrates that highly insulating windows have important impacts on peak load, occupant comfort, and condensation potential, which are not captured in the energy savings calculation. More consistent and uniform interior temperature distributions suggest that highly insulated windows, as part of a high performance building envelope, may enable more centralized duct design and downsized HVAC systems. Shorter, more centralized duct systems and smaller HVAC systems to yield additional cost savings, making highly insulating windows more cost effective as part of a package of new construction or retrofit measures which achieve significant reductions in home energy use.« less

Managing fire and fuels in a warmer climate

Treesearch

David L. Peterson

2010-01-01

This historical perspective on fire provides a window into the future of fire in the Pacific Northwest. Although fire will always be more common in the interior portion of the region, a warmer climate could bring more fire to the westside of the Cascade Range where summers are typically dry and will probably become drier. If future climate resembles the climate now...

The Shock and Vibration Bulletin. Part 2. Ship Shock, Shock and Blast and Ground Shock

DTIC Science & Technology

1984-06-01

followee As built, structures have a maximumSsomu of Inelastic respose whic they can ::• Governina Failure Mode Approximate Failure itai fielsi epne ih...inside surface of window "panes. Typical films are about 0.002 to Charts are presented in Figures 2 to 16 for 0.004 inch thick polyester with a self

¿Qué Pasa? Are ELL Students Remaining in English Learning Classes Too Long?

ERIC Educational Resources Information Center

Flores, Edward; Painter, Gary; Pachon, Harry

2009-01-01

This new study by the Tomás Rivera Policy Institute (TRPI) demonstrates that English Language Learners (ELLs) who learn English at school can do better academically than native English speakers, and that the window for mastering the English language is wider than previously thought. Typically ELLs perform at lower levels than their English-fluent…

Debugging classification and anti-debugging strategies

NASA Astrophysics Data System (ADS)

Gao, Shang; Lin, Qian; Xia, Mingyuan; Yu, Miao; Qi, Zhengwei; Guan, Haibing

2011-12-01

Debugging, albeit useful for software development, is also a double-edge sword since it could also be exploited by malicious attackers. This paper analyzes the prevailing debuggers and classifies them into 4 categories based on the debugging mechanism. Furthermore, as an opposite, we list 13 typical anti-debugging strategies adopted in Windows. These methods intercept specific execution points which expose the diagnostic behavior of debuggers.

Extender for securing a closure

DOEpatents

Thomas, II, Patrick A.

2012-10-02

An apparatus for securing a closure such as door or a window that opens and closes by movement relative to a fixed structure such as a wall or a floor. Many embodiments provide a device for relocating a padlock from its normal location where it secures a fastener (such as a hasp) to a location for the padlock that is more accessible for locking and unlocking the padlock. Typically an extender is provided, where the extender has a hook at a first end that is disposed through the eye of the staple of the hasp, and at an opposing second end the extender has an annulus, such as a hole in the extender or a loop or ring affixed to the extender. The shackle of the padlock may be disposed through the annulus and may be disposed through the eye of a second staple to secure the door or window in a closed or open position. Some embodiments employ a rigid sheath to enclose at least a portion of the extender. Typically the rigid sheath has an open state where the hook is exposed outside the sheath and a closed state where the hook is disposed within the sheath.

Noise normalization and windowing functions for VALIDAR in wind parameter estimation

NASA Astrophysics Data System (ADS)

Beyon, Jeffrey Y.; Koch, Grady J.; Li, Zhiwen

2006-05-01

The wind parameter estimates from a state-of-the-art 2-μm coherent lidar system located at NASA Langley, Virginia, named VALIDAR (validation lidar), were compared after normalizing the noise by its estimated power spectra via the periodogram and the linear predictive coding (LPC) scheme. The power spectra and the Doppler shift estimates were the main parameter estimates for comparison. Different types of windowing functions were implemented in VALIDAR data processing algorithm and their impact on the wind parameter estimates was observed. Time and frequency independent windowing functions such as Rectangular, Hanning, and Kaiser-Bessel and time and frequency dependent apodized windowing function were compared. The briefing of current nonlinear algorithm development for Doppler shift correction subsequently follows.

'DNA Strider': a 'C' program for the fast analysis of DNA and protein sequences on the Apple Macintosh family of computers.

PubMed Central

Marck, C

1988-01-01

DNA Strider is a new integrated DNA and Protein sequence analysis program written with the C language for the Macintosh Plus, SE and II computers. It has been designed as an easy to learn and use program as well as a fast and efficient tool for the day-to-day sequence analysis work. The program consists of a multi-window sequence editor and of various DNA and Protein analysis functions. The editor may use 4 different types of sequences (DNA, degenerate DNA, RNA and one-letter coded protein) and can handle simultaneously 6 sequences of any type up to 32.5 kB each. Negative numbering of the bases is allowed for DNA sequences. All classical restriction and translation analysis functions are present and can be performed in any order on any open sequence or part of a sequence. The main feature of the program is that the same analysis function can be repeated several times on different sequences, thus generating multiple windows on the screen. Many graphic capabilities have been incorporated such as graphic restriction map, hydrophobicity profile and the CAI plot- codon adaptation index according to Sharp and Li. The restriction sites search uses a newly designed fast hexamer look-ahead algorithm. Typical runtime for the search of all sites with a library of 130 restriction endonucleases is 1 second per 10,000 bases. The circular graphic restriction map of the pBR322 plasmid can be therefore computed from its sequence and displayed on the Macintosh Plus screen within 2 seconds and its multiline restriction map obtained in a scrolling window within 5 seconds. PMID:2832831

Efficient full-chip SRAF placement using machine learning for best accuracy and improved consistency

NASA Astrophysics Data System (ADS)

Wang, Shibing; Baron, Stanislas; Kachwala, Nishrin; Kallingal, Chidam; Sun, Dezheng; Shu, Vincent; Fong, Weichun; Li, Zero; Elsaid, Ahmad; Gao, Jin-Wei; Su, Jing; Ser, Jung-Hoon; Zhang, Quan; Chen, Been-Der; Howell, Rafael; Hsu, Stephen; Luo, Larry; Zou, Yi; Zhang, Gary; Lu, Yen-Wen; Cao, Yu

2018-03-01

Various computational approaches from rule-based to model-based methods exist to place Sub-Resolution Assist Features (SRAF) in order to increase process window for lithography. Each method has its advantages and drawbacks, and typically requires the user to make a trade-off between time of development, accuracy, consistency and cycle time. Rule-based methods, used since the 90 nm node, require long development time and struggle to achieve good process window performance for complex patterns. Heuristically driven, their development is often iterative and involves significant engineering time from multiple disciplines (Litho, OPC and DTCO). Model-based approaches have been widely adopted since the 20 nm node. While the development of model-driven placement methods is relatively straightforward, they often become computationally expensive when high accuracy is required. Furthermore these methods tend to yield less consistent SRAFs due to the nature of the approach: they rely on a model which is sensitive to the pattern placement on the native simulation grid, and can be impacted by such related grid dependency effects. Those undesirable effects tend to become stronger when more iterations or complexity are needed in the algorithm to achieve required accuracy. ASML Brion has developed a new SRAF placement technique on the Tachyon platform that is assisted by machine learning and significantly improves the accuracy of full chip SRAF placement while keeping consistency and runtime under control. A Deep Convolutional Neural Network (DCNN) is trained using the target wafer layout and corresponding Continuous Transmission Mask (CTM) images. These CTM images have been fully optimized using the Tachyon inverse mask optimization engine. The neural network generated SRAF guidance map is then used to place SRAF on full-chip. This is different from our existing full-chip MB-SRAF approach which utilizes a SRAF guidance map (SGM) of mask sensitivity to improve the contrast of optical image at the target pattern edges. In this paper, we demonstrate that machine learning assisted SRAF placement can achieve a superior process window compared to the SGM model-based SRAF method, while keeping the full-chip runtime affordable, and maintain consistency of SRAF placement . We describe the current status of this machine learning assisted SRAF technique and demonstrate its application to full chip mask synthesis and discuss how it can extend the computational lithography roadmap.

Rheological and micro-Raman time-series characterization of enzyme sol–gel solution toward morphological control of electrospun fibers

PubMed Central

Oriero, Dennis A; Weakley, Andrew T; Aston, D Eric

2012-01-01

Rheological and micro-Raman time-series characterizations were used to investigate the chemical evolutionary changes of silica sol–gel mixtures for electrospinning fibers to immobilize an enzyme (tyrosinase). Results of dynamic rheological measurements agreed with the expected structural transitions associated with reacting sol–gel systems. The electrospinning sols exhibited shear-thinning behavior typical of a power law model. Ultrafine (200–300 nm diameter) fibers were produced at early and late times within the reaction window of approximately one hour from initial mixing of sol solutions with and without enzyme; diameter distributions of these fibers showed much smaller deviations than expected. The enzyme markedly increased magnitudes of both elastic and viscous moduli but had no significant impact on final fiber diameters, suggesting that the shear-thinning behavior of both sol–gel mixtures is dominant in the fiber elongation process. The time course and scale for the electrospinning batch fabrication show strong correlations between the magnitudes in rheological property changes over time and the chemical functional group evolution obtained from micro-Raman time-series analysis of the reacting sol–gel systems. PMID:27877486

Application of MEMS-based x-ray optics as tuneable nanosecond choppers

NASA Astrophysics Data System (ADS)

Chen, Pice; Walko, Donald A.; Jung, Il Woong; Li, Zhilong; Gao, Ya; Shenoy, Gopal K.; Lopez, Daniel; Wang, Jin

2017-08-01

Time-resolved synchrotron x-ray measurements often rely on using a mechanical chopper to isolate a set of x-ray pulses. We have started the development of micro electromechanical systems (MEMS)-based x-ray optics, as an alternate method to manipulate x-ray beams. In the application of x-ray pulse isolation, we recently achieved a pulse-picking time window of half a nanosecond, which is more than 100 times faster than mechanical choppers can achieve. The MEMS device consists of a comb-drive silicon micromirror, designed for efficiently diffracting an x-ray beam during oscillation. The MEMS devices were operated in Bragg geometry and their oscillation was synchronized to x-ray pulses, with a frequency matching subharmonics of the cycling frequency of x-ray pulses. The microscale structure of the silicon mirror in terms of the curvature and the quality of crystallinity ensures a narrow angular spread of the Bragg reflection. With the discussion of factors determining the diffractive time window, this report showed our approaches to narrow down the time window to half a nanosecond. The short diffractive time window will allow us to select single x-ray pulse out of a train of pulses from synchrotron radiation facilities.

Mapping conduction velocity of early embryonic hearts with a robust fitting algorithm

PubMed Central

Gu, Shi; Wang, Yves T; Ma, Pei; Werdich, Andreas A; Rollins, Andrew M; Jenkins, Michael W

2015-01-01

Cardiac conduction maturation is an important and integral component of heart development. Optical mapping with voltage-sensitive dyes allows sensitive measurements of electrophysiological signals over the entire heart. However, accurate measurements of conduction velocity during early cardiac development is typically hindered by low signal-to-noise ratio (SNR) measurements of action potentials. Here, we present a novel image processing approach based on least squares optimizations, which enables high-resolution, low-noise conduction velocity mapping of smaller tubular hearts. First, the action potential trace measured at each pixel is fit to a curve consisting of two cumulative normal distribution functions. Then, the activation time at each pixel is determined based on the fit, and the spatial gradient of activation time is determined with a two-dimensional (2D) linear fit over a square-shaped window. The size of the window is adaptively enlarged until the gradients can be determined within a preset precision. Finally, the conduction velocity is calculated based on the activation time gradient, and further corrected for three-dimensional (3D) geometry that can be obtained by optical coherence tomography (OCT). We validated the approach using published activation potential traces based on computer simulations. We further validated the method by adding artificially generated noise to the signal to simulate various SNR conditions using a curved simulated image (digital phantom) that resembles a tubular heart. This method proved to be robust, even at very low SNR conditions (SNR = 2-5). We also established an empirical equation to estimate the maximum conduction velocity that can be accurately measured under different conditions (e.g. sampling rate, SNR, and pixel size). Finally, we demonstrated high-resolution conduction velocity maps of the quail embryonic heart at a looping stage of development. PMID:26114034

Windows of sensitivity to toxic chemicals in the motor effects development.

PubMed

Ingber, Susan Z; Pohl, Hana R

2016-02-01

Many chemicals currently used are known to elicit nervous system effects. In addition, approximately 2000 new chemicals introduced annually have not yet undergone neurotoxicity testing. This review concentrated on motor development effects associated with exposure to environmental neurotoxicants to help identify critical windows of exposure and begin to assess data needs based on a subset of chemicals thoroughly reviewed by the Agency for Toxic Substances and Disease Registry (ATSDR) in Toxicological Profiles and Addenda. Multiple windows of sensitivity were identified that differed based on the maturity level of the neurological system at the time of exposure, as well as dose and exposure duration. Similar but distinct windows were found for both motor activity (GD 8-17 [rats], GD 12-14 and PND 3-10 [mice]) and motor function performance (insufficient data for rats, GD 12-17 [mice]). Identifying specific windows of sensitivity in animal studies was hampered by study designs oriented towards detection of neurotoxicity that occurred at any time throughout the developmental process. In conclusion, while this investigation identified some critical exposure windows for motor development effects, it demonstrates a need for more acute duration exposure studies based on neurodevelopmental windows, particularly during the exposure periods identified in this review. Published by Elsevier Inc.

Windows of sensitivity to toxic chemicals in the motor effects development✩

PubMed Central

Ingber, Susan Z.; Pohl, Hana R.

2017-01-01

Many chemicals currently used are known to elicit nervous system effects. In addition, approximately 2000 new chemicals introduced annually have not yet undergone neurotoxicity testing. This review concentrated on motor development effects associated with exposure to environmental neurotoxicants to help identify critical windows of exposure and begin to assess data needs based on a subset of chemicals thoroughly reviewed by the Agency for Toxic Substances and Disease Registry (ATSDR) in Toxicological Profiles and Addenda. Multiple windows of sensitivity were identified that differed based on the maturity level of the neurological system at the time of exposure, as well as dose and exposure duration. Similar but distinct windows were found for both motor activity (GD 8–17 [rats], GD 12–14 and PND 3–10 [mice]) and motor function performance (insufficient data for rats, GD 12–17 [mice]). Identifying specific windows of sensitivity in animal studies was hampered by study designs oriented towards detection of neurotoxicity that occurred at any time throughout the developmental process. In conclusion, while this investigation identified some critical exposure windows for motor development effects, it demonstrates a need for more acute duration exposure studies based on neurodevelopmental windows, particularly during the exposure periods identified in this review. PMID:26686904

Simple Estimation of Incident HIV Infection Rates in Notification Cohorts Based on Window Periods of Algorithms for Evaluation of Line-Immunoassay Result Patterns

PubMed Central

Schüpbach, Jörg; Gebhardt, Martin D.; Scherrer, Alexandra U.; Bisset, Leslie R.; Niederhauser, Christoph; Regenass, Stephan; Yerly, Sabine; Aubert, Vincent; Suter, Franziska; Pfister, Stefan; Martinetti, Gladys; Andreutti, Corinne; Klimkait, Thomas; Brandenberger, Marcel; Günthard, Huldrych F.

2013-01-01

Background Tests for recent infections (TRIs) are important for HIV surveillance. We have shown that a patient's antibody pattern in a confirmatory line immunoassay (Inno-Lia) also yields information on time since infection. We have published algorithms which, with a certain sensitivity and specificity, distinguish between incident (< = 12 months) and older infection. In order to use these algorithms like other TRIs, i.e., based on their windows, we now determined their window periods. Methods We classified Inno-Lia results of 527 treatment-naïve patients with HIV-1 infection < = 12 months according to incidence by 25 algorithms. The time after which all infections were ruled older, i.e. the algorithm's window, was determined by linear regression of the proportion ruled incident in dependence of time since infection. Window-based incident infection rates (IIR) were determined utilizing the relationship ‘Prevalence  =  Incidence x Duration’ in four annual cohorts of HIV-1 notifications. Results were compared to performance-based IIR also derived from Inno-Lia results, but utilizing the relationship ‘incident  =  true incident + false incident’ and also to the IIR derived from the BED incidence assay. Results Window periods varied between 45.8 and 130.1 days and correlated well with the algorithms' diagnostic sensitivity (R2 = 0.962; P<0.0001). Among the 25 algorithms, the mean window-based IIR among the 748 notifications of 2005/06 was 0.457 compared to 0.453 obtained for performance-based IIR with a model not correcting for selection bias. Evaluation of BED results using a window of 153 days yielded an IIR of 0.669. Window-based IIR and performance-based IIR increased by 22.4% and respectively 30.6% in 2008, while 2009 and 2010 showed a return to baseline for both methods. Conclusions IIR estimations by window- and performance-based evaluations of Inno-Lia algorithm results were similar and can be used together to assess IIR changes between annual HIV notification cohorts. PMID:23990968

75 FR 11889 - Request for Comments on Proposed NIH, AHRQ and CDC Process Change for Electronic Submission of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-12

... impact of eliminating the correction window from the electronic grant application submission process on... process a temporary error correction window to ensure a smooth and successful transition for applicants. This window provides applicants a period of time beyond the grant application due date to correct any...

Human Mars Mission: Launch Window from Earth Orbit. Pt. 1

NASA Technical Reports Server (NTRS)

Young, Archie

1999-01-01

The determination of orbital window characteristics is of major importance in the analysis of human interplanetary missions and systems. The orbital launch window characteristics are directly involved in the selection of mission trajectories, the development of orbit operational concepts, and the design of orbital launch systems. The orbital launch window problem arises because of the dynamic nature of the relative geometry between outgoing (departure) asymptote of the hyperbolic escape trajectory and the earth parking orbit. The orientation of the escape hyperbola asymptotic relative to the earth is a function of time. The required hyperbola energy level also varies with time. In addition, the inertial orientation of the parking orbit is a function of time because of the perturbations caused by the Earth's oblateness. Thus, a coplanar injection onto the escape hyperbola can be made only at a point in time when the outgoing escape asymptote is contained by the plane of parking orbit. Even though this condition may be planned as a nominal situation, it will not generally represent the more probable injection geometry. The general case of an escape injection maneuver performed at a time other than the coplanar time will involve both a path angle and plane change and, therefore, a delta V penalty. Usually, because of the delta V penalty the actual departure injection window is smaller in duration than that determined by energy requirement alone. This report contains the formulation, characteristics, and test cases for five different launch window modes for Earth orbit. These modes are: 1) One impulsive maneuver from a Highly Elliptical Orbit (HEO); 2) Two impulsive maneuvers from a Highly Elliptical Orbit (HEO); 3) One impulsive maneuver from a Low Earth Orbit (LEO); 4) Two impulsive maneuvers form LEO; and 5) Three impulsive maneuvers form LEO. The formulation of these five different launch window modes provides a rapid means of generating realistic parametric data for space exploration studies. Also the formulation provides vector and geometrical data sufficient for use as a good starting point in detail trajectory analysis based on calculus of variations, steepest descent, or parameter optimization program techniques.

Human Exploration Missions Study Launch Window from Earth Orbit

NASA Technical Reports Server (NTRS)

Young, Archie

2001-01-01

The determination of orbital launch window characteristics is of major importance in the analysis of human interplanetary missions and systems. The orbital launch window characteristics are directly involved in the selection of mission trajectories, the development of orbit operational concepts, and the design of orbital launch systems. The orbital launch window problem arises because of the dynamic nature of the relative geometry between outgoing (departure) asymptote of the hyperbolic escape trajectory and the earth parking orbit. The orientation of the escape hyperbola asymptotic relative to earth is a function of time. The required hyperbola energy level also varies with time. In addition, the inertial orientation of the parking orbit is a function of time because of the perturbations caused by the Earth's oblateness. Thus, a coplanar injection onto the escape hyperbola can be made only at a point in time when the outgoing escape asymptote is contained by the plane of parking orbit. Even though this condition may be planned as a nominal situation, it will not generally represent the more probable injection geometry. The general case of an escape injection maneuver performed at a time other than the coplanar time will involve both a path angle and plane change and, therefore, a Delta(V) penalty. Usually, because of the Delta(V) penalty the actual departure injection window is smaller in duration than that determined by energy requirement alone. This report contains the formulation, characteristics, and test cases for five different launch window modes for Earth orbit. These modes are: (1) One impulsive maneuver from a Low Earth Orbit (LEO), (2) Two impulsive maneuvers from LEO, (3) Three impulsive maneuvers from LEO, (4) One impulsive maneuvers from a Highly Elliptical Orbit (HEO), (5) Two impulsive maneuvers from a Highly Elliptical Orbit (HEO) The formulation of these five different launch window modes provides a rapid means of generating realistic parametric data for space exploration studies. Also the formulation provides vector and geometrical data sufficient for use as a good starting point in detail trajectory analysis based on calculus of variations, steepest descent, or parameter optimization program techniques.

GlastCam: A Telemetry-Driven Spacecraft Visualization Tool

NASA Technical Reports Server (NTRS)

Stoneking, Eric T.; Tsai, Dean

2009-01-01

Developed for the GLAST project, which is now the Fermi Gamma-ray Space Telescope, GlastCam software ingests telemetry from the Integrated Test and Operations System (ITOS) and generates four graphical displays of geometric properties in real time, allowing visual assessment of the attitude, configuration, position, and various cross-checks. Four windows are displayed: a "cam" window shows a 3D view of the satellite; a second window shows the standard position plot of the satellite on a Mercator map of the Earth; a third window displays star tracker fields of view, showing which stars are visible from the spacecraft in order to verify star tracking; and the fourth window depicts

Scala tympani cochleostomy I: results of a survey.

PubMed

Adunka, Oliver F; Buchman, Craig A

2007-12-01

To assess current surgical techniques for scala tympani cochlear implantation among North American surgeons. A survey was distributed to all cochlear implant surgeons participating in the 2006 William House Cochlear Implant Study Group in Toronto, Canada. Participants were asked to anonymously identify their routine surgical practices. Images of trans-facial recess approaches to the round window and cochlear promontory were used in a multiple-choice fashion to assess the surgeon's typical exposure and cochleostomy location. Returned questionnaires were electronically processed and evaluated. Fifty-five (75%) of 73 returned surveys had adequate data validity and availability. Landmark identification and preferred cochleostomy locations varied greatly. About 20% of surgeons selected cochleostomy locations superior to the round window membrane. Cochleostomy size and location appeared to be influenced by surgical experience and whether or not the round window overhang was drilled off. This survey clearly documents marked variations in surgical techniques for scala tympani cochlear implantation. Future studies should more clearly define the surgical anatomy of this region for appropriate placement of a scala tympani cochleostomy. These findings may ultimately have an impact on hearing and neural preservation cochlear implant surgeries.

BIPV-Powered Smart Windows Utilizing Photovoltaic and Electrochromic Devices

PubMed Central

Ma, Rong-Hua; Chen, Yu-Chia

2012-01-01

A BIPV-powered smart window comprising a building-integrated photovoltaic (BIPV) panel and an all-solid-state electrochromic (EC) stack is proposed. In the proposed device, the output voltage of the BIPV panel varies in accordance with the intensity of the incident light and is modulated in such a way as to generate the EC stack voltage required to maintain the indoor illuminance within a specified range. Two different EC stacks are fabricated and characterized, namely one stack comprising ITO/WO3/Ta2O5/ITO and one stack comprising ITO/WO3/lithium-polymer electrolyte/ITO. It is shown that of the two stacks, the ITO/WO3/lithium-polymer electrolyte/ITO stack has a larger absorptance (i.e., approximately 99% at a driving voltage of 3.5 V). The experimental results show that the smart window incorporating an ITO/WO3/lithium-polymer electrolyte/ITO stack with an electrolyte thickness of 1.0 μm provides an indoor illuminance range of 750–1,500 Lux under typical summertime conditions in Taiwan. PMID:22368474

Windows Into the Real World From a Virtual Globe

NASA Astrophysics Data System (ADS)

Rich, J.; Urban-Rich, J.

2007-12-01

Virtual globes such as Google Earth can be great tools for learning about the geographical variation of the earth. The key to virtual globes is the use of satellite imagery to provide a highly accurate view of the earth's surface. However, because the images are not updated regularly, variations in climate and vegetation over time can not be easily seen. In order to enhance the view of the earth and observe these changes by region and over time we are working to add near real time "windows" into the real world from a virtual globe. For the past 4 years we have been installing web cameras in areas of the world that will provide long term monitoring of global changes. By archiving hourly images from arctic, temperate and tropical regions we are creating a visual data set that is already beginning to tell the story of climate variability. The cameras are currently installed in 10 elementary schools in 3 countries and show the student's view out each window. The Windows Around the World program (http://www.WindowsAroundTheWorld.org) uses the images from these cameras to help students gain a better understanding of earth process and variability in climate and vegetation between different regions and over time. Previously we have used standard web based technologies such as DHTML and AJAX to provide near real-time access to these images and also provide enhanced functionality such as dynamic time lapse movies that allow users to see changes over months, days or hours up to the current hour (http://www.windowsaroundtheworld.org/north_america.aspx). We have integrated the camera images from Windows Around the World into Google Earth. Through network links and models we are creating a way for students to "fly" to another school in the program and see what the current view is out the window. By using a model as a screen, the image can be viewed from the same direction as the students who are sitting in a classroom at the participating school. Once at the school, visiting students can move around the area in three dimensions and gain a better understanding of what they are seeing out the window. Currently time-lapse images can be viewed at a lower resolution for all schools on the globe or when flying into an individual school, higher resolution time-lapse images can be seen. The observation of shadows, precipitation, movement of the sun and changes in vegetation allows the viewer to gain a better understanding of how the earth works and how the environment changes between regions and over time. World.org

Effects of mixing eggs of different initial incubation time on the hatching pattern, chick embryonic development and post-hatch performance.

PubMed

Zhong, Zhentao; Yu, Yue; Jin, Shufang; Pan, Jinming

2018-01-01

The hatch window that varies from 24 to 48 h is known to influence post-hatch performance of chicks. A narrow hatch window is needed for commercial poultry industry to acquire a high level of uniformity of chick quality. Hatching synchronization observed in avian species presents possibilities in altering hatch window in artificial incubation. Layer eggs which were laid on the same day by a single breeder flock and stored for no more than two days started incubation 12 h apart to obtain developmental distinction. The eggs of different initial incubation time were mixed as rows adjacent to rows on day 12 of incubation. During the hatching period (since day 18), hatching time of individual eggs and hatch window were obtained by video recordings. Embryonic development (day 18 and 20) and post-hatch performance up to day 7 were measured. The manipulation of mixing eggs of different initial incubation time shortened the hatch window of late incubated eggs in the manipulated group by delaying the onset of hatching process, and improved the hatchability. Compared to the control groups, chick embryos or chicks in the egg redistribution group showed no significant difference in embryonic development and post-hatch performance up to day 7. We have demonstrated that eggs that were incubated with advanced eggs performed a narrow spread of hatch with higher hatchability, normal embryonic development as well as unaffected chick quality. This specific manipulation is applicable in industrial poultry production to shorten hatch window and improve the uniformity of chick quality.

Seismic signal time-frequency analysis based on multi-directional window using greedy strategy

NASA Astrophysics Data System (ADS)

Chen, Yingpin; Peng, Zhenming; Cheng, Zhuyuan; Tian, Lin

2017-08-01

Wigner-Ville distribution (WVD) is an important time-frequency analysis technology with a high energy distribution in seismic signal processing. However, it is interfered by many cross terms. To suppress the cross terms of the WVD and keep the concentration of its high energy distribution, an adaptive multi-directional filtering window in the ambiguity domain is proposed. This begins with the relationship of the Cohen distribution and the Gabor transform combining the greedy strategy and the rotational invariance property of the fractional Fourier transform in order to propose the multi-directional window, which extends the one-dimensional, one directional, optimal window function of the optimal fractional Gabor transform (OFrGT) to a two-dimensional, multi-directional window in the ambiguity domain. In this way, the multi-directional window matches the main auto terms of the WVD more precisely. Using the greedy strategy, the proposed window takes into account the optimal and other suboptimal directions, which also solves the problem of the OFrGT, called the local concentration phenomenon, when encountering a multi-component signal. Experiments on different types of both the signal models and the real seismic signals reveal that the proposed window can overcome the drawbacks of the WVD and the OFrGT mentioned above. Finally, the proposed method is applied to a seismic signal's spectral decomposition. The results show that the proposed method can explore the space distribution of a reservoir more precisely.

Air transparent soundproof window

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Sang-Hoon, E-mail: shkim@mmu.ac.kr; Lee, Seong-Hyun

2014-11-15

A soundproof window or wall which is transparent to airflow is presented. The design is based on two wave theories: the theory of diffraction and the theory of acoustic metamaterials. It consists of a three-dimensional array of strong diffraction-type resonators with many holes centered on each individual resonator. The negative effective bulk modulus of the resonators produces evanescent wave, and at the same time the air holes with subwavelength diameter existed on the surfaces of the window for macroscopic air ventilation. The acoustic performance levels of two soundproof windows with air holes of 20mm and 50mm diameters were measured. Themore » sound level was reduced by about 30 - 35dB in the frequency range of 400 - 5,000Hz with the 20mm window, and by about 20 - 35dB in the frequency range of 700 - 2,200Hz with the 50mm window. Multi stop-band was created by the multi-layers of the window. The attenuation length or the thickness of the window was limited by background noise. The effectiveness of the soundproof window with airflow was demonstrated by a real installation.« less

Watching conformational- and photo-dynamics of single fluorescent proteins in solution.

PubMed

Goldsmith, Randall H; Moerner, W E

2010-03-01

Observing the dynamics of single biomolecules over prolonged time periods is difficult to achieve without significantly altering the molecule through immobilization. It can, however, be accomplished using the Anti-Brownian ELectrokinetic (ABEL) Trap, which allows extended investigation of solution-phase biomolecules - without immobilization -through real-time electrokinetic feedback. Here we apply the ABEL trap to study an important photosynthetic antenna protein, Allophycocyanin (APC). The technique allows the observation of single molecules of solution-phase APC for more than one second. We observe a complex relationship between fluorescence intensity and lifetime that cannot be explained by simple static kinetic models. Light-induced conformational changes are shown to occur and evidence is obtained for fluctuations in the spontaneous emission lifetime, which is typically assumed to be constant. Our methods provide a new window into the dynamics of fluorescent proteins and the observations are relevant for the interpretation of in vivo single-molecule imaging experiments, bacterial photosynthetic regulation, and biomaterials for solar energy harvesting.

Extreme multi-basin flooding linked with extra-tropical cyclones

NASA Astrophysics Data System (ADS)

De Luca, Paolo; Hillier, John K.; Wilby, Robert L.; Quinn, Nevil W.; Harrigan, Shaun

2017-11-01

Fluvial floods are typically investigated as ‘events’ at the single basin-scale, hence flood management authorities may underestimate the threat of flooding across multiple basins driven by large-scale and nearly concurrent atmospheric event(s). We pilot a national-scale statistical analysis of the spatio-temporal characteristics of extreme multi-basin flooding (MBF) episodes, using peak river flow data for 260 basins in Great Britain (1975-2014), a sentinel region for storms impacting northwest and central Europe. During the most widespread MBF episode, 108 basins (~46% of the study area) recorded annual maximum (AMAX) discharge within a 16 day window. Such episodes are associated with persistent cyclonic and westerly atmospheric circulations, atmospheric rivers, and precipitation falling onto previously saturated ground, leading to hydrological response times <40 h and documented flood impacts. Furthermore, peak flows tend to occur after 0-13 days of very severe gales causing combined and spatially-distributed, yet differentially time-lagged, wind and flood damages. These findings have implications for emergency responders, insurers and contingency planners worldwide.

Watching conformational- and photo-dynamics of single fluorescent proteins in solution

PubMed Central

Goldsmith, Randall H.

2010-01-01

Observing the dynamics of single biomolecules over prolonged time periods is difficult to achieve without significantly altering the molecule through immobilization. It can, however, be accomplished using the Anti-Brownian ELectrokinetic (ABEL) Trap, which allows extended investigation of solution-phase biomolecules - without immobilization -through real-time electrokinetic feedback. Here we apply the ABEL trap to study an important photosynthetic antenna protein, Allophycocyanin (APC). The technique allows the observation of single molecules of solution-phase APC for more than one second. We observe a complex relationship between fluorescence intensity and lifetime that cannot be explained by simple static kinetic models. Light-induced conformational changes are shown to occur and evidence is obtained for fluctuations in the spontaneous emission lifetime, which is typically assumed to be constant. Our methods provide a new window into the dynamics of fluorescent proteins and the observations are relevant for the interpretation of in vivo single-molecule imaging experiments, bacterial photosynthetic regulation, and biomaterials for solar energy harvesting. PMID:20625479

Watching conformational- and photodynamics of single fluorescent proteins in solution

NASA Astrophysics Data System (ADS)

Goldsmith, Randall H.; Moerner, W. E.

2010-03-01

Observing the dynamics of single biomolecules over prolonged time periods is difficult to achieve without significantly altering the molecule through immobilization. It can, however, be accomplished using the anti-Brownian electrokinetic trap, which allows extended investigation of solution-phase biomolecules-without immobilization-through real-time electrokinetic feedback. Here we apply the trap to study an important photosynthetic antenna protein, allophycocyanin. The technique allows the observation of single molecules of solution-phase allophycocyanin for more than one second. We observe a complex relationship between fluorescence intensity and lifetime that cannot be explained by simple static kinetic models. Light-induced conformational changes are shown to occur and evidence is obtained for fluctuations in the spontaneous emission lifetime, which is typically assumed to be constant. Our methods provide a new window into the dynamics of fluorescent proteins and the observations are relevant for the interpretation of in vivo single-molecule imaging experiments, bacterial photosynthetic regulation and biomaterials for solar energy harvesting.

ScreenMasker: An Open-source Gaze-contingent Screen Masking Environment.

PubMed

Orlov, Pavel A; Bednarik, Roman

2016-09-01

The moving-window paradigm, based on gazecontingent technic, traditionally used in a studies of the visual perceptual span. There is a strong demand for new environments that could be employed by non-technical researchers. We have developed an easy-to-use tool with a graphical user interface (GUI) allowing both execution and control of visual gaze-contingency studies. This work describes ScreenMasker, an environment that allows create gaze-contingent textured displays used together with stimuli presentation software. ScreenMasker has an architecture that meets the requirements of low-latency real-time eye-movement experiments. It also provides a variety of settings and functions. Effective rendering times and performance are ensured by means of GPU processing under CUDA technology. Performance tests show ScreenMasker's latency to be 67-74 ms on a typical office computer, and high-end 144-Hz screen latencies of about 25-28 ms. ScreenMasker is an open-source system distributed under the GNU Lesser General Public License and is available at https://github.com/PaulOrlov/ScreenMasker .

Alternative Fuels Data Center: Schwan's Home Service Delivers With

Science.gov Websites

distribute products across the United States. For information about this project, contact Twin Cities Clean Cities Coalition. Download QuickTime Video QuickTime (.mov) Download Windows Media Video Windows Media (.wmv) Video Download Help Text version See more videos provided by Clean Cities TV and FuelEconomy.gov

Displaying Special Characters and Symbols in Computer-Controlled Reaction Time Experiments.

ERIC Educational Resources Information Center

Friel, Brian M.; Kennison, Shelia M.

A procedure for using MEL2 (Version 2.0 of Microcomputer Experimental Laboratory) and FontWINDOW to present special characters and symbols in computer-controlled reaction time experiments is described. The procedure permits more convenience and flexibility than in tachistocopic and projection techniques. FontWINDOW allows researchers to design…

Attosecond light sources in the water window

NASA Astrophysics Data System (ADS)

Ren, Xiaoming; Li, Jie; Yin, Yanchun; Zhao, Kun; Chew, Andrew; Wang, Yang; Hu, Shuyuan; Cheng, Yan; Cunningham, Eric; Wu, Yi; Chini, Michael; Chang, Zenghu

2018-02-01

As a compact and burgeoning alternative to synchrotron radiation and free-electron lasers, high harmonic generation (HHG) has proven its superiority in static and time-resolved extreme ultraviolet spectroscopy for the past two decades and has recently gained many interests and successes in generating soft x-ray emissions covering the biologically important water window spectral region. Unlike synchrotron and free-electron sources, which suffer from relatively long pulse width or large time jitter, soft x-ray sources from HHG could offer attosecond time resolution and be synchronized with their driving field to investigate time-resolved near edge absorption spectroscopy, which could reveal rich structural and dynamical information of the interrogated samples. In this paper, we review recent progresses on generating and characterizing attosecond light sources in the water window region. We show our development of an energetic, two-cycle, carrier-envelope phase stable laser source at 1.7 μm and our achievement in producing a 53 as soft x-ray pulse covering the carbon K-edge in the water window. Such source paves the ways for the next generation x-ray spectroscopy with unprecedented temporal resolution.

Android Video Streaming

DTIC Science & Technology

2014-05-01

natural choice. In this document, we describe several aspects of video streaming and the challenges of performing video streaming between Android-based...client application was needed. Typically something like VideoLAN Client ( VLC ) is used for this purpose in a desktop environment. However, while VLC is...a very mature application on Windows and Linux, VLC for Android is still in a beta testing phase, and versions have only been developed to work

15. The third floor. A view looking south of a ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. The third floor. A view looking south of a typical corridor for these two upper floors. All windows have a single obscure glass light and shoulder high sills which bring sunlight into the corridor. The a/c duct, its laterals and the fluorescent light elements are all retrofit. - John T. Beasley Building, 632 Cherry Street (between Sixth & Seventh Streets), Terre Haute, Vigo County, IN

Improved Distance Learning Environment For Marine Forces Reserve

DTIC Science & Technology

2016-09-01

keyboard, to 20 form a desktop computer . Laptop computers share similar components but add mobility to the user. If additional desktop computers ...for stationary computing devices such as desktop PCs and laptops include the Microsoft Windows, Mac OS, and Linux families of OSs 44 (Hopkins...opportunities to all Marines. For active duty Marines, government-provided desktops and laptops (GPDLs) typically support DL T&E or learning resource

Ultrasound-guided identification of cardiac imaging windows.

PubMed

Liu, Garry; Qi, Xiu-Ling; Robert, Normand; Dick, Alexander J; Wright, Graham A

2012-06-01

Currently, the use of cine magnetic resonance imaging (MRI) to identify cardiac quiescent periods relative to the electrocardiogram (ECG) signal is insufficient for producing submillimeter-resolution coronary MR angiography (MRA) images. In this work, the authors perform a time series comparison between tissue Doppler echocardiograms of the interventricular septum (IVS) and concurrent biplane x-ray angiograms. Our results indicate very close agreement between the diastasis gating windows identified by both the IVS and x-ray techniques. Seven cath lab patients undergoing diagnostic angiograms were simultaneously scanned during a breath hold by ultrasound and biplane x-ray for six to eight heartbeats. The heart rate of each patient was stable. Dye was injected into either the left or right-coronary vasculature. The IVS was imaged using color tissue Doppler in an apical four-chamber view. Diastasis was estimated on the IVS velocity curve. On the biplane angiograms, proximal, mid, and distal regions were identified on the coronary artery (CA). Frame by frame correlation was used to derive displacement, and then velocity, for each region. The quiescent periods for a CA and its subsegments were estimated based on velocity. Using Pearson's correlation coefficient and Bland-Altman analysis, the authors compared the start and end times of the diastasis windows as estimated from the IVS and CA velocities. The authors also estimated the vessel blur across the diastasis windows of multiple sequential heartbeats of each patient. In total, 17 heartbeats were analyzed. The range of heart rate observed across patients was 47-79 beats per minute (bpm) with a mean of 57 bpm. Significant correlations (R > 0.99; p < 0.01) were observed between the IVS and x-ray techniques for the identification of the start and end times of diastasis windows. The mean difference in the starting times between IVS and CA quiescent windows was -12.0 ms. The mean difference in end times between IVS and CA quiescent windows was -3.5 ms. In contrast, the correlation between RR interval and both the start and duration of the x-ray gating windows were relatively weaker: R = 0.63 (p = 0.13) and R = 0.86 (p = 0.01). For IVS gating windows, the average estimated vessel blurs during single and multiple heartbeats were 0.5 and 0.66 mm, respectively. For x-ray gating windows, the corresponding values were 0.26 and 0.44 mm, respectively. In this study, the authors showed that IVS velocity can be used to identify periods of diastasis for coronary arteries. Despite variability in mid-diastolic rest positions over multiple steady rate heartbeats, vessel blurring of 0.5-1 mm was found to be achievable using the IVS gating technique. The authors envision this leading to a new cardiac gating system that, compared with conventional ECG gating, provides better resolution and shorter scan times for coronary MRA. © 2012 American Association of Physicists in Medicine.

Image-guided adaptive gating of lung cancer radiotherapy: a computer simulation study

NASA Astrophysics Data System (ADS)

Aristophanous, Michalis; Rottmann, Joerg; Park, Sang-June; Nishioka, Seiko; Shirato, Hiroki; Berbeco, Ross I.

2010-08-01

The purpose of this study is to investigate the effect that image-guided adaptation of the gating window during treatment could have on the residual tumor motion, by simulating different gated radiotherapy techniques. There are three separate components of this simulation: (1) the 'Hokkaido Data', which are previously measured 3D data of lung tumor motion tracks and the corresponding 1D respiratory signals obtained during the entire ungated radiotherapy treatments of eight patients, (2) the respiratory gating protocol at our institution and the imaging performed under that protocol and (3) the actual simulation in which the Hokkaido Data are used to select tumor position information that could have been collected based on the imaging performed under our gating protocol. We simulated treatments with a fixed gating window and a gating window that is updated during treatment. The patient data were divided into different fractions, each with continuous acquisitions longer than 2 min. In accordance to the imaging performed under our gating protocol, we assume that we have tumor position information for the first 15 s of treatment, obtained from kV fluoroscopy, and for the rest of the fractions the tumor position is only available during the beam-on time from MV imaging. The gating window was set according to the information obtained from the first 15 s such that the residual motion was less than 3 mm. For the fixed gating window technique the gate remained the same for the entire treatment, while for the adaptive technique the range of the tumor motion during beam-on time was measured and used to adapt the gating window to keep the residual motion below 3 mm. The algorithm used to adapt the gating window is described. The residual tumor motion inside the gating window was reduced on average by 24% for the patients with regular breathing patterns and the difference was statistically significant (p-value = 0.01). The magnitude of the residual tumor motion depended on the regularity of the breathing pattern suggesting that image-guided adaptive gating should be combined with breath coaching. The adaptive gating window technique was able to track the exhale position of the breathing cycle quite successfully. Out of a total of 53 fractions the duty cycle was greater than 20% for 42 fractions for the fixed gating window technique and for 39 fractions for the adaptive gating window technique. The results of this study suggest that real-time updating of the gating window can result in reliably low residual tumor motion and therefore can facilitate safe margin reduction.

Multi-Window Controllers for Autonomous Space Systems

NASA Technical Reports Server (NTRS)

Lurie, B, J.; Hadaegh, F. Y.

1997-01-01

Multi-window controllers select between elementary linear controllers using nonlinear windows based on the amplitude and frequency content of the feedback error. The controllers are relatively simple to implement and perform much better than linear controllers. The commanders for such controllers only order the destination point and are freed from generating the command time-profiles. The robotic missions rely heavily on the tasks of acquisition and tracking. For autonomous and optimal control of the spacecraft, the control bandwidth must be larger while the feedback can (and, therefore, must) be reduced.. Combining linear compensators via multi-window nonlinear summer guarantees minimum phase character of the combined transfer function. It is shown that the solution may require using several parallel branches and windows. Several examples of multi-window nonlinear controller applications are presented.

IR window design for hypersonic missile seekers: thermal shock and cooling systems

NASA Astrophysics Data System (ADS)

Hingst, Uwe; Koerber, Stefan

2001-10-01

Infra-red (IR) seekers on missiles at high Mach-numbers in the lower tier air defence often suffer from degradation in performance due to aerothermodynamic effects. The kind and rate of degradation depends on the geometric design (shape) and location of the IR-window. Optimal design may reduce those effects but still misses to totally withstand the imposed thermal stresses (thermal shock). Proper thermal protection systems and/or window cooling systems will be needed. The first part of this paper deals particularly with passive IR- window design features to reduce the thermal stresses. A series of wind-tunnel testings focused on the thermal shock behavior of different IR-window shapes under critical flight conditions. The variation of typical design parameters demonstrates the available features to reduce thermal shock by passive ways. The second part presents active thermal stress reduction devices, e.g. an active cooling system. Among others the most efficient reduction of thermal heating is based on three components: A partial coverage of the IR-dome to protect most parts against heating effects, a rotating system bearing the IR-dome and a liquid spray-cooling system in the gap between the cover and the IR-dome. The hemispherical or pyramidal dome can be located either midways in the missile nose section or sideways on the structure. The liquid spray cooling system combines both, a heat exchange by fluid evaporation and a heat transfer by fluid and gas cross flow (convection), causing a low fluid consumption. Such a cooling system along with their driving parameters and the resulting analytical performance will be presented.

Rapid determination of particle velocity from space-time images using the Radon transform

PubMed Central

Drew, Patrick J.; Blinder, Pablo; Cauwenberghs, Gert; Shih, Andy Y.; Kleinfeld, David

2016-01-01

Laser-scanning methods are a means to observe streaming particles, such as the flow of red blood cells in a blood vessel. Typically, particle velocity is extracted from images formed from cyclically repeated line-scan data that is obtained along the center-line of the vessel; motion leads to streaks whose angle is a function of the velocity. Past methods made use of shearing or rotation of the images and a Singular Value Decomposition (SVD) to automatically estimate the average velocity in a temporal window of data. Here we present an alternative method that makes use of the Radon transform to calculate the velocity of streaming particles. We show that this method is over an order of magnitude faster than the SVD-based algorithm and is more robust to noise. PMID:19459038

All-optical switching in GaAs microdisk resonators by a femtosecond pump-probe technique through tapered-fiber coupling.

PubMed

Lin, Yen-Chih; Mao, Ming-Hua; Lin, You-Ru; Lin, Hao-Hsiung; Lin, Che-An; Wang, Lon A

2014-09-01

We demonstrate ultrafast all-optical switching in GaAs microdisk resonators using a femtosecond pump-probe technique through tapered-fiber coupling. The temporal tuning of the resonant modes resulted from the refractive index change due to photoexcited carrier density variation inside the GaAs microdisk resonator. Transmission through the GaAs microdisk resonator can be modulated by more than 10 dB with a switching time window of 8 ps in the switch-off operation using pumping pulses with energies as low as 17.5 pJ. The carrier lifetime was fitted to be 42 ps, much shorter than that of the bulk GaAs, typically of the order of nanoseconds. The above observation indicates that the surface recombination plays an important role in increasing the switching speed.

High-flux soft x-ray harmonic generation from ionization-shaped few-cycle laser pulses

PubMed Central

Brahms, Christian; Gregory, Andrew; Tisch, John W. G.; Marangos, Jon P.

2018-01-01

Laser-driven high-harmonic generation provides the only demonstrated route to generating stable, tabletop attosecond x-ray pulses but has low flux compared to other x-ray technologies. We show that high-harmonic generation can produce higher photon energies and flux by using higher laser intensities than are typical, strongly ionizing the medium and creating plasma that reshapes the driving laser field. We obtain high harmonics capable of supporting attosecond pulses up to photon energies of 600 eV and a photon flux inside the water window (284 to 540 eV) 10 times higher than previous attosecond sources. We demonstrate that operating in this regime is key for attosecond pulse generation in the x-ray range and will become increasingly important as harmonic generation moves to fields that drive even longer wavelengths. PMID:29756033

Comparing on-road real-time simultaneous in-cabin and outdoor particulate and gaseous concentrations for a range of ventilation scenarios

NASA Astrophysics Data System (ADS)

Leavey, Anna; Reed, Nathan; Patel, Sameer; Bradley, Kevin; Kulkarni, Pramod; Biswas, Pratim

2017-10-01

Advanced automobile technology, developed infrastructure, and changing economic markets have resulted in increasing commute times. Traffic is a major source of harmful pollutants and consequently daily peak exposures tend to occur near roadways or while travelling on them. The objective of this study was to measure simultaneous real-time particulate matter (particle numbers, lung-deposited surface area, PM2.5, particle number size distributions) and CO concentrations outside and in-cabin of an on-road car during regular commutes to and from work. Data was collected for different ventilation parameters (windows open or closed, fan on, AC on), whilst travelling along different road-types with varying traffic densities. Multiple predictor variables were examined using linear mixed-effects models. Ambient pollutants (NOx, PM2.5, CO) and meteorological variables (wind speed, temperature, relative humidity, dew point) explained 5-44% of outdoor pollutant variability, while the time spent travelling behind a bus was statistically significant for PM2.5, lung-deposited SA, and CO (adj-R2 values = 0.12, 0.10, 0.13). The geometric mean diameter (GMD) for outdoor aerosol was 34 nm. Larger cabin GMDs were observed when windows were closed compared to open (b = 4.3, p-value = <0.01). When windows were open, cabin total aerosol concentrations tracked those outdoors. With windows closed, the pollutants took longer to enter the vehicle cabin, but also longer to exit it. Concentrations of pollutants in cabin were influenced by outdoor concentrations, ambient temperature, and the window/ventilation parameters. As expected, particle number concentrations were impacted the most by changes to window position/ventilation, and PM2.5 the least. Car drivers can expect their highest exposures when driving with windows open or the fan on, and their lowest exposures during windows closed or the AC on. Final linear mixed-effects models could explain between 88 and 97% of cabin pollutant concentration variability. An individual may control their commuting exposure by applying dynamic behavior modification to adapt to changing pollutant scenarios.

Comparing on-road real-time simultaneous in-cabin and outdoor particulate and gaseous concentrations for a range of ventilation scenarios

PubMed Central

Leavey, Anna; Reed, Nathan; Patel, Sameer; Bradley, Kevin; Kulkarni, Pramod; Biswas, Pratim

2017-01-01

Advanced automobile technology, developed infrastructure, and changing economic markets have resulted in increasing commute times. Traffic is a major source of harmful pollutants and consequently daily peak exposures tend to occur near roadways or while traveling on them. The objective of this study was to measure simultaneous real-time particulate matter (particle numbers, lung-deposited surface area, PM2.5, particle number size distributions) and CO concentrations outside and in-cabin of an on-road car during regular commutes to and from work. Data was collected for different ventilation parameters (windows open or closed, fan on, AC on), whilst traveling along different road-types with varying traffic densities. Multiple predictor variables were examined using linear mixed-effects models. Ambient pollutants (NOx, PM2.5, CO) and meteorological variables (wind speed, temperature, relative humidity, dew point) explained 5–44% of outdoor pollutant variability, while the time spent travelling behind a bus was statistically significant for PM2.5, lung-deposited SA, and CO (adj-R2 values = 0.12, 0.10, 0.13). The geometric mean diameter (GMD) for outdoor aerosol was 34 nm. Larger cabin GMDs were observed when windows were closed compared to open (b = 4.3, p-value = <0.01). When windows were open, cabin total aerosol concentrations tracked those outdoors. With windows closed, the pollutants took longer to enter the vehicle cabin, but also longer to exit it. Concentrations of pollutants in cabin were influenced by outdoor concentrations, ambient temperature, and the window/ventilation parameters. As expected, particle number concentrations were impacted the most by changes to window position / ventilation, and PM2.5 the least. Car drivers can expect their highest exposures when driving with windows open or the fan on, and their lowest exposures during windows closed or the AC on. Final linear mixed-effects models could explain between 88–97% of cabin pollutant concentration variability. An individual may control their commuting exposure by applying dynamic behavior modification to adapt to changing pollutant scenarios. PMID:29284988

Comparing on-road real-time simultaneous in-cabin and outdoor particulate and gaseous concentrations for a range of ventilation scenarios.

PubMed

Leavey, Anna; Reed, Nathan; Patel, Sameer; Bradley, Kevin; Kulkarni, Pramod; Biswas, Pratim

2017-10-01

Advanced automobile technology, developed infrastructure, and changing economic markets have resulted in increasing commute times. Traffic is a major source of harmful pollutants and consequently daily peak exposures tend to occur near roadways or while traveling on them. The objective of this study was to measure simultaneous real-time particulate matter (particle numbers, lung-deposited surface area, PM 2.5 , particle number size distributions) and CO concentrations outside and in-cabin of an on-road car during regular commutes to and from work. Data was collected for different ventilation parameters (windows open or closed, fan on, AC on), whilst traveling along different road-types with varying traffic densities. Multiple predictor variables were examined using linear mixed-effects models. Ambient pollutants (NO x , PM 2.5 , CO) and meteorological variables (wind speed, temperature, relative humidity, dew point) explained 5-44% of outdoor pollutant variability, while the time spent travelling behind a bus was statistically significant for PM 2.5, lung-deposited SA, and CO (adj-R 2 values = 0.12, 0.10, 0.13). The geometric mean diameter (GMD) for outdoor aerosol was 34 nm. Larger cabin GMDs were observed when windows were closed compared to open (b = 4.3, p-value = <0.01). When windows were open, cabin total aerosol concentrations tracked those outdoors. With windows closed, the pollutants took longer to enter the vehicle cabin, but also longer to exit it. Concentrations of pollutants in cabin were influenced by outdoor concentrations, ambient temperature, and the window/ventilation parameters. As expected, particle number concentrations were impacted the most by changes to window position / ventilation, and PM 2.5 the least. Car drivers can expect their highest exposures when driving with windows open or the fan on, and their lowest exposures during windows closed or the AC on. Final linear mixed-effects models could explain between 88-97% of cabin pollutant concentration variability. An individual may control their commuting exposure by applying dynamic behavior modification to adapt to changing pollutant scenarios.

Prognostic models based on patient snapshots and time windows: Predicting disease progression to assisted ventilation in Amyotrophic Lateral Sclerosis.

PubMed

Carreiro, André V; Amaral, Pedro M T; Pinto, Susana; Tomás, Pedro; de Carvalho, Mamede; Madeira, Sara C

2015-12-01

Amyotrophic Lateral Sclerosis (ALS) is a devastating disease and the most common neurodegenerative disorder of young adults. ALS patients present a rapidly progressive motor weakness. This usually leads to death in a few years by respiratory failure. The correct prediction of respiratory insufficiency is thus key for patient management. In this context, we propose an innovative approach for prognostic prediction based on patient snapshots and time windows. We first cluster temporally-related tests to obtain snapshots of the patient's condition at a given time (patient snapshots). Then we use the snapshots to predict the probability of an ALS patient to require assisted ventilation after k days from the time of clinical evaluation (time window). This probability is based on the patient's current condition, evaluated using clinical features, including functional impairment assessments and a complete set of respiratory tests. The prognostic models include three temporal windows allowing to perform short, medium and long term prognosis regarding progression to assisted ventilation. Experimental results show an area under the receiver operating characteristics curve (AUC) in the test set of approximately 79% for time windows of 90, 180 and 365 days. Creating patient snapshots using hierarchical clustering with constraints outperforms the state of the art, and the proposed prognostic model becomes the first non population-based approach for prognostic prediction in ALS. The results are promising and should enhance the current clinical practice, largely supported by non-standardized tests and clinicians' experience. Copyright © 2015 Elsevier Inc. All rights reserved.

Ultrafast fluorescence imaging in vivo with conjugated polymer fluorophores in the second near-infrared window

NASA Astrophysics Data System (ADS)

Hong, Guosong; Zou, Yingping; Antaris, Alexander L.; Diao, Shuo; Wu, Di; Cheng, Kai; Zhang, Xiaodong; Chen, Changxin; Liu, Bo; He, Yuehui; Wu, Justin Z.; Yuan, Jun; Zhang, Bo; Tao, Zhimin; Fukunaga, Chihiro; Dai, Hongjie

2014-06-01

In vivo fluorescence imaging in the second near-infrared window (1.0-1.7 μm) can afford deep tissue penetration and high spatial resolution, owing to the reduced scattering of long-wavelength photons. Here we synthesize a series of low-bandgap donor/acceptor copolymers with tunable emission wavelengths of 1,050-1,350 nm in this window. Non-covalent functionalization with phospholipid-polyethylene glycol results in water-soluble and biocompatible polymeric nanoparticles, allowing for live cell molecular imaging at >1,000 nm with polymer fluorophores for the first time. Importantly, the high quantum yield of the polymer allows for in vivo, deep-tissue and ultrafast imaging of mouse arterial blood flow with an unprecedented frame rate of >25 frames per second. The high time-resolution results in spatially and time resolved imaging of the blood flow pattern in cardiogram waveform over a single cardiac cycle (~200 ms) of a mouse, which has not been observed with fluorescence imaging in this window before.

Low-complexity image processing for real-time detection of neonatal clonic seizures.

PubMed

Ntonfo, Guy Mathurin Kouamou; Ferrari, Gianluigi; Raheli, Riccardo; Pisani, Francesco

2012-05-01

In this paper, we consider a novel low-complexity real-time image-processing-based approach to the detection of neonatal clonic seizures. Our approach is based on the extraction, from a video of a newborn, of an average luminance signal representative of the body movements. Since clonic seizures are characterized by periodic movements of parts of the body (e.g., the limbs), by evaluating the periodicity of the extracted average luminance signal it is possible to detect the presence of a clonic seizure. The periodicity is investigated, through a hybrid autocorrelation-Yin estimation technique, on a per-window basis, where a time window is defined as a sequence of consecutive video frames. While processing is first carried out on a single window basis, we extend our approach to interlaced windows. The performance of the proposed detection algorithm is investigated, in terms of sensitivity and specificity, through receiver operating characteristic curves, considering video recordings of newborns affected by neonatal seizures.

Smart glass as the method of improving the energy efficiency of high-rise buildings

NASA Astrophysics Data System (ADS)

Gamayunova, Olga; Gumerova, Eliza; Miloradova, Nadezda

2018-03-01

The question that has to be answered in high-rise building is glazing and its service life conditions. Contemporary market offers several types of window units, for instance, wooden, aluminum, PVC and combined models. Wooden and PVC windows become the most widespread and competitive between each other. In recent times design engineers choose smart glass. In this article, the advantages and drawbacks of all types of windows are reviewed, and the recommendations are given according to choice of window type in order to improve energy efficiency of buildings.

Limits to high-speed simulations of spiking neural networks using general-purpose computers.

PubMed

Zenke, Friedemann; Gerstner, Wulfram

2014-01-01

To understand how the central nervous system performs computations using recurrent neuronal circuitry, simulations have become an indispensable tool for theoretical neuroscience. To study neuronal circuits and their ability to self-organize, increasing attention has been directed toward synaptic plasticity. In particular spike-timing-dependent plasticity (STDP) creates specific demands for simulations of spiking neural networks. On the one hand a high temporal resolution is required to capture the millisecond timescale of typical STDP windows. On the other hand network simulations have to evolve over hours up to days, to capture the timescale of long-term plasticity. To do this efficiently, fast simulation speed is the crucial ingredient rather than large neuron numbers. Using different medium-sized network models consisting of several thousands of neurons and off-the-shelf hardware, we compare the simulation speed of the simulators: Brian, NEST and Neuron as well as our own simulator Auryn. Our results show that real-time simulations of different plastic network models are possible in parallel simulations in which numerical precision is not a primary concern. Even so, the speed-up margin of parallelism is limited and boosting simulation speeds beyond one tenth of real-time is difficult. By profiling simulation code we show that the run times of typical plastic network simulations encounter a hard boundary. This limit is partly due to latencies in the inter-process communications and thus cannot be overcome by increased parallelism. Overall, these results show that to study plasticity in medium-sized spiking neural networks, adequate simulation tools are readily available which run efficiently on small clusters. However, to run simulations substantially faster than real-time, special hardware is a prerequisite.

Determining the optimal window length for pattern recognition-based myoelectric control: balancing the competing effects of classification error and controller delay.

PubMed

Smith, Lauren H; Hargrove, Levi J; Lock, Blair A; Kuiken, Todd A

2011-04-01

Pattern recognition-based control of myoelectric prostheses has shown great promise in research environments, but has not been optimized for use in a clinical setting. To explore the relationship between classification error, controller delay, and real-time controllability, 13 able-bodied subjects were trained to operate a virtual upper-limb prosthesis using pattern recognition of electromyogram (EMG) signals. Classification error and controller delay were varied by training different classifiers with a variety of analysis window lengths ranging from 50 to 550 ms and either two or four EMG input channels. Offline analysis showed that classification error decreased with longer window lengths (p < 0.01 ). Real-time controllability was evaluated with the target achievement control (TAC) test, which prompted users to maneuver the virtual prosthesis into various target postures. The results indicated that user performance improved with lower classification error (p < 0.01 ) and was reduced with longer controller delay (p < 0.01 ), as determined by the window length. Therefore, both of these effects should be considered when choosing a window length; it may be beneficial to increase the window length if this results in a reduced classification error, despite the corresponding increase in controller delay. For the system employed in this study, the optimal window length was found to be between 150 and 250 ms, which is within acceptable controller delays for conventional multistate amplitude controllers.

Absorption characterization of immersion medium for multiphoton microscopy at the 1700nm window

NASA Astrophysics Data System (ADS)

Wen, Wenhui; Qiu, Ping

2017-02-01

Larger imaging depth is the quest of almost all the imaging modalities, including multiphoton microscopy (MPM). Recently, it has been domonstrated that excitation at the 1700-nm helps extending imaging depth in MPM, optical coherence tomography, as well as photoacoustic imaging compared with excitation at other wavelengths. In MPM, immersion objective lenses with high numerical aperture (NA) are typically used to achieve better signal resolution, higer signal collection efficiency, and stronger signal generation. Although physically short ( mm), this extra optical path length traversed by the excitation light inevitably introduces absorption of the excitation light, and as a result leads to a decrease in the signal generation. Here we demonstrate experimental characterization of absorption spectrum of various immersion media at the 1700-nm window, including water (H2O), deuterium oxide (D2O), and several brands of immersion oil. Our results identify either the best immersion medium for a specific wavelength, or the best wavelength for a specific immersion medium at the 1700-nm window. Furthermore, through quantitative MPM experiments comparing different immersion media, we show that the MPM signal levels can be enhanced by more than ten fold simply by selecting the proper immersion medium, in good agreement with theoretical expectation based on the absorption measurement. Our results will offer guidelines for signal optimization in MPM at the 1700-nm window.

Statistical tests for power-law cross-correlated processes

NASA Astrophysics Data System (ADS)

Podobnik, Boris; Jiang, Zhi-Qiang; Zhou, Wei-Xing; Stanley, H. Eugene

2011-12-01

For stationary time series, the cross-covariance and the cross-correlation as functions of time lag n serve to quantify the similarity of two time series. The latter measure is also used to assess whether the cross-correlations are statistically significant. For nonstationary time series, the analogous measures are detrended cross-correlations analysis (DCCA) and the recently proposed detrended cross-correlation coefficient, ρDCCA(T,n), where T is the total length of the time series and n the window size. For ρDCCA(T,n), we numerically calculated the Cauchy inequality -1≤ρDCCA(T,n)≤1. Here we derive -1≤ρDCCA(T,n)≤1 for a standard variance-covariance approach and for a detrending approach. For overlapping windows, we find the range of ρDCCA within which the cross-correlations become statistically significant. For overlapping windows we numerically determine—and for nonoverlapping windows we derive—that the standard deviation of ρDCCA(T,n) tends with increasing T to 1/T. Using ρDCCA(T,n) we show that the Chinese financial market's tendency to follow the U.S. market is extremely weak. We also propose an additional statistical test that can be used to quantify the existence of cross-correlations between two power-law correlated time series.

Windowed time-reversal music technique for super-resolution ultrasound imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Lianjie; Labyed, Yassin

Systems and methods for super-resolution ultrasound imaging using a windowed and generalized TR-MUSIC algorithm that divides the imaging region into overlapping sub-regions and applies the TR-MUSIC algorithm to the windowed backscattered ultrasound signals corresponding to each sub-region. The algorithm is also structured to account for the ultrasound attenuation in the medium and the finite-size effects of ultrasound transducer elements.

The Golden Cage: Growing up in the Socialist Yugoslavia

ERIC Educational Resources Information Center

Marjanovic-Shane, Ana

2018-01-01

From the mid 1950s through roughly the 1980s, some or many children and youth of the Socialist Yugoslavia, especially those of us in Belgrade, the capital, lived in a curious, almost surreal "window" in the space and time. This surreal window of space-time, offered to children and youth of Yugoslavia, unprecedented opportunities for…

Alternative Fuels Data Center: Maine's Only Biodiesel Manufacturer Powers

Science.gov Websites

this project, contact Maine Clean Communities. Download QuickTime Video QuickTime (.mov) Download Windows Media Video Windows Media (.wmv) Video Download Help Text version See more videos provided by truck Krug Energy Opens Natural Gas Fueling Station in Arkansas June 18, 2016 photo of natural gas

Alternative Fuels Data Center: Texas Taxis Go Hybrid

Science.gov Websites

information about this project, contact Alamo Area Clean Cities (San Antonio). Download QuickTime Video QuickTime (.mov) Download Windows Media Video Windows Media (.wmv) Video Download Help Text version See more car Hydrogen Powers Fuel Cell Vehicles in California Nov. 18, 2017 Photo of a car Smart Car Shopping

Iconic Meaning in Music: An Event-Related Potential Study.

PubMed

Cai, Liman; Huang, Ping; Luo, Qiuling; Huang, Hong; Mo, Lei

2015-01-01

Although there has been extensive research on the processing of the emotional meaning of music, little is known about other aspects of listeners' experience of music. The present study investigated the neural correlates of the iconic meaning of music. Event-related potentials (ERP) were recorded while a group of 20 music majors and a group of 20 non-music majors performed a lexical decision task in the context of implicit musical iconic meaning priming. ERP analysis revealed a significant N400 effect of congruency in time window 260-510 ms following the onset of the target word only in the group of music majors. Time-course analysis using 50 ms windows indicated significant N400 effects both within the time window 410-460 ms and 460-510 ms for music majors, whereas only a partial N400 effect during time window 410-460 ms was observed for non-music majors. There was also a trend for the N400 effects in the music major group to be stronger than those in the non-major group in the sub-windows of 310-360 ms and 410-460 ms. Especially in the sub-window of 410-460 ms, the topographical map of the difference waveforms between congruent and incongruent conditions revealed different N400 distribution between groups; the effect was concentrated in bilateral frontal areas for music majors, but in central-parietal areas for non-music majors. These results imply probable neural mechanism differences underlying automatic iconic meaning priming of music. Our findings suggest that processing of the iconic meaning of music can be accomplished automatically and that musical training may facilitate the understanding of the iconic meaning of music.

Iconic Meaning in Music: An Event-Related Potential Study

PubMed Central

Luo, Qiuling; Huang, Hong; Mo, Lei

2015-01-01

Although there has been extensive research on the processing of the emotional meaning of music, little is known about other aspects of listeners’ experience of music. The present study investigated the neural correlates of the iconic meaning of music. Event-related potentials (ERP) were recorded while a group of 20 music majors and a group of 20 non-music majors performed a lexical decision task in the context of implicit musical iconic meaning priming. ERP analysis revealed a significant N400 effect of congruency in time window 260-510 ms following the onset of the target word only in the group of music majors. Time-course analysis using 50 ms windows indicated significant N400 effects both within the time window 410-460 ms and 460-510 ms for music majors, whereas only a partial N400 effect during time window 410-460 ms was observed for non-music majors. There was also a trend for the N400 effects in the music major group to be stronger than those in the non-major group in the sub-windows of 310-360ms and 410-460ms. Especially in the sub-window of 410-460 ms, the topographical map of the difference waveforms between congruent and incongruent conditions revealed different N400 distribution between groups; the effect was concentrated in bilateral frontal areas for music majors, but in central-parietal areas for non-music majors. These results imply probable neural mechanism differences underlying automatic iconic meaning priming of music. Our findings suggest that processing of the iconic meaning of music can be accomplished automatically and that musical training may facilitate the understanding of the iconic meaning of music. PMID:26161561

Issues in visual support to real-time space system simulation solved in the Systems Engineering Simulator

NASA Technical Reports Server (NTRS)

Yuen, Vincent K.

1989-01-01

The Systems Engineering Simulator has addressed the major issues in providing visual data to its real-time man-in-the-loop simulations. Out-the-window views and CCTV views are provided by three scene systems to give the astronauts their real-world views. To expand the window coverage for the Space Station Freedom workstation a rotating optics system is used to provide the widest field of view possible. To provide video signals to as many viewpoints as possible, windows and CCTVs, with a limited amount of hardware, a video distribution system has been developed to time-share the video channels among viewpoints at the selection of the simulation users. These solutions have provided the visual simulation facility for real-time man-in-the-loop simulations for the NASA space program.

Split delivery vehicle routing problem with time windows: a case study

NASA Astrophysics Data System (ADS)

Latiffianti, E.; Siswanto, N.; Firmandani, R. A.

2018-04-01

This paper aims to implement an extension of VRP so called split delivery vehicle routing problem (SDVRP) with time windows in a case study involving pickups and deliveries of workers from several points of origin and several destinations. Each origin represents a bus stop and the destination represents either site or office location. An integer linear programming of the SDVRP problem is presented. The solution was generated using three stages of defining the starting points, assigning busses, and solving the SDVRP with time windows using an exact method. Although the overall computational time was relatively lengthy, the results indicated that the produced solution was better than the existing routing and scheduling that the firm used. The produced solution was also capable of reducing fuel cost by 9% that was obtained from shorter total distance travelled by the shuttle buses.

The Use of Variable Q1 Isolation Windows Improves Selectivity in LC-SWATH-MS Acquisition.

PubMed

Zhang, Ying; Bilbao, Aivett; Bruderer, Tobias; Luban, Jeremy; Strambio-De-Castillia, Caterina; Lisacek, Frédérique; Hopfgartner, Gérard; Varesio, Emmanuel

2015-10-02

As tryptic peptides and metabolites are not equally distributed along the mass range, the probability of cross fragment ion interference is higher in certain windows when fixed Q1 SWATH windows are applied. We evaluated the benefits of utilizing variable Q1 SWATH windows with regards to selectivity improvement. Variable windows based on equalizing the distribution of either the precursor ion population (PIP) or the total ion current (TIC) within each window were generated by an in-house software, swathTUNER. These two variable Q1 SWATH window strategies outperformed, with respect to quantification and identification, the basic approach using a fixed window width (FIX) for proteomic profiling of human monocyte-derived dendritic cells (MDDCs). Thus, 13.8 and 8.4% additional peptide precursors, which resulted in 13.1 and 10.0% more proteins, were confidently identified by SWATH using the strategy PIP and TIC, respectively, in the MDDC proteomic sample. On the basis of the spectral library purity score, some improvement warranted by variable Q1 windows was also observed, albeit to a lesser extent, in the metabolomic profiling of human urine. We show that the novel concept of "scheduled SWATH" proposed here, which incorporates (i) variable isolation windows and (ii) precursor retention time segmentation further improves both peptide and metabolite identifications.

A true minimally invasive approach for cochlear implantation: high accuracy in cranial base navigation through flat-panel-based volume computed tomography.

PubMed

Majdani, Omid; Bartling, Soenke H; Leinung, Martin; Stöver, Timo; Lenarz, Minoo; Dullin, Christian; Lenarz, Thomas

2008-02-01

High-precision intraoperative navigation using high-resolution flat-panel volume computed tomography makes feasible the possibility of minimally invasive cochlear implant surgery, including cochleostomy. Conventional cochlear implant surgery is typically performed via mastoidectomy with facial recess to identify and avoid damage to vital anatomic landmarks. To accomplish this procedure via a minimally invasive approach--without performing mastoidectomy--in a precise fashion, image-guided technology is necessary. With such an approach, surgical time and expertise may be reduced, and hearing preservation may be improved. Flat-panel volume computed tomography was used to scan 4 human temporal bones. A drilling channel was planned preoperatively from the mastoid surface to the round window niche, providing a margin of safety to all functional important structures (e.g., facial nerve, chorda tympani, incus). Postoperatively, computed tomographic imaging and conventional surgical exploration of the drilled route to the cochlea were performed. All 4 specimens showed a cochleostomy located at the scala tympani anterior inferior to the round window. The chorda tympani was damaged in 1 specimen--this was preoperatively planned as a narrow facial recess was encountered. Using flat-panel volume computed tomography for image-guided surgical navigation, we were able to perform minimally invasive cochlear implant surgery defined as a narrow, single-channel mastoidotomy with cochleostomy. Although this finding is preliminary, it is technologically achievable.

In Situ Visualization of the Phase Behavior of Oil Samples Under Refinery Process Conditions.

PubMed

Laborde-Boutet, Cedric; McCaffrey, William C

2017-02-21

To help address production issues in refineries caused by the fouling of process units and lines, we have developed a setup as well as a method to visualize the behavior of petroleum samples under process conditions. The experimental setup relies on a custom-built micro-reactor fitted with a sapphire window at the bottom, which is placed over the objective of an inverted microscope equipped with a cross-polarizer module. Using reflection microscopy enables the visualization of opaque samples, such as petroleum vacuum residues, or asphaltenes. The combination of the sapphire window from the micro-reactor with the cross-polarizer module of the microscope on the light path allows high-contrast imaging of isotropic and anisotropic media. While observations are carried out, the micro-reactor can be heated to the temperature range of cracking reactions (up to 450 °C), can be subjected to H2 pressure relevant to hydroconversion reactions (up to 16 MPa), and can stir the sample by magnetic coupling. Observations are typically carried out by taking snapshots of the sample under cross-polarized light at regular time intervals. Image analyses may not only provide information on the temperature, pressure, and reactive conditions yielding phase separation, but may also give an estimate of the evolution of the chemical (absorption/reflection spectra) and physical (refractive index) properties of the sample before the onset of phase separation.

Early Warning for Large Magnitude Earthquakes: Is it feasible?

NASA Astrophysics Data System (ADS)

Zollo, A.; Colombelli, S.; Kanamori, H.

2011-12-01

The mega-thrust, Mw 9.0, 2011 Tohoku earthquake has re-opened the discussion among the scientific community about the effectiveness of Earthquake Early Warning (EEW) systems, when applied to such large events. Many EEW systems are now under-testing or -development worldwide and most of them are based on the real-time measurement of ground motion parameters in a few second window after the P-wave arrival. Currently, we are using the initial Peak Displacement (Pd), and the Predominant Period (τc), among other parameters, to rapidly estimate the earthquake magnitude and damage potential. A well known problem about the real-time estimation of the magnitude is the parameter saturation. Several authors have shown that the scaling laws between early warning parameters and magnitude are robust and effective up to magnitude 6.5-7; the correlation, however, has not yet been verified for larger events. The Tohoku earthquake occurred near the East coast of Honshu, Japan, on the subduction boundary between the Pacific and the Okhotsk plates. The high quality Kik- and K- networks provided a large quantity of strong motion records of the mainshock, with a wide azimuthal coverage both along the Japan coast and inland. More than 300 3-component accelerograms have been available, with an epicentral distance ranging from about 100 km up to more than 500 km. This earthquake thus presents an optimal case study for testing the physical bases of early warning and to investigate the feasibility of a real-time estimation of earthquake size and damage potential even for M > 7 earthquakes. In the present work we used the acceleration waveform data of the main shock for stations along the coast, up to 200 km epicentral distance. We measured the early warning parameters, Pd and τc, within different time windows, starting from 3 seconds, and expanding the testing time window up to 30 seconds. The aim is to verify the correlation of these parameters with Peak Ground Velocity and Magnitude, respectively, as a function of the length of the P-wave window. The entire rupture process of the Tohoku earthquake lasted more than 120 seconds, as shown by the source time functions obtained by several authors. When a 3 second window is used to measure Pd and τc the result is an obvious underestimation of the event size and final PGV. However, as the time window increases up to 27-30 seconds, the measured values of Pd and τc become comparable with those expected for a magnitude M≥8.5 earthquake, according to the τc vs. M and the PGV vs. Pd relationships obtained in a previous work. Since we did not observe any saturation effect for the predominant period and peak displacement measured within a P-wave, 30-seconds window, we infer that, at least from a theoretical point of view, the estimation of earthquake damage potential through the early warning parameters is still feasible for large events, provided that a longer time window is used for parameter measurement. The off-line analysis of the Tohoku event records shows that reliable estimations of the damage potential could have been obtained 40-50 seconds after the origin time, by updating the measurements of the early warning parameters in progressively enlarged P-wave time windows from 3 to 30 seconds.

Abdicating power for control: a precision timing strategy to modulate function of flight power muscles.

PubMed

Sponberg, S; Daniel, T L

2012-10-07

Muscles driving rhythmic locomotion typically show strong dependence of power on the timing or phase of activation. This is particularly true in insects' main flight muscles, canonical examples of muscles thought to have a dedicated power function. However, in the moth (Manduca sexta), these muscles normally activate at a phase where the instantaneous slope of the power-phase curve is steep and well below maximum power. We provide four lines of evidence demonstrating that, contrary to the current paradigm, the moth's nervous system establishes significant control authority in these muscles through precise timing modulation: (i) left-right pairs of flight muscles normally fire precisely, within 0.5-0.6 ms of each other; (ii) during a yawing optomotor response, left-right muscle timing differences shift throughout a wider 8 ms timing window, enabling at least a 50 per cent left-right power differential; (iii) timing differences correlate with turning torque; and (iv) the downstroke power muscles alone causally account for 47 per cent of turning torque. To establish (iv), we altered muscle activation during intact behaviour by stimulating individual muscle potentials to impose left-right timing differences. Because many organisms also have muscles operating with high power-phase gains (Δ(power)/Δ(phase)), this motor control strategy may be ubiquitous in locomotor systems.

Abdicating power for control: a precision timing strategy to modulate function of flight power muscles

PubMed Central

Sponberg, S.; Daniel, T. L.

2012-01-01

Muscles driving rhythmic locomotion typically show strong dependence of power on the timing or phase of activation. This is particularly true in insects' main flight muscles, canonical examples of muscles thought to have a dedicated power function. However, in the moth (Manduca sexta), these muscles normally activate at a phase where the instantaneous slope of the power–phase curve is steep and well below maximum power. We provide four lines of evidence demonstrating that, contrary to the current paradigm, the moth's nervous system establishes significant control authority in these muscles through precise timing modulation: (i) left–right pairs of flight muscles normally fire precisely, within 0.5–0.6 ms of each other; (ii) during a yawing optomotor response, left—right muscle timing differences shift throughout a wider 8 ms timing window, enabling at least a 50 per cent left–right power differential; (iii) timing differences correlate with turning torque; and (iv) the downstroke power muscles alone causally account for 47 per cent of turning torque. To establish (iv), we altered muscle activation during intact behaviour by stimulating individual muscle potentials to impose left—right timing differences. Because many organisms also have muscles operating with high power–phase gains (Δpower/Δphase), this motor control strategy may be ubiquitous in locomotor systems. PMID:22833272

Time-Frequency Distribution Analyses of Ku-Band Radar Doppler Echo Signals

NASA Astrophysics Data System (ADS)

Bujaković, Dimitrije; Andrić, Milenko; Bondžulić, Boban; Mitrović, Srđan; Simić, Slobodan

2015-03-01

Real radar echo signals of a pedestrian, vehicle and group of helicopters are analyzed in order to maximize signal energy around central Doppler frequency in time-frequency plane. An optimization, preserving this concentration, is suggested based on three well-known concentration measures. Various window functions and time-frequency distributions were optimization inputs. Conducted experiments on an analytic and three real signals have shown that energy concentration significantly depends on used time-frequency distribution and window function, for all three used criteria.

The Clinical Picture. The Eyes: A Window into the Past

DTIC Science & Technology

2010-07-01

disseminated histoplasmosis, eye in- volvement manifests as panophthalmitis or uveitis , caused by yeast implantation. The finding of eye lesions typical of...Amsler grid.11 For POHS with choroidal neo- vascularization, treatment focuses on reducing the risk of vascular complications and includes oral...Antifungal treatment is not use- ful, as the lesions are not proven to be caused by active infection.10 Future treatments may include antiangio- genic drugs

Geochemical heterogeneity in a small, stratigraphically complex moraine aquifer system (Ontario, Canada): Interpretation of flow and recharge using multiple geochemical parameters

USGS Publications Warehouse

Stotler, R.L.; Frape, S.K.; El Mugammar, H.T.; Johnston, C.; Judd-Henrey, I.; Harvey, F.E.; Drimmie, R.; Jones, J.P.

2011-01-01

The Waterloo Moraine is a stratigraphically complex system and is the major water supply to the cities of Kitchener and Waterloo in Ontario, Canada. Despite over 30 years of investigation, no attempt has been made to unify existing geochemical data into a single database. A composite view of the moraine geochemistry has been created using the available geochemical information, and a framework created for geochemical data synthesis of other similar flow systems. Regionally, fluid chemistry is highly heterogeneous, with large variations in both water type and total dissolved solids content. Locally, upper aquifer units are affected by nitrate and chloride from fertilizer and road salt. Typical upper-aquifer fluid chemistry is dominated by calcium, magnesium, and bicarbonate, a result of calcite and dolomite dissolution. Evidence also suggests that ion exchange and diffusion from tills and bedrock units accounts for some elevated sodium concentrations. Locally, hydraulic "windows" cross connect upper and lower aquifer units, which are typically separated by a clay till. Lower aquifer units are also affected by dedolomitization, mixing with bedrock water, and locally, upward diffusion of solutes from the bedrock aquifers. A map of areas where aquifer units are geochemically similar was constructed to highlight areas with potential hydraulic windows. ?? 2010 Springer-Verlag.

USB Storage Device Forensics for Windows 10.

PubMed

Arshad, Ayesha; Iqbal, Waseem; Abbas, Haider

2018-05-01

Significantly increased use of USB devices due to their user-friendliness and large storage capacities poses various threats for many users/companies in terms of data theft that becomes easier due to their efficient mobility. Investigations for such data theft activities would require gathering critical digital information capable of recovering digital forensics artifacts like date, time, and device information. This research gathers three sets of registry and logs data: first, before insertion; second, during insertion; and the third, after removal of a USB device. These sets are analyzed to gather evidentiary information from Registry and Windows Event log that helps in tracking a USB device. This research furthers the prior research on earlier versions of Microsoft Windows and compares it with latest Windows 10 system. Comparison of Windows 8 and Windows 10 does not show much difference except for new subkey under USB Key in registry. However, comparison of Windows 7 with latest version indicates significant variances. © 2017 American Academy of Forensic Sciences.

Translucent windows: how uncertainty in competitive interactions impacts detection of community pattern.

PubMed

D'Andrea, Rafael; Ostling, Annette; O'Dwyer, James P

2018-06-01

Traits can provide a window into the mechanisms that maintain coexistence among competing species. Recent theory suggests that competitive interactions will lead to groups, or clusters, of species with similar traits. However, theoretical predictions typically assume complete knowledge of the map between competition and measured traits. These assumptions limit the plausible application of these patterns for inferring competitive interactions in nature. Here, we relax these restrictions and find that the clustering pattern is robust to contributions of unknown or unobserved niche axes. However, it may not be visible unless measured traits are close proxies for niche strategies. We conclude that patterns along single niche axes may reveal properties of interspecific competition in nature, but detecting these patterns requires natural history expertise firmly tying traits to niches. © 2018 John Wiley & Sons Ltd/CNRS.

Determination of injection molding process windows for optical lenses using response surface methodology.

PubMed

Tsai, Kuo-Ming; Wang, He-Yi

2014-08-20

This study focuses on injection molding process window determination for obtaining optimal imaging optical properties, astigmatism, coma, and spherical aberration using plastic lenses. The Taguchi experimental method was first used to identify the optimized combination of parameters and significant factors affecting the imaging optical properties of the lens. Full factorial experiments were then implemented based on the significant factors to build the response surface models. The injection molding process windows for lenses with optimized optical properties were determined based on the surface models, and confirmation experiments were performed to verify their validity. The results indicated that the significant factors affecting the optical properties of lenses are mold temperature, melt temperature, and cooling time. According to experimental data for the significant factors, the oblique ovals for different optical properties on the injection molding process windows based on melt temperature and cooling time can be obtained using the curve fitting approach. The confirmation experiments revealed that the average errors for astigmatism, coma, and spherical aberration are 3.44%, 5.62%, and 5.69%, respectively. The results indicated that the process windows proposed are highly reliable.

The windows of SETI - Frequency and time in the search for extraterrestrial intelligence

NASA Technical Reports Server (NTRS)

Oliver, Bernard M.

1987-01-01

Since interstellar travel is not economically possible on the time scale of a human lifetime, communication with extraterrestrials can be achieved only by sending some form of energy or matter across space; photons (electromagnetic waves) are best. Of particular interest to SETI is the region from about 1,000-60,000 MHz known as the free-space microwave window. During the course of NASA's Cyclops program, it was pointed out that the hydrogen and hydroxyl lines bounded a band in which there were no other known lines. The threatened loss of the microwave window to earth-based services is discussed.

Synchronization as a biological, psychological and social mechanism to create common time: A theoretical frame and a single case study.

PubMed

Bao, Yan; Pöppel, Ernst; Wang, Lingyan; Lin, Xiaoxiong; Yang, Taoxi; Avram, Mihai; Blautzik, Janusch; Paolini, Marco; Silveira, Sarita; Vedder, Aline; Zaytseva, Yuliya; Zhou, Bin

2015-12-01

Synchronizing neural processes, mental activities, and social interactions is considered to be fundamental for the creation of temporal order on the personal and interpersonal level. Several different types of synchronization are distinguished, and for each of them examples are given: self-organized synchronizations on the neural level giving rise to pre-semantically defined time windows of some tens of milliseconds and of approximately 3 s; time windows that are created by synchronizing different neural representations, as for instance in aesthetic appreciations or moral judgments; and synchronization of biological rhythms with geophysical cycles, like the circadian clock with the 24-hr rhythm of day and night. For the latter type of synchronization, an experiment is described that shows the importance of social interactions for sharing or avoiding common time. In a group study with four subjects being completely isolated together for 3 weeks from the external world, social interactions resulted both in intra- and interindividual circadian synchronization and desynchronization. A unique phenomenon in circadian regulation is described, the "beat phenomenon," which has been made visible by the interaction of two circadian rhythms with different frequencies in one body. The separation of the two physiological rhythms was the consequence of social interactions, that is, by the desire of a subject to share and to escape common time during different phases of the long-term experiment. The theoretical arguments on synchronization are summarized with the general statement: "Nothing in cognitive science makes sense except in the light of time windows." The hypothesis is forwarded that time windows that express discrete timing mechanisms in behavioral control and on the level of conscious experiences are the necessary bases to create cognitive order, and it is suggested that time windows are implemented by neural oscillations in different frequency domains. © 2015 The Institute of Psychology, Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

VO2 thermochromic smart window for energy savings and generation

PubMed Central

Zhou, Jiadong; Gao, Yanfeng; Zhang, Zongtao; Luo, Hongjie; Cao, Chuanxiang; Chen, Zhang; Dai, Lei; Liu, Xinling

2013-01-01

The ability to achieve energy saving in architectures and optimal solar energy utilisation affects the sustainable development of the human race. Traditional smart windows and solar cells cannot be combined into one device for energy saving and electricity generation. A VO2 film can respond to the environmental temperature to intelligently regulate infrared transmittance while maintaining visible transparency, and can be applied as a thermochromic smart window. Herein, we report for the first time a novel VO2-based smart window that partially utilises light scattering to solar cells around the glass panel for electricity generation. This smart window combines energy-saving and generation in one device, and offers potential to intelligently regulate and utilise solar radiation in an efficient manner. PMID:24157625

VO₂ thermochromic smart window for energy savings and generation.

PubMed

Zhou, Jiadong; Gao, Yanfeng; Zhang, Zongtao; Luo, Hongjie; Cao, Chuanxiang; Chen, Zhang; Dai, Lei; Liu, Xinling

2013-10-24

The ability to achieve energy saving in architectures and optimal solar energy utilisation affects the sustainable development of the human race. Traditional smart windows and solar cells cannot be combined into one device for energy saving and electricity generation. A VO2 film can respond to the environmental temperature to intelligently regulate infrared transmittance while maintaining visible transparency, and can be applied as a thermochromic smart window. Herein, we report for the first time a novel VO2-based smart window that partially utilises light scattering to solar cells around the glass panel for electricity generation. This smart window combines energy-saving and generation in one device, and offers potential to intelligently regulate and utilise solar radiation in an efficient manner.

Alternative Fuels Data Center: America's Largest Home Runs on Biodiesel in

Science.gov Websites

Coalition (Western North Carolina). Download QuickTime Video QuickTime (.mov) Download Windows Media Video Windows Media (.wmv) Video Download Help Text version See more videos provided by Clean Cities TV and Photo of a car Hydrogen Powers Fuel Cell Vehicles in California Nov. 18, 2017 Photo of a car Smart Car

Alternative Fuels Data Center: Rhode Island EV Initiative Adds Chargers

Science.gov Websites

Ocean State Clean Cities. Download QuickTime Video QuickTime (.mov) Download Windows Media Video Windows Media (.wmv) Video Download Help Text version See more videos provided by Clean Cities TV and Photo of a car Hydrogen Powers Fuel Cell Vehicles in California Nov. 18, 2017 Photo of a car Smart Car

Alternative Fuels Data Center: Worcester Regional Transit Authority Drives

Science.gov Websites

Clean Cities. Download QuickTime Video QuickTime (.mov) Download Windows Media Video Windows Media (.wmv ) Video Download Help Text version See more videos provided by Clean Cities TV and FuelEconomy.gov Fuel Cell Vehicles in California Nov. 18, 2017 Photo of a car Smart Car Shopping Nov. 4, 2017 Image of

Alternative Fuels Data Center: Propane Powers Airport Shuttles in New

Science.gov Websites

Clean Fuel Partnership. Download QuickTime Video QuickTime (.mov) Download Windows Media Video Windows Media (.wmv) Video Download Help Text version See more videos provided by Clean Cities TV and Vehicles in California Nov. 18, 2017 Photo of a car Smart Car Shopping Nov. 4, 2017 Photo of a truck

Automated variance reduction for MCNP using deterministic methods.

PubMed

Sweezy, J; Brown, F; Booth, T; Chiaramonte, J; Preeg, B

2005-01-01

In order to reduce the user's time and the computer time needed to solve deep penetration problems, an automated variance reduction capability has been developed for the MCNP Monte Carlo transport code. This new variance reduction capability developed for MCNP5 employs the PARTISN multigroup discrete ordinates code to generate mesh-based weight windows. The technique of using deterministic methods to generate importance maps has been widely used to increase the efficiency of deep penetration Monte Carlo calculations. The application of this method in MCNP uses the existing mesh-based weight window feature to translate the MCNP geometry into geometry suitable for PARTISN. The adjoint flux, which is calculated with PARTISN, is used to generate mesh-based weight windows for MCNP. Additionally, the MCNP source energy spectrum can be biased based on the adjoint energy spectrum at the source location. This method can also use angle-dependent weight windows.

ASTP (SA-210) Launch vehicle operational flight trajectory. Part 3: Final documentation

NASA Technical Reports Server (NTRS)

Carter, A. B.; Klug, G. W.; Williams, N. W.

1975-01-01

Trajectory data are presented for a nominal and two launch window trajectory simulations. These trajectories are designed to insert a manned Apollo spacecraft into a 150/167 km. (81/90 n. mi.) earth orbit inclined at 51.78 degrees for rendezvous with a Soyuz spacecraft, which will be orbiting at approximately 225 km. (121.5 n. mi.). The launch window allocation defined for this launch is 500 pounds of S-IVB stage propellant. The launch window opening trajectory simulation depicts the earliest launch time deviation from a planar flight launch which conforms to this constraint. The launch window closing trajectory simulation was developed for the more stringent Air Force Eastern Test Range (AFETR) flight azimuth restriction of 37.4 degrees east-of-north. These trajectories enclose a 12.09 minute launch window, pertinent features of which are provided in a tabulation. Planar flight data are included for mid-window reference.

Effects of the window openings on the micro-environmental condition in a school bus

NASA Astrophysics Data System (ADS)

Li, Fei; Lee, Eon S.; Zhou, Bin; Liu, Junjie; Zhu, Yifang

2017-10-01

School bus is an important micro-environment for children's health because the level of in-cabin air pollution can increase due to its own exhaust in addition to on-road traffic emissions. However, it has been challenging to understand the in-cabin air quality that is associated with complex airflow patterns inside and outside a school bus. This study conducted Computational Fluid Dynamics (CFD) modeling analyses to determine the effects of window openings on the self-pollution for a school bus. Infiltration through the window gaps is modeled by applying variable numbers of active computational cells as a function of the effective area ratio of the opening. The experimental data on ventilation rates from the literature was used to validate the model. Ultrafine particles (UFPs) and black carbon (BC) concentrations were monitored in ;real world; field campaigns using school buses. This modeling study examined the airflow pattern inside the school bus under four different types of side-window openings at 20, 40, and 60 mph (i.e., a total of 12 cases). We found that opening the driver's window could allow the infiltration of exhaust through window/door gaps in the back of school bus; whereas, opening windows in the middle of the school bus could mitigate this phenomenon. We also found that an increased driving speed (from 20 mph to 60 mph) could result in a higher ventilation rate (up to 3.4 times) and lower mean age of air (down to 0.29 time) inside the bus.

Dynamic subcellular imaging of cancer cell mitosis in the brain of live mice.

PubMed

Momiyama, Masashi; Suetsugu, Atsushi; Kimura, Hiroaki; Chishima, Takashi; Bouvet, Michael; Endo, Itaru; Hoffman, Robert M

2013-04-01

The ability to visualize cancer cell mitosis and apoptosis in the brain in real time would be of great utility in testing novel therapies. In order to achieve this goal, the cancer cells were labeled with green fluorescent protein (GFP) in the nucleus and red fluorescent protein (RFP) in the cytoplasm, such that mitosis and apoptosis could be clearly imaged. A craniotomy open window was made in athymic nude mice for real-time fluorescence imaging of implanted cancer cells growing in the brain. The craniotomy window was reversibly closed with a skin flap. Mitosis of the individual cancer cells were imaged dynamically in real time through the craniotomy-open window. This model can be used to evaluate brain metastasis and brain cancer at the subcellular level.

Percutaneous window chamber method for chronic intravital microscopy of sensor-tissue interactions.

PubMed

Koschwanez, Heidi E; Klitzman, Bruce; Reichert, W Monty

2008-11-01

A dorsal, two-sided skin-fold window chamber model was employed previously by Gough in glucose sensor research to characterize poorly understood physiological factors affecting sensor performance. We have extended this work by developing a percutaneous one-sided window chamber model for the rodent dorsum that offers both a larger subcutaneous area and a less restrictive tissue space than previous animal models. A surgical procedure for implanting a sensor into the subcutis beneath an acrylic window (15 mm diameter) is presented. Methods to quantify changes in the microvascular network and red blood cell perfusion around the sensors using noninvasive intravital microscopy and laser Doppler flowmetry are described. The feasibility of combining interstitial glucose monitoring from an implanted sensor with intravital fluorescence microscopy was explored using a bolus injection of fluorescein and dextrose to observe real-time mass transport of a small molecule at the sensor-tissue interface. The percutaneous window chamber provides an excellent model for assessing the influence of different sensor modifications, such as surface morphologies, on neovascularization using real-time monitoring of the microvascular network and tissue perfusion. However, the tissue response to an implanted sensor was variable, and some sensors migrated entirely out of the field of view and could not be observed adequately. A percutaneous optical window provides direct, real-time images of the development and dynamics of microvascular networks, microvessel patency, and fibrotic encapsulation at the tissue-sensor interface. Additionally, observing microvessels following combined bolus injections of a fluorescent dye and glucose in the local sensor environment demonstrated a valuable technique to visualize mass transport at the sensor surface.

Near real-time vaccine safety surveillance with partially accrued data.

PubMed

Greene, Sharon K; Kulldorff, Martin; Yin, Ruihua; Yih, W Katherine; Lieu, Tracy A; Weintraub, Eric S; Lee, Grace M

2011-06-01

The Vaccine Safety Datalink (VSD) Project conducts near real-time vaccine safety surveillance using sequential analytic methods. Timely surveillance is critical in identifying potential safety problems and preventing additional exposure before most vaccines are administered. For vaccines that are administered during a short period, such as influenza vaccines, timeliness can be improved by undertaking analyses while risk windows following vaccination are ongoing and by accommodating predictable and unpredictable data accrual delays. We describe practical solutions to these challenges, which were adopted by the VSD Project during pandemic and seasonal influenza vaccine safety surveillance in 2009/2010. Adjustments were made to two sequential analytic approaches. The Poisson-based approach compared the number of pre-defined adverse events observed following vaccination with the number expected using historical data. The expected number was adjusted for the proportion of the risk window elapsed and the proportion of inpatient data estimated to have accrued. The binomial-based approach used a self-controlled design, comparing the observed numbers of events in risk versus comparison windows. Events were included in analysis only if they occurred during a week that had already passed for both windows. Analyzing data before risk windows fully elapsed improved the timeliness of safety surveillance. Adjustments for data accrual lags were tailored to each data source and avoided biasing analyses away from detecting a potential safety problem, particularly early during surveillance. The timeliness of vaccine and drug safety surveillance can be improved by properly accounting for partially elapsed windows and data accrual delays. Copyright © 2011 John Wiley & Sons, Ltd.

Towards component-based validation of GATE: aspects of the coincidence processor

PubMed Central

Moraes, Eder R.; Poon, Jonathan K.; Balakrishnan, Karthikayan; Wang, Wenli; Badawi, Ramsey D.

2014-01-01

GATE is public domain software widely used for Monte Carlo simulation in emission tomography. Validations of GATE have primarily been performed on a whole-system basis, leaving the possibility that errors in one sub-system may be offset by errors in others. We assess the accuracy of the GATE PET coincidence generation sub-system in isolation, focusing on the options most closely modeling the majority of commercially available scanners. Independent coincidence generators were coded by teams at Toshiba Medical Research Unit (TMRU) and UC Davis. A model similar to the Siemens mCT scanner was created in GATE. Annihilation photons interacting with the detectors were recorded. Coincidences were generated using GATE, TMRU and UC Davis code and results compared to “ground truth” obtained from the history of the photon interactions. GATE was tested twice, once with every qualified single event opening a time window and initiating a coincidence check (the “multiple window method”), and once where a time window is opened and a coincidence check initiated only by the first single event to occur after the end of the prior time window (the “single window method”). True, scattered and random coincidences were compared. Noise equivalent count rates were also computed and compared. The TMRU and UC Davis coincidence generators agree well with ground truth. With GATE, reasonable accuracy can be obtained if the single window method option is chosen and random coincidences are estimated without use of the delayed coincidence option. However in this GATE version, other parameter combinations can result in significant errors. PMID:25240897

Solving the chemical master equation using sliding windows

PubMed Central

2010-01-01

Background The chemical master equation (CME) is a system of ordinary differential equations that describes the evolution of a network of chemical reactions as a stochastic process. Its solution yields the probability density vector of the system at each point in time. Solving the CME numerically is in many cases computationally expensive or even infeasible as the number of reachable states can be very large or infinite. We introduce the sliding window method, which computes an approximate solution of the CME by performing a sequence of local analysis steps. In each step, only a manageable subset of states is considered, representing a "window" into the state space. In subsequent steps, the window follows the direction in which the probability mass moves, until the time period of interest has elapsed. We construct the window based on a deterministic approximation of the future behavior of the system by estimating upper and lower bounds on the populations of the chemical species. Results In order to show the effectiveness of our approach, we apply it to several examples previously described in the literature. The experimental results show that the proposed method speeds up the analysis considerably, compared to a global analysis, while still providing high accuracy. Conclusions The sliding window method is a novel approach to address the performance problems of numerical algorithms for the solution of the chemical master equation. The method efficiently approximates the probability distributions at the time points of interest for a variety of chemically reacting systems, including systems for which no upper bound on the population sizes of the chemical species is known a priori. PMID:20377904

Invited Article: Single-shot THz detection techniques optimized for multidimensional THz spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Teo, Stephanie M.; Ofori-Okai, Benjamin K.; Werley, Christopher A.

Multidimensional spectroscopy at visible and infrared frequencies has opened a window into the transfer of energy and quantum coherences at ultrafast time scales. For these measurements to be performed in a manageable amount of time, one spectral axis is typically recorded in a single laser shot. An analogous rapid-scanning capability for THz measurements will unlock the multidimensional toolkit in this frequency range. Here, we first review the merits of existing single-shot THz schemes and discuss their potential in multidimensional THz spectroscopy. We then introduce improved experimental designs and noise suppression techniques for the two most promising methods: frequency-to-time encoding withmore » linear spectral interferometry and angle-to-time encoding with dual echelons. Both methods, each using electro-optic detection in the linear regime, were able to reproduce the THz temporal waveform acquired with a traditional scanning delay line. Although spectral interferometry had mediocre performance in terms of signal-to-noise, the dual echelon method was easily implemented and achieved the same level of signal-to-noise as the scanning delay line in only 4.5% of the laser pulses otherwise required (or 22 times faster). This reduction in acquisition time will compress day-long scans to hours and hence provides a practical technique for multidimensional THz measurements.« less

Invited Article: Single-shot THz detection techniques optimized for multidimensional THz spectroscopy.

PubMed

Teo, Stephanie M; Ofori-Okai, Benjamin K; Werley, Christopher A; Nelson, Keith A

2015-05-01

Multidimensional spectroscopy at visible and infrared frequencies has opened a window into the transfer of energy and quantum coherences at ultrafast time scales. For these measurements to be performed in a manageable amount of time, one spectral axis is typically recorded in a single laser shot. An analogous rapid-scanning capability for THz measurements will unlock the multidimensional toolkit in this frequency range. Here, we first review the merits of existing single-shot THz schemes and discuss their potential in multidimensional THz spectroscopy. We then introduce improved experimental designs and noise suppression techniques for the two most promising methods: frequency-to-time encoding with linear spectral interferometry and angle-to-time encoding with dual echelons. Both methods, each using electro-optic detection in the linear regime, were able to reproduce the THz temporal waveform acquired with a traditional scanning delay line. Although spectral interferometry had mediocre performance in terms of signal-to-noise, the dual echelon method was easily implemented and achieved the same level of signal-to-noise as the scanning delay line in only 4.5% of the laser pulses otherwise required (or 22 times faster). This reduction in acquisition time will compress day-long scans to hours and hence provides a practical technique for multidimensional THz measurements.

Window-Based Channel Impulse Response Prediction for Time-Varying Ultra-Wideband Channels.

PubMed

Al-Samman, A M; Azmi, M H; Rahman, T A; Khan, I; Hindia, M N; Fattouh, A

2016-01-01

This work proposes channel impulse response (CIR) prediction for time-varying ultra-wideband (UWB) channels by exploiting the fast movement of channel taps within delay bins. Considering the sparsity of UWB channels, we introduce a window-based CIR (WB-CIR) to approximate the high temporal resolutions of UWB channels. A recursive least square (RLS) algorithm is adopted to predict the time evolution of the WB-CIR. For predicting the future WB-CIR tap of window wk, three RLS filter coefficients are computed from the observed WB-CIRs of the left wk-1, the current wk and the right wk+1 windows. The filter coefficient with the lowest RLS error is used to predict the future WB-CIR tap. To evaluate our proposed prediction method, UWB CIRs are collected through measurement campaigns in outdoor environments considering line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios. Under similar computational complexity, our proposed method provides an improvement in prediction errors of approximately 80% for LOS and 63% for NLOS scenarios compared with a conventional method.

Window-Based Channel Impulse Response Prediction for Time-Varying Ultra-Wideband Channels

PubMed Central

Al-Samman, A. M.; Azmi, M. H.; Rahman, T. A.; Khan, I.; Hindia, M. N.; Fattouh, A.

2016-01-01

This work proposes channel impulse response (CIR) prediction for time-varying ultra-wideband (UWB) channels by exploiting the fast movement of channel taps within delay bins. Considering the sparsity of UWB channels, we introduce a window-based CIR (WB-CIR) to approximate the high temporal resolutions of UWB channels. A recursive least square (RLS) algorithm is adopted to predict the time evolution of the WB-CIR. For predicting the future WB-CIR tap of window wk, three RLS filter coefficients are computed from the observed WB-CIRs of the left wk−1, the current wk and the right wk+1 windows. The filter coefficient with the lowest RLS error is used to predict the future WB-CIR tap. To evaluate our proposed prediction method, UWB CIRs are collected through measurement campaigns in outdoor environments considering line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios. Under similar computational complexity, our proposed method provides an improvement in prediction errors of approximately 80% for LOS and 63% for NLOS scenarios compared with a conventional method. PMID:27992445

Strategies of statistical windows in PET image reconstruction to improve the user’s real time experience

NASA Astrophysics Data System (ADS)

Moliner, L.; Correcher, C.; Gimenez-Alventosa, V.; Ilisie, V.; Alvarez, J.; Sanchez, S.; Rodríguez-Alvarez, M. J.

2017-11-01

Nowadays, with the increase of the computational power of modern computers together with the state-of-the-art reconstruction algorithms, it is possible to obtain Positron Emission Tomography (PET) images in practically real time. These facts open the door to new applications such as radio-pharmaceuticals tracking inside the body or the use of PET for image-guided procedures, such as biopsy interventions, among others. This work is a proof of concept that aims to improve the user experience with real time PET images. Fixed, incremental, overlapping, sliding and hybrid windows are the different statistical combinations of data blocks used to generate intermediate images in order to follow the path of the activity in the Field Of View (FOV). To evaluate these different combinations, a point source is placed in a dedicated breast PET device and moved along the FOV. These acquisitions are reconstructed according to the different statistical windows, resulting in a smoother transition of positions for the image reconstructions that use the sliding and hybrid window.

Time-resolved two-window measurement of Wigner functions for coherent backscatter from a turbid medium

NASA Astrophysics Data System (ADS)

Reil, Frank; Thomas, John E.

2002-05-01

For the first time we are able to observe the time-resolved Wigner function of enhanced backscatter from a random medium using a novel two-window technique. This technique enables us to directly verify the phase-conjugating properties of random media. An incident divergent beam displays a convergent enhanced backscatter cone. We measure the joint position and momentum (x, p) distributions of the light field as a function of propagation time in the medium. The two-window technique allows us to independently control the resolutions for position and momentum, thereby surpassing the uncertainty limit associated with Fourier transform pairs. By using a low-coherence light source in a heterodyne detection scheme, we observe enhanced backscattering resolved by path length in the random medium, providing information about the evolution of optical coherence as a function of penetration depth in the random medium.

Dynamic programming-based hot spot identification approach for pedestrian crashes.

PubMed

Medury, Aditya; Grembek, Offer

2016-08-01

Network screening techniques are widely used by state agencies to identify locations with high collision concentration, also referred to as hot spots. However, most of the research in this regard has focused on identifying highway segments that are of concern to automobile collisions. In comparison, pedestrian hot spot detection has typically focused on analyzing pedestrian crashes in specific locations, such as at/near intersections, mid-blocks, and/or other crossings, as opposed to long stretches of roadway. In this context, the efficiency of the some of the widely used network screening methods has not been tested. Hence, in order to address this issue, a dynamic programming-based hot spot identification approach is proposed which provides efficient hot spot definitions for pedestrian crashes. The proposed approach is compared with the sliding window method and an intersection buffer-based approach. The results reveal that the dynamic programming method generates more hot spots with a higher number of crashes, while providing small hot spot segment lengths. In comparison, the sliding window method is shown to suffer from shortcomings due to a first-come-first-serve approach vis-à-vis hot spot identification and a fixed hot spot window length assumption. Copyright © 2016 Elsevier Ltd. All rights reserved.

Window Performance in Extreme Cold,

DTIC Science & Technology

1982-12-01

outdoor temperatures ranging between -40 and 20*F Alaska that have undergone an extensive window re- as shown in Table 2. We made these observations in...good predictor of when We made icing and condensation observations over moisture or ice would occur on a window pane. the temperature spectrum shown...tions were made during the daytime, it was often likely sashes or frames, and 4) vapor-loose indoor sashes that ATIo at the time of observation would

Design and comparison of laser windows for high-power lasers

NASA Astrophysics Data System (ADS)

Niu, Yanxiong; Liu, Wenwen; Liu, Haixia; Wang, Caili; Niu, Haisha; Man, Da

2014-11-01

High-power laser systems are getting more and more widely used in industry and military affairs. It is necessary to develop a high-power laser system which can operate over long periods of time without appreciable degradation in performance. When a high-energy laser beam transmits through a laser window, it is possible that the permanent damage is caused to the window because of the energy absorption by window materials. So, when we design a high-power laser system, a suitable laser window material must be selected and the laser damage threshold of the window must be known. In this paper, a thermal analysis model of high-power laser window is established, and the relationship between the laser intensity and the thermal-stress field distribution is studied by deducing the formulas through utilizing the integral-transform method. The influence of window radius, thickness and laser intensity on the temperature and stress field distributions is analyzed. Then, the performance of K9 glass and the fused silica glass is compared, and the laser-induced damage mechanism is analyzed. Finally, the damage thresholds of laser windows are calculated. The results show that compared with K9 glass, the fused silica glass has a higher damage threshold due to its good thermodynamic properties. The presented theoretical analysis and simulation results are helpful for the design and selection of high-power laser windows.

Novel windowing technique realized in FPGA for radar system

NASA Astrophysics Data System (ADS)

Escamilla-Hernandez, E.; Kravchenko, V. F.; Ponomaryov, V. I.; Ikuo, Arai

2006-02-01

To improve the weak target detection ability in radar applications a pulse compression is usually used that in the case linear FM modulation can improve the SNR. One drawback in here is that it can add the range side-lobes in reflectivity measurements. Using weighting window processing in time domain it is possible to decrease significantly the side-lobe level (SLL) and resolve small or low power targets those are masked by powerful ones. There are usually used classical windows such as Hamming, Hanning, etc. in window processing. Additionally to classical ones in this paper we also use a novel class of windows based on atomic functions (AF) theory. For comparison of simulation and experimental results we applied the standard parameters, such as coefficient of amplification, maximum level of side-lobe, width of main lobe, etc. To implement the compression-windowing model on hardware level it has been employed FPGA. This work aims at demonstrating a reasonably flexible implementation of FM-linear signal, pulse compression and windowing employing FPGA's. Classical and novel AF window technique has been investigated to reduce the SLL taking into account the noise influence and increasing the detection ability of the small or weak targets in the imaging radar. Paper presents the experimental hardware results of windowing in pulse compression radar resolving several targets for rectangular, Hamming, Kaiser-Bessel, (see manuscript for formula) functions windows. The windows created by use the atomic functions offer sufficiently better decreasing of the SLL in case of noise presence and when we move away of the main lobe in comparison with classical windows.

Atypical neurophysiology underlying episodic and semantic memory in adults with autism spectrum disorder.

PubMed

Massand, Esha; Bowler, Dermot M

2015-02-01

Individuals with autism spectrum disorder (ASD) show atypicalities in episodic memory (Boucher et al. in Psychological Bulletin, 138 (3), 458-496, 2012). We asked participants to recall the colours of a set of studied line drawings (episodic judgement), or to recognize line drawings alone (semantic judgement). Cycowicz et al. (Journal of Experimental Child Psychology, 65, 171-237, 2001) found early (300 ms onset) posterior old-new event-related potential effects for semantic judgements in typically developing (TD) individuals, and occipitally focused negativity (800 ms onset) for episodic judgements. Our results replicated findings in TD individuals and demonstrate attenuated early old-new effects in ASD. Late posterior negativity was present in the ASD group, but was not specific to this time window. This non-specificity may contribute to the atypical episodic memory judgements characteristic of individuals with ASD.

Identifying States of a Financial Market

NASA Astrophysics Data System (ADS)

Münnix, Michael C.; Shimada, Takashi; Schäfer, Rudi; Leyvraz, Francois; Seligman, Thomas H.; Guhr, Thomas; Stanley, H. Eugene

2012-09-01

The understanding of complex systems has become a central issue because such systems exist in a wide range of scientific disciplines. We here focus on financial markets as an example of a complex system. In particular we analyze financial data from the S&P 500 stocks in the 19-year period 1992-2010. We propose a definition of state for a financial market and use it to identify points of drastic change in the correlation structure. These points are mapped to occurrences of financial crises. We find that a wide variety of characteristic correlation structure patterns exist in the observation time window, and that these characteristic correlation structure patterns can be classified into several typical ``market states''. Using this classification we recognize transitions between different market states. A similarity measure we develop thus affords means of understanding changes in states and of recognizing developments not previously seen.

Identifying states of a financial market.

PubMed

Münnix, Michael C; Shimada, Takashi; Schäfer, Rudi; Leyvraz, Francois; Seligman, Thomas H; Guhr, Thomas; Stanley, H Eugene

2012-01-01

The understanding of complex systems has become a central issue because such systems exist in a wide range of scientific disciplines. We here focus on financial markets as an example of a complex system. In particular we analyze financial data from the S&P 500 stocks in the 19-year period 1992-2010. We propose a definition of state for a financial market and use it to identify points of drastic change in the correlation structure. These points are mapped to occurrences of financial crises. We find that a wide variety of characteristic correlation structure patterns exist in the observation time window, and that these characteristic correlation structure patterns can be classified into several typical "market states". Using this classification we recognize transitions between different market states. A similarity measure we develop thus affords means of understanding changes in states and of recognizing developments not previously seen.

Mass univariate analysis of event-related brain potentials/fields I: a critical tutorial review.

PubMed

Groppe, David M; Urbach, Thomas P; Kutas, Marta

2011-12-01

Event-related potentials (ERPs) and magnetic fields (ERFs) are typically analyzed via ANOVAs on mean activity in a priori windows. Advances in computing power and statistics have produced an alternative, mass univariate analyses consisting of thousands of statistical tests and powerful corrections for multiple comparisons. Such analyses are most useful when one has little a priori knowledge of effect locations or latencies, and for delineating effect boundaries. Mass univariate analyses complement and, at times, obviate traditional analyses. Here we review this approach as applied to ERP/ERF data and four methods for multiple comparison correction: strong control of the familywise error rate (FWER) via permutation tests, weak control of FWER via cluster-based permutation tests, false discovery rate control, and control of the generalized FWER. We end with recommendations for their use and introduce free MATLAB software for their implementation. Copyright © 2011 Society for Psychophysiological Research.

Aircraft stress sequence development: A complex engineering process made simple

NASA Technical Reports Server (NTRS)

Schrader, K. H.; Butts, D. G.; Sparks, W. A.

1994-01-01

Development of stress sequences for critical aircraft structure requires flight measured usage data, known aircraft loads, and established relationships between aircraft flight loads and structural stresses. Resulting cycle-by-cycle stress sequences can be directly usable for crack growth analysis and coupon spectra tests. Often, an expert in loads and spectra development manipulates the usage data into a typical sequence of representative flight conditions for which loads and stresses are calculated. For a fighter/trainer type aircraft, this effort is repeated many times for each of the fatigue critical locations (FCL) resulting in expenditure of numerous engineering hours. The Aircraft Stress Sequence Computer Program (ACSTRSEQ), developed by Southwest Research Institute under contract to San Antonio Air Logistics Center, presents a unique approach for making complex technical computations in a simple, easy to use method. The program is written in Microsoft Visual Basic for the Microsoft Windows environment.

Associations among multiple markers and complex disease: models, algorithms, and applications.

PubMed

Assimes, Themistocles L; Olshen, Adam B; Narasimhan, Balasubramanian; Olshen, Richard A

2008-01-01

This chapter is a report on collaborations among its authors and others over many years. It devolves from our goal of understanding genes, their main and epistatic effects combined with interactions involving demographic and environmental features also, as together they predict genetically complex diseases. Thus, our goal is "association." Particular phenotypes of interest to us are hypertension, insulin resistance, angina, and myocardial infarction. Prediction of complex disease is notoriously difficult, though it would be made easier were we given strand-specific information on genotype. Unfortunately, with current technology, genotypic information comes to us "unphased." While obviously we have strand-specific information when genotype is homozygous, we do not have such information when genotype is heterozygous. To summarize, the ultimate goals of approaches we provide is to predict phenotype, typically untoward or not, within a specific window of time. Our approach is neither through linkage nor from finding haplotype frequencies per se.

Childhood Stuttering – Where are we and Where are we going?

PubMed Central

Smith, Anne; Weber, Christine

2017-01-01

Remarkable progress has been made over the past two decades in expanding our understanding of the behavioral, peripheral physiological, and central neurophysiological bases of stuttering in early childhood. It is clear that stuttering is a neurodevelopmental disorder characterized by atypical development of speech motor planning and execution networks. The speech motor system must interact in complex ways with neural systems mediating language, other cognitive, and emotional processes. During the time window when stuttering typically appears and follows its path to either recovery or persistence, all of these neurobehavioral systems are undergoing rapid and dramatic developmental changes. We summarize our current understanding of the various developmental trajectories relevant for the understanding of stuttering in early childhood. We also present theoretical and experimental approaches that we believe will be optimal for even more rapid progress toward developing better and more targeted treatment for stuttering in the preschool children who are more likely to persist in stuttering. PMID:27701705

climwin: An R Toolbox for Climate Window Analysis.

PubMed

Bailey, Liam D; van de Pol, Martijn

2016-01-01

When studying the impacts of climate change, there is a tendency to select climate data from a small set of arbitrary time periods or climate windows (e.g., spring temperature). However, these arbitrary windows may not encompass the strongest periods of climatic sensitivity and may lead to erroneous biological interpretations. Therefore, there is a need to consider a wider range of climate windows to better predict the impacts of future climate change. We introduce the R package climwin that provides a number of methods to test the effect of different climate windows on a chosen response variable and compare these windows to identify potential climate signals. climwin extracts the relevant data for each possible climate window and uses this data to fit a statistical model, the structure of which is chosen by the user. Models are then compared using an information criteria approach. This allows users to determine how well each window explains variation in the response variable and compare model support between windows. climwin also contains methods to detect type I and II errors, which are often a problem with this type of exploratory analysis. This article presents the statistical framework and technical details behind the climwin package and demonstrates the applicability of the method with a number of worked examples.

Alternative Fuels Data Center: Kentucky Charges Forward with All-Electric

Science.gov Websites

Partnership. Download QuickTime Video QuickTime (.mov) Download Windows Media Video Windows Media (.wmv) Video Fuel Cell Vehicles in California Nov. 18, 2017 Photo of a car Smart Car Shopping Nov. 4, 2017 Image of Photo of a truck Natural Gas Fuels School Buses and Refuse Trucks in Tulsa, Oklahoma Feb. 18, 2017 Photo

Study of wavefront error and polarization of a side mounted infrared window

NASA Astrophysics Data System (ADS)

Liu, Jiaguo; Li, Lin; Hu, Xinqi; Yu, Xin

2008-03-01

The wavefront error and polarization of a side mounted infrared window made of ZnS are studied. The Infrared windows suffer from temperature gradient and stress during their launch process. Generally, the gradient in temperature changes the refractive index of the material whereas stress produces deformation and birefringence. In this paper, a thermal finite element analysis (FEA) of an IR window is presented. For this purpose, we employed an FEA program Ansys to obtain the time-varying temperature field. The deformation and stress of the window are derived from a structural FEA with the aerodynamic force and the temperature field previously obtained as being the loads. The deformation, temperature field, stress field, ray tracing and Jones Calculus are used to calculate the wavefront error and the change of polarization state.

Implementing and Bounding a Cascade Heuristic for Large-Scale Optimization

DTIC Science & Technology

2017-06-01

solving the monolith, we develop a method for producing lower bounds to the optimal objective function value. To do this, we solve a new integer...as developing and analyzing methods for producing lower bounds to the optimal objective function value of the seminal problem monolith, which this...length of the window decreases, the end effects of the model typically increase (Zerr, 2016). There are four primary methods for correcting end

Window of Opportunity: Mitigating Threats from Disruptive Technologies Before Widespread Adoption

DTIC Science & Technology

2014-09-01

involved. A contemporary example of this is the emergence of online peer-to-peer payment systems like Bitcoin . Bitcoin was left to proliferate...collapse of Mt. Gox, a bitcoin exchange.195 The problem with this method of protection is that governmental based actions are typically a tediously slow...195 Mt. Gox was one of the foremost bitcoin exchange networks, and it collapsed when it was hacked and lost the

Project LOLA or Lunar Orbit and Landing Approach was a simulator built at Langley

NASA Image and Video Library

1961-07-23

Test subject sitting at the controls: Project LOLA or Lunar Orbit and Landing Approach was a simulator built at Langley to study problems related to landing on the lunar surface. It was a complex project that cost nearly $2 million dollars. James Hansen wrote: "This simulator was designed to provide a pilot with a detailed visual encounter with the lunar surface; the machine consisted primarily of a cockpit, a closed-circuit TV system, and four large murals or scale models representing portions of the lunar surface as seen from various altitudes. The pilot in the cockpit moved along a track past these murals which would accustom him to the visual cues for controlling a spacecraft in the vicinity of the moon. Unfortunately, such a simulation--although great fun and quite aesthetic--was not helpful because flight in lunar orbit posed no special problems other than the rendezvous with the LEM, which the device did not simulate. Not long after the end of Apollo, the expensive machine was dismantled." (p. 379) Ellis J. White further described this simulator in his paper , "Discussion of Three Typical Langley Research Center Simulation Programs," (Paper presented at the Eastern Simulation Council (EAI's Princeton Computation Center), Princeton, NJ, October 20, 1966.) "A typical mission would start with the first cart positioned on model 1 for the translunar approach and orbit establishment. After starting the descent, the second cart is readied on model 2 and, at the proper time, when superposition occurs, the pilot's scene is switched from model 1 to model 2. then cart 1 is moved to and readied on model 3. The procedure continues until an altitude of 150 feet is obtained. The cabin of the LM vehicle has four windows which represent a 45 degree field of view. The projection screens in front of each window represent 65 degrees which allows limited head motion before the edges of the display can be seen. The lunar scene is presented to the pilot by rear projection on the screens with four Schmidt television projectors. The attitude orientation of the vehicle is represented by changing the lunar scene through the portholes determined by the scan pattern of four orthicons. The stars are front projected onto the upper three screens with a four-axis starfield generation (starball) mounted over the cabin and there is a separate starball for the low window." -- Published in James R. Hansen, Spaceflight Revolution: NASA Langley Research Center From Sputnik to Apollo, (Washington: NASA, 1995), p. 379.

The Role of Daylighting in Skilled Nursing Short-Term Rehabilitation Facilities.

PubMed

Gharaveis, Arsalan; Shepley, Mardelle McCuskey; Gaines, Kristi

2016-01-01

The aim of this study is to investigate the best placement of windows in short-term rehabilitation facilities in terms of daylighting and outdoor views by exploring the impact of windows on resident perception of stress, mood, activities, and satisfaction. The physiological and psychological benefits of daylighting have made it an increasingly important topic in multidisciplinary research. Although multiple studies have been written about the impact of daylight on physiological responses, few investigations have been made into the nonvisual effects related to resident mood, satisfaction, and stress level. In addition, researchers typically propose recommendations for quantitative aspects of illuminance, rather than addressing the behavioural outcomes. A combination of qualitative and quantitative methodologies were used to address the research questions. Thirty-four participants, who were living temporarily in the inpatient rehabilitation units of two skilled nursing facilities, were subjects in semistructured interviews and a 7-question 5-scale survey. While residents expressed the need to have direct visual access to the outdoors, they indicated that daylight was of even higher benefit. Additionally, they noted that size and location of windows impacted their stress levels, moods, and activities. More than half of the facility residents reported changing their postures for either better outdoor views or less light disturbance while sleeping. The results of this study emphasize the importance of daylighting for residents in rehabilitation units. Architects should acknowledge the role of daylighting and window views in the design of rehabilitation facilities. © The Author(s) 2015.

High Reliability R-10 Windows Using Vacuum Insulating Glass Units

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stark, David

2012-08-16

The objective of this effort was for EverSealed Windows (“EverSealed” or “ESW”) to design, assemble, thermally and environmentally test and demonstrate a Vacuum Insulating Glass Unit (“VIGU” or “VIG”) that would enable a whole window to meet or exceed the an R-10 insulating value (U-factor ≤ 0.1). To produce a VIGU that could withstand any North American environment, ESW believed it needed to design, produce and use a flexible edge seal system. This is because a rigid edge seal, used by all other know VIG producers and developers, limits the size and/or thermal environment of the VIG to where themore » unit is not practical for typical IG sizes and cannot withstand severe outdoor environments. The rigid-sealed VIG’s use would be limited to mild climates where it would not have a reasonable economic payback when compared to traditional double-pane or triple-pane IGs. ESW’s goals, in addition to achieving a sufficiently high R-value to enable a whole window to achieve R-10, included creating a VIG design that could be produced for a cost equal to or lower than a traditional triple-pane IG (low-e, argon filled). ESW achieved these goals. EverSealed produced, tested and demonstrated a flexible edge-seal VIG that had an R-13 insulating value and the edge-seal system durability to operate reliably for at least 40 years in the harshest climates of North America.« less

DPOAEs in infants developmentally exposed to PCBs show two differently time spaced exposure sensitive windows.

PubMed

Koštiaková, Vladimíra; Moleti, Arturo; Wimmerová, Soňa; Jusko, Todd A; Palkovičová Murínová, Ľubica; Sisto, Renata; Richterová, Denisa; Kováč, Ján; Čonka, Kamil; Patayová, Henrieta; Tihányi, Juraj; Trnovec, Tomáš

2016-10-01

The study aim was to identify the timing of sensitive windows for ototoxicity related to perinatal exposure to PCBs. A total of 351 and 214 children from a birth cohort in eastern Slovakia underwent otoacoustic testing at 45 and 72 months, respectively, and distortion product otoacoustic emissions (DPOAEs) at 11 frequencies were recorded. Cord and child 6-, 16-, 45-, and 72- month blood samples were analyzed for PCB 153 concentration. The PCB 153 concentration-time profiles were approximated with a system model to calculate area under the PCB*time curves (AUCs) for specific time intervals (3 and 6 months for 45 and 72 months data, respectively). DPOAE amplitudes were correlated (Spearman) with cord serum PCB and AUCs, markers of prenatal and postnatal exposure, respectively. Two exposure critical windows were identified in infants, the first related to prenatal and early postnatal and the second to postnatal exposure to PCBs. Our data have shown tonotopicity, sexual dimorphism, and asymmetry in ototoxicity of PCBs. Copyright © 2016. Published by Elsevier Ltd.

Real-time image sequence segmentation using curve evolution

NASA Astrophysics Data System (ADS)

Zhang, Jun; Liu, Weisong

2001-04-01

In this paper, we describe a novel approach to image sequence segmentation and its real-time implementation. This approach uses the 3D structure tensor to produce a more robust frame difference signal and uses curve evolution to extract whole objects. Our algorithm is implemented on a standard PC running the Windows operating system with video capture from a USB camera that is a standard Windows video capture device. Using the Windows standard video I/O functionalities, our segmentation software is highly portable and easy to maintain and upgrade. In its current implementation on a Pentium 400, the system can perform segmentation at 5 frames/sec with a frame resolution of 160 by 120.

Development of novel murine mammary imaging windows to examine wound healing effects on leukocyte trafficking in mammary tumors with intravital imaging

PubMed Central

Sobolik, Tammy; Su, Ying-Jun; Ashby, Will; Schaffer, David K.; Wells, Sam; Wikswo, John P.; Zijlstra, Andries; Richmond, Ann

2016-01-01

ABSTRACT We developed mammary imaging windows (MIWs) to evaluate leukocyte infiltration and cancer cell dissemination in mouse mammary tumors imaged by confocal microscopy. Previous techniques relied on surgical resection of a skin flap to image the tumor microenvironment restricting imaging time to a few hours. Utilization of mammary imaging windows offers extension of intravital imaging of the tumor microenvironment. We have characterized strengths and identified some previously undescribed potential weaknesses of MIW techniques. Through iterative enhancements of a transdermal portal we defined conditions for improved quality and extended confocal imaging time for imaging key cell-cell interactions in the tumor microenvironment. PMID:28243517

Development of novel murine mammary imaging windows to examine wound healing effects on leukocyte trafficking in mammary tumors with intravital imaging.

PubMed

Sobolik, Tammy; Su, Ying-Jun; Ashby, Will; Schaffer, David K; Wells, Sam; Wikswo, John P; Zijlstra, Andries; Richmond, Ann

2016-01-01

We developed mammary imaging windows (MIWs) to evaluate leukocyte infiltration and cancer cell dissemination in mouse mammary tumors imaged by confocal microscopy. Previous techniques relied on surgical resection of a skin flap to image the tumor microenvironment restricting imaging time to a few hours. Utilization of mammary imaging windows offers extension of intravital imaging of the tumor microenvironment. We have characterized strengths and identified some previously undescribed potential weaknesses of MIW techniques. Through iterative enhancements of a transdermal portal we defined conditions for improved quality and extended confocal imaging time for imaging key cell-cell interactions in the tumor microenvironment.

Latitudinal and photic effects on diel foraging and predation risk in freshwater pelagic ecosystems

USGS Publications Warehouse

Hansen, Adam G.; Beauchamp, David A.

2014-01-01

1. Clark & Levy (American Naturalist, 131, 1988, 271–290) described an antipredation window for smaller planktivorous fish during crepuscular periods when light permits feeding on zooplankton, but limits visual detection by piscivores. Yet, how the window is influenced by the interaction between light regime, turbidity and cloud cover over a broad latitudinal gradi- ent remains unexplored. 2. We evaluated how latitudinal and seasonal shifts in diel light regimes alter the foraging- risk environment for visually feeding planktivores and piscivores across a natural range of turbidities and cloud covers. Pairing a model of aquatic visual feeding with a model of sun and moon illuminance, we estimated foraging rates of an idealized planktivore and piscivore over depth and time across factorial combinations of latitude (0–70°), turbidity (01–5 NTU) and cloud cover (clear to overcast skies) during the summer solstice and autumnal equinox. We evaluated the foraging-risk environment based on changes in the magnitude, duration and peak timing of the antipredation window. 3. The model scenarios generated up to 10-fold shifts in magnitude, 24-fold shifts in duration and 55-h shifts in timing of the peak antipredation window. The size of the window increased with latitude. This pattern was strongest during the solstice. In clear water at low turbidity (01–05 NTU), peaks in the magnitude and duration of the window formed at 57–60° latitude, before falling to near zero as surface waters became saturated with light under a midnight sun and clear skies at latitudes near 70°. Overcast dampened the midnight sun enough to allow larger windows to form in clear water at high latitudes. Conversely, at turbidities ≥2 NTU, greater reductions in the visual range of piscivores than planktivores created a window for long periods at high latitudes. Latitudinal dependencies were essentially lost during the equinox, indicating a progressive compression of the window from early summer into autumn. 4. Model results show that diel-seasonal foraging and predation risk in freshwater pelagic ecosystems changes considerably with latitude, turbidity and cloud cover. These changes alter the structure of pelagic predator–prey interactions, and in turn, the broader role of pelagic consumers in habitat coupling in lakes. 

High-Temperature Optical Window Design

NASA Technical Reports Server (NTRS)

Roeloffs, Norman; Taranto, Nick

1995-01-01

A high-temperature optical window is essential to the optical diagnostics of high-temperature combustion rigs. Laser Doppler velocimetry, schlieren photography, light sheet visualization, and laser-induced fluorescence spectroscopy are a few of the tests that require optically clear access to the combustor flow stream. A design was developed for a high-temperature window that could withstand the severe environment of the NASA Lewis 3200 F Lean Premixed Prevaporized (LPP) Flame Tube Test Rig. The development of this design was both time consuming and costly. This report documents the design process and the lessons learned, in an effort to reduce the cost of developing future designs for high-temperature optical windows.

The energy radiated by the 26 December 2004 Sumatra-Andaman earthquake estimated from 10-minute P-wave windows

USGS Publications Warehouse

Choy, G.L.; Boatwright, J.

2007-01-01

The rupture process of the Mw 9.1 Sumatra-Andaman earthquake lasted for approximately 500 sec, nearly twice as long as the teleseismic time windows between the P and PP arrival times generally used to compute radiated energy. In order to measure the P waves radiated by the entire earthquake, we analyze records that extend from the P-wave to the S-wave arrival times from stations at distances ?? >60??. These 8- to 10-min windows contain the PP, PPP, and ScP arrivals, along with other multiply reflected phases. To gauge the effect of including these additional phases, we form the spectral ratio of the source spectrum estimated from extended windows (between TP and TS) to the source spectrum estimated from normal windows (between TP and TPP). The extended windows are analyzed as though they contained only the P-pP-sP wave group. We analyze four smaller earthquakes that occurred in the vicinity of the Mw 9.1 mainshock, with similar depths and focal mechanisms. These smaller events range in magnitude from an Mw 6.0 aftershock of 9 January 2005 to the Mw 8.6 Nias earthquake that occurred to the south of the Sumatra-Andaman earthquake on 28 March 2005. We average the spectral ratios for these four events to obtain a frequency-dependent operator for the extended windows. We then correct the source spectrum estimated from the extended records of the 26 December 2004 mainshock to obtain a complete or corrected source spectrum for the entire rupture process (???600 sec) of the great Sumatra-Andaman earthquake. Our estimate of the total seismic energy radiated by this earthquake is 1.4 ?? 1017 J. When we compare the corrected source spectrum for the entire earthquake to the source spectrum from the first ???250 sec of the rupture process (obtained from normal teleseismic windows), we find that the mainshock radiated much more seismic energy in the first half of the rupture process than in the second half, especially over the period range from 3 sec to 40 sec.

Factors influencing the efficacy of round window dexamethasone protection of residual hearing post-cochlear implant surgery.

PubMed

Chang, Andrew; Eastwood, Hayden; Sly, David; James, David; Richardson, Rachael; O'Leary, Stephen

2009-09-01

To protect hearing in an experimental model of cochlear implantation by the application of dexamethasone to the round window prior to surgery. The present study examined the dosage and timing relationships required to optimise the hearing protection. Dexamethasone or saline (control) was absorbed into a pledget of the carboxymethylcellulose and hyaluronic acid and applied to the round window of the guinea pig prior to cochlear implantation. The treatment groups were 2% w/v dexamethasone for 30, 60 and 120min; 20% dexamethasone applied for 30min. Auditory sensitivity was determined pre-operatively, and at 1 week after surgery, with pure-tone auditory brainstem response audiometry (2-32kHz). Cochlear implantation was performed via a cochleostomy drilled into the basal turn of the cochlea, into which a miniature cochlear implant dummy electrode was inserted using soft-surgery techniques. ABR thresholds were elevated after cochlear implantation, maximally at 32kHz and to a lesser extent at lower frequencies. Thresholds were less elevated after dexamethasone treatment, and the hearing protection improved when 2% dexamethasone was applied to the round window for longer periods of time prior to implantation. The time that dexamethasone need be applied to achieve hearing protection could be reduced by increasing the concentration of steroid, with a 20% application for 30min achieving similar levels of protection to a 60min application of 2% dexamethasone. Hearing protection is improved by increasing the time that dexamethasone is applied to the round window prior to cochlear implantation, and the waiting time can be reduced by increasing the steroid concentration. These results suggest that the diffusion dexamethasone through the cochlea is the prime determinant of the extent of hearing protection.

Infrared Absorption Spectroscopy and Chemical Kinetics of Free Radicals. Final Performance Report, August 1, 1985--July 31, 1994

DOE R&D Accomplishments Database

Curl, R. F.; Glass, G. P.

1995-06-01

This research was directed at the detection, monitoring, and study (by infrared absorption spectroscopy) of the chemical kinetic behavior of small free radical species thought to be important intermediates in combustion. The work typically progressed from the detection and analysis of the infrared spectrum of combustion radical to the utilization of the infrared spectrum thus obtained in the investigation of chemical kinetics of the radical species. The methodology employed was infrared kinetic spectroscopy. In this technique the radical is produced by UV flash photolysis using an excimer laser and then its transient infrared absorption is observed using a single frequency cw laser as the source of the infrared probe light. When the probe laser frequency is near the center of an absorption line of the radical produced by the flash, the transient infrared absorption rises rapidly and then decays as the radical reacts with the precursor or with substances introduced for the purpose of studying the reaction kinetics or with itself. The decay times observed in these studies varied from less than one microsecond to more than one millisecond. By choosing appropriate time windows after the flash and the average infrared detector signal in a window as data channels, the infrared spectrum of the radical may be obtained. By locking the infrared probe laser to the center of the absorption line and measuring the rate of decay of the transient infrared absorption signal as the chemical composition of the gas mixture is varied, the chemical kinetics of the radical may be investigated. In what follows the systems investigated and the results obtained are outlined.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodríguez, C.A.; Sandoval-Paz, M.G.; Cabello, G.

Highlights: • High quality ZnS thin films have been deposited by chemical bath deposition technique from a non-toxic precursor’s solution. • Nanocrystalline ZnS thin films with large band gap energy were synthesized without using ammonia. • Evidence that the growing of the thin films is carried out by means of hydroxide mechanism was found. • The properties of these ZnS thin films are similar and in some cases better than the corresponding ones produced using toxic precursors such as ammonia. - Abstract: In solar cells, ZnS window layer deposited by chemical bath technique can reach the highest conversion efficiency; however,more » precursors used in the process normally are materials highly volatile, toxic and harmful to the environment and health (typically ammonia and hydrazine). In this work the characterization of ZnS thin films deposited by chemical bath in a non-toxic alkaline solution is reported. The effect of deposition technique (growth in several times) on the properties of the ZnS thin film was studied. The films exhibited a high percentage of optical transmission (greater than 80%); as the deposition time increased a decreasing in the band gap values from 3.83 eV to 3.71 eV was observed. From chemical analysis, the presence of ZnS and Zn(OH){sub 2} was identified and X-ray diffraction patterns exhibited a clear peak corresponding to ZnS hexagonal phase (1 0 3) plane, which was confirmed by electron diffraction patterns. From morphological studies, compact samples with well-defined particles, low roughness, homogeneous and pinhole-free in the surface were observed. From obtained results, it is evident that deposits of ZnS–CBD using a non-toxic solution are suitable as window layer for TFSC.« less

Implementation of system intelligence in a 3-tier telemedicine/PACS hierarchical storage management system

NASA Astrophysics Data System (ADS)

Chao, Woodrew; Ho, Bruce K. T.; Chao, John T.; Sadri, Reza M.; Huang, Lu J.; Taira, Ricky K.

1995-05-01

Our tele-medicine/PACS archive system is based on a three-tier distributed hierarchical architecture, including magnetic disk farms, optical jukebox, and tape jukebox sub-systems. The hierarchical storage management (HSM) architecture, built around a low cost high performance platform [personal computers (PC) and Microsoft Windows NT], presents a very scaleable and distributed solution ideal for meeting the needs of client/server environments such as tele-medicine, tele-radiology, and PACS. These image based systems typically require storage capacities mirroring those of film based technology (multi-terabyte with 10+ years storage) and patient data retrieval times at near on-line performance as demanded by radiologists. With the scaleable architecture, storage requirements can be easily configured to meet the needs of the small clinic (multi-gigabyte) to those of a major hospital (multi-terabyte). The patient data retrieval performance requirement was achieved by employing system intelligence to manage migration and caching of archived data. Relevant information from HIS/RIS triggers prefetching of data whenever possible based on simple rules. System intelligence embedded in the migration manger allows the clustering of patient data onto a single tape during data migration from optical to tape medium. Clustering of patient data on the same tape eliminates multiple tape loading and associated seek time during patient data retrieval. Optimal tape performance can then be achieved by utilizing the tape drives high performance data streaming capabilities thereby reducing typical data retrieval delays associated with streaming tape devices.

Delay of cognitive gamma responses in Alzheimer's disease

PubMed Central

Başar, Erol; Emek-Savaş, Derya Durusu; Güntekin, Bahar; Yener, Görsev G.

2016-01-01

Event-related oscillations (EROs) reflect cognitive brain dynamics, while sensory-evoked oscillations (SEOs) reflect sensory activities. Previous reports from our lab have shown that those with Alzheimer's disease (AD) or mild cognitive impairment (MCI) have decreased activity and/or coherence in delta, theta, alpha and beta cognitive responses. In the current study, we investigated gamma responses in visual SEO and ERO in 15 patients with AD and in 15 age-, gender- and education-matched healthy controls. The following parameters were analyzed over the parietal-occipital regions in both groups: (i) latency of the maximum gamma response over a 0–800 ms time window; (ii) the maximum peak-to-peak amplitudes for each participant's averaged SEO and ERO gamma responses in 3 frequency ranges (25–30, 30–35, 40–48 Hz); and (iii) the maximum peak-to-peak amplitudes for each participant's averaged SEO and ERO gamma responses over a 0–800 ms time block containing four divided time windows (0–200, 200–400, 400–600, and 600–800 ms). There were main group effects in terms of both latency and peak-to-peak amplitudes of gamma ERO. However, peak-to-peak gamma ERO amplitude differences became noticeable only when the time block was divided into four time windows. SEO amplitudes in the 25–30 Hz frequency range of the 0–200 ms time window over the left hemisphere were greater in the healthy controls than in those with AD. Gamma target ERO latency was delayed up to 138 ms in AD patients when compared to healthy controls. This finding may be an effect of lagged neural signaling in cognitive circuits, which is reflected by the delayed gamma responses in those with AD. Based on the results of this study, we propose that gamma responses should be examined in a more detailed fashion using multiple frequency and time windows. PMID:26937378

Therapeutic time window and underlying therapeutic mechanism of breviscapine injection against cerebral ischemia/reperfusion injury in rats.

PubMed

Guo, Chao; Zhu, Yanrong; Weng, Yan; Wang, Shiquan; Guan, Yue; Wei, Guo; Yin, Ying; Xi, Miaomaio; Wen, Aidong

2014-01-01

Breviscapine injection is a Chinese herbal medicine standardized product extracted from Erigeron breviscapus (Vant.) Hand.-Mazz. It has been widely used for treating cardiovascular and cerebrovascular diseases. However, the therapeutic time window and the action mechanism of breviscapine are still unclear. The present study was designed to investigate the therapeutic time window and underlying therapeutic mechanism of breviscapine injection against cerebral ischemic/reperfusion injury. Sprague-Dawley rats were subjected to middle cerebral artery occlusion for 2h followed by 24h of reperfusion. Experiment part 1 was used to investigate the therapeutic time window of breviscapine. Rats were injected intravenously with 50mg/kg breviscapine at different time-points of reperfusion. After 24h of reperfusion, neurologic score, infarct volume, brain water content and serum level of neuron specific enolase (NSE) were measured in a masked fashion. Part 2 was used to explore the therapeutic mechanism of breviscapine. 4-Hydroxy-2-nonenal (4-HNE), 8-hydroxyl-2'- deoxyguanosine (8-OHdG) and the antioxidant capacity of ischemia cortex were measured by ELISA and ferric-reducing antioxidant power (FRAP) assay, respectively. Immunofluorescence and western blot analysis were used to analyze the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). Part 1: breviscapine injection significantly ameliorated neurologic deficit, reduced infarct volume and water content, and suppressed the levels of NSE in a time-dependent manner. Part 2: breviscapine inhibited the increased levels of 4-HNE and 8-OHdG, and enhanced the antioxidant capacity of cortex tissue. Moreover, breviscapine obviously raised the expression of Nrf2 and HO-1 proteins after 24h of reperfusion. The therapeutic time window of breviscapine injection for cerebral ischemia/reperfusion injury seemed to be within 5h after reperfusion. By up-regulating the expression of Nrf2/HO-1 pathway might be involved in the therapeutic mechanism of breviscapine injection. © 2013 Elsevier Ireland Ltd. All rights reserved.

Dynamic Aberration Correction for Conformal Window of High-Speed Aircraft Using Optimized Model-Based Wavefront Sensorless Adaptive Optics.

PubMed

Dong, Bing; Li, Yan; Han, Xin-Li; Hu, Bin

2016-09-02

For high-speed aircraft, a conformal window is used to optimize the aerodynamic performance. However, the local shape of the conformal window leads to large amounts of dynamic aberrations varying with look angle. In this paper, deformable mirror (DM) and model-based wavefront sensorless adaptive optics (WSLAO) are used for dynamic aberration correction of an infrared remote sensor equipped with a conformal window and scanning mirror. In model-based WSLAO, aberration is captured using Lukosz mode, and we use the low spatial frequency content of the image spectral density as the metric function. Simulations show that aberrations induced by the conformal window are dominated by some low-order Lukosz modes. To optimize the dynamic correction, we can only correct dominant Lukosz modes and the image size can be minimized to reduce the time required to compute the metric function. In our experiment, a 37-channel DM is used to mimic the dynamic aberration of conformal window with scanning rate of 10 degrees per second. A 52-channel DM is used for correction. For a 128 × 128 image, the mean value of image sharpness during dynamic correction is 1.436 × 10(-5) in optimized correction and is 1.427 × 10(-5) in un-optimized correction. We also demonstrated that model-based WSLAO can achieve convergence two times faster than traditional stochastic parallel gradient descent (SPGD) method.

Beyond the Time Window of Intravenous Thrombolysis: Standing by or by Stenting?

PubMed Central

Liu, Xinfeng

2012-01-01

Intravenous administration of tissue plasminogen activator within 4.5 h of symptom onset is presently the ‘golden rule’ for treating acute ischemic stroke. However, many patients miss the time window and others reject this treatment due to a long list of contraindications. Mechanical embolectomy has recently progressed as a potential alternative for treating patients beyond the time window for IV thrombolysis. In this paper, recent progress in mechanical embolectomy, angioplasty, and stenting in acute stroke is reviewed. Despite worries concerning the long-term clinical outcomes and increased risk of intracranial hemorrhage, favorable clinical outcomes may be achieved after mechanical embolectomy in carefully selected patients even 4.5 h after stroke onset. Potential steps should be prepared and attempted in these patients whose opportunity for recovery will elapse in a flash. PMID:25187761

Hardware Implementation of a Bilateral Subtraction Filter

NASA Technical Reports Server (NTRS)

Huertas, Andres; Watson, Robert; Villalpando, Carlos; Goldberg, Steven

2009-01-01

A bilateral subtraction filter has been implemented as a hardware module in the form of a field-programmable gate array (FPGA). In general, a bilateral subtraction filter is a key subsystem of a high-quality stereoscopic machine vision system that utilizes images that are large and/or dense. Bilateral subtraction filters have been implemented in software on general-purpose computers, but the processing speeds attainable in this way even on computers containing the fastest processors are insufficient for real-time applications. The present FPGA bilateral subtraction filter is intended to accelerate processing to real-time speed and to be a prototype of a link in a stereoscopic-machine- vision processing chain, now under development, that would process large and/or dense images in real time and would be implemented in an FPGA. In terms that are necessarily oversimplified for the sake of brevity, a bilateral subtraction filter is a smoothing, edge-preserving filter for suppressing low-frequency noise. The filter operation amounts to replacing the value for each pixel with a weighted average of the values of that pixel and the neighboring pixels in a predefined neighborhood or window (e.g., a 9 9 window). The filter weights depend partly on pixel values and partly on the window size. The present FPGA implementation of a bilateral subtraction filter utilizes a 9 9 window. This implementation was designed to take advantage of the ability to do many of the component computations in parallel pipelines to enable processing of image data at the rate at which they are generated. The filter can be considered to be divided into the following parts (see figure): a) An image pixel pipeline with a 9 9- pixel window generator, b) An array of processing elements; c) An adder tree; d) A smoothing-and-delaying unit; and e) A subtraction unit. After each 9 9 window is created, the affected pixel data are fed to the processing elements. Each processing element is fed the pixel value for its position in the window as well as the pixel value for the central pixel of the window. The absolute difference between these two pixel values is calculated and used as an address in a lookup table. Each processing element has a lookup table, unique for its position in the window, containing the weight coefficients for the Gaussian function for that position. The pixel value is multiplied by the weight, and the outputs of the processing element are the weight and pixel-value weight product. The products and weights are fed to the adder tree. The sum of the products and the sum of the weights are fed to the divider, which computes the sum of products the sum of weights. The output of the divider is denoted the bilateral smoothed image. The smoothing function is a simple weighted average computed over a 3 3 subwindow centered in the 9 9 window. After smoothing, the image is delayed by an additional amount of time needed to match the processing time for computing the bilateral smoothed image. The bilateral smoothed image is then subtracted from the 3 3 smoothed image to produce the final output. The prototype filter as implemented in a commercially available FPGA processes one pixel per clock cycle. Operation at a clock speed of 66 MHz has been demonstrated, and results of a static timing analysis have been interpreted as suggesting that the clock speed could be increased to as much as 100 MHz.

Frequency of open windows in motor vehicles under varying temperature conditions: a videotape survey in Central North Carolina during 2001.

PubMed

Long, Tom; Johnson, Ted; Ollison, Will

2004-07-01

Air pollution exposures in the motor vehicle cabin are significantly affected by air exchange rate, a function of vehicle speed, window position, vent status, fan speed, and air conditioning use. A pilot study conducted in Houston, Texas, during September 2000 demonstrated that useful information concerning the position of windows, sunroofs, and convertible tops as a function of temperature and vehicle speed could be obtained through the use of video recorders. To obtain similar data representing a wide range of temperature and traffic conditions, a follow-up study was conducted in and around Chapel Hill, North Carolina at five sites representing a central business district, an arterial road, a low-income commercial district, an interstate highway, and a rural road. Each site permitted an elevated view of vehicles as they proceeded through a turn, thereby exposing all windows to the stationary camcorder. A total of 32 videotaping sessions were conducted between February and October 2001, in which temperature varied from 41 degrees F to 93 degrees F and average vehicle speed varied from 21 to 77 mph. The resulting video tapes were processed to create a vehicle-specific database that included site location, date, time, vehicle type, vehicle color, vehicle age, window configuration, number of windows in each of three position categories (fully open, partially open, and closed), meteorological factors, and vehicle speed. Of the 4715 vehicles included in the database, 1905 (40.4%) were labeled as "open," indicating a window, sunroof, or convertible top was fully or partially open. Stepwise linear regression analyses indicated that "open" window status was affected by wind speed, relative humidity, vehicle speed, cloud cover, apparent temperature, day of week, time of day, vehicle type, vehicle age, vehicle color, number of windows, sunroofs, location, and air quality season. Open windows tended to occur less frequently when relative humidity was high, apparent temperature (a parameter incorporating wind chill and heat index) was below 50 degrees F, or the vehicle was relatively new. Although the effects of the identified parameters were relatively weak, they are statistically significant and should be considered by researchers attempting to model vehicle air exchange rates.

Quantification of Residual Stress from Photonic Signatures of Fused Silica

NASA Technical Reports Server (NTRS)

Cramer, K. Elliott; Hayward, Maurice; Yost, William E.

2013-01-01

A commercially available grey-field polariscope (GFP) instrument for photoelastic examination is used to assess impact damage inflicted upon the outer-most pane of Space Shuttle windows made from fused silica. A method and apparatus for calibration of the stress-optic coefficient using four-point bending is discussed. The results are validated on known material (acrylic) and are found to agree with literature values to within 6%. The calibration procedure is then applied to fused-silica specimens and the stress-optic coefficient is determined to be 2.43 +/- 0.54 x 10(exp -12)/Pa. Fused silica specimens containing impacts artificially made at NASA's Hypervelocity Impact Technology Facility (HIT-F), to simulate damage typical during space flight, are examined. The damage sites are cored from fused silica window carcasses and examined with the GFP. The calibrated GFP measurements of residual stress patterns surrounding the damage sites are presented. Keywords: Glass, fused silica, photoelasticity, residual stress

An Assembly Funnel Makes Biomolecular Complex Assembly Efficient

PubMed Central

Zenk, John; Schulman, Rebecca

2014-01-01

Like protein folding and crystallization, the self-assembly of complexes is a fundamental form of biomolecular organization. While the number of methods for creating synthetic complexes is growing rapidly, most require empirical tuning of assembly conditions and/or produce low yields. We use coarse-grained simulations of the assembly kinetics of complexes to identify generic limitations on yields that arise because of the many simultaneous interactions allowed between the components and intermediates of a complex. Efficient assembly occurs when nucleation is fast and growth pathways are few, i.e. when there is an assembly “funnel”. For typical complexes, an assembly funnel occurs in a narrow window of conditions whose location is highly complex specific. However, by redesigning the components this window can be drastically broadened, so that complexes can form quickly across many conditions. The generality of this approach suggests assembly funnel design as a foundational strategy for robust biomolecular complex synthesis. PMID:25360818

Quantification of residual stress from photonic signatures of fused silica

NASA Astrophysics Data System (ADS)

Cramer, K. Elliott; Hayward, Maurice; Yost, William T.

2014-02-01

A commercially available grey-field polariscope (GFP) instrument for photoelastic examination is used to assess impact damage inflicted upon the outer-most pane of Space Shuttle windows made from fused silica. A method and apparatus for calibration of the stress-optic coefficient using four-point bending is discussed. The results are validated on known material (acrylic) and are found to agree with literature values to within 6%. The calibration procedure is then applied to fused-silica specimens and the stress-optic coefficient is determined to be 2.43 ± 0.54 × 10-12 Pa-1. Fused silica specimens containing impacts artificially made at NASA's Hypervelocity Impact Technology Facility (HIT-F), to simulate damage typical during space flight, are examined. The damage sites are cored from fused silica window carcasses and examined with the GFP. The calibrated GFP measurements of residual stress patterns surrounding the damage sites are presented.

Automated Transmission Loss Measurement in the Structural Acoustic Loads and Transmission Facility at NASA Langley Research Center

NASA Technical Reports Server (NTRS)

Klos, J.; Brown, S. A.

2002-01-01

A technique to measure the radiated acoustic intensity and transmission loss of panels is documented in this paper. This facility has been upgraded to include a test fixture that scans the acoustic intensity radiated from a panel on the anechoic receiving room side of the transmission loss window. The acoustic intensity incident on the panel from the reverberant side of the transmission loss window is estimated from measurements made using six stationary microphones in the reverberant source room. From the measured incident and radiated intensity, the sound power transmission loss is calculated. The setup of the facility and data acquisition system are documented. A transmission loss estimate of a typical panel is shown. The measurement-to-measurement and setup-to-setup repeatability of the transmission loss estimate are assessed. Conclusions are drawn about the ability to measure changes in transmission loss due to changes in panel construction.

A view of metals through the terahertz window

NASA Astrophysics Data System (ADS)

Dodge, Steve

2006-05-01

As electrons move through a metal, interaction with their environment tends to slow them down, causing the Drude peak in the optical conductivity to become narrower. The resulting peak width is typically in the terahertz frequency range that sits between microwaves the far infrared, too fast for conventional electronics and too slow for conventional infrared spectroscopy. With femtosecond laser techniques, however, coherent, broadband terahertz radiation can now be generated and detected with exquisite sensitivity, providing a new window onto electronic interactions in metals. I will discuss the application of this technique to a variety of metallic systems, including elemental lead, the nearly magnetic oxide metal CaRuO3, and CrV alloys that span the quantum phase transition from spin-density wave to paramagnetic metal. M. A. Gilmore, S. Kamal, D. M. Broun, and J. S. Dodge, Appl. Phys. Lett. 88, 141910 (2006).

Endoscopic Modified Medial Maxillectomy for Fungal Ball of the Hypoplastic Maxillary Sinus With Bony Hypertrophy.

PubMed

Nomura, Kazuhiro; Ikushima, Hiroyuki; Ozawa, Daiki; Shimizu, Yuichi; Arakawa, Kazuya; Suzuki, Jun; Hidaka, Hiroshi; Katori, Yukio; Ohyama, Kenji

2018-05-01

Sinus fungal ball is defined as noninvasive chronic rhino-sinusitis with a clump of mold in the paranasal sinuses, typically affecting the maxillary sinus. Fairly good outcomes of endoscopic surgery have been reported where the ball is removed through the antrostomy. However, the affected sinus tends to have a smaller cavity and thicker bony walls. As such, it is often challenging to maintain a window size that is sufficient to control possible recurrence. The endoscopic modified medial maxillectomy procedure was applied to a 61-year old and a 70-year old female patient with maxillary sinus fungal ball. Using this method, we created a much larger inferior meatal antrostomy without difficulty. The window provided us with an endoscopic view of the whole sinus and complete eradication of the lesion. Endoscopic modified medial maxillectomy is useful as a surgical procedure for maxillary sinus fungal ball and should be considered for better outcomes.

Structural Color Model Based on Surface Morphology of MORPHO Butterfly Wing Scale

NASA Astrophysics Data System (ADS)

Huang, Zhongjia; Cai, Congcong; Wang, Gang; Zhang, Hui; Huttula, Marko; Cao, Wei

2016-05-01

Color production through structural coloration is created by micrometer and sub-micrometer surface textures which interfere with visible light. The shiny blue of morpho menelaus is a typical example of structural coloring. Modified from morphology of the morpho scale, a structure of regular windows with two side offsets was constructed on glass substrates. Optical properties of the bioinspired structure were studied through numerical simulations of light scattering. Results show that the structure can generate monochromatic light scattering. Wavelength of scattered light is tunable via changing the spacing between window shelves. Compared to original butterfly model, the modified one possesses larger illumination scopes in azimuthal distributions despite being less in polar directions. Present bionic structure is periodically repeated and is easy to fabricate. It is hoped that the computational materials design work can inspire future experimental realizations of such a structure in photonics applications.

Activity Recognition on Streaming Sensor Data.

PubMed

Krishnan, Narayanan C; Cook, Diane J

2014-02-01

Many real-world applications that focus on addressing needs of a human, require information about the activities being performed by the human in real-time. While advances in pervasive computing have lead to the development of wireless and non-intrusive sensors that can capture the necessary activity information, current activity recognition approaches have so far experimented on either a scripted or pre-segmented sequence of sensor events related to activities. In this paper we propose and evaluate a sliding window based approach to perform activity recognition in an on line or streaming fashion; recognizing activities as and when new sensor events are recorded. To account for the fact that different activities can be best characterized by different window lengths of sensor events, we incorporate the time decay and mutual information based weighting of sensor events within a window. Additional contextual information in the form of the previous activity and the activity of the previous window is also appended to the feature describing a sensor window. The experiments conducted to evaluate these techniques on real-world smart home datasets suggests that combining mutual information based weighting of sensor events and adding past contextual information into the feature leads to best performance for streaming activity recognition.

WINCADRE INORGANIC (WINDOWS COMPUTER-AIDED DATA REVIEW AND EVALUATION)

EPA Science Inventory

WinCADRE (Computer-Aided Data Review and Evaluation) is a Windows -based program designed for computer-assisted data validation. WinCADRE is a powerful tool which significantly decreases data validation turnaround time. The electronic-data-deliverable format has been designed in...

14 CFR 1214.117 - Launch and orbit parameters for a standard launch.

Code of Federal Regulations, 2010 CFR

2010-01-01

...) Launch at a time, selected by NASA, from a launch window of not less than 1 hour (a more restrictive launch window may be provided as an optional service). (b) For shared flights from KSC to the standard...

Neurodynamics of executive control processes in bilinguals: evidence from ERP and source reconstruction analyses.

PubMed

Heidlmayr, Karin; Hemforth, Barbara; Moutier, Sylvain; Isel, Frédéric

2015-01-01

The present study was designed to examine the impact of bilingualism on the neuronal activity in different executive control processes namely conflict monitoring, control implementation (i.e., interference suppression and conflict resolution) and overcoming of inhibition. Twenty-two highly proficient but non-balanced successive French-German bilingual adults and 22 monolingual adults performed a combined Stroop/Negative priming task while event-related potential (ERP) were recorded online. The data revealed that the ERP effects were reduced in bilinguals in comparison to monolinguals but only in the Stroop task and limited to the N400 and the sustained fronto-central negative-going potential time windows. This result suggests that bilingualism may impact the process of control implementation rather than the process of conflict monitoring (N200). Critically, our study revealed a differential time course of the involvement of the anterior cingulate cortex (ACC) and the prefrontal cortex (PFC) in conflict processing. While the ACC showed major activation in the early time windows (N200 and N400) but not in the latest time window (late sustained negative-going potential), the PFC became unilaterally active in the left hemisphere in the N400 and the late sustained negative-going potential time windows. Taken together, the present electroencephalography data lend support to a cascading neurophysiological model of executive control processes, in which ACC and PFC may play a determining role.

Neurodynamics of executive control processes in bilinguals: evidence from ERP and source reconstruction analyses

PubMed Central

Heidlmayr, Karin; Hemforth, Barbara; Moutier, Sylvain; Isel, Frédéric

2015-01-01

The present study was designed to examine the impact of bilingualism on the neuronal activity in different executive control processes namely conflict monitoring, control implementation (i.e., interference suppression and conflict resolution) and overcoming of inhibition. Twenty-two highly proficient but non-balanced successive French–German bilingual adults and 22 monolingual adults performed a combined Stroop/Negative priming task while event-related potential (ERP) were recorded online. The data revealed that the ERP effects were reduced in bilinguals in comparison to monolinguals but only in the Stroop task and limited to the N400 and the sustained fronto-central negative-going potential time windows. This result suggests that bilingualism may impact the process of control implementation rather than the process of conflict monitoring (N200). Critically, our study revealed a differential time course of the involvement of the anterior cingulate cortex (ACC) and the prefrontal cortex (PFC) in conflict processing. While the ACC showed major activation in the early time windows (N200 and N400) but not in the latest time window (late sustained negative-going potential), the PFC became unilaterally active in the left hemisphere in the N400 and the late sustained negative-going potential time windows. Taken together, the present electroencephalography data lend support to a cascading neurophysiological model of executive control processes, in which ACC and PFC may play a determining role. PMID:26124740

Robust sliding-window reconstruction for Accelerating the acquisition of MR fingerprinting.

PubMed

Cao, Xiaozhi; Liao, Congyu; Wang, Zhixing; Chen, Ying; Ye, Huihui; He, Hongjian; Zhong, Jianhui

2017-10-01

To develop a method for accelerated and robust MR fingerprinting (MRF) with improved image reconstruction and parameter matching processes. A sliding-window (SW) strategy was applied to MRF, in which signal and dictionary matching was conducted between fingerprints consisting of mixed-contrast image series reconstructed from consecutive data frames segmented by a sliding window, and a precalculated mixed-contrast dictionary. The effectiveness and performance of this new method, dubbed SW-MRF, was evaluated in both phantom and in vivo. Error quantifications were conducted on results obtained with various settings of SW reconstruction parameters. Compared with the original MRF strategy, the results of both phantom and in vivo experiments demonstrate that the proposed SW-MRF strategy either provided similar accuracy with reduced acquisition time, or improved accuracy with equal acquisition time. Parametric maps of T 1 , T 2 , and proton density of comparable quality could be achieved with a two-fold or more reduction in acquisition time. The effect of sliding-window width on dictionary sensitivity was also estimated. The novel SW-MRF recovers high quality image frames from highly undersampled MRF data, which enables more robust dictionary matching with reduced numbers of data frames. This time efficiency may facilitate MRF applications in time-critical clinical settings. Magn Reson Med 78:1579-1588, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Towards component-based validation of GATE: aspects of the coincidence processor.

PubMed

Moraes, Eder R; Poon, Jonathan K; Balakrishnan, Karthikayan; Wang, Wenli; Badawi, Ramsey D

2015-02-01

GATE is public domain software widely used for Monte Carlo simulation in emission tomography. Validations of GATE have primarily been performed on a whole-system basis, leaving the possibility that errors in one sub-system may be offset by errors in others. We assess the accuracy of the GATE PET coincidence generation sub-system in isolation, focusing on the options most closely modeling the majority of commercially available scanners. Independent coincidence generators were coded by teams at Toshiba Medical Research Unit (TMRU) and UC Davis. A model similar to the Siemens mCT scanner was created in GATE. Annihilation photons interacting with the detectors were recorded. Coincidences were generated using GATE, TMRU and UC Davis code and results compared to "ground truth" obtained from the history of the photon interactions. GATE was tested twice, once with every qualified single event opening a time window and initiating a coincidence check (the "multiple window method"), and once where a time window is opened and a coincidence check initiated only by the first single event to occur after the end of the prior time window (the "single window method"). True, scattered and random coincidences were compared. Noise equivalent count rates were also computed and compared. The TMRU and UC Davis coincidence generators agree well with ground truth. With GATE, reasonable accuracy can be obtained if the single window method option is chosen and random coincidences are estimated without use of the delayed coincidence option. However in this GATE version, other parameter combinations can result in significant errors. Copyright © 2014 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Exploring the relationship between cortical GABA concentrations, auditory gamma-band responses and development in ASD: Evidence for an altered maturational trajectory in ASD.

PubMed

Port, Russell G; Gaetz, William; Bloy, Luke; Wang, Dah-Jyuu; Blaskey, Lisa; Kuschner, Emily S; Levy, Susan E; Brodkin, Edward S; Roberts, Timothy P L

2017-04-01

Autism spectrum disorder (ASD) is hypothesized to arise from imbalances between excitatory and inhibitory neurotransmission (E/I imbalance). Studies have demonstrated E/I imbalance in individuals with ASD and also corresponding rodent models. One neural process thought to be reliant on E/I balance is gamma-band activity (Gamma), with support arising from observed correlations between motor, as well as visual, Gamma and underlying GABA concentrations in healthy adults. Additionally, decreased Gamma has been observed in ASD individuals and relevant animal models, though the direct relationship between Gamma and GABA concentrations in ASD remains unexplored. This study combined magnetoencephalography (MEG) and edited magnetic resonance spectroscopy (MRS) in 27 typically developing individuals (TD) and 30 individuals with ASD. Auditory cortex localized phase-locked Gamma was compared to resting Superior Temporal Gyrus relative cortical GABA concentrations for both children/adolescents and adults. Children/adolescents with ASD exhibited significantly decreased GABA+/Creatine (Cr) levels, though typical Gamma. Additionally, these children/adolescents lacked the typical maturation of GABA+/Cr concentrations and gamma-band coherence. Furthermore, children/adolescents with ASD additionally failed to exhibit the typical GABA+/Cr to gamma-band coherence association. This altered coupling during childhood/adolescence may result in Gamma decreases observed in the adults with ASD. Therefore, individuals with ASD exhibit improper local neuronal circuitry maturation during a childhood/adolescence critical period, when GABA is involved in configuring of such circuit functioning. Provocatively a novel line of treatment is suggested (with a critical time window); by increasing neural GABA levels in children/adolescents with ASD, proper local circuitry maturation may be restored resulting in typical Gamma in adulthood. Autism Res 2017, 10: 593-607. © 2016 International Society for Autism Research, Wiley Periodicals, Inc. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

Adaptive Window Zero-Crossing-Based Instantaneous Frequency Estimation

NASA Astrophysics Data System (ADS)

Sekhar, S. Chandra; Sreenivas, TV

2004-12-01

We address the problem of estimating instantaneous frequency (IF) of a real-valued constant amplitude time-varying sinusoid. Estimation of polynomial IF is formulated using the zero-crossings of the signal. We propose an algorithm to estimate nonpolynomial IF by local approximation using a low-order polynomial, over a short segment of the signal. This involves the choice of window length to minimize the mean square error (MSE). The optimal window length found by directly minimizing the MSE is a function of the higher-order derivatives of the IF which are not available a priori. However, an optimum solution is formulated using an adaptive window technique based on the concept of intersection of confidence intervals. The adaptive algorithm enables minimum MSE-IF (MMSE-IF) estimation without requiring a priori information about the IF. Simulation results show that the adaptive window zero-crossing-based IF estimation method is superior to fixed window methods and is also better than adaptive spectrogram and adaptive Wigner-Ville distribution (WVD)-based IF estimators for different signal-to-noise ratio (SNR).

Temperature rise and Heat build up inside a parked Car

NASA Astrophysics Data System (ADS)

Coady, Rose; Maheswaranathan, Ponn

2001-11-01

We have studied the heat build up inside a parked car under the hot summer Sun. Inside and outside temperatures were monitored every ten seconds from 9 AM to about 4 PM for a 2000 Toyota Camry parked in a Winthrop University parking lot without any shades or trees. Two PASCO temperature sensors, one inside the car and the other outside the car, are used along with PASCO-750 interface to collect the data. Data were collected under the following conditions while keeping track of the outside weather: fully closed windows, slightly open windows, half way open windows, fully open windows, and with window shades inside and outside. Inside temperatures reached as high as 150 degrees Fahrenheit on a sunny day with outside high temperature of about 100 degrees Fahrenheit. These results will be presented along with results from car cover and window tint manufacturers and suggestions to keep your car cool next time you park it under the Sun.

aCLIMAX 4.0.1, The new version of the software for analyzing and interpreting INS spectra

NASA Astrophysics Data System (ADS)

Ramirez-Cuesta, A. J.

2004-03-01

In Inelastic Neutron Scattering Spectroscopy, the neutron scattering intensity is plotted versus neutron energy loss giving a spectrum that looks like an infrared or a Raman spectrum. Unlike IR or Raman, INS does not have selection rules, i.e. all transitions are in principle observable. This particular characteristic makes INS a test bed for Density Functional Theory calculations of vibrational modes. aCLIMAX is the first user friendly program, within the Windows environment, that uses the output of normal modes to generate the calculated INS of the model molecule, making a lot easier to establish a connection between theory and experiment. Program summaryTitle of program: aCLIMAX 4.0.1 Catalogue identifier: ADSW Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADSW Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Operating systems: Windows 95 onwards, except Windows ME where it does not work Programming language used: Visual Basic Memory requirements: 64 MB No. of processors: 1 Has the code been parallelized: No No. of bytes in distributed program, including test data, etc.: 2 432 775 No. of lines in distributed program, including test data, etc.: 17 998 Distribution format: tar gzip file Nature of physical problem: Calculation of the Inelastic Neutron Scattering Spectra from DFT calculations of the vibrational density of states for molecules. Method of solution: INS spectral intensity calculated from normal modes analysis. Isolated molecule approximation. Typical time of running: From few seconds to few minutes depending on the size of the molecule. Unusual features of the program: Special care has to be taken in the case of computers that have different regional options than the English speaking countries, the decimal separator has to be set as "." (dot) instead of the usual "," (comma) that most countries use.

Adaptive synchrosqueezing based on a quilted short-time Fourier transform

NASA Astrophysics Data System (ADS)

Berrian, Alexander; Saito, Naoki

2017-08-01

In recent years, the synchrosqueezing transform (SST) has gained popularity as a method for the analysis of signals that can be broken down into multiple components determined by instantaneous amplitudes and phases. One such version of SST, based on the short-time Fourier transform (STFT), enables the sharpening of instantaneous frequency (IF) information derived from the STFT, as well as the separation of amplitude-phase components corresponding to distinct IF curves. However, this SST is limited by the time-frequency resolution of the underlying window function, and may not resolve signals exhibiting diverse time-frequency behaviors with sufficient accuracy. In this work, we develop a framework for an SST based on a "quilted" short-time Fourier transform (SST-QSTFT), which allows adaptation to signal behavior in separate time-frequency regions through the use of multiple windows. This motivates us to introduce a discrete reassignment frequency formula based on a finite difference of the phase spectrum, ensuring computational accuracy for a wider variety of windows. We develop a theoretical framework for the SST-QSTFT in both the continuous and the discrete settings, and describe an algorithm for the automatic selection of optimal windows depending on the region of interest. Using synthetic data, we demonstrate the superior numerical performance of SST-QSTFT relative to other SST methods in a noisy context. Finally, we apply SST-QSTFT to audio recordings of animal calls to demonstrate the potential of our method for the analysis of real bioacoustic signals.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ojeda-Gonzalez, A.; Prestes, A.; Klausner, V.

Spatio-temporal entropy (STE) analysis is used as an alternative mathematical tool to identify possible magnetic cloud (MC) candidates. We analyze Interplanetary Magnetic Field (IMF) data using a time interval of only 10 days. We select a convenient data interval of 2500 records moving forward by 200 record steps until the end of the time series. For every data segment, the STE is calculated at each step. During an MC event, the STE reaches values close to zero. This extremely low value of STE is due to MC structure features. However, not all of the magnetic components in MCs have STEmore » values close to zero at the same time. For this reason, we create a standardization index (the so-called Interplanetary Entropy, IE, index). This index is a worthwhile effort to develop new tools to help diagnose ICME structures. The IE was calculated using a time window of one year (1999), and it has a success rate of 70% over other identifiers of MCs. The unsuccessful cases (30%) are caused by small and weak MCs. The results show that the IE methodology identified 9 of 13 MCs, and emitted nine false alarm cases. In 1999, a total of 788 windows of 2500 values existed, meaning that the percentage of false alarms was 1.14%, which can be considered a good result. In addition, four time windows, each of 10 days, are studied, where the IE method was effective in finding MC candidates. As a novel result, two new MCs are identified in these time windows.« less

Deep Recurrent Neural Networks for Human Activity Recognition

PubMed Central

Murad, Abdulmajid

2017-01-01

Adopting deep learning methods for human activity recognition has been effective in extracting discriminative features from raw input sequences acquired from body-worn sensors. Although human movements are encoded in a sequence of successive samples in time, typical machine learning methods perform recognition tasks without exploiting the temporal correlations between input data samples. Convolutional neural networks (CNNs) address this issue by using convolutions across a one-dimensional temporal sequence to capture dependencies among input data. However, the size of convolutional kernels restricts the captured range of dependencies between data samples. As a result, typical models are unadaptable to a wide range of activity-recognition configurations and require fixed-length input windows. In this paper, we propose the use of deep recurrent neural networks (DRNNs) for building recognition models that are capable of capturing long-range dependencies in variable-length input sequences. We present unidirectional, bidirectional, and cascaded architectures based on long short-term memory (LSTM) DRNNs and evaluate their effectiveness on miscellaneous benchmark datasets. Experimental results show that our proposed models outperform methods employing conventional machine learning, such as support vector machine (SVM) and k-nearest neighbors (KNN). Additionally, the proposed models yield better performance than other deep learning techniques, such as deep believe networks (DBNs) and CNNs. PMID:29113103

Deep Recurrent Neural Networks for Human Activity Recognition.

PubMed

Murad, Abdulmajid; Pyun, Jae-Young

2017-11-06

Adopting deep learning methods for human activity recognition has been effective in extracting discriminative features from raw input sequences acquired from body-worn sensors. Although human movements are encoded in a sequence of successive samples in time, typical machine learning methods perform recognition tasks without exploiting the temporal correlations between input data samples. Convolutional neural networks (CNNs) address this issue by using convolutions across a one-dimensional temporal sequence to capture dependencies among input data. However, the size of convolutional kernels restricts the captured range of dependencies between data samples. As a result, typical models are unadaptable to a wide range of activity-recognition configurations and require fixed-length input windows. In this paper, we propose the use of deep recurrent neural networks (DRNNs) for building recognition models that are capable of capturing long-range dependencies in variable-length input sequences. We present unidirectional, bidirectional, and cascaded architectures based on long short-term memory (LSTM) DRNNs and evaluate their effectiveness on miscellaneous benchmark datasets. Experimental results show that our proposed models outperform methods employing conventional machine learning, such as support vector machine (SVM) and k-nearest neighbors (KNN). Additionally, the proposed models yield better performance than other deep learning techniques, such as deep believe networks (DBNs) and CNNs.

DASCH to Measure (and preserve) the Harvard Plates: Opening the ˜100-year Time Domain Astronomy Window

NASA Astrophysics Data System (ADS)

Grindlay, J.; Tang, S.; Simcoe, R.; Laycock, S.; Los, E.; Mink, D.; Doane, A.; Champine, G.

2009-08-01

The temporal Universe is now possible to study on previously inaccessible timescales of days to decades, over a full century, with the planned full-digitization of the Harvard plate collection. The Digital Access to a Sky Century @ Harvard (DASCH) project has developed the world's highest-speed precision plate scanner and the required software to digitize the ˜500,000 glass photographic plates (mostly 20 x 25~cm) that record images of the full sky taken by some 20 telescopes in both hemispheres over the period 1880 - 1985. These provide ˜500-1000 measures of any object brighter than the plate limit (typically B ˜14 - 17) with photometric accuracy from the digital image typically Δm ˜0.10 - 0.15 mag, with the presently developed photometry pipeline and spatially-dependent calibration (using the Hubble Guide Star Catalog) for each plate. We provide an overview of DASCH, the processing, and example light curves that illustrate the power of this unique dataset and resource. Production scanning and serving on-line the entire ˜1 PB database (both images and derived light curves) on spinning disk could be completed within ˜3 - 5 y after funding (for scanner operations and database construction) is obtained.

Changes in seasonal streamflow extremes experienced in rivers of Northwestern South America (Colombia)

NASA Astrophysics Data System (ADS)

Pierini, J. O.; Restrepo, J. C.; Aguirre, J.; Bustamante, A. M.; Velásquez, G. J.

2017-04-01

A measure of the variability in seasonal extreme streamflow was estimated for the Colombian Caribbean coast, using monthly time series of freshwater discharge from ten watersheds. The aim was to detect modifications in the streamflow monthly distribution, seasonal trends, variance and extreme monthly values. A 20-year length time moving window, with 1-year successive shiftments, was applied to the monthly series to analyze the seasonal variability of streamflow. The seasonal-windowed data were statistically fitted through the Gamma distribution function. Scale and shape parameters were computed using the Maximum Likelihood Estimation (MLE) and the bootstrap method for 1000 resample. A trend analysis was performed for each windowed-serie, allowing to detect the window of maximum absolute values for trends. Significant temporal shifts in seasonal streamflow distribution and quantiles (QT), were obtained for different frequencies. Wet and dry extremes periods increased significantly in the last decades. Such increase did not occur simultaneously through the region. Some locations exhibited continuous increases only at minimum QT.

Ambulatory Blood Pressure Monitoring in Clinical Practice: A Review

PubMed Central

Viera, Anthony J.; Shimbo, Daichi

2016-01-01

Ambulatory blood pressure monitoring offers the ability to collect blood pressure readings several times an hour across a 24-hour period. Ambulatory blood pressure monitoring facilitates the identification of white-coat hypertension, the phenomenon whereby certain individuals who are not on antihypertensive medication show elevated blood pressure in a clinical setting but show non-elevated blood pressure averages when assessed by ambulatory blood pressure monitoring. Additionally, readings can be segmented into time windows of particular interest, e.g., mean daytime and nighttime values. During sleep, blood pressure typically decreases, or dips, such that mean sleep blood pressure is lower than mean awake blood pressure. A non-dipping pattern and nocturnal hypertension are strongly associated with increased cardiovascular morbidity and mortality. Approximately 70% of individuals dip ≥10% at night, while 30% have non-dipping patterns, when blood pressure remains similar to daytime average, or occasionally rises above daytime average. The various blood pressure categorizations afforded by ambulatory blood pressure monitoring are valuable for clinical management of high blood pressure since they increase accuracy for diagnosis and the prediction of cardiovascular risk. PMID:25107387

Transformation of Context-dependent Sensory Dynamics into Motor Behavior

PubMed Central

Latorre, Roberto; Levi, Rafael; Varona, Pablo

2013-01-01

The intrinsic dynamics of sensory networks play an important role in the sensory-motor transformation. In this paper we use conductance based models and electrophysiological recordings to address the study of the dual role of a sensory network to organize two behavioral context-dependent motor programs in the mollusk Clione limacina. We show that: (i) a winner take-all dynamics in the gravimetric sensory network model drives the typical repetitive rhythm in the wing central pattern generator (CPG) during routine swimming; (ii) the winnerless competition dynamics of the same sensory network organizes the irregular pattern observed in the wing CPG during hunting behavior. Our model also shows that although the timing of the activity is irregular, the sequence of the switching among the sensory cells is preserved whenever the same set of neurons are activated in a given time window. These activation phase locks in the sensory signals are transformed into specific events in the motor activity. The activation phase locks can play an important role in motor coordination driven by the intrinsic dynamics of a multifunctional sensory organ. PMID:23459114

Planning steps forward in development: in girls earlier than in boys.

PubMed

Unterrainer, Josef M; Ruh, Nina; Loosli, Sandra V; Heinze, Katharina; Rahm, Benjamin; Kaller, Christoph P

2013-01-01

The development of planning ability in children initially aged four and five was examined longitudinally with a retest-interval of 12 months using the Tower of London task. As expected, problems to solve straightforward without mental look-ahead were mastered by most, even the youngest children. Problems demanding look-ahead were more difficult and accuracy improved significantly with age and over time. This development was strongly moderated by sex: In contrast to coeval boys, four year old girls showed an impressive performance enhancement at age five, reaching the performance of six year olds, whereas four year old boys lagged behind and caught up with girls at the age of six, the typical age of school enrollment. This sex-specific development of planning was clearly separated from overall intelligence: young boys showed a steeper increase in raw intelligence scores than girls, whereas in the older groups scores developed similarly. The observed sex differences in planning development are evident even within a narrow time window of twelve months and may relate to differences in maturational trajectories for girls and boys in dorsolateral prefrontal cortex.

Spatial attention does improve temporal discrimination.

PubMed

Chica, Ana B; Christie, John

2009-02-01

It has recently been stated that exogenous attention impairs temporal-resolution tasks (Hein, Rolke, & Ulrich, 2006; Rolke, Dinkelbach, Hein, & Ulrich, 2008; Yeshurun, 2004; Yeshurun & Levy, 2003). In comparisons of performance on spatially cued trials versus neutral cued trials, the results have suggested that spatial attention decreases temporal resolution. However, when performance on cued and uncued trials has been compared in order to equate for cue salience, typically speed-accuracy trade-offs (SATs) have been observed, making the interpretation of the results difficult. In the present experiments, we aimed at studying the effect of spatial attention in temporal resolution while using a procedure to control for SATs. We controlled reaction times (RTs) by constraining the time to respond, so that response decisions would be made within comparable time windows. The results revealed that when RT was controlled, performance was impaired for cued trials as compared with neutral trials, replicating previous findings. However, when cued and uncued trials were compared, performance was actually improved for cued trials as compared with uncued trials. These results suggest that SAT effects may have played an important role in the previous studies, because when they were controlled and measured, the results reversed, revealing that exogenous attention does improve performance on temporal-resolution tasks.

SNS Proton Beam Window Disposal

NASA Astrophysics Data System (ADS)

Popova, Irina; Gallmeier, Franz X.; Trotter, Steven

2017-09-01

In order to support the disposal of the proton beam window assembly of the Spallation Neutron Source beamline to the target station, waste classification analyses are performed. The window has a limited life-time due to radiation-induced material damage. Analyses include calculation of the radionuclide inventory and shielding analyses for the transport package/container to ensure that the container is compliant with the transportation and waste management regulations. In order to automate this procedure and minimize manual work a script in Perl language was written.

Identification of Scattering Mechanisms from Measured Impulse Response Signatures of Several Conducting Objects.

DTIC Science & Technology

1984-02-01

conducting sphere 35 compared to inverse transform of exact solution. 4-5. Measured impulse response of a conducting 2:1 right 37 circular cylinder with...frequency domain. This is equivalent to multiplication in the time domain by the inverse transform of w(n), which is shown in Figure 3-1 for N=15. The...equivalent pulse width from 0.066 T for the rectangular window to 0.10 T for the Hanning window. The inverse transform of the Hanning window is shown

Removal of Noise from a Voice Signal by Synthesis

DTIC Science & Technology

1973-05-01

for 102.4 millisecond windows is about five times as great as the cost of computing for 25.6 millisecond windows. Hammett in his work on an adaptive...spectrum analysis vocoder, has examined the selection of data window widths in detail [18]. The solution Hammett used to optimize the trade off between...result is: n s(t) E Ri(t - i . T) i-1 In this equation n is the number of impulse responses under consideration, s(t) is the resulting synthetic signal

Real-time 3-D contrast-enhanced transcranial ultrasound and aberration correction.

PubMed

Ivancevich, Nikolas M; Pinton, Gianmarco F; Nicoletto, Heather A; Bennett, Ellen; Laskowitz, Daniel T; Smith, Stephen W

2008-09-01

Contrast-enhanced (CE) transcranial ultrasound (US) and reconstructed 3-D transcranial ultrasound have shown advantages over traditional methods in a variety of cerebrovascular diseases. We present the results from a novel ultrasound technique, namely real-time 3-D contrast-enhanced transcranial ultrasound. Using real-time 3-D (RT3D) ultrasound and microbubble contrast agent, we scanned 17 healthy volunteers via a single temporal window and nine via the suboccipital window and report our detection rates for the major cerebral vessels. In 71% of subjects, both of our observers identified the ipsilateral circle of Willis from the temporal window, and in 59% we imaged the entire circle of Willis. From the suboccipital window, both observers detected the entire vertebrobasilar circulation in 22% of subjects, and in 44%, the basilar artery. After performing phase aberration correction on one subject, we were able to increase the diagnostic value of the scan, detecting a vessel not present in the uncorrected scan. These preliminary results suggest that RT3D CE transcranial US and RT3D CE transcranial US with phase aberration correction have the potential to greatly impact the field of neurosonology.

Real-Time 3D Contrast-Enhanced Transcranial Ultrasound and Aberration Correction

PubMed Central

Ivancevich, Nikolas M.; Pinton, Gianmarco F.; Nicoletto, Heather A.; Bennett, Ellen; Laskowitz, Daniel T.; Smith, Stephen W.

2008-01-01

Contrast-enhanced (CE) transcranial ultrasound (US) and reconstructed 3D transcranial ultrasound have shown advantages over traditional methods in a variety of cerebrovascular diseases. We present the results from a novel ultrasound technique, namely real-time 3D contrast-enhanced transcranial ultrasound. Using real-time 3D (RT3D) ultrasound and micro-bubble contrast agent, we scanned 17 healthy volunteers via a single temporal window and 9 via the sub-occipital window and report our detection rates for the major cerebral vessels. In 71% of subjects, both of our observers identified the ipsilateral circle of Willis from the temporal window, and in 59% we imaged the entire circle of Willis. From the sub-occipital window, both observers detected the entire vertebrobasilar circulation in 22% of subjects, and in 44% the basilar artery. After performing phase aberration correction on one subject, we were able to increase the diagnostic value of the scan, detecting a vessel not present in the uncorrected scan. These preliminary results suggest that RT3D CE transcranial US and RT3D CE transcranial US with phase aberration correction have the potential to greatly impact the field of neurosonology. PMID:18395321

Phenology-based, remote sensing of post-burn disturbance windows in rangelands

USGS Publications Warehouse

Sankeya, Joel B.; Wallace, Cynthia S.A.; Ravi, Sujith

2013-01-01

Wildland fire activity has increased in many parts of the world in recent decades. Ecological disturbance by fire can accelerate ecosystem degradation processes such as erosion due to combustion of vegetation that otherwise provides protective cover to the soil surface. This study employed a novel ecological indicator based on remote sensing of vegetation greenness dynamics (phenology) to estimate variability in the window of time between fire and the reemergence of green vegetation. The indicator was applied as a proxy for short-term, post-fire disturbance windows in rangelands; where a disturbance window is defined as the time required for an ecological or geomorphic process that is altered to return to pre-disturbance levels. We examined variability in the indicator determined for time series of MODIS and AVHRR NDVI remote sensing data for a database of ∼100 historical wildland fires, with associated post-fire reseeding treatments, that burned 1990–2003 in cold desert shrub steppe of the Great Basin and Columbia Plateau of the western USA. The indicator-based estimates of disturbance window length were examined relative to the day of the year that fires burned and seeding treatments to consider effects of contemporary variability in fire regime and management activities in this environment. A key finding was that contemporary changes of increased length of the annual fire season could have indirect effects on ecosystem degradation, as early season fires appeared to result in longer time that soils remained relatively bare of the protective cover of vegetation after fires. Also important was that reemergence of vegetation did not occur more quickly after fire in sites treated with post-fire seeding, which is a strategy commonly employed to accelerate post-fire vegetation recovery and stabilize soil. Future work with the indicator could examine other ecological factors that are dynamic in space and time following disturbance – such as nutrient cycling, carbon storage, microbial community composition, or soil hydrology – as a function of disturbance windows, possibly using simulation modeling and historical wildfire information.

Time and timing in the acoustic recognition system of crickets

PubMed Central

Hennig, R. Matthias; Heller, Klaus-Gerhard; Clemens, Jan

2014-01-01

The songs of many insects exhibit precise timing as the result of repetitive and stereotyped subunits on several time scales. As these signals encode the identity of a species, time and timing are important for the recognition system that analyzes these signals. Crickets are a prominent example as their songs are built from sound pulses that are broadcast in a long trill or as a chirped song. This pattern appears to be analyzed on two timescales, short and long. Recent evidence suggests that song recognition in crickets relies on two computations with respect to time; a short linear-nonlinear (LN) model that operates as a filter for pulse rate and a longer integration time window for monitoring song energy over time. Therefore, there is a twofold role for timing. A filter for pulse rate shows differentiating properties for which the specific timing of excitation and inhibition is important. For an integrator, however, the duration of the time window is more important than the precise timing of events. Here, we first review evidence for the role of LN-models and integration time windows for song recognition in crickets. We then parameterize the filter part by Gabor functions and explore the effects of duration, frequency, phase, and offset as these will correspond to differently timed patterns of excitation and inhibition. These filter properties were compared with known preference functions of crickets and katydids. In a comparative approach, the power for song discrimination by LN-models was tested with the songs of over 100 cricket species. It is demonstrated how the acoustic signals of crickets occupy a simple 2-dimensional space for song recognition that arises from timing, described by a Gabor function, and time, the integration window. Finally, we discuss the evolution of recognition systems in insects based on simple sensory computations. PMID:25161622

Exterior building details of Building B, east façade: embedded wood ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Exterior building details of Building B, east façade: embedded wood beams and interrupted dentil course cornice resulting from the removal of the third floor tuberculosis ward, yard level paneled Dutch door, second level two a typical six-light wood casement windows over a single-panel wood door with four light exits to fire escape; westerly view - San Quentin State Prison, Building 22, Point San Quentin, San Quentin, Marin County, CA

A CMake-Based Cross Platform Build System for Tcl/Tk

DTIC Science & Technology

2011-11-01

expressing the logic for generating user-installable packages of the finished package. While specific com- pilation instructions are typically unique to each...Windows com- pilation . This presented a difficulty for the BRL- CAD project in that neither of these systems inte- grated well with BRL-CAD’s own build...build files. 2. Implement enough of the Tcl/Tk–specific com- pilation macro logic in CMake to support build- 1Twylite’s Coffee project uses CMake to

Novel Techniques for Characterizing and Understanding the Response of Rubbers and Rubber-Based Composites to Impact Loading

DTIC Science & Technology

2016-09-30

4 of 42 Figure 9. Left: Schematic representation of the gas -gun experiment and a typical speckle pattern the specimen surface, the 12...12 correlation window used in subsequent analysis is also indicated (red rectangle). Right: a photograph of the gas -gun system...20 Figure 11. Left: Averaged acceleration and strain rate and history of μ and α prediction from gas -gun experiment on an EPDM specimen

Constraint of the 13C(α,n) Cross Section Toward Astrophysical Energies for the Main s-Process

NASA Astrophysics Data System (ADS)

Toomey, Rebecca; Febbraro, Michael T.; Pain, Steven D.; Peters, William A.; Cizewski, Jolie A.; Havener, Charles C.; Bannister, Mark E.; Chipps, Kelly A.; Walter, David G.; Ummel, Chad C.; Sims, Harrison

2017-09-01

The slow neutron capture process (s-process) typically occurs in relatively low neutron flux environments, such as AGB stars, and is a key mechanism in heavy-element synthesis. The dominant source of neutrons for the main s-process is the 13C(α,n) reaction, which proceeds at stellar temperatures ( 0.1 GK, 200 keV), via reactions well below the Coulomb barrier. Direct measurements of the reaction rate in the Gamow window ( 140- 230 keV) is difficult, complicated by the low yields and high beam currents required. Current measurements have constrained the cross section down to approximately 320 keV - still well above stellar conditions- with significant statistical uncertainties. These uncertainties, and the influence of a near-threshold 1 /2+ state at 6.4 MeV, means that extrapolation of the data into the Gamow window is unreliable. These measurements typically use high-efficiency moderated neutron counter detectors, meaning energy information of the incident neutrons is lost. A quasi-spectroscopic approach has been used to measure the 13C(α,n) reaction rate at energies between 300-350 keV with the aim of reducing uncertainties in current measurements. Work supported in part by U.S. D.O.E., the National Science Foundation and the LDRD Program of ORNL, managed by UT-Battelle, LLC.

Sensitivity to Audiovisual Temporal Asynchrony in Children With a History of Specific Language Impairment and Their Peers With Typical Development: A Replication and Follow-Up Study

PubMed Central

2017-01-01

Purpose Earlier, my colleagues and I showed that children with a history of specific language impairment (H-SLI) are significantly less able to detect audiovisual asynchrony compared with children with typical development (TD; Kaganovich & Schumaker, 2014). Here, I first replicate this finding in a new group of children with H-SLI and TD and then examine a relationship among audiovisual function, attention skills, and language in a combined pool of children. Method The stimuli were a pure tone and an explosion-shaped figure. Stimulus onset asynchrony (SOA) varied from 0–500 ms. Children pressed 1 button for perceived synchrony and another for asynchrony. I measured the number of synchronous perceptions at each SOA and calculated children's temporal binding windows. I, then, conducted multiple regressions to determine if audiovisual processing and attention can predict language skills. Results As in the earlier study, children with H-SLI perceived asynchrony significantly less frequently than children with TD at SOAs of 400–500 ms. Their temporal binding windows were also larger. Temporal precision and attention predicted 23%–37% of children's language ability. Conclusions Audiovisual temporal processing is impaired in children with H-SLI. The degree of this impairment is a predictor of language skills. Once understood, the mechanisms underlying this deficit may become a new focus for language remediation. PMID:28715546

Ultra-broadband THz time-domain spectroscopy of common polymers using THz air photonics.

PubMed

D'Angelo, Francesco; Mics, Zoltán; Bonn, Mischa; Turchinovich, Dmitry

2014-05-19

Terahertz-range dielectric properties of the common polymers low-density polyethylene (LDPE), cyclic olefin/ethylene copolymer (TOPAS®), polyamide-6 (PA6), and polytetrafluoroethylene (PTFE or Teflon®) are characterized in the ultra-broadband frequency window 2-15 THz, using a THz time-domain spectrometer employing air-photonics for the generation and detection of single-cycle sub-50 fs THz transients. The time domain measurements provide direct access to both the absorption and refractive index spectra. The polymers LDPE and TOPAS® demonstrate negligible absorption and spectrally-flat refractive index across the entire spectroscopy window, revealing the high potential of these polymers for applications in THz photonics such as ultra-broadband polymer-based dielectric mirrors, waveguides, and fibers. Resonant high-frequency polar vibrational modes are observed and assigned in polymers PA6 and PTFE, and their dielectric functions in the complete frequency window 2-15 THz are theoretically reproduced. Our results demonstrate the potential of ultra-broadband air-photonics-based THz time domain spectroscopy as a valuable analytic tool for materials science.

A model linking video gaming, sleep quality, sweet drinks consumption and obesity among children and youth.

PubMed

Turel, O; Romashkin, A; Morrison, K M

2017-08-01

There is a growing need to curb paediatric obesity. The aim of this study is to untangle associations between video-game-use attributes and obesity as a first step towards identifying and examining possible interventions. Cross-sectional time-lagged cohort study was employed using parent-child surveys (t1) and objective physical activity and physiological measures (t2) from 125 children/adolescents (mean age = 13.06, 9-17-year-olds) who play video games, recruited from two clinics at a Canadian academic children's hospital. Structural equation modelling and analysis of covariance were employed for inference. The results of the study are as follows: (i) self-reported video-game play duration in the 4-h window before bedtime is related to greater abdominal adiposity (waist-to-height ratio) and this association may be mediated through reduced sleep quality (measured with the Pittsburgh Sleep Quality Index); and (ii) self-reported average video-game session duration is associated with greater abdominal adiposity and this association may be mediated through higher self-reported sweet drinks consumption while playing video games and reduced sleep quality. Video-game play duration in the 4-h window before bedtime, typical video-game session duration, sweet drinks consumption while playing video games and poor sleep quality have aversive associations with abdominal adiposity. Paediatricians and researchers should further explore how these factors can be altered through behavioural or pharmacological interventions as a means to reduce paediatric obesity. © 2017 World Obesity Federation.

The short time Fourier transform and local signals

NASA Astrophysics Data System (ADS)

Okumura, Shuhei

In this thesis, I examine the theoretical properties of the short time discrete Fourier transform (STFT). The STFT is obtained by applying the Fourier transform by a fixed-sized, moving window to input series. We move the window by one time point at a time, so we have overlapping windows. I present several theoretical properties of the STFT, applied to various types of complex-valued, univariate time series inputs, and their outputs in closed forms. In particular, just like the discrete Fourier transform, the STFT's modulus time series takes large positive values when the input is a periodic signal. One main point is that a white noise time series input results in the STFT output being a complex-valued stationary time series and we can derive the time and time-frequency dependency structure such as the cross-covariance functions. Our primary focus is the detection of local periodic signals. I present a method to detect local signals by computing the probability that the squared modulus STFT time series has consecutive large values exceeding some threshold after one exceeding observation following one observation less than the threshold. We discuss a method to reduce the computation of such probabilities by the Box-Cox transformation and the delta method, and show that it works well in comparison to the Monte Carlo simulation method.

Error analysis and new dual-cosine window for estimating the sensor frequency response function from the step response data

NASA Astrophysics Data System (ADS)

Yang, Shuang-Long; Liang, Li-Ping; Liu, Hou-De; Xu, Ke-Jun

2018-03-01

Aiming at reducing the estimation error of the sensor frequency response function (FRF) estimated by the commonly used window-based spectral estimation method, the error models of interpolation and transient errors are derived in the form of non-parameter models. Accordingly, window effects on the errors are analyzed and reveal that the commonly used hanning window leads to smaller interpolation error which can also be significantly eliminated by the cubic spline interpolation method when estimating the FRF from the step response data, and window with smaller front-end value can restrain more transient error. Thus, a new dual-cosine window with its non-zero discrete Fourier transform bins at -3, -1, 0, 1, and 3 is constructed for FRF estimation. Compared with the hanning window, the new dual-cosine window has the equivalent interpolation error suppression capability and better transient error suppression capability when estimating the FRF from the step response; specifically, it reduces the asymptotic property of the transient error from O(N-2) of the hanning window method to O(N-4) while only increases the uncertainty slightly (about 0.4 dB). Then, one direction of a wind tunnel strain gauge balance which is a high order, small damping, and non-minimum phase system is employed as the example for verifying the new dual-cosine window-based spectral estimation method. The model simulation result shows that the new dual-cosine window method is better than the hanning window method for FRF estimation, and compared with the Gans method and LPM method, it has the advantages of simple computation, less time consumption, and short data requirement; the actual data calculation result of the balance FRF is consistent to the simulation result. Thus, the new dual-cosine window is effective and practical for FRF estimation.

Video Diagnostic for W7-X Stellarator

NASA Astrophysics Data System (ADS)

Sárközi, J.; Grosser, K.; Kocsis, G.; König, R.; Neuner, U.; Molnár, Á.; Petravich, G.; Por, G.; Porempovics, G.; Récsei, S.; Szabó, V.; Szappanos, A.; Zoletnik, S.

2008-03-01

The video diagnostics for W7-X—which is under development—is devoted to observe plasma and frrst wall elements during operation, to warn in case of hot spots and dangerous heat load and to give information about the plasma size, position, edge structure, the geometry and location of magnetic islands and distribution of impurities. The video diagnostics will be mounted on the tangential AEQ-ports of the torus that are not straight and have about 2m length and a typical diameter of 0.1m which makes its realization more difficult. The geometry of the 10 tangential views of the AEQ-ports allows giving an almost complete overview of the vessel interior making this diagnostic indispensable for the machine operation. Different concepts of the diagnostics were investigated and finally the following design was selected. As a large heat load is expected on the optical window located at the plasma-facing end of the AEQ-port, the port window is protected by a cooled pinhole. An uncooled shutter located behind the pinhole can be closed to prevent window contamination during vessel conditioning discharges (glow discharge cleaning) and from inter-pulse deposition of soft a-C:H layers. The imaging optics and the detection sensor are located behind the port window in the port tube, which will be under atmospheric pressure. To detect the visible radiation distribution a new camera system called Event Detection Intelligent Camera (EDICAM) is under development. The system is divided into three major separated components. The Sensor Module contains only the selected CMOS sensor, the analog digital converters and the minimal electronics necessary for the communication with the subsequent camera system module called Image Processing and Control Unit (IPCU). Its simple structure makes the Sensor Module suitable to operate despite being exposed to ionizing (neutron, γ-) radiation. The IPCU, which can be located far from the Sensor Module and therefore far from the plasma, is designed to perform real time evaluation of the images detecting predefined events, managing the sensor read-out and the input triggers and producing the output triggers generated by the detected events. The IPCU can also be used to reduce the amount of the stored data. A Standard 10 Gigabit Ethernet fiber optics connection connects the IPCU module to the PC with GigEVision communication protocol.

Devonian volcanic rocks of the southern Chinese Altai, NW China: Petrogenesis and implication for a propagating slab-window magmatism induced by ridge subduction during accretionary orogenesis

NASA Astrophysics Data System (ADS)

Ma, Xiaomei; Cai, Keda; Zhao, Taiping; Bao, Zihe; Wang, Xiangsong; Chen, Ming; Buslov, M. M.

2018-07-01

Ridge-trench interaction is a common tectonic process of the present-day Pacific Rim accretionary orogenic belts, and this process may facilitate "slab-window" magmatism that can produce significant thermal anomalies and geochemically unusual magmatic events. However, ridge-trench interaction has rarely been well-documented in the ancient geologic record, leading to grossly underestimation of this process in tectonic syntheses of plate margins. The Chinese Altai was inferred to have undergone ridge subduction in the Devonian and a slab-window model is proposed to interpret its high-temperature metamorphism and geochemically unique magmatic rocks, which can serve as an excellent and unique place to refine the tectonic evolution associated with ridge subduction in an ancient accretionary orogeny. For this purpose, we carried out geochemical and geochronological studies on Devonian basaltic rocks in this region. Secondary ion mass spectrometry (SIMS) zircon U-Pb dating results yield an age of 376.2 ± 2.4 Ma, suggesting an eruption at the time of Late Devonian. Geochemically, the samples in this study have variable SiO2 (43.3-58.3 wt%), low K2O (0.02-0.07 wt%) and total alkaline contents (2.16-5.41 wt%), as well as Fe2O3T/MgO ratios, showing typical tholeiitic affinity. On the other hand, the basaltic rocks display MORB-like REE patterns ((La/Yb)N = 0.90-2.57) and (Ga/Yb)N = 0.97-1.28), and have moderate positive εNd(t) values (+4.4 to +5.4), which collectively suggest a derivation from a mixing source comprising MORB-like mantle of a mature back-arc basin and subordinate arc mantle wedge. These basaltic rocks are characterized by Low La/Yb (1.26-3.69), Dy/Yb (1.51-1.77) and Sm/Yb (0.83-1.32) ratios, consistent with magmas derived from low degree (∼10%) partial melting of the spinel lherzolite source at a quite shallow mantle depth. Considering the distinctive petrogenesis of the basaltic rocks in this region, the Late Devonian basalts in the southern Chinese Altai is suggested to have witnessed the propagating process of slab-window magmatism that was induced by ridge subduction in a nascent rifting stage of a back-arc basin.

Dynamic Aberration Correction for Conformal Window of High-Speed Aircraft Using Optimized Model-Based Wavefront Sensorless Adaptive Optics

PubMed Central

Dong, Bing; Li, Yan; Han, Xin-li; Hu, Bin

2016-01-01

For high-speed aircraft, a conformal window is used to optimize the aerodynamic performance. However, the local shape of the conformal window leads to large amounts of dynamic aberrations varying with look angle. In this paper, deformable mirror (DM) and model-based wavefront sensorless adaptive optics (WSLAO) are used for dynamic aberration correction of an infrared remote sensor equipped with a conformal window and scanning mirror. In model-based WSLAO, aberration is captured using Lukosz mode, and we use the low spatial frequency content of the image spectral density as the metric function. Simulations show that aberrations induced by the conformal window are dominated by some low-order Lukosz modes. To optimize the dynamic correction, we can only correct dominant Lukosz modes and the image size can be minimized to reduce the time required to compute the metric function. In our experiment, a 37-channel DM is used to mimic the dynamic aberration of conformal window with scanning rate of 10 degrees per second. A 52-channel DM is used for correction. For a 128 × 128 image, the mean value of image sharpness during dynamic correction is 1.436 × 10−5 in optimized correction and is 1.427 × 10−5 in un-optimized correction. We also demonstrated that model-based WSLAO can achieve convergence two times faster than traditional stochastic parallel gradient descent (SPGD) method. PMID:27598161

Long-term imaging in awake mice using removable cranial windows

PubMed Central

Glickfeld, Lindsey L.; Kerlin, Aaron M.; Reid, R. Clay; Bonin, Vincent; Schafer, Dorothy P.; Andermann, Mark L.

2015-01-01

Cranial window implants in head-fixed rodents are becoming a preparation of choice for stable optical access to large areas of cortex over extended periods of time. Here, we provide a highly detailed and reliable surgical protocol for a cranial window implantation procedure for chronic widefield and cellular imaging in awake, head-fixed mice, which enables subsequent window removal and replacement in the weeks and months following the initial craniotomy. This protocol has facilitated awake, chronic imaging in adolescent as well as adult mice over several months from a large number of cortical brain regions; targeted virus and tracer injections from data obtained using prior awake functional mapping; and functionally-targeted two-photon imaging across all cortical layers in awake mice using a microprism attachment to the cranial window. Collectively, these procedures extend the reach of chronic imaging of cortical function and dysfunction in behaving animals. PMID:25275789

Continuation of research into software for space operations support: Conversion of the display manager to X Windows/Motif, volume 2

NASA Technical Reports Server (NTRS)

Collier, Mark D.; Killough, Ronnie; Martin, Nancy L.

1990-01-01

NASA is currently using a set of applications called the Display Builder and Display Manager. They run on Concurrent systems and heavily depend on the Graphic Kernel System (GKS). At this time however, these two applications would more appropriately be developed in X Windows, in which a low X is used for all actual text and graphics display and a standard widget set (such as Motif) is used for the user interface. Use of the X Windows will increase performance, improve the user interface, enhance portability, and improve reliability. Prototype of X Window/Motif based Display Manager provides the following advantages over a GKS based application: improved performance by using a low level X Windows, display of graphic and text will be more efficient; improved user interface by using Motif; Improved portability by operating on both Concurrent and Sun workstations; and Improved reliability.

Censored Glauber Dynamics for the Mean Field Ising Model

NASA Astrophysics Data System (ADS)

Ding, Jian; Lubetzky, Eyal; Peres, Yuval

2009-11-01

We study Glauber dynamics for the Ising model on the complete graph on n vertices, known as the Curie-Weiss Model. It is well known that at high temperature ( β<1) the mixing time is Θ( nlog n), whereas at low temperature ( β>1) it is exp ( Θ( n)). Recently, Levin, Luczak and Peres considered a censored version of this dynamics, which is restricted to non-negative magnetization. They proved that for fixed β>1, the mixing-time of this model is Θ( nlog n), analogous to the high-temperature regime of the original dynamics. Furthermore, they showed cutoff for the original dynamics for fixed β<1. The question whether the censored dynamics also exhibits cutoff remained unsettled. In a companion paper, we extended the results of Levin et al. into a complete characterization of the mixing-time for the Curie-Weiss model. Namely, we found a scaling window of order 1/sqrt{n} around the critical temperature β c =1, beyond which there is cutoff at high temperature. However, determining the behavior of the censored dynamics outside this critical window seemed significantly more challenging. In this work we answer the above question in the affirmative, and establish the cutoff point and its window for the censored dynamics beyond the critical window, thus completing its analogy to the original dynamics at high temperature. Namely, if β=1+ δ for some δ>0 with δ 2 n→∞, then the mixing-time has order ( n/ δ)log ( δ 2 n). The cutoff constant is (1/2+[2(ζ2 β/ δ-1)]-1), where ζ is the unique positive root of g( x)=tanh ( β x)- x, and the cutoff window has order n/ δ.

Using exposure windows to explore an elusive biomarker: blood manganese.

PubMed

Baker, Marissa G; Stover, Bert; Simpson, Christopher D; Sheppard, Lianne; Seixas, Noah S

2016-05-01

We sought to understand the time course between exposure to manganese (Mn) and uptake into the blood, to allow a more meaningful interpretation of exposure biomarker data, and to determine the utility of blood as a biomarker of Mn exposure. Welder trainees were monitored over the course of a five-quarter training program. Each quarter, trainees gave eight blood samples and had personal air monitoring four times. A mixed model was fit to obtain estimates of airborne exposure by welding type (fixed effect), adjusted for subject (random effect). Considering weekends and days absent as zero exposure, estimated exposures were summed over various exposure windows and related to measured blood manganese (MnB) using a mixed model. A relationship consistent with zero was found between MnB and modeled 1 or 7 days of exposure. After 30 days of preceding exposure, a 1 mg-days/m(3) increase in air Mn is associated with a 0.57 ng/mL increase in MnB (95% CI -0.04, 1.19). Considering a 90-day exposure window and a cumulative exposure window, a 1 mg-days/m(3) increase in air Mn is associated with a 0.26 (95% CI 0.005, 0.51) and 0.09 (95% CI 0.006, 0.17) ng/mL increase in MnB, respectively. From this analysis, MnB may begin to act as a biomarker of Mn exposure over longer time periods, or at higher levels of exposure. This novel study design allowed investigation of how MnB relates to different time windows of exposure, representing the most robust Mn exposure assessment in the biomarker literature.

Ultrafast time-stretch imaging at 932 nm through a new highly-dispersive fiber

PubMed Central

Wei, Xiaoming; Kong, Cihang; Sy, Samuel; Ko, Ho; Tsia, Kevin K.; Wong, Kenneth K. Y.

2016-01-01

Optical glass fiber has played a key role in the development of modern optical communication and attracted the biotechnology researcher’s great attention because of its properties, such as the wide bandwidth, low attenuation and superior flexibility. For ultrafast optical imaging, particularly, it has been utilized to perform MHz time-stretch imaging with diffraction-limited resolutions, which is also known as serial time-encoded amplified microscopy (STEAM). Unfortunately, time-stretch imaging with dispersive fibers has so far mostly been demonstrated at the optical communication window of 1.5 μm due to lack of efficient dispersive optical fibers operating at the shorter wavelengths, particularly at the bio-favorable window, i.e., <1.0 μm. Through fiber-optic engineering, here we demonstrate a 7.6-MHz dual-color time-stretch optical imaging at bio-favorable wavelengths of 932 nm and 466 nm. The sensitivity at such a high speed is experimentally identified in a slow data-streaming manner. To the best of our knowledge, this is the first time that all-optical time-stretch imaging at ultrahigh speed, high sensitivity and high chirping rate (>1 ns/nm) has been demonstrated at a bio-favorable wavelength window through fiber-optic engineering. PMID:28018737

Time-frequency analysis-based time-windowing algorithm for the inverse synthetic aperture radar imaging of ships

NASA Astrophysics Data System (ADS)

Zhou, Peng; Zhang, Xi; Sun, Weifeng; Dai, Yongshou; Wan, Yong

2018-01-01

An algorithm based on time-frequency analysis is proposed to select an imaging time window for the inverse synthetic aperture radar imaging of ships. An appropriate range bin is selected to perform the time-frequency analysis after radial motion compensation. The selected range bin is that with the maximum mean amplitude among the range bins whose echoes are confirmed to be contributed by a dominant scatter. The criterion for judging whether the echoes of a range bin are contributed by a dominant scatter is key to the proposed algorithm and is therefore described in detail. When the first range bin that satisfies the judgment criterion is found, a sequence composed of the frequencies that have the largest amplitudes in every moment's time-frequency spectrum corresponding to this range bin is employed to calculate the length and the center moment of the optimal imaging time window. Experiments performed with simulation data and real data show the effectiveness of the proposed algorithm, and comparisons between the proposed algorithm and the image contrast-based algorithm (ICBA) are provided. Similar image contrast and lower entropy are acquired using the proposed algorithm as compared with those values when using the ICBA.

Ultrafast time-stretch imaging at 932 nm through a new highly-dispersive fiber.

PubMed

Wei, Xiaoming; Kong, Cihang; Sy, Samuel; Ko, Ho; Tsia, Kevin K; Wong, Kenneth K Y

2016-12-01

Optical glass fiber has played a key role in the development of modern optical communication and attracted the biotechnology researcher's great attention because of its properties, such as the wide bandwidth, low attenuation and superior flexibility. For ultrafast optical imaging, particularly, it has been utilized to perform MHz time-stretch imaging with diffraction-limited resolutions, which is also known as serial time-encoded amplified microscopy (STEAM). Unfortunately, time-stretch imaging with dispersive fibers has so far mostly been demonstrated at the optical communication window of 1.5 μm due to lack of efficient dispersive optical fibers operating at the shorter wavelengths, particularly at the bio-favorable window, i.e., <1.0 μm. Through fiber-optic engineering, here we demonstrate a 7.6-MHz dual-color time-stretch optical imaging at bio-favorable wavelengths of 932 nm and 466 nm. The sensitivity at such a high speed is experimentally identified in a slow data-streaming manner. To the best of our knowledge, this is the first time that all-optical time-stretch imaging at ultrahigh speed, high sensitivity and high chirping rate (>1 ns/nm) has been demonstrated at a bio-favorable wavelength window through fiber-optic engineering.