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Sample records for aid output snr

  1. Effects of WDRC release time and number of channels on output SNR and speech recognition

    PubMed Central

    Alexander, Joshua M.; Masterson, Katie

    2014-01-01

    Objectives The purpose of this study was to investigate the joint effects that wide dynamic range compression (WDRC) release time (RT) and number of channels have on recognition of sentences in the presence of steady and modulated maskers at different signal-to-noise ratios (SNRs). How the different combinations of WDRC parameters affect output SNR and the role this plays in the observed findings was also investigated. Design Twenty-four listeners with mild to moderate sensorineural hearing loss identified sentences mixed with steady or modulated maskers at 3 SNRs (−5, 0, +5 dB) that had been processed using a hearing aid simulator with 6 combinations of RT (40 and 640 ms) and number of channels (4, 8, and 16). Compression parameters were set using the Desired Sensation Level v5.0a prescriptive fitting method. For each condition, amplified speech and masker levels and the resultant long-term output SNR were measured. Results Speech recognition with WDRC depended on the combination of RT and number of channels, with the greatest effects observed at 0 dB input SNR, in which mean speech recognition scores varied by 10–12% across WDRC manipulations. Overall, effect sizes were generally small. Across both masker types and the three SNRs tested, the best speech recognition was obtained with 8 channels, regardless of RT. Increased speech levels, which favor audibility, were associated with the short RT and with an increase in the number of channels. These same conditions also increased masker levels by an even greater amount, for a net decrease in the long-term output SNR. Changes in long-term SNR across WDRC conditions were found to be strongly associated with changes in the temporal envelope shape as quantified by the Envelope Difference Index, however, neither of these factors fully explained the observed differences in speech recognition. Conclusions A primary finding of this study was that the number of channels had a modest effect when analyzed at each level of

  2. Perceptions of the Design of Voice Output Communication Aids

    ERIC Educational Resources Information Center

    Judge, Simon; Townend, Gillian

    2013-01-01

    Background: Voice output communication aids (VOCAs) are a key form of aided communication within the field of augmentative and alternative communication (AAC). In recent years, rapid developments in technology have resulted in an explosion of devices available commercially, yet little research has been conducted into what people who use VOCAs…

  3. Speech Intelligibility of Two Voice Output Communication Aids.

    ERIC Educational Resources Information Center

    Kannenberg, Patricia; And Others

    1988-01-01

    The intelligibility of two voice-output communication aids ("Personal Communicator" and "SpeechPAC'") was evaluated by presenting synthesized words and sentences to 20 listeners. Analysis of listener transcriptions revealed significantly higher intelligibility scores for the "Personal Communicator" compared to the "SpeechPAC" and higher scores for…

  4. A multiple model SNR/RCS likelihood ratio score for radar-based feature-aided tracking

    NASA Astrophysics Data System (ADS)

    Slocumb, Benjamin J.; Klusman, Michael E., III

    2005-09-01

    Most approaches to data association in target tracking use a likelihood-ratio based score for measurement-to-track and track-to-track matching. The classical approach uses a likelihood ratio based on kinematic data. Feature-aided tracking uses non-kinematic data to produce an "auxiliary score" that augments the kinematic score. This paper develops a nonkinematic likelihood ratio score based on statistical models for the signal-to-noise (SNR) and radar cross section (RCS) for use in narrowband radar tracking. The formulation requires an estimate of the target mean RCS, and a key challenge is the tracking of the mean RCS through significant "jumps" due to aspect dependencies. A novel multiple model approach is used track through the RCS jumps. Three solution are developed: one based on an α-filter, a second based on the median filter, and the third based on an IMM filter with a median pre-filter. Simulation results are presented that show the effectiveness of the multiple model approach for tracking through RCS transitions due to aspect-angle changes.

  5. Program Aids In Printing FORTRAN-Coded Output

    NASA Technical Reports Server (NTRS)

    Akian, Richard A.

    1993-01-01

    FORPRINT computer program prints FORTRAN-coded output files on most non-Postscript printers with such extra features as control of fonts for Epson and Hewlett Packard printers. Rewrites data to printer and inserts correct printer-control codes. Alternative uses include ability to separate data or ASCII file during printing by use of editing software to insert "1" in first column of data line that starts new page. Written in FORTRAN 77.

  6. The Microcomputer as an Efficient and Versatile Speech-Output Communication Aid.

    ERIC Educational Resources Information Center

    Rushakoff, G. Evan

    The use of microcomputers as communication aids for physically handicapped children and adults is described. Characteristics of stationary speech output communication aids addressed include encoding by single switch users, an easy to change vocabulary through the use of an "editor," capability to speak via synthesized speech in addition to…

  7. A Comprehensive Evaluation of the Effects of Voice Output Communication Aids on the Communicative Interactions of Students with Autism.

    ERIC Educational Resources Information Center

    Schepis, Maureen M.

    This report discusses the outcomes of a project that examined the acquisition and use of voice output communication aids in naturally occurring routines by four young children (ages 3-5) with autism. The effects of naturalistic teaching and the use of voice output communication aids (VOCAs) on communicative behaviors of the participants as well as…

  8. A voice-input voice-output communication aid for people with severe speech impairment.

    PubMed

    Hawley, Mark S; Cunningham, Stuart P; Green, Phil D; Enderby, Pam; Palmer, Rebecca; Sehgal, Siddharth; O'Neill, Peter

    2013-01-01

    A new form of augmentative and alternative communication (AAC) device for people with severe speech impairment-the voice-input voice-output communication aid (VIVOCA)-is described. The VIVOCA recognizes the disordered speech of the user and builds messages, which are converted into synthetic speech. System development was carried out employing user-centered design and development methods, which identified and refined key requirements for the device. A novel methodology for building small vocabulary, speaker-dependent automatic speech recognizers with reduced amounts of training data, was applied. Experiments showed that this method is successful in generating good recognition performance (mean accuracy 96%) on highly disordered speech, even when recognition perplexity is increased. The selected message-building technique traded off various factors including speed of message construction and range of available message outputs. The VIVOCA was evaluated in a field trial by individuals with moderate to severe dysarthria and confirmed that they can make use of the device to produce intelligible speech output from disordered speech input. The trial highlighted some issues which limit the performance and usability of the device when applied in real usage situations, with mean recognition accuracy of 67% in these circumstances. These limitations will be addressed in future work.

  9. A voice-input voice-output communication aid for people with severe speech impairment.

    PubMed

    Hawley, Mark S; Cunningham, Stuart P; Green, Phil D; Enderby, Pam; Palmer, Rebecca; Sehgal, Siddharth; O'Neill, Peter

    2013-01-01

    A new form of augmentative and alternative communication (AAC) device for people with severe speech impairment-the voice-input voice-output communication aid (VIVOCA)-is described. The VIVOCA recognizes the disordered speech of the user and builds messages, which are converted into synthetic speech. System development was carried out employing user-centered design and development methods, which identified and refined key requirements for the device. A novel methodology for building small vocabulary, speaker-dependent automatic speech recognizers with reduced amounts of training data, was applied. Experiments showed that this method is successful in generating good recognition performance (mean accuracy 96%) on highly disordered speech, even when recognition perplexity is increased. The selected message-building technique traded off various factors including speed of message construction and range of available message outputs. The VIVOCA was evaluated in a field trial by individuals with moderate to severe dysarthria and confirmed that they can make use of the device to produce intelligible speech output from disordered speech input. The trial highlighted some issues which limit the performance and usability of the device when applied in real usage situations, with mean recognition accuracy of 67% in these circumstances. These limitations will be addressed in future work. PMID:22875259

  10. Electroacoustic Comparison of Hearing Aid Output of Phonemes in Running Speech versus Isolation: Implications for Aided Cortical Auditory Evoked Potentials Testing

    PubMed Central

    Easwar, Vijayalakshmi; Purcell, David W.; Scollie, Susan D.

    2012-01-01

    Background. Functioning of nonlinear hearing aids varies with characteristics of input stimuli. In the past decade, aided speech evoked cortical auditory evoked potentials (CAEPs) have been proposed for validation of hearing aid fittings. However, unlike in running speech, phonemes presented as stimuli during CAEP testing are preceded by silent intervals of over one second. Hence, the present study aimed to compare if hearing aids process phonemes similarly in running speech and in CAEP testing contexts. Method. A sample of ten hearing aids was used. Overall phoneme level and phoneme onset level of eight phonemes in both contexts were compared at three input levels representing conversational speech levels. Results. Differences of over 3 dB between the two contexts were noted in one-fourth of the observations measuring overall phoneme levels and in one-third of the observations measuring phoneme onset level. In a majority of these differences, output levels of phonemes were higher in the running speech context. These differences varied across hearing aids. Conclusion. Lower output levels in the isolation context may have implications for calibration and estimation of audibility based on CAEPs. The variability across hearing aids observed could make it challenging to predict differences on an individual basis. PMID:23316236

  11. Effects of a Voice Output Communication Aid on Interactions between Support Personnel and an Individual with Multiple Disabilities.

    ERIC Educational Resources Information Center

    Schepis, Maureen M.; Reid, Dennis H.

    1995-01-01

    A young adult with multiple disabilities (profound mental retardation, spastic quadriplegia, and visual impairment) was provided with a voice output communication aid (VOCA) which allowed communication through synthesized speech. Both educational and residential staff members interacted with the individual more frequently when she had access to…

  12. Increasing Communicative Interactions of Young Children with Autism Using a Voice Output Communication Aid and Naturalistic Teaching.

    ERIC Educational Resources Information Center

    Schepis, Maureen M.; Reid, Dennis H.; Behrmann, Michael M.; Sutton, Kelly A.

    1998-01-01

    A study evaluated the effects of a voice output communication aid (VOCA) and naturalistic teaching procedures on the communicative interactions of four children (ages 3-5) with autism. Children showed increases in communicative interactions using VOCAs. There was no apparent reductive effect of VOCA use on other communicative behaviors. (Author/CR)

  13. The Effects of Enhanced Milieu Teaching and a Voice Output Communication Aid on the Requesting of Three Children with Autism

    ERIC Educational Resources Information Center

    Olive, Melissa L.; de la Cruz, Berenice; Davis, Tonya N.; Chan, Jeffrey M.; Lang, Russell B.; O'Reilly, Mark F.; Dickson, Sarah M.

    2007-01-01

    The purpose of this study was to evaluate the effects of enhanced milieu teaching when combined with a voice output communication aid on the requesting skills of three children with autism. The research design was a multiple probe across participants. All sessions were conducted during 5-min play sessions in the child's classroom. All three…

  14. Toward Functional Augmentative and Alternative Communication for Students with Autism: Manual Signs, Graphic Symbols, and Voice Output Communication Aids.

    ERIC Educational Resources Information Center

    Mirenda, Pat

    2003-01-01

    This article summarizes research regarding the delivery of augmentative and alternative communication (AAC) supports to students with autism. Focus is on: (1) what AAC modality is preferable to use (manual signs or graphic symbols); and (2) what is known about the use of voice output communication aids with people with autism. (Author/DB)

  15. Compairing Picture Exchange and Voice Output Communication Aids in Young Children with Autism

    ERIC Educational Resources Information Center

    Lorah, Elizabeth R.

    2012-01-01

    The Center for Disease Control estimates that one in 88 births result in a diagnosis of autism (CDC, 2012). Of those individuals diagnosed with autism approximately 25-61% fail to develop vocal output capabilities (Weitxz, Dexter, & Moore, 1997). The use of Augmentative and Alternative Communication (AAC) systems, such as Picture Exchange (PE)…

  16. Developing Snow Model Forcing Data From WRF Model Output to Aid in Water Resource Forecasting

    NASA Astrophysics Data System (ADS)

    Havens, S.; Marks, D. G.; Watson, K. A.; Masarik, M.; Flores, A. N.; Kormos, P.; Hedrick, A. R.

    2015-12-01

    Traditional operational modeling tools used by water managers in the west are challenged by more frequently occurring uncharacteristic stream flow patterns caused by climate change. Water managers are now turning to new models based on the physical processes within a watershed to combat the increasing number of events that do not follow the historical patterns. The USDA-ARS has provided near real time snow water equivalent (SWE) maps using iSnobal since WY2012 for the Boise River Basin in southwest Idaho and since WY2013 for the Tuolumne Basin in California that feeds the Hetch Hetchy reservoir. The goal of these projects is to not only provide current snowpack estimates but to use the Weather Research and Forecasting (WRF) model to drive iSnobal in order to produce a forecasted stream flow when coupled to a hydrology model. The first step is to develop methods on how to create snow model forcing data from WRF outputs. Using a reanalysis 1km WRF dataset from WY2009 over the Boise River Basin, WRF model results like surface air temperature, relative humidity, wind, precipitation, cloud cover, and incoming long wave radiation must be downscaled for use in iSnobal. iSnobal results forced with WRF output are validated at point locations throughout the basin, as well as compared with iSnobal results forced with traditional weather station data. The presentation will explore the differences in forcing data derived from WRF outputs and weather stations and how this affects the snowpack distribution.

  17. Rigorous Estimation of SNR of a PSK Communication Link

    NASA Technical Reports Server (NTRS)

    Manning, Robert M.

    2006-01-01

    An improved method of estimating the signal-to-noise ratio (SNR) of a phase-shift keying (PSK) communication link is founded on a rigorous statistical analysis of the input to, and the output from, the PSK demodulator in the receiver. The improved method is free of unwarranted simplifying assumptions and does not require the use of a propagation receiver.

  18. Similarity in loudness and distortion product otoacoustic emission input/output functions: implications for an objective hearing aid adjustment.

    PubMed

    Müller, Jörg; Janssen, Thomas

    2004-06-01

    The aim of the present study was to compare distortion product otoacoustic emissions (DPOAEs) to loudness with regard to the potentiality of DPOAEs to determine characteristic quantities of the cochlear-impaired ear and to derive objective hearing aid parameters. Recently, Neely et al. [J. Acoust. Soc. Am. 114, 1499-1507 (2003)] compared DPOAE input/output functions to the Fletcher and Munson [J. Acoust. Soc. Am. 5, 82-108 (1933)] loudness function finding a close resemblance in the slope characteristics of both measures. The present study extended their work by performing both loudness and DPOAE measurements in the same subject sample, and by developing a method for the estimation of gain needed to compensate for loss of cochlear sensitivity and compression. DPOAEs and loudness exhibited similar behavior when plotted on a logarithmic scale and slope increased with increasing hearing loss, confirming the findings of Neely et al. To compensate for undesired nonpathological impacts on the magnitude of DPOAE level, normalization of DPOAE data was implemented. A close resemblance between gain functions based on loudness and normalized DPOAE data was achieved. These findings suggest that DPOAEs are able to quantify the loss of cochlear sensitivity and compression and thus might provide parameters for a noncooperative hearing aid adjustment.

  19. Increasing communicative interactions of young children with autism using a voice output communication aid and naturalistic teaching.

    PubMed

    Schepis, M M; Reid, D H; Behrmann, M M; Sutton, K A

    1998-01-01

    We evaluated the effects of a voice output communication aid (VOCA) and naturalistic teaching procedures on the communicative interactions of young children with autism. A teacher and three assistants were taught to use naturalistic teaching strategies to provide opportunities for VOCA use in the context of regularly occurring classroom routines. Naturalistic teaching procedures and VOCA use were introduced in multiple probe fashion across 4 children and two classroom routines (snack and play). As the procedures were implemented, all children showed increases in communicative interactions using VOCAs. Also, there was no apparent reductive effect of VOCA use within the naturalistic teaching paradigm on other communicative behaviors. Teachers' ratings of children's VOCA communication, as well as ratings of a person unfamiliar with the children, supported the contextual appropriateness of the VOCA. Probes likewise indicated that the children used the VOCAs for a variety of different messages including requests, yes and no responses, statements, and social comments. Results are discussed in regard to the potential benefits of a VOCA when combined with naturalistic teaching procedures. Future research needs are also discussed, focusing on more precise identification of the attributes of VOCA use for children with autism, as well as for their support personnel.

  20. Using a Single-Switch Voice Output Communication Aid to Increase Social Access for Children with Severe Disabilities in Inclusive Classrooms

    ERIC Educational Resources Information Center

    Cosbey, Joanna Evans; Johnston, Susan

    2006-01-01

    Three young children with severe, multiple disabilities were taught to utilize a voice output communication aid (VOCA) to request access to preferred items and/or peers during play activities. Acquisition of VOCA use resulted from a naturalistic intervention strategy that consisted of creating communication opportunities, prompting the participant…

  1. An Analysis of the Effects of Functional Communication and a Voice Output Communication Aid for a Child with Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Olive, Melissa L.; Lang, Russell B.; Davis, Tonya N.

    2008-01-01

    The purpose of this study was to examine the effects of Functional Communication Training (FCT) and a Voice Output Communication Aid (VOCA) on the challenging behavior and language development of a 4-year-old girl with autism spectrum disorder. The participant's mother implemented modified functional analysis (FA) and intervention procedures in…

  2. SNR estimation for the baseband assembly

    NASA Technical Reports Server (NTRS)

    Simon, M. K.; Mileant, A.

    1986-01-01

    The expected value and the variance of the Baseband Assembly symbol signal-to-noise ratio (SNR) estimation algorithm are derived. The SNR algorithm treated here is designated as the Split Symbol Moments Estimator (SSME). It consists of averaging the first two moments of the integrated half symbols. The SSME is a biased, consistent estimator. The SNR degradation factor due to the jitter in the subcarrier demodulation and symbol synchronization loops is taken into account. Curves of the expected value of the SNR estimator versus the actual SNR are presented.

  3. Carrier tracking by smoothing filter improves symbol SNR

    NASA Technical Reports Server (NTRS)

    Pomalaza-Raez, Carlos A.; Hurd, William J.

    1986-01-01

    The potential benefit of using a smoothing filter to estimate carrier phase over use of phase locked loops (PLL) is determined. Numerical results are presented for the performance of three possible configurations of the deep space network advanced receiver. These are residual carrier PLL, sideband aided residual carrier PLL, and finally sideband aiding with a Kalman smoother. The average symbol signal to noise ratio (SNR) after losses due to carrier phase estimation error is computed for different total power SNRs, symbol rates and symbol SNRs. It is found that smoothing is most beneficial for low symbol SNRs and low symbol rates. Smoothing gains up to 0.4 dB over a sideband aided residual carrier PLL, and the combined benefit of smoothing and sideband aiding relative to a residual carrier loop is often in excess of 1 dB.

  4. GD-aided IOL (input-output linearisation) controller for handling affine-form nonlinear system with loose condition on relative degree

    NASA Astrophysics Data System (ADS)

    Zhang, Yunong; Chen, Dechao; Jin, Long; Zhang, Yinyan; Yin, Yonghua

    2016-04-01

    Input-output linearisation (IOL) may encounter a singularity problem when applied to the tracking control of affine-form nonlinear system (AFNS), which may not have a well-defined relative degree. The singularity problem has occurred in the area of control for decades. In this paper, we incorporate the gradient dynamics (GD) into IOL, which leads to the GD-aided IOL method to solve the singularity problem, with the proposition of the loose condition on relative degree. Moreover, detailed theoretical analyses on tracking-error bound and convergence performance of the corresponding GD-aided IOL controller are presented. Simulations and comparisons substantiate that the proposed GD-aided IOL method is capable of completing the tracking-control task and conquering the singularity encountered in the AFNS.

  5. The influence of SNR on MTF measurement

    NASA Astrophysics Data System (ADS)

    Zhang, Muxin; Liu, Liying; Li, Ye; Huan, Kewei; Zheng, Feng; Shi, Xiaoguang

    2015-11-01

    The Modulation Transfer Function (MTF) is a fundamental imaging system design specification and system quality metric often used in remote sensing. The MTF describes the attenuation of sinusoidal waveforms as a function of spatial frequency. Practically, MTF is a metric quantifying the sharpness of the reconstructed image. The Knife-Edge method is becoming widely applied for its advantage of simplified target and accurate computer calculation. Noise in CCD image system is inevitable, thus the SNR becomes a factor influencing the MTF measurement. In this paper, we build relationships between SNR, luminance and MTF. In conclusion, SNR is related with luminance levels linearly. SNR rises with increasing luminance. The higher SNR, the more curves conform to the theoretical MTF.

  6. SNR characterization in distributed acoustic sensing

    NASA Astrophysics Data System (ADS)

    Gabai, Haniel; Eyal, Avishay

    2016-05-01

    In this paper we study the SNR associated with acoustic detection in Rayleigh-based Distributed Acoustic Sensing (DAS) systems. The study is focused on phase sensitive DAS due to its superiority in terms of linearity and sensitivity. Since DAS is based on coherent interference of backscattered light from multiple scatterers it is prone to signal fading. When left unresolved, the issue of signal fading renders the associated SNR randomly dependent on position and time. Hence, its proper measurement and characterization requires statistical tools. Here such tools are introduced and a methodology for finding the mean SNR and its distribution is implemented in both experiment and simulation. It is shown that the distribution of the DAS-SNR can be obtained from the distribution of backscattered power in OTDR and the mean DAS-SNR is proportional to the energy of the interrogation pulse.

  7. Ranking Hearing Aid Input-Output Functions for Understanding Low-, Conversational-, and High-Level Speech in Multitalker Babble

    ERIC Educational Resources Information Center

    Chung, King; Killion, Mead C.; Christensen, Laurel A.

    2007-01-01

    Purpose: To determine the rankings of 6 input-output functions for understanding low-level, conversational, and high-level speech in multitalker babble without manipulating volume control for listeners with normal hearing, flat sensorineural hearing loss, and mildly sloping sensorineural hearing loss. Method: Peak clipping, compression limiting,…

  8. Long-term signal-to-noise ratio at the input and output of amplitude-compression systems.

    PubMed

    Naylor, Graham; Johannesson, René Burmand

    2009-03-01

    We present measurements showing that the long-term signal-to-noise ratio (SNR) at the output of an amplification system that includes amplitude compression may be higher or lower than the long-term SNR at the input, dependent on interactions among the actual long-term input SNR, the modulation characteristics of the signal and noise being mixed, and the amplitude compression characteristics of the system under test. The effects demonstrated with the measurements shown here have implications for choices of test methods when comparing alternative hearing aid systems. The results of speech-recognition tests intended to compare alternative systems may be misleading or misinterpreted if the above interactions are not considered.

  9. Comparison of IRST systems by SNR

    NASA Astrophysics Data System (ADS)

    Kim, Charles C.; Meyer, Ron

    2014-05-01

    Infrared (IR) cameras are widely used in systems to search and track. IR search and track (IRST) systems are most often available in one of two distinct spectral bands: mid-wave IR (MWIR) or long-wave IR (LWIR). Many have compared both systems in a number of ways. The comparison included field data and analysis under different scenarios. Yet, it is a challenge to make a right decision in choosing one band over the other band for a new scenario. In some respects, the attempt is like choosing between an apple and an orange. The signal-to-noise ratio (SNR) of a system for a point-like target is one criterion that helps one to make an informed decision. The formula for SNR commonly uses noise equivalent irradiance (NEI) that requires front optics. Such formalism cannot compare two bands before a camera is built complete with front optics. We derive a formula for SNR that utilizes noise equivalent differential temperature (NEDT) that does not require front optics. The formula is further simplified under some assumptions, which identifies critical parameters and provides an insight in comparing two bands. We have shown an example for a simple case.

  10. Exploring the effectiveness of the output-based aid voucher program to increase uptake of gender-based violence recovery services in Kenya: A qualitative evaluation

    PubMed Central

    2012-01-01

    Background Few studies in Africa have explored in detail the ability of output-based aid (OBA) voucher programs to increase access to gender-based violence recovery (GBVR) services. Methods A qualitative study was conducted in 2010 and involved: (i) in-depth interviews (IDIs) with health managers, service providers, voucher management agency (VMA) managers and (ii) focus group discussions (FGDs) with voucher users, voucher non-users, voucher distributors and opinion leaders drawn from five program sites in Kenya. Results The findings showed promising prospects for the uptake of OBA GBVR services among target population. However, a number of factors affect the uptake of the services. These include lack of general awareness of the GBVR services vouchers, lack of understanding of the benefit package, immediate financial needs of survivors, as well as stigma and cultural beliefs that undermine reporting of cases or seeking essential medical services. Moreover, accreditation of only hospitals to offer GBVR services undermines access to the services in rural areas. Poor responsiveness from law enforcement agencies and fear of reprisal from perpetrators also undermine treatment options and access to medical services. Low provider knowledge on GBVR services and lack of supplies also affect effective provision and management of GBVR services. Conclusions The above findings suggest that there is a need to build the capacity of health care providers and police officers, strengthen the community strategy component of the OBA program to promote the GBVR services voucher, and conduct widespread community education programs aimed at prevention, ensuring survivors know how and where to access services and addressing stigma and cultural barriers. PMID:22691436

  11. A CHANDRA OBSERVATION OF SNR 0540 - 697

    SciTech Connect

    Seward, F. D.; Williams, R. M.; Chu, Y.-H.; Gruendl, R. A.; Dickel, J. R.

    2010-07-15

    This paper describes a Chandra observation of SNR 0540 - 697 within the H II complex N159 in the Large Magellanic Cloud (LMC). Scattering from the nearby bright source LMC X-1, which obscures the western edge of the remnant, has been removed. Larger than previously believed, the 2.'0 x 2.'8 remnant is defined by optical filaments and two lobes of X-ray emission. A band of intervening material absorbs X-rays from the central part of the remnant. The N Lobe of the remnant is relatively bright and well defined, while emission from the S Lobe is much weaker. There is structure within the N Lobe but no clear X-ray emission from an outer shell indicating a shock in the interstellar medium. The X-ray spectrum is thermal with emission lines from Fe, Mg, and Si. The observed temperature and luminosity of the hot gas are 0.6 keV and 6 x 10{sup 35} erg s{sup -1}, respectively. These are consistent with characteristics expected for older remnants. There is also diffuse thermal X-ray emission north of N159 extending into N160, evidence for a larger remnant or bubble.

  12. CO observation of SNR IC 443

    NASA Astrophysics Data System (ADS)

    Zhang, Zhiyu; Gao, Yu; Wang, Junzhi

    2010-07-01

    We present our 12CO and 13CO mapping observations of SNR IC 443 interacting with molecular clouds. It is the first large-scale high-resolution 13CO mapping observation in the surrounding region. The morphologies of IC 443 in 12CO and 13CO are compared with the optical, infrared, Spitzer far-infrared, X-ray, and neutral atomic gas (HI). We also make comparison and analysis in the kinematics, using the date-cubes of 12CO, 13CO and HI, to help distinguish the complicated gas motions in the shocked regions. Based on the work of Wang & Scoville (1992), we present a new model to explain the coexistence of multiple shocks with different speeds in a pc-scale region at the central clump B. We test this new model by analyzing the HI and CO distribution in both velocity and space domain. We also establish the relationship between the dissociation rate of shocked molecular gas and the shock velocity in this region. Finally, we derive the optical depth of 12CO with the 13CO spectra in clump B, and discuss the validity of the assumption of optically thin emission for the shocked 12CO.

  13. Impact of CCD camera SNR on polarimetric accuracy.

    PubMed

    Chen, Zhenyue; Wang, Xia; Pacheco, Shaun; Liang, Rongguang

    2014-11-10

    A comprehensive charge-coupled device (CCD) camera noise model is employed to study the impact of CCD camera signal-to-noise ratio (SNR) on polarimetric accuracy. The study shows that the standard deviations of the measured degree of linear polarization (DoLP) and angle of linear polarization (AoLP) are mainly dependent on the camera SNR. With increase in the camera SNR, both the measurement errors and the standard deviations caused by the CCD camera noise decrease. When the DoLP of the incident light is smaller than 0.1, the camera SNR should be at least 75 to achieve a measurement error of less than 0.01. When the input DoLP is larger than 0.5, a SNR of 15 is sufficient to achieve the same measurement accuracy. An experiment is carried out to verify the simulation results.

  14. Real-time Signal-to-noise Ratio (SNR) Estimation for BPSK and QPSK Modulation Using the Active Communications Channel

    NASA Technical Reports Server (NTRS)

    Manning, Robert M. (Inventor)

    2007-01-01

    Method and apparatus for estimating signal-to-noise ratio (SNR) gamma of a composite input signal e(t) on a phase modulated (e.g., BPSK) communications link. A first demodulator receives the composite input signal and a stable carrier signal and outputs an in-phase output signal; a second demodulator receives the composite input signal and a phase-shifted version of the carrier signal and outputs a quadrature-phase output signal; and phase error theta(sub E)(t) contained within the composite input signal e(t) is calculated from the outputs of the first and second demodulators. A time series of statistically independent phase error measurements theta(sub E)(t(sub 1)), theta (sub E)(t(sub 2)),..., theta (sub E)(t(sub k)) is obtained from the composite input signal subtending a time interval delta t = t(sub k) - t(sub 1) whose value is small enough such that gamma(t) and sigma(t) can be taken to be constant in delta t. A biased estimate gamma(sup *) for the signal-to-noise ratio (SNR) gamma if the composite input signal is calculated using maximum likelihood (ML) estimation techniques, and an unbiased estimate gamma(sup ^) for the signal-to-noise ratio (SNR) gamma of the composite input signal is determined from the biased estimate gamma(sup *), such as by use of a look-up table.

  15. Analysis and improvement of SNR using time slicing

    NASA Astrophysics Data System (ADS)

    Karanam, Srikrishna; Singh, Amarjot; Kumar, Devinder; Choubey, Akash; Bacchuwar, Ketan

    2011-06-01

    Noise is a very important factor which in most cases, plays an antagonistic role in the vast field of image processing. Thus noise needs to be studied in great depth in order to improve the quality of images. The quantity of signal in an image, corrupted by noise is generally described by the term Signal-to-Noise ratio. Capturing multiple photos at different focus settings is a powerful approach for improving SNR. The paper analyses a frame work for optimally balancing the tradeoff's between defocus and sensor noise by experimenting on synthetic as well as real video sequences. The method is first applied to synthetic image where the improvement in SNR is studied by the ability of Hough transform to extract the number of lines with respect to the variation in SNR. The paper further experiments on real time video sequences while the improvement in SNR is analyzed using different edge operators like Sobel, Canny, Prewitt, Roberts and Laplacian. The result obtained is further analyzed using different edge operators. The main aim is to detect the edges at different values of SNR which will be a prominent measure of the signal strength as well as clarity of an image. The paper also explains in depth the modeling of noise leading to better understanding of SNR. The results obtain from both synthetic image and real time video sequences elaborate the increase in SNR with the increment in the total number of time slices in a fixed budget leading to clear pictures. This technique can be very effectively applied to capture high quality images from long distances.

  16. CMOS output buffer wave shaper

    NASA Technical Reports Server (NTRS)

    Albertson, L.; Whitaker, S.; Merrell, R.

    1990-01-01

    As the switching speeds and densities of Digital CMOS integrated circuits continue to increase, output switching noise becomes more of a problem. A design technique which aids in the reduction of switching noise is reported. The output driver stage is analyzed through the use of an equivalent RLC circuit. The results of the analysis are used in the design of an output driver stage. A test circuit based on these techniques is being submitted to MOSIS for fabrication.

  17. Basal ganglia outputs map instantaneous position coordinates during behavior.

    PubMed

    Barter, Joseph W; Li, Suellen; Sukharnikova, Tatyana; Rossi, Mark A; Bartholomew, Ryan A; Yin, Henry H

    2015-02-11

    The basal ganglia (BG) are implicated in many movement disorders, yet how they contribute to movement remains unclear. Using wireless in vivo recording, we measured BG output from the substantia nigra pars reticulata (SNr) in mice while monitoring their movements with video tracking. The firing rate of most nigral neurons reflected Cartesian coordinates (either x- or y-coordinates) of the animal's head position during movement. The firing rates of SNr neurons are either positively or negatively correlated with the coordinates. Using an egocentric reference frame, four types of neurons can be classified: each type increases firing during movement in a particular direction (left, right, up, down), and decreases firing during movement in the opposite direction. Given the high correlation between the firing rate and the x and y components of the position vector, the movement trajectory can be reconstructed from neural activity. Our results therefore demonstrate a quantitative and continuous relationship between BG output and behavior. Thus, a steady BG output signal from the SNr (i.e., constant firing rate) is associated with the lack of overt movement, when a stable posture is maintained by structures downstream of the BG. Any change in SNr firing rate is associated with a change in position (i.e., movement). We hypothesize that the SNr output quantitatively determines the direction, velocity, and amplitude of voluntary movements. By changing the reference signals to downstream position control systems, the BG can produce transitions in body configurations and initiate actions.

  18. Basal ganglia outputs map instantaneous position coordinates during behavior.

    PubMed

    Barter, Joseph W; Li, Suellen; Sukharnikova, Tatyana; Rossi, Mark A; Bartholomew, Ryan A; Yin, Henry H

    2015-02-11

    The basal ganglia (BG) are implicated in many movement disorders, yet how they contribute to movement remains unclear. Using wireless in vivo recording, we measured BG output from the substantia nigra pars reticulata (SNr) in mice while monitoring their movements with video tracking. The firing rate of most nigral neurons reflected Cartesian coordinates (either x- or y-coordinates) of the animal's head position during movement. The firing rates of SNr neurons are either positively or negatively correlated with the coordinates. Using an egocentric reference frame, four types of neurons can be classified: each type increases firing during movement in a particular direction (left, right, up, down), and decreases firing during movement in the opposite direction. Given the high correlation between the firing rate and the x and y components of the position vector, the movement trajectory can be reconstructed from neural activity. Our results therefore demonstrate a quantitative and continuous relationship between BG output and behavior. Thus, a steady BG output signal from the SNr (i.e., constant firing rate) is associated with the lack of overt movement, when a stable posture is maintained by structures downstream of the BG. Any change in SNr firing rate is associated with a change in position (i.e., movement). We hypothesize that the SNr output quantitatively determines the direction, velocity, and amplitude of voluntary movements. By changing the reference signals to downstream position control systems, the BG can produce transitions in body configurations and initiate actions. PMID:25673860

  19. SNR of swept SLEDs and swept lasers for OCT.

    PubMed

    Johnson, Bart; Atia, Walid; Flanders, Dale C; Kuznetsov, Mark; Goldberg, Brian D; Kemp, Nate; Whitney, Peter

    2016-05-16

    A back-to-back comparison of a tunable narrow-band-filtered SLED (TSLED) and a swept laser are made for OCT applications. The two sources are similar in terms of sweep speed, tuning range and coherence length. A fundamental issue with a TSLED is that the RIN is proportional to 1/linewidth, meaning that the longer the coherence length, the higher the RIN and clock jitter. We show that the TSLED has an SNR limit that causes noise streaks at points of high reflection in images. The laser, which is shot noise limited, does not exhibit this effect. We add noise terms proportional to the sample power times reference power to standard swept source SNR expressions to account for the SNR limit. PMID:27409939

  20. Customer oriented SNR scalability scheme for scalable video coding

    NASA Astrophysics Data System (ADS)

    Li, Z. G.; Rahardja, S.

    2005-07-01

    Let the whole region be the whole bit rate range that customers are interested in, and a sub-region be a specific bit rate range. The weighting factor of each sub-region is determined according to customers' interest. A new type of region of interest (ROI) is defined for the SNR scalability as the gap between the coding efficiency of SNR scalability scheme and that of the state-of-the-art single layer coding for a sub-region is a monotonically non-increasing function of its weighting factor. This type of ROI is used as a performance index to design a customer oriented SNR scalability scheme. Our scheme can be used to achieve an optimal customer oriented scalable tradeoff (COST). The profit can thus be maximized.

  1. Tracking low SNR targets using particle filter with flow control

    NASA Astrophysics Data System (ADS)

    Moshtagh, Nima; Romberg, Paul M.; Chan, Moses W.

    2014-06-01

    In this work we study the problem of detecting and tracking challenging targets that exhibit low signal-to-noise ratios (SNR). We have developed a particle filter-based track-before-detect (TBD) algorithm for tracking such dim targets. The approach incorporates the most recent state estimates to control the particle flow accounting for target dynamics. The flow control enables accumulation of signal information over time to compensate for target motion. The performance of this approach is evaluated using a sensitivity analysis based on varying target speed and SNR values. This analysis was conducted using high-fidelity sensor and target modeling in realistic scenarios. Our results show that the proposed TBD algorithm is capable of tracking targets in cluttered images with SNR values much less than one.

  2. Whole Symbol Moments SNR Estimator (WSME) Analysis and Implementation

    NASA Astrophysics Data System (ADS)

    Kuperman, I.; Satorius, E.

    2012-08-01

    Adaptive data rate (ADR) functionality was added to the Mars Reconnaissance Orbiter (MRO) Electra software-defined radio (SDR) via software and firmware uploads to its modem in October 2011. An integral part of ADR is the symbol signal-to-noise ratio (SNR) estimation algorithm. The Whole Symbol Moments SNR Estimator (WSME) algorithm has been developed for ADR control and was included in the October 2011 upload. It is the subject of this article. The WSME architecture is described and performance results are presented via analysis, simulation, and data from an inflight MRO test on March 5, 2012.

  3. Improved Diffusion Imaging through SNR-Enhancing Joint Reconstruction

    PubMed Central

    Haldar, Justin P.; Wedeen, Van J.; Nezamzadeh, Marzieh; Dai, Guangping; Weiner, Michael W.; Schuff, Norbert; Liang, Zhi-Pei

    2012-01-01

    Quantitative diffusion imaging is a powerful technique for the characterization of complex tissue microarchitecture. However, long acquisition times and limited signal-to-noise ratio (SNR) represent significant hurdles for many in vivo applications. This paper presents a new approach to reduce noise while largely maintaining resolution in diffusion weighted images, using a statistical reconstruction method that takes advantage of the high level of structural correlation observed in typical datasets. Compared to existing denoising methods, the proposed method performs reconstruction directly from the measured complex k-space data, allowing for Gaussian noise modeling and theoretical characterizations of the resolution and SNR of the reconstructed images. In addition, the proposed method is compatible with many different models of the diffusion signal (e.g., diffusion tensor modeling, q-space modeling, etc.). The joint reconstruction method can provide significant improvements in SNR relative to conventional reconstruction techniques, with a relatively minor corresponding loss in image resolution. Results are shown in the context of diffusion spectrum imaging tractography and diffusion tensor imaging, illustrating the potential of this SNR-enhancing joint reconstruction approach for a range of different diffusion imaging experiments. PMID:22392528

  4. Hearing-aid tester

    NASA Technical Reports Server (NTRS)

    Kessinger, R.; Polhemus, J. T.; Waring, J. G.

    1977-01-01

    Hearing aids are automatically checked by circuit that applies half-second test signal every thirty minutes. If hearing-aid output is distorted, too small, or if battery is too low, a warning lamp is activated. Test circuit is incorporated directly into hearing-aid package.

  5. SNR improvement for hyperspectral application using frame and pixel binning

    NASA Astrophysics Data System (ADS)

    Rehman, Sami Ur; Kumar, Ankush; Banerjee, Arup

    2016-05-01

    Hyperspectral imaging spectrometer systems are increasingly being used in the field of remote sensing for variety of civilian and military applications. The ability of such instruments in discriminating finer spectral features along with improved spatial and radiometric performance have made such instruments a powerful tool in the field of remote sensing. Design and development of spaceborne hyper spectral imaging spectrometers poses lot of technological challenges in terms of optics, dispersion element, detectors, electronics and mechanical systems. The main factors that define the type of detectors are the spectral region, SNR, dynamic range, pixel size, number of pixels, frame rate, operating temperature etc. Detectors with higher quantum efficiency and higher well depth are the preferred choice for such applications. CCD based Si detectors serves the requirement of high well depth for VNIR band spectrometers but suffers from smear. Smear can be controlled by using CMOS detectors. Si CMOS detectors with large format arrays are available. These detectors generally have smaller pitch and low well depth. Binning technique can be used with available CMOS detectors to meet the large swath, higher resolution and high SNR requirements. Availability of larger dwell time of satellite can be used to bin multiple frames to increase the signal collection even with lesser well depth detectors and ultimately increase the SNR. Lab measurements reveal that SNR improvement by frame binning is more in comparison to pixel binning. Effect of pixel binning as compared to the frame binning will be discussed and degradation of SNR as compared to theoretical value for pixel binning will be analyzed.

  6. Chandra ACIS Survey of M33: The SNR Population

    NASA Astrophysics Data System (ADS)

    Plucinsky, Paul; Long, Knox S.; Gaetz, Terrance; Tuellmann, Ralph

    The Chandra ACIS Survey of M33 (ChASeM33) is a large program to survey the inner re-gions of the M33 galaxy. The survey consists of 7 different fields observed for 200 ks (each field observed twice for 100 ks), covering 70the key projects of the ChASeM33 project is to characterize the SNR population in M33. We have detected 82 of 137 optically-identified SNRs and SNR candidates with a limiting X-ray luminosity of 2.0e34 ergs/s (0.35-2.0 keV), yielding confirmation of (or at least strongly supporting) their SNR identifications. This represents the largest sample of remnants detected at optical and X-ray wavelengths in any galaxy, including the Milky Way. With the high angular resolution of Chandra, we are able to study the X-ray morphology of the bright remnants for the first time. A spectral analysis of the seven X-ray brightest SNRs reveals that two, G98-31 and G98-35, have spectra that appear to indicate enrichment by ejecta from core-collapse supernova explosions. A comparison of the X-ray lu-minosity function of the SNRs in M33 to the LMC and SMC indicates that the LMC, and to a lesser extent the SMC, have more, high luminosity SNRs than M33. We did not discover any close analogs of Cas A, Kepler's SNR, Tycho's SNR or the Crab Nebula in the regions of M33 surveyed, but we have found an X-ray source with a power law spectrum coincident with a small-diameter radio source that may be the first pulsar-wind nebula recognized in M33.

  7. HYPR: constrained reconstruction for enhanced SNR in dynamic medical imaging

    NASA Astrophysics Data System (ADS)

    Mistretta, C.; Wieben, O.; Velikina, J.; Wu, Y.; Johnson, K.; Korosec, F.; Unal, O.; Chen, G.; Fain, S.; Christian, B.; Nalcioglu, O.; Kruger, R. A.; Block, W.; Samsonov, A.; Speidel, M.; Van Lysel, M.; Rowley, H.; Supanich, M.; Turski, P.; Wu, Yan; Holmes, J.; Kecskemeti, S.; Moran, C.; O'Halloran, R.; Keith, L.; Alexander, A.; Brodsky, E.; Lee, J. E.; Hall, T.; Zagzebski, J.

    2008-03-01

    During the last eight years our group has developed radial acquisitions with angular undersampling factors of several hundred that accelerate MRI in selected applications. As with all previous acceleration techniques, SNR typically falls as least as fast as the inverse square root of the undersampling factor. This limits the SNR available to support the small voxels that these methods can image over short time intervals in applications like time-resolved contrast-enhanced MR angiography (CE-MRA). Instead of processing each time interval independently, we have developed constrained reconstruction methods that exploit the significant correlation between temporal sampling points. A broad class of methods, termed HighlY Constrained Back PRojection (HYPR), generalizes this concept to other modalities and sampling dimensions.

  8. Radiometric calibration and SNR calculation of a SWIR imaging telescope

    SciTech Connect

    Yilmaz, Ozgur; Turk, Fethi; Selimoglu, Ozgur

    2012-09-06

    Radiometric calibration of an imaging telescope is usually made using a uniform illumination sphere in a laboratory. In this study, we used the open-sky images taken during bright day conditions to calibrate our telescope. We found a dark signal offset value and a linear response coefficient value for each pixel by using three different algorithms. Then we applied these coefficients to the taken images, and considerably lowered the image non-uniformity. Calibration can be repeated during the operation of telescope with an object that has better uniformity than open-sky. Also SNR (Signal to Noise Ratio) of each pixel was calculated from the open-sky images using the temporal mean and standard deviations. It is found that SNR is greater than 80 for all pixels even at low light levels.

  9. Stochastic acceleration and magnetic damping in Tycho's SNR

    NASA Astrophysics Data System (ADS)

    Wilhelm, Alina; Telezhinsky, Igor; Dwarkadas, Vikram; Pohl, Martin

    2016-06-01

    Tycho's Supernova remnant (SNR) is also known as historical Supernova SN 1572 of Type Ia. Having exploded in a relatively clean environment and with a known age, it represents an ideal astrophysical testbed for the study of cosmic-ray acceleration and related phenomena. A number of studies suggest that shock acceleration with very efficient magnetic-field amplification is needed to explain the rather soft radio spectrum and the narrow rims observed in X-rays. We show that the wideband spectrum of Tycho's SNR can be alternatively well explained when accounting for stochastic acceleration as a secondary process. The re-acceleration of particles in the turbulent region immediately downstream of the shock provided by the fast-mode waves is efficient enough to impact particle spectra over several decades in energy. Our self-consistent model contains hydrodynamic simulations of the SNR plasma flow. The particle spectra are obtained from the time-dependent transport equation and the background magnetic field is computed either from the induction equation or it follows analytic profiles depending on the considered model. Although not as efficient as standard diffusive shock acceleration, stochastic acceleration leaves its imprint on the particle spectra. This is especially notable in the emission at radio wavelengths and soft γ-rays. Excessively strong magnetic fields and the so-called Alfvénic drift are not required in this scenario. The narrow X-ray and radio rims arise from damping of the turbulent magnetic field. We find a lower limit for the downstream magnetic field strength, Bd = 173 µG and investigate the energy-dependence of the X-ray filament width. We conclude that stochastic re-acceleration is an important mechanism for modifying particle and emission spectra in SNR and that the magnetic-field damping should be taken into account to properly explain the synchrotron intensity profiles of Tycho.

  10. A new method of pulse edge detection in low SNR

    NASA Astrophysics Data System (ADS)

    Fan, Xiaolei; Li, Tao; Su, Shaoying; Chen, Zengping

    2015-12-01

    In this paper, we propose a new pulse edge detection method based on short time Fourier transform (STFT) and difference of boxes (DOB) filter. Firstly, detect the coarse starting and ending positions in frequency domain after STFT. Then obtain the precise pulse edge through DOB filter. It achieves a better performance than the classical energy detection (ED) method, especially when signal to noise ratio (SNR) is low. Simulation results and real data application validate the effectiveness of the proposed method.

  11. SNR-adaptive stream weighting for audio-MES ASR.

    PubMed

    Lee, Ki-Seung

    2008-08-01

    Myoelectric signals (MESs) from the speaker's mouth region have been successfully shown to improve the noise robustness of automatic speech recognizers (ASRs), thus promising to extend their usability in implementing noise-robust ASR. In the recognition system presented herein, extracted audio and facial MES features were integrated by a decision fusion method, where the likelihood score of the audio-MES observation vector was given by a linear combination of class-conditional observation log-likelihoods of two classifiers, using appropriate weights. We developed a weighting process adaptive to SNRs. The main objective of the paper involves determining the optimal SNR classification boundaries and constructing a set of optimum stream weights for each SNR class. These two parameters were determined by a method based on a maximum mutual information criterion. Acoustic and facial MES data were collected from five subjects, using a 60-word vocabulary. Four types of acoustic noise including babble, car, aircraft, and white noise were acoustically added to clean speech signals with SNR ranging from -14 to 31 dB. The classification accuracy of the audio ASR was as low as 25.5%. Whereas, the classification accuracy of the MES ASR was 85.2%. The classification accuracy could be further improved by employing the proposed audio-MES weighting method, which was as high as 89.4% in the case of babble noise. A similar result was also found for the other types of noise.

  12. Implantable digital hearing aid

    NASA Technical Reports Server (NTRS)

    Kissiah, A. M., Jr.

    1979-01-01

    Hearing aid converts analog output of microphone into digital pulses in about 10 channels of audiofrequencies. Each pulse band could be directly connected to portion of auditory nerve most sensitive to that range.

  13. The multipath and SNR Quality in civil code L2

    NASA Astrophysics Data System (ADS)

    Polezel, W. G.; Souza, E. M.; Monico, J. F.

    2007-12-01

    The new generation of GPS satellites, with the addition of the new L2C civil code, may provide to the users better positioning capabilities. The new code in the L2 may increase the signal robustness, improve resistance to interference, reduce tracking noise and consequently, improve accuracy and provide better positioning inside buildings and in wooded areas. The second civil frequency code will eliminate the need of using fragile semi- codeless tracking techniques currently used in connection with L2. The L2C has a different structure that allows civil and military share the same code. L2C owns two codes of different length: moderate code (CM) and long code (CL). The CM was chosen to have 10.230 chips repeated to every 20 millisecond. The CL was chosen to have 767250 chips with period of 1.5 second. The main reasons for these choices were due to excellent correlation properties. Furthermore, L2C enhances performance by having no data modulation on CL code, which improves, among others, the threshold tracking performance. Comparing the L2C acquisition with the C/A, the CM code is ten times longer than the C/A and the two components have half the total power. This is an important feature for many low-power applications. Although this signal has several advantages, some investigations about its performance are necessary, mainly about the provided accuracy under some effects, for example, multipath. Thus, this paper aims to analyze the L2C signal, as well as its quality using some parameters, such as Signal to Noise Ratio (SNR) and multipath level (MP). The experiment was realized at Sao Paulo State University UNESP in Presidente Prudente, Brazil. The data were collected by two receivers of different brands, both able to collect the L2C signal, and connected to the same antenna, thought the use of a splitter. The results showed that the MP and SNR values were better for the modernized satellites. Furthermore, the SNR values of the two receivers were similar while the

  14. Shocked Molecular Gas in the SNR 3C391

    NASA Astrophysics Data System (ADS)

    Bock, D. C.-J.; Wright, M. C. H.; Frail, D. A.; Gaensler, B. M.; Wilner, D. J.

    1999-05-01

    The discovery of OH (1720 MHz) masers in supernova remnants (SNRs) provides us with a convenient method for identifying promising candidates for studies of SNR/molecular cloud interactions. One remnant which is an ideal subject is 3C391. Here, single dish observations reveal a myriad of molecular lines from a giant shocked cloud at the blast-wave of the remnant. We present recent millimeter-wave observations of 3C391 with the Berkeley-Illinois-Maryland Association (BIMA) array. We have imaged the region towards the OH maser in HCN (J=1--0) and HCO+ (J=1--0) at a resolution of 4 arcsec. The morphology and brightness of the emission in HCO+ and HCN are similar; we resolve the shocked cloud seen by Frail and Mitchell (1998) into several clumps of characteristic size 10 arcsec. The maser is midway between two of these clumps, rather than being coincident with the peak column density. The clumps all have similar spectra with line-widths of ~ 30 km s(-1) , although there is evidence for a velocity gradient between the clumps. We examine the physical conditions of the shocked environment and discuss the relative abundances of the molecules. A companion study of the interaction between the SNR W51C and an associated molecular cloud is underway.

  15. Suzaku observations of SNR1987A - a rusty remnent?

    NASA Astrophysics Data System (ADS)

    Hasinger, G.; Itoh, M.; Bamba, A.; Terada, Y.; Mori, K.; Kenzaki, K.; Suzaku Snr1987A Observation Team

    We report results of Suzaku observations of SNR1987A focused on the XIS data The observations were made on November 4 2005 day 6829 after the explosion The spectrum is described with two-component thermal emission models The temperatures of the two components are sim 0 3 keV and sim 2 7 keV respectively The X-ray flux in 0 5-2 keV band was 2 28 pm 0 06 times 10 -12 erg cm -2 s -1 which follows the exponential rise with the time scale of sim 800 days since day sim 4000 after the explosion Assuming that the two components have the same elemental abundances deficiency of O and Fe was observed while the abundances of N Si and S showed higher values than the average of the LMC One of the possible interpretations of the deficiency of O and Fe is that these elements are confined in dust grains

  16. SNR and Contrast Enhancement Techniques for the Photoacoustic Radar Imaging

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Mandelis, Andreas

    2016-07-01

    This paper presents two methods for photoacoustic signal enhancement in biological tissues. One such method is based on the fact that temperature can affect the signals of the photoacoustic radar. Therefore, thermally assisted methods have been used for photoacoustic imaging contrast improvement. Another method is based on harmonic wavelength modulation which results in a differential PA radar signal to strengthen early cancer detection. Two chirped waveforms modulated out-of-phase between 680 nm and 800 nm can effectively suppress the background noise, greatly enhance the SNR and detect small variations in hemoglobin oxygenation levels, thereby distinguishing pre-malignant tumors. Experimental results demonstrate the accuracy of the frequency-modulated differential measurement with sheep blood at different hemoglobin oxygenation (S_tO2) levels.

  17. Recent developments on the SNR-CR connection

    NASA Astrophysics Data System (ADS)

    Amato, Elena

    2016-06-01

    The last few years have been rich of progress both for the science of Supernova Remnants and for Cosmic Rays. We have learnt from X-ray observations of SNRs that they host multi-TeV electrons and amplified magnetic fields, likely hints of efficient CR acceleration. We have seen gamma-ray emission from SNRs and gathered direct evidence of the presence of relativistic hadrons at least in a couple of these sources. Finally we have learnt how to properly use optical emission lines as a diagnostic of efficient CR acceleration in SNRs. On the CR side, direct experiments have shown the first clear evidence of structure in the spectra of protons and He nuclei below the knee, and in the meantime very recent measurements cast doubt about the position of the protons' knee. After briefly reviewing these recent developments, I will discuss whether and how they fit within the current theoretical framework of the SNR-CR connection.

  18. Using the GPS SNR Technique to Detect Volcanic Plumes

    NASA Astrophysics Data System (ADS)

    Naik, S. R.; Mattia, M.; Larson, K. M.; Rossi, M.; Bruno, V.; Coltelli, M.; Ohta, Y.; Schneider, D. J.

    2015-12-01

    Detection of volcanic plumes, especially ash-laden ones, is important both for public health and aircraft safety. A variety of geophysical tools and satellite data are used to monitor volcanic eruptions and to predict the movement of ash. However, satellite-based methods are restricted by time of day and weather, while radars are often unavailable because of cost/ portability. GPS instruments are frequently deployed near volcanos, but typically they have only been used to measure deformation. Here a method is proposed to detect volcanic plumes using GPS signal to noise ratio (SNR) data. The strengths and limitations of the method are assessed using GPS data collected during eruptions at Mt. Redoubt (2009) and Mt. Etna (2013). Plume detections are compared with independently collected seismic and radar data.

  19. An SNR improvement of passive SAW tags with 5-bit Barker code sequence

    NASA Astrophysics Data System (ADS)

    Bae, Hyunchul; Kim, Jaekwon; Burm, Jinwook

    2012-07-01

    Passive surface acoustic wave (SAW) tags require a large signal-to-noise ratio (SNR) in order to increase the interrogation range. For the purpose of achieving high SNR for radio frequency identification (RFID) communication systems, Barker codes, a binary phase shift keying (BPSK) modulation technique, have been adopted in this study. Passive SAW RFID tags were designed with 5-bit Barker code sequences to generate BPSK modulated signals. Through the SNR analysis, the improvements in SNR were about 11 dB using Barker codes along with a correlator, which can be further improved by optimisation in the correlator.

  20. Carrier tracking by smoothing filter can improve symbol SNR

    NASA Technical Reports Server (NTRS)

    Hurd, W. J.; Pomalaza-Raez, C. A.

    1985-01-01

    The potential benefit of using a smoothing filter to estimate carrier phase over use of phase locked loops (PLL) is determined. Numerical results are presented for the performance of three possible configurations of the deep space network advanced receiver. These are residual carrier PLL, sideband aided residual carrier PLL, and finally sideband aiding with a Kalman smoother. The average symbol signal to noise ratio (CNR) after losses due to carrier phase estimation error is computed for different total power SNRs, symbol rates and symbol SNRs. It is found that smoothing is most beneficial for low symbol SNRs and low symbol rates. Smoothing gains up to 0.4 dB over a sideband aided residual carrier PLL, and the combined benefit of smoothing and sideband aiding relative to a residual carrier loop is often in excess of 1 dB.

  1. SNR 1987A: the birth of a Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Bouchet, Patrice; Danziger, John

    Observations show that the infrared emission from dust observed in Supernovae and Supernova Remants originates both from the freshly synthesized dust in the expanding envelope and from pre-existing dust in the CSM. There are some few cases where it is suggested that dust formed recently in the CSM as a result of interaction with the expanding emvelope. The mass of dust in these various environments is, with a few exceptions, poorly determined. However the few estimates of the dust mass condensed in the ejecta make questionable so far any claims for supernovae being significant dust factories. This is the case in particular for SNR 1987A. We present up to date multiwavelength observations of this incipient remnant obtained with the VLT, Gemini, Chandra, Hubble and Spitzer Space Telescope. The various light curves show that the morphology and luminosity of the remnant are rapidly changing at X-ray, optical, and infrared wavelengths as the blast wave from the explosion expands into the circumstellar equatorial ring produced by mass loss from the progenitor 20000 years before the explosion. The observed IR/soft-X-ray flux ratio (IRX) is consistent with that of a dusty plasma with standard LMC dust abundances. This ratio decreased between days 6190 and 7137, providing the first direct observation of dust destruction, and has been remarkably stable since that date (up to day 8000), which might indicate that the episode of destruction has terminated. We show that the main components of the dust grains present in the ring are silicates and a model consistent with the observations has been elaborated. There remain some spectral features which are not explained. In addition, the lack of a strong correlation between images obtained in the visible (hot spots) and in the mid-infrared (dust clumps) also makes the precise location of the soft X-ray emitting region uncertain. The composition of the grains that have condensed in the ejecta of SN 1987A is still not known with

  2. A Charge-Based Low-Power High-SNR Capacitive Sensing Interface Circuit

    PubMed Central

    Peng, Sheng-Yu; Qureshi, Muhammad S.; Hasler, Paul E.; Basu, Arindam; Degertekin, F. L.

    2008-01-01

    This paper describes a low-power approach to capacitive sensing that achieves a high signal-to-noise ratio. The circuit is composed of a capacitive feedback charge amplifier and a charge adaptation circuit. Without the adaptation circuit, the charge amplifier only consumes 1 μW to achieve the audio band SNR of 69.34dB. An adaptation scheme using Fowler-Nordheim tunneling and channel hot electron injection mechanisms to stabilize the DC output voltage is demonstrated. This scheme provides a very low frequency pole at 0.2Hz. The measured noise spectrums show that this slow-time scale adaptation does not degrade the circuit performance. The DC path can also be provided by a large feedback resistance without causing extra power consumption. A charge amplifier with a MOS-bipolar pseudo-resistor feedback scheme is interfaced with a capacitive micromachined ultrasonic transducer to demonstrate the feasibility of this approach for ultrasound applications. PMID:18787650

  3. SNR bounds of FSO links and its evaluation for selected beams

    NASA Astrophysics Data System (ADS)

    Eyyuboğlu, Halil T.; Bayraktar, Mert

    2015-09-01

    We formulate the signal-to-noise ratio (SNR) for free-space optical links. Upon inserting typical operating parameters, it is seen that SNR well approximates to the inverse of aperture averaged scintillation parameter. By adopting a common source beam power of 10 mW, we select three different source sizes of Gaussian, annular Gaussian (AG), and cosh-Gaussian beams. We then evaluate the SNR of these beams. Our results indicate that when fixed aperture opening is used, fully and partially coherent beams yield almost the same SNR performance. On the other hand, however, focusing and lowering wavelength of operation appear to be quite instrumental in improving the SNR performance. In this context, medium-sized AGB seems to exhibit the best performance.

  4. Ergogenic aids.

    PubMed

    Coyle, E F

    1984-07-01

    The catabolism of bodily fuels provides the energy for muscular work. Work output can be limited by the size of fuel reserves, the rate of their catabolism, the build-up of by-products, or the neurologic activation of muscle. A substance that favorably affects a step that is normally limiting, and thus increases work output, can be considered an ergogenic aid. The maximal amount of muscular force generated during brief contractions can be acutely increased during hypnosis and with the ingestion of a placebo or psychomotor stimulant. This effect is most obvious in subjects under laboratory conditions and is less evident in athletes who are highly motivated prior to competition. Fatigue is associated with acidosis in the working musculature when attempts are made to maximize work output during a 4 to 15-minute period. Sodium bicarbonate ingestion may act to buffer the acid produced, provided that blood flow to the muscle is adequate. Prolonged intense exercise can be maintained for approximately two hours before carbohydrate stores become depleted. Carbohydrate feedings delay fatigue during prolonged exercise, especially in subjects who display a decline in blood glucose during exercise in the fasting state. Caffeine ingestion prior to an endurance bout has been reported to allow an individual to exercise somewhat more intensely than he or she would otherwise. Its effect may be mediated by augmenting fat metabolism or by altering the perception of effort. Amphetamines may act in a similar manner. Water ingestion during prolonged exercise that results in dehydration and hyperthermia can offset fluid losses and allow an individual to better maintain work output while substantially reducing the risk of heat-related injuries. PMID:6100848

  5. Development of output signal-to-noise ratio tester for microchannel plate and fluorescent screen component

    NASA Astrophysics Data System (ADS)

    Wu, Xinglin; Qiu, Yafeng; Zhou, Jin; Qian, Yunsheng

    The core components of Image intensifier is microchannel plate (MCP) and fluorescent screen component. The present paper deeply studies output signal-to-noise ratio (SNR) characteristics of MCP and fluorescent screen component. A tester system using to the evaluation of characteristics of the output SNR of MCP and fluorescent screen component, consists of a vacuum system, a surface electron source, mechanical mechanism components ,a high-voltage power supply system, a signal processing system, communication interfaces, a data acquisition and control system, computer system, and testing software. a hot cathode used as an electron source, generates a surface electron flow to provide the input signal. A photomultiplier tube is used to detection faceplate output brightness of the light spot. Then, the output SNR of MCP and fluorescent screen component is processed with a combination of methods of the hardware filter and digital filtering software. The output SNR of MCP and fluorescent screen component is measured under different conditions, and the results are analyzed. This test system Provide a technical to promote the image intensifier research, and experience to testing other parameters or in other areas of research.

  6. An octahedral shear strain-based measure of SNR for 3D MR elastography

    NASA Astrophysics Data System (ADS)

    McGarry, M. D. J.; Van Houten, E. E. W.; Perriñez, P. R.; Pattison, A. J.; Weaver, J. B.; Paulsen, K. D.

    2011-07-01

    A signal-to-noise ratio (SNR) measure based on the octahedral shear strain (the maximum shear strain in any plane for a 3D state of strain) is presented for magnetic resonance elastography (MRE), where motion-based SNR measures are commonly used. The shear strain, γ, is directly related to the shear modulus, μ, through the definition of shear stress, τ = μγ. Therefore, noise in the strain is the important factor in determining the quality of motion data, rather than the noise in the motion. Motion and strain SNR measures were found to be correlated for MRE of gelatin phantoms and the human breast. Analysis of the stiffness distributions of phantoms reconstructed from the measured motion data revealed a threshold for both strain and motion SNR where MRE stiffness estimates match independent mechanical testing. MRE of the feline brain showed significantly less correlation between the two SNR measures. The strain SNR measure had a threshold above which the reconstructed stiffness values were consistent between cases, whereas the motion SNR measure did not provide a useful threshold, primarily due to rigid body motion effects.

  7. Optimal filters - A unified approach for SNR and PCE. [Peak-To-Correlation-Energy

    NASA Technical Reports Server (NTRS)

    Juday, Richard D.

    1993-01-01

    A unified approach for a general metric that encompasses both the signal-to-noise ratio (SNR) and the peak-to-correlation (PCE) ratio in optical correlators is described. In this approach, the connection between optimizing SNR and optimizing PCE is achieved by considering a metric in which the central correlation irradiance is divided by the total energy of the correlation plane. The peak-to-total energy (PTE) is shown to be optimized similarly to SNR and PCE. Since PTE is a function of the search values G and beta, the optimal filter is determined with only a two-dimensional search.

  8. Music and Hearing Aids

    PubMed Central

    Moore, Brian C. J.

    2014-01-01

    The signal processing and fitting methods used for hearing aids have mainly been designed to optimize the intelligibility of speech. Little attention has been paid to the effectiveness of hearing aids for listening to music. Perhaps as a consequence, many hearing-aid users complain that they are not satisfied with their hearing aids when listening to music. This issue inspired the Internet-based survey presented here. The survey was designed to identify the nature and prevalence of problems associated with listening to live and reproduced music with hearing aids. Responses from 523 hearing-aid users to 21 multiple-choice questions are presented and analyzed, and the relationships between responses to questions regarding music and questions concerned with information about the respondents, their hearing aids, and their hearing loss are described. Large proportions of the respondents reported that they found their hearing aids to be helpful for listening to both live and reproduced music, although less so for the former. The survey also identified problems such as distortion, acoustic feedback, insufficient or excessive gain, unbalanced frequency response, and reduced tone quality. The results indicate that the enjoyment of listening to music with hearing aids could be improved by an increase of the input and output dynamic range, extension of the low-frequency response, and improvement of feedback cancellation and automatic gain control systems. PMID:25361601

  9. Music and hearing aids.

    PubMed

    Madsen, Sara M K; Moore, Brian C J

    2014-10-31

    The signal processing and fitting methods used for hearing aids have mainly been designed to optimize the intelligibility of speech. Little attention has been paid to the effectiveness of hearing aids for listening to music. Perhaps as a consequence, many hearing-aid users complain that they are not satisfied with their hearing aids when listening to music. This issue inspired the Internet-based survey presented here. The survey was designed to identify the nature and prevalence of problems associated with listening to live and reproduced music with hearing aids. Responses from 523 hearing-aid users to 21 multiple-choice questions are presented and analyzed, and the relationships between responses to questions regarding music and questions concerned with information about the respondents, their hearing aids, and their hearing loss are described. Large proportions of the respondents reported that they found their hearing aids to be helpful for listening to both live and reproduced music, although less so for the former. The survey also identified problems such as distortion, acoustic feedback, insufficient or excessive gain, unbalanced frequency response, and reduced tone quality. The results indicate that the enjoyment of listening to music with hearing aids could be improved by an increase of the input and output dynamic range, extension of the low-frequency response, and improvement of feedback cancellation and automatic gain control systems.

  10. Music and hearing aids.

    PubMed

    Madsen, Sara M K; Moore, Brian C J

    2014-01-01

    The signal processing and fitting methods used for hearing aids have mainly been designed to optimize the intelligibility of speech. Little attention has been paid to the effectiveness of hearing aids for listening to music. Perhaps as a consequence, many hearing-aid users complain that they are not satisfied with their hearing aids when listening to music. This issue inspired the Internet-based survey presented here. The survey was designed to identify the nature and prevalence of problems associated with listening to live and reproduced music with hearing aids. Responses from 523 hearing-aid users to 21 multiple-choice questions are presented and analyzed, and the relationships between responses to questions regarding music and questions concerned with information about the respondents, their hearing aids, and their hearing loss are described. Large proportions of the respondents reported that they found their hearing aids to be helpful for listening to both live and reproduced music, although less so for the former. The survey also identified problems such as distortion, acoustic feedback, insufficient or excessive gain, unbalanced frequency response, and reduced tone quality. The results indicate that the enjoyment of listening to music with hearing aids could be improved by an increase of the input and output dynamic range, extension of the low-frequency response, and improvement of feedback cancellation and automatic gain control systems. PMID:25361601

  11. [Analysis of the effect of detector's operating temperature on SNR in space-based remote sensor].

    PubMed

    Li, Zhan-feng; Wang, Shu-rong; Huang, Yu

    2012-03-01

    Limb viewing is a new viewing geometry for space-based atmospheric remote sensing, but the spectral radiance of atmosphere scattering reduces rapidly with limb height. So the signal-noise-ratio (SNR) is a key performance parameter of limb remote sensor. A SNR model varying with detector's temperature is proposed, based on analysis of spectral radiative transfer and noise' source in representative instruments. The SNR at limb height 70 km under space conditions was validated by simulation experiment on limb remote sensing spectrometer prototype. Theoretic analysis and experiment's results indicate congruously that when detector's temperature reduces to some extent, a maximum SNR will be reached. After considering the power consumption, thermal conductivity and other issues, optimal operating temperature of detector can be decided.

  12. Spatially Resolved Spectroscopy of the SNR IC443

    NASA Astrophysics Data System (ADS)

    Gorenstein, P.

    1998-07-01

    IC 443 is a supernova remnant of intermediate age, i.e. a few thousand years. It is especially interesting because part of its periphery is expanding into a molecular cloud while other sections are expanding into a typical interstellar medium of much lower density. Since the evolution of a supernova remnant through its various phases is affected by the density of the medium it expands into with the reasonable assumption that the supernova explosion was approximately symmetric we have an opportunity to observe a single object in two phases simultaneously. It was observed by ASCA in April, 1993 for a short period during the PV phase and more thoroughly in a 42 ksec exposure in March, 1994. The latter measurement provides most of the results that have been reported. Most of the analysis took place after the grant ended but is included here for completeness. The data was sent simultaneously to US and Japanese Pls. We worked independently. The software set of FTOOLs was used to construct images and spectra. They were judged to be rather unintuitive and not at all user friendly. I found I was using one FTOOL to read the header to obtain information that would only be provided to another FTOOL. The Japanese investigators were more successful. They analyzed the data and published results more rapidly. The scientific results summarized below are based primarily on their publications. Since IC 443 is an interesting example of a middle aged SNR in which a variety of processes are occurring it is one of a class. IC 443 exhibits shell-like emission in hard X-rays and extended soft X-rays with thin thermal spectra. It resembles SN 1006 in these respects. IC 443 contains hard X-rays in a semi-circular shell surrounding the thermal component. The total hard X-ray flux in the ASCA FOV is only a half of the Ginga hard component; which suggests that the hard X-rays are not confined only in the shell but some are extended larger than the ASCA FOV of eq 1 degree diameter. Japanese

  13. Spatially Resolved Spectroscopy of the SNR IC443

    NASA Technical Reports Server (NTRS)

    Gorenstein, P.

    1998-01-01

    IC 443 is a supernova remnant of intermediate age, i.e. a few thousand years. It is especially interesting because part of its periphery is expanding into a molecular cloud while other sections are expanding into a typical interstellar medium of much lower density. Since the evolution of a supernova remnant through its various phases is affected by the density of the medium it expands into with the reasonable assumption that the supernova explosion was approximately symmetric we have an opportunity to observe a single object in two phases simultaneously. It was observed by ASCA in April, 1993 for a short period during the PV phase and more thoroughly in a 42 ksec exposure in March, 1994. The latter measurement provides most of the results that have been reported. Most of the analysis took place after the grant ended but is included here for completeness. The data was sent simultaneously to US and Japanese Pls. We worked independently. The software set of FTOOLs was used to construct images and spectra. They were judged to be rather unintuitive and not at all user friendly. I found I was using one FTOOL to read the header to obtain information that would only be provided to another FTOOL. The Japanese investigators were more successful. They analyzed the data and published results more rapidly. The scientific results summarized below are based primarily on their publications. Since IC 443 is an interesting example of a middle aged SNR in which a variety of processes are occurring it is one of a class. IC 443 exhibits shell-like emission in hard X-rays and extended soft X-rays with thin thermal spectra. It resembles SN 1006 in these respects. IC 443 contains hard X-rays in a semi-circular shell surrounding the thermal component. The total hard X-ray flux in the ASCA FOV is only a half of the Ginga hard component; which suggests that the hard X-rays are not confined only in the shell but some are extended larger than the ASCA FOV of eq 1 degree diameter. Japanese

  14. HIV / AIDS

    MedlinePlus

    ... Marketing Share this: Main Content Area Understanding HIV/AIDS AIDS was first reported in the United States in ... and has since become a major worldwide epidemic. AIDS is caused by the human immunodeficiency virus, or ...

  15. Multiple Output Sensory Trainer (MOST). Final Report.

    ERIC Educational Resources Information Center

    Automated Functions, Inc., Arlington, VA.

    This final report describes the design, development, and testing of the Multiple Output Sensory Trainer (MOST), a computer-based system which enables the evaluation of students with visual impairments to determine the optimal combination of sensory adaptive aids to meet their needs. The system uses multimedia devices in conjunction with customized…

  16. The upper limits of the SNR in radiography and CT with polyenergetic x-rays.

    PubMed

    Shikhaliev, Polad M

    2010-09-21

    The aim of the study is to determine the upper limits of the signal-to-noise ratio (SNR) in radiography and computed tomography (CT) with polyenergetic x-ray sources. In x-ray imaging, monoenergetic x-rays provide a higher SNR compared to polyenergetic x-rays. However, the SNR in polyenergetic x-ray imaging can be increased when a photon-counting detector is used and x-rays are optimally weighted according to their energies. For a particular contrast/background combination and at a fixed x-ray entrance skin exposure, the SNR in energy-weighting x-ray imaging depends on tube voltage and can be maximized by selecting the optimal tube voltage. The SNR in energy-weighted x-ray images acquired at this optimal tube voltage is the highest SNR that can be achieved with polyenergetic x-ray sources. The optimal tube voltages and the highest SNR were calculated and compared to the SNR of monoenergetic x-ray imaging. Monoenergetic, energy-weighting polyenergetic and energy-integrating polyenergetic x-ray imagings were simulated at a fixed entrance skin exposure of 20 mR. The tube voltages varied in the range of 30-140 kVp with 10 kV steps. Contrast elements of CaCO(3), iodine, adipose and tumor with thicknesses of 280 mg cm(-2), 15 mg cm(-2), 1 g cm(-2) and 1 g cm(-2), respectively, inserted in a soft tissue background with 10 cm and 20 cm thicknesses, were used. The energy weighting also improves the contrast-to-noise ratio (CNR) in CT when monoenergetic CT projections are optimally weighted prior to CT reconstruction (projection-based weighting). Alternatively, monoenergetic CT images are reconstructed, optimally weighted and composed to yield a final CT image (image-based weighting). Both projection-based and image-based weighting methods improve the CNR in CT. An analytical approach was used to determine which of these two weighting methods provides the upper limit of the CNR in CT. The energy-weighting method was generalized and expanded as a weighting method applicable

  17. Influence of range-gated intensifiers on underwater imaging system SNR

    NASA Astrophysics Data System (ADS)

    Wang, Xia; Hu, Ling; Zhi, Qiang; Chen, Zhen-yue; Jin, Wei-qi

    2013-08-01

    Range-gated technology has been a hot research field in recent years due to its high effective back scattering eliminating. As a result, it can enhance the contrast between a target and its background and extent the working distance of the imaging system. The underwater imaging system is required to have the ability to image in low light level conditions, as well as the ability to eliminate the back scattering effect, which means that the receiver has to be high-speed external trigger function, high resolution, high sensitivity, low noise, higher gain dynamic range. When it comes to an intensifier, the noise characteristics directly restrict the observation effect and range of the imaging system. The background noise may decrease the image contrast and sharpness, even covering the signal making it impossible to recognize the target. So it is quite important to investigate the noise characteristics of intensifiers. SNR is an important parameter reflecting the noise features of a system. Through the use of underwater laser range-gated imaging prediction model, and according to the linear SNR system theory, the gated imaging noise performance of the present market adopted super second generation and generation Ⅲ intensifiers were theoretically analyzed. Based on the active laser underwater range-gated imaging model, the effect to the system by gated intensifiers and the relationship between the system SNR and MTF were studied. Through theoretical and simulation analysis to the image intensifier background noise and SNR, the different influence on system SNR by super second generation and generation Ⅲ ICCD was obtained. Range-gated system SNR formula was put forward, and compared the different effect influence on the system by using two kind of ICCDs was compared. According to the matlab simulation, a detailed analysis was carried out theoretically. All the work in this paper lays a theoretical foundation to further eliminating back scattering effect, improving

  18. Hot Gas in SMC SNR 0057-7226 and the Giant H 2 Region N66

    NASA Astrophysics Data System (ADS)

    Danforth, C. W.; Hoopes, C. G.; Sankrit, R.; Chu, Y.-H.; Sembach, K. R.; Blair, W. P.

    2001-12-01

    The supernova remnant SNR 0057-7226 and the dense, young cluster NGC 346 lie within the giant H 2 region N66, the most active star formation site in the SMC. Far Ultraviolet Spectroscopic Explorer (FUSE) observations of the Wolf-Rayet binary system HD 5980, which lies behind the SNR, show high velocity, O 6 and C 3 absorption associated with the far side of the remnant (Hoopes et al 2001, ApJ, 558, L35). Chandra ACIS-I and ROSAT HRI images of N66 show the diffuse X-ray emission associated with the SNR, but little or no diffuse emission around the core of the central cluster. We present high-dispersion, long-slit optical echelle observations of five positions within N66 including positions across the SNR 0057-7226 and NGC 346. These data show bright Hα emission at the SMC rest velocity (v ~155 km s-1). Where the spectrograph slits intersect the SNR, faint Hα emission at high (v ~300 km s-1) and low (v ~50 km s-1) velocities reveals clumps of material on the back and front sides of the SNR shell. Ten FUSE observations of sight lines toward stars in N66--including four toward NGC 346 cluster stars--provide sensitive absorption-line measurements of several ionic species including O 6 which traces hot (T ~3*E5 K), highly-ionized gas and Fe 2 which traces cooler (T ~104 K), ionized and neutral gas. We also present ground based optical narrowband images in Hα , [S 2], and [O 3] which show the morphology of the H 2 region. We use this data set to study the kinematics of the gas in this complex region and to model the properties of the SNR-ISM interaction. This work is supported by NASA Contract NAS5-32985 to the Johns Hopkins University.

  19. Enhanced leavening ability of baker's yeast by overexpression of SNR84 with PGM2 deletion.

    PubMed

    Lin, Xue; Zhang, Cui-Ying; Bai, Xiao-Wen; Xiao, Dong-Guang

    2015-06-01

    Dough-leavening ability is one of the main aspects considered when selecting a baker's yeast strain for baking industry. Generally, modification of maltose metabolic pathway and known regulatory networks of maltose metabolism were used to increase maltose metabolism to improve leavening ability in lean dough. In this study, we focus on the effects of PGM2 (encoding for the phosphoglucomutase) and SNR84 (encoding for the H/ACA snoRNA) that are not directly related to both the maltose metabolic pathway and known regulatory networks of maltose metabolism on the leavening ability of baker's yeast in lean dough. The results show that the modifications on PGM2 and/or SNR84 are effective ways in improving leavening ability of baker's yeast in lean dough. Deletion of PGM2 decreased cellular glucose-1-phosphate and overexpression of SNR84 increased the maltose permease activity. These changes resulted in 11, 19 and 21% increases of the leavening ability for PGM2 deletion, SNR84 overexpression and SNR84 overexpression combining deleted PGM2, respectively.

  20. Is the gamma-ray emission from the SNR HESS J1731-347 leptonic dominated ?

    NASA Astrophysics Data System (ADS)

    Acero, Fabio; Renaud, Matthieu; Lemoine-Goumard, Marianne; Rousseau, Romain

    2012-07-01

    HESS J1731-347 is the first supernova remnant (SNR) that has been discovered based on TeV observation. First an unassociated source discovered in the survey of the Galactic plane by the HESS experiment, it has later been identified as a new SNR (through radio and X-rays observations) and is now the 4th object in the restricted club of SNRs with a TeV shell morphology. This new SNR shares many similarities with the brightest TeV SNR RX J1713.7-3946: comparable TeV luminosities, lack of thermal X-ray emission and the remnants from a gravitational core collapse (compact objects observed at the center). Using the spectral and morphological information derived in TeV, the GeV emission of the SNR is investigated with data from the Fermi Gamma-ray Space Telescope in order to test whether the nature of the gamma-ray emission is of leptonic (as it has been found for RX J1713.7-3946) or hadronic origin.

  1. Enhanced leavening ability of baker's yeast by overexpression of SNR84 with PGM2 deletion.

    PubMed

    Lin, Xue; Zhang, Cui-Ying; Bai, Xiao-Wen; Xiao, Dong-Guang

    2015-06-01

    Dough-leavening ability is one of the main aspects considered when selecting a baker's yeast strain for baking industry. Generally, modification of maltose metabolic pathway and known regulatory networks of maltose metabolism were used to increase maltose metabolism to improve leavening ability in lean dough. In this study, we focus on the effects of PGM2 (encoding for the phosphoglucomutase) and SNR84 (encoding for the H/ACA snoRNA) that are not directly related to both the maltose metabolic pathway and known regulatory networks of maltose metabolism on the leavening ability of baker's yeast in lean dough. The results show that the modifications on PGM2 and/or SNR84 are effective ways in improving leavening ability of baker's yeast in lean dough. Deletion of PGM2 decreased cellular glucose-1-phosphate and overexpression of SNR84 increased the maltose permease activity. These changes resulted in 11, 19 and 21% increases of the leavening ability for PGM2 deletion, SNR84 overexpression and SNR84 overexpression combining deleted PGM2, respectively. PMID:25877163

  2. SNR Wall Effect Alleviation by Generalized Detector Employed in Cognitive Radio Networks.

    PubMed

    Shbat, Modar Safir; Tuzlukov, Vyacheslav

    2015-01-01

    The most commonly used spectrum sensing techniques in cognitive radio (CR) networks, such as the energy detector (ED), matched filter (MF), and others, suffer from the noise uncertainty and signal-to-noise ratio (SNR) wall phenomenon. These detectors cannot achieve the required signal detection performance regardless of the sensing time. In this paper, we explore a signal processing scheme, namely, the generalized detector (GD) constructed based on the generalized approach to signal processing (GASP) in noise, in spectrum sensing of CR network based on antenna array with the purpose to alleviate the SNR wall problem and improve the signal detection robustness under the low SNR. The simulation results confirm our theoretical issues and effectiveness of GD implementation in CR networks based on antenna array. PMID:26151216

  3. Towards optimum demodulation of bandwidth-limited and low SNR square-wave subcarrier signals

    NASA Technical Reports Server (NTRS)

    Feria, Y.; Hurd, W.

    1995-01-01

    The optimum phase detector is presented for tracking square-wave subcarriers that have been bandwidth limited to a finite number of harmonics. The phase detector is optimum in the sense that the loop signal-to-noise ratio (SNR) is maximized and, hence, the rms phase tracking error is minimized. The optimum phase detector is easy to implement and achieves substantial improvement. Also presented are the optimum weights to combine the signals demodulated from each of the harmonics. The optimum weighting provides SNR improvement of 0.1 to 0.15 dB when the subcarrier loop SNR is low (15 dB) and the number of harmonics is high (8 to 16).

  4. SNR Wall Effect Alleviation by Generalized Detector Employed in Cognitive Radio Networks

    PubMed Central

    Shbat, Modar Safir; Tuzlukov, Vyacheslav

    2015-01-01

    The most commonly used spectrum sensing techniques in cognitive radio (CR) networks, such as the energy detector (ED), matched filter (MF), and others, suffer from the noise uncertainty and signal-to-noise ratio (SNR) wall phenomenon. These detectors cannot achieve the required signal detection performance regardless of the sensing time. In this paper, we explore a signal processing scheme, namely, the generalized detector (GD) constructed based on the generalized approach to signal processing (GASP) in noise, in spectrum sensing of CR network based on antenna array with the purpose to alleviate the SNR wall problem and improve the signal detection robustness under the low SNR. The simulation results confirm our theoretical issues and effectiveness of GD implementation in CR networks based on antenna array. PMID:26151216

  5. SNR Wall Effect Alleviation by Generalized Detector Employed in Cognitive Radio Networks.

    PubMed

    Shbat, Modar Safir; Tuzlukov, Vyacheslav

    2015-07-03

    The most commonly used spectrum sensing techniques in cognitive radio (CR) networks, such as the energy detector (ED), matched filter (MF), and others, suffer from the noise uncertainty and signal-to-noise ratio (SNR) wall phenomenon. These detectors cannot achieve the required signal detection performance regardless of the sensing time. In this paper, we explore a signal processing scheme, namely, the generalized detector (GD) constructed based on the generalized approach to signal processing (GASP) in noise, in spectrum sensing of CR network based on antenna array with the purpose to alleviate the SNR wall problem and improve the signal detection robustness under the low SNR. The simulation results confirm our theoretical issues and effectiveness of GD implementation in CR networks based on antenna array.

  6. Highly accurate SNR measurement using the covariance of two SEM images with the identical view.

    PubMed

    Oho, Eisaku; Suzuki, Kazuhiko

    2012-01-01

    Quality of an SEM image is strongly influenced by the extent of noise. As a well-known method in the field of SEM, the covariance is applied to measure the signal-to-noise ratio (SNR). This method has potential ability for highly accurate measurement of the SNR, which is hardly known until now. If the precautions discussed in this article are adopted, that method can demonstrate its real ability. These precautions are strongly related to "proper acquisition of two images with the identical view," "alignment of an aperture diaphragm," "reduction of charging phenomena," "elimination of particular noises," and "accurate focusing," As necessary, characteristics in SEM signal and noise are investigated from a few standpoints. When using the maximum performance of this measurement, SNR of many SEM images obtained in a variety of the SEM operating conditions and specimens can be measured accurately.

  7. High Velocity Gas in the Line of Sight to the Vela SNR

    NASA Technical Reports Server (NTRS)

    Nichols, Joy S.; Slavin, Jonathan D.

    2004-01-01

    One of the best objects for study of the structure, kinematics, and evolutionary status of a middle-aged supernova remnant (SNR) is the VELA SNR, due to its proximity, extensive optical filamentary structure, and an abundance of hot background stars for absorption line research. The VELA remnant is 7.3 degrees in diameter, based on x-ray imagery with ROSAT, with the pulsar nearly centered in the remnant. The western region of the remnant has much lower x-ray surface brightness than the remainder of the remnant and in fact escaped earlier detection with previous instrumentation. The remnant is believed to be about 11,000 years old.

  8. Thermally enhanced signal strength and SNR improvement of photoacoustic radar module

    PubMed Central

    Wang, Wei; Mandelis, Andreas

    2014-01-01

    A thermally enhanced method for improving photoacoustic imaging depth and signal-to-noise (SNR) ratio is presented in this paper. Experimental results showed that the maximum imaging depth increased by 20% through raising the temperature of absorbing biotissues (ex-vivo beef muscle) uniformly from 37 to 43°C, and the SNR was increased by 8%. The parameters making up the Gruneisen constant were investigated experimentally and theoretically. The studies showed that the Gruneisen constant of biotissues increases with temperature, and the results were found to be consistent with the photoacousitc radar theory. PMID:25136501

  9. AIDS (image)

    MedlinePlus

    AIDS (acquired immune deficiency syndrome) is caused by HIV (human immunodeficiency virus), and is a syndrome that ... life-threatening illnesses. There is no cure for AIDS, but treatment with antiviral medicine can suppress symptoms. ...

  10. Hearing Aids

    MedlinePlus

    ... more in both quiet and noisy situations. Hearing aids help people who have hearing loss from damage ... your doctor. There are different kinds of hearing aids. They differ by size, their placement on or ...

  11. Hearing Aids

    MedlinePlus

    ... type and degree of loss. Are there different styles of hearing aids? Styles of hearing aids Source: NIH/NIDCD Behind-the- ... the ear canal and are available in two styles. The in-the-canal (ITC) hearing aid is ...

  12. Estimators of The Magnitude-Squared Spectrum and Methods for Incorporating SNR Uncertainty.

    PubMed

    Lu, Yang; Loizou, Philipos C

    2011-07-01

    Statistical estimators of the magnitude-squared spectrum are derived based on the assumption that the magnitude-squared spectrum of the noisy speech signal can be computed as the sum of the (clean) signal and noise magnitude-squared spectra. Maximum a posterior (MAP) and minimum mean square error (MMSE) estimators are derived based on a Gaussian statistical model. The gain function of the MAP estimator was found to be identical to the gain function used in the ideal binary mask (IdBM) that is widely used in computational auditory scene analysis (CASA). As such, it was binary and assumed the value of 1 if the local SNR exceeded 0 dB, and assumed the value of 0 otherwise. By modeling the local instantaneous SNR as an F-distributed random variable, soft masking methods were derived incorporating SNR uncertainty. The soft masking method, in particular, which weighted the noisy magnitude-squared spectrum by the a priori probability that the local SNR exceeds 0 dB was shown to be identical to the Wiener gain function. Results indicated that the proposed estimators yielded significantly better speech quality than the conventional MMSE spectral power estimators, in terms of yielding lower residual noise and lower speech distortion. PMID:21886543

  13. Approaching Ultimate Intrinsic SNR in a Uniform Spherical Sample with Finite Arrays of Loop Coils

    PubMed Central

    Vaidya, Manushka V.; Sodickson, Daniel K.; Lattanzi, Riccardo

    2015-01-01

    We investigated to what degree and at what rate the ultimate intrinsic (UI) signal-to-noise ratio (SNR) may be approached using finite radiofrequency detector arrays. We used full-wave electromagnetic field simulations based on dyadic Green’s functions to compare the SNR of arrays of loops surrounding a uniform sphere with the ultimate intrinsic SNR (UISNR), for increasing numbers of elements over a range of magnetic field strengths, voxel positions, sphere sizes, and acceleration factors. We evaluated the effect of coil conductor losses and the performance of a variety of distinct geometrical arrangements such as “helmet” and “open-pole” configurations in multiple imaging planes. Our results indicate that UISNR at the center is rapidly approached with encircling arrays and performance is substantially lower near the surface, where a quadrature detection configuration tailored to voxel position is optimal. Coil noise is negligible at high field, where sample noise dominates. Central SNR for practical array configurations such as the helmet is similar to that of close-packed arrangements. The observed trends can provide physical insights to improve coil design. PMID:26097442

  14. Capacity analysis of threshold-based SNR scheduler in LTE systems

    NASA Astrophysics Data System (ADS)

    Sulyman, Ahmed Iyanda; Ahmad, Ishtiaq; Hassanein, Hossam; Alshebeili, Saleh A.

    2013-12-01

    This paper presents the capacity analysis of a threshold-based SNR scheduler in the long-term evolution (LTE) cellular systems. LTE standard has adopted multiuser OFDMA, and stipulates adjacent subcarrier groupings for mapping the physical OFDM subcarriers into resource blocks that form the basic unit of radio resource management (RRM) in LTE network. The standard however did not specify the details of the RRM algorithm to be employed, leaving this aspect for vendors to differentiate their products. Popular RRM algorithms such as round-robin (RR), proportional fairness (PF), and maximum SNR (MaxSNR), have been implemented recently as operator-selectable options on LTE base station (BS). In this paper, we present a threshold-based SNR scheduler that has the capability of modeling all of the above-mentioned algorithms and thus allows vendors to combine the separate implementations of these algorithms into one generalized scheduling algorithm, where the threshold level used at any time instant defines the scheduling discipline to be realized. We derive the capacity enhancement achievable using the proposed scheduling scheme, and also present system-level simulations to corroborate the analysis. Our analytical and simulation results indicate that the proposed algorithm models the existing ones closely at different values of the threshold. The results also demonstrate the data rate enhancements, and the level of user fairness, achievable in the network for various levels of the threshold.

  15. GROND observations of GRB 160622A/SNR RCW 103/SGR 1617-5103

    NASA Astrophysics Data System (ADS)

    Schady, P.; Kann, D. A.; Greiner, J.

    2016-06-01

    We observed the field of GRB 160622A/SNR RCW 103/SGR 1617-5103 (Swift trigger 700791; D'Ai et al., GCN #19547. ATel #9180) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla Observatory (Chile).

  16. Estimators of The Magnitude-Squared Spectrum and Methods for Incorporating SNR Uncertainty

    PubMed Central

    Lu, Yang; Loizou, Philipos C.

    2011-01-01

    Statistical estimators of the magnitude-squared spectrum are derived based on the assumption that the magnitude-squared spectrum of the noisy speech signal can be computed as the sum of the (clean) signal and noise magnitude-squared spectra. Maximum a posterior (MAP) and minimum mean square error (MMSE) estimators are derived based on a Gaussian statistical model. The gain function of the MAP estimator was found to be identical to the gain function used in the ideal binary mask (IdBM) that is widely used in computational auditory scene analysis (CASA). As such, it was binary and assumed the value of 1 if the local SNR exceeded 0 dB, and assumed the value of 0 otherwise. By modeling the local instantaneous SNR as an F-distributed random variable, soft masking methods were derived incorporating SNR uncertainty. The soft masking method, in particular, which weighted the noisy magnitude-squared spectrum by the a priori probability that the local SNR exceeds 0 dB was shown to be identical to the Wiener gain function. Results indicated that the proposed estimators yielded significantly better speech quality than the conventional MMSE spectral power estimators, in terms of yielding lower residual noise and lower speech distortion. PMID:21886543

  17. Multi-GNSS and Multi-frequency SNR Multipath Reflectometry of Snow Depth

    NASA Astrophysics Data System (ADS)

    Tabibi, S.; Geremia-Nievinski, F.; van Dam, T. M.

    2015-12-01

    Global Navigation Satellite System multipath reflectometry (GNSS-MR) uses ground-based signals of opportunity to retrieve snow depth at an intermediate space scale. This technique is based on the signal-to-noise ratio (SNR) of the simultaneously received direct (line-of-sight) and coherently ground reflected signals. In this contribution, forward and inverse modeling of SNR observations is presented for GLONASS-MR, extending GPS-MR to multiple GNSS. The coupling of the surface and antenna responses from short-delay near-grazing incidence multipath from CDMA and FDMA satellite navigation systems are simulated using an electromagnetic forward model. The inverse model is used to estimate parameter corrections responsible for observation residuals to estimate snow depth. The correlation between snow depth retrievals using GPS L2C signal and GLONASS R2-C/A signal is excellent, with r2 value of 0.990. In a related approach, dual-frequency SNR-based GNSS-MR, which is based on linear combination of SNR observables, is used to estimate snow depth. This ionospheric delay free method synthesizes longer carrier wavelengths ("widelaning" or delta-k) to isolate the direct power contribution in environmental retrievals.

  18. Governmentally amplified output volatility

    NASA Astrophysics Data System (ADS)

    Funashima, Yoshito

    2016-11-01

    Predominant government behavior is decomposed by frequency into several periodic components: updating cycles of infrastructure, Kuznets cycles, fiscal policy over business cycles, and election cycles. Little is known, however, about the theoretical impact of such cyclical behavior in public finance on output fluctuations. Based on a standard neoclassical growth model, this study intends to examine the frequency at which public investment cycles are relevant to output fluctuations. We find an inverted U-shaped relationship between output volatility and length of cycle in public investment. This implies that periodic behavior in public investment at a certain frequency range can cause aggravated output resonance. Moreover, we present an empirical analysis to test the theoretical implication, using the U.S. data in the period from 1968 to 2015. The empirical results suggest that such resonance phenomena change from low to high frequency.

  19. A new SNR with TeV shell-type morphology: HESS J1731-347

    NASA Astrophysics Data System (ADS)

    H.E.S.S. Collaboration; Abramowski, A.; Acero, F.; Aharonian, F.; Akhperjanian, A. G.; Anton, G.; Balzer, A.; Barnacka, A.; Barres de Almeida, U.; Becherini, Y.; Becker, J.; Behera, B.; Bernlöhr, K.; Bochow, A.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Büsching, I.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Charbonnier, A.; Chaves, R. C. G.; Cheesebrough, A.; Chounet, L.-M.; Clapson, A. C.; Coignet, G.; Cologna, G.; Conrad, J.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; Drury, L. O'C.; Dubois, F.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Egberts, K.; Eger, P.; Espigat, P.; Fallon, L.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gallant, Y. A.; Gast, H.; Gérard, L.; Gerbig, D.; Giebels, B.; Glicenstein, J. F.; Glück, B.; Goret, P.; Göring, D.; Häffner, S.; Hague, J. D.; Hampf, D.; Hauser, M.; Heinz, S.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hinton, J. A.; Hoffmann, A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; de Jager, O. C.; Jahn, C.; Jamrozy, M.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Keogh, D.; Khangulyan, D.; Khélifi, B.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Komin, Nu.; Kosack, K.; Kossakowski, R.; Laffon, H.; Lamanna, G.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Masbou, J.; Maurin, D.; Maxted, N.; McComb, T. J. L.; Medina, M. C.; Méhault, J.; Moderski, R.; Moulin, E.; Naumann, C. L.; Naumann-Godo, M.; de Naurois, M.; Nedbal, D.; Nekrassov, D.; Nguyen, N.; Nicholas, B.; Niemiec, J.; Nolan, S. J.; Ohm, S.; de Oña Wilhelmi, D.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Paz Arribas, M.; Pedaletti, G.; Pelletier, G.; Petrucci, P.-O.; Pita, S.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raue, M.; Rayner, S. M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Ripken, J.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Ruppel, J.; Ryde, F.; Sahakian, V.; Santangelo, A.; Schlickeiser, R.; Schöck, F. M.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sikora, M.; Skilton, J. L.; Sol, H.; Spengler, G.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Terrier, R.; Tluczykont, M.; Valerius, K.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Vialle, J. P.; Viana, A.; Vincent, P.; Völk, H. J.; Volpe, F.; Vorobiov, S.; Vorster, M.; Wagner, S. J.; Ward, M.; White, R.; Wierzcholska, A.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

    2011-07-01

    Aims: The recent discovery of the radio shell-type supernova remnant (SNR), G353.6-0.7, in spatial coincidence with the unidentified TeV source HESS J1731-347 has motivated further observations of the source with the High Energy Stereoscopic System (HESS) Cherenkov telescope array to test a possible association of the γ-ray emission with the SNR. Methods: With a total of 59 h of observation, representing about four times the initial exposure available in the discovery paper of HESS J1731-347, the γ-ray morphology is investigated and compared with the radio morphology. An estimate of the distance is derived by comparing the interstellar absorption derived from X-rays and the one obtained from 12CO and HI observations. Results: The deeper γ-ray observation of the source has revealed a large shell-type structure with similar position and extension (r ~ 0.25°) as the radio SNR, thus confirming their association. By accounting for the HESS angular resolution and projection effects within a simple shell model, the radial profile is compatible with a thin, spatially unresolved, rim. Together with RX J1713.7-3946, RX J0852.0-4622 and SN 1006, HESS J1731-347 is now the fourth SNR with a significant shell morphology at TeV energies. The derived lower limit on the distance of the SNR of 3.2 kpc is used together with radio and X-ray data to discuss the possible origin of the γ-ray emission, either via inverse Compton scattering of electrons or the decay of neutral pions resulting from proton-proton interaction.

  20. Type Ia SNR N103B: structure of the remnant and properties of the progenitor

    NASA Astrophysics Data System (ADS)

    Li, C.-J.; Chu, Y.-H.; Gruendl, R.; et al.

    2016-06-01

    N103B is a Type Ia supernova remnant (SNR) projected in the outskirt of the superbubble around the rich cluster NGC 1850 in the Large Magellanic Cloud (LMC). We have obtained Hubble Space Telescope (HST) images to study the physical structure of this SNR and its underlying stellar population. We have also obtained high- and medium-dispersion spectra of the SNR to identify the shocked gas components and to determine the excitation and abundances of the gas. The HST H-alpha image of N103B shows an incomplete filamentary elliptical shell and several groups of prominent knots. Our long-slit, high-dispersion spectra show that the filamentary shell is dominated by hydrogen Balmer lines; its lack of forbidden line emission indicates that the filamentary shell results from collisionless shocks into a mostly neutral medium. In contrast, the prominent knots show large velocity widths in both H-alpha line and [N II] 6548, 6583 lines. Furthermore, the [S II] 6716/6731 ratios in the knots imply electron densities >5000 /cm^-3. These spectral properties suggest that these knots are most likely circumstellar material ejected by the progenitor before the SN explosion. Interestingly, using our high-dispersion spectra, we found that the N103B SNR is inside a slow expanding shell (V_exp ~10 km/s). This kinematically identified shell is not visible morphologically. Considering the optical and X-ray properties of N103B and the discovery of the slow expanding shell encompassing the SNR, we suggest that the progenitor of N103B is a single-degenerate binary system; furthermore, the progenitor moved through the interstellar medium roughly along the minor axis of the filamentary elliptical shell. The supernova explosion center can be approximated by the center of the elliptical shell, and used to search for the surviving companion of the supernova. We suggest possible candidates for the surviving companion and implications on its mass and evolutionary stage.

  1. Fractal dimension analysis for spike detection in low SNR extracellular signals

    NASA Astrophysics Data System (ADS)

    Salmasi, Mehrdad; Büttner, Ulrich; Glasauer, Stefan

    2016-06-01

    Objective. Many algorithms have been suggested for detection and sorting of spikes in extracellular recording. Nevertheless, it is still challenging to detect spikes in low signal-to-noise ratios (SNR). We propose a spike detection algorithm that is based on the fractal properties of extracellular signals and can detect spikes in low SNR regimes. Semi-intact spikes are low-amplitude spikes whose shapes are almost preserved. The detection of these spikes can significantly enhance the performance of multi-electrode recording systems. Approach. Semi-intact spikes are simulated by adding three noise components to a spike train: thermal noise, inter-spike noise, and spike-level noise. We show that simulated signals have fractal properties which make them proper candidates for fractal analysis. Then we use fractal dimension as the main core of our spike detection algorithm and call it fractal detector. The performance of the fractal detector is compared with three frequently used spike detectors. Main results. We demonstrate that in low SNR, the fractal detector has the best performance and results in the highest detection probability. It is shown that, in contrast to the other three detectors, the performance of the fractal detector is independent of inter-spike noise power and that variations in spike shape do not alter its performance. Finally, we use the fractal detector for spike detection in experimental data and similar to simulations, it is shown that the fractal detector has the best performance in low SNR regimes. Significance. The detection of low-amplitude spikes provides more information about the neural activity in the vicinity of the recording electrodes. Our results suggest using the fractal detector as a reliable and robust method for detecting semi-intact spikes in low SNR extracellular signals.

  2. Hearing aid malfunction detection system

    NASA Technical Reports Server (NTRS)

    Kessinger, R. L. (Inventor)

    1977-01-01

    A malfunction detection system for detecting malfunctions in electrical signal processing circuits is disclosed. Malfunctions of a hearing aid in the form of frequency distortion and/or inadequate amplification by the hearing aid amplifier, as well as weakening of the hearing aid power supply are detectable. A test signal is generated and a timed switching circuit periodically applies the test signal to the input of the hearing aid amplifier in place of the input signal from the microphone. The resulting amplifier output is compared with the input test signal used as a reference signal. The hearing aid battery voltage is also periodically compared to a reference voltage. Deviations from the references beyond preset limits cause a warning system to operate.

  3. A Novel Speed Compensation Method for ISAR Imaging with Low SNR

    PubMed Central

    Liu, Yongxiang; Zhang, Shuanghui; Zhu, Dekang; Li, Xiang

    2015-01-01

    In this paper, two novel speed compensation algorithms for ISAR imaging under a low signal-to-noise ratio (SNR) condition have been proposed, which are based on the cubic phase function (CPF) and the integrated cubic phase function (ICPF), respectively. These two algorithms can estimate the speed of the target from the wideband radar echo directly, which breaks the limitation of speed measuring in a radar system. With the utilization of non-coherent accumulation, the ICPF-based speed compensation algorithm is robust to noise and can meet the requirement of speed compensation for ISAR imaging under a low SNR condition. Moreover, a fast searching implementation strategy, which consists of coarse search and precise search, has been introduced to decrease the computational burden of speed compensation based on CPF and ICPF. Experimental results based on radar data validate the effectiveness of the proposed algorithms. PMID:26225980

  4. A Novel Speed Compensation Method for ISAR Imaging with Low SNR.

    PubMed

    Liu, Yongxiang; Zhang, Shuanghui; Zhu, Dekang; Li, Xiang

    2015-01-01

    In this paper, two novel speed compensation algorithms for ISAR imaging under a low signal-to-noise ratio (SNR) condition have been proposed, which are based on the cubic phase function (CPF) and the integrated cubic phase function (ICPF), respectively. These two algorithms can estimate the speed of the target from the wideband radar echo directly, which breaks the limitation of speed measuring in a radar system. With the utilization of non-coherent accumulation, the ICPF-based speed compensation algorithm is robust to noise and can meet the requirement of speed compensation for ISAR imaging under a low SNR condition. Moreover, a fast searching implementation strategy, which consists of coarse search and precise search, has been introduced to decrease the computational burden of speed compensation based on CPF and ICPF. Experimental results based on radar data validate the effectiveness of the proposed algorithms. PMID:26225980

  5. Rigorous comparison of the spectral SNR of FTIR and EC-QCL spectroscopy (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Childs, David T. D.; Hogg, Richard A.; Groom, Kristian M.; Revin, Dmitry G.; Rehman, Ihtesham U.; Cockburn, John W.; Matcher, Stephen J.

    2016-03-01

    FTIR spectroscopy using a thermal light source has been the dominant method for obtaining infrared spectra since the 1950's. Unfortunately the limited surface brightness and low spatial coherence of black-body radiators limits the spectral SNR in microspectroscopy and stand-off detection. Two recent innovations are addressing this problem a) FTIR instruments illuminated by high-spatial coherence broad-band supercontinuum sources and b) high spatial coherence narrow-band EC-QCL's. Here we ask whether these two approaches offer equivalent sensitivity. By noting an analogy with near-infrared optical coherence tomography we rigorously show that the high temporal coherence of the EC-QCL brings an additional, very large SNR advantage over an FTIR instrument illuminated by a supercontinuum source under otherwise matched conditions. Specifically if a spectrum containing N points is recorded by both instruments using the same illumination intensity and the same detector noise level, then the EC-QCL can deliver a given spectral SNR in a time xN shorter than the FTIR instrument. This factor can reach x100, potentially even x1000, in realistic applications. We exploit the analogy with OCT further by developing a mid-infrared "swept laser", using commercially available components, in which the tuning rate is much higher than in commercial EC-QCL devices. We use this swept laser to demonstrate the SNR advantage experimentally, using a custom-made EC-QCL spectrometer and PDMS polymer samples. We explore the potential upper limits on spectral acquisition rates, both from the fundamental kinetics of gain build-up in the external cavity and from likely mechanical limits on cavity tuning rates.

  6. SNR and noise measurements for medical imaging: I. A practical approach based on statistical decision theory.

    PubMed

    Tapiovaara, M J; Wagner, R F

    1993-01-01

    A method of measuring the image quality of medical imaging equipment is considered within the framework of statistical decision theory. In this approach, images are regarded as random vectors and image quality is defined in the context of the image information available for performing a specified detection or discrimination task. The approach provides a means of measuring image quality, as related to the detection of an image detail of interest, without reference to the actual physical mechanisms involved in image formation and without separate measurements of signal transfer characteristics or image noise. The measurement does not, however, consider deterministic errors in the image; they need a separate evaluation for imaging modalities where they are of concern. The detectability of an image detail can be expressed in terms of the ideal observer's signal-to-noise ratio (SNR) at the decision level. Often a good approximation to this SNR can be obtained by employing sub-optimal observers, whose performance correlates well with the performance of human observers as well. In this paper the measurement of SNR is based on implementing algorithmic realizations of specified observers and analysing their responses while actually performing a specified detection task of interest. Three observers are considered: the ideal prewhitening matched filter, the non-prewhitening matched filter, and the DC-suppressing non-prewhitening matched filter. The construction of the ideal observer requires an impractical amount of data and computing, except for the most simple imaging situations. Therefore, the utilization of sub-optimal observers is advised and their performance in detecting a specified signal is discussed. Measurement of noise and SNR has been extended to include temporally varying images and dynamic imaging systems. PMID:8426870

  7. Diodes stabilize LED output

    NASA Technical Reports Server (NTRS)

    Deters, R. A.

    1977-01-01

    Small-signal diodes are placed in series with light-emitting diodes (LED's) to stabilize LED output against temperature fluctuations. Simple inexpensive method compensates for thermal fluctuations over a broad temperature range. Requiring few components, technique is particularly useful where circuit-board space is limited.

  8. Financial Aid.

    ERIC Educational Resources Information Center

    Graves, Mary A.

    This workbook assists college and vocational school bound American Indian students in determining their financial needs and in locating sources of financial aid. A checklist helps students assess the state of their knowledge of financial programs; a glossary defines terms pertinent to the realm of financial aid (i.e., graduate study programs,…

  9. Teaching AIDS.

    ERIC Educational Resources Information Center

    Tonks, Douglas

    This book presents a curriculum to educate students about the risk of AIDS and HIV infection. The opening chapters of the book presents a discussion of: how teachers can create an environment of support for an AIDS education program; the political and educational implications of winning principal, district, and parental support for an AIDS…

  10. SNR enhancement for composite application using multiple Doppler vibrometers based laser ultrasonic propagation imager

    NASA Astrophysics Data System (ADS)

    Truong, Thanh Chung; Lee, Jung Ryul

    2016-09-01

    In recent years, the technology of using laser ultrasonic propagation imaging for damage visualization of composite structures were applied to real-world applications. Among many choices of sensor for the Ultrasonic Propagation Imager, the laser interferometry has several advantages: it is non-invasive, and portable, and with extraordinarily long-range measurement. However, the critical issue with interferometry sensing is its low signal-to-noise ratio (SNR), where the background noise can mask the damage-induced waves and making it impossible to identify the damages, especially in composite structures. In this paper, we propose a hardware-based SNR enhancement technique using multiple Laser Doppler Vibrometers (LDVs). The out-of-plane mode of ultrasonic signals are measured by multiple LDVs at a common sensing point and then averaged in real time. We showed that the SNR enhancement in experiments was consistent with the theoretical prediction, and also the test results showed a clear improvement for damage visualization of structures using Ultrasonic Wave Propagation Imaging and Ultrasonic Wavenumber Imaging algorithms.

  11. Spatial variation of SNR in two- and three dimensional neuro-PET

    SciTech Connect

    Li, H.H.; Votaw, J.R.

    1997-04-01

    A method for region of interest (ROI) evaluation for three-dimensional (3-D) positron emission tomography (PET) in the sinogram space was implemented, according to the fully 3-D filtered back-projection algorithm. With this method, the statistical error in the image that propagates from the Poisson noise in the raw data was computed. The signal-to-noise ratio (SNR) for ROI`s at various locations inside a cylindrical phantom was computed from both scanner data and simulation data and was verified via the standard deviation method through multiple measurements. As a comparison, two-dimensional (2-D) scans were also collected and similar computations carried out. Results show that the SNR increases with radius due to decreased attenuation at the edge of the phantom. For 3-D scans, the SNR drops gradually for ROI`s outside the central 8 cm of the field of view (FOV). Also, it was found that the random events must be recorded and considered in the error computation.

  12. An Atypical Neon Rich Type 1-a SNR in the SMC: an Astronomical Vegas Strip?

    NASA Astrophysics Data System (ADS)

    Roper, Quentin; McEntaffer, R. L.

    2011-01-01

    Supernova Remnant (SNR) 0104-72.3 is a highly asymmetric SNR discovered in the Small Magellanic Cloud. Its metallicity-poor environment led Hughes and Smith et al. (1994) to conclude that 0104-72.3 was formed by a Type 2 supernova. However, in a recent Chandra observation, Fe-L emission was identified in the spectrum of 0104-72.3, and, when combined with its asymmetry, led Park et al. to conclude that 0104-72.3 was formed by a Type 1-a supernova. We, through this presentation, will support the findings of Park et al., and also introduce new results in the discovery of Ne IX ejecta emission, which is inconsistent with many of the extant explosion models of Type I-a supernovae. We will discuss the atypical nature of this SNR's birth, including the possibility of a doubly-degenerate merger of C-O white dwarves, or the possibility that this was formed by accretion onto an O-Ne-Mg white dwarf.

  13. GNSS-SNR-derived water surface heights based on Newton Interval Analysis

    NASA Astrophysics Data System (ADS)

    Reinking, Jörg

    2016-04-01

    The power of Global navigation satellite system (GNSS) signals is commonly recorded as signal-to-noise ratio (SNR) by GNSS receivers. SNR mainly depends on the direct signal but also on the reflected signal. Hence the analysis of SNR data allows the computation of heights of the reflecting surfaces by means of interference pattern technique (IPT). In classical IPT the distance between the antenna and the reflector is derived from the multipath pattern using a Lomb-Scargle Periodogram (LSP) analysis which is calculated separately for every satellite involved. The final reflector height is later estimated combining all those results A more sophisticated approach uses a consistent computation of the reflector height from all observations of all satellites in a single estimation step. This is achieved by replacing LSP analysis by an appropriate common least squares adjustment for all satellites. The sum of squares of residuals from such an adjustment depends on the reflector height and is used as an objective function. The reflector height is than derived in a global optimization process based on interval analysis. This approach additionally reduces the computational efforts compared to LSP. For a constant or only slowly changing reflector height, the height could be treated at least as a quasi-static non-time-depending function for a particular time window. In this one-dimensional case the global optimization can be carried out based on the Interval Newton Method. The method is demonstrated using a data set obtain from a measurement on the Weser river, Germany.

  14. Keyboard With Voice Output

    NASA Technical Reports Server (NTRS)

    Huber, W. C.

    1986-01-01

    Voice synthesizer tells what key is about to be depressed. Verbal feedback useful for blind operators or where dim light prevents sighted operator from seeing keyboard. Also used where operator is busy observing other things while keying data into control system. Used as training aid for touch typing, and to train blind operators to use both standard and braille keyboards. Concept adapted to such equipment as typewriters, computers, calculators, telephones, cash registers, and on/off controls.

  15. Aided Electrophysiology Using Direct Audio Input: Effects of Amplification and Absolute Signal Level

    PubMed Central

    Billings, Curtis J.; Miller, Christi W.; Tremblay, Kelly L.

    2016-01-01

    Purpose This study investigated (a) the effect of amplification on cortical auditory evoked potentials (CAEPs) at different signal levels when signal-to-noise ratios (SNRs) were equated between unaided and aided conditions, and (b) the effect of absolute signal level on aided CAEPs when SNR was held constant. Method CAEPs were recorded from 13 young adults with normal hearing. A 1000-Hz pure tone was presented in unaided and aided conditions with a linear analog hearing aid. Direct audio input was used, allowing recorded hearing aid noise floor to be added to unaided conditions to equate SNRs between conditions. An additional stimulus was created through scaling the noise floor to study the effect of signal level. Results Amplification resulted in delayed N1 and P2 peak latencies relative to the unaided condition. An effect of absolute signal level (when SNR was constant) was present for aided CAEP area measures, such that larger area measures were found at higher levels. Conclusion Results of this study further demonstrate that factors in addition to SNR must also be considered before CAEPs can be used to clinically to measure aided thresholds. PMID:26953543

  16. Climate Model Output Rewriter

    SciTech Connect

    Taylor, K. E.; Doutriaux, C.

    2004-06-21

    CMOR comprises a set of FORTRAN 90 dunctions that can be used to produce CF-compliant netCDF files. The structure of the files created by CMOR and the metadata they contain fulfill the requirements of many of the climate community’s standard model experiments (which are referred to here as "MIPS", which stands for "model intercomparison project", including, for example, AMIP, CMIP, CFMIP, PMIP, APE, and IPCC scenario runs), CMOR was not designed to serve as an all-purpose wfiter of CF-compliant netCDF files, but simply to reduce the effort required to prepare and manage MIP data. Although MIPs encourage systematic analysis of results across models, this is only easy to do if the model output is written in a common format with files structured similarly and with sufficient metadata uniformly stored according to a common standard. Individual modeling groups store their data in different ways. but if a group can read its own data with FORTRAN, then it should easily be able to transform the data, using CMOR, into the common format required by the MIPs, The adoption of CMOR as a standard code for exchanging climate data will facilitate participation in MIPs because after learning how to satisfy the output requirements of one MIP, it will be easy to prepare output for the other MIPs.

  17. Climate Model Output Rewriter

    2004-06-21

    CMOR comprises a set of FORTRAN 90 dunctions that can be used to produce CF-compliant netCDF files. The structure of the files created by CMOR and the metadata they contain fulfill the requirements of many of the climate community’s standard model experiments (which are referred to here as "MIPS", which stands for "model intercomparison project", including, for example, AMIP, CMIP, CFMIP, PMIP, APE, and IPCC scenario runs), CMOR was not designed to serve as anmore » all-purpose wfiter of CF-compliant netCDF files, but simply to reduce the effort required to prepare and manage MIP data. Although MIPs encourage systematic analysis of results across models, this is only easy to do if the model output is written in a common format with files structured similarly and with sufficient metadata uniformly stored according to a common standard. Individual modeling groups store their data in different ways. but if a group can read its own data with FORTRAN, then it should easily be able to transform the data, using CMOR, into the common format required by the MIPs, The adoption of CMOR as a standard code for exchanging climate data will facilitate participation in MIPs because after learning how to satisfy the output requirements of one MIP, it will be easy to prepare output for the other MIPs.« less

  18. Hearing Aid

    MedlinePlus

    ... and Food and Drug Administration Staff FDA permits marketing of new laser-based hearing aid with potential ... feeds Follow FDA on Twitter Follow FDA on Facebook View FDA videos on YouTube View FDA photos ...

  19. Tracking performance of the polarity-type costas loop at low SNR for UQPSK signal. [Unbalanced Quadri-PSK

    NASA Technical Reports Server (NTRS)

    Park, Y. H.

    1981-01-01

    Carrier tracking performance of the polarity type costas loop is analyzed for unbalanced quadriphase-shift-keyed (UQPSK) signals at low SNR. Squaring losses for various SNR, IF bandwidth, and data rate ratios are presented. The RMS phase jitter for a particular loop is computed for various I and Q channel power and data rate ratios. Experimental results using a breadboard costas loop are also included.

  20. Fe K and ejecta emission in SNR G15.9+0.2 with XMM-Newton

    NASA Astrophysics Data System (ADS)

    Maggi, Pierre; Acero, Fabio

    2016-06-01

    We present a study of the Galactic supernova remnant SNR G15.9+0.2 with archival XMM-Newton observations. Using EPIC's collective power, we report for the first time the detection of Fe K line emission from SNR G15.9+0.2. We measure the line properties (e.g. centroid energy and width) and find evidence for spatial variations. We discuss how SNR G15.9+0.2 fits within the current sample of SNRs with detected Fe K emission and found that it is the core-collapse SNR with the lowest Fe K centroid energy. We also present some caveats to the use of Fe K line centroid energies as typing tools for SNRs. We analyse the emission-line rich X-ray spectra extracted from various regions. The abundances of Mg, Si, S, Ar, and Ca are super-solar and their ratios strongly suggests that the progenitor of SNR G15.9+0.2 was a massive star, strengthening the physical association to a candidate Central Compact Object detected with Chandra. Using the absorption column density and ambient medium density constrained by the X-ray spectral analysis, we revise the measurements of the age and distance to the SNR.

  1. Empirical Evaluation of a New Method for Calculating Signal to Noise Ratio (SNR) for Microarray Data Analysis

    SciTech Connect

    Zhou, Jizhong; He, Zhili; Zhou, Jizhong

    2008-03-06

    Signal-to-noise-ratio (SNR) thresholds for microarray data analysis were experimentally determined with an oligonucleotide array that contained perfect match (PM) and mismatch (MM) probes based upon four genes from Shewanella oneidensis MR-1. A new SNR calculation, called signal to both standard deviations ratio (SSDR) was developed, and evaluated along with other two methods, signal to standard deviation ratio (SSR), and signal to background ratio (SBR). At a low stringency, the thresholds of SSR, SBR, and SSDR were 2.5, 1.60 and 0.80 with oligonucleotide and PCR amplicon as target templates, and 2.0, 1.60 and 0.70 with genomic DNA as target templates. Slightly higher thresholds were obtained at the high stringency condition. The thresholds of SSR and SSDR decreased with an increase in the complexity of targets (e.g., target types), and the presence of background DNA, and a decrease in the composition of targets, while SBR remained unchanged under all situations. The lowest percentage of false positives (FP) and false negatives (FN) was observed with the SSDR calculation method, suggesting that it may be a better SNR calculation for more accurate determination of SNR thresholds. Positive spots identified by SNR thresholds were verified by the Student t-test, and consistent results were observed. This study provides general guidance for users to select appropriate SNR thresholds for different samples under different hybridization conditions.

  2. Reliability study of TWT output RF window

    NASA Astrophysics Data System (ADS)

    Rocci, Peter J.

    1990-05-01

    Rome Air Development Center Computer-Aided Systems Engineering Branch (RBES) has documented an in-house effort to evaluate the structural reliability of the output waveguides window on a Traveling Wave Tube (TWT). This window acts as a seal between the TWT's vacuum envelope and output waveguide. Its purpose is to prevent any loss due to leakage of the vacuum while allowing passage of the microwave signal. This particular disk-shaped window is constructed of a ceramic material, beryllia, and contains an inner ring of copper and an outer ring of Monel K-500 (70 to 30 nickle-copper). It was suspected that excessive thermal stresses associated with the very high operating temperatures by this window has caused it to fail. Finite element analyses, along with material failure theories were used to determine the window's response to a time-dependent heat source and operating heat sink temperature.

  3. Intelligibility for Binaural Speech with Discarded Low-SNR Speech Components.

    PubMed

    Schoenmaker, Esther; van de Par, Steven

    2016-01-01

    Speech intelligibility in multitalker settings improves when the target speaker is spatially separated from the interfering speakers. A factor that may contribute to this improvement is the improved detectability of target-speech components due to binaural interaction in analogy to the Binaural Masking Level Difference (BMLD). This would allow listeners to hear target speech components within specific time-frequency intervals that have a negative SNR, similar to the improvement in the detectability of a tone in noise when these contain disparate interaural difference cues. To investigate whether these negative-SNR target-speech components indeed contribute to speech intelligibility, a stimulus manipulation was performed where all target components were removed when local SNRs were smaller than a certain criterion value. It can be expected that for sufficiently high criterion values target speech components will be removed that do contribute to speech intelligibility. For spatially separated speakers, assuming that a BMLD-like detection advantage contributes to intelligibility, degradation in intelligibility is expected already at criterion values below 0 dB SNR. However, for collocated speakers it is expected that higher criterion values can be applied without impairing speech intelligibility. Results show that degradation of intelligibility for separated speakers is only seen for criterion values of 0 dB and above, indicating a negligible contribution of a BMLD-like detection advantage in multitalker settings. These results show that the spatial benefit is related to a spatial separation of speech components at positive local SNRs rather than to a BMLD-like detection improvement for speech components at negative local SNRs. PMID:27080648

  4. AIDS lymphomas.

    PubMed

    Middleton, G W; Lau, R K

    1992-01-01

    Chronically immunosuppressed individuals are susceptible to lymphoreticular tumors. Up to 15% of patients with congenital deficiencies such as ataxia=telangiectasia may develop malignancies, mainly high-grade B cell non=Hodgkin's lymphomas (NHLs). AIDS lymphomas are comprised of NHLs including Burkitt's lymphoma (BL) and primary cerebral lymphomas (PCLs). Almost 3% of all AIDS patients (2824 of 97,258 cases) developed NHL. Epstein-Barr virus (EBV) as a co-factor in AIDS lymphomagenesis has been studied: in 12 cases of 24 AIDS lymphomas EBV by DNA in situ hybridization was found. In an analysis of 6 primary cerebral lymphomas, .5 were positive for EBV DNA by Southern blotting. In Burkitt's lymphoma the characteristic genetic alteration affects the c-myc oncogene. In 1/3 of BL p53 mutations were found but none in the 43 NHLs suggesting that p53 mutations and c-myc activation act synergistically in the pathogenesis of these tumors. Cytotoxic agents dideoxyinosine, dideoxycytosine, and zidovudine may cause secondary neoplasia. 8 of 55 AIDS patients under zidovudine treatment developed high-grade lymphoma 23.8 months subsequently; recently doses were reduced. PCL was found in 21 of 90 patients. A 5.2 months survival was associated with combined treatment with cyclophosphamide, Oncovin (vincristine), methotrexate, etoposide, and cytosine arabinoside compared with 11.3 months with chemotherapy. Colony-stimulating factors (CSFs) alleviate drug-induced myelotoxicity and zidovudine-induced neutropenia, however, l8 of 11 patients receiving granulocyte-macrophage CSF developed hematological toxicity. Interleukine-2 produced by T-helper cells enhancing tumor cells cytotoxicity has been used in AIDS-associated cryptosporidial diarrhea and in 4 patients with AIDS lymphoma with modest response, but its stimulation of the HIV-infected substrate may increase viral proliferation.

  5. IKT 16: the first X-ray confirmed composite SNR in the SMC

    NASA Astrophysics Data System (ADS)

    Maitra, C.; Ballet, J.; Filipović, M. D.; Haberl, F.; Tiengo, A.; Grieve, K.; Roper, Q.

    2015-12-01

    Aims: IKT 16 is an X-ray and radio-faint supernova remnant (SNR) in the Small Magellanic Cloud (SMC). A detailed X-ray study of this SNR with XMM-Newton confirmed the presence of a hard X-ray source near its centre, indicating the detection of the first composite SNR in the SMC. With a dedicated Chandra observation we aim to resolve the point source and confirm its nature. We also acquire new ATCA observations of the source at 2.1 GHz with improved flux density estimates and resolution. Methods: We perform detailed spatial and spectral analysis of the source. With the highest resolution X-ray and radio image of the centre of the SNR available today, we resolve the source and confirm its pulsar wind nebula (PWN) nature. Further, we constrain the geometrical parameters of the PWN and perform spectral analysis for the point source and the PWN separately. We also test for the radial variations of the PWN spectrum and its possible east west asymmetry. Results: The X-ray source at the centre of IKT 16 can be resolved into a symmetrical elongated feature centring a point source, the putative pulsar. Spatial modelling indicates an extent of 5.2'' of the feature with its axis inclined at 82° east from north, aligned with a larger radio feature consisting of two lobes almost symmetrical about the X-ray source. The picture is consistent with a PWN which has not yet collided with the reverse shock. The point source is about three times brighter than the PWN and has a hard spectrum of spectral index 1.1 compared to a value 2.2 for the PWN. This points to the presence of a pulsar dominated by non-thermal emission. The expected Ė is ~1037 erg s-1 and spin period <100 ms. However, the presence of a compact nebula unresolved by Chandra at the distance of the SMC cannot completely be ruled out. The reduced images (FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/584/A

  6. VizieR Online Data Catalog: The first Fermi LAT SNR catalog (1SC) (Acero+, 2016)

    NASA Astrophysics Data System (ADS)

    Acero, F.; Ackermann, M.; Ajello, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caputo, R.; Caragiulo, M.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cohen, J. M.; Cohen-Tanugi, J.; Cominsky, L. R.; Condon, B.; Conrad, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Desiante, R.; Digel, S. W.; di Venere, L.; Drell, P. S.; Drlica-Wagner, A.; Favuzzi, C.; Ferrara, E. C.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gomez-Vargas, G. A.; Grenier, I. A.; Grondin, M.-H.; Guillemot, L.; Guiriec, S.; Gustafsson, M.; Hadasch, D.; Harding, A. K.; Hayashida, M.; Hays, E.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Hou, X.; Iafrate, G.; Jogler, T.; Johannesson, G.; Johnson!, A. S.; Ka, Mae T.; Katagiri, H.; Kataoka, J.; Katsuta, J.; Kerr, M.; Knodlseder, J.; Kocevski, D.; Kuss, M.; Laffon, H.; Lande, J.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Magill, J.; Maldera, S.; Marelli, M.; Mayer, M.; Mazziotta, M. N.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Moretti, E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nemmen, R.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Petrosian, V.; Piron, F.; Pivato, G.; Porter, T. A.; Raino, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Renaud, M.; Reposeur, T.; Rousseau, R.; Saz Parkinson, P. M.; Schmid, J.; Schulz, A.; Sgro, C.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Strong, A. W.; Suson, D. J.; Tajima, H.; Takahashi, H.; Tanaka, T.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tibolla, O.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Vianello, G.; Wells, B.; Wood, K. S.; Wood, M.; Yassine, M.; Den Hartog P. R.; Zimmer, S.

    2016-06-01

    We have systematically characterized the Fermi/LAT 1-100GeV emission from 36 months (from 2008 August 4 to 2011 August 4) in 279 regions containing known radio SNRs, identifying sources emitting in the regions and then determining the likelihood that the source nearest the SNR is associated with it. We found 102 candidates, 30 of which have sufficient spatial overlap and significance with the alternative IEMs to suggest they are the GeV counterparts to their corresponding radio SNRs and an additional 14 candidates which may also be related to the SNRs. (3 data files).

  7. SPR sensors in POF: a new experimental configuration for extended refractive index range and better SNR

    NASA Astrophysics Data System (ADS)

    Cennamo, N.; Coelho, L.; Guerreiro, A.; Jorge, P. A. S.; Zeni, L.

    2014-05-01

    In this work we present a new low cost SPR (Surface Plasmon Resonance) sensor configuration based on efficient higher-order mode filtering in plastic multimode fibers, using a tapered POF (Plastic Optical Fiber) after the sensor system, without decreasing the sensitivity of the sensor. In particular, we present the experimental results obtained with this new configuration. The experimental results have shown as the tapered POF after the sensor system influences the performances in terms of refractive index range and Signal-to-Noise Ratio (SNR).

  8. XMM-Newton observation of SNR J0533-7202 in the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Kavanagh, P. J.; Sasaki, M.; Whelan, E. T.; Maggi, P.; Haberl, F.; Bozzetto, L. M.; Filipović, M. D.; Crawford, E. J.

    2015-07-01

    Aims: We present an X-ray study of the supernova remnant SNR J0533-7202 in the Large Magellanic Cloud (LMC) and determine its physical characteristics based on its X-ray emission. Methods: We observed SNR J0533-7202 with XMM-Newton (background flare-filtered exposure times of 18 ks EPIC-pn and 31 ks EPIC-MOS1, EPIC-MOS2). We produced X-ray images of the supernova remnant, performed an X-ray spectral analysis, and compared the results to multi-wavelength studies. Results: The distribution of X-ray emission is highly non-uniform, with the south-west region much brighter than the north-east. The detected X-ray emission is correlated with the radio emission from the remnant. We determine that this morphology is most likely due to the supernova remnant expanding into a non-uniform ambient medium and not an absorption effect. We estimate the remnant size to be 53.9 (±3.4) × 43.6 (±3.4) pc, with the major axis rotated ~64° east of north. We find no spectral signatures of ejecta emission and infer that the X-ray plasma is dominated by swept up interstellar medium. Using the spectral fit results and the Sedov self-similar solution, we estimate the age of SNR J0533-7202 to be ~17-27 kyr, with an initial explosion energy of (0.09-0.83) × 1051 erg. We detected an X-ray source located near the centre of the remnant, namely XMMU J053348.2-720233. The source type could not be conclusively determined due to the lack of a multi-wavelength counterpart and low X-ray counts. We found that it is likely either a background active galactic nucleus or a low-mass X-ray binary in the LMC. Conclusions: We detected bright thermal X-ray emission from SNR J0533-7202 and determined that the remnant is in the Sedov phase of its evolution. The lack of ejecta emission prohibits us from typing the remnant with the X-ray data. Therefore, the likely Type Ia classification based on the local stellar population and star formation history reported in the literature cannot be improved upon. Based on

  9. Directional hearing aid using hybrid adaptive beamformer (HAB) and binaural ITE array

    NASA Astrophysics Data System (ADS)

    Shaw, Scott T.; Larow, Andy J.; Gibian, Gary L.; Sherlock, Laguinn P.; Schulein, Robert

    2002-05-01

    A directional hearing aid algorithm called the Hybrid Adaptive Beamformer (HAB), developed for NIH/NIA, can be applied to many different microphone array configurations. In this project the HAB algorithm was applied to a new array employing in-the-ear microphones at each ear (HAB-ITE), to see if previous HAB performance could be achieved with a more cosmetically acceptable package. With diotic output, the average benefit in threshold SNR was 10.9 dB for three HoH and 11.7 dB for five normal-hearing subjects. These results are slightly better than previous results of equivalent tests with a 3-in. array. With an innovative binaural fitting, a small benefit beyond that provided by diotic adaptive beamforming was observed: 12.5 dB for HoH and 13.3 dB for normal-hearing subjects, a 1.6 dB improvement over the diotic presentation. Subjectively, the binaural fitting preserved binaural hearing abilities, giving the user a sense of space, and providing left-right localization. Thus the goal of creating an adaptive beamformer that simultaneously provides excellent noise reduction and binaural hearing was achieved. Further work remains before the HAB-ITE can be incorporated into a real product, optimizing binaural adaptive beamforming, and integrating the concept with other technologies to produce a viable product prototype. [Work supported by NIH/NIDCD.

  10. Confronting AIDS.

    PubMed

    Squire, L

    1998-03-01

    By 2020, HIV/AIDS will be the leading infectious killer of young and middle-aged adults in the developing world. Past gains in life expectancy are already being eroded in some countries. Millions of lives can, however, be saved if developing country governments, the international community, and nongovernmental organizations act now. Although more than 11 million people have already died of AIDS, 2.3 billion people live in developing countries in which the disease has not yet spread beyond certain risk groups. If the spread of HIV is checked, the quality of care available to people who are infected with HIV will probably be better than it would be in the context of a full-blown AIDS epidemic. However, while governments need to respond urgently to HIV/AIDS, using resources to help people with AIDS will reduce the resources available for other investments, such as child education, providing safe drinking water, and building roads. Economics can help governments set priorities as they decide how best to allocate their available resources. Externalities, public goods, and redistribution are discussed. All countries will need to use some combination of preventive and coping measures. PMID:12293445

  11. "Aid Like a Paycheck: Engaging with Policymakers and Practitioners to Evaluate and Improve Financial Aid"

    ERIC Educational Resources Information Center

    Weissman, Evan; O'Connell, Jesse

    2016-01-01

    "Aid Like A Paycheck" is a large-scale pilot evaluation of whether an innovative approach to disbursing financial aid can improve academic and financial outcomes for low-income community college students. Lessons from the pilot evaluation were used to create and fine-tune a logic model depicting activities, outputs, mediators, and…

  12. Markov random field based automatic alignment for low SNR imagesfor cryo electron tomography

    SciTech Connect

    Amat, Fernando; Moussavi, Farshid; Comolli, Luis R.; Elidan, Gal; Horowitz, Mark

    2007-07-21

    We present a method for automatic full precision alignmentof the images in a tomographic tilt series. Full-precision automaticalignment of cryo electron microscopy images has remained a difficultchallenge to date, due to the limited electron dose and low imagecontrast. These facts lead to poor signal to noise ratio (SNR) in theimages, which causes automatic feature trackers to generate errors, evenwith high contrast gold particles as fiducial features. To enable fullyautomatic alignment for full-precision reconstructions, we frame theproblem probabilistically as finding the most likely particle tracksgiven a set of noisy images, using contextual information to make thesolution more robust to the noise in each image. To solve this maximumlikelihood problem, we use Markov Random Fields (MRF) to establish thecorrespondence of features in alignment and robust optimization forprojection model estimation. The resultingalgorithm, called RobustAlignment and Projection Estimation for Tomographic Reconstruction, orRAPTOR, has not needed any manual intervention for the difficult datasets we have tried, and has provided sub-pixel alignment that is as goodas the manual approach by an expert user. We are able to automaticallymap complete and partial marker trajectories and thus obtain highlyaccurate image alignment. Our method has been applied to challenging cryoelectron tomographic datasets with low SNR from intact bacterial cells,as well as several plastic section and x-ray datasets.

  13. Digital test signal generation: An accurate SNR calibration approach for the DSN

    NASA Technical Reports Server (NTRS)

    Gutierrez-Luaces, Benito O.

    1993-01-01

    In support of the on-going automation of the Deep Space Network (DSN) a new method of generating analog test signals with accurate signal-to-noise ratio (SNR) is described. High accuracy is obtained by simultaneous generation of digital noise and signal spectra at the desired bandwidth (base-band or bandpass). The digital synthesis provides a test signal embedded in noise with the statistical properties of a stationary random process. Accuracy is dependent on test integration time and limited only by the system quantization noise (0.02 dB). The monitor and control as well as signal-processing programs reside in a personal computer (PC). Commands are transmitted to properly configure the specially designed high-speed digital hardware. The prototype can generate either two data channels modulated or not on a subcarrier, or one QPSK channel, or a residual carrier with one biphase data channel. The analog spectrum generated is on the DC to 10 MHz frequency range. These spectra may be up-converted to any desired frequency without loss on the characteristics of the SNR provided. Test results are presented.

  14. Improving detection of low SNR targets using moment-based detection

    NASA Astrophysics Data System (ADS)

    Young, Shannon R.; Steward, Bryan J.; Hawks, Michael; Gross, Kevin C.

    2016-05-01

    Increases in the number of cameras deployed, frame rate, and detector array sizes have led to a dramatic increase in the volume of motion imagery data that is collected. Without a corresponding increase in analytical manpower, much of the data is not analyzed to full potential. This creates a need for fast, automated, and robust methods for detecting signals of interest. Current approaches fall into two categories: detect-before-track (DBT), which are fast but often poor at detecting dim targets, and track-before-detect (TBD) methods which can offer better performance but are typically much slower. This research seeks to contribute to the near real time detection of low SNR, unresolved moving targets through an extension of earlier work on higher order moments anomaly detection, a method that exploits both spatial and temporal information but is still computationally efficient and massively parallelizable. It was found that intelligent selection of parameters can improve probability of detection by as much as 25% compared to earlier work with higherorder moments. The present method can reduce detection thresholds by 40% compared to the Reed-Xiaoli anomaly detector for low SNR targets (for a given probability of detection and false alarm).

  15. Improving GNSS-R sea level determination through inverse modeling of SNR data

    NASA Astrophysics Data System (ADS)

    Strandberg, Joakim; Hobiger, Thomas; Haas, Rüdiger

    2016-08-01

    This paper presents a new method for retrieving sea surface heights from Global Navigation Satellite Systems reflectometry (GNSS-R) data by inverse modeling of SNR observations from a single geodetic receiver. The method relies on a B-spline representation of the temporal sea level variations in order to account for its continuity. The corresponding B-spline coefficients are determined through a nonlinear least squares fit to the SNR data, and a consistent choice of model parameters enables the combination of multiple GNSS in a single inversion process. This leads to a clear increase in precision of the sea level retrievals which can be attributed to a better spatial and temporal sampling of the reflecting surface. Tests with data from two different coastal GNSS sites and comparison with colocated tide gauges show a significant increase in precision when compared to previously used methods, reaching standard deviations of 1.4 cm at Onsala, Sweden, and 3.1 cm at Spring Bay, Tasmania.

  16. Multifrequency Radio Observations of SNR J0536-6735 (N 59B) with Associated Pulsar

    NASA Astrophysics Data System (ADS)

    Bozzetto, L. M.; Filipovic, M. D.; Crawford, E. J.; De Horta, A. Y.; Stupar, M.

    2012-06-01

    We present a study of new Australian Telescope Compact Array (ATCA) observations of supernova remnant, SNR J0536-6735. This remnant appears to follow a shell morphology with a diameter of D=36×29 pc (with 1 pc uncertainty in each direction). There is an embedded HII region on the northern limb of the remnant which made various analysis and measurements (such as flux density, spectral index and polarisation) difficult. The radio-continuum emission followed the same structure as the optical emission, allowing for extent and flux density estimates at 20 cm. We estimate the surface brightness at 1 GHz of 2.55×10^{-21} Wm^{-2} Hz^{-1} sr^{-1} for the SNR. Also, we detect a distinctive radio-continuum point source which confirms the previous suggestion of this remnant being associated with pulsar wind nebula (PWN). The tail of this remnant is not seen in the radio-continuum images and is only seen in the optical and X-ray images.

  17. HESS J1640-465 - an exceptionally luminous TeV gamma-ray SNR

    NASA Astrophysics Data System (ADS)

    Eger, Peter; Ohm, Stefan

    HESS J1640-465 is among the brightest Galactic TeV gamma-ray sources ever discovered by the High Energy Stereoscopic System (H.E.S.S.). Its likely association with the shell-type supernova remnant (SNR) G338.3-0.0 at a distance of ˜10 kpc makes it the most luminous Galactic source in the TeV regime. Our recent analysis of follow-up observations with H.E.S.S. reveal a significantly extended TeV morphology with a substantial overlap with the northern part of the SNR shell. Furthermore, the source features a seamless powerlaw spectrum over four orders of magnitude from GeV to TeV energies, with a spectral index of Gamma = 2.15± 0.10_mathrm{stat}± 0.10_mathrm{sys} and a cut-off energy of E_c = 7.3(+2.5}_{-1.8) TeV. These new spectral and morphological results suggest that a significant fraction of the TeV emission is likely of hadronic origin where the product of total proton energy and mean target density could be as high as W_p n_H ˜ 4 × 10(52}(d/10mathrm{kpc) )(2) erg cm(-3) . This would make HESS J1640-465 one of the most extreme and efficient Galactic particle accelerators.

  18. Is Cir X-1 associated with SNR G321.9- 0.3?

    NASA Astrophysics Data System (ADS)

    Mignani, Roberto

    2000-07-01

    Cir X-1 is one of the most intriguing galactic X-ray sources. It is a ~ 16.6 d variable X/radio source, a type I X-ray burster and a QPO emitter, which, in spite of an ambiguous optical counterpart classification, identify it as an LMXB. The source is embedded in a radio nebula, with finer structures protruding towards the centre of the nearby SNR G321.9-0.3. This prompted the speculation about a connection between the two, with Cir X-1 being a runaway binary originated from the supernova explosion. In this case, a a significant proper motion would be expected for Cir X-1. Since this source has been already imaged by HST in 1992, one more WFPC2 image could allow to measure its proper motion in the expected direction. This, together with securing the association with the SNR, will constrain the age of the neutron star in Cir X-1, crucial to trace its magnetic field evolution in an accretion regime and to provide observational inputs to theoretical models. , bf This is a case where a single, very simple, and short observation can greatly contribute to solve an important astrophysical issue.

  19. Improving SNR of fiber Bragg grating sensor by digital signal processing

    NASA Astrophysics Data System (ADS)

    Ning, Jing; Yang, Shangming; Zhang, Yan; Cui, Hong-liang

    2007-09-01

    Traditionally, the broadband amplified spontaneous emission (ASE) source is considered to be used as the light source for the fiber Bragg grating (FBG) sensing technology. However, this kind of light source has some disadvantages - the huge volume and the high power consumption. These shortages will hamper the development of FBG sensing technology in some kind of applications such as unattended sensor and space environment. In this paper, the authors will present a new approach, the usage of the light emitted diode (LED) as the light source. The LED source is very compact, easy to integrate, and significantly reduced the cost and power consumption. But the light density of LED is so weak that the useful signal is almost buried by noise. A solution proposed by our group is to enhance SNR by digital signal processing (DSP) technology, including high frequency modulation, phase-lock amplifier, encoding on LED and decoding on the synchronistic detection. The experimental results show our effort could significantly increases the signal noise ratio (SNR) and make FBG sensor practical on application.

  20. The Northern Rims of SNR RCW 86 - Chandra's Recent Observations and their Implications for Particle Acceleration

    NASA Astrophysics Data System (ADS)

    Castro, D.

    2016-06-01

    The Chandra observations towards the northwest (NW) and northeast (NE) rims of supernova remnant (SNR) RCW 86 reveal great detail about the characteristics of the shocks, particle acceleration and the local environments in these 2 distinct regions. Both the NW and NE of RCW 86 show clear evidence of non-thermal X-ray emission, identified as synchrotron radiation from shock-accelerated electrons with TeV energies, interacting with the compressed, and probably amplified, local magnetic field. Magnetic field amplification (MFA) is broadly believed to result from, and contribute to, cosmic ray acceleration at the shocks of SNRs. However, we still lack a detailed understanding of the particle acceleration mechanism, and with this study we address the connection between the shock properties and ambient medium with MFA. The Chandra observations of RCW 86 allowed us to constrain the magnitude of the post-shock magnetic field in the NE and NW rims by deriving synchrotron filament widths, and also the densities in these regions, using thermal emission co-located with the non-thermal rims. I will discuss our analysis in detail and comment on how MFA appears to be related to certain characteristics of the SNR shock.

  1. SNR Loss: A new objective measure for predicting speech intelligibility of noise-suppressed speech

    PubMed Central

    Ma, Jianfen; Loizou, Philipos C.

    2010-01-01

    Most of the existing intelligibility measures do not account for the distortions present in processed speech, such as those introduced by speech-enhancement algorithms. In the present study, we propose three new objective measures that can be used for prediction of intelligibility of processed (e.g., via an enhancement algorithm) speech in noisy conditions. All three measures use a critical-band spectral representation of the clean and noise-suppressed signals and are based on the measurement of the SNR loss incurred in each critical band after the corrupted signal goes through a speech enhancement algorithm. The proposed measures are flexible in that they can provide different weights to the two types of spectral distortions introduced by enhancement algorithms, namely spectral attenuation and spectral amplification distortions. The proposed measures were evaluated with intelligibility scores obtained by normal-hearing listeners in 72 noisy conditions involving noise-suppressed speech (consonants and sentences) corrupted by four different maskers (car, babble, train and street interferences). Highest correlation (r=−0.85) with sentence recognition scores was obtained using a variant of the SNR loss measure that only included vowel/consonant transitions and weak consonant information. High correlation was maintained for all noise types, with a maximum correlation (r=−0.88) achieved in street noise conditions. PMID:21503274

  2. Fiscal output data produce versatile graphic-numeric charts

    NASA Technical Reports Server (NTRS)

    Powell, R. W.; Romo, J. J.

    1971-01-01

    Refined computerized plotting system produces low-cost graphic-numeric charts that illustrate fiscal data on monthly incremental or cumulative basis, or both. Output is in the form of hard copy or microfilm, or visual-aid transparencies prepared from hard copy for rapid management status presentations.

  3. Classroom Aids

    ERIC Educational Resources Information Center

    Science Activities: Classroom Projects and Curriculum Ideas, 2007

    2007-01-01

    This article describes 6 aids for science instruction, including (1) the use of fudge to represent lava; (2) the "Living by Chemistry" program, designed to make high school chemistry more accessible to a diverse pool of students without sacrificing content; (3) NOAA and NSTA's online coral reef teaching tool, a new web-based "science toolbox" for…

  4. Dietitian Aide.

    ERIC Educational Resources Information Center

    Texas Tech. Univ., Lubbock. School of Home Economics.

    This course of study for the dietitian aide is one of a series available for use by teacher-coordinators and students in Grade 11 and 12 home economics cooperative education programs. Based on job analysis interviews with health care facilities personnel, this course was prepared by teachers and Instructional Materials Center staff, field-tested,…

  5. Floriculture Aide.

    ERIC Educational Resources Information Center

    Martin, Joyce; Looney, Era

    Designed for use in a self-paced, open-entry/open-exit vocational training program for a floriculture aide, this program guide is one of six for teachers of adult women offenders from a correctional institution. Module topic outlines and sample lesson plans are presented on eleven topics: occupational opportunities in the retail florist industry;…

  6. [Analysis and experimental verification of SNR for a far ultraviolet imaging spectrograph in 115-180 nm].

    PubMed

    Yu, Lei; Lin, Guan-yu; Qu, Yi; Wang, Shu-rong

    2010-11-01

    An 115-180 nm far ultraviolet limb imaging spectrograph prototype was developed for the detection of the ionosphere. For the particularity of the wavelength band in far ultraviolet, the signals accepted by the instrument are very weak. So the sensitivity and signal-noise-ratio (SNR) are two important performance parameters for the spectrograph. In the present paper, based on the signal statistical detection theory and the threshold detection theory, a method for calculation of the sensitivity and SNR has been proposed. Firstly, the probabilities of the accepted signals and system noises were analyzed. Secondly, the mathematical expressions of sensitivity and SNR of the instrument were deduced by introducing the detection probability factor and the false alarm rate factor. Based on the calculation of the sensitivity and the intensity of the particles radiation wavelengths, it was found that the sensitivity can meet the need of the detection. Finally, the SNR of the instrument were analyzed by using the method, and the coherent experiment was built to prove the results. The error of theoretic calculation and experimental results can be accepted. It indicates that the SNR analysis method is feasible. PMID:21284204

  7. A complete radio study of SNR G15.4+0.1 from new GMRT observations

    NASA Astrophysics Data System (ADS)

    Supan, L.; Castelletti, G.; Joshi, B. C.; Surnis, M. P.; Supanitsky, D.

    2015-04-01

    Aims: The supernova remnant (SNR) G15.4+0.1 is considered to be the possible counterpart of the γ-ray source HESS J1818-154. With the goal of getting a complete view of this remnant and understanding the nature of the γ-ray flux, we conducted a detailed radio study that includes the search for pulsations and a model of the broadband emission for the SNR G15.4+0.1/HESS J1818-154 system. Methods: Low-frequency imaging at 624 MHz and pulsar observations at 624 and 1404 MHz towards G15.4+0.1 were carried out with the Giant Metrewave Radio Telescope (GMRT). We correlated the new radio data with observations of the source at X-ray and infrared wavelengths from XMM-Newton and Herschel observatories, respectively. To characterize the neutral hydrogen (HI) medium towards G15.4+0.1, we used data from the Southern Galactic Plane Survey. We modelled the spectral energy distribution (SED) using both hadronic and leptonic scenarios. Results: From the combination of the new GMRT observations with existing data, we derived a continuum spectral index α = -0.62 ± 0.03 for the whole remnant. The local synchrotron spectra of G15.4+0.1, calculated from the combination of the GMRT data with 330 MHz observations from the Very Large Array, tends to be flatter in the central part of the remnant, accompanying the region where the blast wave is impinging molecular gas. No spectral index trace was found indicating the radio counterpart to the pulsar wind nebula proposed from X-ray observations. In addition, the search for radio pulsations yielded negative results. Emission at far-infrared wavelengths is observed in the region where the SNR shock is interacting with dense molecular clumps. We also identified HI features forming a shell that wraps most of the outer border of G15.4+0.1. Characteristic parameters were estimated for the shocked HI gas. We found that either a purely hadronic or leptonic model is compatible with the broadband emission known so far.

  8. Digital test signal generation: An accurate SNR calibration approach for the DSN

    NASA Technical Reports Server (NTRS)

    Gutierrez-Luaces, B. O.

    1991-01-01

    A new method of generating analog test signals with accurate signal to noise ratios (SNRs) is described. High accuracy will be obtained by simultaneous generation of digital noise and signal spectra at a given baseband or bandpass limited bandwidth. The digital synthesis will provide a test signal embedded in noise with the statistical properties of a stationary random process. Accuracy will only be dependent on test integration time with a limit imposed by the system quantization noise (expected to be 0.02 dB). Setability will be approximately 0.1 dB. The first digital SNR generator to provide baseband test signals is being built and will be available in early 1991.

  9. A Detailed Observation of a LMC SNR, DEM L241, with XMM-Newton

    NASA Astrophysics Data System (ADS)

    Bamba, Aya; Ueno, Masaru; Nakajima, Hiroshi; Mori, Koji; Koyama, Katsuji

    We report on an XMM-Newton observation of the supernova remnant (SNR) DEM L241 in the Large Magellanic Cloud. In the soft band image, the emission shows an elongated structure, like a killifish (Head and Tail), with a central point source, named as XMMU J053559.3-673509 (Eye). The Eye's spectrum is well reproduced with a power-law model. The source has neither significant coherent pulsations nor time variabilities. Its luminosity and spectrum remind us that the source might be a pulsar and/or pulsar wind nebula in DEM L241. The spectra of Head and Tail are well reproduced by a non-equilibrium ionization plasma model with over-abundant Ne and under-abundant Fe, suggesting that the progenitor of DEM L241 is a very massive star.

  10. Deep Morphological and Spectral Study of the SNR RCW 86 with Fermi-LAT

    NASA Astrophysics Data System (ADS)

    Ajello, M.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Caliandro, G. A.; Cameron, R. A.; Caragiulo, M.; Cavazzuti, E.; Charles, E.; Chekhtman, A.; Ciprini, S.; Cohen-Tanugi, J.; Condon, B.; Costanza, F.; Cutini, S.; D'Ammando, F.; de Palma, F.; Desiante, R.; Di Lalla, N.; Di Mauro, M.; Di Venere, L.; Drell, P. S.; Dubner, G.; Dumora, D.; Duvidovich, L.; Favuzzi, C.; Focke, W. B.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giacani, E.; Giglietto, N.; Glanzman, T.; Green, D. A.; Grenier, I. A.; Guiriec, S.; Hays, E.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Jogler, T.; Jóhannesson, G.; Jung-Richardt, I.; Kensei, S.; Kuss, M.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Magill, J.; Maldera, S.; Manfreda, A.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Negro, M.; Nuss, E.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Reposeur, T.; Schmid, J.; Schulz, A.; Sgrò, C.; Simone, D.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Thayer, J. B.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Vianello, G.; Vink, J.; Wood, K. S.; Yassine, M.

    2016-03-01

    RCW 86 is a young supernova remnant (SNR) showing a shell-type structure at several wavelengths and is thought to be an efficient cosmic-ray (CR) accelerator. Earlier Fermi Large Area Telescope results reported the detection of γ-ray emission coincident with the position of RCW 86 but its origin (leptonic or hadronic) remained unclear due to the poor statistics. Thanks to 6.5 years of data acquired by the Fermi-LAT and the new event reconstruction Pass 8, we report the significant detection of spatially extended emission coming from RCW 86. The spectrum is described by a power-law function with a very hard photon index ({{Γ }}=1.42+/- {0.1}{{stat}}+/- {0.06}{{syst}}) in the 0.1-500 GeV range and an energy flux above 100 MeV of (2.91+/- {0.8}{{stat}}+/- {0.12}{{syst}}) × {10}-11 erg cm-2 s-1. Gathering all the available multiwavelength (MWL) data, we perform a broadband modeling of the nonthermal emission of RCW 86 to constrain parameters of the nearby medium and bring new hints about the origin of the γ-ray emission. For the whole SNR, the modeling favors a leptonic scenario in the framework of a two-zone model with an average magnetic field of 10.2 ± 0.7 μG and a limit on the maximum energy injected into protons of 2 × 1049 erg for a density of 1 cm-3. In addition, parameter values are derived for the north-east and south-west (SW) regions of RCW 86, providing the first indication of a higher magnetic field in the SW region.

  11. Observations of the Monoceros SNR/Rosette nebula interacting region with the HEGRA system of IACTs

    NASA Astrophysics Data System (ADS)

    Lucarelli, F.; Konopelko, A.; Fonseca, V.; HEGRA Collaboration

    2001-08-01

    The array of 5 imaging atmospheric ˇCerenkov telescopes (IACTs) deployed at La Palma of Canary Island, and operated by the HEGRA (High Energy Gamma Ray Astronomy) collaboration, was used for the observations of the interaction region of the Monoceros SNR with the dense Rosette nebula for a total of about 120 hrs and 20 hrs in ONsource and OFF-source mode, respectively. At present the performance of the IACTs array reveals the energy threshold of 500 GeV and the angular resolution of 0.1° for γrays. Using the HEGRA system of IACTs of rather large field of view (4.3 degree in diameter), we have mapped the extended sky region of 2° × 2° associated with the Monoceros SNR/Rosette nebula and which is centered towards the hard spectrum X-ray point source SAX J0635+533. The EGRET unidentified source of diffuse γ-ray emission (3EG J0634+0521) observed in the energy range between 100 MeV 10 GeV, was effectively in the field of view of our present observations. Based on the Monte Carlo simulations and real data we have studied the response of the IACTs array over its 5 · 10-3 str field of view with respect to the cosmic rays and diffuse γ-ray emission. We have derived a normalization function which takes into account the slightly non uniform sensitivity to the γ-ray fluxes (with the variation of 10%) within the angular distance of 1 deg from the joint optical axis of the telescopes' array after the analysis by mean scaled Width. Here we present the result of the data analysis and its physical interpretation. Correspondence to: F. Lucarelli (Fabrizio.Lucarelli@mpi-hd.mpg.de)

  12. Serial Input Output

    SciTech Connect

    Waite, Anthony; /SLAC

    2011-09-07

    Serial Input/Output (SIO) is designed to be a long term storage format of a sophistication somewhere between simple ASCII files and the techniques provided by inter alia Objectivity and Root. The former tend to be low density, information lossy (floating point numbers lose precision) and inflexible. The latter require abstract descriptions of the data with all that that implies in terms of extra complexity. The basic building blocks of SIO are streams, records and blocks. Streams provide the connections between the program and files. The user can define an arbitrary list of streams as required. A given stream must be opened for either reading or writing. SIO does not support read/write streams. If a stream is closed during the execution of a program, it can be reopened in either read or write mode to the same or a different file. Records represent a coherent grouping of data. Records consist of a collection of blocks (see next paragraph). The user can define a variety of records (headers, events, error logs, etc.) and request that any of them be written to any stream. When SIO reads a file, it first decodes the record name and if that record has been defined and unpacking has been requested for it, SIO proceeds to unpack the blocks. Blocks are user provided objects which do the real work of reading/writing the data. The user is responsible for writing the code for these blocks and for identifying these blocks to SIO at run time. To write a collection of blocks, the user must first connect them to a record. The record can then be written to a stream as described above. Note that the same block can be connected to many different records. When SIO reads a record, it scans through the blocks written and calls the corresponding block object (if it has been defined) to decode it. Undefined blocks are skipped. Each of these categories (streams, records and blocks) have some characteristics in common. Every stream, record and block has a name with the condition that each

  13. Body size and work output.

    PubMed

    Satyanarayana, K; Naidu, A N; Chatterjee, B; Rao, N

    1977-03-01

    The relationship between work output and anthropometric, biochemical, and socioeconomic varables was studied in 57 male industrial workers engaged in the production of detonator fuses. These workers were studied for 3 months and their daily work output was carefully measured. Work output was measured in terms of the number of fuses produced per day. Clinical and biochemical examination indicated that their current nutritional status was adequate. Among the parameters studied only body weight, height, and lean body weight were significantly correlated with work output. Body weight and lean body weight were significantly correlated (P less than 0.001) with work output even after removing the influence of height by partial correlation. Total daily work output was significantly higher (P less than 0.01) in those with higher body weight and lean body weight. The rate of work was also higher in the higher body weight group

  14. Lightweight multiple output converter development

    NASA Technical Reports Server (NTRS)

    Kisch, J. J.; Martinelli, R. M.

    1978-01-01

    A high frequency, multiple output power conditioner was developed and breadboarded using an eight-stage capacitor diode voltage multiplier to provide +1200 Vdc, and a three-stage for -350 Vdc. In addition, two rectifier bridges were capacitively coupled to the eight-stage multiplier to obtain 0.5 and 0.65 a dc constant current outputs referenced to +1200 Vdc. Total power was 120 watts, with an overall efficiency of 85 percent at the 80 kHz operating frequency. All outputs were regulated to three percent or better, with complete short circuit protection. The power conditioner component weight and efficiency were compared to the equivalent four outputs of the 10 kHz conditioner for the 8 cm ion engine. Weight reduction for the four outputs was 557 grams; extrapolated in the same ratio to all nine outputs, it would be 1100 to 1400 grams.

  15. HIV/AIDS Basics

    MedlinePlus

    ... Enter ZIP code or city Follow Act Against AIDS Act Against AIDS @talkHIV Act Against AIDS Get Email Updates on AAA Anonymous Feedback HIV/AIDS Media Infographics Syndicated Content Podcasts Slide Sets HIV/ ...

  16. Nonlinear input-output systems

    NASA Technical Reports Server (NTRS)

    Hunt, L. R.; Luksic, Mladen; Su, Renjeng

    1987-01-01

    Necessary and sufficient conditions that the nonlinear system dot-x = f(x) + ug(x) and y = h(x) be locally feedback equivalent to the controllable linear system dot-xi = A xi + bv and y = C xi having linear output are found. Only the single input and single output case is considered, however, the results generalize to multi-input and multi-output systems.

  17. Is There a Role for Speech Output in Interventions for Persons with Autism? A Review.

    ERIC Educational Resources Information Center

    Schlosser, Ralf W.; Blischak, Doreen M.

    2001-01-01

    This review of the literature synthesizes theory and research on the use of speech output communication aids to determine potential benefits for persons with autism. Although results suggest such aids are likely to be useful with this population, the paper urges research into the characteristics of synthetic speech in conjunction with the learning…

  18. Enhanced performance CCD output amplifier

    DOEpatents

    Dunham, Mark E.; Morley, David W.

    1996-01-01

    A low-noise FET amplifier is connected to amplify output charge from a che coupled device (CCD). The FET has its gate connected to the CCD in common source configuration for receiving the output charge signal from the CCD and output an intermediate signal at a drain of the FET. An intermediate amplifier is connected to the drain of the FET for receiving the intermediate signal and outputting a low-noise signal functionally related to the output charge signal from the CCD. The amplifier is preferably connected as a virtual ground to the FET drain. The inherent shunt capacitance of the FET is selected to be at least equal to the sum of the remaining capacitances.

  19. Comparison of Onset and Steady-State Responses of Hearing Aids: Implications for Use of the Auditory Brainstem Response in the Selection of Hearing Aids.

    ERIC Educational Resources Information Center

    Gorga, Michael P.; And Others

    1987-01-01

    Input-output (I/O) functions of hearing aids were measured in response to a 2000 Hz tone burst, having 0.5 ms rise/fall time and 10 ms duration. Findings indicated that the steady-state output limitation characteristics of hearing aids cannot be estimated from their onset responses. (Author/DB)

  20. NOTE: The utility of pelvic coil SNR testing in the quality assurance of a clinical MRgFUS system

    NASA Astrophysics Data System (ADS)

    Gorny, Krzysztof R.; Hangiandreou, Nicholas J.; Ward, Heidi A.; Hesley, Gina K.; Brown, Douglas L.; Felmlee, Joel P.

    2009-04-01

    During MRI-guided focused ultrasound (MRgFUS) treatments of uterine fibroids using ExAblate®2000, tissue ablations are delivered by a FUS transducer while MR imaging is performed with a pelvic receiver coil. The consistency of the pelvic coil performance is crucial for reliable MR temperature measurements as well as detailed anatomic imaging in patients. Test sonications in a gel phantom combined with MR thermometry are used to test the performance of the FUS transducer prior to each treatment. As we show, however, these tests do not adequately evaluate receiver coil performance prior to clinical use. This could become a problem since the posterior part of the coil is frequently moved and can malfunction. The aim of this work is to demonstrate the utility of the signal-to-noise ratio (SNR) as a reliable indicator of pelvic coil performance. Slight modification of the vendor-provided coil support was accomplished to assure reproducible coil positioning. The SNR was measured in a gel phantom using axial acquisitions from the 3D-localizer scan. MR temperature and SNR measurements were obtained using a degraded receiver coil (with posterior element removed) and a known faulty coil, and compared to those obtained with a fully functioning coil. While the MR temperature-based tests were insensitive to change in pelvic coil performance, (degraded, p = 0.24; faulty, p = 0.28), the SNR tests were highly sensitive to coil performance, (degraded, p < 0.001; faulty, p < 0.001). Additional clinical data illustrate the utility of SNR testing of the receiver coil. These tests require minimal (or possibly no) additional scan time and have proven to be effective in our clinical practice.

  1. Manufacturing Aids

    NASA Technical Reports Server (NTRS)

    1989-01-01

    During a research program, MMTC/Textron invented a computer-aided automatic robotic system for spraying hot plasma onto a turbine blade. The need to control the thickness of the plasma deposit led to the development of advanced optical gaging techniques to monitor and control plasma spray build-up on blade surfaces. The techniques led to computerized optical gages for inspecting aircraft, industrial turbine blades, etc. MMTC offers 10 standard commercial robotic gages. The system also generates two dimensional profiles for assessing status and specifying repairs to the electromechanical cathodes used to make the parts. It is capable of accuracies to a ten-thousandth of an inch. An expanded product line is currently marketed. The gages offer multiple improvements in quality control and significant savings.

  2. Telemetry SNR improvement using the DSN Advanced Receiver with results for Pioneer 10

    NASA Technical Reports Server (NTRS)

    Hurd, W. J.; Brown, D. H.; Vilnrotter, V. A.; Wiggins, J. D.

    1988-01-01

    A series of tracking tests was conducted in the spring of 1987 to demonstrate the reduced tracking threshold and the improved telemetry singal-to-noise-ratio performance of the DSN Advanced Receiver compared to current operational DSN systems. The Pioneer 10 spacecraft, which is now out of the solar system, was tracked on foud days. The Advanced Receiver achieved an improvement in telemetry SNR of 1 to 1.5 dB over the operational system. It was demonstrated that the spacecraft carrier signal is stable enough for tracking with a receiver carrier loop bandwidth of 0.5 Hz in the one-way mode and 0.1 Hz in the three-way mode, and that the Advanced Receiver is stable at 0.1 Hz. This reduces tracking threshold by 10 to 15 dB compared to current receivers, which have minimum loop bandwidths of 1 to 3 Hz. Thus, the Advanced Receiver will enable tracking of the Pioneer 10 spacecraft until its power source fails, circa 2000, which would not be possible with the current DSN system.

  3. Optimizing binary phase and amplitude filters for PCE, SNR, and discrimination

    NASA Technical Reports Server (NTRS)

    Downie, John D.

    1992-01-01

    Binary phase-only filters (BPOFs) have generated much study because of their implementation on currently available spatial light modulator devices. On polarization-rotating devices such as the magneto-optic spatial light modulator (SLM), it is also possible to encode binary amplitude information into two SLM transmission states, in addition to the binary phase information. This is done by varying the rotation angle of the polarization analyzer following the SLM in the optical train. Through this parameter, a continuum of filters may be designed that span the space of binary phase and amplitude filters (BPAFs) between BPOFs and binary amplitude filters. In this study, we investigate the design of optimal BPAFs for the key correlation characteristics of peak sharpness (through the peak-to-correlation energy (PCE) metric), signal-to-noise ratio (SNR), and discrimination between in-class and out-of-class images. We present simulation results illustrating improvements obtained over conventional BPOFs, and trade-offs between the different performance criteria in terms of the filter design parameter.

  4. Modeling post-explosion anisotropies of ejecta in SNR Cassiopeia A

    NASA Astrophysics Data System (ADS)

    Orlando, S.; Miceli, M.; Pumo, M.; Bocchino, F.

    2016-06-01

    Supernova remnats (SNRs) show a complex morphology characterized by an inhomogeneous spatial distribution of ejecta, believed to reflect pristine structures and features of the progenitor supernova (SN) explosion. Filling the gap between SN explosions and their remnants is very important for a comprehension of the origin of present-day structure of ejecta in SNRs and to probe and constraint current models of SN explosions. The SNR Cassiopeia A (Cas A) is an attractive laboratory for studying the SNe-SNRs connection, being one of the best studied SNRs for which its 3D structure is known. We present a three-dimensional hydrodynamic model describing the evolution of Cas A from the immediate aftermath of the SN explosion to its expansion through the interstellar medium, taking into account the distribution of element abundances of the ejecta, the back reaction of accelerated cosmic rays at the shock front, and the deviations from equilibrium of ionizazion for the most important elements. We use the model to derive the physical parameters characterizing the SN explosion and reproducing the today morphology of Cas A.

  5. X-ray emission from charge exchange in the Cygnus Loop SNR

    NASA Astrophysics Data System (ADS)

    Roberts, Shawn R.; Wang, Q. Daniel

    2015-05-01

    The Cygnus Loop has been the focus of substantial debate concerning the contribution of charge exchange (CX) to supernova remnant (SNR) X-ray emission. We take advantage of a distinct feature of CX, enhanced Kα forbidden line emission, and employ the energy centroid of the O VII Kα triplet as a diagnostic. Based on X-ray spectra extracted from an extensive set of Suzaku observations, we measure the energy centroid shifts of the triplet on and off the shock rim of the remnant. We find that enhanced forbidden to resonance line emission exists throughout much of the rim and this enhancement azimuthally correlates with non-radiative Hα filaments, a tracer of strong neutral-plasma interaction in the optical. We also show that alternative mechanisms cannot explain the observed enhancement. These results demonstrate the need to model the CX contribution to the X-ray emission of SNRs, particularly for shocks propagating in a partially neutral medium. Such modelling may be critically important to the correct measurements of the ionization, thermal, and chemical properties of SNRs.

  6. Electronic filters, hearing aids and methods

    NASA Technical Reports Server (NTRS)

    Engebretson, A. Maynard (Inventor)

    1995-01-01

    An electronic filter for an electroacoustic system. The system has a microphone for generating an electrical output from external sounds and an electrically driven transducer for emitting sound. Some of the sound emitted by the transducer returns to the microphone means to add a feedback contribution to its electrical output. The electronic filter includes a first circuit for electronic processing of the electrical output of the microphone to produce a first signal. An adaptive filter, interconnected with the first circuit, performs electronic processing of the first signal to produce an adaptive output to the first circuit to substantially offset the feedback contribution in the electrical output of the microphone, and the adaptive filter includes means for adapting only in response to polarities of signals supplied to and from the first circuit. Other electronic filters for hearing aids, public address systems and other electroacoustic systems, as well as such systems and methods of operating them are also disclosed.

  7. Electronic filters, hearing aids and methods

    NASA Technical Reports Server (NTRS)

    Engebretson, A. Maynard (Inventor); O'Connell, Michael P. (Inventor); Zheng, Baohua (Inventor)

    1991-01-01

    An electronic filter for an electroacoustic system. The system has a microphone for generating an electrical output from external sounds and an electrically driven transducer for emitting sound. Some of the sound emitted by the transducer returns to the microphone means to add a feedback contribution to its electical output. The electronic filter includes a first circuit for electronic processing of the electrical output of the microphone to produce a filtered signal. An adaptive filter, interconnected with the first circuit, performs electronic processing of the filtered signal to produce an adaptive output to the first circuit to substantially offset the feedback contribution in the electrical output of the microphone, and the adaptive filter includes means for adapting only in response to polarities of signals supplied to and from the first circuit. Other electronic filters for hearing aids, public address systems and other electroacoustic systems, as well as such systems, and methods of operating them are also disclosed.

  8. Measuring Air-Ionizer Output

    NASA Technical Reports Server (NTRS)

    Lonborg, J. O.

    1985-01-01

    Test apparatus checks ion content of airstream from commercial air ionizer. Apparatus ensures ion output is sufficient to neutralize static charges in electronic assembly areas and concentrations of positive and negative ions are balanced.

  9. Output optics for laser velocimeters

    NASA Technical Reports Server (NTRS)

    Lynch, Dana H. (Inventor); Gunter, William D. (Inventor); Mcalister, Kenneth W. (Inventor)

    1993-01-01

    Space savings are effected in the optical output system of a laser velocimeter. The output system is comprised of pairs of optical fibers having output ends from which a beam of laser light emerges, a transfer lens for each light beam, and at least one final (LV) lens for receiving the light passing through the transfer lenses and for focussing that light at a common crossing point or area. In order to closely couple the transfer lenses to the final lens, each transfer lens is positioned relative to the final lens receiving light therefrom such that the output waist of the corresponding beam received by the final lens from the transfer lens is a virtual waist located before the transfer lens.

  10. Research on output feedback control

    NASA Technical Reports Server (NTRS)

    Calise, Anthony J.

    1988-01-01

    A summary is presented of the main results obtained during the course of research on output feedback control. The term output feedback is used to denote a controller design approach which does not rely on an observer to estimate the states of the system. Thus, the order of the controller is fixed, and can even be zero order, which amounts to constant gain ouput feedback. The emphasis has been on optimal output feedback. That is, a fixed order controller is designed based on minimizing a suitably chosen quadratic performance index. A number of problem areas that arise in this context have been addressed. These include developing suitable methods for selecting an index of performance, both time domain and frequency domain methods for achieving robustness of the closed loop system, developing canonical forms to achieve a minimal parameterization for the controller, two time scale design formulations for ill-conditioned systems, and the development of convergent numerical algorithms for solving the output feedback problem.

  11. Crawling Aid

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The Institute for the Achievement of Human Potential developed a device known as the Vehicle for Initial Crawling (VIC); the acronym is a tribute to the crawler's inventor, Hubert "Vic" Vykukal; is an effective crawling aid. The VIC is used by brain injured children who are unable to crawl due to the problems of weight-bearing and friction, caused by gravity. It is a rounded plywood frame large enough to support the child's torso, leaving arms and legs free to move. On its underside are three aluminum discs through which air is pumped to create an air-bearing surface that has less friction than a film of oil. Upper side contains the connection to the air supply and a pair of straps which restrain the child and cause the device to move with him. VIC is used with the intent to recreate the normal neurological connection between brain and muscles. Over repetitive use of the device the child develops his arm and leg muscles as well as coordination. Children are given alternating therapy, with and without the VIC until eventually the device is no longer needed.

  12. X-ray, optical, and radio properties of the extensive SNR population in M83

    NASA Astrophysics Data System (ADS)

    Blair, W.; Long, S. K.; Winkler, F.; Soria, R.; Kuntz, D. K.; Plucinsky, P. P.; Dopita, A. M.

    2016-06-01

    The nearly face-on spiral galaxy M83 (d=4.6 Mpc) provides a significant opportunity for finding and studying a large and diverse sample of SNRs all at the same distance, given its active star formation, a starburst nuclear region, and at least six SNe since 1923. As the result of a concerted effort involving ground and spaced-based studies at radio (ATCA), optical and NIR (Magellan 6.5m and HST), and X-ray (Chandra) wavelengths, we have identified almost 300 SNRs in M83. Of these, at least 87 and 47 were detected in the X-ray and radio bands. Some 227 of the SNR candidates are within the regions observed in [Fe II] 1.64 microns with HST WFC3/IR, and we detect ∼100 of them, including ~8 in dusty regions where the [Fe II] emission was the primary means of identification. Follow-up ground-based spectroscopy of 99 of the 300 SNRs with Gemini-S and the GMOS instrument shows that essentially all of the SNRs identified in ground-based imaging have the [S II]/Halpha ratios expected of bona fide SNRs, and that most of the SNRs in the sample are “normal ISM-dominated” SNRs, in the sense that the line widths are narrow and the spectra look like radiative shocks. We have studied a number of interesting individual SNRs and historical SNe counterparts, as well as investigating the ensemble population of nearly 300 SNRs to better understand their properties as a group, their evolution, and their impact on their host galaxy. Of particular interest is a set of the smallest diameter (and hence presumably youngest) objects measured with HST, where the 0.04arcsec WFC3-UVIS pixels correspond to ~1 pc. One SNR has very broad emission lines and given its small size, was most likely a SN that occurred during the last century but was missed. A number of the other objects are comparable to the Crab Nebula or Cas A in size, but very few show the high velocities and spectral signatures of ejecta. Rather, their spectra show low velocities and “normal” ISM-dominated emissions, albeit

  13. An XMM Archival Study of the LMC SNR N132D

    NASA Astrophysics Data System (ADS)

    Plucinsky, Paul

    We propose to study the X-ray brightest supernova remnant (SNR) in the Large Magellanic Cloud (LMC) N132D to determine the abundances of the high Z products of nucleosynthesis (Si, S, Ca, Ar,etc.) relative to Fe and compare those values to current models of nucleosynthetic yields. We will also characterize the evolutionary parameters of the SNR (age, initial explosion energy, average initial ambient density) to place this remnant in context with studies of other remnants at different evolutionary stages. We intend to take advantage of the unique opportunity presented by the existing ~900 ks of observations acquired by XMM-Newton over the past 10 years. N132D has been routinely observed as a calibration target but the full scientific potential of these data have yet to be realized. These archival data represent the equivalent of a ``Large Program'' which would be difficult or impossible to acquire under a Guest Observer program. N132D has been extensively studied at other wavelengths and has been classified as an 'O-rich' remnant based on the optical spectra. The abundances derived from the optical suggest the progenitor was a massive star, perhaps as massive as 35 or more solar masses. The detection of only C, O, Ne, Mg, and Si in the ejecta suggest the progenitor may have been a WO Wolf Rayet star with an O rich mantle which did not mix with the deeper layers. The spectra of the bright optical knots do not show any emission from elements with higher Z than Si, yet the nucleosynthesis models predict significant quantities of these higher Z elements. Our preliminary analysis of the deep XMM-Newton data clearly show emission lines from S, Ar, Ca, and Fe, with indications of other possible lines between Ca and Fe. It is clear that the X-ray emitting and optically-emitting gas are probing different regions of the ejecta. Only with a complete characterization of all of the ejecta can a meaningful comparison to nucleosynthesis models be made and conclusions drawn about

  14. HIV-AIDS Connection

    MedlinePlus

    ... Marketing Share this: Main Content Area The HIV-AIDS Connection AIDS was first recognized in 1981 and ... is there overwhelming scientific consensus that HIV causes AIDS? Before HIV infection became widespread in the human ...

  15. Heart attack first aid

    MedlinePlus

    First aid - heart attack; First aid - cardiopulmonary arrest; First aid - cardiac arrest ... of patients with unstable angina/non-ST-elevation myocardial infarction (updating the 2007 guideline and replacing the 2011 ...

  16. Splinter, First Aid

    MedlinePlus

    ... and rashes clinical tools newsletter | contact Share | Splinter, First Aid A A A First Aid for Splinter: View ... wet, it makes the area prone to infection. First Aid Guide Self-care measures to remove a splinter ...

  17. Performance of a novel LED lamp arrangement to reduce SNR fluctuation for multi-user visible light communication systems.

    PubMed

    Wang, Zixiong; Yu, Changyuan; Zhong, Wen-De; Chen, Jian; Chen, Wei

    2012-02-13

    This paper investigates the performance of our recently proposed LED lamp arrangement to reduce the SNR fluctuation from different locations in the room for multi-user visible light communications. The LED lamp arrangement consists of 4 LED lamps positioned in the corners and 12 LED lamps spread evenly on a circle. Our studies show that the SNR fluctuation under such a LED lamp arrangement is reduced from 14.5 dB to 0.9 dB, which guarantees that users can obtain almost identical communication quality, regardless of their locations. After time domain zero-forcing (ZF) equalization, the BER performances and channel capacities of 100-Mbit/s and 200-Mbit/s bipolar on-off-keying (OOK) signal with most significant inter-symbol interference (ISI) are very close to that of the channel without any ISI caused by this LED lamp arrangement.

  18. Observations of the radio source G6.6-0.1 positionally coincident with the W28 SNR

    NASA Technical Reports Server (NTRS)

    Andrews, M. D.; Basart, J. P.; Lamb, R. C.

    1985-01-01

    This paper reports scaled-array continuum and H76-alpha line observations of the radio source G6.6-0.1 which is positioned at the center of the W28 SNR. The source exhibits a bright core surrounded by extended emission which appears organized into arcs and wisps. G6.6-0.1 is interpreted as a compact H II region with a unique morphology.

  19. Performance of the split-symbol moments SNR estimator in the presence of inter-symbol interference

    NASA Technical Reports Server (NTRS)

    Shah, B.; Hinedi, S.

    1989-01-01

    The Split-Symbol Moments Estimator (SSME) is an algorithm that is designed to estimate symbol signal-to-noise ratio (SNR) in the presence of additive white Gaussian noise (AWGN). The performance of the SSME algorithm in band-limited channels is examined. The effects of the resulting inter-symbol interference (ISI) are quantified. All results obtained are in closed form and can be easily evaluated numerically for performance prediction purposes. Furthermore, they are validated through digital simulations.

  20. Star Forming Dense Cloud Cores in the TeV -ray SNR RX J1713.7-3946

    SciTech Connect

    Sano, H.; Sato, J.; Yamamoto, H.; Hayakawa, T.; Torii, K.; Moribe, N.; Kawamura, A.; Okuda, T.; Mizuno, N.; Onishi, T.; Maezawa, H.; Inoue, T.; Inutsuka, S.; Tanaka, T.; Mizuno, A.; Ogawa, H.; Stutzki, J.; Bertoldi, F.; Anderl, S.; Bronfman, L.; Koo, B.C.

    2010-10-27

    RX J1713.7-3946 is one of the TeV {gamma}-ray supernova remnants (SNRs) emitting synchrotron X rays. The SNR is associated with molecular gas located at {approx}1 kpc. We made new molecular observations toward the dense cloud cores, peaks A, C and D, in the SNR in the {sup 12}CO(J=2-1) and {sup 13}CO(J=2-1) transitions at angular resolution of 90 degrees. The most intense core in {sup 13}CO, peak C, was also mapped in the {sup 12}CO(J=4-3) transition at angular resolution of 38 degrees. Peak C shows strong signs of active star formation including bipolar outflow and a far-infrared protostellar source and has a steep gradient with a r{sup -2.2 {+-} 0.4} variation in the average density within radius r. Peak C and the other dense cloud cores are rim-brightened in synchrotron X rays, suggesting that the dense cloud cores are embedded within or on the outer boundary of the SNR shell. This confirms the earlier suggestion that the X rays are physically associated with the molecular gas (Fukui et al. 2003). We present a scenario where the densest molecular core, peak C, survived against the blast wave and is now embedded within the SNR. Numerical simulations of the shock-cloud interaction indicate that a dense clump can indeed survive shock erosion, since shock propagation speed is stalled in the dense clump. Additionally, the shock-cloud interaction induces turbulence and magnetic field amplification around the dense clump that may facilitate particle acceleration in the lower-density inter-clump space leading to the enhanced synchrotron X rays around dense cores.

  1. Clinical NECR in 18F-FDG PET scans: optimization of injected activity and variable acquisition time. Relationship with SNR

    NASA Astrophysics Data System (ADS)

    Carlier, T.; Ferrer, L.; Necib, H.; Bodet-Milin, C.; Rousseau, C.; Kraeber-Bodéré, F.

    2014-10-01

    The injected activity and the acquisition time per bed position for 18F-FDG PET scans are usually optimized by using metrics obtained from phantom experiments. However, optimal activity and time duration can significantly vary from a phantom set-up and from patient to patient. An approach using a patient-specific noise equivalent count rate (NECR) modelling has been previously proposed for optimizing clinical scanning protocols. We propose using the clinical NECR on a large population as a function of the body mass index (BMI) for deriving the optimal injected activity and acquisition duration per bed position. The relationship between the NEC and the signal-to-noise ratio (SNR) was assessed both in a phantom and in a clinical setting. 491 consecutive patients were retrospectively evaluated and divided into 4 BMI subgroups. Two criteria were used to optimize the injected activity and the time per bed position was adjusted using the NECR value while keeping the total acquisition time constant. Finally, the relationship between NEC and SNR was investigated using an anthropomorphic phantom and a population of 507 other patients. While the first dose regimen suggested a unique injected activity (665 MBq) regardless of the BMI, the second dose regimen proposed a variable activity and a total acquisition time according to the BMI. The NEC improvement was around 35% as compared with the local current injection rule. Variable time per bed position was derived according to BMI and anatomical region. NEC and number of true events were found to be highly correlated with SNR for the phantom set-up and partially confirmed in the patient study for the BMI subgroup under 28 kg m-2 suggesting that for the scanner, the nonlinear reconstruction algorithm used in this study and BMI < 28 kg m-2, NEC, or the number of true events linearly correlated with SNR2.

  2. High-speed and high-SNR photoacoustic microscopy based on a galvanometer mirror in non-conducting liquid

    NASA Astrophysics Data System (ADS)

    Kim, Jin Young; Lee, Changho; Park, Kyungjin; Han, Sangyeob; Kim, Chulhong

    2016-10-01

    Optical-resolution photoacoustic microscopy (OR-PAM), a promising microscopic imaging technique with high ultrasound resolution and superior optical sensitivity, can provide anatomical, functional, and molecular information at scales ranging from the microvasculature to single red blood cells. In particular, real-time OR-PAM imaging with a high signal-to-noise ratio (SNR) is a prerequisite for widespread use in preclinical and clinical applications. Although several technical approaches have been pursued to simultaneously improve the imaging speed and SNR of OR-PAM, they are bulky, complex, not sensitive, and/or not actually real-time. In this paper, we demonstrate a simple and novel OR-PAM technique which is based on a typical galvanometer immersed in non-conducting liquid. Using an opto-ultrasound combiner, this OR-PAM system achieves a high SNR and fast imaging speed. It takes only 2 seconds to acquire a volumetric image with a wide field of view (FOV) of 4 × 8 mm2 along the X and Y axes, respectively. The measured lateral and axial resolutions are 6.0 and 37.7 μm, respectively. Finally, as a demonstration of the system’s capability, we successfully imaged the microvasculature in a mouse ear in vivo. Our new method will contribute substantially to the popularization and commercialization of OR-PAM in various preclinical and clinical applications.

  3. High-speed and high-SNR photoacoustic microscopy based on a galvanometer mirror in non-conducting liquid

    PubMed Central

    Kim, Jin Young; Lee, Changho; Park, Kyungjin; Han, Sangyeob; Kim, Chulhong

    2016-01-01

    Optical-resolution photoacoustic microscopy (OR-PAM), a promising microscopic imaging technique with high ultrasound resolution and superior optical sensitivity, can provide anatomical, functional, and molecular information at scales ranging from the microvasculature to single red blood cells. In particular, real-time OR-PAM imaging with a high signal-to-noise ratio (SNR) is a prerequisite for widespread use in preclinical and clinical applications. Although several technical approaches have been pursued to simultaneously improve the imaging speed and SNR of OR-PAM, they are bulky, complex, not sensitive, and/or not actually real-time. In this paper, we demonstrate a simple and novel OR-PAM technique which is based on a typical galvanometer immersed in non-conducting liquid. Using an opto-ultrasound combiner, this OR-PAM system achieves a high SNR and fast imaging speed. It takes only 2 seconds to acquire a volumetric image with a wide field of view (FOV) of 4 × 8 mm2 along the X and Y axes, respectively. The measured lateral and axial resolutions are 6.0 and 37.7 μm, respectively. Finally, as a demonstration of the system’s capability, we successfully imaged the microvasculature in a mouse ear in vivo. Our new method will contribute substantially to the popularization and commercialization of OR-PAM in various preclinical and clinical applications. PMID:27708379

  4. Monitoring of the volcanic plume based on the post-fit phase residual of PPP analysis and SNR data

    NASA Astrophysics Data System (ADS)

    Ohta, Yusaku; Iguchi, Masato

    2016-04-01

    A volcanic explosion is one of the largest energy-release phenomena on earth. For example, vulcanian eruptions usually eject large amounts of rock mass, tephra, and volcanic ash. Ash fall from such events can seriously affect the structural integrity of buildings, in addition to disrupting land and air traffic. Therefore, the monitoring and prediction of ash fall is very important. In this study, using data from a dense GNSS network, we investigated the spatiotemporal development of the volcanic plume ejected by the vulcanian eruption in Sakurajima, southwestern Japan on July 24, 2012. We extracted the post-fit phase residuals (PPR) of ionosphere-free linear combinations for each satellite based on the precise point positioning approach. Temporal and spatial PPR anomalies clearly detected the movement of the volcanic plume. The maximum height of the crossing points of anomalous PPR paths was determined to be approximately 4000 m. We then compared the PPR with the signal-to-noise ratio (SNR) anomalies. Only the path passing just above the crater showed significant change in the SNR value, suggesting that the volcanic ash and the water vapor within the volcanic plume became separated after reaching a high altitude because of ash fall during the plume's lateral movement. In the presentation, we will introduce the eruption in Shin-dake (Kuchinoerabu island, southwestern Japan) on May 29, 2015 based on the SNR data.

  5. SPATIAL DISTRIBUTION OF X-RAY EMITTING EJECTA IN TYCHO’S SNR: INDICATIONS OF SHOCKED TITANIUM

    SciTech Connect

    Miceli, M.; Sciortino, S.; Orlando, S.; Troja, E.

    2015-06-01

    Young supernova remnants (SNRs) show characteristic ejecta-dominated X-ray emission that allows us to probe the products of explosive nucleosynthesis processes and to ascertain important information about the physics of supernova explosions. Hard X-ray observations have recently revealed the presence of the radioactive decay lines of {sup 44}Ti at ∼67.9 and ∼78.4 keV in Tycho’s SNR. Here, we analyze a set of XMM-Newton archive observations of Tycho’s SNR. We produce equivalent width (EW) maps of the Fe K and Ca xix emission lines and find indications for a stratification of the abundances of these elements and significant anisotropies. We then perform spatially resolved spectral analysis by identifying five different regions characterized by high/low values of the Fe K EW. We find that the spatial distribution of the Fe K emission is correlated with that of Cr xxii. We also detect the Ti K line complex in the spectra extracted from the two regions with the highest values of Fe and Cr EWs. The Ti line emission remains undetected in regions where Fe and Cr EWs are low. Our results indicate that the post-shock Ti is spatially colocated with other iron-peak nuclei in Tycho’s SNR, in agreement with the predictions of multi-D models of SNe Ia.

  6. Yet another plasma diagnostic with He-like triplet: Probing energetic electrons behind SNR shocks with ASTRO-H SXS

    NASA Astrophysics Data System (ADS)

    Sawada, Makoto; Kaastra, Jelle

    We present a new X-ray line diagnostic to probe energetic electrons behind SNR shocks. SNR shocks are believed to be acceleration sites of the Galactic cosmic rays up to knee energy. In the early stage of acceleration, particles must have sufficient energies to cross the shock to enter diffusive shock acceleration. This requires supra-thermal energies for electrons, however, we currently do not know how electrons depart from the thermal pool to attain such energies. Hence observational constraints on the amount and energy distribution of supra-thermal electrons are awaited. Here we propose a new X-ray line diagnostic using the He-like triplet to detect and characterise the energy distribution of supra-thermal electrons. We simulate X-ray spectra of SNR plasma interacting with energetic electrons and find that the forbidden line of the He-like triplet is enhanced via inner-shell ionisation process of Li-like ions. Such an effect can be precisely measured by high-resolution spectroscopy with the coming ASTRO-H SXS instrument.

  7. U17/snR30 is a ubiquitous snoRNA with two conserved sequence motifs essential for 18S rRNA production.

    PubMed

    Atzorn, Vera; Fragapane, Paola; Kiss, Tamás

    2004-02-01

    Saccharomyces cerevisiae snR30 is an essential box H/ACA small nucleolar RNA (snoRNA) required for the processing of 18S rRNA. Here, we show that the previously characterized human, reptilian, amphibian, and fish U17 snoRNAs represent the vertebrate homologues of yeast snR30. We also demonstrate that U17/snR30 is present in the fission yeast Schizosaccharomyces pombe and the unicellular ciliated protozoan Tetrahymena thermophila. Evolutionary comparison revealed that the 3'-terminal hairpins of U17/snR30 snoRNAs contain two highly conserved sequence motifs, the m1 (AUAUUCCUA) and m2 (AAACCAU) elements. Mutation analysis of yeast snR30 demonstrated that the m1 and m2 elements are essential for early cleavages of the 35S pre-rRNA and, consequently, for the production of mature 18S rRNA. The m1 and m2 motifs occupy the opposite strands of an internal loop structure, and they are located invariantly 7 nucleotides upstream from the ACA box of U17/snR30 snoRNAs. U17/snR30 is the first identified box H/ACA snoRNA that possesses an evolutionarily conserved role in the nucleolytic processing of eukaryotic pre-rRNA.

  8. Cardiac output during human sleep.

    PubMed

    Miller, J C; Horvath, S M

    1976-10-01

    Impedance cardiogram and sleep EEG were recorded from four male and four female subjects, aged 21 to 22 years, during one night in the laboratory following one adaptation night. Cardiac output fell approximately 26% during the night as a consequence of diminished stroke volume, the lowest values of both occurring during the latter portion of the night, dominated by SREM (rapid-eye-movement stage). Intracycle comparisons between SREM and SWS (slow wave sleep) or between eye movement burst and non-burst SREM showed no significant differences in stroke volume or cardiac output. Pre-ejection period and systolic ejection period were measured and discussed. The non-coincidence of the nadir of metabolic activity, expressed as cardiac output, and the apex of slow-wave sleep activity supported the concept of slow-wave sleep as a period of physiological restoration.

  9. Input/output error analyzer

    NASA Technical Reports Server (NTRS)

    Vaughan, E. T.

    1977-01-01

    Program aids in equipment assessment. Independent assembly-language utility program is designed to operate under level 27 or 31 of EXEC 8 Operating System. It scans user-selected portions of system log file, whether located on tape or mass storage, and searches for and processes 1/0 error (type 6) entries.

  10. EPIC Study of Two Enigmatic Sources: The Mouse and SNR 359.1-0.5

    NASA Technical Reports Server (NTRS)

    Pavlov, George

    2004-01-01

    The objective of the original proposal was to observe the Mouse pulsar wind nebula (associated with PSR J1744-2958) and the nearby supernova remnant G359.1-0.5, where the pulsar was probably born, with the XMM-Newton observatory to study the properties of these objects. SNR G359.1-0.5 was accepted as a Category C target and has not been observed. The Mouse was observed on April 27,2003 for 52 ks. The image analysis has shown that the Mouse is extended in the East-West direction, possibly along the direction of the pulsar's proper motion. The spectrum of this pulsar wind nebula can be described as an absorbed power law with the photon index GAMMA = 1.9 plus or minus 0.1, effective hydrogen column density n(sub H) = (2.6 plus or minus 0.1) x 10(exp 22) per square centimeter, and flux F = 1.8 x 10(exp -11) erg per square centimeter per second in the 1-10 keV energy range. Based on the n(sub H) value, the distance to the source is about 5 kpc, which results in the luminosity 3.7 x 10(exp 34) erg per second. We conclude that PSR J1744-2958 and the Mouse are not physically associated with G359.1-0.5, which lies at a larger distance. In addition to the Mouse, we also detected two Low-Mass X-ray Binaries, SLX 1744-299 and 1744-300, in the EPIC MOS and PN fields of view. The latter of these objects showed a Type I X-ray burst during our observation, with a rise time of 5 s and decay time of 60 s. A very strong pileup during the burst made the analysis of the burst properties unreliable. The spectral analysis of the persistent radiation from SLX 1744-299 and 1744-300 yields the hydrogen column densities of 3.2 plus or minus 0.1 and (3.6 plus or minus 0.2) x 10(exp 22) per square centimeter, respectively, which suggests that the sources are close to the Galactic center (d = 8-9 kpc). The spectra can be reasonably well fitted with a blackbody plus thin disk model, with the blackbody temperatures of 1.7 plus or minus 0.2 and 1.8 plus or minus 0.2 keV, respectively.

  11. World Input-Output Network

    PubMed Central

    Cerina, Federica; Zhu, Zhen; Chessa, Alessandro; Riccaboni, Massimo

    2015-01-01

    Production systems, traditionally analyzed as almost independent national systems, are increasingly connected on a global scale. Only recently becoming available, the World Input-Output Database (WIOD) is one of the first efforts to construct the global multi-regional input-output (GMRIO) tables. By viewing the world input-output system as an interdependent network where the nodes are the individual industries in different economies and the edges are the monetary goods flows between industries, we analyze respectively the global, regional, and local network properties of the so-called world input-output network (WION) and document its evolution over time. At global level, we find that the industries are highly but asymmetrically connected, which implies that micro shocks can lead to macro fluctuations. At regional level, we find that the world production is still operated nationally or at most regionally as the communities detected are either individual economies or geographically well defined regions. Finally, at local level, for each industry we compare the network-based measures with the traditional methods of backward linkages. We find that the network-based measures such as PageRank centrality and community coreness measure can give valuable insights into identifying the key industries. PMID:26222389

  12. Compact Circuit Preprocesses Accelerometer Output

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr.

    1993-01-01

    Compact electronic circuit transfers dc power to, and preprocesses ac output of, accelerometer and associated preamplifier. Incorporated into accelerometer case during initial fabrication or retrofit onto commercial accelerometer. Made of commercial integrated circuits and other conventional components; made smaller by use of micrologic and surface-mount technology.

  13. World Input-Output Network.

    PubMed

    Cerina, Federica; Zhu, Zhen; Chessa, Alessandro; Riccaboni, Massimo

    2015-01-01

    Production systems, traditionally analyzed as almost independent national systems, are increasingly connected on a global scale. Only recently becoming available, the World Input-Output Database (WIOD) is one of the first efforts to construct the global multi-regional input-output (GMRIO) tables. By viewing the world input-output system as an interdependent network where the nodes are the individual industries in different economies and the edges are the monetary goods flows between industries, we analyze respectively the global, regional, and local network properties of the so-called world input-output network (WION) and document its evolution over time. At global level, we find that the industries are highly but asymmetrically connected, which implies that micro shocks can lead to macro fluctuations. At regional level, we find that the world production is still operated nationally or at most regionally as the communities detected are either individual economies or geographically well defined regions. Finally, at local level, for each industry we compare the network-based measures with the traditional methods of backward linkages. We find that the network-based measures such as PageRank centrality and community coreness measure can give valuable insights into identifying the key industries. PMID:26222389

  14. Input/output interface module

    NASA Technical Reports Server (NTRS)

    Ozyazici, E. M.

    1980-01-01

    Module detects level changes in any of its 16 inputs, transfers changes to its outputs, and generates interrupts when changes are detected. Up to four changes-in-state per line are stored for later retrieval by controlling computer. Using standard TTL logic, module fits 19-inch rack-mounted console.

  15. Classroom Interaction and Language Output

    ERIC Educational Resources Information Center

    Wang, Qiaoying; Castro, Carolyn D.

    2010-01-01

    This study investigates the effects of classroom interactions between a) students and students and b) students and teachers on the learning of English passivization by L1 Chinese adult learners of English as a foreign language during the language input and output treatments. In phase 1, both groups were asked to read and underline the input…

  16. World Input-Output Network.

    PubMed

    Cerina, Federica; Zhu, Zhen; Chessa, Alessandro; Riccaboni, Massimo

    2015-01-01

    Production systems, traditionally analyzed as almost independent national systems, are increasingly connected on a global scale. Only recently becoming available, the World Input-Output Database (WIOD) is one of the first efforts to construct the global multi-regional input-output (GMRIO) tables. By viewing the world input-output system as an interdependent network where the nodes are the individual industries in different economies and the edges are the monetary goods flows between industries, we analyze respectively the global, regional, and local network properties of the so-called world input-output network (WION) and document its evolution over time. At global level, we find that the industries are highly but asymmetrically connected, which implies that micro shocks can lead to macro fluctuations. At regional level, we find that the world production is still operated nationally or at most regionally as the communities detected are either individual economies or geographically well defined regions. Finally, at local level, for each industry we compare the network-based measures with the traditional methods of backward linkages. We find that the network-based measures such as PageRank centrality and community coreness measure can give valuable insights into identifying the key industries.

  17. Speech Auditory Brainstem Response through hearing aid stimulation.

    PubMed

    Bellier, Ludovic; Veuillet, Evelyne; Vesson, Jean-François; Bouchet, Patrick; Caclin, Anne; Thai-Van, Hung

    2015-07-01

    Millions of people across the world are hearing impaired, and rely on hearing aids to improve their everyday life. Objective audiometry could optimize hearing aid fitting, and is of particular interest for non-communicative patients. Speech Auditory Brainstem Response (speech ABR), a fine electrophysiological marker of speech encoding, is presently seen as a promising candidate for implementing objective audiometry; yet, unlike lower-frequency auditory-evoked potentials (AEPs) such as cortical AEPs or auditory steady-state responses (ASSRs), aided-speech ABRs (i.e., speech ABRs through hearing aid stimulation) have almost never been recorded. This may be due to their high-frequency components requesting a high temporal precision of the stimulation. We assess here a new approach to record high-quality and artifact-free speech ABR while stimulating directly through hearing aids. In 4 normal-hearing adults, we recorded speech ABR evoked by a /ba/ syllable binaurally delivered through insert earphones for quality control or through hearing aids. To assess the presence of a potential stimulus artifact, recordings were also done in mute conditions with the exact same potential sources of stimulus artifacts as in the main runs. Hearing aid stimulation led to artifact-free speech ABR in each participant, with the same quality as when using insert earphones, as shown with signal-to-noise (SNR) measurements. Our new approach consisting in directly transmitting speech stimuli through hearing aids allowed for a perfect temporal precision mandatory in speech ABR recordings, and could thus constitute a decisive step in hearing impairment investigation and in hearing aid fitting improvement.

  18. The Master Hearing Aid

    PubMed Central

    Curran, James R.

    2013-01-01

    As early as the 1930s the term Master Hearing Aid (MHA) described a device used in the fitting of hearing aids. In their original form, the MHA was a desktop system that allowed for simulated or actual adjustment of hearing aid components that resulted in a changed hearing aid response. Over the years the MHA saw many embodiments and contributed to a number of rationales for the fitting of hearing aids. During these same years, the MHA was viewed by many as an inappropriate means of demonstrating hearing aids; the audio quality of the desktop systems was often superior to the hearing aids themselves. These opinions and the evolution of the MHA have molded the modern perception of hearing aids and the techniques used in the fitting of hearing aids. This article reports on a history of the MHA and its influence on the fitting of hearing aids. PMID:23686682

  19. Cortical Auditory Evoked Potentials in (Un)aided Normal-Hearing and Hearing-Impaired Adults.

    PubMed

    Van Dun, Bram; Kania, Anna; Dillon, Harvey

    2016-02-01

    Cortical auditory evoked potentials (CAEPs) are influenced by the characteristics of the stimulus, including level and hearing aid gain. Previous studies have measured CAEPs aided and unaided in individuals with normal hearing. There is a significant difference between providing amplification to a person with normal hearing and a person with hearing loss. This study investigated this difference and the effects of stimulus signal-to-noise ratio (SNR) and audibility on the CAEP amplitude in a population with hearing loss. Twelve normal-hearing participants and 12 participants with a hearing loss participated in this study. Three speech sounds-/m/, /g/, and /t/-were presented in the free field. Unaided stimuli were presented at 55, 65, and 75 dB sound pressure level (SPL) and aided stimuli at 55 dB SPL with three different gains in steps of 10 dB. CAEPs were recorded and their amplitudes analyzed. Stimulus SNRs and audibility were determined. No significant effect of stimulus level or hearing aid gain was found in normal hearers. Conversely, a significant effect was found in hearing-impaired individuals. Audibility of the signal, which in some cases is determined by the signal level relative to threshold and in other cases by the SNR, is the dominant factor explaining changes in CAEP amplitude. CAEPs can potentially be used to assess the effects of hearing aid gain in hearing-impaired users. PMID:27587919

  20. Microgyroscope with closed loop output

    NASA Technical Reports Server (NTRS)

    Challoner, A. Dorian (Inventor); Gutierrez, Roman C. (Inventor); Tang, Tony K. (Inventor); Cargille, Donald R. (Inventor)

    2002-01-01

    A micro-gyroscope (10) having closed loop operation by a control voltage (V.sub.TY), that is demodulated by an output signal of the sense electrodes (S1, S2), providing Coriolis torque rebalance to prevent displacement of the micro-gyroscope (10) on the output axis (y-axis). The present invention provides wide-band, closed-loop operation for a micro-gyroscope (10) and allows the drive frequency to be closely tuned to a high Q sense axis resonance. A differential sense signal (S1-S2) is compensated and fed back by differentially changing the voltage on the drive electrodes to rebalance Coriolis torque. The feedback signal is demodulated in phase with the drive axis signal (K.sub..omega..crclbar..sub.x) to produce a measure of the Coriolis force.

  1. Standardized multiple output power supply

    NASA Technical Reports Server (NTRS)

    Ragusa, E. V.

    1975-01-01

    A comprehensive program to develop a prototype model of a standardized multiple output power supply for use in space flight applications is described. The prototype unit was tested and evaluated to assure that the design would provide near optimum performance for the planned application. The prototype design used a dc-to-dc converter incorporating reqenerative current feedback with a time-ratio controlled duty cycle to achieve high efficiency over a wide variation of input voltage and output loads. The packaging concept uses a mainframe capable of accommodating up to four inverter/regulator modules with one common input filter and housekeeping module. Each inverter/regulator module provides a maximum of 100 watts or 10 amperes. Each module is adaptable to operate at any voltage between 4.0 volts and 108 volts. The prototype unit contains +5, + or - 15 and +28 volt modules.

  2. UFO - The Universal FEYNRULES Output

    NASA Astrophysics Data System (ADS)

    Degrande, Céline; Duhr, Claude; Fuks, Benjamin; Grellscheid, David; Mattelaer, Olivier; Reiter, Thomas

    2012-06-01

    We present a new model format for automatized matrix-element generators, the so-called Universal FEYNRULES Output (UFO). The format is universal in the sense that it features compatibility with more than one single generator and is designed to be flexible, modular and agnostic of any assumption such as the number of particles or the color and Lorentz structures appearing in the interaction vertices. Unlike other model formats where text files need to be parsed, the information on the model is encoded into a PYTHON module that can easily be linked to other computer codes. We then describe an interface for the MATHEMATICA package FEYNRULES that allows for an automatic output of models in the UFO format.

  3. Output gear of automatic transmission

    SciTech Connect

    Ideta, Y.; Miida, S.

    1986-12-16

    An automatic transmission is described for a front engine, front wheel drive vehicle, comprising: a torque converter; a main power train comprising a rotatory terminal member, the main power train being connected with the torque converter for transmitting a driving torque from the torque converter to the terminal member; housing means enclosing the main power train, the housing means having a cylindrical bore and at least one oil feed passage opening in a cylindrical surface of the bore, and an output gear rotatably supported by the housing means and connected detachably with the terminal member of the main power train for transmitting the driving torque from the main power train to front wheels of the vehicle. The main power train is placed between the torque converter and the output gear, the output gear having a hub which is splined detachably to the terminal member, and which is fitting in the bore of the housing means in such a manner that the hub can rotate in the bore. The hub has an annular groove formed on an outer cylindrical surface of the hub, the output gear being formed with lubricating means extending from the annular groove for conveying oil from the annular groove, the oil feed passage of the housing means opening into the annular groove for supplying oil into the lubricating means through the annular groove. The annular groove has sufficient depth and width within a range permitted by a strength of the hub to prevent a shortage of the oil supply through the annular groove to the lubricating means due to a centrifugal force of the oil rotating in the annular groove together with walls of the annular groove.

  4. Combining parallel detection of proton echo planar spectroscopic imaging (PEPSI) measurements with a data-consistency constraint improves SNR.

    PubMed

    Tsai, Shang-Yueh; Hsu, Yi-Cheng; Chu, Ying-Hua; Kuo, Wen-Jui; Lin, Fa-Hsuan

    2015-12-01

    One major challenge of MRSI is the poor signal-to-noise ratio (SNR), which can be improved by using a surface coil array. Here we propose to exploit the spatial sensitivity of different channels of a coil array to enforce the k-space data consistency (DC) in order to suppress noise and consequently to improve MRSI SNR. MRSI data were collected using a proton echo planar spectroscopic imaging (PEPSI) sequence at 3 T using a 32-channel coil array and were averaged with one, two and eight measurements (avg-1, avg-2 and avg-8). The DC constraint was applied using a regularization parameter λ of 1, 2, 3, 5 or 10. Metabolite concentrations were quantified using LCModel. Our results show that the suppression of noise by applying the DC constraint to PEPSI reconstruction yields up to 32% and 27% SNR gain for avg-1 and avg-2 data with λ = 5, respectively. According to the reported Cramer-Rao lower bounds, the improvement in metabolic fitting was significant (p < 0.01) when the DC constraint was applied with λ ≥ 2. Using the DC constraint with λ = 3 or 5 can minimize both root-mean-square errors and spatial variation for all subjects using the avg-8 data set as reference values. Our results suggest that MRSI reconstructed with a DC constraint can save around 70% of scanning time to obtain images and spectra with similar SNRs using λ = 5.

  5. THE PROGENITOR OF THE TYPE Ia SUPERNOVA THAT CREATED SNR 0519-69.0 IN THE LARGE MAGELLANIC CLOUD

    SciTech Connect

    Edwards, Zachary I.; Pagnotta, Ashley; Schaefer, Bradley E.

    2012-03-10

    Models for the progenitor systems of Type Ia supernovae can be divided into double-degenerate systems, which contain two white dwarfs, and single-degenerate systems, which contain one white dwarf plus one companion star (either a red giant, a subgiant, or a >1.16 M{sub Sun} main-sequence star). The white dwarf is destroyed in the supernova explosion, but any non-degenerate companion remains intact. We present the results of a search for an ex-companion star in SNR 0519-69.0, located in the Large Magellanic Cloud, based on images taken with the Hubble Space Telescope with a limiting magnitude of V = 26.05. SNR 0519-69.0 is confidently known to be from a Type Ia supernova based on its light echoes and X-ray spectra. The geometric center of the remnant (based on the H{alpha} and X-ray shell) is at 05:19:34.83, -69:02:06.92 (J2000). Accounting for the measurement uncertainties, the orbital velocity, and the kick velocity, any ex-companion star must be within 4.''7 of this position at the 99.73% confidence level. This circle contains 27 main-sequence stars brighter than V = 22.7, any one of which could be the ex-companion star left over from a supersoft source progenitor system. The circle contains no post-main-sequence stars, and this rules out the possibility of all other published single-degenerate progenitor classes (including symbiotic stars, recurrent novae, helium donors, and the spin-up/spin-down models) for this particular supernova. The only remaining possibility is that SNR 0519-69.0 was formed from either a supersoft source or a double-degenerate progenitor system.

  6. Timing considerations for preclinical MRgRT: effects of ion diffusion, SNR and imaging times on FXG gel calibration

    NASA Astrophysics Data System (ADS)

    Welch, M.; Foltz, W. D.; Jaffray, D. A.

    2015-01-01

    Sub-millimeter resolution images are required for gel dosimeters to be used in preclinical research, which is challenging for MR probed ferrous xylenol-orange (FXG) dosimeters due to ion diffusion and inadequate SNR. A preclinical 7 T MR, small animal irradiator and FXG dosimeters were used in all experiments. Ion diffusion was analyzed using high resolution (0.2 mm/pixel) T1 MR images collected every 5 minutes, post-irradiation, for an hour. Using Fick's second law, ion diffusion was approximated for the first hour post-irradiation. SNR, T1 map precision and calibration fit were determined for two MR protocols: (1) 10 minute acquisition, 0.35mm/pixel and 3mm slices, (2) 45 minute acquisition, 0. 25 mm/pixel and 2 mm slices. SNR and T1 map precision were calculated using a Monte Carlo simulation. Calibration curves were determined by plotting R1 relaxation rates versus depth dose data, and fitting a linear trend line. Ion diffusion was estimated as 0.003mm2 in the first hour post-irradiation. For protocols (1) and (2) respectively, Monte Carlo simulation predicted T1 precisions of 3% and 5% within individual voxels using experimental SNRs; the corresponding measured T1 precisions were 8% and 12%. The linear trend lines reported slopes of 27 ± 3 Gy*s (R2: 0.80 ± 0.04) and 27 ± 4 Gy*s (R2: 0.90 ± 0.04). Ion diffusion is negligible within the first hour post-irradiation, and an accurate and reproducible calibration can be achieved in a preclinical setting with sub-millimeter resolution.

  7. Combining parallel detection of proton echo planar spectroscopic imaging (PEPSI) measurements with a data-consistency constraint improves SNR.

    PubMed

    Tsai, Shang-Yueh; Hsu, Yi-Cheng; Chu, Ying-Hua; Kuo, Wen-Jui; Lin, Fa-Hsuan

    2015-12-01

    One major challenge of MRSI is the poor signal-to-noise ratio (SNR), which can be improved by using a surface coil array. Here we propose to exploit the spatial sensitivity of different channels of a coil array to enforce the k-space data consistency (DC) in order to suppress noise and consequently to improve MRSI SNR. MRSI data were collected using a proton echo planar spectroscopic imaging (PEPSI) sequence at 3 T using a 32-channel coil array and were averaged with one, two and eight measurements (avg-1, avg-2 and avg-8). The DC constraint was applied using a regularization parameter λ of 1, 2, 3, 5 or 10. Metabolite concentrations were quantified using LCModel. Our results show that the suppression of noise by applying the DC constraint to PEPSI reconstruction yields up to 32% and 27% SNR gain for avg-1 and avg-2 data with λ = 5, respectively. According to the reported Cramer-Rao lower bounds, the improvement in metabolic fitting was significant (p < 0.01) when the DC constraint was applied with λ ≥ 2. Using the DC constraint with λ = 3 or 5 can minimize both root-mean-square errors and spatial variation for all subjects using the avg-8 data set as reference values. Our results suggest that MRSI reconstructed with a DC constraint can save around 70% of scanning time to obtain images and spectra with similar SNRs using λ = 5. PMID:26484749

  8. Effects of Synthetic Speech Output and Orthographic Feedback on Spelling in a Student with Autism: A Preliminary Study.

    ERIC Educational Resources Information Center

    Schlosser, Ralf W.; Blischak, Doreen M.; Belfiore, Phillip J.; Bartley, Clair; Barnett, Nanette

    1998-01-01

    A nonspeaking student (age 10) with autism was taught to spell words under three feedback conditions using a voice output communication aid. Results found that the provision of speech output alone and in combination with orthographic feedback resulted in more efficient spelling than the provision of orthographic feedback alone. (Author/CR)

  9. The Effects of Speech Output Technology on Skill Acquisition in Children with Autism Spectrum Disorder: A Preliminary Investigation

    ERIC Educational Resources Information Center

    Torres-Viso, Mariana Siku

    2015-01-01

    Previous research on the use of voice output communication aids (VOCAs) has found a number of positive effects on the behavior of both the VOCA user and their communicative partners. Among these outcomes, studies have found that incorporating speech output into language learning tasks may result in faster and more efficient learning for adults…

  10. Answering the AIDS denialists: is AIDS real?

    PubMed

    Mirken, B

    2000-12-01

    This article looks at theories that say AIDS does not exist, or is not a new disease but only a collection of old ones--and explains some of the history behind earlier changes in the official definition of AIDS in the U.S., changes which caused some public confusion. PMID:12171004

  11. Input-output characterization of fiber reinforced composites by P waves

    NASA Technical Reports Server (NTRS)

    Renneisen, John D.; Williams, James H., Jr.

    1990-01-01

    Input-output characterization of fiber composites is studied theoretically by tracing P waves in the media. A new path motion to aid in the tracing of P and the reflection generated SV wave paths in the continuum plate is developed. A theoretical output voltage from the receiving transducer is calculated for a tone burst. The study enhances the quantitative and qualitative understanding of the nondestructive evaluation of fiber composites which can be modeled as transversely isotropic media.

  12. How HIV Causes AIDS

    MedlinePlus

    ... Share this: Main Content Area How HIV Causes AIDS HIV destroys CD4 positive (CD4+) T cells, which ... and disease, ultimately resulting in the development of AIDS. Most people who are infected with HIV can ...

  13. AIDS Myths and Misunderstandings

    MedlinePlus

    ... 21, 2014 Select a Language: Fact Sheet 158 AIDS Myths and Misunderstandings WHY ARE THERE SO MANY ... support this belief. Myth: Current medications can cure AIDS. It’s no big deal if you get infected. ...

  14. HIV/AIDS

    MedlinePlus

    ... at risk for serious infections and certain cancers. AIDS stands for acquired immunodeficiency syndrome. It is the final stage of infection with HIV. Not everyone with HIV develops AIDS. HIV most often spreads through unprotected sex with ...

  15. Students with AIDS.

    ERIC Educational Resources Information Center

    Broadwell, Cathy Allen; Strope, John L., Jr.

    1989-01-01

    Addresses the law as it pertains to Acquired Immune Deficiency Syndrome (AIDS) in public elementary and secondary schools. Section 504 of the Rehabilitation Act of 1973 has been used successfully in the majority of the AIDS cases discussed. (MLF)

  16. Unconsciousness - first aid

    MedlinePlus

    Loss of consciousness - first aid; Coma - first aid; Mental status change; Altered mental status ... person is unconscious and: Does not return to consciousness quickly (within a minute) Has fallen down or ...

  17. Frostbite, First Aid

    MedlinePlus

    ... and rashes clinical tools newsletter | contact Share | Frostbite, First Aid A A A Severe frostbite can result in ... became frozen). Frostbite is often associated with hypothermia. First Aid Guide In the case of mild frostbite, the ...

  18. Heat Exhaustion, First Aid

    MedlinePlus

    ... rashes clinical tools newsletter | contact Share | Heat Exhaustion, First Aid A A A Heat exhaustion signs and symptoms ... specific to the other stages of heat illness. First Aid Guide Use a combination of the following measures ...

  19. Heat Cramps, First Aid

    MedlinePlus

    ... rashes clinical tools newsletter | contact Share | Heat Cramps, First Aid A A A Heat cramp signs and symptoms ... if later stages of heat illness are suspected. First Aid Guide Use a combination of the following measures, ...

  20. Heatstroke, First Aid

    MedlinePlus

    ... and rashes clinical tools newsletter | contact Share | Heatstroke, First Aid A A A Heatstroke signs and symptoms can ... specific to the earlier stages of heat illness. First Aid Guide When heatstroke is suspected, seek emergency medical ...

  1. Bruises, First Aid

    MedlinePlus

    ... and rashes clinical tools newsletter | contact Share | Bruises, First Aid A A A Bruises lighten and change color ... Bruises can be a sign of internal bleeding. First Aid Guide If there is external bleeding in addition ...

  2. Tick Bites, First Aid

    MedlinePlus

    ... rashes clinical tools newsletter | contact Share | Tick Bites, First Aid A A A It is important to inspect ... temporary paralysis in their host (called tick paralysis). First Aid Guide To remove an embedded tick: Wash your ...

  3. First Aid: Influenza (Flu)

    MedlinePlus

    ... to Know About Zika & Pregnancy First Aid: The Flu KidsHealth > For Parents > First Aid: The Flu Print ... tiredness What to Do If Your Child Has Flu Symptoms: Call your doctor. Encourage rest. Keep your ...

  4. Young Remnants of Type Ia Supernovae and Their Progenitors: A Study of SNR G1.9+0.3

    NASA Astrophysics Data System (ADS)

    Chakraborti, Sayan; Childs, Francesca; Soderberg, Alicia

    2016-03-01

    SNe Ia, with their remarkably homogeneous light curves and spectra, have been used as standardizable candles to measure the accelerating expansion of the universe. Yet, their progenitors remain elusive. Common explanations invoke a degenerate star (white dwarf) that explodes upon almost reaching the Chandrasekhar limit, by either steadily accreting mass from a companion star or violently merging with another degenerate star. We show that circumstellar interaction in young Galactic supernova remnants can be used to distinguish between these single and double degenerate (DD) progenitor scenarios. Here we propose a new diagnostic, the surface brightness index, which can be computed from theory and compared with Chandra and Very Large Array (VLA) observations. We use this method to demonstrate that a DD progenitor can explain the decades-long flux rise and size increase of the youngest known galactic supernova remnant (SNR), G1.9+0.3. We disfavor a single degenerate scenario for SNR G1.9+0.3. We attribute the observed properties to the interaction between a steep ejecta profile and a constant density environment. We suggest using the upgraded VLA, ASKAP, and MeerKAT to detect circumstellar interaction in the remnants of historical SNe Ia in the Local Group of galaxies. This may settle the long-standing debate over their progenitors.

  5. DISCOVERY OF VERY HIGH ENERGY {gamma}-RAY EMISSION FROM THE SNR G54.1+0.3

    SciTech Connect

    Acciari, V. A.; Benbow, W.; Aliu, E.; Boltuch, D.; Arlen, T.; Aune, T.; Bautista, M.; Beilicke, M.; Buckley, J. H.; Bugaev, V.; Dickherber, R.; Bradbury, S. M.; Butt, Y.; Byrum, K.; Cesarini, A.; Ciupik, L.; Cui, W.; Finley, J. P.; Duke, C.; Finnegan, G. E-mail: wakely@uchicago.ed

    2010-08-10

    We report the discovery of very high energy (VHE) gamma-ray emission from the direction of the SNR G54.1+0.3 using the VERITAS ground-based gamma-ray observatory. The TeV signal has an overall significance of 6.8{sigma} and appears pointlike given the resolution of the instrument. The integral flux above 1 TeV is 2.5% of the Crab Nebula flux and significant emission is measured between 250 GeV and 4 TeV, well described by a power-law energy spectrum dN/dE {approx} E {sup -{Gamma}} with a photon index {Gamma} = 2.39 {+-} 0.23{sub stat} {+-} 0.30{sub sys}. We find no evidence of time variability among observations spanning almost two years. Based on the location, the morphology, the measured spectrum, the lack of variability, and a comparison with similar systems previously detected in the TeV band, the most likely counterpart of this new VHE gamma-ray source is the pulsar wind nebula (PWN) in the SNR G54.1+0.3. The measured X-ray to VHE gamma-ray luminosity ratio is the lowest among all the nebulae supposedly driven by young rotation-powered pulsars, which could indicate a particle-dominated PWN.

  6. Iterative Information-Reduced Carrier Synchronization Using Decision Feedback for Low SNR Applications

    NASA Astrophysics Data System (ADS)

    Simon, M. K.; Vilnrotter, V. A.

    1997-04-01

    Traditional methods for carrier synchronization of uncoded binary phase-shiftkeyed (BPSK) signals, e.g, conventional and polarity-type Costas loops, data-aided loops, demodulation{remodulation loops, etc., are obtained from approximations made to a closed-loop structure motivated by the maximum a posteriori (MAP) estimation of carrier phase. Inherent in all of these loops is the fact that their input data are assumed to be equiprobable (balanced) independent identically distributed (i.i.d.) binary sequences, and the MAP estimation loop from which these various structures are derived is predicated on this fact. The tracking performance limitation of such loops is the so-called squaring loss associated with the mean-squared phase error, which is the result of signal and noise products created by the necessity to remove the data modulation from the loop error signal. By reducing the amount of randomness (information) in the data that are input to the carrier synchronizer (hence the term information-reduced carrier synchronization), yet maintaining their i.i.d (but not necessarily balanced) property and also their independence of the additive noise, and then suitably modifying the synchronizer structure in accordance with this data reduction, one can obtain a significant squaring-loss improvement relative to what is achievable with the above-mentioned structures. One method for accomplishing this reduction in data randomness is through the use of decision feedback at the input of the loop structure, which should be contrasted with conventional structures such as the data-aided or polarity-type Costas loops that use decision feedback within the loop structure itself, and hence do not modify the structure based on the amount of information reduction achieved. While applying such a method to uncoded modulations will not satisfy the noise independence constraint on the modified data sequence (for reasons explained in the article), for coded modulations, we show that it is

  7. Late-Time Evolution of Composite Supernova Remnants: Deep Chandra Observations and Hydrodynamical Modeling of a Crushed Pulsar Wind Nebula in SNR G327.1-1.1

    NASA Technical Reports Server (NTRS)

    Temim, Tea; Slane, Patrick; Kolb, Christopher; Blondin, John; Hughes, John P.; Bucciantini, Niccolo

    2015-01-01

    In an effort to better understand the evolution of composite supernova remnants (SNRs) and the eventual fate of relativistic particles injected by their pulsars, we present a multifaceted investigation of the interaction between a pulsar wind nebula (PWN) and its host SNR G327.1-1.1. Our 350 ks Chandra X-ray observations of SNR G327.1-1.1 reveal a highly complex morphology; a cometary structure resembling a bow shock, prong-like features extending into large arcs in the SNR interior, and thermal emission from the SNR shell. Spectral analysis of the non-thermal emission offers clues about the origin of the PWN structures, while enhanced abundances in the PWN region provide evidence for mixing of supernova ejecta with PWN material. The overall morphology and spectral properties of the SNR suggest that the PWN has undergone an asymmetric interaction with the SNR reverse shock(RS) that can occur as a result of a density gradient in the ambient medium and or a moving pulsar that displaces the PWN from the center of the remnant. We present hydrodynamical simulations of G327.1-1.1 that show that its morphology and evolution can be described by a approx. 17,000 yr old composite SNR that expanded into a density gradient with an orientation perpendicular to the pulsar's motion. We also show that the RSPWN interaction scenario can reproduce the broadband spectrum of the PWN from radio to gamma-ray wavelengths. The analysis and modeling presented in this work have important implications for our general understanding of the structure and evolution of composite SNRs.

  8. HIV and AIDS

    MedlinePlus

    ... I Help a Friend Who Cuts? HIV and AIDS KidsHealth > For Teens > HIV and AIDS Print A A A Text Size What's in ... in human history. HIV causes a condition called acquired immunodeficiency syndrome — better known as AIDS . HIV destroys a type ...

  9. Designing State Aid Formulas

    ERIC Educational Resources Information Center

    Zhao, Bo; Bradbury, Katharine

    2009-01-01

    This paper designs a new equalization-aid formula based on fiscal gaps of local communities. When states are in transition to a new local aid formula, the issue of whether and how to hold existing aid harmless poses a challenge. The authors show that some previous studies and the formulas derived from them give differential weights to existing and…

  10. AIDS Education Curriculum Guide.

    ERIC Educational Resources Information Center

    Horry County Board of Education, Conway, SC.

    This curriculum guide was developed, based on sound principles of human growth and development, to present the most recently available information on AIDS (Acquired Immune Deficiency Syndrome). The curriculum presents information on the known facts about AIDS and the AIDS virus infection. It also addresses the potential for adolescents and adults…

  11. First Aid: Rashes

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy First Aid: Rashes KidsHealth > For Parents > First Aid: Rashes Print A A A Text Size Rashes ... For Kids For Parents MORE ON THIS TOPIC First Aid: Skin Infections Poison Ivy Erythema Multiforme Hives (Urticaria) ...

  12. First Aid: Burns

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy First Aid: Burns KidsHealth > For Parents > First Aid: Burns Print A A A Text Size Scald ... THIS TOPIC Kitchen: Household Safety Checklist Fireworks Safety First Aid: Sunburn Firesetting Fire Safety Burns Household Safety: Preventing ...

  13. First Aid: Croup

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy First Aid: Croup KidsHealth > For Parents > First Aid: Croup Print A A A Text Size Croup ... For Kids For Parents MORE ON THIS TOPIC First Aid: Coughing X-Ray Exam: Neck Why Is Hand ...

  14. First Aid: Falls

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy First Aid: Falls KidsHealth > For Parents > First Aid: Falls Print A A A Text Size en ... Floors, Doors & Windows, Furniture, Stairways: Household Safety Checklist First Aid: Broken Bones Head Injuries Preventing Children's Sports Injuries ...

  15. First Aid: Choking

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy First Aid: Choking KidsHealth > For Parents > First Aid: Choking Print A A A Text Size Choking ... usually are taught as part of any basic first-aid course. Reviewed by: Steven Dowshen, MD Date reviewed: ...

  16. First Aid: Dehydration

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy First Aid: Dehydration KidsHealth > For Parents > First Aid: Dehydration Print A A A Text Size Dehydration ... MORE ON THIS TOPIC Summer Safety Heat Illness First Aid: Heat Illness Sun Safety Dehydration Diarrhea Vomiting Word! ...

  17. First Aid: Animal Bites

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy First Aid: Animal Bites KidsHealth > For Parents > First Aid: Animal Bites Print A A A Text Size ... For Kids For Parents MORE ON THIS TOPIC First Aid & Safety Center Infections That Pets Carry Dealing With ...

  18. A Teaching Aids Exhibition.

    ERIC Educational Resources Information Center

    Mahanja, Salah

    1985-01-01

    Describes an exhibition for the benefit of teachers of English in Arab Primary Schools, which was prepared by third-year students at the Teachers College for Arab Teachers. The exhibition included games, songs, audiovisual aids, crossword puzzles, vocabulary, spelling booklets, preposition aids, and worksheet and lesson planning aids. (SED)

  19. Random output and hospital performance.

    PubMed

    Barros, Pedro Pita

    2003-11-01

    Many countries are under pressure to reform health care financing and delivery. Hospital care is one part of the health system that is under scrutiny. Private management initiatives are a possible way to increase efficiency in health care delivery. This motivates the interest in developing methodologies to assess hospital performance, recognizing hospitals as a different sort of firm. We present a simple way to describe hospital production: hospital output as a change in the distribution of survival probabilities. This output definition allows us to separate hospital production from patients' characteristics. The notion of "better performance" has a precise meaning: (first-order) stochastic dominance of a distribution of survival probabilities over another distribution. As an illustration, we compare, for an important DRG, private and public management and find that private management performs better, mainly in the range of high-survival probabilities. The measured performance difference cannot be attributed to input prices or to economies of scale and/or scope. It reflects pure technological and organisational differences.

  20. A communication aid for the physically handicapped.

    PubMed

    Jardine, P; Jerman, S; Seddon, N; Rees, J A

    1984-07-01

    A communications aid for the severely handicapped is described. The aid is primarily intended to be mounted on an electric wheelchair and to be powered from the chair's battery. It may be operated by any two-switch input system or by more elaborate controls such as joy-sticks. The central unit of the aid is a purpose-built 8085 microcomputer, the operating program and data tables being sorted in a 2 kbyte EPROM. The input control is used to drive a cursor around an 8 X 8 letter board array, the selected alphanumeric character being output to a liquid crystal display. Up to 64 messages, each of no more than 15 characters, can be composed and stored by the user and recalled as required. The messages are stored in a 2 kbyte CMOS memory and are retained when the aid is switched off. It is a simple matter to increase the number of stored messages. The aid was designed with the needs of a particular 15 year old, athetoid child in mind and the results of his tests of the aid will be briefly discussed.

  1. Space Derived Health Aids (AID, Heart Monitor)

    NASA Technical Reports Server (NTRS)

    1981-01-01

    CPI's spinoff from miniaturized pace circuitry is the new heart-assist device, the AID implantable automatic pulse generator. AID pulse generator monitors the heart continuously, recognizes onset of fibrillation, then administers a corrective electrical shock. A mini- computer, a power source, and two electrodes which sense heart activity are included in the unit. An associated system was also developed. It includes an external recorder to be worn by AID patients and a physician's console to display the data stored by the recorder. System provides a record of fibrillation occurrences and the ensuing defibrillation.

  2. Overload protection circuit for output driver

    DOEpatents

    Stewart, Roger G.

    1982-05-11

    A protection circuit for preventing excessive power dissipation in an output transistor whose conduction path is connected between a power terminal and an output terminal. The protection circuit includes means for sensing the application of a turn on signal to the output transistor and the voltage at the output terminal. When the turn on signal is maintained for a period of time greater than a given period without the voltage at the output terminal reaching a predetermined value, the protection circuit decreases the turn on signal to, and the current conduction through, the output transistor.

  3. Benefit From Directional Microphone Hearing Aids: Objective and Subjective Evaluations

    PubMed Central

    Park, Hee-Sung; Jin, Sun Hwa; Choi, Ji Eun; Cho, Yang-Sun; Hong, Sung Hwa

    2015-01-01

    Objectives The aims of this study were to find and compare the effect of directional (DIR) processing of two different hearing aids via both subjective and objective methods, to determine the association between the results of the subjective and objective evaluations, and to find out individual predictive factors influencing the DIR benefit. Methods Twenty-six hearing aid users fitted unilaterally with each two different experimental hearing aid performed modified Korean Hearing in Noise Test (K-HINT) in three DIR conditions; omnidirectional (OMNI) mode, OMNI plus noise reduction feature, fixed DIR mode. In order to determine benefits from DIR benefit within a hearing aid and compare performance of the DIR processing between hearing aids, a subjective questionnaire was administrated on speech quality (SQ) and discomfort in noise (DN) domain. Correlation analysis of factors influencing DIR benefit was accomplished. Results Benefits from switching OMNI mode to DIR mode within both hearing aids in K-HINT were about 2.8 (standard deviation, 3.5) and 2.1 dB SNR (signal to ratio; SD, 2.5), but significant difference in K-HINT results between OMNI and OMNI plus noise reduction algorithm was not shown. The subjective evaluation resulted in the better SQ and DN scores in DIR mode than those in OMNI mode. However, the difference of scores on both SQ and DN between the two hearing aids with DIR mode was not statistically significant. Any individual factors did not significantly affect subjective and objective DIR benefits. Conclusion DIR benefit was found not only in the objective measurement performed in the laboratory but also in the subjective questionnaires, but the subjective results was failed to have significant correlation with the DIR benefit obtained in the K-HINT. Factors influencing individual variation in perceptual DIR benefit were still hard to explain. PMID:26330918

  4. Hearing Aid Assembly

    NASA Technical Reports Server (NTRS)

    Grugel, Richard N. (Inventor)

    2002-01-01

    Progress in hearing aids has come a long way. Yet despite such progress hearing aids are not the perfect answer to many hearing problems. Some adult ears cannot accommodate tightly fitting hearing aids. Mouth movements such as chewing, talking, and athletic or other active endeavors also lead to loosely fitting ear molds. It is well accepted that loosely fitting hearing aids are the cause of feedback noise. Since feedback noise is the most common complaint of hearing aid wearers it has been the subject of various patents. Herein a hearing aid assembly is provided eliminating feedback noise. The assembly includes the combination of a hearing aid with a headset developed to constrict feedback noise.

  5. HIV, AIDS, and the Future

    MedlinePlus

    ... Navigation Bar Home Current Issue Past Issues HIV / AIDS HIV, AIDS, and the Future Past Issues / Summer 2009 Table ... and your loved ones from HIV/AIDS. The AIDS Memorial Quilt In 1987, a total of 1, ...

  6. Discovery of TeV Gamma-Ray Emission toward Supernova Remnant SNR G78.2+2.1

    NASA Astrophysics Data System (ADS)

    Aliu, E.; Archambault, S.; Arlen, T.; Aune, T.; Beilicke, M.; Benbow, W.; Bird, R.; Bouvier, A.; Bradbury, S. M.; Buckley, J. H.; Bugaev, V.; Byrum, K.; Cannon, A.; Cesarini, A.; Ciupik, L.; Collins-Hughes, E.; Connolly, M. P.; Cui, W.; Dickherber, R.; Duke, C.; Dumm, J.; Dwarkadas, V. V.; Errando, M.; Falcone, A.; Federici, S.; Feng, Q.; Finley, J. P.; Finnegan, G.; Fortson, L.; Furniss, A.; Galante, N.; Gall, D.; Gillanders, G. H.; Godambe, S.; Gotthelf, E. V.; Griffin, S.; Grube, J.; Gyuk, G.; Hanna, D.; Holder, J.; Huan, H.; Hughes, G.; Humensky, T. B.; Kaaret, P.; Karlsson, N.; Kertzman, M.; Khassen, Y.; Kieda, D.; Krawczynski, H.; Krennrich, F.; Lang, M. J.; Lee, K.; Madhavan, A. S.; Maier, G.; Majumdar, P.; McArthur, S.; McCann, A.; Millis, J.; Moriarty, P.; Mukherjee, R.; Nelson, T.; O'Faoláin de Bhróithe, A.; Ong, R. A.; Orr, M.; Otte, A. N.; Pandel, D.; Park, N.; Perkins, J. S.; Pohl, M.; Popkow, A.; Prokoph, H.; Quinn, J.; Ragan, K.; Reyes, L. C.; Reynolds, P. T.; Roache, E.; Rose, H. J.; Ruppel, J.; Saxon, D. B.; Schroedter, M.; Sembroski, G. H.; Şentürk, G. D.; Skole, C.; Telezhinsky, I.; Tešić, G.; Theiling, M.; Thibadeau, S.; Tsurusaki, K.; Tyler, J.; Varlotta, A.; Vassiliev, V. V.; Vincent, S.; Wakely, S. P.; Ward, J. E.; Weekes, T. C.; Weinstein, A.; Weisgarber, T.; Welsing, R.; Williams, D. A.; Zitzer, B.

    2013-06-01

    We report the discovery of an unidentified, extended source of very-high-energy gamma-ray emission, VER J2019+407, within the radio shell of the supernova remnant SNR G78.2+2.1, using 21.4 hr of data taken by the VERITAS gamma-ray observatory in 2009. These data confirm the preliminary indications of gamma-ray emission previously seen in a two-year (2007-2009) blind survey of the Cygnus region by VERITAS. VER J2019+407, which is detected at a post-trials significance of 7.5 standard deviations in the 2009 data, is localized to the northwestern rim of the remnant in a region of enhanced radio and X-ray emission. It has an intrinsic extent of 0{.\\!\\!^\\circ }23 +/- {0{.\\!\\!^\\circ }03_stat} {}^{+0{.\\!\\!^\\circ }04}_{-0{.\\!\\!^\\circ }02sys} and its spectrum is well-characterized by a differential power law (dN/dE = N 0 × (E/TeV)-Γ) with a photon index of Γ = 2.37 ± 0.14stat ± 0.20sys and a flux normalization of N 0 = 1.5 ± 0.2stat ± 0.4sys × 10-12 photon TeV-1 cm-2 s-1. This yields an integral flux of 5.2 ± 0.8stat ± 1.4sys × 10-12 photon cm-2 s-1 above 320 GeV, corresponding to 3.7% of the Crab Nebula flux. We consider the relationship of the TeV gamma-ray emission with the GeV gamma-ray emission seen from SNR G78.2+2.1 as well as that seen from a nearby cocoon of freshly accelerated cosmic rays. Multiple scenarios are considered as possible origins for the TeV gamma-ray emission, including hadronic particle acceleration at the SNR shock.

  7. Detailed study of SNR G306.3-0.9 using XMM-Newton and Chandra observations

    NASA Astrophysics Data System (ADS)

    Combi, J. A.; García, F.; Suárez, A. E.; Luque-Escamilla, P. L.; Paron, S.; Miceli, M.

    2016-08-01

    Aims: We aim to study the spatial distribution of the physical and chemical properties of the X-ray emitting plasma of the supernova remnant (SNR) G306.3-0.9 in detail to obtain constraints on its ionization stage, the progenitor supernova explosion, and the age of the remnant. Methods: We used combined data from XMM-Newton and Chandra observatories to study the X-ray morphology of G306.3-0.9 in detail. A spatially resolved spectral analysis was used to obtain physical and geometrical parameters of different regions of the remnant. Spitzer infrared observations, available in the archive, were also used to constrain the progenitor supernova and study the environment in which the remnant evolved. Results: The X-ray morphology of the remnant displays a non-uniform structure of semi-circular appearance, with a bright southwest region and very weak or almost negligible X-ray emission in its northern part. These results indicate that the remnant is propagating in a non-uniform environment as the shock fronts are encountering a high-density medium, where enhanced infrared emission is detected. The X-ray spectral analysis of the selected regions shows distinct emission-line features of several metal elements, confirming the thermal origin of the emission. The X-ray spectra are well represented by a combination of two absorbed thermal plasma models: one in equilibrium ionization (VAPEC) with a mean temperature of ~0.19 keV, and another out of equilibrium ionization (VNEI) at a higher temperature of ~1.1 or 1.6-1.9 keV. For regions located in the northeast, central, and southwest part of the SNR, we found elevated abundances of Si, S, Ar, Ca, and Fe, typical of ejecta material. The outer regions located northwest and south show values of the abundances above solar but lower than to those found in the central regions. This suggests that the composition of the emitting outer parts of the SNR is a combination of ejecta and shocked material of the interstellar medium. The

  8. DISCOVERY OF TeV GAMMA-RAY EMISSION TOWARD SUPERNOVA REMNANT SNR G78.2+2.1

    SciTech Connect

    Aliu, E.; Archambault, S.; Arlen, T.; Aune, T.; Beilicke, M.; Buckley, J. H.; Bugaev, V.; Dickherber, R.; Benbow, W.; Bird, R.; Cannon, A.; Collins-Hughes, E.; Bouvier, A.; Bradbury, S. M.; Byrum, K.; Cesarini, A.; Connolly, M. P.; Ciupik, L.; Cui, W.; Duke, C.; and others

    2013-06-20

    We report the discovery of an unidentified, extended source of very-high-energy gamma-ray emission, VER J2019+407, within the radio shell of the supernova remnant SNR G78.2+2.1, using 21.4 hr of data taken by the VERITAS gamma-ray observatory in 2009. These data confirm the preliminary indications of gamma-ray emission previously seen in a two-year (2007-2009) blind survey of the Cygnus region by VERITAS. VER J2019+407, which is detected at a post-trials significance of 7.5 standard deviations in the 2009 data, is localized to the northwestern rim of the remnant in a region of enhanced radio and X-ray emission. It has an intrinsic extent of 0.23 Degree-Sign .23 {+-} 0. Degree-Sign 03{sub stat-0 Degree-Sign .02sys}{sup +0 Degree-Sign .04} and its spectrum is well-characterized by a differential power law (dN/dE = N{sub 0} Multiplication-Sign (E/TeV){sup -{Gamma}}) with a photon index of {Gamma} = 2.37 {+-} 0.14{sub stat} {+-} 0.20{sub sys} and a flux normalization of N{sub 0} = 1.5 {+-} 0.2{sub stat} {+-} 0.4{sub sys} Multiplication-Sign 10{sup -12} photon TeV{sup -1} cm{sup -2} s{sup -1}. This yields an integral flux of 5.2 {+-} 0.8{sub stat} {+-} 1.4{sub sys} Multiplication-Sign 10{sup -12} photon cm{sup -2} s{sup -1} above 320 GeV, corresponding to 3.7% of the Crab Nebula flux. We consider the relationship of the TeV gamma-ray emission with the GeV gamma-ray emission seen from SNR G78.2+2.1 as well as that seen from a nearby cocoon of freshly accelerated cosmic rays. Multiple scenarios are considered as possible origins for the TeV gamma-ray emission, including hadronic particle acceleration at the SNR shock.

  9. Toward implementation of a flexible hearing aid measurement system.

    PubMed

    Cudahy, E; Link, H C

    1991-06-01

    An evaluation of a computerized hearing aid measurement system was performed with input and output compression hearing aids stimulated using high-quality audio equipment. The results of the computer measurements were compared to those from a manual technique using conventional laboratory instrumentation. The results from the computerized and manual methods matched very closely. However, the computer system was found to be considerably more flexible than conventional instrumentation and was much easier to use. PMID:1939724

  10. Tool reconstructs data input points corresponding to first order output graph

    NASA Technical Reports Server (NTRS)

    Biggs, R. E.

    1968-01-01

    Tool aids in graphic determination of input values for any first order lag system of known gain and time constant where the corresponding output function is displayed graphically and can be described by a first order differential equation. This tool permits a rapid reconstruction of input points.

  11. Combining and connecting linear, multi-input, multi-output subsystem models

    NASA Technical Reports Server (NTRS)

    Duke, E. L.

    1986-01-01

    The mathematical background for combining and connecting linear, multi-input, multi-output subsystem models into an overall system model is provided. Several examples of subsystem configurations are examined in detail. A description of a MATRIX (sub x) command file to aid in the process of combining and connecting these subsystem models is contained.

  12. Mathematics and the Heart: Understanding Cardiac Output

    ERIC Educational Resources Information Center

    Champanerkar, Jyoti

    2013-01-01

    This paper illustrates a biological application of the concepts of relative change and area under a curve, from mathematics. We study two biological measures "relative change in cardiac output" and "cardiac output", which are predictors of heart blockages and other related ailments. Cardiac output refers to the quantity of…

  13. Detailed 21 cm observations towards the TeV γ-ray SNR HESS J1731-347

    NASA Astrophysics Data System (ADS)

    Fukuda, Tatsuya; Yamamoto, Hiroaki; Fukui, Yasuo; Torii, Kazufumi; Hayakawa, Takahiro; Okuda, Takeshi; Sano, Hidetoshi; Yoshiike, Satoshi

    2012-10-01

    HESS J1731-347 is one of the unique SNRs which show the TeV gamma-ray shell like morphology. Our new study succeeded to reveal the distributions of the ISM proton that coincide well with the TeV gamma-ray distributions and discussed that both the hadronic and leptonic processes are possibly working in this region. However, the present ISM resolutions of a few arcmin of the given data sets are not sufficient to understand the detailed ISM distributions and the origin of the gamma-ray emission. We will use the ATCA to image 21cm radio continuum emission and HI emission in the region to a resolution of ~30" and study the interaction between the shock wave and the ISM in detail. Such results are a crucial component in testing for the origin of SNR gamma-rays.

  14. The x ray population in globular clusters and three crab-like SNR in the large Magellanic cloud

    NASA Technical Reports Server (NTRS)

    Helfand, David J.

    1993-01-01

    This document is to serve as the requisite Final Technical Report on grant NAG5-1557 which was awarded under the NASA ROSAT Guest Investigator Program to Columbia University. In response to the NASA Research Anouncement describing the first round of Guest Investigations to be carried out under the U.S.-German ROSAT Program (AO-1), the PI submitted several proposals, three of which were accepted in part: (1) the x-ray population of globular clusters; (2) three crab-like SNR in the Large Magellanic Cloud; and (3) x rays from nearby radio pulsars. The status of these three programs as of 31 May 1993, the termination date of the grant, is reported.

  15. Electrical vestibular stimuli to enhance vestibulo-motor output and improve subject comfort.

    PubMed

    Forbes, Patrick A; Dakin, Christopher J; Geers, Anoek M; Vlaar, Martijn P; Happee, Riender; Siegmund, Gunter P; Schouten, Alfred C; Blouin, Jean-Sébastien

    2014-01-01

    Electrical vestibular stimulation is often used to assess vestibulo-motor and postural responses in both clinical and research settings. Stochastic vestibular stimulation (SVS) is a recently established technique with many advantages over its square-wave counterpart; however, the evoked muscle responses remain relatively small. Although the vestibular-evoked responses can be enhanced by increasing the stimulus amplitude, subjects often perceive these higher intensity electrical stimuli as noxious or painful. Here, we developed multisine vestibular stimulation (MVS) signals that include precise frequency contributions to increase signal-to-noise ratios (SNR) of stimulus-evoked muscle and motor responses. Subjects were exposed to three different MVS stimuli to establish that: 1) MVS signals evoke equivalent vestibulo-motor responses compared to SVS while improving subject comfort and reducing experimentation time, 2) stimulus-evoked vestibulo-motor responses are reliably estimated as a linear system and 3) specific components of the cumulant density time domain vestibulo-motor responses can be targeted by controlling the frequency content of the input stimulus. Our results revealed that in comparison to SVS, MVS signals increased the SNR 3-6 times, reduced the minimum experimentation time by 85% and improved subjective measures of comfort by 20-80%. Vestibulo-motor responses measured using both EMG and force were not substantially affected by nonlinear distortions. In addition, by limiting the contribution of high frequencies within the MVS input stimulus, the magnitude of the medium latency time domain motor output response was increased by 58%. These results demonstrate that MVS stimuli can be designed to target and enhance vestibulo-motor output responses while simultaneously improving subject comfort, which should prove beneficial for both research and clinical applications. PMID:24392130

  16. Electrical vestibular stimuli to enhance vestibulo-motor output and improve subject comfort.

    PubMed

    Forbes, Patrick A; Dakin, Christopher J; Geers, Anoek M; Vlaar, Martijn P; Happee, Riender; Siegmund, Gunter P; Schouten, Alfred C; Blouin, Jean-Sébastien

    2014-01-01

    Electrical vestibular stimulation is often used to assess vestibulo-motor and postural responses in both clinical and research settings. Stochastic vestibular stimulation (SVS) is a recently established technique with many advantages over its square-wave counterpart; however, the evoked muscle responses remain relatively small. Although the vestibular-evoked responses can be enhanced by increasing the stimulus amplitude, subjects often perceive these higher intensity electrical stimuli as noxious or painful. Here, we developed multisine vestibular stimulation (MVS) signals that include precise frequency contributions to increase signal-to-noise ratios (SNR) of stimulus-evoked muscle and motor responses. Subjects were exposed to three different MVS stimuli to establish that: 1) MVS signals evoke equivalent vestibulo-motor responses compared to SVS while improving subject comfort and reducing experimentation time, 2) stimulus-evoked vestibulo-motor responses are reliably estimated as a linear system and 3) specific components of the cumulant density time domain vestibulo-motor responses can be targeted by controlling the frequency content of the input stimulus. Our results revealed that in comparison to SVS, MVS signals increased the SNR 3-6 times, reduced the minimum experimentation time by 85% and improved subjective measures of comfort by 20-80%. Vestibulo-motor responses measured using both EMG and force were not substantially affected by nonlinear distortions. In addition, by limiting the contribution of high frequencies within the MVS input stimulus, the magnitude of the medium latency time domain motor output response was increased by 58%. These results demonstrate that MVS stimuli can be designed to target and enhance vestibulo-motor output responses while simultaneously improving subject comfort, which should prove beneficial for both research and clinical applications.

  17. Detailed investigation of the gamma-ray emission in the vicinity of SNR W28 with Fermi-LAT

    SciTech Connect

    Hanabata, Y.; Katagiri, H.; Hewitt, J.W.; Ballet, J.; Fukui, Y.; Hayakawa, T.; Lemoine-Goumard, M.; Strong, A. W.; Yamazaki, R. E-mail: katagiri@mx.ibaraki.ac.jp

    2014-05-10

    We present a detailed investigation of the γ-ray emission in the vicinity of the supernova remnant (SNR) W28 (G6.4–0.1) observed by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. We detected significant γ-ray emission spatially coincident with TeV sources HESS J1800–240A, B, and C, located outside the radio boundary of the SNR. Their spectra in the 2-100 GeV band are consistent with the extrapolation of the power-law spectra of the TeV sources. We also identified a new source of GeV emission, dubbed Source W, which lies outside the boundary of TeV sources and coincides with radio emission from the western part of W28. All of the GeV γ-ray sources overlap with molecular clouds in the velocity range from 0 to 20 km s{sup –1}. Under the assumption that the γ-ray emission toward HESS J1800–240A, B, and C comes from π{sup 0} decay due to the interaction between the molecular clouds and cosmic rays (CRs) escaping from W28, they can be naturally explained by a single model in which the CR diffusion coefficient is smaller than the theoretical expectation in the interstellar space. The total energy of the CRs escaping from W28 is constrained through the same modeling to be larger than ∼2 × 10{sup 49} erg. The emission from Source W can also be explained with the same CR escape scenario.

  18. Detailed Investigation of the Gamma-Ray Emission in the Vicinity of SNR W28 with FERMI-LAT

    NASA Technical Reports Server (NTRS)

    Hanabata, Y.; Katagiri, H.; Hewitt, John William; Ballet, J.; Fukazawa, Y.; Fukui, Y.; Hayakawa, T.; Lemoine-Goumard, M.; Pedaletti, G.; Strong, A. W.; Torres, D. F.; Yamazaki, R.

    2014-01-01

    We present a detailed investigation of the Gamma-ray emission in the vicinity of the supernova remnant (SNR) W28 (G6.4-0.1) observed by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. We detected significant ? -ray emission spatially coincident with TeV sources HESS J1800-240A, B, and C, located outside the radio boundary of the SNR. Their spectra in the 2-100 GeV band are consistent with the extrapolation of the power-law spectra of the TeV sources. We also identified a new source of GeV emission, dubbed Source W, which lies outside the boundary of TeV sources and coincides with radio emission from the western part of W28. All of the GeV Gamma-ray sources overlap with molecular clouds in the velocity range from 0 to 20 km s (exp-1). Under the assumption that the Gamma-ray emission toward HESS J1800-240A, B, and C comes from 3.14(exp0) decay due to the interaction between the molecular clouds and cosmic rays (CRs) escaping from W28, they can be naturally explained by a single model in which the CR diffusion coefficient is smaller than the theoretical expectation in the interstellar space. The total energy of the CRs escaping from W28 is constrained through the same modeling to be larger than is approximately 2 × 10(exp49) erg. The emission from Source W can also be explained with the same CR escape scenario.

  19. Detailed Investigation of the Gamma-Ray Emission in the Vicinity of SNR W28 with FERMI-LAT

    NASA Astrophysics Data System (ADS)

    Hanabata, Y.; Katagiri, H.; Hewitt, J. W.; Ballet, J.; Fukazawa, Y.; Fukui, Y.; Hayakawa, T.; Lemoine-Goumard, M.; Pedaletti, G.; Strong, A. W.; Torres, D. F.; Yamazaki, R.

    2014-05-01

    We present a detailed investigation of the γ-ray emission in the vicinity of the supernova remnant (SNR) W28 (G6.4-0.1) observed by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. We detected significant γ-ray emission spatially coincident with TeV sources HESS J1800-240A, B, and C, located outside the radio boundary of the SNR. Their spectra in the 2-100 GeV band are consistent with the extrapolation of the power-law spectra of the TeV sources. We also identified a new source of GeV emission, dubbed Source W, which lies outside the boundary of TeV sources and coincides with radio emission from the western part of W28. All of the GeV γ-ray sources overlap with molecular clouds in the velocity range from 0 to 20 km s-1. Under the assumption that the γ-ray emission toward HESS J1800-240A, B, and C comes from π0 decay due to the interaction between the molecular clouds and cosmic rays (CRs) escaping from W28, they can be naturally explained by a single model in which the CR diffusion coefficient is smaller than the theoretical expectation in the interstellar space. The total energy of the CRs escaping from W28 is constrained through the same modeling to be larger than ~2 × 1049 erg. The emission from Source W can also be explained with the same CR escape scenario.

  20. OT2_pghavami_1: Herschel imaging of SNR G292.0+1.8: Cas A's older cousin?

    NASA Astrophysics Data System (ADS)

    Ghavamian, P.

    2011-09-01

    It is well-known that supernovae play a key role in creating and distributing elements throughout the universe, but less well-known is their contribution to the overall budget of dust in the ISM. Theoretical models suggest that core-collapse supernovae should produce large quantities of dust, but observational evidence for this is still debated. Even if significant quantities of dust are produced, does it survive the passage of the reverse shock to enter the ISM? Does the forward shock destroy all dust that it encounters? Near and mid-IR observations with Spitzer and AKARI have begun to answer these questions, but the long wavelength cameras of Herschel are necessary for a complete picture. We propose detailed observations of G292.0+1.8, a large Galactic supernova remnant (SNR) that has been called the "older cousin" of Cassiopeia A. One of the few known oxygen-rich remnants, G292 is a 3000 year old textbook example of a core-collapse SNR expanding into its own circumstellar medium (CSM), the wind of a red giant. It is one of the most well-studied SNRs at all wavelengths, from radio to X-rays. At 8' in diameter, it is large enough for the emission from the forward-shock CSM to be well-separated from that of the reverse-shocked ejecta, yet it is still small enough to be fully covered by Herschel in a reasonably small amount of time. We will obtain PACS and SPIRE imaging of the entire remnant. PACS observations will be sensitive to forward-shocked material, while SPIRE data will tell us whether large amounts of ejecta dust are present in the remnant. We will use the far-IR data in conjunction with X-ray and optical data to obtain a complete picture of the dynamical evolution of the remnant, and advance our understanding of the nature of dust in the universe.

  1. X-RAY EMISSION FROM HESS J1731-347/SNR G353.6-0.7 AND CENTRAL COMPACT SOURCE XMMS J173203-344518

    SciTech Connect

    Tian, W. W.; Li, Z.; Leahy, D. A.; Yang, J.; Lu, D.; Yang, X. J.; Yamazaki, R. E-mail: wtian@ucalgary.c

    2010-04-01

    We present new results of the HESS J1731-347/SNR G353.6-0.7 system from XMM-Newton and Suzaku X-ray observations and Delinha CO observations. We discover extended hard X-rays coincident with the bright, extended TeV source HESS J1731-347 and the shell of the radio supernova remnant (SNR). We find that spatially resolved X-ray spectra can generally be characterized by an absorbed power-law model, with a photon index of {approx}2, typical of non-thermal emission. A bright X-ray compact source, XMMS J173203-344518, is also detected near the center of the SNR. We find no evidence of a radio counterpart or an extended X-ray morphology for this source, making it unlikely to be a pulsar wind nebular (PWN). The spectrum of the source can be well fitted by an absorbed blackbody with a temperature of {approx}0.5 keV plus a power-law tail with a photon index of {approx}5, reminiscent of the X-ray emission of a magnetar. CO observations toward the inner part of the High Energy Stereoscopic System (HESS) source reveal a bright cloud component at -20 +- 4 km s{sup -1}, which is likely located at the same distance of {approx}3.2 kpc as the SNR. Based on the probable association between the X-ray and gamma-ray emissions and likely association between the CO cloud and the SNR, we argue that the extended TeV emission originates from the interaction between the SNR shock and the adjacent CO clouds rather than from a PWN.

  2. THE NEUTRAL INTERSTELLAR GAS TOWARD SNR W44: CANDIDATES FOR TARGET PROTONS IN HADRONIC {gamma}-RAY PRODUCTION IN A MIDDLE-AGED SUPERNOVA REMNANT

    SciTech Connect

    Yoshiike, S.; Fukuda, T.; Sano, H.; Ohama, A.; Moribe, N.; Torii, K.; Hayakawa, T.; Okuda, T.; Yamamoto, H.; Mizuno, N.; Onishi, T.; Fukui, Y.; Tajima, H.; Maezawa, H.; Mizuno, A.; Nishimura, A.; Kimura, K.; Ogawa, H.; Giuliani, A.; Koo, B.-C.

    2013-05-10

    We present an analysis of the interstellar medium (ISM) toward the {gamma}-ray supernova remnant (SNR) W44. We used NANTEN2 {sup 12}CO(J = 2-1) and {sup 12}CO(J = 1-0) data and Arecibo H I data in order to identify the molecular and atomic gas in the SNR. We confirmed that the molecular gas is located in the SNR shell with a primary peak toward the eastern edge of the shell. We newly identified high-excitation molecular gas along the eastern shell of the SNR in addition to the high-excitation broad gas previously observed inside the shell; the line intensity ratio between the {sup 12}CO(J = 2-1) and {sup 12}CO(J = 1-0) transitions in these regions is greater than {approx}1.0, suggesting a kinetic temperature of 30 K or higher, which is most likely due to heating by shock interaction. By comparing the ISM with {gamma}-rays, we find that target protons of hadronic origin are dominated by molecular protons of average density around 200 cm{sup -3}, where the possible contribution of atomic protons is 10% or less. This average density is consistent with the recent discovery of the low-energy {gamma}-rays suppressed in 50 MeV-10 GeV as observed with AGILE and Fermi. The {gamma}-ray spectrum differs from place to place in the SNR, suggesting that the cosmic-ray (CR) proton spectrum significantly changes within the middle-aged SNR perhaps due to the energy-dependent escape of CR protons from the acceleration site. We finally derive a total CR proton energy of {approx}10{sup 49} erg, consistent with the SN origin of the majority of the CRs in the Galaxy.

  3. X-Ray Emission from HESS J1731-347/SNR G353.6-0.7 and Central Compact Source XMMS J173203-344518

    NASA Astrophysics Data System (ADS)

    Tian, W. W.; Li, Z.; Leahy, D. A.; Yang, J.; Yang, X. J.; Yamazaki, R.; Lu, D.

    2010-04-01

    We present new results of the HESS J1731-347/SNR G353.6-0.7 system from XMM-Newton and Suzaku X-ray observations and Delinha CO observations. We discover extended hard X-rays coincident with the bright, extended TeV source HESS J1731-347 and the shell of the radio supernova remnant (SNR). We find that spatially resolved X-ray spectra can generally be characterized by an absorbed power-law model, with a photon index of ~2, typical of non-thermal emission. A bright X-ray compact source, XMMS J173203-344518, is also detected near the center of the SNR. We find no evidence of a radio counterpart or an extended X-ray morphology for this source, making it unlikely to be a pulsar wind nebular (PWN). The spectrum of the source can be well fitted by an absorbed blackbody with a temperature of ~0.5 keV plus a power-law tail with a photon index of ~5, reminiscent of the X-ray emission of a magnetar. CO observations toward the inner part of the High Energy Stereoscopic System (HESS) source reveal a bright cloud component at -20 ± 4 km s-1, which is likely located at the same distance of ~3.2 kpc as the SNR. Based on the probable association between the X-ray and γ-ray emissions and likely association between the CO cloud and the SNR, we argue that the extended TeV emission originates from the interaction between the SNR shock and the adjacent CO clouds rather than from a PWN.

  4. Some aspects of the NASTRAN program output

    NASA Technical Reports Server (NTRS)

    Gregory, D. J.

    1972-01-01

    The NASTRAN program output is discussed from a structural analysts point of view, and the simple modifications which were made to the program in order to improve it are also described. The convenience of the output for use in original design work is critically appraised and compared with the output from ASTRAL. It is shown that considerable hand calculation is necessary in order to extract useful load distribution data from the available NASTRAN output. For this reason, some effort was directed toward providing additional force output for the NASTRAN shear panel element.

  5. Multi-frequency observations of SNR J0453-6829 in the LMC. A composite supernova remnant with a pulsar wind nebula

    NASA Astrophysics Data System (ADS)

    Haberl, F.; Filipović, M. D.; Bozzetto, L. M.; Crawford, E. J.; Points, S. D.; Pietsch, W.; De Horta, A. Y.; Tothill, N.; Payne, J. L.; Sasaki, M.

    2012-07-01

    Context. The Large Magellanic Cloud (LMC) is rich in supernova remnants (SNRs), which can be investigated in detail with radio, optical, and X-ray observations. SNR J0453-6829 is an X-ray and radio-bright remnant in the LMC, within which previous studies revealed the presence of a pulsar wind nebula (PWN), making it one of the most interesting SNRs in the Local Group of galaxies. Aims: We study the emission of SNR J0453-6829 to improve our understanding of its morphology, spectrum, and thus the emission mechanisms in the shell and the PWN of the remnant. Methods: We obtained new radio data with the Australia Telescope Compact Array and analysed archival XMM-Newton observations of SNR J0453-6829. We studied the morphology of SNR J0453-6829 from radio, optical, and X-ray images and investigated the energy spectra in the different parts of the remnant. Results: Our radio results confirm that this LMC SNR hosts a typical PWN. The prominent central core of the PWN exhibits a radio spectral index αCore of -0.04 ± 0.04, while in the rest of the SNR shell the spectral slope is somewhat steeper with αShell = -0.43 ± 0.01. We detect regions with a mean polarisation of P ≅ (12 ± 4)% at 6 cm and (9 ± 2)% at 3 cm. The full remnant is of roughly circular shape with dimensions of (31 ± 1) pc × (29 ± 1) pc. The spectral analysis of the XMM-Newton EPIC and RGS spectra allowed us to derive physical parameters for the SNR. Somewhat depending on the spectral model, we obtain for the remnant a shock temperature of around 0.2 keV and estimate the dynamical age to 12 000-15 000 years. Using a Sedov model we further derive an electron density in the X-ray emitting material of 1.56 cm-3, typical for LMC remnants, a large swept-up mass of 830 M⊙, and an explosion energy of 7.6 × 1050 erg. These parameters indicate a well evolved SNR with an X-ray spectrum dominated by emission from the swept-up material.

  6. Model output: fact or artefact?

    NASA Astrophysics Data System (ADS)

    Melsen, Lieke

    2015-04-01

    As a third-year PhD-student, I relatively recently entered the wonderful world of scientific Hydrology. A science that has many pillars that directly impact society, for example with the prediction of hydrological extremes (both floods and drought), climate change, applications in agriculture, nature conservation, drinking water supply, etcetera. Despite its demonstrable societal relevance, hydrology is often seen as a science between two stools. Like Klemeš (1986) stated: "By their academic background, hydrologists are foresters, geographers, electrical engineers, geologists, system analysts, physicists, mathematicians, botanists, and most often civil engineers." Sometimes it seems that the engineering genes are still present in current hydrological sciences, and this results in pragmatic rather than scientific approaches for some of the current problems and challenges we have in hydrology. Here, I refer to the uncertainty in hydrological modelling that is often neglected. For over thirty years, uncertainty in hydrological models has been extensively discussed and studied. But it is not difficult to find peer-reviewed articles in which it is implicitly assumed that model simulations represent the truth rather than a conceptualization of reality. For instance in trend studies, where data is extrapolated 100 years ahead. Of course one can use different forcing datasets to estimate the uncertainty of the input data, but how to prevent that the output is not a model artefact, caused by the model structure? Or how about impact studies, e.g. of a dam impacting river flow. Measurements are often available for the period after dam construction, so models are used to simulate river flow before dam construction. Both are compared in order to qualify the effect of the dam. But on what basis can we tell that the model tells us the truth? Model validation is common nowadays, but validation only (comparing observations with model output) is not sufficient to assume that a

  7. Model output: fact or artefact?

    NASA Astrophysics Data System (ADS)

    Melsen, Lieke

    2015-04-01

    As a third-year PhD-student, I relatively recently entered the wonderful world of scientific Hydrology. A science that has many pillars that directly impact society, for example with the prediction of hydrological extremes (both floods and drought), climate change, applications in agriculture, nature conservation, drinking water supply, etcetera. Despite its demonstrable societal relevance, hydrology is often seen as a science between two stools. Like Klemeš (1986) stated: "By their academic background, hydrologists are foresters, geographers, electrical engineers, geologists, system analysts, physicists, mathematicians, botanists, and most often civil engineers." Sometimes it seems that the engineering genes are still present in current hydrological sciences, and this results in pragmatic rather than scientific approaches for some of the current problems and challenges we have in hydrology. Here, I refer to the uncertainty in hydrological modelling that is often neglected. For over thirty years, uncertainty in hydrological models has been extensively discussed and studied. But it is not difficult to find peer-reviewed articles in which it is implicitly assumed that model simulations represent the truth rather than a conceptualization of reality. For instance in trend studies, where data is extrapolated 100 years ahead. Of course one can use different forcing datasets to estimate the uncertainty of the input data, but how to prevent that the output is not a model artefact, caused by the model structure? Or how about impact studies, e.g. of a dam impacting river flow. Measurements are often available for the period after dam construction, so models are used to simulate river flow before dam construction. Both are compared in order to qualify the effect of the dam. But on what basis can we tell that the model tells us the truth? Model validation is common nowadays, but validation only (comparing observations with model output) is not sufficient to assume that a

  8. AIDS in South Africa.

    PubMed

    Ijsselmuiden, C; Evian, C; Matjilla, J; Steinberg, M; Schneider, H

    1993-01-01

    The National AIDS Convention in South Africa (NACOSA) in October 1992 was the first real attempt to address HIV/AIDS. In Soweto, government, the African National Congress, nongovernmental organizations, and organized industry and labor representatives worked for 2 days to develop a national plan of action, but it did not result in a united effort to fight AIDS. The highest HIV infection rates in South Africa are among the KwaZulu in Natal, yet the Inkatha Freedom Party did not attend NACOSA. This episode exemplifies the key obstacles for South Africa to prevent and control AIDS. Inequality of access to health care may explain why health workers did not diagnose the first AIDS case in blacks until 1985. Migrant labor, Bantu education, and uprooted communities affect the epidemiology of HIV infection. Further, political and social polarization between blacks and whites contributes to a mindset that AIDS is limited to the other race which only diminishes the personal and collective sense of susceptibility and the volition and aptitude to act. The Department of National Health and Population Development's voluntary register of anonymously reported cases of AIDS specifies 1517 cumulative AIDS cases (October 1992), but this number is low. Seroprevalence studies show between 400,000-450,000 HIV positive cases. Public hospitals cannot give AIDS patients AZT and DDI. Few communities provided community-based care. Not all hospitals honor confidentiality and patients' need for autonomy. Even though HIV testing is not mandatory, it is required sometimes, e.g., HIV testing of immigrants. AIDS Training, Information and Counselling Centers are in urban areas, but not in poor areas where the need is most acute. The government just recently developed in AIDS education package for schools, but too many people consider it improper, so it is not being used. The poor quality education provided blacks would make it useless anyhow. Lifting of the academic boycott will allow South African

  9. Pediatric AIDS: psychosocial impact.

    PubMed

    Mangos, J A; Doran, T; Aranda-Naranjo, B; Rodriguez-Escobar, Y; Scott, A; Setzer, J R

    1990-06-01

    There is no question that the domain of the American family has been invaded by the HIV infection/AIDS epidemic. The disease, and particularly its form affecting children (pediatric AIDS), has had marked psychosocial impact on patients and families (intellectual/cognitive, emotional/behavioral, spiritual, and financial) and on our society in general (adverse or favorable). These impacts of pediatric AIDS are discussed in the present communication. PMID:2371699

  10. Optical Waveguide Output Couplers Fabricated in Polymers

    NASA Technical Reports Server (NTRS)

    Watson, Michael D.; Abushagur, Mustafa A. G.; Ashley, Paul R.; Johnson-Cole, Helen

    1998-01-01

    Waveguide output couplers fabricated in Norland Optical Adhesive (NOA) #81 and AMOCO Ultradel 9020D polyimide are investigated. The output couplers are implemented using periodic relief gratings on a planar waveguide. Design theory of the couplers is based on the perturbation approach. Coupling of light from waveguide propagation modes to output radiation modes is described by coupled mode theory and the transmission line approximation of the perturbed area (grating structure). Using these concepts, gratings can be accurately designed to output a minimum number of modes at desired output angles. Waveguide couplers were designed using these concepts. These couplers were fabricated and analyzed for structural accuracy, output beam accuracy, and output efficiency. The results for the two different materials are compared.

  11. HIV / AIDS Network.

    PubMed

    1995-01-01

    The HIV/AIDS Network and the Philippines Department of Health (DOH) collaborated to produce the AIDS Candlelight Memorial at the Philippine International Convention Center (PICC), May 1995, and World AIDS Day activities on December 1, 1995. After the memorial, a fashion show, "Body Shots," provided a channel for information on acquired immunodeficiency syndrome (AIDS). On World AIDS Day, at the request of DOH, the Network provided speakers who lectured on human immunodeficiency virus (HIV) and AIDS in different government offices. Prior to World AIDS Day, the Network focused on strengthening its cohesiveness and building the capabilities of its member organizations through lectures and symposia during November. Network activities were coordinated by the Remedios AIDS Foundation with support from the other members of the Coordinating Council: Health Action Information Network (HAIN); Caritas; Kabalikat, Stop Trafficking of Pilopinos Foundation, Inc. (STOP);and the Library Foundation (TLF). The Coordinating Council elected for 1996 includes the Remedios AIDS Foundation, HAIN, Caritas, TLF, STOP, the Foundation for Adolescent Development (FAD), and the Salvation Army. PMID:12291699

  12. AIDS and civil disobedience.

    PubMed

    Spiers, H R

    1989-01-01

    Members of groups such as ACT UP (AIDS Coalition to Unleash Power) risk arrest and criminal charges to protest laws and policies they view as unjust to persons with AIDS. Spiers, a founding member of ACT UP, discusses the rationale behind the tactics of civil disobedience employed by AIDS activists. He argues that civil disobedience is justified by American political and legal traditions, and by the federal government's lack of response to the needs of its citizens. Spiers warns that while AIDS protests have been nonviolent and characterized by conscientious planning and execution, violence cannot be ruled out as a "political act born of desperation."

  13. AIDS: Psychosocial Dimensions

    PubMed Central

    Stapleton, Dan

    1986-01-01

    In order to provide comprehensive care to patients who have AIDS, it is important for the family physician to understand the psychosocial elements of the disease. Homosexual men who have AIDS face particular problems, such as the disclosure of sexual orientation to family and friends. Issues discussed in this article include the reactions of the patient, family and friends to the diagnosis, the stigma of AIDS, the patient's support network, and preparations for disability and death. The facts about AIDS are discussed briefly, and the psychosocial implications of the illness for patients and their “significant others” are examined. The role of the family physician is highlighted. PMID:21267233

  14. PREVIMER : Meteorological inputs and outputs

    NASA Astrophysics Data System (ADS)

    Ravenel, H.; Lecornu, F.; Kerléguer, L.

    2009-09-01

    PREVIMER is a pre-operational system aiming to provide a wide range of users, from private individuals to professionals, with short-term forecasts about the coastal environment along the French coastlines bordering the English Channel, the Atlantic Ocean, and the Mediterranean Sea. Observation data and digital modelling tools first provide 48-hour (probably 96-hour by summer 2009) forecasts of sea states, currents, sea water levels and temperatures. The follow-up of an increasing number of biological parameters will, in time, complete this overview of coastal environment. Working in partnership with the French Naval Hydrographic and Oceanographic Service (Service Hydrographique et Océanographique de la Marine, SHOM), the French National Weather Service (Météo-France), the French public science and technology research institute (Institut de Recherche pour le Développement, IRD), the European Institute of Marine Studies (Institut Universitaire Européen de la Mer, IUEM) and many others, IFREMER (the French public institute fo marine research) is supplying the technologies needed to ensure this pertinent information, available daily on Internet at http://www.previmer.org, and stored at the Operational Coastal Oceanographic Data Centre. Since 2006, PREVIMER publishes the results of demonstrators assigned to limited geographic areas and to specific applications. This system remains experimental. The following topics are covered : Hydrodynamic circulation, sea states, follow-up of passive tracers, conservative or non-conservative (specifically of microbiological origin), biogeochemical state, primary production. Lastly, PREVIMER provides researchers and R&D departments with modelling tools and access to the database, in which the observation data and the modelling results are stored, to undertake environmental studies on new sites. The communication will focus on meteorological inputs to and outputs from PREVIMER. It will draw the lessons from almost 3 years during

  15. What is the potential for context aware communication aids?

    PubMed

    Judge, Simon; Hawley, Mark S; Cunningham, Stuart; Kirton, Andrea

    2014-01-01

    Use of voice output communication aids (VOCAs) can be a very effective strategy to assist people with speech impairments in communicating. Despite this, people who use communication aids often express frustration with VOCAs-desiring devices that are simpler, quicker and more effective to use. Whilst it is not possible to resolve all these issues with technology, it is argued that significant progress can be made. The use of contextual information is one development that could improve the simplicity and effectiveness of communication aid design. Improving the effectiveness of communication aids, including through the use of context support, is a goal of the NIHR Devices for Dignity Assistive Technology Theme. This discussion paper examines the potential for creating 'context aware' communication aids. Three projects in which the authors have been involved are described to illustrate different approaches to the use of contextual information. PMID:26418171

  16. AIDS is your business.

    PubMed

    Rosen, Sydney; Simon, Jonathon; Vincent, Jeffrey R; MacLeod, William; Fox, Matthew; Thea, Donald M

    2003-02-01

    If your company operates in a developing country, AIDS is your business. While Africa has received the most attention, AIDS is also spreading swiftly in other parts of the world. Russia and Ukraine had the fastest-growing epidemics last year, and many experts believe China and India will suffer the next tidal wave of infection. Why should executives be concerned about AIDS? Because it is destroying the twin rationales of globalization strategy-cheap labor and fast-growing markets--in countries where people are heavily affected by the epidemic. Fortunately, investments in programs that prevent infection and provide treatment for employees who have HIV/AIDS are profitable for many businesses--that is, they lead to savings that outweigh the programs' costs. Due to the long latency period between HIV infection and the onset of AIDS symptoms, a company is not likely to see any of the costs of HIV/AIDS until five to ten years after an employee is infected. But executives can calculate the present value of epidemic-related costs by using the discount rate to weigh each cost according to its expected timing. That allows companies to think about expenses on HIV/AIDS prevention and treatment programs as investments rather than merely as costs. The authors found that the annual cost of AIDS to six corporations in South Africa and Botswana ranged from 0.4% to 5.9% of the wage bill. All six companies would have earned positive returns on their investments if they had provided employees with free treatment for HIV/AIDS in the form of highly active antiretroviral therapy (HAART), according to the mathematical model the authors used. The annual reduction in the AIDS "tax" would have been as much as 40.4%. The authors' conclusion? Fighting AIDS not only helps those infected; it also makes good business sense. PMID:12577655

  17. The New Merit Aid

    ERIC Educational Resources Information Center

    Dynarski, Susan

    2004-01-01

    Merit aid, a discount to college costs contingent upon academic performance, is nothing new. Colleges and private organizations have long rewarded high-achieving, college-bound high school students with scholarships. While merit aid has a long history in the private sector, it has not played a major role in the public sector. At the state level,…

  18. [Epidemiology of AIDS].

    PubMed

    1988-02-01

    The World Health Organization (WHO) estimates that some 300,000 AIDS cases will be diagnosed by the end of 1988. As of December 1987, 128 countries had reported a total of 72,000 cases, about half the number of cases that actually occurred. The WHO estimates that some 5-10 million persons are already infected with HIV, so that the number of AIDS cases will increase rapidly for the next 5 years at least. The number of cases reported in Africa increased considerably in 1987, reflecting greater awareness of AIDS and greater efforts at control. By late 1987 WHO was working actively with over 100 countries to combat AIDS. An expert meeting organized by the WHO Special Program to Combat AIDS recommended to governments and prison administrators that condoms be provided to inmates and that treatment programs be provided for intravenous drug addicts. Prison personnel should receive education about HIV infection and AIDS. Incarceration policies, especially for drug addicts, should be reviewed in light of the AIDS epidemic. An estimated average of 10% of the 270,000 prisoners enumerated in 17 European countries are believed to be HIV positive, but the proportion increases to 26% in the highest risk countries. The proportion of seropositive subjects in general exceeds that in the total population. Prison and health officials will be obliged to assign increasing resources to AIDS in prisons in the years to come. PMID:3201571

  19. What about AIDS?

    ERIC Educational Resources Information Center

    Dreyfuss, Katharine R.

    1987-01-01

    Discusses the nature of Acquired Immune Deficiency Syndrome (AIDS). Suggests ways in which camp directors can establish procedures for making appropriate decisions about accepting campers/staff workers with AIDS. Reviews aspects of environmental sanitation, physical health, confidentiality, camper/staff drug use and sexual behavior, medical…

  20. Detecting Student Aid Fraud.

    ERIC Educational Resources Information Center

    Sheppard, Jeffrey

    1998-01-01

    Describes the varied kinds of student aid fraud found to be occurring within and outside colleges and universities, and examines implications for public policy on student aid programs. Discusses specific fraud cases and their outcomes, and makes suggestions for institutional action if student fraud is suspected. (MSE)

  1. Teachers with AIDS.

    ERIC Educational Resources Information Center

    Strope, John L., Jr.

    1988-01-01

    Discusses the application of Section 504 of the Rehabilitation Act of 1973 as a legal theory available to an employee of a public school system who faces isolation, transfer, suspension, or termination because of Acquired Immune Deficiency Syndrome (AIDS). Addresses AIDS in the workplace and the law. (MLF)

  2. AIDS Epidemiological models

    NASA Astrophysics Data System (ADS)

    Rahmani, Fouad Lazhar

    2010-11-01

    The aim of this paper is to present mathematical modelling of the spread of infection in the context of the transmission of the human immunodeficiency virus (HIV) and the acquired immune deficiency syndrome (AIDS). These models are based in part on the models suggested in the field of th AIDS mathematical modelling as reported by ISHAM [6].

  3. Preventing AIDS via Education.

    ERIC Educational Resources Information Center

    House, Reese M.; Walker, Catherine M.

    1993-01-01

    Compares the Acquired Immune Deficiency Syndrome (AIDS) epidemic to past epidemics, including social and political responses. Identifies populations at risk for human immunodeficiency virus (HIV) infection. Discusses current social and economic factors affecting AIDS education programs. Makes recommendations and identifies resources for starting…

  4. BIBLIOGRAPHY OF TRAINING AIDS.

    ERIC Educational Resources Information Center

    MCKEONE, CHARLES J.

    THIS COMPILATION OF INSTRUCTIONAL AIDS FOR USE IN AIR-CONDITIONING AND REFRIGERATION TRAINING PROGRAMS CONTAINS LISTS OF VISUAL AND AUDIOVISUAL TRAINING AIDS AND GUEST LECTURERS AVAILABLE FROM MEMBER COMPANIES OF THE AIR-CONDITIONING AND REFRIGERATION INSTITUTE AS AN INDUSTRY SERVICE TO SCHOOL OFFICIALS INTERESTED IN CONDUCTING SUCH PROGRAMS. THE…

  5. AIDS and Chemical Dependency.

    ERIC Educational Resources Information Center

    Pohl, Melvin I.

    After defining HIV and the AIDS disease and outlining symptoms and means of infection, this fact sheet lists the ways alcohol and drugs are involved with the AIDS epidemic, noting that needle-sharing transmits the virus; that alcohol or mood-altering drugs like crack cocaine cause disinhibition, increase sex drive, encourage sex for drugs, and…

  6. Implantable Heart Aid

    NASA Technical Reports Server (NTRS)

    1984-01-01

    CPI's human-implantable automatic implantable defibrillator (AID) is a heart assist system, derived from NASA's space circuitry technology, that can prevent erratic heart action known as arrhythmias. Implanted AID, consisting of microcomputer power source and two electrodes for sensing heart activity, recognizes onset of ventricular fibrillation (VF) and delivers corrective electrical countershock to restore rhythmic heartbeat.

  7. AIDS: an economic perspective.

    PubMed

    Squire, L

    1998-08-01

    Each country currently experiencing an AIDS epidemic did not believe that the epidemics would develop, but they did and more than 6 million people have since died. However, if the governments of the approximately 2.3 billion people who live in developing countries where HIV/AIDS has not yet spread to the general population, together with the international community and nongovernmental organizations, act promptly, many lives will be saved. The World Bank publication "Confronting AIDS: Public Priorities in a Global Epidemic" brings, for the first time, an economic perspective to the problem of AIDS. The author considers how developing country governments should respond to the AIDS epidemic when they also face so many other major and pressing problems related to raising more than 1 billion people out of severe poverty. While AIDS is an important problem which must be immediately addressed, using resources to help people with AIDS will come at the expense of other objectives such as sending children to school, providing safe drinking water, and building infrastructure. The serious nature of the HIV/AIDS epidemic and what governments should do are considered. PMID:12294026

  8. International Aid to Education

    ERIC Educational Resources Information Center

    Benavot, Aaron

    2010-01-01

    Recent evidence highlights several worrisome trends regarding aid pledges and disbursements, which have been exacerbated by the global financial crisis. First, while overall development assistance rose in 2008, after 2 years of decline, the share of all sector aid going to the education sector has remained virtually unchanged at about 12 percent…

  9. Aid, Development, and Education

    ERIC Educational Resources Information Center

    Klees, Steven J.

    2010-01-01

    The world faces pervasive poverty and inequality. Hundreds of billions of dollars in international aid have been given or loaned to developing countries though bilateral and multilateral mechanisms, at least, ostensibly, in order to do something about these problems. Has such aid helped? Debates around this question have been ongoing for decades,…

  10. Community responses to AIDS.

    PubMed

    Anderson, S

    1994-01-01

    Some examples of care in the community for people with HIV/AIDS are reported from Africa. Members of communities committed to fighting the AIDS epidemic cannot do so alone and should be given every possible help. Inadequate care favours the spread of HIV, as does the stigmatization of people with HIV infection and their families.

  11. AIDS Fact Pack.

    ERIC Educational Resources Information Center

    Center for Population Options, Washington, DC.

    The three fact sheets presented in this document address issues surrounding adolescent sexuality and sexually transmitted diseases (STDs), especially the Acquired Immune Deficiency Syndrome (AIDS). The first fact sheet, "Young Women and AIDS: A Worldwide Perspective," suggests that since open discussions of adolescent sexuality have long been…

  12. AIDS -- a modern hydra.

    PubMed

    Chen, D W

    1988-10-01

    So far, AIDS has not been a major problem in Taiwan. Only 79 people have tested HIV-seropositive, and only 6 have been stricken by the disease. The government has allocated money for AIDS research; blood screening is mandatory in all hospitals; confidential AIDS testing is widely available; and doctors are advised to administer azidothymidine to anyone who tests positive. Azidothymidine is not a cure, but it can prevent the virus from destroying more cells. Nevertheless, a climate of irrational fear of and ignorance about AIDS pervades Taiwan. Many people believe that AIDS can be transmitted by casual contact, and people who are HIV-seropositive are treated as social outcasts. One student at the University of Taipei, only a few credits from graduation, has been refused readmission to the university because he tested HIV-positive. Sex education in the schools is not a good route for AIDS education because sex and especially homosexuality are simply not mentioned in public in Taiwan. Activists, including gay-rights representative, Chi Chia-Wei, have turned to the mass media, especially television as a vehicle for AIDS education, and several programs on AIDS have been shown since 1986.

  13. Output order in immediate serial recall.

    PubMed

    Tan, Lydia; Ward, Geoff

    2007-07-01

    In two experiments, we examined the effect of output order in immediate serial recall (ISR). In Experiment 1, three groups of participants saw lists of eight words and wrote down the words in the rows corresponding to their serial positions in an eight-row response grid. One group was precued to respond in forward order, a second group was precued to respond in any order, and a third group was postcued for response order. There were significant effects of output order, but not of cue type. Relative to the forward output order, the free output order led to enhanced recency and diminished primacy, with superior performance for words output early in recall. These results were replicated in Experiment 2 using six-item lists, which further suggests that output order plays an important role in the primacy effect in ISR and that the recency items are most highly accessible at recall.

  14. Improvement of stress tolerance and leavening ability under multiple baking-associated stress conditions by overexpression of the SNR84 gene in baker's yeast.

    PubMed

    Lin, Xue; Zhang, Cui-Ying; Bai, Xiao-Wen; Feng, Bing; Xiao, Dong-Guang

    2015-03-16

    During the bread-making process, industrial baker's yeast cells are exposed to multiple baking-associated stresses, such as elevated high-temperature, high-sucrose and freeze-thaw stresses. There is a high demand for baker's yeast strains that could withstand these stresses with high leavening ability. The SNR84 gene encodes H/ACA snoRNA (small nucleolar RNA), which is known to be involved in pseudouridylation of the large subunit rRNA. However, the function of the SNR84 gene in baker's yeast coping with baking-associated stresses remains unclear. In this study, we explored the effect of SNR84 overexpression on baker's yeast which was exposed to high-temperature, high-sucrose and freeze-thaw stresses. These results suggest that overexpression of the SNR84 gene conferred tolerance of baker's yeast cells to high-temperature, high-sucrose and freeze-thaw stresses and enhanced their leavening ability in high-sucrose and freeze-thaw dough. These findings could provide a valuable insight for breeding of novel stress-resistant baker's yeast strains that are useful for baking.

  15. Improvement of stress tolerance and leavening ability under multiple baking-associated stress conditions by overexpression of the SNR84 gene in baker's yeast.

    PubMed

    Lin, Xue; Zhang, Cui-Ying; Bai, Xiao-Wen; Feng, Bing; Xiao, Dong-Guang

    2015-03-16

    During the bread-making process, industrial baker's yeast cells are exposed to multiple baking-associated stresses, such as elevated high-temperature, high-sucrose and freeze-thaw stresses. There is a high demand for baker's yeast strains that could withstand these stresses with high leavening ability. The SNR84 gene encodes H/ACA snoRNA (small nucleolar RNA), which is known to be involved in pseudouridylation of the large subunit rRNA. However, the function of the SNR84 gene in baker's yeast coping with baking-associated stresses remains unclear. In this study, we explored the effect of SNR84 overexpression on baker's yeast which was exposed to high-temperature, high-sucrose and freeze-thaw stresses. These results suggest that overexpression of the SNR84 gene conferred tolerance of baker's yeast cells to high-temperature, high-sucrose and freeze-thaw stresses and enhanced their leavening ability in high-sucrose and freeze-thaw dough. These findings could provide a valuable insight for breeding of novel stress-resistant baker's yeast strains that are useful for baking. PMID:25555226

  16. AFB's Computerized Travel Aid: Two Years of Research and Development.

    ERIC Educational Resources Information Center

    Uslan, Mark M.; And Others

    1983-01-01

    Progress on the computerized travel aid, an electronic device, using elements of the Polaroid Sonar Camera and a microprocessor, for visually handicapped persons is reviewed, and research on the effectiveness of various models noted. Recommended modifications touch on aspects of mounting, beam shape, and audible outputs. (CL)

  17. Multi-session complex averaging for high resolution high SNR 3T MR visualization of ex vivo hippocampus and insula

    NASA Astrophysics Data System (ADS)

    Stamm, Aymeric; Singh, Jolene M.; Scherrer, Benoit; Afacan, Onur; Warfield, Simon K.

    2015-03-01

    The hippocampus and the insula are responsible for episodic memory formation and retrieval. Hence, visualization of the cytoarchitecture of such structures is of primary importance to understand the underpinnings of conscious experience. Magnetic Resonance Imaging (MRI) offers an opportunity to non-invasively image these crucial structures. However, current clinical MR imaging operates at the millimeter scale while these anatomical landmarks are organized into sub-millimeter structures. For instance, the hippocampus contains several layers, including the CA3-dentate network responsible for encoding events and experiences. To investigate whether memory loss is a result of injury or degradation of CA3/dentate, spatial resolution must exceed one hundred micron, isotropic, voxel size. Going from one millimeter voxels to one hundred micron voxels results in a 1000× signal loss, making the measured signal close to or even way below the precision of the receiving coils. Consequently, the signal magnitude that forms the structural images will be biased and noisy, which results in inaccurate contrast and less than optimal signal-to-noise ratio (SNR). In this paper, we propose a strategy to perform high spatial resolution MR imaging of the hippocampus and insula with 3T scanners that enables accurate contrast (no systematic bias) and arbitrarily high SNR. This requires the collection of additional repeated measurements of the same image and a proper averaging of the k-space data in the complex domain. This comes at the cost of additional scan time, but long single-session scan times are not practical for obvious reasons. Hence, we also develop an approach to combine k-space data from multiple sessions, which enables the total scan time to be split into arbitrarily short sessions, where the patient is allowed to move and rest in-between. For validation, we hereby illustrate our multi-session complex averaging strategy by providing high spatial resolution 3T MR visualization

  18. New electrical plethysmograph monitors cardiac output

    NASA Technical Reports Server (NTRS)

    Kubicek, W. B.; Patterson, R. P.; Witsoe, D. A.

    1968-01-01

    Four-electrode impedance plethysmograph measures ventricular stroke volume of cardiac output of humans. The instrument is automatic, operates with only one recording channel, and minimizes patient discomfort.

  19. Exercise efficiency of low power output cycling.

    PubMed

    Reger, M; Peterman, J E; Kram, R; Byrnes, W C

    2013-12-01

    Exercise efficiency at low power outputs, energetically comparable to daily living activities, can be influenced by homeostatic perturbations (e.g., weight gain/loss). However, an appropriate efficiency calculation for low power outputs used in these studies has not been determined. Fifteen active subjects (seven females, eight males) performed 14, 5-min cycling trials: two types of seated rest (cranks vertical and horizontal), passive (motor-driven) cycling, no-chain cycling, no-load cycling, cycling at low (10, 20, 30, 40 W), and moderate (50, 60, 80, 100, 120 W) power outputs. Mean delta efficiency was 57% for low power outputs compared to 41.3% for moderate power outputs. Means for gross (3.6%) and net (5.7%) efficiencies were low at the lowest power output. At low power outputs, delta and work efficiency values exceeded theoretical values. In conclusion, at low power outputs, none of the common exercise efficiency calculations gave values comparable to theoretical muscle efficiency. However, gross efficiency and the slope and intercept of the metabolic power vs mechanical power output regression provide insights that are still valuable when studying homeostatic perturbations.

  20. Acoustical and Perceptual Comparison of Noise Reduction and Compression in Hearing Aids

    ERIC Educational Resources Information Center

    Brons, Inge; Houben, Rolph; Dreschler, Wouter A.

    2015-01-01

    Purpose: Noise reduction and dynamic-range compression are generally applied together in hearing aids but may have opposite effects on amplification. This study evaluated the acoustical and perceptual effects of separate and combined processing of noise reduction and compression. Design: Recordings of the output of 4 hearing aids for speech in…

  1. Electroacoustic Evaluation of Frequency-Modulated Receivers Interfaced with Personal Hearing Aids

    ERIC Educational Resources Information Center

    Schafer, Erin C.; Thibodeau, Linda M.; Whalen, Holly S.; Overson, Gary J.

    2007-01-01

    Purpose: The purpose of this study was to compare the electroacoustic outputs of frequency-modulated (FM) systems coupled to hearing aids. Method: Electroacoustic performance of FM systems coupled to hearing aids was determined for 3 FM receivers: body-worn with neck loop, ear-level nonprogrammable, and ear-level programmable. Systems were…

  2. Correlation of the genotoxic activation and kinetic properties of Salmonella enterica serovar Typhimurium nitroreductases SnrA and cnr with the redox potentials of nitroaromatic compounds and quinones.

    PubMed

    Salamanca-Pinzón, S G; Camacho-Carranza, R; Hernández-Ojeda, S L; Frontana-Uribe, B A; Espitia-Pinzón, C I; Espinosa-Aguirre, J J

    2010-05-01

    Bacterial nitroreductases (NRs) catalyse the oxygen-insensitive reduction of several nitro-substituted compounds and quinones. SnrA and cnr NRs have been previously identified in Salmonella enterica serovar Typhimurium; they reduce several environmental nitro compounds that display mutagenic activity in the Ames test. Although some of their biochemical properties have been reported, the substrate specificity of each protein over mutagenic nitro compounds is unknown; even more, the possible relationship between their capacity to activate nitro compounds into mutagens and the redox properties of putative substrates has been poorly investigated. We have purified SnrA and cnr and investigated their capacity to activate several mutagens in the Ames test as well as their kinetic parameters K(m) and V(max). Our results show that SnrA and cnr are able to activate 2,7-dinitrofluorene with the same efficiency and a similar mutagenic potency in the YG7132 tester strain; 1-nitropyrene and 1,3-dinitropyrene were efficiently activated by cnr, whereas 1,8-dinitropyrene, 1,6-dinitropyrene and 2-nitrofluorene were scarcely activated by either NR. The mutagenic potency of nitro compounds obtained in the presence of either enzyme correlates with their redox potential reported in the literature. On the other hand, a good correlation was obtained between the catalytic efficiency (V(max)/K(m)) of the purified cnr with the redox potential of eight molecules including nitro-substituted compounds and quinones. No correlation between redox potential and catalytic efficiency by SnrA was observed, suggesting that factors other than redox potential such as the structure of the compounds are involved in the catalytic efficiency of SnrA. PMID:20118186

  3. A CR-HYDRO-NEI MODEL OF MULTI-WAVELENGTH EMISSION FROM THE VELA JR. SUPERNOVA REMNANT (SNR RX J0852.0-4622)

    SciTech Connect

    Lee, Shiu-Hang; Nagataki, Shigehiro; Slane, Patrick O.; Patnaude, Daniel J.; Ellison, Donald C. E-mail: nagataki@yukawa.kyoto-u.ac.jp E-mail: dpatnaude@cfa.harvard.edu

    2013-04-10

    Based largely on energy budget considerations and the observed cosmic-ray (CR) ionic composition, supernova remnant (SNR) blast waves are the most likely sources of CR ions with energies at least up to the 'knee' near 10{sup 15} eV. Shocks in young shell-type TeV-bright SNRs are surely producing TeV particles, but the emission could be dominated by ions producing {pi}{sup 0}-decay emission or electrons producing inverse Compton gamma rays. Unambiguously identifying the GeV-TeV emission process in a particular SNR will not only help pin down the origin of CRs, it will also add significantly to our understanding of the diffusive shock acceleration (DSA) mechanism and improve our understanding of supernovae and the impact SNRs have on the circumstellar medium. In this study, we investigate the Vela Jr. SNR, an example of TeV-bright non-thermal SNRs. We perform hydrodynamic simulations coupled with nonlinear DSA and non-equilibrium ionization near the forward shock to confront currently available multi-wavelength data. We find, with an analysis similar to that used earlier for SNR RX J1713.7-3946, that self-consistently modeling the thermal X-ray line emission with the non-thermal continuum in our one-dimensional model strongly constrains the fitting parameters, and this leads convincingly to a leptonic origin for the GeV-TeV emission for Vela Jr. This conclusion is further supported by applying additional constraints from observation, including the radial brightness profiles of the SNR shell in TeV gamma rays, and the spatial variation of the X-ray synchrotron spectral index. We will discuss implications of our models on future observations by the next-generation telescopes.

  4. Effects of synthetic speech output and orthographic feedback on spelling in a student with autism: a preliminary study.

    PubMed

    Schlosser, R W; Blischak, D M; Belfiore, P J; Bartley, C; Barnett, N

    1998-08-01

    The effects of speech output and orthographic feedback on spelling performance were evaluated in this preliminary study. A nonspeaking student with autism was taught to spell words under three feedback conditions using a voice output communication aid. In the auditoryvisual condition, the participant received speech output and orthographic feedback. In the visual condition, the participant received only the orthographic feedback. In the auditory condition, the student received only speech output. An adapted alternating treatments design was used to evaluate the effects of the three feedback conditions. Although the participant reached criterion and maintained performance in each of the conditions, the provision of speech output alone and in combination with orthographic feedback resulted in more efficient spelling than the provision of orthographic feedback alone. Although replications with other subjects are necessary, findings suggest that speech output contributes to efficient spelling.

  5. Health care and AIDS.

    PubMed

    Peck, J; Bezold, C

    1992-07-01

    The acquired immune deficiency syndrome (AIDS) is a harbinger for change in health care. There are many powerful forces poised to transform the industrialized health care structure of the twentieth century, and AIDS may act as either a catalyst or an amplifier for these forces. AIDS could, for example, swamp local resources and thereby help trigger national reform in a health care system that has already lost public confidence. AIDS can also hasten the paradigm shift that is occurring throughout health care. Many of the choices society will confront when dealing with AIDS carry implications beyond health care. Information about who has the disease, for example, already pits traditional individual rights against group interests. Future information systems could make discrimination based upon medical records a nightmare for a growing number of individuals. Yet these systems also offer the hope of accelerated progress against not only AIDS but other major health threats as well. The policy choices that will define society's response to AIDS can best be made in the context of a clearly articulated vision of a society that reflects our deepest values. PMID:10119289

  6. HIV / AIDS and tourism.

    PubMed

    Forsythe, S

    1999-01-01

    Since it tends to be significantly affected by HIV/AIDS, the tourism sector is a likely target for HIV/AIDS interventions in many countries. The tourist industry is at particular risk from the pandemic because of the mobility of the work force, the presence of sex tourists, and the heavy reliance of many countries upon tourism revenues. Indeed, tourism is one of the largest and fastest growing industries in many countries. Some people have speculated that potential tourists' fear of AIDS could discourage them from visiting certain countries, while others have even suggested that tourism should be discouraged because the industry contributes to the spread of HIV/AIDS. When traveling, tourists often take risks that they would not take at home. They tend to drink more, use drugs more, and be generally more adventurous while on holiday. Such adventures often include taking sexual risks. When tourists have sex with prostitutes, hotel staff, and others in the local population, a bridge can be created for HIV to cross back and forth between the tourist's home country and the tourist destination. The author reviews selected studies on the relationship between HIV/AIDS and tourism. Overall, the existing literature offers no definitive evidence that AIDS has had any lasting impact upon the tourism industry anywhere in the world. Rather, promoting a healthy tourism industry and HIV/AIDS prevention are likely complementary in many ways. PMID:12349153

  7. Hearing Aids and Music

    PubMed Central

    Chasin, Marshall; Russo, Frank A.

    2004-01-01

    Historically, the primary concern for hearing aid design and fitting is optimization for speech inputs. However, increasingly other types of inputs are being investigated and this is certainly the case for music. Whether the hearing aid wearer is a musician or merely someone who likes to listen to music, the electronic and electro-acoustic parameters described can be optimized for music as well as for speech. That is, a hearing aid optimally set for music can be optimally set for speech, even though the converse is not necessarily true. Similarities and differences between speech and music as inputs to a hearing aid are described. Many of these lead to the specification of a set of optimal electro-acoustic characteristics. Parameters such as the peak input-limiting level, compression issues—both compression ratio and knee-points—and number of channels all can deleteriously affect music perception through hearing aids. In other cases, it is not clear how to set other parameters such as noise reduction and feedback control mechanisms. Regardless of the existence of a “music program,” unless the various electro-acoustic parameters are available in a hearing aid, music fidelity will almost always be less than optimal. There are many unanswered questions and hypotheses in this area. Future research by engineers, researchers, clinicians, and musicians will aid in the clarification of these questions and their ultimate solutions. PMID:15497032

  8. HIV / AIDS and tourism.

    PubMed

    Forsythe, S

    1999-01-01

    Since it tends to be significantly affected by HIV/AIDS, the tourism sector is a likely target for HIV/AIDS interventions in many countries. The tourist industry is at particular risk from the pandemic because of the mobility of the work force, the presence of sex tourists, and the heavy reliance of many countries upon tourism revenues. Indeed, tourism is one of the largest and fastest growing industries in many countries. Some people have speculated that potential tourists' fear of AIDS could discourage them from visiting certain countries, while others have even suggested that tourism should be discouraged because the industry contributes to the spread of HIV/AIDS. When traveling, tourists often take risks that they would not take at home. They tend to drink more, use drugs more, and be generally more adventurous while on holiday. Such adventures often include taking sexual risks. When tourists have sex with prostitutes, hotel staff, and others in the local population, a bridge can be created for HIV to cross back and forth between the tourist's home country and the tourist destination. The author reviews selected studies on the relationship between HIV/AIDS and tourism. Overall, the existing literature offers no definitive evidence that AIDS has had any lasting impact upon the tourism industry anywhere in the world. Rather, promoting a healthy tourism industry and HIV/AIDS prevention are likely complementary in many ways.

  9. Solidarity and AIDS: introduction.

    PubMed

    Krieger, N

    1991-01-01

    Perhaps more than any other disease in recent history, AIDS has taught a cruel and crucial lesson: the constraints on our response to this epidemic are as deep as our denial, as entrenched as the inequities that permeate our society, as circumscribed as our knowledge, and as unlimited as our compassion and our commitment to human rights. Elaborating on these themes, the final three articles in this Special Section on AIDS consider three widely divergent yet intimately connected topics: AIDS in Cuba, AIDS in Brazil, and global AIDS prevention in the 1990s. Together, they caution that if we persist in treating AIDS as a problem only of "others," no country will be spared the social and economic devastation that promises to be the cost of our contempt and our folly. Solidarity is not an option; it is a necessity. Without conscious recognition of the worldwide relationship between health, human rights, and social inequalities, our attempts to abate the spread of AIDS--and to ease the suffering that follows in its wake--most surely will fall short of our goals. Finally, as we mourn our dead, we must take to heart the words of Mother Jones, and "fight like hell for living." This is the politics of survival.

  10. AIDS Training in the Workplace.

    ERIC Educational Resources Information Center

    Vest, Jusanne M.; And Others

    1991-01-01

    Management training regarding Acquired Immune Deficiency Syndrome (AIDS) begins with three needs assessment tools--instruments measuring fear of AIDS, knowledge of AIDS, and beliefs about the business consequences of the disease. (SK)

  11. HIV/AIDS and Alcohol

    MedlinePlus

    ... Psychiatric Disorders Other Substance Abuse HIV/AIDS HIV/AIDS Human immunodeficiency virus (HIV) targets the body’s immune ... and often leads to acquired immune deficiency syndrome (AIDS). Each year in the United States, between 55, ...

  12. Research Report: HIV/AIDS

    MedlinePlus

    ... Reports » HIV/AIDS » Letter from the Director HIV/AIDS Email Facebook Twitter Letter from the Director Human ... the virus that causes acquired immune deficiency syndrome (AIDS) — has been with us for three decades now. ...

  13. HIV / AIDS: An Unequal Burden

    MedlinePlus

    ... Navigation Bar Home Current Issue Past Issues HIV / AIDS HIV / AIDS: An Unequal Burden Past Issues / Summer 2009 Table ... Victoria Cargill talks to students about HIV and AIDS at the opening of a National Library of ...

  14. AIDS in Malaysia.

    PubMed

    Singh, J; Che'Rus, S; Chong, S; Chong, Y K; Crofts, N

    1994-01-01

    The first people to be infected with HIV in Malaysia were mainly homosexual men with foreign connections. IV drug users, however, rapidly became the population group with the highest prevalence of HIV. Accurate, timely data are needed in order to responsibly describe the pattern of HIV infection and AIDS in any given setting. In Malaysia, however, there has been little systematic surveillance in population groups other than blood donors. This surveillance indicates the existence of a rapidly increasing rate of seropositivity among blood donors. Otherwise, many people are loathe to undergo voluntary HIV testing to determine their serostatus. Moreover, some people with STDs avoid contact with the health system and the potential for HIV testing. The extent to which AIDS cases are underreported or reported late is unknown. On the other hand, an estimated 10% of notified AIDS cases have been wrongly classified as such. The lack of hard data on HIV/AIDS in Malaysia makes it difficult to project the future course of the epidemic in the country. Since Malaysia shares a land border with Thailand and there is much sea-borne traffic between the two countries, it is highly possible that Malaysia will experience a significant epidemic of HIV infection similar to its neighbors. A National AIDS Committee was established April 1985 to develop responses to the HIV epidemic, while the National AIDS Program Manager of the Ministry of Health is responsible for controlling STDs. A national plan of action for the prevention and control of AIDS, drawn up in 1985 and revised in 1988, includes planning for the continued surveillance of HIV infection and AIDS through existing notification systems, and for screening and sentinel programs for IV drug users, prostitutes, and STD patients. Recent nongovernmental organization responses complement government efforts to prevent HIV and AIDS in Malaysia. PMID:7857575

  15. Latina women and AIDS.

    PubMed

    Worth, D; Rodriguez, R

    1987-01-01

    The incidence of AIDS in Latina women is over 11 times that of white women. Women account for 13% of all Latino AIDS deaths since 1980. This examination of the impact of AIDS on Latino women concentrates on Manhattan's Lower East Side. The AIDS deaths among Puerto Rican women in this neighborhood are predominantly intravenous drug abuse related. Latina women accounted for more than 1/2 of all female AIDS deaths on the Lower East Side during the 1980-1985 period. The age range is parallel with that in the rest of New York City, with the exception of a higher number of deaths on the Lower East Side in the age ranges of 15-19 and over 40. Serious obstacles exist to providing AIDS risk reduction information to Puerto Rican women and their partners. Latinos account for 11% of all US AIDS cases among gay and bisexual men. The cultural proscription against these sexual practices in the Puerto Rican community makes AIDS education related to such practices extremely difficult. Many of the female sex partners of these men are unaware of their bisexuality, and, therefore not aware that they are at risk of HIV infection. The Latina women most at risk are young, poor, and have low educational levels. Latina women seriously underutilize ongoing primary health care, family planning, prenatal or pediatric care. Attempts to reach Latina women with AIDS risk reduction education must also contend with issues such as cultural gender roles. Females tend to be dependent on males and defer to male decision making related to sexual practices. In formulating policy regarding services and education, it is essential to involve the leadership of the Latino community. PMID:12268416

  16. Infrared imaging and polarimetric observations of the pulsar wind nebula in SNR G21.5-0.9

    NASA Astrophysics Data System (ADS)

    Zajczyk, A.; Gallant, Y. A.; Slane, P.; Reynolds, S. P.; Bandiera, R.; Gouiffès, C.; Le Floc'h, E.; Comerón, F.; Koch Miramond, L.

    2012-06-01

    We present infrared observations of the supernova remnant G21.5-0.9 with the Very Large Telescope, the Canada-France-Hawaii Telescope and the Spitzer Space Telescope. Using the VLT/ISAAC camera equipped with a narrow-band [Fe II] 1.64 μm filter the entire pulsar wind nebula in SNR G21.5-0.9 was imaged. This led to detection of iron line-emitting material in the shape of a broken ring-like structure following the nebula's edge. The detected emission is limb-brightened. We also detect the compact nebula surrounding PSR J1833-1034, both through imaging with the CFHT/AOB-KIR instrument (K' band) and the IRAC camera (all bands) and also through polarimetric observations performed with VLT/ISAAC (Ks band). The emission from the compact nebula is highly polarised with an average value of the linear polarisation fraction PL^avg ≃ 0.47, and the swing of the electric vector across the nebula can be observed. The infrared spectrum of the compact nebula can be described as a power law of index αIR = 0.7 ± 0.3, and suggests that the spectrum flattens between the infrared and X-ray bands.

  17. Wiener filtering of surface EMG with a priori SNR estimation toward myoelectric control for neurological injury patients.

    PubMed

    Liu, Jie; Ying, Dongwen; Zhou, Ping

    2014-12-01

    Voluntary surface electromyogram (EMG) signals from neurological injury patients are often corrupted by involuntary background interference or spikes, imposing difficulties for myoelectric control. We present a novel framework to suppress involuntary background spikes during voluntary surface EMG recordings. The framework applies a Wiener filter to restore voluntary surface EMG signals based on tracking a priori signal to noise ratio (SNR) by using the decision-directed method. Semi-synthetic surface EMG signals contaminated by different levels of involuntary background spikes were constructed from a database of surface EMG recordings in a group of spinal cord injury subjects. After the processing, the onset detection of voluntary muscle activity was significantly improved against involuntary background spikes. The magnitude of voluntary surface EMG signals can also be reliably estimated for myoelectric control purpose. Compared with the previous sample entropy analysis for suppressing involuntary background spikes, the proposed framework is characterized by quick and simple implementation, making it more suitable for application in a myoelectric control system toward neurological injury rehabilitation. PMID:25443536

  18. Wiener Filtering of Surface EMG with a priori SNR Estimation Toward Myoelectric Control for Neurological Injury Patients

    PubMed Central

    Liu, Jie; Ying, Dongwen; Zhou, Ping

    2014-01-01

    Voluntary surface electromyogram (EMG) signals from neurological injury patients are often corrupted by involuntary background interference or spikes, imposing difficulties for myoelectric control. We present a novel framework to suppress involuntary background spikes during voluntary surface EMG recordings. The framework applies a Wiener filter to restore voluntary surface EMG signals based on tracking a priori signal to noise ratio (SNR) by using the decision-directed method. Semi-synthetic surface EMG signals contaminated by different levels of involuntary background spikes were constructed from a database of surface EMG recordings in a group of spinal cord injury subjects. After the processing, the onset detection of voluntary muscle activity was significantly improved against involuntary background spikes. The magnitude of voluntary surface EMG signals can also be reliably estimated for myoelectric control purpose. Compared with the previous sample entropy analysis for suppressing involuntary background spikes, the proposed framework is characterized by quick and simple implementation, making it more suitable for application in a myoelectric control system toward neurological injury rehabilitation. PMID:25443536

  19. Implantable Heart Aid

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Medrad utilized NASA's Apollo technology to develop a new device called the AID implantable automatic pulse generator which monitors the heart continuously, recognizes the onset of ventricular fibrillation and delivers a corrective electrical shock. AID pulse generator is, in effect, a miniaturized version of the defibrillator used by emergency squads and hospitals to restore rhythmic heartbeat after fibrillation, but has the unique advantage of being permanently available to the patient at risk. Once implanted, it needs no specially trained personnel or additional equipment. AID system consists of a microcomputer, a power source and two electrodes which sense heart activity.

  20. AIDS and public health.

    PubMed

    Moskop, J C

    1988-01-01

    After briefly stating the significance of acquired immunodeficiency syndrome (AIDS) for public health, this paper considers programs or proposals to control the spread of AIDS in the following eight general areas: (a) education; (b) distribution of sterile needles; (c) screening and treatment of blood, blood products, and other tissues; (d) voluntary and mandatory screening of persons for evidence of infection; (e) reporting; (f) contact tracing; (g) isolation and other restrictions on freedom of movement or association; and (h) physical marking of persons with AIDS. Significant moral issues within each of these areas are discussed, and the overall justifiability of various proposals is examined.

  1. Pulmonary complications of AIDS: radiologic features. [AIDS

    SciTech Connect

    Cohen, B.A.; Pomeranz, S.; Rabinowitz, J.G.; Rosen, M.J.; Train, J.S.; Norton, K.I.; Mendelson, D.S.

    1984-07-01

    Fifty-two patients with pulmonary complications of acquired immunodeficiency syndrome (AIDS) were studied over a 3-year period. The vast majority of the patients were homosexual; however, a significant number were intravenous drug abusers. Thirteen different organisms were noted, of which Pneumocystis carinii was by far the most common. Five patients had neoplasia. Most patients had initial abnormal chest films; however, eight patients subsequently shown to have Pneumocystis carinii pneumonia had normal chest films. A significant overlap in chest radiographic findings was noted among patients with different or multiple organisms. Lung biopsy should be an early consideration for all patients with a clinical history consistent with the pulmonary complications of AIDS. Of the 52 patients, 41 had died by the time this report was completed.

  2. Power output measurement during treadmill cycling.

    PubMed

    Coleman, D A; Wiles, J D; Davison, R C R; Smith, M F; Swaine, I L

    2007-06-01

    The study aim was to consider the use of a motorised treadmill as a cycling ergometry system by assessing predicted and recorded power output values during treadmill cycling. Fourteen male cyclists completed repeated cycling trials on a motorised treadmill whilst riding their own bicycle fitted with a mobile ergometer. The speed, gradient and loading via an external pulley system were recorded during 20-s constant speed trials and used to estimate power output with an assumption about the contribution of rolling resistance. These values were then compared with mobile ergometer measurements. To assess the reliability of measured power output values, four repeated trials were conducted on each cyclist. During level cycling, the recorded power output was 257.2 +/- 99.3 W compared to the predicted power output of 258.2 +/- 99.9 W (p > 0.05). For graded cycling, there was no significant difference between measured and predicted power output, 268.8 +/- 109.8 W vs. 270.1 +/- 111.7 W, p > 0.05, SEE 1.2 %. The coefficient of variation for mobile ergometer power output measurements during repeated trials ranged from 1.5 % (95 % CI 1.2 - 2.0 %) to 1.8 % (95 % CI 1.5 - 2.4 %). These results indicate that treadmill cycling can be used as an ergometry system to assess power output in cyclists with acceptable accuracy.

  3. Computer Output Microfilm and Library Catalogs.

    ERIC Educational Resources Information Center

    Meyer, Richard W.

    Early computers dealt with mathematical and scientific problems requiring very little input and not much output, therefore high speed printing devices were not required. Today with increased variety of use, high speed printing is necessary and Computer Output Microfilm (COM) devices have been created to meet this need. This indirect process can…

  4. DIST/AVC Out-Put Definition.

    ERIC Educational Resources Information Center

    Wilkinson, Gene L.

    The first stage of development of a management information system for DIST/AVC (Division of Instructional Technology/Audio-Visual Center) is the definition of out-put units. Some constraints on the definition of output units are: 1) they should reflect goals of the organization, 2) they should reflect organizational structure and procedures, and…

  5. Reinvestigating the Noticing Function of Output

    ERIC Educational Resources Information Center

    Uggen, Maren S.

    2012-01-01

    A conceptual replication of Izumi and Bigelow's research, this study used multiple measures to investigate second language (L2) learners' processes in output-input-output sequences. Specifically, it examined whether producing the target language impacts learners' attention to L2 structures in subsequent input. Thirty learners of English as a…

  6. Output beam analysis of high power COIL

    NASA Astrophysics Data System (ADS)

    Yu, Deli; Sang, Fengting; Jin, Yuqi; Sun, Yizhu

    2003-03-01

    As the output power of a chemical oxygen iodine laser (COIL) increases, the output laser beam instability appears as the far-field beam spot drift and deformation for the large Fresnel number unstable resonator. In order to interpret this phenomenon, an output beam mode simulation code was developed with the fast Fourier transform method. The calculation results show that the presence of the nonuniform gain in COIL produces a skewed output intensity distribution, which causes the mirror tilt and bulge due to the thermal expansion. With the output power of COIL increases, the mirror surfaces, especially the back surface of the scraper mirror, absorb more and more heat, which causes the drift and deformation of far field beam spot seriously. The initial misalignment direction is an important factor for the far field beam spot drifting and deformation.

  7. Nonlinearities in Magnetostrictive Transducer Dynamic Output

    NASA Astrophysics Data System (ADS)

    Flatau, Alison; Faidley, L. E.; Calkins, F. T.; Dapino, M. J.

    1997-03-01

    We have designed a magnetostrictive transducer for use in characterizing material properties of 11.5 cm long by 1.27 cm diameter cylindrical samples of the magnetostrictive material Terfenol-D. The material studied is a commercially available Terfenol-D, made using a modified Brigman manufacturing process. Output displacements in the stiffness controlled portion of the transducer's dynamic range (as loaded, up to 1000 Hz) were measured using a LVDT. Trends in output were observed as controlled changes in operating conditions were made. Excitation frequency, amplitude of magnetic excitation, and prestress were varied independently as other operating conditions (including temperature, mass load, and magnetic bias) were held fixed. Data are presented demonstrating distinct nonlinearities associated with a monotonic decrease in output with increased excitation frequency, a monotonic increase in output with increased excitation amplitude, and an initial increase followed by a decrease in output with increased prestress.

  8. AIDS.gov

    MedlinePlus

    ... Hospitalization and Palliative Care Friends & Family Dating and Marriage Family Planning Mixed-Status Couples Discrimination Legal Issues ... October 15th observance calls attention to the disproportionate impact of HIV/AIDS on the Latinx community. The ...

  9. Hearing Aid Tester

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Hearing aids often develop malfunctions that are not detected by the wearer. This is particularly true when the wearers are school-age children. Studies of selected groups showed that from 30 to more than 50 percent of school children were not getting adequate benefit from their hearing aids because of unrecognized malfunctions, usually low or dead batteries. This can be serious because hearing impairment retards a child's educational progress. NASA technology incorporated in the Hearing Aid Malfunction Detection Unit (HAMDU), the device pictured, is expected to provide an effective countermeasure to the childrens' hearing aid problem. A patent license has been awarded to a minority-owned firm, Hopkins International Company, a subsidiary of H. H. Aerospace Design Co., Inc., Elmford, New York. The company plans early commercial availability of its version of the device.

  10. HIV and AIDS

    MedlinePlus

    ... that causes the disease AIDS. HIV Hurts the Immune System People who are HIV positive have been tested ... to everyone in the world. When the person's immune system has weakened and more of the blood's T ...

  11. Types of Hearing Aids

    MedlinePlus

    ... They also have greater flexibility in hearing aid programming so that the sound they transmit can be ... 10903 New Hampshire Avenue Silver Spring, MD 20993 1-888-INFO-FDA (1-888-463-6332) Contact ...

  12. First Aid and Safety

    MedlinePlus

    ... First-Aid Kit Food Safety for Your Family Gun Safety Halloween Candy Hints Household Safety Checklists Household ... Climbing, and Grabbing Household Safety: Preventing Injuries From Firearms Household Safety: Preventing Injuries in the Crib Household ...

  13. AIDS: A National Dilemma.

    ERIC Educational Resources Information Center

    Issues in Science and Technology, 1987

    1987-01-01

    Contains excerpts from a special study on the AIDS epidemic by the Institute of Medicine and National Academy of Sciences. Presents an overview of the problem, outlines educational needs and public health measures, and identifies future research needs. (ML)

  14. Computer-aided diagnosis in thoracic CT

    NASA Astrophysics Data System (ADS)

    Li, Qiang

    2009-10-01

    Computer-aided diagnosis (CAD) provides a computer output as a "second opinion" in order to assist radiologists in the diagnosis of various diseases on medical images. Currently, a hot topic in CAD is the development of computerized schemes for detection of lung abnormalities, such as lung nodule and interstitial lung disease, in computed tomography (CT) images. The author describes in this article the current status of the CAD schemes for the detection of lung nodules and interstitial lung disease in CT developed by the author and his colleagues at the University of Chicago and Duke University.

  15. AIDS: the hidden enemy.

    PubMed

    Tinker, J; Sabatier, R

    1987-01-01

    This article discusses the acquired immunodeficiency syndrome (AIDS) epidemic an its effect on developing countries, with emphasis on Africa. The AIDS death toll will be high in the US: 180,000 by 1991, but it will be in the millions in developing countries. In Africa, AIDS is mainly transmitted heterosexually, is as prevalent among women as among men, and is taking a serious toll among professional classes and young wage earners. The social costs of funerals has increased, and company clinics and sick pay funds have been overwhelmed. In Uganda, the epidemic adds to the state of psychological shock people have sufferred because of the civil war. Medical professionals have been hard-pressed to acquire equipment for testing blood for the virus, although there have been efforts to protect blood supplies through exhaustive testing. Endemic tuberculosis becomes an even more serious problem in developing countries, since AIDS lowers resistance to it. AIDS also effects many developing country children, usually through infected mothers, who can transmit AIDS through breast milk or during pregnancy of birth. This poses a dilemma for promoters of breastfeeding. It is also feared that innoculation of immunosuppressed children may be dangerous. The global picture suggests that Africa is hardest hit: seropositivity prevalence ranges from 0.7% of Congo blood donors to 33% of male donors in Lusaka Zambia. Brazil's cases are mainly homosexual, and in Asia the prevalence is mostly low, although there is a great potential danger in countries where prostitution and heroin addiction are prevalent. The only effective weapon against AIDS is education and blood testing to prevent spread. Despite good education programs in some countries, e.g. Rwanda, there is still widespread ignorance of how AIDS is spread. PMID:12314457

  16. [AIDS and society].

    PubMed

    Koupernik, C

    1988-03-01

    On the basis of information gathered from media the writer delineates the following aspects of the impact of AIDS upon social life: advertising the danger, sex education of the youth, purposeful contamination by AIDS-patients, legal repressive measures, the doctors and the right to test, Anglican Church and acceptance of homosexuality among ministers, antagonistic incentives epidemiologic research and the right to confidentiality. Finally, he endorses the recent declaration of the America Psychiatric Association determined to fight discrimination and refusal of care.

  17. Digitally reconfigurable binary coded terahertz metamaterial with output analogous to NOR and AND

    NASA Astrophysics Data System (ADS)

    Ho, Chong Pei; Pitchappa, Prakash; Lee, Chengkuo

    2016-04-01

    We experimentally demonstrate a digitally reconfigurable binary coded terahertz metamaterial in the Terahertz (THz) frequency with the transmission output analogous to NOR and AND logic. An electric split-ring resonator with a released central arms is used as the switchable meta-bit. Isolation of controls in adjacent meta-bits allows for three distinct reconfiguration states of the metamaterial with the output analogous to NOR and AND at 0.26 THz and 0.36 THz, respectively. Further enhancement in controllability at the unit cell level will aid in the development of dynamically programmable metamaterial operating in the transmission mode for THz frequencies.

  18. AIDS in Africa.

    PubMed

    Wilson, D; Armstrong, M; Lavelle, S

    1991-01-01

    Works on epidemiological, and social and behavioral science aspects of AIDS prevention and support in Africa are reviewed from the 7th Conference on AIDS. Participants were especially concerned with why AIDS spreads at disparate rates in different countries and regions of the world. Research on the casual factors of the spread of HIV generally focused upon patterns of sex behavior, the presence of other STDs, and the effect of circumcision. The roles of certain vaginal tightening agents used by Zairian prostitutes, vaginal bruising and bleeding, sex during menses, and oral contraception were also considered. Further, participants explored the possibility of a more coordinated, integrated approach to research and intervention development between the medical and social disciplines, and expressed the overall need for concurrent mass education interventions. In the face of ever increasing rates of HIV infection, including vertical transmission, making condoms ubiquitous, affordable, and highly publicized should garner higher general acceptance and use rates in these populations. Papers and models on the micro- and macro-socioeconomic impact of AIDS were finally discussed, followed by recommendations for a complete reassessment and reworking of policy for AIDS prevention. AIDS activities should, in fact, be integrated into the daily fabric of society, with prevention measures considered an ultimate necessity for social survival.

  19. AIDS and haemophilia.

    PubMed

    Carr, R

    1985-01-01

    Approximately 1% of all AIDS cases are haemophiliacs. LAV/HTLV-III is transmitted by blood and in factor VIII concentrates. Since 1981, increasing numbers of haemophiliacs have been infected, as indicated by detection of antibodies to LAV/HTLV-III. Up to 90% of haemophiliacs in some populations are now seropositive, but to date less than 1% have progressed to clinical AIDS. Immunological abnormalities, in particular reduced T-lymphocyte helper/suppressor ratios, are common in haemophiliacs treated with factor VIII. Such abnormalities do not necessarily indicate past infection by the AIDS virus, but they may predispose to infection following exposure to the virus. Blood Transfusion agencies are introducing screening tests for antibodies to LAV/HTLV-III to help prevent the spread of AIDS by blood products. Heat treated factor VIII concentrate is now available and appears not to transmit AIDS. Factor IX concentrate may also transmit LAV/HTLV-III, but less frequently. A few cases of AIDS have occurred in Haemophilia B (Christmas Disease) patients.

  20. High Output Piezo/Triboelectric Hybrid Generator

    PubMed Central

    Jung, Woo-Suk; Kang, Min-Gyu; Moon, Hi Gyu; Baek, Seung-Hyub; Yoon, Seok-Jin; Wang, Zhong-Lin; Kim, Sang-Woo; Kang, Chong-Yun

    2015-01-01

    Recently, piezoelectric and triboelectric energy harvesting devices have been developed to convert mechanical energy into electrical energy. Especially, it is well known that triboelectric nanogenerators have a simple structure and a high output voltage. However, whereas nanostructures improve the output of triboelectric generators, its fabrication process is still complicated and unfavorable in term of the large scale and long-time durability of the device. Here, we demonstrate a hybrid generator which does not use nanostructure but generates much higher output power by a small mechanical force and integrates piezoelectric generator into triboelectric generator, derived from the simultaneous use of piezoelectric and triboelectric mechanisms in one press-and-release cycle. This hybrid generator combines high piezoelectric output current and triboelectric output voltage, which produces peak output voltage of ~370 V, current density of ~12 μA·cm−2, and average power density of ~4.44 mW·cm−2. The output power successfully lit up 600 LED bulbs by the application of a 0.2 N mechanical force and it charged a 10 μF capacitor to 10 V in 25 s. Beyond energy harvesting, this work will provide new opportunities for developing a small, built-in power source in self-powered electronics such as mobile electronics. PMID:25791299

  1. High output piezo/triboelectric hybrid generator.

    PubMed

    Jung, Woo-Suk; Kang, Min-Gyu; Moon, Hi Gyu; Baek, Seung-Hyub; Yoon, Seok-Jin; Wang, Zhong-Lin; Kim, Sang-Woo; Kang, Chong-Yun

    2015-03-20

    Recently, piezoelectric and triboelectric energy harvesting devices have been developed to convert mechanical energy into electrical energy. Especially, it is well known that triboelectric nanogenerators have a simple structure and a high output voltage. However, whereas nanostructures improve the output of triboelectric generators, its fabrication process is still complicated and unfavorable in term of the large scale and long-time durability of the device. Here, we demonstrate a hybrid generator which does not use nanostructure but generates much higher output power by a small mechanical force and integrates piezoelectric generator into triboelectric generator, derived from the simultaneous use of piezoelectric and triboelectric mechanisms in one press-and-release cycle. This hybrid generator combines high piezoelectric output current and triboelectric output voltage, which produces peak output voltage of ~370 V, current density of ~12 μA · cm(-2), and average power density of ~4.44 mW · cm(-2). The output power successfully lit up 600 LED bulbs by the application of a 0.2 N mechanical force and it charged a 10 μF capacitor to 10 V in 25 s. Beyond energy harvesting, this work will provide new opportunities for developing a small, built-in power source in self-powered electronics such as mobile electronics.

  2. High Output Piezo/Triboelectric Hybrid Generator

    NASA Astrophysics Data System (ADS)

    Jung, Woo-Suk; Kang, Min-Gyu; Moon, Hi Gyu; Baek, Seung-Hyub; Yoon, Seok-Jin; Wang, Zhong-Lin; Kim, Sang-Woo; Kang, Chong-Yun

    2015-03-01

    Recently, piezoelectric and triboelectric energy harvesting devices have been developed to convert mechanical energy into electrical energy. Especially, it is well known that triboelectric nanogenerators have a simple structure and a high output voltage. However, whereas nanostructures improve the output of triboelectric generators, its fabrication process is still complicated and unfavorable in term of the large scale and long-time durability of the device. Here, we demonstrate a hybrid generator which does not use nanostructure but generates much higher output power by a small mechanical force and integrates piezoelectric generator into triboelectric generator, derived from the simultaneous use of piezoelectric and triboelectric mechanisms in one press-and-release cycle. This hybrid generator combines high piezoelectric output current and triboelectric output voltage, which produces peak output voltage of ~370 V, current density of ~12 μA.cm-2, and average power density of ~4.44 mW.cm-2. The output power successfully lit up 600 LED bulbs by the application of a 0.2 N mechanical force and it charged a 10 μF capacitor to 10 V in 25 s. Beyond energy harvesting, this work will provide new opportunities for developing a small, built-in power source in self-powered electronics such as mobile electronics.

  3. Design of hydraulic output Stirling engine

    NASA Technical Reports Server (NTRS)

    Toscano, W. M.; Harvey, A. C.; Lee, K.

    1983-01-01

    A hydraulic output system for the RE-1000 free piston stirling engine (FPSE) was designed. The hydraulic output system can be readily integrated with the existing hot section of RE-1000 FPSE. The system has two simply supported diaphragms which separate the engine gas from the hydraulic fluid, a dynamic balance mechanism, and a novel, null center band hydraulic pump. The diaphragms are designed to endure more than 10 billion cycles, and to withstand the differential pressure load as high as 14 MPa. The projected thermodynamic performance of the hydraulic output version of RE-1000 FPSE is 1.87 kW at 29/7 percent brake efficiency.

  4. High Energy Output Marx Generator Design

    SciTech Connect

    Monty Lehmann

    2011-07-01

    High Energy Output Marx Generator Design a design of a six stage Marx generator that has a unipolar pulse waveform of 200 kA in a 50×500 microsecond waveform is presented. The difficulties encountered in designing the components to withstand the temperatures and pressures generated during the output pulse are discussed. The unique methods and materials used to successfully overcome these problems are given. The steps necessary to increase the current output of this Marx generator design to the meg-ampere region or higher are specified.

  5. An absence of ex-companion stars in the type Ia supernova remnant SNR 0509-67.5.

    PubMed

    Schaefer, Bradley E; Pagnotta, Ashley

    2012-01-12

    A type Ia supernova is thought to begin with the explosion of a white dwarf star. The explosion could be triggered by the merger of two white dwarfs (a 'double-degenerate' origin), or by mass transfer from a companion star (the 'single-degenerate' path). The identity of the progenitor is still controversial; for example, a recent argument against the single-degenerate origin has been widely rejected. One way to distinguish between the double- and single-degenerate progenitors is to look at the centre of a known type Ia supernova remnant to see whether any former companion star is present. A likely ex-companion star for the progenitor of the supernova observed by Tycho Brahe has been identified, but that claim is still controversial. Here we report that the central region of the supernova remnant SNR 0509-67.5 (the site of a type Ia supernova 400 ± 50 years ago, based on its light echo) in the Large Magellanic Cloud contains no ex-companion star to a visual magnitude limit of 26.9 (an absolute magnitude of M(V) = +8.4) within a region of radius 1.43 arcseconds. (This corresponds to the 3σ maximum distance to which a companion could have been 'kicked' by the explosion.) This lack of any ex-companion star to deep limits rules out all published single-degenerate models for this supernova. The only remaining possibility is that the progenitor of this particular type Ia supernova was a double-degenerate system. PMID:22237107

  6. An absence of ex-companion stars in the type Ia supernova remnant SNR 0509-67.5

    NASA Astrophysics Data System (ADS)

    Schaefer, Bradley E.; Pagnotta, Ashley

    2012-01-01

    A type Ia supernova is thought to begin with the explosion of a white dwarf star. The explosion could be triggered by the merger of two white dwarfs (a `double-degenerate' origin), or by mass transfer from a companion star (the `single-degenerate' path). The identity of the progenitor is still controversial; for example, a recent argument against the single-degenerate origin has been widely rejected. One way to distinguish between the double- and single-degenerate progenitors is to look at the centre of a known type Ia supernova remnant to see whether any former companion star is present. A likely ex-companion star for the progenitor of the supernova observed by Tycho Brahe has been identified, but that claim is still controversial. Here we report that the central region of the supernova remnant SNR 0509-67.5 (the site of a type Ia supernova 400 +/- 50 years ago, based on its light echo) in the Large Magellanic Cloud contains no ex-companion star to a visual magnitude limit of 26.9 (an absolute magnitude of MV = +8.4) within a region of radius 1.43 arcseconds. (This corresponds to the 3σ maximum distance to which a companion could have been `kicked' by the explosion.) This lack of any ex-companion star to deep limits rules out all published single-degenerate models for this supernova. The only remaining possibility is that the progenitor of this particular type Ia supernova was a double-degenerate system.

  7. An absence of ex-companion stars in the type Ia supernova remnant SNR 0509-67.5.

    PubMed

    Schaefer, Bradley E; Pagnotta, Ashley

    2012-01-11

    A type Ia supernova is thought to begin with the explosion of a white dwarf star. The explosion could be triggered by the merger of two white dwarfs (a 'double-degenerate' origin), or by mass transfer from a companion star (the 'single-degenerate' path). The identity of the progenitor is still controversial; for example, a recent argument against the single-degenerate origin has been widely rejected. One way to distinguish between the double- and single-degenerate progenitors is to look at the centre of a known type Ia supernova remnant to see whether any former companion star is present. A likely ex-companion star for the progenitor of the supernova observed by Tycho Brahe has been identified, but that claim is still controversial. Here we report that the central region of the supernova remnant SNR 0509-67.5 (the site of a type Ia supernova 400 ± 50 years ago, based on its light echo) in the Large Magellanic Cloud contains no ex-companion star to a visual magnitude limit of 26.9 (an absolute magnitude of M(V) = +8.4) within a region of radius 1.43 arcseconds. (This corresponds to the 3σ maximum distance to which a companion could have been 'kicked' by the explosion.) This lack of any ex-companion star to deep limits rules out all published single-degenerate models for this supernova. The only remaining possibility is that the progenitor of this particular type Ia supernova was a double-degenerate system.

  8. AIDS and racism in America.

    PubMed

    Hutchinson, J

    1992-02-01

    Institutionalized racism affects general health care as well as acquired immunodeficiency syndrome (AIDS) health intervention and services in minority communities. The overrepresentation of minorities in various disease categories, including AIDS, is partially related to racism. The national response to the AIDS epidemic in minority communities has been slow, showing an insensitivity to ethnic diversity in prevention efforts and AIDS health services.

  9. The First Aid Training Picture.

    ERIC Educational Resources Information Center

    Moore, Ian

    2000-01-01

    Discusses the history of first aid training provisions in the United Kingdom with respect to the outdoor industry, what to look for in a first aid training provider, an experiential model of first aid training, and the current National Governing Body requirements for first aid training for various types of coaches and instructors. (TD)

  10. Answering Your Questions about AIDS.

    ERIC Educational Resources Information Center

    Kalichman, Seth C.

    This book focuses on AIDS education and answers 350 commonly asked questions about Human Immunodeficiency Virus (HIV) and Acquired Immune Deficiency Syndrome (AIDS) taken from questions addressed to two major urban AIDS hotlines (Milwaukee, Wisconsin, and Houston, Texas). Chapter 1, "HIV - The Virus That Causes AIDS," discusses: the HIV virus; the…

  11. Sensory Aids for the Blind.

    ERIC Educational Resources Information Center

    National Academy of Sciences - National Research Council, Washington, DC. Committee on Prosthetics Research and Development.

    The problems of providing sensory aids for the blind are presented and a report on the present status of aids discusses direct translation and recognition reading machines as well as mobility aids. Aspects of required research considered are the following: assessment of needs; vision, audition, taction, and multimodal communication; reading aids,…

  12. Water resources and environmental input-output analysis and its key study issues: a review

    NASA Astrophysics Data System (ADS)

    YANG, Z.; Xu, X.

    2013-12-01

    Used to study the material and energy flow in socioeconomic system, Input-Output Analysis(IOA) had been an effective analysis tool since its appearance. The research fields of Input-Output Analysis were increasingly expanded and studied in depth with the development of fundamental theory. In this paper, starting with introduction of theory development, the water resources input-output analysis and environmental input-output analysis had been specifically reviewed, and two key study issues mentioned as well. Input-Occupancy-Output Analysis and Grey Input-Output Analysis whose proposal and development were introduced firstly could be regard as the effective complements of traditional IOA theory. Because of the hypotheses of homogeneity, stability and proportionality, Input-Occupancy-Output Analysis and Grey Input-Output Analysis always had been restricted in practical application inevitably. In the applied study aspect, with investigation of abundant literatures, research of water resources input-output analysis and environmental input-output analysis had been comprehensively reviewed and analyzed. The regional water resources flow between different economic sectors had been systematically analyzed and stated, and several types of environmental input-output analysis models combined with other effective analysis tools concluded. In two perspectives in terms of external and inland aspect, the development of water resources and environmental input-output analysis model had been explained, and several typical study cases in recent years listed respectively. By the aid of sufficient literature analysis, the internal development tendency and study hotspot had also been summarized. In recent years, Chinese literatures reporting water resources consumption analysis and virtue water study had occupied a large share. Water resources consumption analysis had always been the emphasis of inland water resources IOA. Virtue water study had been considered as the new hotspot of

  13. Coupling output of multichannel high power microwaves

    SciTech Connect

    Li Guolin; Shu Ting; Yuan Chengwei; Zhang Jun; Yang Jianhua; Jin Zhenxing; Yin Yi; Wu Dapeng; Zhu Jun; Ren Heming; Yang Jie

    2010-12-15

    The coupling output of multichannel high power microwaves is a promising technique for the development of high power microwave technologies, as it can enhance the output capacities of presently studied devices. According to the investigations on the spatial filtering method and waveguide filtering method, the hybrid filtering method is proposed for the coupling output of multichannel high power microwaves. As an example, a specific structure is designed for the coupling output of S/X/X band three-channel high power microwaves and investigated with the hybrid filtering method. In the experiments, a pulse of 4 GW X band beat waves and a pulse of 1.8 GW S band microwave are obtained.

  14. Scaling of global input-output networks

    NASA Astrophysics Data System (ADS)

    Liang, Sai; Qi, Zhengling; Qu, Shen; Zhu, Ji; Chiu, Anthony S. F.; Jia, Xiaoping; Xu, Ming

    2016-06-01

    Examining scaling patterns of networks can help understand how structural features relate to the behavior of the networks. Input-output networks consist of industries as nodes and inter-industrial exchanges of products as links. Previous studies consider limited measures for node strengths and link weights, and also ignore the impact of dataset choice. We consider a comprehensive set of indicators in this study that are important in economic analysis, and also examine the impact of dataset choice, by studying input-output networks in individual countries and the entire world. Results show that Burr, Log-Logistic, Log-normal, and Weibull distributions can better describe scaling patterns of global input-output networks. We also find that dataset choice has limited impacts on the observed scaling patterns. Our findings can help examine the quality of economic statistics, estimate missing data in economic statistics, and identify key nodes and links in input-output networks to support economic policymaking.

  15. Output Measures and Library Space Planning.

    ERIC Educational Resources Information Center

    Lushington, Nolan

    1987-01-01

    Draws some initial connections between library performance measures and library space planning and collection management. Output measure surveys are suggested for establishing hierarchies of use and appropriate design of environments for housing the collection. Four references are listed. (MES)

  16. Memory-based parallel data output controller

    NASA Technical Reports Server (NTRS)

    Stattel, R. J.; Niswander, J. K. (Inventor)

    1984-01-01

    A memory-based parallel data output controller employs associative memories and memory mapping to decommutate multiple channels of telemetry data. The output controller contains a random access memory (RAM) which has at least as many address locations as there are channels. A word counter addresses the RAM which provides as it outputs an encoded peripheral device number and a MSB/LSB-first flag. The encoded device number and a bit counter address a second RAM which contains START and STOP flags to pick out the required bits from the specified word number. The LSB/MSB, START and STOP flags, along with the serial input digital data go to a control block which selectively fills a shift register used to drive the parallel data output bus.

  17. Coupling output of multichannel high power microwaves

    NASA Astrophysics Data System (ADS)

    Li, Guolin; Shu, Ting; Yuan, Chengwei; Zhang, Jun; Yang, Jianhua; Jin, Zhenxing; Yin, Yi; Wu, Dapeng; Zhu, Jun; Ren, Heming; Yang, Jie

    2010-12-01

    The coupling output of multichannel high power microwaves is a promising technique for the development of high power microwave technologies, as it can enhance the output capacities of presently studied devices. According to the investigations on the spatial filtering method and waveguide filtering method, the hybrid filtering method is proposed for the coupling output of multichannel high power microwaves. As an example, a specific structure is designed for the coupling output of S/X/X band three-channel high power microwaves and investigated with the hybrid filtering method. In the experiments, a pulse of 4 GW X band beat waves and a pulse of 1.8 GW S band microwave are obtained.

  18. Detection of X-Ray Line Emission from the Shell of SNR B0540-69.3 with XMM-Newton RGS

    NASA Technical Reports Server (NTRS)

    vanderHeyden, K. J.; Cottam, J.; Paerels, F.; Kaastra, J. S.; Branduardi-Raymont, G.

    2000-01-01

    We present X-ray observations of PSR 0540-69.3 with the XMM-Newton observatory. The spectra obtained with the Reflection Grating Spectrometer reveal, for the first time, emission from ionized species of O, Ne and Fe originating from the SNR shell. Analysis of the emission line spectrum allows us to derive estimates of the temperature, ionization timescale, abundances, location, and velocity of the emitting gas.

  19. Factors affecting the use and perceived benefit of ITE and BTE hearing aids.

    PubMed

    Baumfield, A; Dillon, H

    2001-08-01

    The aim of the present study was to investigate factors that might affect hearing aid use, satisfaction and perceived benefit. A further aim was to look at which variables affect the choice of hearing aid, in particular, an in-the-ear (ITE) versus a behind-the-ear (BTE) device. Twenty-nine elderly hearing-impaired people with a mild-to-moderate hearing loss were fitted with both an ITE and a BTE hearing aid with similar electroacoustic performance. Both hearing aids were linear with output compression limiting and were fitted in a randomized order. After wearing each device for a six-week period, subj ets were asked to select the hearing aid they preferred. Variables significantly related to hearing aid choice, use and perceived benefit included ease of management, accuracy with which the NAL-R insertion gain target was achieved, earmould comfort and the type of hearing aid the client preferred initially.

  20. Anomalous light output from lightning dart leaders

    NASA Technical Reports Server (NTRS)

    Guo, C.; Krider, E. P.

    1985-01-01

    About 5 percent of the multiple-stroke cloud-to-ground lightning discharges recorded at the NASA Kennedy Space Center during the summer of 1981 contained dart leaders that produced an unusually large light output. An analysis of these cases indicates that the average peak light output per unit length in the leader may be comparable to or even exceed that of the return stroke that follows.

  1. Extensive air showers generated by gamma-quanta from Geminga and Tycho's SNR at energy range 1 30 TeV

    NASA Astrophysics Data System (ADS)

    Sinitsyna, V. G.; Arsov, T. P.; Alaverdian, A. Y.; Borisov, S. S.; Musin, F. I.; Nikolsky, S. I.; Sinitsyna, V. Y.; Platonov, G. F.

    2006-01-01

    The gamma-quantum emitting objects in our Galaxy are supernova remnants and binary. The observed results of gamma-quantum sources Tycho Brahe and Geminga by the SHALON gamma-telescope are presented. The integral spectra of events from the source - k and background events, observing simultaneously with source's events - k, and the source image are presented. The energy spectra of Tycho's SNR and Geminga supernova remnant F(E>0.8TeV)˜E are harder than the Crab Nebula spectrum. Tycho's SNR has long been considered as a candidate cosmic ray source in Northern Hemisphere. A non-linear kinetic model of cosmic ray acceleration in supernova remnants was used for Tycho's SNR. The expected π°-decay gamma-quanta flux F˜Eγ-1 extends up to ˜30TeV, whereas the Inverse Compton gamma-ray flux has a cut-off above a few TeV. So, the detection of gamma-rays at energies of ˜10-30TeV by SHALON is evidence for hadron origin.

  2. Unstable resonator with reduced output coupling.

    PubMed

    Pargmann, Carsten; Hall, Thomas; Duschek, Frank; Grünewald, Karin Maria; Handke, Jürgen

    2012-06-20

    The properties of a laser beam coupled out of a standard unstable laser resonator are heavily dependent on the chosen resonator magnification. A higher magnification results in a higher output coupling and a better beam quality. But in some configurations, an unstable resonator with a low output coupling in combination with a good beam quality is desirable. In order to reduce the output coupling for a particular resonator, magnification fractions of the outcoupled radiation are reflected back into the cavity. In the confocal case, the output mirror consists of a spherical inner section with a high reflectivity and a flat outer section with a partial reflectivity coating. With the application of the unstable resonator with reduced output coupling (URROC), magnification and output coupling can be adjusted independently from each other and it is possible to get a good beam quality and a high power extraction for lasers with a large low gain medium. The feasibility of this resonator design is examined numerically and experimentally with the help of a chemical oxygen iodine laser. PMID:22722301

  3. Input/output system for multiprocessors

    SciTech Connect

    Bernick, D.L.; Chan, K.K.; Chan, W.M.; Dan, Y.F.; Hoang, D.M.; Hussain, Z.; Iswandhi, G.I.; Korpi, J.E.; Sanner, M.W.; Zwangerman, J.A.

    1989-04-11

    A device controller is described, comprising: a first port-input/output controller coupled to a first input/output channel bus; and a second port-input/output controlled coupled to a second input/output channel bus; each of the first and second port-input/output controllers having: a first ownership latch means for granting shared ownership of the device controller to a first host processor to provide a first data path on a first I/O channel through the first port I/O controller between the first host processor and any peripheral, and at least a second ownership latch means operative independently of the first ownership latch means for granting shared ownership of the device controller to a second host processor independently of the first port input/output controller to provide a second data path on a second I/O channel through the second port I/O controller between the second host processor and any peripheral devices coupled to the device controller.

  4. Gay youth and AIDS.

    PubMed

    Feldman, D A

    1989-01-01

    Gay male teenagers face considerable adversity during their "coming out" process due to the AIDS epidemic. They must decide whether to be tested for HIV-1 infection, whether to postpone sexual activity, how to select a partner, and which kinds of sexual practices to engage in. Gay youth often make such decisions based upon misinformation and faulty premises. This paper reviews what is known about gay youth and AIDS, and assesses their possible risk for HIV-1 infection. It is recommended that school and community-based health education programs be developed to teach gay and bisexual youth about safe sex. Moreover, research is needed into sociocultural variations among gay youth in order to develop appropriate and effective intervention strategies for AIDS risk reduction in this diverse population.

  5. Recapture training aid.

    SciTech Connect

    Pacheco, James Edward

    2004-08-01

    The breacher's training aid described in this report was designed to simulate features of magazine and steel-plate doors. The training aid enables breachers to practice using their breaching tools on components that they may encounter when attempting to enter a facility. Two types of fixtures were designed and built: (1) a large fixture incorporates simulated hinges, hasps, lock shrouds, and pins, and (2) a small fixture simulates the cross section of magazine and steel-plate doors. The small fixture consists of steel plates on either side of a structural member, such as an I-beam. The report contains detailed descriptions and photographs of the training aids, assembly instructions, and drawings.

  6. Scaffolding Strategies during Repeated Storybook Reading: An Extension Using a Voice Output Communication Aid

    ERIC Educational Resources Information Center

    Bellon-Harn, Monica L.; Harn, William E.

    2008-01-01

    Adult scaffolding during repeated storybook reading was developed for children who use speech as their primary expressive modality, but through the use of augmentative and alternative communication, it has been extended to children who do not have functional, intelligible speech. Scaffolding strategies during repeated storybook reading and during…

  7. A constitution for AIDS.

    PubMed

    Koshy, L M

    1996-01-15

    The Indian Health Organization projected the number of deaths per day due to AIDS by the year 2000 at 10,000. An interdisciplinary international conference was held in New Delhi to draft an international law governing the issues related to AIDS. Human freedom and public health policies are the most affected by this disease. In the absence of an international AIDS law, judicial verdicts set precedents and could have serious ramifications. A participant from the John Marshall Law School, Chicago, suggested that instead of making new laws, the existing ones from the colonial past should be repealed. This includes Section 377 of the Indian Penal Code, which provides criminal sanctions against those who indulge in unnatural relations with man, woman, or animal. Penalizing homosexuality will only perpetuate clandestine relations and spread the virus into their families. Another participant seconded this motion stating that even a sex worker must be protected from abuse and indignity. The National AIDS Control Organization responded to the criticism that the government had not utilized all the World Bank funds allocated for anti-AIDS projects. The trends of the epidemic were the most important indicators not just the numbers. In Manipur and Mizoram, infection was almost entirely due to injecting drug use. The Saheli project undertaken in the red-light areas of Bombay encompassed brothel owners and prostitutes, which could be replicated in other areas. Because existing government policies were focusing on prevention, there was no protection of an HIV-infected individual's privacy, one participant from Madras stated. The confidentiality issue was also echoed by a US participant. The New Delhi Declaration and Action Plan on HIV/AIDS was also discussed. It forbids discrimination in employment, education, housing, health care, social security, travel, and marital and reproductive rights. Providing sterile needles and ensuring the safety of the blood supply were other concerns

  8. AIDS--legal issues.

    PubMed

    Kirby, M

    1988-01-01

    Legal issues worldwide prompted by the AIDS epidemic are discussed, in a general way, since legal systems vary widely in different countries and localities. WHO publishes a tabulation of legal instruments dealing with AIDS and HIV infection. Criminal laws intended to protect people from harm from HIV infection have been enacted, such as a penalty for unprotected sexual intercourse by infected persons, in some Australian states. Knowing spread of HIV already amounts to a crime in many systems. The U.S. Supreme Court has already ruled that states do not violate the constitution for punishing homosexuals for consensual sodomy, nor the Army for discharging homosexuals. Quarantine law is a civil matter, but may provide penalties stricter than criminal penalties, without as much protection. No quarantines against AIDS have been enacted, although some countries require screening of immigrants. Legal issues regarding screening, liability of suppliers of blood products, and tracing of sexual partners are much discussed. Stigmatization of minority and alienated groups such as homosexuals, prostitutes, migrants, drug users and prisoners is a tricky legal problem. The apparent failure of the criminalization of drug users and how to contain the spread of AIDS into the drug free population may prompt drastic new solutions. Other legal issues drawing attention include regulation of health insurance, changes in family law, pre-marriage HIV tests, screening for HIV ostensibly to detect HIV-associated dementia, liability protection for developers and testers of vaccines, and euthanasia and the treatment of the deceased. The legal system tends to lag behind medicine. In the case of AIDS, it cannot afford to delay, therefore effective legal strategies will include effective media presentation of AIDS information to the general public; ready and cheap supply of condoms; and a new approach to illegal drugs.

  9. Software aids plant management

    SciTech Connect

    Winiger, T. )

    1992-11-01

    This paper reports that for most utilities, computer aided engineering (CAE) systems are currently used for operating plant support rather than new plant design particularly for nuclear plant maintenance. For nuclear power generating utilities, switching to a modern, integrated CAE information system can offer significant benefits. During the last decade, however, most engineering automation in the power generation industry focused on computer-aided drafting and stand-alone engineering applications. An integrated CAE system can be a useful too, assisting engineers with many engineering and operational activities. It also can be used to manage the massive amount of information created throughout the life of a plant.

  10. Good Teaching Aids.

    ERIC Educational Resources Information Center

    National Audubon Society, New York, NY.

    This set of teaching aids consists of 14 Audubon Nature Bulletins with these titles: Schoolyard Laboratories, How to Lead a Field Trip, Natural Resources in the City, Mysteries of Bird Migration, Rock Stories and How to Read Them, The Ground Water Table, The Terrarium, Some Adventures With Wild Plants Outdoors and Indoors, Plant Propagation in the…

  11. AIDS Researcher Gives Retrospective

    ERIC Educational Resources Information Center

    Hawkins, B. Denise

    2011-01-01

    Nearly 30 years ago, renowned immunologist James E.K. Hildreth, M.D., Ph.D., was compelled to start researching the virus that causes AIDS. He marveled at its enigma and was pressed into action by its ability to cut lives short and devastate communities. The disease set him on a course of medical inquiry that has included biomedical breakthroughs…

  12. More than First Aid

    ERIC Educational Resources Information Center

    Schoessler, Sally

    2011-01-01

    The school nurse is an important member of the school team since school health services keep students in school, in the classroom, and ready to learn. Although school nurses are often seen as the people who deliver first aid at school, their role is much deeper and has such breadth that only a registered, professional nurse has the skill set to…

  13. Living with AIDs.

    ERIC Educational Resources Information Center

    Graubard, Stephen R., Ed.

    1989-01-01

    Because events move swiftly in the contemporary world, it is easy to forget that acquired immune deficiency syndrome (AIDS) is a phenomenon of the 1980s. It is generally agreed that this is only the very beginning of a scientific investigation that will go on well into the 21st century. This issue attempts to provide some of the basic information…

  14. First Aid Instruction Course.

    ERIC Educational Resources Information Center

    Bureau of Mines (Dept. of Interior), Washington, DC.

    Prepared by the Department of the Interior, this teaching guide is for the instructors' use in teaching a first aid course. Six fundamental areas include: (1) Artificial Respiration, (2) Control of Bleeding, (3) Physical Shock, (4) Open Wounds, Closed Wounds, and Burns, (5) Fractures and Dislocations, and (6) Transportation. A complete…

  15. Kool-Aid Chromatography

    ERIC Educational Resources Information Center

    Jenkins, Christie L.

    1986-01-01

    Offers guidelines and suggests activities that can introduce middle school students to the process and principles of chromatography in an inexpensive and safe manner. Proposes that experiences with Kool-aid and food coloring chromatography can provide insights into how scientists think, work, and communicate. (ML)

  16. First Aid Challenge

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2011-01-01

    This article describes a challenge wherein students will be asked to design a portable first aid kit that is normally carried in a recreational vehicle (RV), but can also be hand-carried or backpacked off road for distances of approximately 1-2 miles. This can be a very practical challenge for the students because it touches everyone. Everybody…

  17. Child Care Aide.

    ERIC Educational Resources Information Center

    Texas Tech. Univ., Lubbock. School of Home Economics.

    This course of study for the child care aide is one of a series available for use by teacher-coordinators and students in Grade 11 and 12 home economics cooperative education programs. Based on job analysis interviews with child care center personnel, the course was prepared by teacher and Instructional Materials Center staff, field-tested, and…

  18. Coil Welding Aid

    NASA Technical Reports Server (NTRS)

    Wiesenbach, W. T.; Clark, M. C.

    1983-01-01

    Positioner holds coil inside cylinder during tack welding. Welding aid spaces turns of coil inside cylinder and applies contact pressure while coil is tack-welded to cylinder. Device facilitates fabrication of heat exchangers and other structures by eliminating hand-positioning and clamping of individual coil turns.

  19. Parent Hearing Aid Experiences

    ERIC Educational Resources Information Center

    Munoz, Karen; Roberts, Mallory; Mullings, Day; Harward, Richard

    2012-01-01

    This study addresses parent experiences in obtaining and managing hearing aids for their young child. The purpose was to identify challenges parents encounter to determine what state agencies can do to improve parent access to amplification. Data were collected July through September of 2010; 40 parents of children ages birth to 3 years old…

  20. Circulation Aide Training Manual.

    ERIC Educational Resources Information Center

    Bergeson, Alan O.

    This training manual provides instruction on shelving and other duties for student assistants in the learning resources center at the College of Dupage, located in Illinois. It is noted that prospective student circulation aides are required to read the manual and pass a written test on policies and procedures before they are allowed to shelve…

  1. AIDS: The Second Decade.

    ERIC Educational Resources Information Center

    Miller, Heather G., Ed.; And Others

    This report reviews the course of the Acquired Immune Deficiency Syndrome (AIDS) epidemic and its current status, examining changing patterns of sexual behavior and intravenous drug use, the distribution of cases of human immunodeficiency virus (HIV) infection, and the results of intervention efforts under way. It also discusses prevention…

  2. Computer Aided Art Major.

    ERIC Educational Resources Information Center

    Gibson, Jim

    The Computer Aided Art program offered at Northern State State University (Aberdeen, South Dakota), is coordinated with the traditional art major. The program is designed to familiarize students with a wide range of art-related computer hardware and software and their applications and to prepare students for problem-solving with unfamiliar…

  3. The War against AIDS.

    ERIC Educational Resources Information Center

    Bowles, L. Thompson

    1987-01-01

    Efforts of the U.S. Department of Health and Human Services to combat AIDS are reported. Health implications of the viral disease are summarized, along with economic costs, research achievements, the importance of education, and appropriate and workable solutions. (LB)

  4. Machine-Aided Indexing.

    ERIC Educational Resources Information Center

    Jacobs, Charles R.

    Progress is reported at the 1,000,000 word level on the development of a partial syntatic analysis technique for indexing text. A new indexing subroutine for hyphens is provided. New grammars written and programmed for Machine Aided Indexing (MAI) are discussed. (ED 069 290 is a related document) (Author)

  5. Instructional Aide Program.

    ERIC Educational Resources Information Center

    Thomson, Henry

    The Instructional Aide Program (Shoreline Community College, Seattle, Washington) is a flexible curriculum designed to prepare students to meet the paraprofessional manpower needs of several kinds of institution. It was prepared after consultation with representatives of the schools, the YMCA, and the country park system. Other agencies still to…

  6. Range Scheduling Aid (RSA)

    NASA Technical Reports Server (NTRS)

    Logan, J. R.; Pulvermacher, M. K.

    1991-01-01

    Range Scheduling Aid (RSA) is presented in the form of the viewgraphs. The following subject areas are covered: satellite control network; current and new approaches to range scheduling; MITRE tasking; RSA features; RSA display; constraint based analytic capability; RSA architecture; and RSA benefits.

  7. First Aid: Chickenpox

    MedlinePlus

    ... Palsy: Shannon's Story" 5 Things to Know About Zika & Pregnancy First Aid: Chickenpox ... Chickenpox (varicella) is an illness that has become much less common in the U.S. due to the chickenpox vaccine . The infection and rash will go away without ...

  8. Newspaper Lesson Aids.

    ERIC Educational Resources Information Center

    Communication: Journalism Education Today (C:JET), 1986

    1986-01-01

    Provides photocopy-ready lesson aids on story ideas, interviewing, inverted pyramid writing style, newswriting, sports/scavenger hunt, finding feature material, identifying feature leads, feature lead selection, evaluating feature leads, compiling survey material, cutlines, headlines, paste-up rules, advertising, final semester project, newspaper…

  9. Street Youth & AIDS.

    ERIC Educational Resources Information Center

    Radford, Joyce L.; And Others

    Interviews were conducted with 712 Canadian street youth (ages 15-20 years) to assess their knowledge, attitudes, and behaviors with regard to Acquired Immune Deficiency Syndrome (AIDS) and other sexually transmitted diseases (STDs). Youth were interviewed in 10 cities across Canada on the basis of 5 street culture lifestyles: prostitution, drug…

  10. Response requirements as constraints on output.

    PubMed

    Zeiler, M D; Buchman, I B

    1979-07-01

    Two experiments studied how added response requirements affected fixed-interval schedule performance. Experiment 1 involved tandem fixed-interval fixed-ratio schedules, and Experiment 2 studied conjunctive fixed-interval fixed-ratio schedules. In both, pigeons' output, defined as overall response rate or as responses during the interval, first increased and then decreased as the ratio was raised. With small ratio requirements, the frequency of reinforcement in time either did not change or decreased slightly. With progressively larger ratios, reinforcement frequency decreased consistently. Alternative explanations were discussed. The first, a reinforcement theory account, was that response strength is an increasing monotonic function of both the response requirement and reinforcement frequency, and the bitonic output function represents interacting effects. Increases in the response requirement accompanied by small changes in reinforcement frequency enhance output, but further increases result in large enough decrements in reinforcement frequency so that output is lowered. The second explanation does not view reinforcement as a basic process but, instead, derives from concepts of economics and conservation. Organisms allocate their behavior among alternatives so as to maximize value, where value is a function of the responses that can occur in a given situation under the set of restrictions imposed by particular schedules. One form of this theory explicitly predicts that output is a bitonic function of ratio requirements in simple ratio schedules. However, it was not clear that this model could explain the present effects involving joint ratio and interval schedule restrictions.

  11. Linear summation of cat motor cortex outputs.

    PubMed

    Ethier, Christian; Brizzi, Laurent; Darling, Warren G; Capaday, Charles

    2006-05-17

    Recruitment of movement-related muscle synergies involves the functional linking of motor cortical points. We asked how the outputs of two simultaneously stimulated motor cortical points would interact. To this end, experiments were done in ketamine-anesthetized cats. When prolonged (e.g., 500 ms) trains of intracortical microstimulation were applied in the primary motor cortex, stimulus currents as low as 10-20 microA evoked coordinated movements of the contralateral forelimb. Paw kinematics in three dimensions and the electromyographic (EMG) activity of eight muscles were simultaneously recorded. We show that the EMG outputs of two cortical points simultaneously stimulated are additive. The movements were represented as displacement vectors pointing from initial to final paw position. The displacement vectors resulting from simultaneous stimulation of two cortical points pointed in nearly the same direction as the algebraic resultant vector. Linear summation of outputs was also found when inhibition at one of the cortical points was reduced by GABAA receptor antagonists. A simple principle emerges from these results. Notwithstanding the underlying complex neuronal circuitry, motor cortex outputs combine nearly linearly in terms of movement direction and muscle activation patterns. Importantly, simultaneous activation does not change the nature of the output at each point. An additional implication is that not all possible movements need be explicitly represented in the motor cortex; a large number of different movements may be synthesized from a smaller repertoire.

  12. Visual Speech-Training Aid for the Deaf

    NASA Technical Reports Server (NTRS)

    Miller, Robert J.

    1987-01-01

    Teaching deaf to speak aided by electronic system provides striking colored, pictorial representation of sound; energy at different frequencies as function of time. Other modalities, such as nasality, intra-oral pressure, and lip-muscle contraction, pictorialized simultaneously. Use of standard components, including personal microcomputer, helps reduce cost below prior voice-training systems. Speech-training system, microphone output separated by filters into narrow frequency bands, changed into digital signals, formatted by computer, and displayed on television screen. Output from other sensors displayed simultaneously or screen split to allow sound produced by student to be compared with that of teacher.

  13. Screening for AIDS.

    PubMed

    1985-03-29

    Tests to detect serum antibody to human T-lymphotropic virus type III (HTLV-III), based on an enzyme-linked immunosorbent assay (ELISA) that uses whole disrupted HTLV-III virus antigens, are now commercially available in the US. Recent surveys of groups at high risk for acquired immunodeficiency syndrome (AIDS) have found that 22-65% of homosexual men, 87% of active intravenous drug users, 56-72% of hemophiliacs, and 35% of women who were sexual partners of men with AIDS have had postitive ELISA tests compared with fewer than 1% of those with no known risk factors. A positive ELISA test could be due to subclinical infection, immunity, or cross-reactivity with other viral antigens. Laboratory error can also produce false positive results. Thus, it is recommended that the ELISA test be repeated at least once on all seropositive specimens before the result is reported to the patient. The western blot test appears to be more specific and less sensitive than the ELISA. Studies of asymptomatic seropositive homosexual men followed for 2-5 years have found that over 50% remain asymptomatic, 5-19% develop full blown AIDS, and 25% develop signs suggestive of the AIDS-related complex. Asymptomatic patients with positive ELISA tests should be made aware of early signs and symptoms of AIDS. Other data suggest that seropositive patients have the HTLV-III virus in their blood, semen, and/or saliva and can transmit the infection. Precautions to prevent transmission, such as the use of condoms, should be taken by such patients. Physicians should be sensitive to the fear and anxiety that a positive ELISA test will create.

  14. AIDS: there's hope.

    PubMed

    1993-06-01

    In 1993, 10 years after realizing that AIDS posed a threat to the future of mankind, social mobilization will improve the odds against AIDS. The objective is to create awareness about the virus, and to affect positive behavioral change through advocacy, communication, and grass-roots actions. The first goal is to change the societal attitude about the status of youth and women in order to understand that gender inequality fuels the pandemic. They are the most vulnerable groups, therefore their economic and social power must be improved. The Convention on the Rights of the Child and the Convention on the Elimination of All Forms of Discrimination against Women constitute a platform for broader action by governmental, nongovernmental, and religious institutions. In addition, these organizations need strong allies in society: 1) the media, which can communicate the importance of youth, women, and attitudes in the epidemic; 2) religious leaders, who can be powerful sources of advocacy for change in attitudes as well as support and care for AIDS-affected individuals and families; 3) policy makers, who can be crucial in changing existing policies and altering the allocation of government resources to youth and women; 4) human rights organizations, which play an important role in promoting the concept of health as a human right and for enhancing the understanding of AIDS in the context of discrimination and poverty; 5) the private sector, including commerce and industry, which can promote changes in attitude within the work force and AIDS prevention initiatives; and 6) parent-teacher groups and models for youth, who can educate them about socially acceptable and unacceptable behavior and can empower them to make responsible behavior choices.

  15. PV output smoothing with energy storage.

    SciTech Connect

    Ellis, Abraham; Schoenwald, David Alan

    2012-03-01

    This report describes an algorithm, implemented in Matlab/Simulink, designed to reduce the variability of photovoltaic (PV) power output by using a battery. The purpose of the battery is to add power to the PV output (or subtract) to smooth out the high frequency components of the PV power that that occur during periods with transient cloud shadows on the PV array. The control system is challenged with the task of reducing short-term PV output variability while avoiding overworking the battery both in terms of capacity and ramp capability. The algorithm proposed by Sandia is purposely very simple to facilitate implementation in a real-time controller. The control structure has two additional inputs to which the battery can respond. For example, the battery could respond to PV variability, load variability or area control error (ACE) or a combination of the three.

  16. Formation of output in copper vapor lasers.

    PubMed

    Coutts, D W; Brown, D J

    1995-03-20

    Detailed mechanisms that control the formation of output from copper vapor laser (CVL) oscillators are investigated. Measurements of the spatial and temporal evolution of gain in a CVL amplifier and a CVL oscillator show that a short period of high gain that occurs at the beginning of the inversion period is the dominant feature. This leads to the formation of a burst of amplified spontaneous emission (ASE), whose subsequent propagation and amplification leads to all observable CVL output. The spatial characteristics of this initial burst of ASE are shown to be strongly dependent on the operating conditions of the laser. The implications of this description of CVL output for the design of unstable resonators and oscillator-amplifier systems is discussed. PMID:21037687

  17. William Harvey, Peter Lauremberg and cardiac output.

    PubMed

    Teichmann, G

    1992-11-01

    In 1636, the Rostock professor of medicine and the art of poetry, Peter Lauremberg (1585-1639), was one of the earliest to mention circulation which had been discovered by William Harvey and documented in his anatomical manual. In 1628 William Harvey proved the existence of the blood circulation by calculating the "cardiac output in a half an hour (semihora)". The answer to the question why Harvey chose half an hour as the time range can be found in the way of measuring time usual at that period. The sandglasses were turned half-hourly in maritime navigation and the wheel-clocks on shore had only the hour-hand. Improved chronometry was one of the prerequisites for measuring cardiac output. The minute-hand became usual after 1700 and the second-hand later on. Taking into consideration the alterations of cardiac output made the latter one of the most important circulation parameters in diagnostics, prognostication and therapeutics.

  18. Pole placement with constant gain output feedback

    NASA Technical Reports Server (NTRS)

    Sridhar, B.; Lindorff, D. P.

    1972-01-01

    Given a linear time invariant multivariable system with m inputs and p outputs, it was shown that p closed loop poles of the system can be preassigned arbitrarily using constant gain output feedback provided (A circumflex, B circumflex) is controllable. These data show that if (A circumflex, B circumflex, C circumflex) is controllable and observable, and Rank B circumflex = m, Rank C circumflex = p, then max (m,p) poles of the system can be assigned arbitarily using constant gain output feedback. Further, it is shown that in some cases more than max (m,p) poles can be arbitrarily assigned. A least square design technique is outlined to approximate the desired pole locations when it is not possible to place all the poles.

  19. HIV/AIDS and Pediatric AIDS. The Arc Q & A.

    ERIC Educational Resources Information Center

    Kowalski, Jo Anne T.

    This fact sheet uses a question-and-answer format to summarize what is known about HIV/AIDS (Human Immunodeficiency Virus and Acquired Immune Deficiency Syndrome) and pediatric AIDS and applies this information to children in school settings. Questions and answers address the following topics: what the AIDS disease and HIV infection are; estimates…

  20. Approximations of nonlinear systems having outputs

    NASA Technical Reports Server (NTRS)

    Hunt, L. R.; Su, R.

    1985-01-01

    For a nonlinear system with output derivative x = f(x) and y = h(x), two types of linearizations about a point x(0) in state space are considered. One is the usual Taylor series approximation, and the other is defined by linearizing the appropriate Lie derivatives of the output with respect to f about x(0). The latter is called the obvservation model and appears to be quite natural for observation. It is noted that there is a coordinate system in which these two kinds of linearizations agree. In this coordinate system, a technique to construct an observer is introduced.

  1. Input/Output Subroutine Library Program

    NASA Technical Reports Server (NTRS)

    Collier, James B.

    1988-01-01

    Efficient, easy-to-use program moved easily to different computers. Purpose of NAVIO, Input/Output Subroutine Library, provides input/output package of software for FORTRAN programs that is portable, efficient, and easy to use. Implemented as hierarchy of libraries. At bottom is very small library containing only non-portable routines called "I/O Kernel." Design makes NAVIO easy to move from one computer to another, by simply changing kernel. NAVIO appropriate for software system of almost any size wherein different programs communicate through files.

  2. Synthetic Output by Simulation. An Introductory Paper.

    ERIC Educational Resources Information Center

    Mason, Thomas R.

    Simulation is the process of synthetically manipulating the variables in a model of a system for the purpose of understanding, experimenting with, and predicting the behavior of that system. Many different models are now being developed by university administrators to aid them in making decisions. Simulation models have been developed for…

  3. Women and HIV/AIDS

    MedlinePlus

    ... action on HIV/AIDS National Women and Girls HIV/AIDS Awareness Day – March 10 Programs Share your story Anonymous from Illinois says... Although I am HIV negative, I would like to share my story. ...

  4. Different Styles of Hearing Aids

    MedlinePlus

    ... aids available and offer some cosmetic and listening advantages. Photo courtesy of Phonak Click for larger image ... in place. These aids offer cosmetic and listening advantages and are used typically for adults. Photo courtesy ...

  5. Porous radiant burners having increased radiant output

    DOEpatents

    Tong, Timothy W.; Sathe, Sanjeev B.; Peck, Robert E.

    1990-01-01

    Means and methods for enhancing the output of radiant energy from a porous radiant burner by minimizing the scattering and increasing the adsorption, and thus emission of such energy by the use of randomly dispersed ceramic fibers of sub-micron diameter in the fabrication of ceramic fiber matrix burners and for use therein.

  6. On the output of acoustical sources

    NASA Technical Reports Server (NTRS)

    Levine, H.

    1979-01-01

    Contents: (1) a theoretical basis for local power calculation; (2) source radiation in the presence of a half-plane; (3) radiation from a line source near an edge at which a Kutta condition holds; (4) radiation by a point source above a plane independence boundary; and (5) power output of a point source in a uniform flow.

  7. A Large Scale Computer Terminal Output Controller.

    ERIC Educational Resources Information Center

    Tucker, Paul Thomas

    This paper describes the design and implementation of a large scale computer terminal output controller which supervises the transfer of information from a Control Data 6400 Computer to a PLATO IV data network. It discusses the cost considerations leading to the selection of educational television channels rather than telephone lines for…

  8. RAM-Based parallel-output controller

    NASA Technical Reports Server (NTRS)

    Niswander, J. K.; Stattel, R. J.

    1980-01-01

    Selected bit strings in serial-data link are extracted for processing. Controller is programmable interface between serial-data link and peripherals that accept parallel data. It can be used to drive displays, printers, plotters, digital-to-analog converters, and parallel-output ports.

  9. Multiple output timing and trigger generator

    SciTech Connect

    Wheat, Robert M.; Dale, Gregory E

    2009-01-01

    In support of the development of a multiple stage pulse modulator at the Los Alamos National Laboratory, we have developed a first generation, multiple output timing and trigger generator. Exploiting Commercial Off The Shelf (COTS) Micro Controller Units (MCU's), the timing and trigger generator provides 32 independent outputs with a timing resolution of about 500 ns. The timing and trigger generator system is comprised of two MCU boards and a single PC. One of the MCU boards performs the functions of the timing and signal generation (the timing controller) while the second MCU board accepts commands from the PC and provides the timing instructions to the timing controller. The PC provides the user interface for adjusting the on and off timing for each of the output signals. This system provides 32 output or timing signals which can be pre-programmed to be in an on or off state for each of 64 time steps. The width or duration of each of the 64 time steps is programmable from 2 {micro}s to 2.5 ms with a minimum time resolution of 500 ns. The repetition rate of the programmed pulse train is only limited by the time duration of the programmed event. This paper describes the design and function of the timing and trigger generator system and software including test results and measurements.

  10. Characterizing Detonator Output Using Dynamic Witness Plates

    NASA Astrophysics Data System (ADS)

    Murphy, Michael; Adrian, Ronald

    2009-06-01

    A sub-microsecond, time-resolved micro-particle-image velocimetry (PIV) system is developed to investigate the output of explosive detonators. Detonator output is directed into a transparent solid that serves as a dynamic witness plate and instantaneous shock and material velocities are measured in a two-dimensional plane cutting through the shock wave as it propagates through the solid. For the case of unloaded initiators (e.g. exploding bridge wires, exploding foil initiators, etc.) the witness plate serves as a surrogate for the explosive material that would normally be detonated. The velocity-field measurements quantify the velocity of the shocked material and visualize the geometry of the shocked region. Furthermore, the time-evolution of the velocity-field can be measured at intervals as small as 10 ns using the PIV system. Current experimental results of unloaded exploding bridge wire output in polydimethylsiloxane (PDMS) witness plates demonstrate 20 MHz velocity-field sampling just 300 ns after initiation of the wire. Successful application of the PIV system to full-up explosive detonator output is also demonstrated.

  11. Input-output, expandable-parity network

    NASA Technical Reports Server (NTRS)

    Mckevitt, J. F., III

    1974-01-01

    Large-scale integrated circuit generates and checks parity of four eight-bit registers. In addition, circuit will indicate by output signal whether parity error exists. Circuit can also generate or check parity of words up to 32 bits. This is done by making appropriate internal wiring connections on the large-scale integrated chip.

  12. Country living with AIDS.

    PubMed

    Kletecka, C

    1998-12-01

    The number of people with HIV in rural areas is small, but it is growing. In rural areas, AIDS organizations must deal with a fragmented client base that is spread out over a large geographic area. The logistics and costs of maintaining these services are higher per person than in urban areas. A description of what it is like to live with HIV in rural Vermont is provided. Although most people in rural Vermont seem to accept the concept of AIDS, few have known someone with the disease. Specialized medical care is difficult to obtain because only one specialty clinic and three part-time sites exist in the state of Vermont. Many who require more complex care, with better treatment options, go out of state to receive it.

  13. Pharmacotherapeutics for the AIDS Patient.

    ERIC Educational Resources Information Center

    Fife, Kenneth H.

    1991-01-01

    Anticipated shifts in the demographics of the Acquired Immune Deficiency Syndrome (AIDS) epidemic are examined, current state-of-the-art AIDS patient management is summarized, and some unique facets of drug therapy in the AIDS patient are discussed, including adverse reactions, complex drug interactions, use of investigational drugs, and…

  14. Teachers' Aides: Tasks and Concerns

    ERIC Educational Resources Information Center

    Balderson, James H.; Nixon, Mary

    1976-01-01

    Addresses three questions: (1) What tasks do aides perform? (2) Does training make a difference in the type of tasks aides perform? (3) What are the concerns of aides? (Available from the Department of Educational Administration, The University of Alberta, Edmonton, Alberta, Canada T6G 2G5; $0.50, single copy.) (Author/IRT)

  15. Manual for Student Financial Aids.

    ERIC Educational Resources Information Center

    MacDonald, Douglas S.

    This manual was designed to provide structural guidelines for financial aid program operations and administration at the Community College of Baltimore. Topics discussed include: the philosophy of student aid at an open door college; the objectives of the student financial aid office; staff development and administrative improvement; organization,…

  16. How Do People Get AIDS?

    MedlinePlus

    ... a Friend Who Cuts? How Do People Get AIDS? KidsHealth > For Teens > How Do People Get AIDS? Print A A A Text Size en español ¿Cómo contrae alguien el SIDA? AIDS stands for acquired immunodeficiency syndrome , a disease that ...

  17. Living with AIDS: Part II.

    ERIC Educational Resources Information Center

    Daedalus: Journal of the American Academy of Arts and Sciences, 1989

    1989-01-01

    A series of articles concerning various aspects of AIDS and the dilemmas it poses for U.S. society, culture, and government are presented, in this theme issue, e.g., "Introduction to the Issue" (K. Keniston); "Prospects for the Medical Control of the AIDS Epidemic" (W. Haseltine); "Social Policy: AIDS and Intravenous Drug Use" (N. Zinberg);…

  18. College Costs and Student Aid.

    ERIC Educational Resources Information Center

    Green, Kenneth C.

    The growing campus role in providing student financial aid is discussed based on data from the Cooperative Institutional Research Program, Peterson's Guide, and other sources. The campus contribution to student aid programs has grown far more than recent tuition increases. A significant portion of the financial aid burden has passed from federal…

  19. Computer aided production engineering

    SciTech Connect

    Not Available

    1986-01-01

    This book presents the following contents: CIM in avionics; computer analysis of product designs for robot assembly; a simulation decision mould for manpower forecast and its application; development of flexible manufacturing system; advances in microcomputer applications in CAD/CAM; an automated interface between CAD and process planning; CAM and computer vision; low friction pneumatic actuators for accurate robot control; robot assembly of printed circuit boards; information systems design for computer integrated manufacture; and a CAD engineering language to aid manufacture.

  20. Directional Hearing Aid

    NASA Technical Reports Server (NTRS)

    Jhabvala, M.; Lin, H. C.

    1989-01-01

    Hearing-aid device indicates visually whether sound is coming from left, right, back, or front. Device intended to assist individuals who are deaf in at least one ear and unable to discern naturally directions to sources of sound. Device promotes safety in street traffic, on loading docks, and in presence of sirens, alarms, and other warning sounds. Quadraphonic version of device built into pair of eyeglasses and binaural version built into visor.

  1. AIDS in Thailand.

    PubMed

    Ryan, M P

    1991-02-18

    The reasons for the rapid spread of AIDS in Thailand, and the impact of the unique non-governmental agency Population and Community Development Association (PDA) directed by the charismatic Dr. Mechai are described. The rapid spread of AIDS in Thailand is due to presence of all possible factors facilitating HIV transmission, a large population of injecting drug addicts, an extensive mobile domestic and tourist sex industry, and an active gay community. The number of HIV-positive persons rose from 179 in 1988 to 16,359 in 1989, and is now estimated at 100,000. 1% of the Thai population works in prostitution, and from 16% of the high-income to 72% of the low-income prostitutes are infected, with their infection rates rising 10% per month. 75% of Thai men use cheap prostitutes. While the government was ignoring the AIDS threat in the early '80s, Dr. Mechai, whose name translated as "condom," was organizing the grass-roots community-based condom distribution system PDA, said to be responsible for the fall in annual population growth from 3.4% in 1968 to 1.5% in 1990. His organization now distributes contraceptives to 16,000 villages by 12,000 volunteers. He uses booklets, cards, cassettes, slide shows, videos and appearances with condom-inflating contests and costumes to de-mystify condoms with humor. Now AIDS messages are heard in taxis, on military TV and radio, and in remote villages. Converting knowledge into practice is more difficult, requiring tactful convincing of brothel operators and finding some way to reach their clients, who exert economic control over young female prostitutes. PMID:1867668

  2. Women and AIDS.

    PubMed

    Seghal, P N

    1991-04-01

    In this article, Dr. P.N. Sehgal, former director of the National Institute of Communicable Diseases in Delhi, explains the steps that women need to take to protect themselves against AIDS and discusses some issues facing women who have already contracted the disease. Because of women's lack of status in the family and society, it is harder for them to ensure their safety. Women based at home often lack information on AIDS, and those women who are informed sometimes depend on their male partner for financial support, which means that they are forced to engage in unsafe sexual practices. Safer sexual practices can reduce the risk for women. Though varying in degree of safety, some safer practices include: monogamous relationships between uninfected partners; the use of condoms for all types of sexual intercourse; non-penetrative sex practices (hugging, kissing, masturbating); reducing the number of sexual partners; avoiding sex when either of the partners has open sores or any STD. Pregnant women should also receive information concerning AIDS, including: a baby born from an HIV-infected mother has a 20-40% of being infected; the risk of transmission is higher when the mother already shows signs of AIDS; and an infected baby may die within the first few years of life. the HIV transmission may occur prepartum or during birth itself, but the risk of transmission from breastfeeding is extremely low. Dr. Sehgal stresses the need for privacy and confidentiality when dealing with carriers of the disease or when carrying out HIV testing. Above all, the rights of HIV-infected people must be protected.

  3. AIDS in Thailand.

    PubMed

    Ryan, M P

    1991-02-18

    The reasons for the rapid spread of AIDS in Thailand, and the impact of the unique non-governmental agency Population and Community Development Association (PDA) directed by the charismatic Dr. Mechai are described. The rapid spread of AIDS in Thailand is due to presence of all possible factors facilitating HIV transmission, a large population of injecting drug addicts, an extensive mobile domestic and tourist sex industry, and an active gay community. The number of HIV-positive persons rose from 179 in 1988 to 16,359 in 1989, and is now estimated at 100,000. 1% of the Thai population works in prostitution, and from 16% of the high-income to 72% of the low-income prostitutes are infected, with their infection rates rising 10% per month. 75% of Thai men use cheap prostitutes. While the government was ignoring the AIDS threat in the early '80s, Dr. Mechai, whose name translated as "condom," was organizing the grass-roots community-based condom distribution system PDA, said to be responsible for the fall in annual population growth from 3.4% in 1968 to 1.5% in 1990. His organization now distributes contraceptives to 16,000 villages by 12,000 volunteers. He uses booklets, cards, cassettes, slide shows, videos and appearances with condom-inflating contests and costumes to de-mystify condoms with humor. Now AIDS messages are heard in taxis, on military TV and radio, and in remote villages. Converting knowledge into practice is more difficult, requiring tactful convincing of brothel operators and finding some way to reach their clients, who exert economic control over young female prostitutes.

  4. Redirecting British foreign aid.

    PubMed

    Dean, M

    1994-01-01

    Britain has longed followed a disease-control strategy for providing aid in the health sector to developing, low-income countries. Given, however, the high level of waste upon tertiary care and specialized medicine in current health programs of low-income countries as documented by the World Bank; the poor performance of existing general government hospitals and clinics; and the poor image of Third World health systems in the eyes of Western officials and government ministers, the chief health advisor of the Overseas Development Administration has called for a drastic redirection of policy toward development aid. Specifically, a shift away from a specific-disease control approach toward an overall, sweeping reform of the health sector in developing countries is urged. The level of waste needs to be reduced and more attention given to the poor. Unless such changes result, government ministers will grow increasingly reluctant to provide tangible aid to the health sectors of countries in need. The availability of such funds invested in effective, well-managed health programs will grow more critical to health in the Third World as populations shift away from communicable disease morbidity and mortality toward illnesses which are of a more noncommunicable nature such as stroke and cancer.

  5. AIDS in women: epidemiology.

    PubMed

    Willoughby, A

    1989-09-01

    Several facts concerning the distribution of AIDS in U.S. female populations are clear. This disease has made significant inroads, in a quantitative sense, into the female segment of our society as documented by AIDS surveillance data, information on pregnant women and parturients, and by screening data from the military. The impact on women in the reproductive years, on the reproductive health of these women, and on the reproductive outcome of their pregnancies is of substantial concern. Monitoring epidemiologic trends in certain groups will require clever and creative strategies like those of Hoff and colleagues. Additional data may be derived from the CDC's Family of Surveys that will examine HIV prevalence in five groups (in addition to the newborn infant survey described above): intravenous drug users, patients admitted to hospitals, sexually transmitted disease clinic patients, women's health and reproductive health clinics, and tuberculosis clinics. It is hoped that the data obtained from these studies, as well as data gathered on college students and Job Corps applicants, will contribute additional information on HIV infection in women. Monitoring the progress of the AIDS epidemic in women will be difficult. Even more difficult will be the effort to respond to the epidemic in the women it most frequently affects: the poor, minority, disenfranchised women who may be involved in illegal activities (drug use, prostitution, illegal immigration) who are not well networked into the medical and social services of our society. PMID:2776374

  6. An OH(1720 MHz) Maser and a Nonthermal Radio Source in Sgr B2(M): An SNR-Molecular Cloud Interaction Site?

    NASA Astrophysics Data System (ADS)

    Yusef-Zadeh, F.; Cotton, W.; Wardle, M.; Intema, H.

    2016-03-01

    Sgr B2 is a well-known star-forming molecular cloud complex in the Galactic center region showing evidence of high energy activity as traced by the Kα neutral Fe i line at 6.4 keV, as well as GeV and TeV γ-ray emission. Here, we present Very Large Array and GMRT observations with respective resolutions of ≈ 3\\buildrel{\\prime\\prime}\\over{.} 5× 1\\buildrel{\\prime\\prime}\\over{.} 2 and 25\\prime\\prime × 25\\prime\\prime and report the detection of an OH(1720 MHz) maser, with no accompanying OH 1665, 1667, and 1612 MHz maser emission. The maser coincides with a 150 MHz nonthermal radio source in Sgr B2(M). This rare class of OH(1720 MHz) masers or the so-called supernova remnant (SNR) masers, with no main line transitions, trace shocked gas and signal the interaction of an expanding SNR with a molecular cloud. We interpret the 150 MHz radio source as either the site of a SNR-molecular gas interaction or a wind-wind collision in a massive binary system. The interaction of the molecular cloud and the nonthermal source enhances the cosmic-ray ionization rate, allows the diffusion of cosmic rays into the cloud, and produces the variable 6.4 keV line, GeV, and TeV γ-ray emission from Sgr B2(M). The cosmic-ray electron interaction with the gas in the Galactic center can not only explain the measured high values of cosmic-ray ionization and heating rates but also contribute to nonthermal bremsstrahlung continuum emission, all of which are consistent with observations.

  7. Interstellar protons in the TeV γ-ray SNR HESS J1731-347: Possible evidence for the coexistence of hadronic and leptonic γ-rays

    SciTech Connect

    Fukuda, T.; Yoshiike, S.; Sano, H.; Torii, K.; Yamamoto, H.; Fukui, Y.; Acero, F.

    2014-06-10

    HESS J1731-347 (G353.6-0.7) is one of the TeV γ-ray supernova remnants (SNRs) that shows the shell-like morphology. We have made a new analysis of the interstellar protons toward the SNR by using both the {sup 12}CO(J = 1-0) and H I data sets. The results indicate that the TeV γ-ray shell shows significant spatial correlation with the interstellar protons at a velocity range from –90 km s{sup –1} to –75 km s{sup –1}. The total mass of the interstellar medium (ISM) protons is estimated to be 6.4 × 10{sup 4} M {sub ☉}, 25% of which is atomic gas, and the distance corresponding to the velocity range is ∼5.2 kpc, a factor of 2 larger than the previous figure, 3 kpc. We have identified the cold H I gas observed as self-absorption which shows significant correspondence with the northeastern γ-ray peak. While the good correspondence between the ISM protons and TeV γ-rays in the north of the SNR lends support to the hadronic scenario for the TeV γ-rays, the southern part of the shell shows a break in the correspondence; in particular, the southwestern rim of the SNR shell shows a significant decrease of the interstellar protons by a factor of two. We argue that this discrepancy can be explained due to leptonic γ-rays because this region coincides well with the bright shell that emits non-thermal radio continuum emission and non-thermal X-rays, suggesting that the γ-rays of HESS J1713-347 consist of both the hadronic and leptonic components. The leptonic contribution corresponds to ∼20% of the total γ-rays.

  8. Interstellar Protons in the TeV γ-Ray SNR HESS J1731-347: Possible Evidence for the Coexistence of Hadronic and Leptonic γ-Rays

    NASA Astrophysics Data System (ADS)

    Fukuda, T.; Yoshiike, S.; Sano, H.; Torii, K.; Yamamoto, H.; Acero, F.; Fukui, Y.

    2014-06-01

    HESS J1731-347 (G353.6-0.7) is one of the TeV γ-ray supernova remnants (SNRs) that shows the shell-like morphology. We have made a new analysis of the interstellar protons toward the SNR by using both the 12CO(J = 1-0) and H I data sets. The results indicate that the TeV γ-ray shell shows significant spatial correlation with the interstellar protons at a velocity range from -90 km s-1 to -75 km s-1. The total mass of the interstellar medium (ISM) protons is estimated to be 6.4 × 104 M ⊙, 25% of which is atomic gas, and the distance corresponding to the velocity range is ~5.2 kpc, a factor of 2 larger than the previous figure, 3 kpc. We have identified the cold H I gas observed as self-absorption which shows significant correspondence with the northeastern γ-ray peak. While the good correspondence between the ISM protons and TeV γ-rays in the north of the SNR lends support to the hadronic scenario for the TeV γ-rays, the southern part of the shell shows a break in the correspondence; in particular, the southwestern rim of the SNR shell shows a significant decrease of the interstellar protons by a factor of two. We argue that this discrepancy can be explained due to leptonic γ-rays because this region coincides well with the bright shell that emits non-thermal radio continuum emission and non-thermal X-rays, suggesting that the γ-rays of HESS J1713-347 consist of both the hadronic and leptonic components. The leptonic contribution corresponds to ~20% of the total γ-rays.

  9. Managing AIDS in the workplace.

    PubMed

    Esposito, M D; Myers, J E

    1993-01-01

    Because of the AIDS epidemic and the protections afforded individuals with AIDS under the Americans with Disabilities Act (ADA), employers are well advised to ensure compliance under applicable law to reduce exposure to employee claims of discrimination and to efficiently manage workplace issues associated with AIDS. Employers should implement AIDS policies and programs designed to educate their workforce to reduce the spread of AIDS and to clear up any misunderstandings about the disease which could wreak havoc in the workplace. This article summarizes suggested action steps for employers and outside resources to consult for guidance.

  10. Channel capacity and receiver deployment optimization for multi-input multi-output visible light communications.

    PubMed

    Wang, Jin-Yuan; Dai, Jianxin; Guan, Rui; Jia, Linqiong; Wang, Yongjin; Chen, Ming

    2016-06-13

    Multi-input multi-output (MIMO) technique is attractive for visible light communication (VLC), which exploits the high signal-to-noise ratio (SNR) of a single channel to overcome the capacity limitation due to the small modulation bandwidth of the light emitting diode. This paper establishes a MIMO VLC system under the non-negativity, peak power and dimmable average power constraints. Assume that perfect channel state information at the transmitter is known, the MIMO channel is changed to parallel, non-interfering sub-channels by using the singular value decomposition (SVD). Based on the SVD, the lower bound on the channel capacity for MIMO VLC is derived by employing entropy power inequality and variational method. Moreover, by maximizing the derived lower bound on the capacity under the given constraints, the receiver deployment optimization problem is formulated. The problem is solved by employing the principle of particle swarm optimization. Numerical results verify the derived capacity bound and the proposed deployment optimization scheme. PMID:27410325

  11. Sensing using eigenchannels in radio-frequency multiple-input, multiple-output communication systems

    NASA Astrophysics Data System (ADS)

    Bikhazi, Nicolas; Young, William F.; Nguyen, Hung

    2011-06-01

    This paper describes the use of multiple-input, multiple-output (MIMO) communication technology as a radio frequency (RF) sensor. We suggest some possible measures for determining how the changes in MIMO channel are related to objects moving through the MIMO channel. Initially, we examine the singular values of the channel matrix. We further demonstrate the effects of the signal-to-noise ratio (SNR) in conjunction with the target physical properties in the creation of eigenchannels. These eigenchannels represent the key factor in the ability of a MIMO system to perform as an effective sensor. Another important feature of MIMO technology is that it allows us to capture spatial information about the target, beyond the typical time and frequency information. Preliminary experimental results at 750 MHz demonstrate that targets can be detected and distinguished based on these simple measures. For example, a vehicular target is distinguishable from a person or groups of people. Our concept is closely related to a MIMO radar approach. However, a key difference is that we make use of the natural process of establishing a MIMO communication link rather than interrogate a specific physical region via a pulsed RF waveform. MIMO communications requires sounding of the physical environment and the creation of a channel matrix in order to maximize data throughput. We leverage this information about the area of interest already captured by the communication system. This allows the use of a MIMO system for both sensing and communication.

  12. Channel capacity and receiver deployment optimization for multi-input multi-output visible light communications.

    PubMed

    Wang, Jin-Yuan; Dai, Jianxin; Guan, Rui; Jia, Linqiong; Wang, Yongjin; Chen, Ming

    2016-06-13

    Multi-input multi-output (MIMO) technique is attractive for visible light communication (VLC), which exploits the high signal-to-noise ratio (SNR) of a single channel to overcome the capacity limitation due to the small modulation bandwidth of the light emitting diode. This paper establishes a MIMO VLC system under the non-negativity, peak power and dimmable average power constraints. Assume that perfect channel state information at the transmitter is known, the MIMO channel is changed to parallel, non-interfering sub-channels by using the singular value decomposition (SVD). Based on the SVD, the lower bound on the channel capacity for MIMO VLC is derived by employing entropy power inequality and variational method. Moreover, by maximizing the derived lower bound on the capacity under the given constraints, the receiver deployment optimization problem is formulated. The problem is solved by employing the principle of particle swarm optimization. Numerical results verify the derived capacity bound and the proposed deployment optimization scheme.

  13. Constrained adaptation for feedback cancellation in hearing aids.

    PubMed

    Kates, J M

    1999-08-01

    In feedback cancellation in hearing aids, an adaptive filter is used to model the feedback path. The output of the adaptive filter is subtracted from the microphone signal to cancel the acoustic and mechanical feedback picked up by the microphone, thus allowing more gain in the hearing aid. In general, the feedback-cancellation filter adapts on the hearing-aid input signal, and signal cancellation and coloration artifacts can occur for a narrow-band input. In this paper, two procedures for LMS adaptation with a constraint on the magnitude of the adaptive weight vector are derived. The constraints greatly reduce the probability that the adaptive filter will cancel a narrow-band input. Simulation results are used to demonstrate the efficacy of the constrained adaptation. PMID:10462806

  14. Financial Aid Administrators' Views on Simplifying Financial Aid: NASFAA's 2008 Financial Aid Simplification Survey Report

    ERIC Educational Resources Information Center

    National Association of Student Financial Aid Administrators (NJ1), 2008

    2008-01-01

    Despite a decade of simplification efforts, students and families are often still baffled by the student aid process and cringe at the sight of financial aid application forms. Contrary to its purpose of helping students to access college, the student aid application process causes families frustration and confusion that has been cited as an…

  15. Cooperative linear output regulation for networked systems by dynamic measurement output feedback

    NASA Astrophysics Data System (ADS)

    Li, Shaobao; Feng, Gang; Wang, Juan; Luo, Xiaoyuan; Guan, Xinping

    2016-04-01

    This paper investigates the cooperative linear output regulation problem of a class of heterogeneous networked systems with a common reference input but with different disturbances for individual nodes. A novel distributed control law is presented based on dynamic measurement output feedback. It is shown that the overall networked closed-loop control system is asymptotically stable and the output regulation errors asymptotically approach zero as time goes to infinity under a sufficient and necessary condition. Finally, a numerical example is provided to demonstrate the effectiveness of the proposed control law.

  16. Characterizing output bottlenecks in a supercomputer

    SciTech Connect

    Xie, Bing; Chase, Jeffrey; Dillow, David A; Drokin, Oleg; Klasky, Scott A; Oral, H Sarp; Podhorszki, Norbert

    2012-01-01

    Supercomputer I/O loads are often dominated by writes. HPC (High Performance Computing) file systems are designed to absorb these bursty outputs at high bandwidth through massive parallelism. However, the delivered write bandwidth often falls well below the peak. This paper characterizes the data absorption behavior of a center-wide shared Lustre parallel file system on the Jaguar supercomputer. We use a statistical methodology to address the challenges of accurately measuring a shared machine under production load and to obtain the distribution of bandwidth across samples of compute nodes, storage targets, and time intervals. We observe and quantify limitations from competing traffic, contention on storage servers and I/O routers, concurrency limitations in the client compute node operating systems, and the impact of variance (stragglers) on coupled output such as striping. We then examine the implications of our results for application performance and the design of I/O middleware systems on shared supercomputers.

  17. Spacelab output processing system architectural study

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Two different system architectures are presented. The two architectures are derived from two different data flows within the Spacelab Output Processing System. The major differences between these system architectures are in the position of the decommutation function (the first architecture performs decommutation in the latter half of the system and the second architecture performs that function in the front end of the system). In order to be examined, the system was divided into five stand-alone subsystems; Work Assembler, Mass Storage System, Output Processor, Peripheral Pool, and Resource Monitor. The work load of each subsystem was estimated independent of the specific devices to be used. The candidate devices were surveyed from a wide sampling of off-the-shelf devices. Analytical expressions were developed to quantify the projected workload in conjunction with typical devices which would adequately handle the subsystem tasks. All of the study efforts were then directed toward preparing performance and cost curves for each architecture subsystem.

  18. Listening to music affects diurnal variation in muscle power output.

    PubMed

    Chtourou, H; Chaouachi, A; Hammouda, O; Chamari, K; Souissi, N

    2012-01-01

    The purpose of this investigation was to assess the effects of listening to music while warming-up on the diurnal variations of power output during the Wingate test. 12 physical education students underwent four Wingate tests at 07:00 and 17:00 h, after 10 min of warm-up with and without listening to music. The warm-up consisted of 10 min of pedalling at a constant pace of 60 rpm against a light load of 1 kg. During the Wingate test, peak and mean power were measured. The main finding was that peak and mean power improved from morning to afternoon after no music warm-up (p<0.001 and p<0.01, respectively). These diurnal variations disappeared for mean power and persisted with an attenuated morning-evening difference (p<0.05) for peak power after music warm-up. Moreover, peak and mean power were significantly higher after music than no music warm-up during the two times of testing. Thus, as it is a legal method and an additional aid, music should be used during warm-up before performing activities requiring powerful lower limbs' muscles contractions, especially in the morning competitive events.

  19. Averaging Sampled Sensor Outputs To Detect Failures

    NASA Technical Reports Server (NTRS)

    Panossian, Hagop V.

    1990-01-01

    Fluctuating signals smoothed by taking consecutive averages. Sampling-and-averaging technique processes noisy or otherwise erratic signals from number of sensors to obtain indications of failures in complicated system containing sensors. Used under both transient and steady-state conditions. Useful in monitoring automotive engines, chemical-processing plants, powerplants, and other systems in which outputs of sensors contain noise or other fluctuations in measured quantities.

  20. Generalized Input-Output Inequality Systems

    SciTech Connect

    Liu Yingfan Zhang Qinghong

    2006-09-15

    In this paper two types of generalized Leontief input-output inequality systems are introduced. The minimax properties for a class of functions associated with the inequalities are studied. Sufficient and necessary conditions for the inequality systems to have solutions are obtained in terms of the minimax value. Stability analysis for the solution set is provided in terms of upper semi-continuity and hemi-continuity of set-valued maps.

  1. AIDS and family planning.

    PubMed

    1992-01-01

    In 1991, an HIV prevention program advisor and a research/evaluation specialist for family planning programs discussed problems that affected HIV prevention and family planning services in Haiti before and after the coup of the Aristide government. Population activities began aimlessly in 1974 and HIV prevention efforts only began in 1988. After the coup, Haitians lost their newly found hope for meaningful development. All foreign assistance ended and they did not trust the army. In fact, other than essential child survival activities, no health and family planning services operated for several weeks. The situation grew worse after the economic embargo. 3 months after the coup, the US considered adding family planning assistance. Still little movement of condom, family planning, and health supplies left Port-au-Prince for the provinces which adversely affected all health related efforts. Condoms could no longer be distributed easily either in the socially marketed or US supplied condom distribution programs. Before the coup, HIV prevention and family planning programs depended on peer educators to educate the public (this approach made these programs quite successful), but the 2 experts feared that they would not return to those roles and that these programs would need to completely rebuild. Another concern was the large scale urban-rural migration making it difficult for them to continue care. Early in the AIDS epidemic, the Haitian government was on the defensive because the US considered Haitians as a high risk group so it did little to prevent HIV transmission. After 1988, HIV prevention activities in Haiti centered on raising awareness and personalizing the epidemic. The AIDS specialist noted, however, that a major obstacle to increasing knowledge is that AIDS is just 1 of many fatal diseases in Haiti. Moreover few health professionals in Haiti have ever had public health training. PMID:12159262

  2. Characterizing detonator output using dynamic witness plates

    SciTech Connect

    Murphy, Michael John; Adrian, Ronald J

    2009-01-01

    A sub-microsecond, time-resolved micro-particle-image velocimetry (PIV) system is developed to investigate the output of explosive detonators. Detonator output is directed into a transparent solid that serves as a dynamic witness plate and instantaneous shock and material velocities are measured in a two-dimensional plane cutting through the shock wave as it propagates through the solid. For the case of unloaded initiators (e.g. exploding bridge wires, exploding foil initiators, etc.) the witness plate serves as a surrogate for the explosive material that would normally be detonated. The velocity-field measurements quantify the velocity of the shocked material and visualize the geometry of the shocked region. Furthermore, the time-evolution of the velocity-field can be measured at intervals as small as 10 ns using the PIV system. Current experimental results of unloaded exploding bridge wire output in polydimethylsiloxane (PDMS) witness plates demonstrate 20 MHz velocity-field sampling just 300 ns after initiation of the wire.

  3. Cardiac output: a view from Buffalo.

    PubMed

    Olszowka, A J; Shykoff, B E; Pendergast, D R; Lundgren, C E G; Farhi, L E

    2003-10-01

    Cardiac output (Q) is a primary determinant of blood pressure and O2 delivery and is critical in the maintenance of homeostasis, particularly during environmental stress. Cardiac output can be determined invasively in patients; however, indirect methods are required for other situations. Soluble gas techniques are widely used to determine Q. Historically, measurements during a breathhold, prolonged expiration and rebreathing to CO2 equilibrium have been used; however, with limitations, especially during stress. Farhi and co-workers developed a single-step CO2 rebreathing method, which was subsequently revised by his group, and has been shown to be valid (compared to direct measures) and reliable. Carbon dioxide output (VCO2), partial pressure of arterial CO2 (PaCO2), and partial pressure of mixed venous CO2 (Pv(CO2)) are determined during 12-25 s of rebreathing, using the appropriate tidal volume, and Q is calculated. This method has the utility to provide accurate data in laboratory and field experiments during exercise, increased and micro-gravity, water immersion, lower body pressure, head-down tilt, and changes in gas composition and pressure. Utilizing the Buffalo CO2 rebreathing method it has been shown that the Q can adjust to a wide range of changes in environments maintaining blood pressure and O2 delivery at rest and during exercise.

  4. Characterizing Detonator Output Using Dynamic Witness Plates

    NASA Astrophysics Data System (ADS)

    Murphy, Michael J.; Adrian, Ronald J.

    2009-12-01

    A sub-microsecond, time-resolved micro-particle-image velocimetry (PIV) system is developed to investigate the output of explosive detonators. Detonator output is directed into a transparent solid that serves as a dynamic witness plate and instantaneous shock and material velocities are measured in a two-dimensional plane cutting through the shock wave as it propagates through the solid. For the case of unloaded initiators (e.g. exploding bridge wires, exploding foil initiators, etc.) the witness plate serves as a surrogate for the explosive material that would normally be detonated. The velocity-field measurements quantify the velocity of the shocked material and visualize the geometry of the shocked region. Furthermore, the time-evolution of the velocity-field can be measured at intervals as small as 10 ns using the PIV system. Current experimental results of unloaded exploding bridge wire output in polydimethylsiloxane (PDMS) witness plates demonstrate 20 MHz velocity-field sampling just 300 ns after initiation of the wire.

  5. Realistic power output modeling of CPV modules

    NASA Astrophysics Data System (ADS)

    Steiner, Marc; Siefer, Gerald; Bösch, Armin; Hornung, Thorsten; Bett, Andreas W.

    2012-10-01

    In this work, we introduce a new model called YieldOpt, which calculates the power output of CPV modules. It uses SMARTS2 to model the spectral irradiance, a ray tracing program to model the optics and SPICE network simulation to model the electrical characteristic of triple-junction (3J) cells. The calculated power output is compared to data measured of five CPV modules operating in Freiburg, Germany during a period from October 2011 to March 2012. Four of the modules use lattice-matched 3J cells; one of these modules has also reflective secondary optics. In one of the five modules novel metamorphic 3J cells are used. The agreement of the predicted power output calculated by YieldOpt with the measured data is quantified using the normalized root mean square error. A good agreement between simulation and measurement is achieved. Moreover, the predicted energy yield derived from the new model is compared with the measured energy yield. A good agreement between the measured data and simulated data is achieved. In addition, a high accuracy in predicting the energy yield of different CPV modules is demonstrated. Finally, the new model is compared with three empirical models.

  6. Burst Firing Enhances Neural Output Correlation

    PubMed Central

    Chan, Ho Ka; Yang, Dong-Ping; Zhou, Changsong; Nowotny, Thomas

    2016-01-01

    Neurons communicate and transmit information predominantly through spikes. Given that experimentally observed neural spike trains in a variety of brain areas can be highly correlated, it is important to investigate how neurons process correlated inputs. Most previous work in this area studied the problem of correlation transfer analytically by making significant simplifications on neural dynamics. Temporal correlation between inputs that arises from synaptic filtering, for instance, is often ignored when assuming that an input spike can at most generate one output spike. Through numerical simulations of a pair of leaky integrate-and-fire (LIF) neurons receiving correlated inputs, we demonstrate that neurons in the presence of synaptic filtering by slow synapses exhibit strong output correlations. We then show that burst firing plays a central role in enhancing output correlations, which can explain the above-mentioned observation because synaptic filtering induces bursting. The observed changes of correlations are mostly on a long time scale. Our results suggest that other features affecting the prevalence of neural burst firing in biological neurons, e.g., adaptive spiking mechanisms, may play an important role in modulating the overall level of correlations in neural networks. PMID:27242499

  7. The diffuse source at the center of LMC SNR 0509–67.5 is a background galaxy at z = 0.031

    SciTech Connect

    Pagnotta, Ashley; Walker, Emma S.; Schaefer, Bradley E.

    2014-06-20

    Type Ia supernovae (SNe Ia) are well-known for their use in the measurement of cosmological distances, but our continuing lack of concrete knowledge about their progenitor stars is both a matter of debate and a source of systematic error. In our attempts to answer this question, we presented unambiguous evidence that LMC SNR 0509–67.5, the remnant of an SN Ia that exploded in the Large Magellanic Cloud 400 ± 50 yr ago, did not have any point sources (stars) near the site of the original supernova explosion, from which we concluded that this particular supernova must have had a progenitor system consisting of two white dwarfs. There is, however, evidence of nebulosity near the center of the remnant, which could have been left over detritus from the less massive WD, or could have been a background galaxy unrelated to the supernova explosion. We obtained long-slit spectra of the central nebulous region using GMOS on Gemini South to determine which of these two possibilities is correct. The spectra show Hα emission at a redshift of z = 0.031, which implies that the nebulosity in the center of LMC SNR 0509–67.5 is a background galaxy, unrelated to the supernova.

  8. A new framework for particle detection in low-SNR fluorescence live-cell images and its application for improved particle tracking.

    PubMed

    Yang, Lei; Qiu, Zhen; Greenaway, Alan H; Lu, Weiping

    2012-07-01

    Image denoising and signal enhancement are two common steps to improve particle contrast for detection in low-signal-to-noise ratio (SNR) fluorescence live-cell images. However, denoising may oversmooth features of interest, particularly weak features, leading to false negative detection. Here, we propose a robust framework for particle detection in which image denoising in the grayscale image is not needed, so avoiding image oversmoothing. A key to our approach is the new development of a particle enhancement filter based on the recently proposed particle probability image to obtain significantly enhanced particle features and greatly suppressed background in low-SNR and low-contrast environments. The new detection method is formed by combining foreground and background markers with watershed transform operating in both particle probability and grayscale spaces; dynamical switchings between the two spaces can optimally make use the information in images for accurate determination of particle position, size, and intensity. We further develop the interacting multiple mode filter for particle motion modeling and data association by incorporating the extra information obtained from our particle detector to enhance the efficiency of multiple particle tracking. We find that our methods lead to significant improvements in particle detection and tracking efficiency in fluorescence live-cell applications. PMID:22552546

  9. New constraints on the TeV SNR shells RX J1713.7-3946 and HESS J1731-347

    NASA Astrophysics Data System (ADS)

    Puehlhofer, G.; Eger, P.; Doroshenko, V.; Cui, Y.; H. E. S. S. Collaboration

    2016-06-01

    Resolved TeV-emitting supernova remnants remain a small and precious class of sources to study cosmic ray acceleration in SNRs. We present new multi-wavelength results of the two prominent objects RX J1713.7-3946 and HESS J1731-347. For RX J1713.7-3946, extensive new H.E.S.S. data have permitted to study the nature of the TeV-emitting CR particles through improved broadband spectral studies, as well as through detailed investigations of morphological differences between TeV gamma-rays and X-rays. Concerning HESS J1731-347, the TeV morphology of the object and its surroundings has been studied using cosmic ray acceleration simulations of the object. The SNR also hosts a luminous X-ray emitting central compact object (CCO). Investigations of the CCO in X-rays and in the infrared have permitted to set interesting constraints on the SNR and its progenitor.

  10. A new framework for particle detection in low-SNR fluorescence live-cell images and its application for improved particle tracking.

    PubMed

    Yang, Lei; Qiu, Zhen; Greenaway, Alan H; Lu, Weiping

    2012-07-01

    Image denoising and signal enhancement are two common steps to improve particle contrast for detection in low-signal-to-noise ratio (SNR) fluorescence live-cell images. However, denoising may oversmooth features of interest, particularly weak features, leading to false negative detection. Here, we propose a robust framework for particle detection in which image denoising in the grayscale image is not needed, so avoiding image oversmoothing. A key to our approach is the new development of a particle enhancement filter based on the recently proposed particle probability image to obtain significantly enhanced particle features and greatly suppressed background in low-SNR and low-contrast environments. The new detection method is formed by combining foreground and background markers with watershed transform operating in both particle probability and grayscale spaces; dynamical switchings between the two spaces can optimally make use the information in images for accurate determination of particle position, size, and intensity. We further develop the interacting multiple mode filter for particle motion modeling and data association by incorporating the extra information obtained from our particle detector to enhance the efficiency of multiple particle tracking. We find that our methods lead to significant improvements in particle detection and tracking efficiency in fluorescence live-cell applications.

  11. Study Guide for First Aid Practices.

    ERIC Educational Resources Information Center

    Thygerson, Alton L.

    This study guide is designed to accompany the American National Red Cross texts ADVANCED FIRST AID AND EMERGENCY CARE and STANDARD FIRST AID AND PERSONAL SAFETY. Part one serves as an introduction to first aid. The legal aspects of first aid are discussed along with a list of suggested first aid kit contents, and information on first aid books is…

  12. [Adolescence and AIDS].

    PubMed

    1991-01-01

    The myths and prejudices that distort the reality and hide the true causes and effects of natural and social phenomena related to sexuality have a fertile ground in AIDS, given its obvious link to sex. The alarming spread of AIDS has been 1 result of these myths and prejudices. Human beings are sexual by nature; genital organs determine sex and also induce sexual behavior. It is by not fairly well accepted that an individual's sexuality exists from birth. Puberty usually begins at 12-16 years for both sexes. The physical changes of puberty terminate in the ability of the female to conceive and the male to procreate. The sexual excitation of adolescents resulting from production of various hormones can only be eliminated by some type of sexual satisfaction or sublimation. Sexuality, according to Freud, is an organizing principle of the personality. The sexual organs exist not merely for reproduction but to provide pleasure. Puberty signifies entry into active sex life. But the ideological structure of society, perpetuated by the family, schools, religion, the mass media, and other social institutions, sends confused signals to adolescents, requiring abstinence and virginity until marriage for women while encouraging sexual adventures for men. Adolescents are confronted by their new sexual feelings in the midst of a virtual bombardment of visual sexual stimuli from the mass media. It becomes impossible for adolescents to satisfy the requirements of appearances while also resolving the problems and pressures of their newly gained sexual maturity. Many adolescents become sexually active, and the problem is not to prevent sexual activity but to improve the conditions under which it occurs. Adolescents, lacking education and information about sex, begin their sex lives without protection. AIDS has now been added to the list of dire consequences that can result. A true sex education beginning in the home is needed to enable young people to develop healthy and full sex

  13. HIV/AIDS eradication

    PubMed Central

    Marsden, Matthew D.; Zack, Jerome A.

    2013-01-01

    Antiretroviral therapy can inhibit HIV replication in patients and prevent progression to AIDS. However, it is not curative. Here we provide an overview of what antiretroviral drugs do and how the virus persists during therapy in rare reservoirs, such as latently infected CD4+ T cells. We also outline several innovative methods that are currently under development to eradicate HIV from infected individuals. These strategies include gene therapy approaches intended to create an HIV-resistant immune system, and activation/elimination approaches directed towards flushing out latent virus. This latter approach could involve the use of novel chemically synthesized analogs of natural activating agents. PMID:23735743

  14. Revitalizing AIDS activism.

    PubMed

    Wolf, M

    1998-12-01

    Maxine Wolf, an activist with ACT UP New York, suggests ways to motivate others in her organization and revitalize AIDS activism. Reach out to the gay and lesbian community, get them involved in grassroots efforts, and gain their input. Participate in discussions on larger issues such as research, funding, and treatment options. Wolf also suggests becoming educated, acting in a more public way, and finding more creative ways to act. Lastly, strive for goals with high expectations that can effect change instead of merely gathering and dispensing information.

  15. [Adolescence and AIDS].

    PubMed

    1991-01-01

    The myths and prejudices that distort the reality and hide the true causes and effects of natural and social phenomena related to sexuality have a fertile ground in AIDS, given its obvious link to sex. The alarming spread of AIDS has been 1 result of these myths and prejudices. Human beings are sexual by nature; genital organs determine sex and also induce sexual behavior. It is by not fairly well accepted that an individual's sexuality exists from birth. Puberty usually begins at 12-16 years for both sexes. The physical changes of puberty terminate in the ability of the female to conceive and the male to procreate. The sexual excitation of adolescents resulting from production of various hormones can only be eliminated by some type of sexual satisfaction or sublimation. Sexuality, according to Freud, is an organizing principle of the personality. The sexual organs exist not merely for reproduction but to provide pleasure. Puberty signifies entry into active sex life. But the ideological structure of society, perpetuated by the family, schools, religion, the mass media, and other social institutions, sends confused signals to adolescents, requiring abstinence and virginity until marriage for women while encouraging sexual adventures for men. Adolescents are confronted by their new sexual feelings in the midst of a virtual bombardment of visual sexual stimuli from the mass media. It becomes impossible for adolescents to satisfy the requirements of appearances while also resolving the problems and pressures of their newly gained sexual maturity. Many adolescents become sexually active, and the problem is not to prevent sexual activity but to improve the conditions under which it occurs. Adolescents, lacking education and information about sex, begin their sex lives without protection. AIDS has now been added to the list of dire consequences that can result. A true sex education beginning in the home is needed to enable young people to develop healthy and full sex

  16. Refocusing disaster aid.

    PubMed

    Linnerooth-Bayer, Joanne; Mechler, Reinhard; Pflug, Georg

    2005-08-12

    With new modeling techniques for estimating and pricing the risks of natural disasters, the donor community is now in a position to help the poor cope with the economic repercussions of disasters by assisting before they happen. Such assistance is possible with the advent of novel insurance instruments for transferring catastrophe risks to the global financial markets. Donor-supported risk-transfer programs not only would leverage limited disaster-aid budgets but also would free recipient countries from depending on the vagaries of postdisaster assistance. Both donors and recipients stand to gain, especially because the instruments can be closely coupled with preventive measures. PMID:16099976

  17. Should Aid Reward Performance?

    PubMed Central

    Olken, Benjamin A.; Onishi, Junko; Wong, Susan

    2014-01-01

    We report an experiment in 3,000 villages that tested whether incentives improve aid efficacy. Villages received block grants for maternal and child health and education that incorporated relative performance incentives. Subdistricts were randomized into incentives, an otherwise identical program without incentives, or control. Incentives initially improved preventative health indicators, particularly in underdeveloped areas, and spending efficiency increased. While school enrollments improved overall, incentives had no differential impact on education, and incentive health effects diminished over time. Reductions in neonatal mortality in non-incentivized areas did not persist with incentives. We find no systematic scoring manipulation nor funding reallocation toward richer areas. PMID:25485039

  18. Multiple-Input Multiple-Output (MIMO) Linear Systems Extreme Inputs/Outputs

    DOE PAGES

    Smallwood, David O.

    2007-01-01

    A linear structure is excited at multiple points with a stationary normal random process. The response of the structure is measured at multiple outputs. If the autospectral densities of the inputs are specified, the phase relationships between the inputs are derived that will minimize or maximize the trace of the autospectral density matrix of the outputs. If the autospectral densities of the outputs are specified, the phase relationships between the outputs that will minimize or maximize the trace of the input autospectral density matrix are derived. It is shown that other phase relationships and ordinary coherence less than one willmore » result in a trace intermediate between these extremes. Least favorable response and some classes of critical response are special cases of the development. It is shown that the derivation for stationary random waveforms can also be applied to nonstationary random, transients, and deterministic waveforms.« less

  19. Extreme inputs/outputs for multiple input multiple output linear systems.

    SciTech Connect

    Smallwood, David Ora

    2005-09-01

    A linear structure is excited at multiple points with a stationary normal random process. The response of the structure is measured at multiple outputs. If the auto spectral densities of the inputs are specified, the phase relationships between the inputs are derived that will minimize or maximize the trace of the auto spectral density matrix of the outputs. If the autospectral densities of the outputs are specified, the phase relationships between the outputs that will minimize or maximize the trace of the input auto spectral density matrix are derived. It is shown that other phase relationships and ordinary coherence less than one will result in a trace intermediate between these extremes. Least favorable response and some classes of critical response are special cases of the development. It is shown that the derivation for stationary random waveforms can also be applied to nonstationary random, transients, and deterministic waveforms.

  20. Comparison of CAISO-run Plexos output with LLNL-run Plexos output

    SciTech Connect

    Schmidt, A; Meyers, C; Smith, S

    2011-12-20

    In this report we compare the output of the California Independent System Operator (CAISO) 33% RPS Plexos model when run on various computing systems. Specifically, we compare the output resulting from running the model on CAISO's computers (Windows) and LLNL's computers (both Windows and Linux). We conclude that the differences between the three results are negligible in the context of the entire system and likely attributed to minor differences in Plexos version numbers as well as the MIP solver used in each case.

  1. [Women and AIDS in Africa].

    PubMed

    Coll Seck, A M

    1990-10-01

    The theme of "World Aids Day" for 1990 was "Women and AIDS." This theme was chosen because of the devastating effects AIDS has on women. The World Health Organization's (WHO) latest figures state that women represent 1/3 of the estimated 6 million people infected with AIDS worldwide. The majority of these women are in Sub-Saharan Africa (SSA) and the Caribbean. The outcomes of a recent study done in a Central African country showed that women were 4 times more susceptible to getting AIDS than men, in spite of the fact that there are more men than women in this area of SSA. The reasons that women are so vulnerable are multiple: illiteracy, lack of access to information, prejudices, sexual taboos, and an economic dependency which have all led women towards prostitution and the growing incidence of hetero sexual transmission of AIDS in SSA. Prostitutes are 88% seropositive in Kigali; 16% in Dakar and 90% in Nairobi. 10% of all AIDS cases in SSA are due to transfusions where the blood banks are not monitored because women are loosing large quantities of blood through abortions, hemorrhages, deliveries and chronic anemia due to continuous pregnancies that are badly spaced. Additional problems for women are transmitting AIDS to their babies -- 25-30% of pediatric AIDS are transmitted from mother to child through "vertical transmission (VT)." This VT is a serious problem in East Africa where a survey in Uganda showed that 24% of pregnant women were infected with AIDS. The WHO estimated that between 1980-1987, 80,000 children were infected with AIDS of which 80% died before age 5. AIDS in SSA is taking its toll on women who face environmental, socio-cultural, political and economic discrimination. Such a loss to AIDS to incalculable to society.

  2. Epigenetic regulation of HIV, AIDS, and AIDS-related malignancies.

    PubMed

    Verma, Mukesh

    2015-01-01

    Although epigenetics is not a new field, its implications for acquired immunodeficiency syndrome (AIDS) research have not been explored fully. To develop therapeutic and preventive approaches against the human immunodeficiency virus (HIV) and AIDS, it is essential to understand the mechanisms of interaction between the virus and the host, involvement of genetic and epigenetic mechanisms, characterization of viral reservoirs, and factors influencing the latency of the virus. Both methylation of viral genes and histone modifications contribute to initiating and maintaining latency and, depending on the context, triggering viral gene repression or expression. This chapter discusses progress made at the National Institutes of Health (NIH), recommendations from the International AIDS Society Scientific Working Group on HIV Cure, and underlying epigenetic regulation. A number of epigenetic inhibitors have shown potential in treating AIDS-related malignancies. Epigenetic drugs approved by the US Food and Drug Administration and their implications for the eradication of HIV/AIDS and AIDS-related malignancies also are discussed.Past and current progress in developing treatments and understanding the molecular mechanisms of AIDS and HIV infection has greatly improved patient survival. However, increased survival has been coupled with the development of cancer at higher rates than those observed among the HIV/AIDS-negative population. During the early days of the AIDS epidemic, the most frequent AIDS-defining malignancies were Kaposi's sarcoma and non-Hodgkin lymphoma (NHL). Now, with increased survival as the result of widespread use in the developed world of highly active antiretroviral therapy (HAART), non-AIDS defining cancers (i.e., anal, skin, and lung cancers, and Hodgkin disease) are on the increase in HIV-infected populations. The current status of AIDS-related malignancies also is discussed.

  3. Fuel dispenser aid

    SciTech Connect

    Bobst, J.M.

    1993-08-31

    A fuel dispenser aid is described for holding a trigger-like valve operating lever relative to a pistol grip-like handle portion of a valving device for dispensing gasoline or other fuels through a nozzle of the valving device, said fuel dispenser aid comprising: a mounting member formed of a material having a resilient, shape retaining character and configured for mounting over the pistol grip-like handle portion of the valving device, a flexible strap secured at a first end thereof to the mounting member and extending freely therefrom such that when the mounting member is mounted over the pistol grip-like handle portion of the valving device the free portion of the strap can he looped under the trigger-like valve operating lever and up to the mounting member, and fastening means for releasably and adjustably fastening the free portion of the strap to the mounting member after the free portion of the strap has been looped under the valve operating lever and up to the mounting member whereby the valve operating lever can be held in a desired set position relative to the handle portion of the valving device for dispensing fuel without requiring that the operating lever of the valving device continuously be manually held in said set position.

  4. Bone Anchored Hearing Aid

    PubMed Central

    2002-01-01

    Executive Summary Objective The objective of this health technology policy assessment was to determine the effectiveness and cost-effectiveness of bone-anchored hearing aid (BAHA) in improving the hearing of people with conduction or mixed hearing loss. The Technology The (BAHA) is a bone conduction hearing device that includes a titanium fixture permanently implanted into the mastoid bone of the skull and an external percutaneous sound processor. The sound processor is attached to the fixture by means of a skin penetrating abutment. Because the device bypasses the middle ear and directly stimulates the cochlea, it has been recommended for individuals with conduction hearing loss or discharging middle ear infection. The titanium implant is expected to last a lifetime while the external sound processor is expected to last 5 years. The total initial device cost is approximately $5,300 and the external sound processor costs approximately $3,500. Review of BAHA by the Medical Advisory Secretariat The Medical Advisory Secretariat’s review is a descriptive synthesis of findings from 36 research articles published between January 1990 and May 2002. Summary of Findings No randomized controlled studies were found. The evidence was derived from level 4 case series with relative small sample sizes (ranging from 30-188). The majority of the studies have follow-up periods of eight years or longer. All except one study were based on monaural BAHA implant on the side with the best bone conduction threshold. Safety Level 4 evidence showed that BAHA has been be implanted safely in adults and children with success rates of 90% or higher in most studies. No mortality or life threatening morbidity has been reported. Revision rates for tissue reduction or resiting were generally under 10% for adults but have been reported to be as high as 25% in pediatric studies. Adverse skin reaction around the skin penetration site was the most common complication reported. Most of these

  5. Measurement of hearing aid internal noise.

    PubMed

    Lewis, James D; Goodman, Shawn S; Bentler, Ruth A

    2010-04-01

    Hearing aid equivalent input noise (EIN) measures assume the primary source of internal noise to be located prior to amplification and to be constant regardless of input level. EIN will underestimate internal noise in the case that noise is generated following amplification. The present study investigated the internal noise levels of six hearing aids (HAs). Concurrent with HA processing of a speech-like stimulus with both adaptive features (acoustic feedback cancellation, digital noise reduction, microphone directionality) enabled and disabled, internal noise was quantified for various stimulus levels as the variance across repeated trials. Changes in noise level as a function of stimulus level demonstrated that (1) generation of internal noise is not isolated to the microphone, (2) noise may be dependent on input level, and (3) certain adaptive features may contribute to internal noise. Quantifying internal noise as the variance of the output measures allows for noise to be measured under real-world processing conditions, accounts for all sources of noise, and is predictive of internal noise audibility. PMID:20370034

  6. Measurement of hearing aid internal noise1

    PubMed Central

    Lewis, James D.; Goodman, Shawn S.; Bentler, Ruth A.

    2010-01-01

    Hearing aid equivalent input noise (EIN) measures assume the primary source of internal noise to be located prior to amplification and to be constant regardless of input level. EIN will underestimate internal noise in the case that noise is generated following amplification. The present study investigated the internal noise levels of six hearing aids (HAs). Concurrent with HA processing of a speech-like stimulus with both adaptive features (acoustic feedback cancellation, digital noise reduction, microphone directionality) enabled and disabled, internal noise was quantified for various stimulus levels as the variance across repeated trials. Changes in noise level as a function of stimulus level demonstrated that (1) generation of internal noise is not isolated to the microphone, (2) noise may be dependent on input level, and (3) certain adaptive features may contribute to internal noise. Quantifying internal noise as the variance of the output measures allows for noise to be measured under real-world processing conditions, accounts for all sources of noise, and is predictive of internal noise audibility. PMID:20370034

  7. Is AGC beneficial in hearing aids?

    PubMed

    King, A B; Martin, M C

    1984-02-01

    Three different functions of Automatic Gain Control (AGC) circuits in hearing aids are distinguished and the evidence for their benefits is considered. The value of AGC's function as a relatively distortion-free means of limiting output has been well established. With regard to compression, the benefit of short-term or 'syllabic' compression has not been demonstrated convincingly. Most evaluations of this type of AGC have looked for increase in speech intelligibility, but theoretical predictions of its effect do not appear to take account of the acoustic cues to consonant contrasts actually used by hearing impaired people, and empirical studies have often used listening conditions which do not give a realistic test of benefit. Relatively little attention has been paid to long-term compression, or to the effect of AGC on comfort rather than intelligibility. Listening tests carried out at the RNID and reported here have shown that AGC can benefit hearing aid users by allowing them to listen to a wider range of sound levels without either strain or discomfort, and, if time constants are well chosen, without adverse effects on speech intelligibility in quiet or in noise.

  8. A code-aided carrier synchronization algorithm based on improved nonbinary low-density parity-check codes

    NASA Astrophysics Data System (ADS)

    Bai, Cheng-lin; Cheng, Zhi-hui

    2016-09-01

    In order to further improve the carrier synchronization estimation range and accuracy at low signal-to-noise ratio ( SNR), this paper proposes a code-aided carrier synchronization algorithm based on improved nonbinary low-density parity-check (NB-LDPC) codes to study the polarization-division-multiplexing coherent optical orthogonal frequency division multiplexing (PDM-CO-OFDM) system performance in the cases of quadrature phase shift keying (QPSK) and 16 quadrature amplitude modulation (16-QAM) modes. The simulation results indicate that this algorithm can enlarge frequency and phase offset estimation ranges and enhance accuracy of the system greatly, and the bit error rate ( BER) performance of the system is improved effectively compared with that of the system employing traditional NB-LDPC code-aided carrier synchronization algorithm.

  9. Frequency-Shift Hearing Aid

    NASA Technical Reports Server (NTRS)

    Weinstein, Leonard M.

    1994-01-01

    Proposed hearing aid maps spectrum of speech into band of lower frequencies at which ear remains sensitive. By redirecting normal speech frequencies into frequency band from 100 to 1,500 Hz, hearing aid allows people to understand normal conversation, including telephone calls. Principle operation of hearing aid adapted to other uses such as, clearing up noisy telephone or radio communication. In addition, loud-speakers more easily understood in presence of high background noise.

  10. [Case report: swallowed hearing aid].

    PubMed

    Walther, E K

    1995-11-01

    An 86-year-old man presented ambulatory with acute dysphagia. Radiologic examination and endoscopy revealed a swallowed postauricular hearing aid. The earmold of the hearing aid became visible in the hypopharynx after mucus and saliva were removed. It could be extracted without effort once the connecting tube was disconnected from the coupling device lodged in the upper esophageal sphincter. The hearing aid itself was impacted in the proximal esophagus and was extracted without any problems. The postoperative phase was uneventful with normal swallowing and discharge. Technical inspection revealed that the hearing aid no longer worked. Diffusion of toxic substances (zinc, mercury) from the impacted batteries is not to be expected.

  11. Public knowledge about AIDS increasing.

    PubMed

    Campbell, M J; Waters, W E

    1987-04-01

    In response to concern over the perceived limited effectiveness of Department of Health and Social Security (UK) advertising campaigns to inform the public of the basic facts of Acquired Immunodeficiency Syndrome (AIDS), a prospective questionnaire study was undertaken in Southampton, England to test the effectiveness of government education prior to a January, 1987 government television/leaflet advertising campaign. 300 questionnaires about AIDS were mailed in December of 1986 to a sample drawn from electoral rolls. The response rate was 61%. Most of the questions were drawn from material covered in the campaign. The results seemed to indicate a small overall increase in knowledge about AIDS. Some changes from a June survey were noted, e.g.: more people were aware that AIDS is a virus for which there is no cure and that it is not readily transmitted by sharing washing, eating or drinking utensils; more people believed that the statement that women are at greater risk for catching AIDS is false. Respondents were generally favorable to the government's continued use of television, even with explicit language, and to its use of the schools, for AIDS education. Many were not aware of the dangers to intravenous drug users or of the symptoms of AIDS. Other surveys have shown an increasing knowledge of AIDS dangers. It is possible that television coverage of the problem will continue to be necessary, in order that less literate populations be reached. Further AIDS health education in general is needed. PMID:3105789

  12. Combining Multiple Gyroscope Outputs for Increased Accuracy

    NASA Technical Reports Server (NTRS)

    Bayard, David S.

    2003-01-01

    A proposed method of processing the outputs of multiple gyroscopes to increase the accuracy of rate (that is, angular-velocity) readings has been developed theoretically and demonstrated by computer simulation. Although the method is applicable, in principle, to any gyroscopes, it is intended especially for application to gyroscopes that are parts of microelectromechanical systems (MEMS). The method is based on the concept that the collective performance of multiple, relatively inexpensive, nominally identical devices can be better than that of one of the devices considered by itself. The method would make it possible to synthesize the readings of a single, more accurate gyroscope (a virtual gyroscope) from the outputs of a large number of microscopic gyroscopes fabricated together on a single MEMS chip. The big advantage would be that the combination of the MEMS gyroscope array and the processing circuitry needed to implement the method would be smaller, lighter in weight, and less power-hungry, relative to a conventional gyroscope of equal accuracy. The method (see figure) is one of combining and filtering the digitized outputs of multiple gyroscopes to obtain minimum-variance estimates of rate. In the combining-and-filtering operations, measurement data from the gyroscopes would be weighted and smoothed with respect to each other according to the gain matrix of a minimum- variance filter. According to Kalman-filter theory, the gain matrix of the minimum-variance filter is uniquely specified by the filter covariance, which propagates according to a matrix Riccati equation. The present method incorporates an exact analytical solution of this equation.

  13. The output from human inspiratory motoneurone pools

    PubMed Central

    Butler, Jane E; Gandevia, Simon C

    2008-01-01

    Survival requires adequate pulmonary ventilation which, in turn, depends on adequate contraction of muscles acting on the chest wall in the presence of a patent upper airway. Bulbospinal outputs projecting directly and indirectly to ‘obligatory’ respiratory motoneurone pools generate the required muscle contractions. Recent studies of the phasic inspiratory output of populations of single motor units to five muscles acting on the chest wall (including the diaphragm) reveal that the time of onset, the progressive recruitment, and the amount of motoneuronal drive (expressed as firing frequency) differ among the muscles. Tonic firing with an inspiratory modulation of firing rate is common in low intercostal spaces of the parasternal and external intercostal muscles but rare in the diaphragm. A new time and frequency plot has been developed to depict the behaviour of the motoneurone populations. The magnitude of inspiratory firing of motor unit populations is linearly correlated to the mechanical advantage of the intercostal muscle region at which the motor unit activity is recorded. This represents a ‘neuromechanical’ principle by which the CNS controls motoneuronal output according to mechanical advantage, presumably in addition to the Henneman's size principle of motoneurone recruitment. Studies of the genioglossus, an obligatory upper airway muscle that helps maintain airway patency, reveal that it receives simultaneous inspiratory, expiratory and tonic drives even during quiet breathing. There is much to be learned about the neural drive to pools of human inspiratory and expiratory muscles, not only during respiratory tasks but also in automatic and volitional tasks, and in diseases that alter the required drive. PMID:17974589

  14. Input and output constraints affecting irrigation development

    NASA Astrophysics Data System (ADS)

    Schramm, G.

    1981-05-01

    In many of the developing countries the expansion of irrigated agriculture is used as a major development tool for bringing about increases in agricultural output, rural economic growth and income distribution. Apart from constraints imposed by water availability, the major limitations considered to any acceleration of such programs are usually thought to be those of costs and financial resources. However, as is shown on the basis of empirical data drawn from Mexico, in reality the feasibility and effectiveness of such development programs is even more constrained by the lack of specialized physical and human factors on the input and market limitations on the output side. On the input side, the limited availability of complementary factors such as, for example, truly functioning credit systems for small-scale farmers or effective agricultural extension services impose long-term constraints on development. On the output side the limited availability, high risk, and relatively slow growth of markets for high-value crops sharply reduce the usually hoped-for and projected profitable crop mix that would warrant the frequently high costs of irrigation investments. Three conclusions are drawn: (1) Factors in limited supply have to be shadow-priced to reflect their high opportunity costs in alternative uses. (2) Re-allocation of financial resources from immediate construction of projects to longer-term increase in the supply of scarce, highly-trained manpower resources are necessary in order to optimize development over time. (3) Inclusion of high-value, high-income producing crops in the benefit-cost analysis of new projects is inappropriate if these crops could potentially be grown in already existing projects.

  15. Uncertainties in predicting solar panel power output

    NASA Technical Reports Server (NTRS)

    Anspaugh, B.

    1974-01-01

    The problem of calculating solar panel power output at launch and during a space mission is considered. The major sources of uncertainty and error in predicting the post launch electrical performance of the panel are considered. A general discussion of error analysis is given. Examples of uncertainty calculations are included. A general method of calculating the effect on the panel of various degrading environments is presented, with references supplied for specific methods. A technique for sizing a solar panel for a required mission power profile is developed.

  16. Inductive Output Tubes -- Status and Future Direction

    NASA Astrophysics Data System (ADS)

    Bohlen, Heinz

    2002-08-01

    Invented in 1938, at the same time as the klystron, it took the Inductive Output Tube (IOT) more than 40 years to surface as a useful device. Its progress after that event was rapid. Though plagued by teething problems in the beginning, it has since replaced the klystron as a TV amplifier in UHF, and it holds its own against the solid-state competition in that application. The IOT also shows much promise as a high-power amplifier, but early developments in this direction have remained solitary events so far. The paper discusses the causes and the potential of the device for future high-power applications.

  17. HCN laser with an adaptive output mirror

    SciTech Connect

    Kamenev, Yu E; Masalov, S A; Filimonova, A A

    2006-09-30

    A device for optimal coupling between a laser resonator and the external medium, having the form of one-dimensional wire grating conjugated with a plane mirror with an aperture, is proposed, developed and tested experimentally. The dependences of the output laser power on the separation between the grating and the mirror, diameter of the aperture in the plane mirror, and the grating period, are studied. The obtained results not only confirm the possibility of using such a coupling device, but also point towards the ways and principles of its application. (lasers)

  18. Off-set stabilizer for comparator output

    DOEpatents

    Lunsford, James S.

    1991-01-01

    A stabilized off-set voltage is input as the reference voltage to a comparator. In application to a time-interval meter, the comparator output generates a timing interval which is independent of drift in the initial voltage across the timing capacitor. A precision resistor and operational amplifier charge a capacitor to a voltage which is precisely offset from the initial voltage. The capacitance of the reference capacitor is selected so that substantially no voltage drop is obtained in the reference voltage applied to the comparator during the interval to be measured.

  19. Input-output-controlled nonlinear equation solvers

    NASA Technical Reports Server (NTRS)

    Padovan, Joseph

    1988-01-01

    To upgrade the efficiency and stability of the successive substitution (SS) and Newton-Raphson (NR) schemes, the concept of input-output-controlled solvers (IOCS) is introduced. By employing the formal properties of the constrained version of the SS and NR schemes, the IOCS algorithm can handle indefiniteness of the system Jacobian, can maintain iterate monotonicity, and provide for separate control of load incrementation and iterate excursions, as well as having other features. To illustrate the algorithmic properties, the results for several benchmark examples are presented. These define the associated numerical efficiency and stability of the IOCS.

  20. Example of input-output analysis

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The thirty sectors included in the ECASTAR energy input-output model were listed. Five of these belong to energy producing sectors, fifteen to manufacturing industries, two to residential and commercial sectors, and eight to service industries. The model is capable of tracing impacts of an action in three dimensions: dollars, BTU's of energy, and labor. Four conservation actions considered were listed and then discussed separately, dealing with the following areas: increase in fuel efficiency, reduction in fuel used by the transportation and warehousing group, manufacturing of smaller automobiles, and a communications/transportation trade-off.

  1. Aids and Infectious Diseases (aid) Pmp 2013 Report

    NASA Astrophysics Data System (ADS)

    Buonaguro, Franco M.

    2014-07-01

    The AIDS and Infectious Diseases (AID) PMP of the WFS contributed this year with a session on August 22nd to the Plenary Sessions of the International Seminars on Planetary Emergencies and Associated Meetings--46th Session: The Role of Science in the Third Millennium (Erice, 19-24 August 2013). Furthermore a workshop on August 24th was organized...

  2. Learning to aid learning.

    PubMed

    Richards, Jacqui

    2016-01-01

    The National Health Service (NHS) is one of the largest employers in the world and, with 1.3 million staff, the biggest employer in Europe. With over three hundred different careers on offer (NHS 2015), the acquisition of skills and qualifications, through academic and clinical training, is an integral part of day-to-day life in the health service. As such, mentoring has become a significant feature in the preparation of healthcare professionals, to support students and ensure learning needs and experiences are appropriate to competency. This article examines the mentor's role, in relation to a teaching innovation designed to address students' identified learning needs to meet the requirements of the multi-professional learning and assessment in practice course NM6156. The effectiveness of the aids to learning will be assessed through an online quiz, and its usefulness will be analysed with reference to educational theories of learning and development.

  3. Neurologic presentations of AIDS.

    PubMed

    Singer, Elyse J; Valdes-Sueiras, Miguel; Commins, Deborah; Levine, Andrew

    2010-02-01

    The human immunodeficiency virus (HIV), the cause of AIDS, has infected an estimated 33 million individuals worldwide. HIV is associated with immunodeficiency, neoplasia, and neurologic disease. The continuing evolution of the HIV epidemic has spurred an intense interest in a hitherto neglected area of medicine, neuroinfectious diseases and their consequences. This work has broad applications for the study of central nervous system (CNS) tumors, dementias, neuropathies, and CNS disease in other immunosuppressed individuals. HIV is neuroinvasive (can enter the CNS), neurotrophic (can live in neural tissues), and neurovirulent (causes disease of the nervous system). This article reviews the HIV-associated neurologic syndromes, which can be classified as primary HIV neurologic disease (in which HIV is both necessary and sufficient to cause the illness), secondary or opportunistic neurologic disease (in which HIV interacts with other pathogens, resulting in opportunistic infections and tumors), and treatment-related neurologic disease (such as immune reconstitution inflammatory syndrome). PMID:19932385

  4. Learning to aid learning.

    PubMed

    Richards, Jacqui

    2016-01-01

    The National Health Service (NHS) is one of the largest employers in the world and, with 1.3 million staff, the biggest employer in Europe. With over three hundred different careers on offer (NHS 2015), the acquisition of skills and qualifications, through academic and clinical training, is an integral part of day-to-day life in the health service. As such, mentoring has become a significant feature in the preparation of healthcare professionals, to support students and ensure learning needs and experiences are appropriate to competency. This article examines the mentor's role, in relation to a teaching innovation designed to address students' identified learning needs to meet the requirements of the multi-professional learning and assessment in practice course NM6156. The effectiveness of the aids to learning will be assessed through an online quiz, and its usefulness will be analysed with reference to educational theories of learning and development. PMID:26975128

  5. The range scheduling aid

    NASA Technical Reports Server (NTRS)

    Halbfinger, Eliezer M.; Smith, Barry D.

    1991-01-01

    The Air Force Space Command schedules telemetry, tracking and control activities across the Air Force Satellite Control network. The Range Scheduling Aid (RSA) is a rapid prototype combining a user-friendly, portable, graphical interface with a sophisticated object-oriented database. The RSA has been a rapid prototyping effort whose purpose is to elucidate and define suitable technology for enhancing the performance of the range schedulers. Designing a system to assist schedulers in their task and using their current techniques as well as enhancements enabled by an electronic environment, has created a continuously developing model that will serve as a standard for future range scheduling systems. The RSA system is easy to use, easily ported between platforms, fast, and provides a set of tools for the scheduler that substantially increases his productivity.

  6. Ergogenic Aids and Supplements.

    PubMed

    Porrini, Marisa; Del Boʼ, Cristian

    2016-01-01

    Great interest is currently shown for the contribution of nutrition to optimize training and athletic performance, and a considerable debate exists about the potential ergogenic value of several dietary supplements. However, most of the products used by athletes do not provide sufficient scientific evidence regarding their efficacy in enhancing physical performance as well as their specificity of action and safety. For this reason, sport nutrition professionals need skills in evaluating the scientific value of papers and advertisements on ergogenic aids and supplements in order to support athletes in their choice. In the present chapter, the efficacy of some of the most popular supplements used by athletes and sport practitioners will be discussed. Particular attention will be devoted to amino acids and derivatives, caffeine and caffeinated energy drinks, and some antioxidants.

  7. Ergogenic Aids and Supplements.

    PubMed

    Porrini, Marisa; Del Boʼ, Cristian

    2016-01-01

    Great interest is currently shown for the contribution of nutrition to optimize training and athletic performance, and a considerable debate exists about the potential ergogenic value of several dietary supplements. However, most of the products used by athletes do not provide sufficient scientific evidence regarding their efficacy in enhancing physical performance as well as their specificity of action and safety. For this reason, sport nutrition professionals need skills in evaluating the scientific value of papers and advertisements on ergogenic aids and supplements in order to support athletes in their choice. In the present chapter, the efficacy of some of the most popular supplements used by athletes and sport practitioners will be discussed. Particular attention will be devoted to amino acids and derivatives, caffeine and caffeinated energy drinks, and some antioxidants. PMID:27348226

  8. AIDS and sex tourism.

    PubMed

    Herold, E S; Van Kerkwijk, C

    1992-01-01

    Tourists traveling internationally lower their inhibitions and take greater risks than they would typically in their home cultures. Loneliness, boredom, and a sense of freedom contribute to this behavioral change. Some tourists travel internationally in search of sexual gratification. This motivation may be actively conscious or subconscious to the traveler. Billed as romantic with great natural beauty, Thailand, the Philippines, Brazil, the Dominican Republic, and Kenya are popular destinations of tourists seeking sex. The Netherlands and countries in eastern Europe are also popular. With most initial cases of HIV infection in Europe having histories of international travel, mass tourism is a major factor in the international transmission of AIDS. While abroad, tourists have sex with casual partners, sex workers, and/or other tourists. Far from all tourists, however, carry and consistently use condoms with these partners. One study found female and non white travelers to be less likely than Whites and males to carry condoms. The risk of HIV infection increases in circumstances where condoms are not readily available in the host country and/or are of poor quality. Regarding actual condom use, a study found only 34% of sex tourists from Switzerland to consistently use condoms while abroad. 28% of men in an STD clinic in Melbourne, Australia, reported consistent condom use in sexual relations while traveling in Asia; STDs were identified in 73% of men examined. The few studies of tourists suggest that a significant proportion engage in risky behavior while traveling. HIV prevalence is rapidly increasing in countries known as destinations for sex tourism. High infection rates are especially evident among teenage sex workers in Thailand. Simply documenting the prevalence of risky behavior among sex tourists will not suffice. More research is needed on travelers and AIDS with particular attention upon the motivating factors supporting persistent high-risk behavior.

  9. AIDS and sex tourism.

    PubMed

    Herold, E S; Van Kerkwijk, C

    1992-01-01

    Tourists traveling internationally lower their inhibitions and take greater risks than they would typically in their home cultures. Loneliness, boredom, and a sense of freedom contribute to this behavioral change. Some tourists travel internationally in search of sexual gratification. This motivation may be actively conscious or subconscious to the traveler. Billed as romantic with great natural beauty, Thailand, the Philippines, Brazil, the Dominican Republic, and Kenya are popular destinations of tourists seeking sex. The Netherlands and countries in eastern Europe are also popular. With most initial cases of HIV infection in Europe having histories of international travel, mass tourism is a major factor in the international transmission of AIDS. While abroad, tourists have sex with casual partners, sex workers, and/or other tourists. Far from all tourists, however, carry and consistently use condoms with these partners. One study found female and non white travelers to be less likely than Whites and males to carry condoms. The risk of HIV infection increases in circumstances where condoms are not readily available in the host country and/or are of poor quality. Regarding actual condom use, a study found only 34% of sex tourists from Switzerland to consistently use condoms while abroad. 28% of men in an STD clinic in Melbourne, Australia, reported consistent condom use in sexual relations while traveling in Asia; STDs were identified in 73% of men examined. The few studies of tourists suggest that a significant proportion engage in risky behavior while traveling. HIV prevalence is rapidly increasing in countries known as destinations for sex tourism. High infection rates are especially evident among teenage sex workers in Thailand. Simply documenting the prevalence of risky behavior among sex tourists will not suffice. More research is needed on travelers and AIDS with particular attention upon the motivating factors supporting persistent high-risk behavior. PMID

  10. [AIDS information in Zimbabwe].

    PubMed

    Meyer, L

    1993-11-20

    The difficulties of health education concerning AIDs prevention in Zimbabwe include communicating simple information about complicated processes, resistance to the information because of status or tradition, and lack of experience with translating material that was produced in the West. The beliefs in ghosts and witch doctors are still part of the tradition in Zimbabwe, providing cultural diversity and a sense of identification. Traditional medicine is characterized by Westerners as often irrational behavior that is deleterious to one's health. However, even in the allegedly educated part of the world compliance is often lacking and alternative treatment forms are actively pursued in tandem with formal medicine. When there is a short time period between harmful behavior and infection, most people realize that there is a causative connection. On the other hand, it is a more complicated mental exercise to fathom that intercourse can result in HIV infection that 5 years later may lead to death from tuberculosis. No other disease is known by these people that has a corresponding delay from the time of infection to disease or death. It is also confusing that a sexually transmitted disease does not produce symptoms such as discharge or genital sores. It is difficult to comprehend that a sole causative agent, HIV, can lead to so many different diseases and symptoms. When a young man died after having been hospitalized with protracted cough and TB as a result of HIV infection that he had contracted from a girlfriend, the father told the folks at home that his son had died of TB. These conflicting pieces of information make AIDS prevention education wrought with difficulties, which adds to the rapid spread of the disease, although the authorities and international organizations have responded with strategies, informational materials, and educational courses. PMID:8273086

  11. Electronic filters, signal conversion apparatus, hearing aids and methods

    NASA Technical Reports Server (NTRS)

    Morley, Jr., Robert E. (Inventor); Engebretson, A. Maynard (Inventor); Engel, George L. (Inventor); Sullivan, Thomas J. (Inventor)

    1994-01-01

    An electronic filter for filtering an electrical signal. Signal processing circuitry therein includes a logarithmic filter having a series of filter stages with inputs and outputs in cascade and respective circuits associated with the filter stages for storing electrical representations of filter parameters. The filter stages include circuits for respectively adding the electrical representations of the filter parameters to the electrical signal to be filtered thereby producing a set of filter sum signals. At least one of the filter stages includes circuitry for producing a filter signal in substantially logarithmic form at its output by combining a filter sum signal for that filter stage with a signal from an output of another filter stage. The signal processing circuitry produces an intermediate output signal, and a multiplexer connected to the signal processing circuit multiplexes the intermediate output signal with the electrical signal to be filtered so that the logarithmic filter operates as both a logarithmic prefilter and a logarithmic postfilter. Other electronic filters, signal conversion apparatus, electroacoustic systems, hearing aids and methods are also disclosed.

  12. Saturated output tabletop x-ray lasers

    SciTech Connect

    Dunn, J; Osterheld, A L; Nilsen, J; Hunter, J R; Li, Y; Faenov, A Ya; Pikuz, T A; Shlyaptsev, N

    2000-12-01

    The high efficiency method of transient collisional excitation has been successfully demonstrated for Ne-like and Ni-like ion x-ray laser schemes with small 5-10 J laser facilities. Our recent studies using the tabletop COMET (Compact Multipulse Terawatt) laser system at the Lawrence Livermore National Laboratory (LLNL) have produced several x-ray lasers operating in the saturation regime. Output energy of 10-15 {micro}J corresponding to a gL product of 18 has been achieved on the Ni-like Pd 4d {yields} 4p transition at 147 {angstrom} with a total energy of 5-7 J in a 600 ps pulse followed by a 1.2 ps pulse. Analysis of the laser beam angular profile indicates that refraction plays an important role in the amplification and propagation process in the plasma column. We report further improvement in the extraction efficiency by varying a number of laser driver parameters. In particular, the duration of the second short pulse producing the inversion has an observed effect on the x-ray laser output.

  13. Input-output dynamic mode decomposition

    NASA Astrophysics Data System (ADS)

    Annoni, Jennifer; Jovanovic, Mihailo; Nichols, Joseph; Seiler, Peter

    2015-11-01

    The objective of this work is to obtain reduced-order models for fluid flows that can be used for control design. High-fidelity computational fluid dynamic models provide accurate characterizations of complex flow dynamics but are not suitable for control design due to their prohibitive computational complexity. A variety of methods, including proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD), can be used to extract the dominant flow structures and obtain reduced-order models. In this presentation, we introduce an extension to DMD that can handle problems with inputs and outputs. The proposed method, termed input-output dynamic mode decomposition (IODMD), utilizes a subspace identification technique to obtain models of low-complexity. We show that, relative to standard DMD, the introduction of the external forcing in IODMD provides robustness with respect to small disturbances and noise. We use the linearized Navier-Stokes equations in a channel flow to demonstrate the utility of the proposed approach and to provide a comparison with standard techniques for obtaining reduced-order dynamical representations. NSF Career Grant No. NSFCMMI-1254129.

  14. Doppler-shift estimation of flat underwater channel using data-aided least-square approach

    NASA Astrophysics Data System (ADS)

    Pan, Weiqiang; Liu, Ping; Chen, Fangjiong; Ji, Fei; Feng, Jing

    2015-06-01

    In this paper we proposed a dada-aided Doppler estimation method for underwater acoustic communication. The training sequence is non-dedicate, hence it can be designed for Doppler estimation as well as channel equalization. We assume the channel has been equalized and consider only flat-fading channel. First, based on the training symbols the theoretical received sequence is composed. Next the least square principle is applied to build the objective function, which minimizes the error between the composed and the actual received signal. Then an iterative approach is applied to solve the least square problem. The proposed approach involves an outer loop and inner loop, which resolve the channel gain and Doppler coefficient, respectively. The theoretical performance bound, i.e. the Cramer-Rao Lower Bound (CRLB) of estimation is also derived. Computer simulations results show that the proposed algorithm achieves the CRLB in medium to high SNR cases.

  15. 36 CFR 1193.43 - Output, display, and control functions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and use the product, including but not limited to, text, static or dynamic images, icons, labels... interference to hearing technologies (including hearing aids, cochlear implants, and assistive listening... means for effective wireless coupling to hearing aids....

  16. ALGEBRA: a computer program that algebraically manipulates finite element output data. [In extended FORTRAN for CDC 7600 or CYBER 76 only

    SciTech Connect

    Richgels, M A; Biffle, J H

    1980-09-01

    ALGEBRA is a program that allows the user to process output data from finite-element analysis codes before they are sent to plotting routines. These data take the form of variable values (stress, strain, and velocity components, etc.) on a tape that is both the output tape from the analyses code and the input tape to ALGEBRA. The ALGEBRA code evaluates functions of these data and writes the function values on an output tape that can be used as input to plotting routines. Convenient input format and error detection capabilities aid the user in providing ALGEBRA with the functions to be evaluated. 1 figure.

  17. Visual Aids for English Teaching

    ERIC Educational Resources Information Center

    Matsuda, Masahira

    1975-01-01

    Techniques for the use of the following visual aids are described: hand gestures, drawing diagrams on the blackboard, real objects, magnetic boards and pictures and charts. The aids help to maintain student interest and bridge the gap between drill and communication. (AG)

  18. AIDS--mémoire.

    PubMed

    Jacobson, L

    1994-08-13

    A czar was born when President Clinton named Kristine M. Gebbie to be his national AIDS policy coordinator. But a year later, under unrelenting fire from AIDS activists, Gebbie resigned. Her departure underscores the trouble that some activists have had shifting from the outsider's game to the insider's.

  19. The Underpinnings of Student Aid.

    ERIC Educational Resources Information Center

    Linsley, Coral B.

    1997-01-01

    Reviews the basic concepts governing student aid funding and the mechanics of delivery, including a review of the development of current federal financial aid programs, the complexities of determining student need, institutional responsibility, and suggested areas for institutional research. Notes that the challenges ahead include strengthening…

  20. [AIDS: faith healers versus medicine].

    PubMed

    Gottingar, V

    1989-09-01

    The majority of AIDS patients in Africa rely on traditional healers to treat their disease rather than on Western medicine. Most western medical treatments currently available are beyond the financial resources of all but the wealthiest Africans, and most African countries lack the means to provide serious medical treatment for AIDS patients. AZT is almost the only drug used on a wide scale against AIDS, but its cost is estimated by the World Health Organization at $7-8000/year for each individual, not counting other treatments and hospital care. AIDS therapies offered by African health services exhaust their already meager health budgets. The money is lacking even to buy condoms to prevent the epidemic from spreading. Hospital hygiene may be poor and diagnostic and therapeutic tools lacking even for those AIDS patients able to be treated by modern medical specialists. Africa lacks the financial, scientific, social, and economic means of combatting AIDS. Some AIDS experts suggest that African governments underestimate the number of seropositive individuals in order to avoid frightening the population and discouraging tourists and investors. In the absence of an effective treatment or vaccine, the only tools to fight AIDS will be raising the awareness of the population to the gravity of the threat, systematic screening of blood donors, sterilization of syringes, and distribution of condoms.