Science.gov

Sample records for compressed work week

  1. My working week: John Innes.

    PubMed

    Innes, John

    2016-07-23

    In the first of a new series of features for Vet Record Careers, John Innes describes a recent working week as referrals director for CVS and a RCVS specialist in small animal orthopaedics. PMID:27450857

  2. Plant Operation: Work Week, Administration

    ERIC Educational Resources Information Center

    Nation's Schools and Colleges, 1975

    1975-01-01

    A four-day work week for maintenance workers in the Jefferson County Public Schools in Lakewood, Colorado, reduces absenteeism and increases productivity; a basic manual for physical plant directors is reviewed. (Author/MLF)

  3. A 4-Day Work Week That Works.

    ERIC Educational Resources Information Center

    Walker, Kenneth; Timmerman, Linda

    1980-01-01

    Describes Navarro College's (Corsicana, TX) program to reduce kilowatt hour consumption through alternative energy sources and energy costs through transition to a four-day/40-hour work week. Presents results of studies of employee performance levels, community response, and the cost effectiveness of the program. Lists benefits for the student,…

  4. 5 CFR 532.513 - Flexible and compressed work schedules.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Flexible and compressed work schedules... REGULATIONS PREVAILING RATE SYSTEMS Premium Pay and Differentials § 532.513 Flexible and compressed work schedules. Federal Wage System employees who are authorized to work flexible and compressed work...

  5. 5 CFR 532.513 - Flexible and compressed work schedules.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Flexible and compressed work schedules... REGULATIONS PREVAILING RATE SYSTEMS Premium Pay and Differentials § 532.513 Flexible and compressed work schedules. Federal Wage System employees who are authorized to work flexible and compressed work...

  6. 5 CFR 532.513 - Flexible and compressed work schedules.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Flexible and compressed work schedules... REGULATIONS PREVAILING RATE SYSTEMS Premium Pay and Differentials § 532.513 Flexible and compressed work schedules. Federal Wage System employees who are authorized to work flexible and compressed work...

  7. 5 CFR 532.513 - Flexible and compressed work schedules.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Flexible and compressed work schedules... REGULATIONS PREVAILING RATE SYSTEMS Premium Pay and Differentials § 532.513 Flexible and compressed work schedules. Federal Wage System employees who are authorized to work flexible and compressed work...

  8. 5 CFR 532.513 - Flexible and compressed work schedules.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Flexible and compressed work schedules... REGULATIONS PREVAILING RATE SYSTEMS Premium Pay and Differentials § 532.513 Flexible and compressed work schedules. Federal Wage System employees who are authorized to work flexible and compressed work...

  9. 2009 Summer 4-Day Work Week Evaluation Report

    ERIC Educational Resources Information Center

    Geneivive, David V.; DeRose, Diego; Ligas, Maria

    2011-01-01

    This report describes the final evaluation of a condensed work schedule, the Summer 2009 4-Day Work Week (S4-DWW), adopted by The School Board of Broward County, Florida. The goal for the program was to close the entire district for 1 day each week to reduce utility costs. Except for a few cases, district schools and offices were closed on Fridays…

  10. Working characteristics of variable intake valve in compressed air engine.

    PubMed

    Yu, Qihui; Shi, Yan; Cai, Maolin

    2014-01-01

    A new camless compressed air engine is proposed, which can make the compressed air energy reasonably distributed. Through analysis of the camless compressed air engine, a mathematical model of the working processes was set up. Using the software MATLAB/Simulink for simulation, the pressure, temperature, and air mass of the cylinder were obtained. In order to verify the accuracy of the mathematical model, the experiments were conducted. Moreover, performance analysis was introduced to design compressed air engine. Results show that, firstly, the simulation results have good consistency with the experimental results. Secondly, under different intake pressures, the highest output power is obtained when the crank speed reaches 500 rpm, which also provides the maximum output torque. Finally, higher energy utilization efficiency can be obtained at the lower speed, intake pressure, and valve duration angle. This research can refer to the design of the camless valve of compressed air engine. PMID:25379536

  11. Working Characteristics of Variable Intake Valve in Compressed Air Engine

    PubMed Central

    Yu, Qihui; Shi, Yan; Cai, Maolin

    2014-01-01

    A new camless compressed air engine is proposed, which can make the compressed air energy reasonably distributed. Through analysis of the camless compressed air engine, a mathematical model of the working processes was set up. Using the software MATLAB/Simulink for simulation, the pressure, temperature, and air mass of the cylinder were obtained. In order to verify the accuracy of the mathematical model, the experiments were conducted. Moreover, performance analysis was introduced to design compressed air engine. Results show that, firstly, the simulation results have good consistency with the experimental results. Secondly, under different intake pressures, the highest output power is obtained when the crank speed reaches 500 rpm, which also provides the maximum output torque. Finally, higher energy utilization efficiency can be obtained at the lower speed, intake pressure, and valve duration angle. This research can refer to the design of the camless valve of compressed air engine. PMID:25379536

  12. Training for fitness: reconsidering the 80-hour work week.

    PubMed

    Caldicott, Catherine V; Holsapple, James W

    2008-01-01

    The medical literature is replete with articles about the Accreditation Council for Graduate Medical Education's 2003 resident duty hour restrictions. Most of these papers describe creative and thoughtful responses to the new system. However, others express concern that the "80-hour work week" could hamper continuity of care and educational activities. Nevertheless, if fatigue impairs resident learning and medical care quality, then work hour restrictions seem worthwhile. We add our voices to the critics' for additional reasons. Data support that fatigue occurs even with reasonable work schedules, and residents do not reliably use time off from work to rest. Regulated work schedules can interfere with adequate rehearsal of the physical and mental stamina required in certain specialties, yet patients have a right to expect their physicians to be trained in the particular demands of those specialties. Similarly, residents have a right to a realistic understanding of authentic clinical practice. Further, while self-sacrifice need not be routine, trainees should feel that occasional self-sacrifice is appropriate and acceptable for a physician. We reject uniform, arbitrary duty hour limits for all specialties. Rather, we propose that a subspecialty-based system can foster the development of the endurance, skills, and reasoning that patients and colleagues expect. PMID:18192772

  13. 5 CFR 610.407 - Premium pay for holiday work for employees on compressed work schedules.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Premium pay for holiday work for employees on compressed work schedules. 610.407 Section 610.407 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS HOURS OF DUTY Flexible and Compressed Work Schedules § 610.407...

  14. 5 CFR 610.407 - Premium pay for holiday work for employees on compressed work schedules.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Premium pay for holiday work for employees on compressed work schedules. 610.407 Section 610.407 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS HOURS OF DUTY Flexible and Compressed Work Schedules § 610.407...

  15. 5 CFR 610.407 - Premium pay for holiday work for employees on compressed work schedules.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Premium pay for holiday work for employees on compressed work schedules. 610.407 Section 610.407 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS HOURS OF DUTY Flexible and Compressed Work Schedules § 610.407...

  16. 5 CFR 610.407 - Premium pay for holiday work for employees on compressed work schedules.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Premium pay for holiday work for employees on compressed work schedules. 610.407 Section 610.407 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS HOURS OF DUTY Flexible and Compressed Work Schedules § 610.407...

  17. 5 CFR 610.407 - Premium pay for holiday work for employees on compressed work schedules.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Premium pay for holiday work for employees on compressed work schedules. 610.407 Section 610.407 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS HOURS OF DUTY Flexible and Compressed Work Schedules § 610.407...

  18. Solid liner compression of working fluid to megabar range

    SciTech Connect

    Degnan, J.H.; Coffey, S.K.; Gale, D.G.

    1997-12-31

    The authors have used 12 megamp, 5 megajoule axial discharges to electromagnetically implode tapered thickness spherical aluminum shells, achieving peak implosion velocities above 20 km/sec inner surface, 10 km/sec thickness averaged. The shell thickness was proportional to the inverse of the square of the cylindrical radius. This causes the ratio of magnetic pressure to shell areal mass density (and spherical acceleration) to be independent of polar angle, so that the spherical shape is nominally maintained during the implosion. The authors have used these implosions to compress hot hydrogen plasmas with initial pressure about 100 atm and initial temperature above 1 eV. The hot hydrogen plasmas were injected beforehand using 1 megamp, 100 kilojoule range co-axial gun discharges through a circular array of vanes to strip away magnetic field. The imploding shell and the compressed hot hydrogen working fluid`s effect on a diagnostic compression target were observed with radiography. Interior magnetic probes and auxiliary shots without working fluid injection were used to confirm that there is no magnetic field interior to the imploding aluminum shell. Thus, diagnostic target compression, which was observed in working fluid compression experiments, was presumably due to the compressed hot hydrogen pressure.

  19. Flux penetration of an aluminum liner during working fluid compression

    SciTech Connect

    Bell, D.E.; Hussey, T.W.

    1995-08-15

    The Phillips Laboratory working fluid experiment is a research effort to study the compression of a hot hydrogen gas using an electromagnetically imploded solid liner. In our experiments, the solid liner is driven by a 5 MJ discharge which Joule heats the aluminum, melting and eventually vaporizing it. This numerical study explores the vaporization and flux penetration of a solid aluminum liner during its implosion. In particular, it considers the effect that flux which has penetrated the liner has on the hot hydrogen working fluid. A study of the dynamics of the solid liner was performed with one-dimensional radiation magnetohydrodynamic simulations, which included a careful treatment of the electrical resistivity near the phase transitions. An analytic snowplow model is developed in order to estimate the minimum working fluid density required to ignore flux penetration through the liner.

  20. Balancing Work and Academics in College: Why Do Students Working 10 to 19 Hours Per Week Excel?

    ERIC Educational Resources Information Center

    Dundes, Lauren; Marx, Jeff

    2007-01-01

    Given that 74% of undergraduates work an average of 25.5 hours per week while going to school, we know surprisingly little about how off-campus employment affects undergraduates and to what extent its impact varies by the number of hours worked. Our survey of undergraduates at a small liberal arts college found that the academic performance of…

  1. 5 CFR 610.406 - Holiday for employees on compressed work schedules.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Holiday for employees on compressed work schedules. 610.406 Section 610.406 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS HOURS OF DUTY Flexible and Compressed Work Schedules § 610.406 Holiday for employees on...

  2. 5 CFR 610.406 - Holiday for employees on compressed work schedules.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Holiday for employees on compressed work schedules. 610.406 Section 610.406 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS HOURS OF DUTY Flexible and Compressed Work Schedules § 610.406 Holiday for employees on...

  3. 5 CFR 610.406 - Holiday for employees on compressed work schedules.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Holiday for employees on compressed work schedules. 610.406 Section 610.406 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS HOURS OF DUTY Flexible and Compressed Work Schedules § 610.406 Holiday for employees on...

  4. 5 CFR 610.406 - Holiday for employees on compressed work schedules.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Holiday for employees on compressed work schedules. 610.406 Section 610.406 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS HOURS OF DUTY Flexible and Compressed Work Schedules § 610.406 Holiday for employees on...

  5. 5 CFR 610.406 - Holiday for employees on compressed work schedules.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Holiday for employees on compressed work schedules. 610.406 Section 610.406 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS HOURS OF DUTY Flexible and Compressed Work Schedules § 610.406 Holiday for employees on...

  6. Target compressions by working fluids driven with solid liner implosions

    NASA Technical Reports Server (NTRS)

    Chiang, P.-R.; Lewis, R. A.; Smith, G. A.; Dailey, J. M.; Chakrabarti, S.; Higman, K. I.; Bell, D.; Degnan, J. H.; Hussey, T. W.; Mullins, B. W.

    1994-01-01

    Compression by a spherical solid liner of a gold target surrounded by a hydrogen plasma is simulated. Two-dimensional simulations that treat only a subset of the physics included in the one-dimensional code were performed in an attempt to assess multidimensional effects. A one-dimensional numerical code has been developed to study the effects of thermal radiation and conduction. Results of pressure, density, and energy deposited for different initial plasma conditions are presented and discussed. Results from both one- and two-dimensional codes show that the average target density at peak compression is 39-43 g/cu cm, using the SHIVA Star facility at 90 kV discharge.

  7. From 40 to 35 Hours: Reduction and Flexibilisation of the Working Week in the Federal Republic of Germany.

    ERIC Educational Resources Information Center

    Bosch, Gerhard

    1990-01-01

    Reviews developments in the shortened work week in the Federal Republic of Germany. Discusses collective agreements and examines the methods used to implement the shorter working week at enterprise level and possible developments in the reunited Germany. (JOW)

  8. Are Canadian general surgery residents ready for the 80-hour work week? A nationwide survey

    PubMed Central

    Sudarshan, Monisha; Hanna, Wael C.; Jamal, Mohammed H.; Nguyen, Lily H.P.; Fraser, Shannon A.

    2012-01-01

    Background The purpose of this study was to describe Canadian general surgery residents’ perceptions regarding potential implementation of work-hour restrictions. Methods An ethics review board–approved, Web-based survey was submitted to all Canadian general surgery residency programs between April and July 2009. Questions evaluated the perceived effects of an 80-hour work week on length of training, operative exposure, learning and lifestyle. We used the Fisher exact test to compare senior and junior residents’ responses. Results Of 360 residents, 158 responded (70 seniors and 88 juniors). Among them, 79% reported working 75–100 hours per week. About 74% of seniors believed that limiting their work hours would decrease their operative exposure; 43% of juniors agreed (p < 0.001). Both seniors and juniors thought limiting their work hours would improve their lifestyle (86% v. 96%, p = 0.12). Overall, 60% of residents did not believe limiting work hours would extend the length of their training. Regarding 24-hour call, 60% of juniors thought it was hazardous to their health; 30% of seniors agreed (p = 0.001). Both senior and junior residents thought abolishing 24-hour call would decrease their operative exposure (84% v. 70%, p = 0.21). Overall, 31% of residents supported abolishing 24-hour call. About 47% of residents (41% seniors, 51% juniors, p = 0.26) agreed with the adoption of the 80-hour work week. Conclusion There is a training-level based dichotomy of opinion among general surgery residents in Canada regarding the perceived effects of work hour restrictions. Both groups have voted against abolishing 24-hour call, and neither group strongly supports the implementation of the 80-hour work week. PMID:22269303

  9. Administrative Task Force on the Four Day Work Week. Final Report.

    ERIC Educational Resources Information Center

    California State Univ., Los Angeles.

    The Administrative Task Force on a 4-day work week at California State University in Los Angeles was charged with the following responsibilities: (1) To make an indepth study of the "literature" of experience of other universities, a survey of staff, faculty, and students if required, and other activities that will result in setting up a list of…

  10. Magnetic flux penetration of an aluminum liner during working fluid compression

    SciTech Connect

    Bell, D.E.; Hussey, T.W.

    1994-12-31

    The Phillips Laboratory WFX program is a research effort to study the adiabatic compression of a hot hydrogen gas using an electromagnetically imploded solid liner. The potential uses for the megabar pressures obtained include antiproton-catalyzed microfission, magnetized target fusion, hypervelocity projectile acceleration, and equation of state studies. This numerical and analytic study explores the vaporization of an aluminum solid liner during its implosion under the influence of a 5.3 MJ capacitor discharge, and the subsequent magnetic flux penetration into the working fluid. If sufficient magnetic flux diffuses through the liner, then the working fluid is compressed by the magnetic flux rather than the liner. This is undesirable since compression by the magnetic flux will cause the onset of a shock wave within the working fluid. A study of the dynamics of the solid liner was performed with both 1-D and 2-D radiation MHD simulations, which included a careful treatment of the electrical conductivity near the phase transitions. A simple analytic model was developed for determining the effect of the flux penetration on the working fluid compression. The results of this model were used to predict the minimum working fluid density required in order to ignore the flux penetration.

  11. [Medical aspects of the environmental sanitation of workplaces in compressed air work in Japan].

    PubMed

    Mano, Y; Shibayama, M

    1987-01-01

    Actual follow-up investigations were made for a period of 5 yr and 10 months since February 1980 on 55 places of caisson and shield work. The maximum bottom pressure in caisson work was 3.6 kg/cm2 (4.6 ATA) and that of shield work was 1.6 kg/cm2. The number of exposures of workers was 23,737 in caisson work and 75,244 in shield work. The items of geomedical measurements were temperature (degrees C), humidity, dust, illumination, noise, oxygen, carbonic acid gas and others. In compressed air work, it is most important to prevent decompression sickness (bends) from the view of occupational health. The incidence of bends has decreased in recent years because of strict control by regulations. Environmental hygiene, however, has seldom been discussed in this field and little geomedical control has been made on compressed air work. In view of this situation, we have, therefore, studied, observed, and measured the hygienic factors of this work during the past five years. This investigation is without doubt the first of its kind in Japan and the areas covered most of the regions where compressed air works have been made in the past. From these results, it can be concluded as follows: The working temperature was controlled, but humidity was too high (nearly 90%). Illumination was insufficient. Dust was a problem, but high humidity played an important role in decreasing the volume. The environment was noisy. It is therefore natural that environmental studies should be continued and hygienic consideration be further emphasized in compressed air work. PMID:3613254

  12. Compressed-air work is entering the field of high pressures.

    PubMed

    Le Péchon, J Cl; Gourdon, G

    2010-01-01

    Since 1850, compressed-air work has been used to prevent shafts or tunnels under construction from flooding. Until the 1980s, workers were digging in compressed-air environments. Since the introduction of tunnel boring machines (TBMs), very little digging under pressure is needed. However, the wearing out of cutter-head tools requires inspection and repair. Compressed-air workers enter the pressurized working chamber only occasionally to perform such repairs. Pressures between 3.5 and 4.5 bar, that stand outside a reasonable range for air breathing, were reached by 2002. Offshore deep diving technology had to be adapted to TBM work. Several sites have used mixed gases: in Japan for deep shaft sinking (4.8 bar), in The Netherlands at Western Scheldt Tunnels (6.9 bar), in Russia for St. Petersburg Metro (5.8 bar) and in the United States at Seattle (5.8 bar). Several tunnel projects are in progress that may involve higher pressures: Hallandsås (Sweden) interventions in heliox saturation up to 13 bar, and Lake Mead (U.S.) interventions to about 12 bar (2010). Research on TBMs and grouting technologies tries to reduce the requirements for hyperbaric works. Adapted international rules, expertise and services for saturation work, shuttles and trained personnel matching industrial requirements are the challenges. PMID:20737925

  13. How to increase the burden on trauma centers: implement the 80-hour work week.

    PubMed

    Schroeppel, Thomas J; Sharpe, John P; Magnotti, Louis J; Weinberg, Jordan A; Croce, Martin A; Fabian, Timothy C

    2014-07-01

    The 80-hour week was implemented in 2003 to improve outcomes and limit errors. We hypothesize that there has been no change in outcomes postimplementation of the restrictions. Outcomes were queried from the trauma registry from 1997 to 2002 (PRE) and 2004 to 2009 (POST). Primary outcomes were mortality, intensive care unit length of stay (ICU LOS), and length of stay (LOS). Patients were stratified based on demographics, blood pressure, heart rate, and injury severity (Injury Severity Score, Glasgow Coma Score, base deficit). Outcomes were then compared PRE with POST. A total of 41,770 patients were admitted during the study period. The mean age was 38 years with most being male (73%) and blunt mechanism (78%). Although patients admitted in the POST period had a slightly higher blood pressure, they were older and had higher injury severity. ICU LOS, LOS, self-pay, and mortality were higher in the POST period. After adjusted analysis, admission in the POST period was no longer a predictor of mortality (odds ratio, 1.02; confidence interval, 0.92 to 1.14). Whereas patients were more slightly more injured in the POST period, the adjusted analysis shows no difference in mortality and both a longer LOS and ICU LOS. Whether the increase is the result of more severe injury in the POST period or less efficient disposition remains to be elucidated. This study adds to the mounting evidence that the implementation of the limits on work hours does not lead to better outcomes. PMID:24987896

  14. Sleep and health in oil rig workers--before and after a two week work period offshore.

    PubMed

    Waage, Siri; Pallesen, Ståle; Moen, Bente Elisabeth; Bjorvatn, Bjørn

    2013-01-01

    This study compared subjective sleep and subjective health complaints among Norwegian oil rig workers, before and after a two week work period. The study also compared differences between two different work schedules. The workers worked either two weeks of day shift (n=90) or two weeks of a swing shift schedule (n=93), involving one week of night shifts, immediately followed by one week of day shifts. Overall, the workers reported significantly poorer sleep quality and more complaints of insomnia at the end compared to the start of the work period. However, there was no significant difference in terms of subjective health complaints. Furthermore, there were no clear differences in changes in sleep quality, insomnia or subjective health complaints during the work period between day- and swing shift workers. However, at the end of the work period a higher proportion of insomniacs were seen among swing shift workers compared with day workers. To conclude, sleep quality and complaints of insomnia became worse during the work period. However, there were few differences in changes in terms of sleep or subjective health complaints between day- and swing shift, suggesting that 12 h day shift affected sleep and health similarly to the schedule involving night work. PMID:23196391

  15. On the work distribution for the adiabatic compression of a diluteclassical gas

    SciTech Connect

    Crooks, Gavin E.; Jarzynski, Christopher

    2006-02-23

    We consider the adiabatic and quasi-static compression of adilute classical gas, confined in a piston and initially equilibratedwith a heat bath. We find that the work performed during this process isdescribed statistically by a gamma distribution. We use this result toshow that the model satisfies the non-equilibrium work and fluctuationtheorems, but not the fluctation-dissipation relation. We discuss therare but dominant realizations that contribute most to the exponentialaverage of the work, and relate our results to potentially universal workdistributions.

  16. Employment and the Reduction of the Work Week: A Comparison of Seven European Macro-economic Models.

    ERIC Educational Resources Information Center

    van Ginneken, Wouter

    1984-01-01

    Analyzes the impact of a reduced work week on employment, productivity, wages, investment, economic growth, inflation, and government deficits. Concludes that reducing working hours would have greater effect if accompanied by wage reductions and limitation of overtime, but would not affect underlying causes of unemployment. (SK)

  17. Initial Learning in Mainstreaming Project: Off Base 10, Working with Years, Months, Weeks, Days.

    ERIC Educational Resources Information Center

    Tipton, Fern S.; Kingston, Neldon

    Developed by the Initial Learning in Mainstreaming Project, the manual presents an instructional program to teach mainstreamed handicapped elementary school students how to tell and compute time in terms of years, months, weeks, and days. In addition to the basic time facts, the lessons cover carrying or borrowing with off-base-10 time facts, and…

  18. Weekly working hours for Norwegian hospital doctors since 1994 with special attention to postgraduate training, work–home balance and the European Working Time Directive: a panel study

    PubMed Central

    Rosta, Judith; Aasland, Olaf G

    2014-01-01

    Objectives To examine the weekly working hours of Norwegian hospital doctors from 1994 to 2012 with special emphasis on the quality of postgraduate training and work–home balance, and in relation to the requirements of the European Working Time Directive (EWTD). Design Panel study based on postal questionnaires. Setting Norway. Participants Unbalanced cohort of 1300–1600 doctors in 1994, 1995, 1996, 1997, 2000, 2002, 2004, 2006, 2008, 2010 and 2012. Outcome measures Self-reported total weekly working hours and whether 45 weekly working hours are too short, sufficient, or too long to meet the quality requirements of obligatory postgraduate training for junior doctors. Results From 1994 to 2012, the number of weekly working hours was stable for senior (46–47 h) and junior (45–46 h) hospital doctors. In 2012, significantly more senior (27–35%) than junior (11–20%) doctors reported suboptimal work–home balance, defined as working more than 48 h a week. The majority perceived the present situation with an average of 45 h per week for juniors as sufficient for obligatory postgraduate specialist training, but doctors of higher age (OR 1.04, 95% CI 1.01 to 1.08), senior doctors (1.07, 1.04 to 1.11) and doctors working in surgical specialties (OR 1 vs laboratory medicine 0.03, 0.01 to 0.25, internal medicine 0.31, 0.17 to 0.58, psychiatry 0.12, 0.04 to 0.36, paediatrics 0.36, 0.12 to 1.07, anaesthesiology 0.08, 0.02 to 0.39, gynaecology 0.07, 0.01 to 0.56 and others 0.39, 0.04 to 3.56) were more likely to want the work-week to be longer. Conclusions The weekly working hours of Norwegian hospital doctors were always below the EWTD requirements. A significant growth of hospital doctor density over the past two decades, national regulations and cultural values might be important factors. Specialty differences in perception of sufficient training time may call for more flexibility in working time regulations. PMID:25311038

  19. Working multiple jobs over a day or a week: Short-term effects on sleep duration.

    PubMed

    Marucci-Wellman, Helen R; Lombardi, David A; Willetts, Joanna L

    2016-01-01

    Approximately 10% of the employed population in the United States works in multiple jobs. They are more likely to work long hours and in nonstandard work schedules, factors known to impact sleep duration and quality, and increase the risk of injury. In this study we used multivariate regression models to compare the duration of sleep in a 24-hour period between workers working in multiple jobs (MJHs) with single job holders (SJHs) controlling for other work schedule and demographic factors. We used data from the Bureau of Labor Statistics US American Time Use Survey (ATUS) pooled over a 9-year period (2003-2011). We found that MJHs had significantly reduced sleep duration compared with SJHs due to a number of independent factors, such as working longer hours and more often late at night. Male MJHs, working in their primary job or more than one job on the diary day, also had significantly shorter sleep durations (up to 40 minutes less on a weekend day) than male SJHs, even after controlling for all other factors. Therefore, duration of work hours, time of day working and duration of travel for work may not be the only factors to consider when understanding if male MJHs are able to fit in enough recuperative rest from their busy schedule. Work at night had the greatest impact on sleep duration for females, reducing sleep time by almost an hour compared with females who did not work at night. We also hypothesize that the high frequency or fragmentation of non-leisure activities (e.g. work and travel for work) throughout the day and between jobs may have an additional impact on the duration and quality of sleep for MJHs. PMID:27092404

  20. Working multiple jobs over a day or a week: Short-term effects on sleep duration

    PubMed Central

    Marucci-Wellman, Helen R.; Lombardi, David A.; Willetts, Joanna L.

    2016-01-01

    ABSTRACT Approximately 10% of the employed population in the United States works in multiple jobs. They are more likely to work long hours and in nonstandard work schedules, factors known to impact sleep duration and quality, and increase the risk of injury. In this study we used multivariate regression models to compare the duration of sleep in a 24-hour period between workers working in multiple jobs (MJHs) with single job holders (SJHs) controlling for other work schedule and demographic factors. We used data from the Bureau of Labor Statistics US American Time Use Survey (ATUS) pooled over a 9-year period (2003–2011). We found that MJHs had significantly reduced sleep duration compared with SJHs due to a number of independent factors, such as working longer hours and more often late at night. Male MJHs, working in their primary job or more than one job on the diary day, also had significantly shorter sleep durations (up to 40 minutes less on a weekend day) than male SJHs, even after controlling for all other factors. Therefore, duration of work hours, time of day working and duration of travel for work may not be the only factors to consider when understanding if male MJHs are able to fit in enough recuperative rest from their busy schedule. Work at night had the greatest impact on sleep duration for females, reducing sleep time by almost an hour compared with females who did not work at night. We also hypothesize that the high frequency or fragmentation of non-leisure activities (e.g. work and travel for work) throughout the day and between jobs may have an additional impact on the duration and quality of sleep for MJHs. PMID:27092404

  1. The Time Divide in Cross-National Perspective: The Work Week, Education and Institutions that Matter

    ERIC Educational Resources Information Center

    Frase, Peter; Gornick, Janet C.

    2013-01-01

    Prior empirical studies have found that American workers report longer hours than do workers in other highly industrialized countries, and that the highly educated report the longest hours relative to other educational levels. This paper analyzes disparities in working hours by education levels in 17 high- and middle-income countries to assess…

  2. 29 CFR 794.142 - Special compensation when overtime in excess of 12 daily or 56 weekly hours is worked in the...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... by section 7(b)(3) for hours in excess of 40, and works 60 hours in a workweek in which 10 of his... compensation in the amount of $80 for 40 hours of work and in the amount of $48 for the 20 additional hours... employee in a workweek when his hours worked do not exceed 56 in the week; and for all weekly...

  3. Self-Reported Recovery from 2-Week 12-Hour Shift Work Schedules: A 14-Day Follow-Up

    PubMed Central

    Merkus, Suzanne L.; Holte, Kari Anne; Huysmans, Maaike A.; van de Ven, Peter M.; van Mechelen, Willem; van der Beek, Allard J.

    2015-01-01

    Background Recovery from fatigue is important in maintaining night workers' health. This study compared the course of self-reported recovery after 2-week 12-hour schedules consisting of either night shifts or swing shifts (i.e., 7 night shifts followed by 7 day shifts) to such schedules consisting of only day work. Methods Sixty-one male offshore employees—20 night workers, 16 swing shift workers, and 25 day workers—rated six questions on fatigue (sleep quality, feeling rested, physical and mental fatigue, and energy levels; scale 1–11) for 14 days after an offshore tour. After the two night-work schedules, differences on the 1st day (main effects) and differences during the follow-up (interaction effects) were compared to day work with generalized estimating equations analysis. Results After adjustment for confounders, significant main effects were found for sleep quality for night workers (1.41, 95% confidence interval 1.05–1.89) and swing shift workers (1.42, 95% confidence interval 1.03–1.94) when compared to day workers; their interaction terms were not statistically significant. For the remaining fatigue outcomes, no statistically significant main or interaction effects were found. Conclusion After 2-week 12-hour night and swing shifts, only the course for sleep quality differed from that of day work. Sleep quality was poorer for night and swing shift workers on the 1st day off and remained poorer for the 14-day follow-up. This showed that while working at night had no effect on feeling rested, tiredness, and energy levels, it had a relatively long-lasting effect on sleep quality. PMID:26929834

  4. An old integration scheme for compressible flows revisited, refurbished and put to work

    NASA Technical Reports Server (NTRS)

    Moretti, G.

    1978-01-01

    A scheme for integrating the Euler equations of compressible flow in any hyperbolic case is presented. The scheme relies on the concept of characteristics but is strictly a finite difference scheme. Improvements in accuracy and physical consistence due to the scheme are discussed and results of its application to complex flows are shown.

  5. Leptin level lowers in proportion to the amount of aerobic work after four weeks of training in obesity.

    PubMed

    Salvadori, A; Fanari, P; Brunani, A; Marzullo, P; Codecasa, F; Tovaglieri, I; Cornacchia, M; Palmulli, P; Longhini, E

    2015-03-01

    Leptin values are higher in obesity. Physical exercise reduces fat mass (FM) and decreases leptin levels. Intensity of physical training seems to play a role in reducing circulating leptin. In 16 obese subjects (8 men and 8 women, age 38.6±3.9 years, BMI 35.9±1.8 kg/m(2)), leptin was sampled before and after 4 weeks of controlled training. Eight subjects (4 men and 4 women) performed an aerobic training schedule (Group A), the remainders an aerobic training program with a bout of work beyond the anaerobic threshold (AT) (Group B). Training determined a reduction in leptin levels in both groups, which was significant in Group A (12.2 vs. 27.8 μg/l, p<0.05), even when related to the change in FM (0.372 vs. 0.762 μg/l/kg, p<0.05). FM decreased significantly in Group B when compared to Group A (-7.4 vs. -2.6 kg, respectively, p<0.001). While in Group A the slight loss of FM was aggregated to a significant decrease in leptin levels, the opposite occurred in Group B. In Group A, leptin lowering was proportional to the amount of total work performed (p<0.001, R(2)=0.89). In obesity, a reduction is observed in leptin levels after short-term training, which is seemingly dissociated from concomitant decrease of FM. Aerobic training alone appears to be linked to a greater leptin reduction, which is well correlated with the amount of work performed. PMID:25502942

  6. 45 CFR 286.90 - How many hours per week must an adult or minor head-of-household participate in work-related...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 2 2010-10-01 2010-10-01 false How many hours per week must an adult or minor head-of-household participate in work-related activities to count in the numerator of the work participation rate? 286.90 Section 286.90 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE...

  7. 45 CFR 286.90 - How many hours per week must an adult or minor head-of-household participate in work-related...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 2 2012-10-01 2012-10-01 false How many hours per week must an adult or minor... must an adult or minor head-of-household participate in work-related activities to count in the numerator of the work participation rate? During the month, an adult or minor head-of-household...

  8. 45 CFR 286.90 - How many hours per week must an adult or minor head-of-household participate in work-related...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 2 2011-10-01 2011-10-01 false How many hours per week must an adult or minor... must an adult or minor head-of-household participate in work-related activities to count in the numerator of the work participation rate? During the month, an adult or minor head-of-household...

  9. 45 CFR 286.90 - How many hours per week must an adult or minor head-of-household participate in work-related...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 2 2013-10-01 2012-10-01 true How many hours per week must an adult or minor head... must an adult or minor head-of-household participate in work-related activities to count in the numerator of the work participation rate? During the month, an adult or minor head-of-household...

  10. 45 CFR 286.90 - How many hours per week must an adult or minor head-of-household participate in work-related...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 2 2014-10-01 2012-10-01 true How many hours per week must an adult or minor head... must an adult or minor head-of-household participate in work-related activities to count in the numerator of the work participation rate? During the month, an adult or minor head-of-household...

  11. Examining the Transition to a Four-Day School Week and Investigating Post-Change Faculty/Staff Work-Life Balance: A Community College Case Study

    ERIC Educational Resources Information Center

    Cardinale, Nelly

    2013-01-01

    This single descriptive embedded case study examined the process of implementing a four-day work/school week at a community college and investigated post-change faculty/staff work-life balance. All of the students attending this college live at home. The change was implemented due to state funding shortfalls, increasing college utility expenses…

  12. A Week in the Life of Full-Time Office Workers: Work Day and Weekend Light Exposure in Summer and Winter

    PubMed Central

    Crowley, Stephanie J.; Molina, Thomas A.; Burgess, Helen J.

    2014-01-01

    Little is known about the light exposure in full-time office workers, who spend much of their workdays indoors. We examined the 24-hour light exposure patterns of 14 full-time office workers during a week in summer, and assessed their dim light melatonin onset (DLMO, a marker of circadian timing) at the end of the working week. Six workers repeated the study in winter. Season had little impact on the workers' schedules, as the timing of sleep, commute, and work did not vary by more than 30 minutes in the summer and winter. In both seasons, workers received significantly more morning light on workdays than weekends, due to earlier wake times and the morning commute. Evening light in the two hours before bedtime was consistently dim. The timing of the DLMO did not vary between season, and by the end of the working week, the workers slept at a normal circadian phase. PMID:25172304

  13. Update: These School Systems Swear by the Four-Day School Week because Students Work Harder and Face Fewer Distractions.

    ERIC Educational Resources Information Center

    Blankenship, Ted

    1984-01-01

    Dexter, Kansas, uses a four-day school week that is improving classroom instruction and cutting energy bills. There is evidence that four-day schedules improve student achievement, increase attendance, allow more class time, raise teacher morale, and provide more staff development time. (MD)

  14. Human Structure in Six and One-Half Weeks: One Approach to Providing Foundational Anatomical Competency in an Era of Compressed Medical School Anatomy Curricula

    ERIC Educational Resources Information Center

    Halliday, Nancy; O'Donoghue, Daniel; Klump, Kathryn E.; Thompson, Britta

    2015-01-01

    The University of Oklahoma College of Medicine reduced gross anatomy from a full semester, 130-hour course to a six and one-half week, 105-hour course as part of a new integrated systems-based pre-clinical curriculum. In addition to the reduction in contact hours, content from embryology, histology, and radiology were added into the course. The…

  15. A Poll about Children and Weight: Crunch Time during the American Work and School Week--3 P.M. to Bed. Summary

    ERIC Educational Resources Information Center

    Robert Wood Johnson Foundation, 2013

    2013-01-01

    Childhood obesity is a major public health challenge today, with complex roots interwoven into nearly every facet of American life. This poll addresses one narrow slice of this web: the challenges that families face during the "crunch time" of the work and school week, between 3 p.m. and the time children go to bed. Compared to the school day,…

  16. A Poll about Children and Weight: Crunch Time during the American Work and School Week--3 P.M. to Bed

    ERIC Educational Resources Information Center

    Robert Wood Johnson Foundation, 2013

    2013-01-01

    Childhood obesity is a major public health challenge today, with complex roots interwoven into nearly every facet of American life. This poll addresses one narrow slice of this web: the challenges that families face during the "crunch time" of the work and school week, between 3 pm and the time children go to bed. Compared to the school day, this…

  17. 29 CFR 794.141 - Workweeks when hours worked do not exceed 12 in any day or 56 in the week; compensation...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... hours worked do not exceed 12 in any day or 56 in the week; compensation requirements. (a) The overtime pay exemption provided by section 7(b)(3) is “limited to 12 hours a day and 56 hours a week” in any... previously discussed in this part in any workweek when his hours of work do not exceed 12 in any day or 56...

  18. Compression in Visual Working Memory: Using Statistical Regularities to Form More Efficient Memory Representations

    ERIC Educational Resources Information Center

    Brady, Timothy F.; Konkle, Talia; Alvarez, George A.

    2009-01-01

    The information that individuals can hold in working memory is quite limited, but researchers have typically studied this capacity using simple objects or letter strings with no associations between them. However, in the real world there are strong associations and regularities in the input. In an information theoretic sense, regularities…

  19. The dynamical mechanical properties of tungsten under compression at working temperature range of divertors

    NASA Astrophysics Data System (ADS)

    Zhu, C. C.; Song, Y. T.; Peng, X. B.; Wei, Y. P.; Mao, X.; Li, W. X.; Qian, X. Y.

    2016-02-01

    In the divertor structure of ITER and EAST with mono-block module, tungsten plays not only a role of armor material but also a role of structural material, because electromagnetic (EM) impact will be exerted on tungsten components in VDEs or CQ. The EM loads can reach to 100 MN, which would cause high strain rates. In addition, directly exposed to high-temperature plasma, the temperature regime of divertor components is complex. Aiming at studying dynamical response of tungsten divertors under EM loads, an experiment on tungsten employed in EAST divertors was performed using a Kolsky bar system. The testing strain rates and temperatures is derived from actual working conditions, which makes the constitutive equation concluded by using John-Cook model and testing data very accurate and practical. The work would give a guidance to estimate the dynamical response, fatigue life and damage evolution of tungsten divertor components under EM impact loads.

  20. Staying engaged during the week: the effect of off-job activities on next day work engagement.

    PubMed

    ten Brummelhuis, Lieke L; Bakker, Arnold B

    2012-10-01

    Although studies on employee recovery accumulate at a stunning pace, the commonly used theory (Effort-Recovery model) that explains how recovery occurs has not been explicitly tested. We aimed to unravel the recovery process by examining whether off-job activities enhance next morning vigor to the extent that they enable employees to relax and detach from work. In addition, we investigated whether adequate recovery also helps employees to work with more enthusiasm and vigor on the next workday. On five consecutive days, a total of 74 employees (356 data points) reported the hours they spent on various off-job activities, their feelings of psychological detachment, and feelings of relaxation before going to sleep. Feelings of vigor were reported on the next morning, and day-levels of work engagement were reported after work. As predicted, leisure activities (social, low-effort, and physical activities) increased next morning vigor through enhanced psychological detachment and relaxation. High-duty off-job activities (work and household tasks) reduced vigor because these activities diminished psychological detachment and relaxation. Moreover, off-job activities significantly affected next day work engagement. Our results support the assumption that recovery occurs when employees engage in off-job activities that allow for relaxation and psychological detachment. The findings also underscore the significance of recovery after work: Adequate recovery not only enhances vigor in the morning, but also helps employees to stay engaged during the next workday. PMID:22799771

  1. Human structure in six and one-half weeks: one approach to providing foundational anatomical competency in an era of compressed medical school anatomy curricula.

    PubMed

    Halliday, Nancy; O'Donoghue, Daniel; Klump, Kathryn E; Thompson, Britta

    2015-01-01

    The University of Oklahoma College of Medicine reduced gross anatomy from a full semester, 130-hour course to a six and one-half week, 105-hour course as part of a new integrated systems-based pre-clinical curriculum. In addition to the reduction in contact hours, content from embryology, histology, and radiology were added into the course. The new curriculum incorporated best practices in the area of regular assessments, feedback, clinical application, multiple teaching modalities, and professionalism. A comparison of the components of the traditional and integrated curriculum, along with end of course evaluations and student performance revealed that the new curriculum was just as effective, if not more effective. This article also provides important lessons learned. PMID:24996159

  2. Human Structure in Six and One-Half Weeks: One Approach to Providing Foundational Anatomical Competency in an Era of Compressed Medical School Anatomy curricula

    PubMed Central

    Halliday, Nancy; O'Donoghue, Daniel; Klump, Kathryn E; Thompson, Britta

    2015-01-01

    The University of Oklahoma College of Medicine reduced gross anatomy from a full semester, 130-hour course to a six and one-half week, 105-hour course as part of a new integrated systems-based pre-clinical curriculum. In addition to the reduction in contact hours, content from embryology, histology, and radiology were added into the course. The new curriculum incorporated best practices in the area of regular assessments, feedback, clinical application, multiple teaching modalities, and professionalism. A comparison of the components of the traditional and integrated curriculum, along with end of course evaluations and student performance revealed that the new curriculum was just as effective, if not more effective. This article also provides important lessons learned. Anat Sci Educ 8: 149–157. © 2014 The Authors. Published by Wiley Periodicals, Inc. on behalf of the American Association of Anatomists. PMID:24996159

  3. Working Hours Flexibility. Background Paper No. 30.

    ERIC Educational Resources Information Center

    Staines, Graham L.

    Flexible work schedules offer the promise of a low-cost option for helping people manage work and family responsibilities. Alternative work schedules include part-time work, job sharing, work sharing, shiftwork, compressed work week, flexitime, and flexiplace. Flexitime is the most prevalent full-time flexible schedule and is second in prevalence…

  4. The relationship between low back pain and leisure time physical activity in a working population of cleaners - a study with weekly follow-ups for 1 year

    PubMed Central

    2012-01-01

    LBP in the following 4 weeks. Documentation of LTPA recommendations for acute LBP in working populations is still needed. PMID:22356733

  5. Ten weeks of physical-cognitive-mindfulness training reduces fear-avoidance beliefs about work-related activity: Randomized controlled trial.

    PubMed

    Jay, Kenneth; Brandt, Mikkel; Jakobsen, Markus Due; Sundstrup, Emil; Berthelsen, Kasper Gymoese; Schraefel, Mc; Sjøgaard, Gisela; Andersen, Lars L

    2016-08-01

    People with chronic musculoskeletal pain often experience pain-related fear of movement and avoidance behavior. The Fear-Avoidance model proposes a possible mechanism at least partly explaining the development and maintenance of chronic pain. People who interpret pain during movement as being potentially harmful to the organism may initiate a vicious behavioral cycle by generating pain-related fear of movement accompanied by avoidance behavior and hyper-vigilance.This study investigates whether an individually adapted multifactorial approach comprised of biopsychosocial elements, with a focus on physical exercise, mindfulness, and education on pain and behavior, can decrease work-related fear-avoidance beliefs.As part of a large scale 10-week worksite randomized controlled intervention trial focusing on company initiatives to combat work-related musculoskeletal pain and stress, we evaluated fear-avoidance behavior in 112 female laboratory technicians with chronic neck, shoulder, upper back, lower back, elbow, and hand/wrist pain using the Fear-Avoidance Beliefs Questionnaire at baseline, before group allocation, and again at the post intervention follow-up 10 weeks later.A significant group by time interaction was observed (P < 0.05) for work-related fear-avoidance beliefs. The between-group difference at follow-up was -2.2 (-4.0 to -0.5), corresponding to a small to medium effect size (Cohen's d = 0.30).Our study shows that work-related, but not leisure time activity-related, fear-avoidance beliefs, as assessed by the Fear-avoidance Beliefs Questionnaire, can be significantly reduced by 10 weeks of physical-cognitive-mindfulness training in female laboratory technicians with chronic pain. PMID:27559939

  6. Chronic (3-Weeks) Treatment of Estrogen (17β-Estradiol) Enhances Working and Reference Memory in Ovariectomized Rats: Role of Acetylcholine.

    PubMed

    Uzum, Gulay; Bahcekapili, Nesrin; Baltaci, Abdulkerim Kasim; Mogulkoc, Rasim; Ziylan, Yusuf Ziya

    2016-06-01

    Recently there has been a growing interest in the effects of estrogen on cognitive functions. In this study, we aimed to examine 17β-estradiol treatment on working and reference memory in ovariectomized rats. We also examined the changes in the acetylcholine (ACh) levels in the brain areas associated with learning and memory. The study was performed on Sprague-Dawley type 3-month-old female rats. The rats were divided into four groups as control, ovariectomy (OVX), and OVX and estrogen treatment (10 µg/day i.p. 17β-estradiol) groups for 3 (OVX + E3) and 21 days OVX + E21). The rats were trained on eight arm radial maze task with eight arms baited to assess spatial memory, in addition four arms baited to assess both working and reference memory performances. The electron microscope images of the ACh vesicles in the frontal cortex, temporal cortex and hippocampus areas of the brain which are important regions for learning and memory were screened. Results showed that long term 17β-estradiol treatment has positive effects on both reference memory and working memory and that ACh vesicles increased in the examined brain areas, especially in hippocampus. Our results suggest that 3 weeks 17β-estradiol treatment may have an ameliorative effect on the memory through the central cholinergic system. PMID:26879199

  7. Forgiveness Week.

    ERIC Educational Resources Information Center

    Milner, Art

    1984-01-01

    Carefully orchestrated public relations and publicity campaign at Free Library of Philadelphia motivated an estimated 35,000 patrons to return almost 160,000 overdues during "no fines" week. Coverage by radio stations, newspapers, and television aided recovery of materials including rare 1910 score of a Rachmaninoff symphony which was 31 years…

  8. Project Week at Yeovil.

    ERIC Educational Resources Information Center

    Gadd, K. F.

    1979-01-01

    This article describes an approach to science teaching in which secondary school students and faculty members lived and worked together for a week at Yeovil College, concentrating on science project work. The projects investigated during this time are briefly described. (GA)

  9. The Effects of the Compressed Workweek: A Review of the Evidence.

    ERIC Educational Resources Information Center

    Dawkins, Peter; Tulsi, Narmon

    1990-01-01

    A literature review showed substantial growth in the use of compressed work weeks. Employees benefited from increased leisure but suffered from increased fatigue and work disruption. Organizations might experience enhanced morale and less absenteeism as well as work coordination and communication problems. (SK)

  10. Lossy Text Compression Techniques

    NASA Astrophysics Data System (ADS)

    Palaniappan, Venka; Latifi, Shahram

    Most text documents contain a large amount of redundancy. Data compression can be used to minimize this redundancy and increase transmission efficiency or save storage space. Several text compression algorithms have been introduced for lossless text compression used in critical application areas. For non-critical applications, we could use lossy text compression to improve compression efficiency. In this paper, we propose three different source models for character-based lossy text compression: Dropped Vowels (DOV), Letter Mapping (LMP), and Replacement of Characters (ROC). The working principles and transformation methods associated with these methods are presented. Compression ratios obtained are included and compared. Comparisons of performance with those of the Huffman Coding and Arithmetic Coding algorithm are also made. Finally, some ideas for further improving the performance already obtained are proposed.

  11. Collaborative work on evaluation of ovarian toxicity. 4) Two- or four-week repeated dose study of 4-vinylcyclohexene diepoxide in female rats.

    PubMed

    Ito, Atsushi; Mafune, Naomi; Kimura, Takashi

    2009-01-01

    To determine the optimal administration period for evaluation of ovarian toxicity of 4-vinylcyclohexene diepoxide (VCD), VCD was intraperitoneally administered to female Sprague-Dawley rats at 0 (Control), 5, 20 and 80 mg/kg once a day for 2 or 4 weeks (2- or 4-week study). To identify small follicles, serial sections of the ovaries were stained with routine hematoxylin and eosin (HE) and proliferating cell nuclear antigen (PCNA) immunohistochemistry. In the 4-week study, decrease in small follicles was observed in the ovaries at 20 and 80 mg/kg. In the 2-week study, the same change was also observed at 80 mg/kg. Identification of small follicles using PCNA-stained slides was easier than that using HE-stained slides. In conclusion, histopathological findings in the ovaries are important for evaluation of female reproductive toxicity of VCD, and ovarian toxicity of VCD can be detected by administration for 2 weeks at an appropriate dose level. Furthermore, PCNA immunohistochemistry is effective for evaluation of small follicle destruction in chemical-induced ovarian toxicity. PMID:19265289

  12. Doppler ultrasound surveillance in deep tunneling compressed-air work with Trimix breathing: bounce dive technique compared to saturation-excursion technique.

    PubMed

    Vellinga, T P van Rees; Sterk, W; de Boer, A G E M; van der Beek, A J; Verhoeven, A C; van Dijk, F J H

    2008-01-01

    The Western Scheldt Tunneling Project in The Netherlands provided a unique opportunity to evaluate two deep-diving techniques with Doppler ultrasound surveillance. Divers used the bounce diving techniques for repair and maintenance of the TBM. The tunnel boring machine jammed at its deepest depth. As a result the work time was not sufficient. The saturation diving technique was developed and permitted longer work time at great depth. Thirty-one divers were involved in this project. Twenty-three divers were examined using Doppler ultrasound. Data analysis addressed 52 exposures to Trimix at 4.6-4.8 bar gauge using the bounce technique and 354 exposures to Trimix at 4.0-6.9 bar gauge on saturation excursions. No decompression incidents occurred with either technique during the described phase of the project. Doppler ultrasound revealed that the bubble loads assessed in both techniques were generally low. We find out, that despite longer working hours, shorter decompression times and larger physical workloads, the saturation-excursion technique was associated with significant lower bubble grades than in the bounce technique using Doppler Ultrasound. We conclude that the saturation-excursion technique with Trimix is a good option for deep and long exposures in caisson work. The Doppler technique proved valuable, and it should be incorporated in future compressed-air work. PMID:19175196

  13. Collaborative work on evaluation of ovarian toxicity. 6) Two- or four-week repeated-dose studies and fertility study of cisplatin in female rats.

    PubMed

    Nozaki, Yusuke; Furubo, Eiko; Matsuno, Takayuki; Fukui, Rie; Kizawa, Kazuo; Kozaki, Tsukasa; Sanzen, Takahiro

    2009-01-01

    The main aim of the present study is to determine the optimal administration period of cisplatin with regards to its toxic effects on ovarian morphology in the repeated-dose toxicity study. Cisplatin was administered to female SD rats intraperitoneally once daily at dose levels of 0.25, 0.5, 1.0 and 2.0 mg/kg for 2 weeks, or at dose levels of 0.125, 0.25 and 0.5 mg/kg for 4 weeks in the repeated-dose toxicity study. In the female fertility study, 0.25, 0.5 and 1.0 mg/kg of cisplatin were administered in the same manner from 14 days prior to mating to Day 7 of gestation. In the repeated-dose toxicity study, a decrease in large follicle, an increase in atresia of medium and large follicles, and/or a decrease in currently formed corpus luteum were observed in animals receiving 1.0 and 2.0 mg/kg for 2 weeks, and decreases in small and/or large follicles and an increase in atresia of large follicle were observed in animals receiving 0.25 and 0.5 mg/kg for 4 weeks on the histopathological examination of the ovaries. In the female fertility study, the copulation and fertility indices in the animals receiving 1.0 mg/kg tended to be lower than those in the control animals. In conclusion, histopathological changes in the ovary that were attributable to cisplatin dosing were detected by detailed observation of the ovary in the 2-week study; and therefore, a 2-week administration period is sufficient to evaluate the ovarian toxicity of cisplatin. PMID:19265292

  14. How Many Hours per Week Are Full-Time Community College Counselors Expected to Work? Evidence Indicates That in California No Uniform Load Exists.

    ERIC Educational Resources Information Center

    Kester, Donald L.

    The purpose of this study was to discover the workload policy for full-time counselors at each California community college and to compare them to see what variability existed. The response rate to questionnaires sent to all California community colleges was 79 per cent. Workloads were found to range from 15 to 40 hours per week. It is believed…

  15. Work.

    ERIC Educational Resources Information Center

    Haines, Annette M.

    2003-01-01

    Draws upon Maria Montessori's writings to examine work as a universal human tendency throughout life. Discusses the work of adaptation of the infant, work of "psycho-muscular organism" for the preschooler, work of the imagination for the elementary child, community work of the adolescent, and work of the adult. Asserts that Montessorians' role is…

  16. Parametric and working fluid analysis of a combined organic Rankine-vapor compression refrigeration system activated by low-grade thermal energy.

    PubMed

    Saleh, B

    2016-09-01

    The potential use of many common hydrofluorocarbons and hydrocarbons as well as new hydrofluoroolefins, i.e. R1234yf and R1234ze(E) working fluids for a combined organic Rankine cycle and vapor compression refrigeration (ORC-VCR) system activated by low-grade thermal energy is evaluated. The basic ORC operates between 80 and 40 °C typical for low-grade thermal energy power plants while the basic VCR cycle operates between 5 and 40 °C. The system performance is characterized by the overall system coefficient of performance (COPS) and the total mass flow rate of the working fluid for each kW cooling capacity ([Formula: see text]). The effects of different working parameters such as the evaporator, condenser, and boiler temperatures on the system performance are examined. The results illustrate that the maximum COPS values are attained using the highest boiling candidates with overhanging T-s diagram, i.e. R245fa and R600, while R600 has the lowest [Formula: see text] under the considered operating conditions. Among the proposed candidates, R600 is the best candidate for the ORC-VCR system from the perspectives of environmental issues and system performance. Nevertheless, its flammability should attract enough attention. The maximum COPS using R600 is found to reach up to 0.718 at a condenser temperature of 30 °C and the basic values for the remaining parameters. PMID:27489732

  17. Relief of Night-time Symptoms Associated With Gastroesophageal Reflux Disease Following 4 Weeks of Treatment With Pantoprazole Magnesium: The Mexican Gastroesophageal Reflux Disease Working Group

    PubMed Central

    Orr, William; Vargas-Romero, José Antonio; Remes-Troche, José María; Morales-Arámbula, Miguel; Soto-Pérez, Julio César; Mateos-Pérez, Gualberto; Sobrino-Cossío, Sergio; Teramoto-Matsubara, Oscar; López-Colombo, Aurelio; Orozco-Gamiz, Antonio; Saez-Ríos, Adolfo; Arellano-Plancarte, Araceli; Chiu-Ugalde, Jazmin; Tholen, Anne; Horbach, Silke; Lundberg, Lars; Fass, Ronnie

    2014-01-01

    Background/Aims To evaluate the effectiveness of pantoprazole magnesium (pantoprazole-Mg) 40 mg in the relief of esophageal and extra-esophageal symptoms of gastroesophageal reflux disease (GERD), particularly night-time symptoms. Methods Patients (aged 18-50 years) with 3-month history of heartburn and/or acid regurgitation plus at least one other symptom in the last week were enrolled in a nationwide, prospective and observational study in Mexico. Patients received pantoprazole-Mg 40 mg once daily during 4 weeks. Symptoms were assessed through a physician-administered structured interview and the patient-completed ReQuest in Practice™ questionnaire. Night-time GERD was defined as arousal from sleep during the night due to GERD-associated symptoms. Results Out of 4,343 patients included at basal visit, 3,665 were considered for the effectiveness per protocol analysis. At baseline, patients had a median of 8 GERD related symptoms. Patients with night-time GERD symptoms (42.7%) were more likely to have extra-esophageal symptoms (P < 0.001) than other GERD patients. Pantoprazole-Mg 40 mg once daily for 4 weeks improved a broad range of GERD-associated symptoms from baseline (80% reduction on physicians assessments; 68-77% reduction on ReQuest in Practice™ dimensions), including both day- and night-time GERD symptoms; improvements were the greatest for extra-esophageal symptoms in patients with night-time symptoms. Pantoprazole-Mg was well tolerated. Conclusions Pantoprazole-Mg 40 mg significantly improved a broad range of esophageal and extra-esophageal GERD related symptoms including sleep disturbances, as well as well-being, in patients with daytime or night-time GERD, making it a good option for patients with GERD, especially when extra-esophageal and night-time symptoms are present. PMID:24466446

  18. Compressing Aviation Data in XML Format

    NASA Technical Reports Server (NTRS)

    Patel, Hemil; Lau, Derek; Kulkarni, Deepak

    2003-01-01

    Design, operations and maintenance activities in aviation involve analysis of variety of aviation data. This data is typically in disparate formats making it difficult to use with different software packages. Use of a self-describing and extensible standard called XML provides a solution to this interoperability problem. XML provides a standardized language for describing the contents of an information stream, performing the same kind of definitional role for Web content as a database schema performs for relational databases. XML data can be easily customized for display using Extensible Style Sheets (XSL). While self-describing nature of XML makes it easy to reuse, it also increases the size of data significantly. Therefore, transfemng a dataset in XML form can decrease throughput and increase data transfer time significantly. It also increases storage requirements significantly. A natural solution to the problem is to compress the data using suitable algorithm and transfer it in the compressed form. We found that XML-specific compressors such as Xmill and XMLPPM generally outperform traditional compressors. However, optimal use of Xmill requires of discovery of optimal options to use while running Xmill. This, in turn, depends on the nature of data used. Manual disc0ver.y of optimal setting can require an engineer to experiment for weeks. We have devised an XML compression advisory tool that can analyze sample data files and recommend what compression tool would work the best for this data and what are the optimal settings to be used with a XML compression tool.

  19. Compression embedding

    DOEpatents

    Sandford, II, Maxwell T.; Handel, Theodore G.; Bradley, Jonathan N.

    1998-01-01

    A method and apparatus for embedding auxiliary information into the digital representation of host data created by a lossy compression technique and a method and apparatus for constructing auxiliary data from the correspondence between values in a digital key-pair table with integer index values existing in a representation of host data created by a lossy compression technique. The methods apply to data compressed with algorithms based on series expansion, quantization to a finite number of symbols, and entropy coding. Lossy compression methods represent the original data as ordered sequences of blocks containing integer indices having redundancy and uncertainty of value by one unit, allowing indices which are adjacent in value to be manipulated to encode auxiliary data. Also included is a method to improve the efficiency of lossy compression algorithms by embedding white noise into the integer indices. Lossy compression methods use loss-less compression to reduce to the final size the intermediate representation as indices. The efficiency of the loss-less compression, known also as entropy coding compression, is increased by manipulating the indices at the intermediate stage. Manipulation of the intermediate representation improves lossy compression performance by 1 to 10%.

  20. Compression embedding

    DOEpatents

    Sandford, M.T. II; Handel, T.G.; Bradley, J.N.

    1998-07-07

    A method and apparatus for embedding auxiliary information into the digital representation of host data created by a lossy compression technique and a method and apparatus for constructing auxiliary data from the correspondence between values in a digital key-pair table with integer index values existing in a representation of host data created by a lossy compression technique are disclosed. The methods apply to data compressed with algorithms based on series expansion, quantization to a finite number of symbols, and entropy coding. Lossy compression methods represent the original data as ordered sequences of blocks containing integer indices having redundancy and uncertainty of value by one unit, allowing indices which are adjacent in value to be manipulated to encode auxiliary data. Also included is a method to improve the efficiency of lossy compression algorithms by embedding white noise into the integer indices. Lossy compression methods use loss-less compression to reduce to the final size the intermediate representation as indices. The efficiency of the loss-less compression, known also as entropy coding compression, is increased by manipulating the indices at the intermediate stage. Manipulation of the intermediate representation improves lossy compression performance by 1 to 10%. 21 figs.

  1. Compression embedding

    DOEpatents

    Sandford, II, Maxwell T.; Handel, Theodore G.; Bradley, Jonathan N.

    1998-01-01

    A method of embedding auxiliary information into the digital representation of host data created by a lossy compression technique. The method applies to data compressed with lossy algorithms based on series expansion, quantization to a finite number of symbols, and entropy coding. Lossy compression methods represent the original data as integer indices having redundancy and uncertainty in value by one unit. Indices which are adjacent in value are manipulated to encode auxiliary data. By a substantially reverse process, the embedded auxiliary data can be retrieved easily by an authorized user. Lossy compression methods use loss-less compressions known also as entropy coding, to reduce to the final size the intermediate representation as indices. The efficiency of the compression entropy coding, known also as entropy coding is increased by manipulating the indices at the intermediate stage in the manner taught by the method.

  2. Compression embedding

    DOEpatents

    Sandford, M.T. II; Handel, T.G.; Bradley, J.N.

    1998-03-10

    A method of embedding auxiliary information into the digital representation of host data created by a lossy compression technique is disclosed. The method applies to data compressed with lossy algorithms based on series expansion, quantization to a finite number of symbols, and entropy coding. Lossy compression methods represent the original data as integer indices having redundancy and uncertainty in value by one unit. Indices which are adjacent in value are manipulated to encode auxiliary data. By a substantially reverse process, the embedded auxiliary data can be retrieved easily by an authorized user. Lossy compression methods use loss-less compressions known also as entropy coding, to reduce to the final size the intermediate representation as indices. The efficiency of the compression entropy coding, known also as entropy coding is increased by manipulating the indices at the intermediate stage in the manner taught by the method. 11 figs.

  3. Modeling Compressed Turbulence

    SciTech Connect

    Israel, Daniel M.

    2012-07-13

    From ICE to ICF, the effect of mean compression or expansion is important for predicting the state of the turbulence. When developing combustion models, we would like to know the mix state of the reacting species. This involves density and concentration fluctuations. To date, research has focused on the effect of compression on the turbulent kinetic energy. The current work provides constraints to help development and calibration for models of species mixing effects in compressed turbulence. The Cambon, et al., re-scaling has been extended to buoyancy driven turbulence, including the fluctuating density, concentration, and temperature equations. The new scalings give us helpful constraints for developing and validating RANS turbulence models.

  4. Compressive Holography

    NASA Astrophysics Data System (ADS)

    Lim, Se Hoon

    Compressive holography estimates images from incomplete data by using sparsity priors. Compressive holography combines digital holography and compressive sensing. Digital holography consists of computational image estimation from data captured by an electronic focal plane array. Compressive sensing enables accurate data reconstruction by prior knowledge on desired signal. Computational and optical co-design optimally supports compressive holography in the joint computational and optical domain. This dissertation explores two examples of compressive holography: estimation of 3D tomographic images from 2D data and estimation of images from under sampled apertures. Compressive holography achieves single shot holographic tomography using decompressive inference. In general, 3D image reconstruction suffers from underdetermined measurements with a 2D detector. Specifically, single shot holographic tomography shows the uniqueness problem in the axial direction because the inversion is ill-posed. Compressive sensing alleviates the ill-posed problem by enforcing some sparsity constraints. Holographic tomography is applied for video-rate microscopic imaging and diffuse object imaging. In diffuse object imaging, sparsity priors are not valid in coherent image basis due to speckle. So incoherent image estimation is designed to hold the sparsity in incoherent image basis by support of multiple speckle realizations. High pixel count holography achieves high resolution and wide field-of-view imaging. Coherent aperture synthesis can be one method to increase the aperture size of a detector. Scanning-based synthetic aperture confronts a multivariable global optimization problem due to time-space measurement errors. A hierarchical estimation strategy divides the global problem into multiple local problems with support of computational and optical co-design. Compressive sparse aperture holography can be another method. Compressive sparse sampling collects most of significant field

  5. The Growing Diversity of Work Schedules.

    ERIC Educational Resources Information Center

    Smith, Shirley J.

    1986-01-01

    The author highlights the predominance of the five-day, 40-hour workweek. Although finding little change in recent years in the proportion of workers on 40-hour schedules, Smith notes that there have been some changes in work patterns, with a still small but growing group of workers on "compressed" full-time weeks of less than five days. (CT)

  6. Care of critically ill surgical patients using the 80-hour Accreditation Council of Graduate Medical Education work-week guidelines: a survey of current strategies.

    PubMed

    Gordon, Chad R; Axelrad, Alex; Alexander, James B; Dellinger, R Phillip; Ross, Steven E

    2006-06-01

    As a result of the recently mandated work-hour restrictions, it has become more difficult to provide 24-hour intensive care unit (ICU) in-house coverage by the general surgical residents. To assess the current state of providing appropriate continuous care to surgical critical care patients during the era of resident work-hour constraints, a national survey was conducted by the Association of Program Directors of Surgery. The results revealed that 37 per cent of programs surveyed have residents other than general surgery housestaff providing cross-coverage and writing orders for surgical ICU patients. Residents in emergency medicine, anesthesia, family medicine, otorhinolaryngology, obstetrics/gynecology, internal medicine, urology, and orthopedic surgery have provided this cross-coverage. Some found it necessary to use physician extenders (i.e., nurse practitioners or physician assistants), thereby decreasing the burden of surgical housestaff coverage. The results indicated that 30 per cent use physician extenders to help cover the ICU during daytime hours and 11 per cent used them during nighttime hours. In addition, 24 per cent used a "night-float" system in an attempt to maintain continuous care, yet still adhere to the mandated guidelines. In conclusion, our survey found multiple strategies, including the use of physician extenders, a "night-float" system, and the use of nongeneral surgical residents in an attempt to provide continuous coverage for surgical ICU patients. The overall outcome of these new strategies still needs to be assessed before any beneficial results can be demonstrated. PMID:16808201

  7. Compressible halftoning

    NASA Astrophysics Data System (ADS)

    Anderson, Peter G.; Liu, Changmeng

    2003-01-01

    We present a technique for converting continuous gray-scale images to halftone (black and white) images that lend themselves to lossless data compression with compression factor of three or better. Our method involves using novel halftone mask structures which consist of non-repeated threshold values. We have versions of both dispersed-dot and clustered-dot masks, which produce acceptable images for a variety of printers. Using the masks as a sort key allows us to reversibly rearrange the image pixels and partition them into groups with a highly skewed distribution allowing Huffman compression coding techniques to be applied. This gives compression ratios in the range 3:1 to 10:1.

  8. That Wonderful 12-Hour Work Week.

    ERIC Educational Resources Information Center

    Shulman, Carol Herrnstadt

    1981-01-01

    Effective use of faculty is an important consideration in the need for accountability as institutions must maintain institutional quality while increasing operational efficiency. Collective bargaining and new federal reporting requirements for faculty necessitate a continuing focus on workload issues. (MLW)

  9. Video Compression

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Optivision developed two PC-compatible boards and associated software under a Goddard Space Flight Center Small Business Innovation Research grant for NASA applications in areas such as telerobotics, telesciences and spaceborne experimentation. From this technology, the company used its own funds to develop commercial products, the OPTIVideo MPEG Encoder and Decoder, which are used for realtime video compression and decompression. They are used in commercial applications including interactive video databases and video transmission. The encoder converts video source material to a compressed digital form that can be stored or transmitted, and the decoder decompresses bit streams to provide high quality playback.

  10. [Compression material].

    PubMed

    Perceau, Géraldine; Faure, Christine

    2012-01-01

    The compression of a venous ulcer is carried out with the use of bandages, and for less exudative ulcers, with socks, stockings or tights. The system of bandages is complex. Different forms of extension and therefore different types of models exist. PMID:22489428

  11. Compressed Genotyping

    PubMed Central

    Erlich, Yaniv; Gordon, Assaf; Brand, Michael; Hannon, Gregory J.; Mitra, Partha P.

    2011-01-01

    Over the past three decades we have steadily increased our knowledge on the genetic basis of many severe disorders. Nevertheless, there are still great challenges in applying this knowledge routinely in the clinic, mainly due to the relatively tedious and expensive process of genotyping. Since the genetic variations that underlie the disorders are relatively rare in the population, they can be thought of as a sparse signal. Using methods and ideas from compressed sensing and group testing, we have developed a cost-effective genotyping protocol to detect carriers for severe genetic disorders. In particular, we have adapted our scheme to a recently developed class of high throughput DNA sequencing technologies. The mathematical framework presented here has some important distinctions from the ’traditional’ compressed sensing and group testing frameworks in order to address biological and technical constraints of our setting. PMID:21451737

  12. Astronomical context coder for image compression

    NASA Astrophysics Data System (ADS)

    Pata, Petr; Schindler, Jaromir

    2015-10-01

    Recent lossless still image compression formats are powerful tools for compression of all kind of common images (pictures, text, schemes, etc.). Generally, the performance of a compression algorithm depends on its ability to anticipate the image function of the processed image. In other words, a compression algorithm to be successful, it has to take perfectly the advantage of coded image properties. Astronomical data form a special class of images and they have, among general image properties, also some specific characteristics which are unique. If a new coder is able to correctly use the knowledge of these special properties it should lead to its superior performance on this specific class of images at least in terms of the compression ratio. In this work, the novel lossless astronomical image data compression method will be presented. The achievable compression ratio of this new coder will be compared to theoretical lossless compression limit and also to the recent compression standards of the astronomy and general multimedia.

  13. Effect of internal heating during hot compression testing on the stress-strain behavior and hot working characteristics of Alloy 304L

    SciTech Connect

    Mataya, M.C.; Sackschewsky, V.E.

    1993-05-01

    Temperature change from conversion of deformation to internal heat, and its effect on stress-strain behavior of alloy 304L was investigated by initially isothermal (temperature of specimen, compression dies, environment equilibrated at initiation of test) uniaxial compression. Strain rate was varied 0.01 s{sup {minus}1} to 1 s{sup {minus}1} (thermal state of specimen varied from nearly isothermal to nearly adiabatic). Specimens were deformed at 750 to 1150 to a strain of 1. Change in temperature with strain was calculated via finite element analysis from measured stress-strain data and predictions were confirmed with thermocouples to verify the model. Temperature increased nearly linearly at the highest strain rate, consistent with temperature rise being a linear function of strain (adiabatic). As strain rate was lowered, heat transfer from superheated specimen to cooler dies caused sample temperature to increase and then decrease with strain as the sample thinned and specimen-die contact area increased. As-measured stress was corrected. Resulting isothermal flow curves were compared to predictions of a simplified method suggested by Thomas and Shrinivasan and differences are discussed. Strain rate sensitivity, activation energy for deformation, and flow curve peak associated with onset of dynamic recrystallization were determined from both as-measured and isothermal stress-strain data and found to vary widely. The impact of utilizing as-measured stress-strain data, not corrected for internal heating, on results of a number of published investigations is discussed.

  14. 100 Weekly Sky Maps

    NASA Technical Reports Server (NTRS)

    2002-01-01

    100 Aum Weekly Sky Maps for mission weeks 4 to 44, and the 100 Aum Annual Average Map. Shows sky coverage each week of the DIRBE mission over the period during which the COBE cryogen supply lasted. As the Earth, with COBE in orbit, revolved around the Sun, DIRBE viewed the sky from an ever-changing vantage point in the solar system, enabling light reflected and emitted by the interplanetary dust cloud to be modeled.

  15. Analytical model for ramp compression

    NASA Astrophysics Data System (ADS)

    Xue, Quanxi; Jiang, Shaoen; Wang, Zhebin; Wang, Feng; Hu, Yun; Ding, Yongkun

    2016-08-01

    An analytical ramp compression model for condensed matter, which can provide explicit solutions for isentropic compression flow fields, is reported. A ramp compression experiment can be easily designed according to the capability of the loading source using this model. Specifically, important parameters, such as the maximum isentropic region width, material properties, profile of the pressure pulse, and the pressure pulse duration can be reasonably allocated or chosen. To demonstrate and study this model, laser-direct-driven ramp compression experiments and code simulation are performed successively, and the factors influencing the accuracy of the model are studied. The application and simulation show that this model can be used as guidance in the design of a ramp compression experiment. However, it is verified that further optimization work is required for a precise experimental design.

  16. Compression and venous ulcers.

    PubMed

    Stücker, M; Link, K; Reich-Schupke, S; Altmeyer, P; Doerler, M

    2013-03-01

    Compression therapy is considered to be the most important conservative treatment of venous leg ulcers. Until a few years ago, compression bandages were regarded as first-line therapy of venous leg ulcers. However, to date medical compression stockings are the first choice of treatment. With respect to compression therapy of venous leg ulcers the following statements are widely accepted: 1. Compression improves the healing of ulcers when compared with no compression; 2. Multicomponent compression systems are more effective than single-component compression systems; 3. High compression is more effective than lower compression; 4. Medical compression stockings are more effective than compression with short stretch bandages. Healed venous leg ulcers show a high relapse rate without ongoing treatment. The use of medical stockings significantly reduces the amount of recurrent ulcers. Furthermore, the relapse rate of venous leg ulcers can be significantly reduced by a combination of compression therapy and surgery of varicose veins compared with compression therapy alone. PMID:23482538

  17. Measurement and control for mechanical compressive stress

    NASA Astrophysics Data System (ADS)

    Li, Qing; Ye, Guang; Pan, Lan; Wu, Xiushan

    2001-12-01

    At present, the indirect method is applied to measuring and controlling mechanical compressive stress, which is the measurement and control of rotating torque of screw with torque transducer during screw revolving. Because the friction coefficient between every screw-cap and washer, of screw-thread is different, the compressive stress of every screw may is different when the machinery is equipped. Therefore, the accurate measurement and control of mechanical compressive stress is realized by the direct measurement of mechanical compressive stress. The author introduces the research of contrast between compressive stress and rotating torque in the paper. The structure and work principle of a special washer type transducer is discussed emphatically. The special instrument cooperates with the washer type transducer for measuring and controlling mechanical compressive stress. The control tactics based on the rate of compressive stress is put to realize accurate control of mechanical compressive stress.

  18. Image compression using constrained relaxation

    NASA Astrophysics Data System (ADS)

    He, Zhihai

    2007-01-01

    In this work, we develop a new data representation framework, called constrained relaxation for image compression. Our basic observation is that an image is not a random 2-D array of pixels. They have to satisfy a set of imaging constraints so as to form a natural image. Therefore, one of the major tasks in image representation and coding is to efficiently encode these imaging constraints. The proposed data representation and image compression method not only achieves more efficient data compression than the state-of-the-art H.264 Intra frame coding, but also provides much more resilience to wireless transmission errors with an internal error-correction capability.

  19. Compressive beamforming.

    PubMed

    Xenaki, Angeliki; Gerstoft, Peter; Mosegaard, Klaus

    2014-07-01

    Sound source localization with sensor arrays involves the estimation of the direction-of-arrival (DOA) from a limited number of observations. Compressive sensing (CS) solves such underdetermined problems achieving sparsity, thus improved resolution, and can be solved efficiently with convex optimization. The DOA estimation problem is formulated in the CS framework and it is shown that CS has superior performance compared to traditional DOA estimation methods especially under challenging scenarios such as coherent arrivals and single-snapshot data. An offset and resolution analysis is performed to indicate the limitations of CS. It is shown that the limitations are related to the beampattern, thus can be predicted. The high-resolution capabilities and the robustness of CS are demonstrated on experimental array data from ocean acoustic measurements for source tracking with single-snapshot data. PMID:24993212

  20. MotorWeek

    SciTech Connect

    2009-01-01

    In 2008, PBS's MotorWeek, television's original automotive magazine, visited Argonne's Transportation Technology R&D Center "to learn what it really takes to make clean power sources a viable reality."

  1. MotorWeek

    ScienceCinema

    None

    2013-04-19

    In 2008, PBS's MotorWeek, television's original automotive magazine, visited Argonne's Transportation Technology R&D Center "to learn what it really takes to make clean power sources a viable reality."

  2. Compressive sensing exploiting wavelet-domain dependencies for ECG compression

    NASA Astrophysics Data System (ADS)

    Polania, Luisa F.; Carrillo, Rafael E.; Blanco-Velasco, Manuel; Barner, Kenneth E.

    2012-06-01

    Compressive sensing (CS) is an emerging signal processing paradigm that enables sub-Nyquist sampling of sparse signals. Extensive previous work has exploited the sparse representation of ECG signals in compression applications. In this paper, we propose the use of wavelet domain dependencies to further reduce the number of samples in compressive sensing-based ECG compression while decreasing the computational complexity. R wave events manifest themselves as chains of large coefficients propagating across scales to form a connected subtree of the wavelet coefficient tree. We show that the incorporation of this connectedness as additional prior information into a modified version of the CoSaMP algorithm can significantly reduce the required number of samples to achieve good quality in the reconstruction. This approach also allows more control over the ECG signal reconstruction, in particular, the QRS complex, which is typically distorted when prior information is not included in the recovery. The compression algorithm was tested upon records selected from the MIT-BIH arrhythmia database. Simulation results show that the proposed algorithm leads to high compression ratios associated with low distortion levels relative to state-of-the-art compression algorithms.

  3. COMPRESSION WAVES AND PHASE PLOTS: SIMULATIONS

    SciTech Connect

    Orlikowski, D; Minich, R

    2011-08-01

    Compression wave analysis started nearly 50 years ago with Fowles. Coperthwaite and Williams gave a method that helps identify simple and steady waves. We have been developing a method that gives describes the non-isentropic character of compression waves, in general. One result of that work is a simple analysis tool. Our method helps clearly identify when a compression wave is a simple wave, a steady wave (shock), and when the compression wave is in transition. This affects the analysis of compression wave experiments and the resulting extraction of the high-pressure equation of state.

  4. Progressive compressive imager

    NASA Astrophysics Data System (ADS)

    Evladov, Sergei; Levi, Ofer; Stern, Adrian

    2012-06-01

    We have designed and built a working automatic progressive sampling imaging system based on the vector sensor concept, which utilizes a unique sampling scheme of Radon projections. This sampling scheme makes it possible to progressively add information resulting in tradeoff between compression and the quality of reconstruction. The uniqueness of our sampling is that in any moment of the acquisition process the reconstruction can produce a reasonable version of the image. The advantage of the gradual addition of the samples is seen when the sparsity rate of the object is unknown, and thus the number of needed measurements. We have developed the iterative algorithm OSO (Ordered Sets Optimization) which employs our sampling scheme for creation of nearly uniform distributed sets of samples, which allows the reconstruction of Mega-Pixel images. We present the good quality reconstruction from compressed data ratios of 1:20.

  5. Compression of echocardiographic scan line data using wavelet packet transform

    NASA Technical Reports Server (NTRS)

    Hang, X.; Greenberg, N. L.; Qin, J.; Thomas, J. D.

    2001-01-01

    An efficient compression strategy is indispensable for digital echocardiography. Previous work has suggested improved results utilizing wavelet transforms in the compression of 2D echocardiographic images. Set partitioning in hierarchical trees (SPIHT) was modified to compress echocardiographic scanline data based on the wavelet packet transform. A compression ratio of at least 94:1 resulted in preserved image quality.

  6. 30 CFR 75.364 - Weekly examination.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Weekly examination. 75.364 Section 75.364... MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.364 Weekly examination. (a) Worked-out... bleeder system. (b) Hazardous conditions. At least every 7 days, an examination for hazardous...

  7. 76 FR 28623 - Small Business Week, 2011

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-18

    ... United States of America the two hundred and thirty-fifth. (Presidential Sig.) [FR Doc. 2011-12307 Filed... Documents#0;#0; #0; #0;Title 3-- #0;The President ] Proclamation 8673 of May 12, 2011 Small Business Week... to work hard enough, you can succeed in our country. This week, we honor and celebrate...

  8. FRESCO: Referential compression of highly similar sequences.

    PubMed

    Wandelt, Sebastian; Leser, Ulf

    2013-01-01

    In many applications, sets of similar texts or sequences are of high importance. Prominent examples are revision histories of documents or genomic sequences. Modern high-throughput sequencing technologies are able to generate DNA sequences at an ever-increasing rate. In parallel to the decreasing experimental time and cost necessary to produce DNA sequences, computational requirements for analysis and storage of the sequences are steeply increasing. Compression is a key technology to deal with this challenge. Recently, referential compression schemes, storing only the differences between a to-be-compressed input and a known reference sequence, gained a lot of interest in this field. In this paper, we propose a general open-source framework to compress large amounts of biological sequence data called Framework for REferential Sequence COmpression (FRESCO). Our basic compression algorithm is shown to be one to two orders of magnitudes faster than comparable related work, while achieving similar compression ratios. We also propose several techniques to further increase compression ratios, while still retaining the advantage in speed: 1) selecting a good reference sequence; and 2) rewriting a reference sequence to allow for better compression. In addition,we propose a new way of further boosting the compression ratios by applying referential compression to already referentially compressed files (second-order compression). This technique allows for compression ratios way beyond state of the art, for instance,4,000:1 and higher for human genomes. We evaluate our algorithms on a large data set from three different species (more than 1,000 genomes, more than 3 TB) and on a collection of versions of Wikipedia pages. Our results show that real-time compression of highly similar sequences at high compression ratios is possible on modern hardware. PMID:24524158

  9. Dad's Last Week.

    PubMed

    DeVoe, Jennifer E

    2016-05-01

    I had intended to spend our spring break week in Montana with my kids and my dad, going to parks and museums together. Instead, I spent the week in the hospital, helping my dad make end-of-life choices and learning more about the importance of communication in health care settings and the preciousness of close relationships in life. I am a better person and a better physician because my dad trusted me to be there while he was dying. During his last week, I was grateful to have spent years studying medicine and years getting to know my dad. This combination of professional and personal knowledge enabled me to help him choose his own end-of-life path. As someone who does not like hospitals, I have always wondered why I became a doctor; now I know. PMID:27185000

  10. Earth Science Week evolves

    NASA Astrophysics Data System (ADS)

    Earth Science Week, October 7-13, is an annual grassroots effort sponsored by the American Geological Institute (AGI) and its member societies, of which AGU is the largest. This year, for the first time, Earth Science Week has a general theme, evolution in Earth history. The Earth Science Week information kit for 2001, available from AGI, includes a variety of posters, bookmarks, and other materials that illustrate this concept. The kit contains a new 32-page “Ideas and Activities” booklet that emphasizes evolution in Earth history through an array of activities about rocks, fossils, and geologic time. It also has information on the upcoming Public Broadcasting Service series, “Evolution,” which is to be aired in late September.

  11. Effect of plate working length on plate stiffness and cyclic fatigue life in a cadaveric femoral fracture gap model stabilized with a 12-hole 2.4 mm locking compression plate

    PubMed Central

    2013-01-01

    Background There are several factors that can affect the fatigue life of a bone plate, including the mechanical properties of the plate and the complexity of the fracture. The position of the screws can influence construct stiffness, plate strain and cyclic fatigue of the implants. Studies have not investigated these variables in implants utilized for long bone fracture fixation in dogs and cats. The purpose of the present study was to evaluate the effect of plate working length on construct stiffness, gap motion and resistance to cyclic fatigue of dog femora with a simulated fracture gap stabilized using a 12-hole 2.4 mm locking compression plates (LCP). Femora were plated with 12-hole 2.4 mm LCP using 2 screws per fracture segment (long working length group) or with 12-hole 2.4 mm LCP using 5 screws per fracture segment (a short working length group). Results Construct stiffness did not differ significantly between stabilization techniques. Implant failure did not occur in any of the plated femora during cycling. Mean ± SD yield load at failure in the short plate working length group was significantly higher than in the long plate working length group. Conclusion In a femoral fracture gap model stabilized with a 2.4 mm LCP applied in contact with the bone, plate working length had no effect on stiffness, gap motion and resistance to fatigue. The short plate working length constructs failed at higher loads; however, yield loads for both the short and long plate working length constructs were within physiologic range. PMID:23800317

  12. Efficient Compression of High Resolution Climate Data

    NASA Astrophysics Data System (ADS)

    Yin, J.; Schuchardt, K. L.

    2011-12-01

    resolution climate data can be massive. Those data can consume a huge amount of disk space for storage, incur significant overhead for outputting data during simulation, introduce high latency for visualization and analysis, and may even make interactive visualization and analysis impossible given the limit of the data that a conventional cluster can handle. These problems can be alleviated by with effective and efficient data compression techniques. Even though HDF5 format supports compression, previous work has mainly focused on employ traditional general purpose compression schemes such as dictionary coder and block sorting based compression scheme. Those compression schemes mainly focus on encoding repeated byte sequences efficiently and are not well suitable for compressing climate data consist mainly of distinguished float point numbers. We plan to select and customize our compression schemes according to the characteristics of high-resolution climate data. One observation on high resolution climate data is that as the resolution become higher, values of various climate variables such as temperature and pressure, become closer in nearby cells. This provides excellent opportunities for predication-based compression schemes. We have performed a preliminary estimation of compression ratios of a very simple minded predication-based compression ratio in which we compute the difference between current float point number with previous float point number and then encoding the exponent and significance part of the float point number with entropy-based compression scheme. Our results show that we can achieve higher compression ratios between 2 and 3 in lossless compression, which is significantly higher than traditional compression algorithms. We have also developed lossy compression with our techniques. We can achive orders of magnitude data reduction while ensure error bounds. Moreover, our compression scheme is much more efficient and introduces much less overhead

  13. Efficient Lossy Compression for Compressive Sensing Acquisition of Images in Compressive Sensing Imaging Systems

    PubMed Central

    Li, Xiangwei; Lan, Xuguang; Yang, Meng; Xue, Jianru; Zheng, Nanning

    2014-01-01

    Compressive Sensing Imaging (CSI) is a new framework for image acquisition, which enables the simultaneous acquisition and compression of a scene. Since the characteristics of Compressive Sensing (CS) acquisition are very different from traditional image acquisition, the general image compression solution may not work well. In this paper, we propose an efficient lossy compression solution for CS acquisition of images by considering the distinctive features of the CSI. First, we design an adaptive compressive sensing acquisition method for images according to the sampling rate, which could achieve better CS reconstruction quality for the acquired image. Second, we develop a universal quantization for the obtained CS measurements from CS acquisition without knowing any a priori information about the captured image. Finally, we apply these two methods in the CSI system for efficient lossy compression of CS acquisition. Simulation results demonstrate that the proposed solution improves the rate-distortion performance by 0.4∼2 dB comparing with current state-of-the-art, while maintaining a low computational complexity. PMID:25490597

  14. TEM Video Compressive Sensing

    SciTech Connect

    Stevens, Andrew J.; Kovarik, Libor; Abellan, Patricia; Yuan, Xin; Carin, Lawrence; Browning, Nigel D.

    2015-08-02

    One of the main limitations of imaging at high spatial and temporal resolution during in-situ TEM experiments is the frame rate of the camera being used to image the dynamic process. While the recent development of direct detectors has provided the hardware to achieve frame rates approaching 0.1ms, the cameras are expensive and must replace existing detectors. In this paper, we examine the use of coded aperture compressive sensing methods [1, 2, 3, 4] to increase the framerate of any camera with simple, low-cost hardware modifications. The coded aperture approach allows multiple sub-frames to be coded and integrated into a single camera frame during the acquisition process, and then extracted upon readout using statistical compressive sensing inversion. Our simulations show that it should be possible to increase the speed of any camera by at least an order of magnitude. Compressive Sensing (CS) combines sensing and compression in one operation, and thus provides an approach that could further improve the temporal resolution while correspondingly reducing the electron dose rate. Because the signal is measured in a compressive manner, fewer total measurements are required. When applied to TEM video capture, compressive imaging couled improve acquisition speed and reduce the electron dose rate. CS is a recent concept, and has come to the forefront due the seminal work of Candès [5]. Since the publication of Candès, there has been enormous growth in the application of CS and development of CS variants. For electron microscopy applications, the concept of CS has also been recently applied to electron tomography [6], and reduction of electron dose in scanning transmission electron microscopy (STEM) imaging [7]. To demonstrate the applicability of coded aperture CS video reconstruction for atomic level imaging, we simulate compressive sensing on observations of Pd nanoparticles and Ag nanoparticles during exposure to high temperatures and other environmental

  15. Compression of Cake

    NASA Astrophysics Data System (ADS)

    Nason, Sarah; Houghton, Brittany; Renfro, Timothy

    2012-03-01

    The fall university physics class, at McMurry University, created a compression modulus experiment that even high school students could do. The class came up with this idea after a Young's modulus experiment which involved stretching wire. A question was raised of what would happen if we compressed something else? We created our own Young's modulus experiment, but in a more entertaining way. The experiment involves measuring the height of a cake both before and after a weight has been applied to the cake. We worked to derive the compression modulus by applying weight to a cake. In the end, we had our experimental cake and, ate it too! To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2012.TSS.B1.1

  16. A Week for Space

    ERIC Educational Resources Information Center

    Comstock, Diane

    2008-01-01

    Space Week focuses on concepts that enable students to make concrete observations in the early grades (K-2) and move to concepts that help students develop their internet research and writing skills in middle and upper grades (Grades 3-5), and culminates with the development of science investigation design skills (Grade 6). To help launch your…

  17. Swahili 12 Weeks Course.

    ERIC Educational Resources Information Center

    Defense Language Inst., Washington, DC.

    This 12-weeks course in basic Swahili comprises 55 lesson units in five volumes. The general course format consists of (1) perception drills for comprehension, oral production, and association using "situational picture" illustrations; (2) dialogs in English and Swahili, with cartoon guides; (3) sequenced pattern and recombination drills, and (4)…

  18. Phun Week: Understanding Physiology

    ERIC Educational Resources Information Center

    Limson, Mel; Matyas, Marsha Lakes

    2009-01-01

    Topics such as sports, exercise, health, and nutrition can make the science of physiology relevant and engaging for students. In addition, many lessons on these topics, such as those on the cardiovascular, respiratory, and digestive systems, align with national and state life science education standards. Physiology Understanding Week (PhUn…

  19. A Week of Observations

    ERIC Educational Resources Information Center

    Colasacco, Jenne

    2011-01-01

    Even the most effective teachers have room to grow, but it's not always easy for principals to give adequate guidance through short observations. High school principal Jenne Colasacco decided to bring more depth to her observations by observing each of her teachers during one class for an entire week. The new observation structure, which included…

  20. Turbulence in Compressible Flows

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Lecture notes for the AGARD Fluid Dynamics Panel (FDP) Special Course on 'Turbulence in Compressible Flows' have been assembled in this report. The following topics were covered: Compressible Turbulent Boundary Layers, Compressible Turbulent Free Shear Layers, Turbulent Combustion, DNS/LES and RANS Simulations of Compressible Turbulent Flows, and Case Studies of Applications of Turbulence Models in Aerospace.

  1. Family planning week in Ukraine.

    PubMed

    Antarsh, L

    1997-01-01

    More than 600 events, including disco dances, seminars, and training courses for health professionals, took place during National Family Planning Week, held throughout Ukraine this year from May 26 to June 1. The events were announced on the radio, television, and in newspapers in every region of the country. The following are among the events which took place during the week: physicians gave presents and contraceptives to mothers of newborn infants in maternity hospitals in Dnipropetrovsk; loudspeakers blared messages about family planning in the most crowded streets of Sevastopol, Crimea; family planning rooms and centers opened in 8 districts of Rivninska; and every region of the country held an official opening ceremony. Many of the events had a special focus upon youth, with more than 200 events for adolescents. For more than 6 months, a special multi-ministry coordinating committee worked closely with AVSC to make this first-time event a reality. Public awareness of family planning increased as a result of the Week. Ukraine's Ministry of Health is looking forward to holding the event again next year with or without the support of outside agencies. PMID:12349011

  2. a week in space

    NASA Astrophysics Data System (ADS)

    collette, christian

    2016-04-01

    COLLETTE Christian Institut Saint Laurent Liège Belgium. I am a science teacher at a technical high school. Generally, my students don't come from a privileged social background and are not particularly motivated for studies. For 10 years, I organize, for one of my sections, a spatial (and special) school year that ends in a spatial week. Throughout this year, with the help of my colleagues, I will introduce into all themes a lot of concepts relating to space. French, history, geography, English, mathematics, technical courses, sciences, and even gymnastics will be training actors in space culture. In spring, I will accompany my class in the Euro Space Center (Redu- Belgium) where we will live one week 24 hours on "like astronauts" One third of the time is dedicated to astronaut training (moonwalk, remote manipulator system, mission simulation, weightless wall, building rockets, satellites, etc.), One third to more intellectual activities on space (lectures, research, discovery of the outside run) the last one third of time in outside visits (museums, site of ESA-Redu) or in movies about space (October sky, Apollo 13, etc.) During this year, the profits, so educational as human, are considerable!

  3. Atomic effect algebras with compression bases

    SciTech Connect

    Caragheorgheopol, Dan; Tkadlec, Josef

    2011-01-15

    Compression base effect algebras were recently introduced by Gudder [Demonstr. Math. 39, 43 (2006)]. They generalize sequential effect algebras [Rep. Math. Phys. 49, 87 (2002)] and compressible effect algebras [Rep. Math. Phys. 54, 93 (2004)]. The present paper focuses on atomic compression base effect algebras and the consequences of atoms being foci (so-called projections) of the compressions in the compression base. Part of our work generalizes results obtained in atomic sequential effect algebras by Tkadlec [Int. J. Theor. Phys. 47, 185 (2008)]. The notion of projection-atomicity is introduced and studied, and several conditions that force a compression base effect algebra or the set of its projections to be Boolean are found. Finally, we apply some of these results to sequential effect algebras and strengthen a previously established result concerning a sufficient condition for them to be Boolean.

  4. Atomic effect algebras with compression bases

    NASA Astrophysics Data System (ADS)

    Caragheorgheopol, Dan; Tkadlec, Josef

    2011-01-01

    Compression base effect algebras were recently introduced by Gudder [Demonstr. Math. 39, 43 (2006)]. They generalize sequential effect algebras [Rep. Math. Phys. 49, 87 (2002)] and compressible effect algebras [Rep. Math. Phys. 54, 93 (2004)]. The present paper focuses on atomic compression base effect algebras and the consequences of atoms being foci (so-called projections) of the compressions in the compression base. Part of our work generalizes results obtained in atomic sequential effect algebras by Tkadlec [Int. J. Theor. Phys. 47, 185 (2008)]. The notion of projection-atomicity is introduced and studied, and several conditions that force a compression base effect algebra or the set of its projections to be Boolean are found. Finally, we apply some of these results to sequential effect algebras and strengthen a previously established result concerning a sufficient condition for them to be Boolean.

  5. Learning in compressed space.

    PubMed

    Fabisch, Alexander; Kassahun, Yohannes; Wöhrle, Hendrik; Kirchner, Frank

    2013-06-01

    We examine two methods which are used to deal with complex machine learning problems: compressed sensing and model compression. We discuss both methods in the context of feed-forward artificial neural networks and develop the backpropagation method in compressed parameter space. We further show that compressing the weights of a layer of a multilayer perceptron is equivalent to compressing the input of the layer. Based on this theoretical framework, we will use orthogonal functions and especially random projections for compression and perform experiments in supervised and reinforcement learning to demonstrate that the presented methods reduce training time significantly. PMID:23501172

  6. Futures Week. Middle School Program. Instructor's Guidebook.

    ERIC Educational Resources Information Center

    Smith, Armenia

    This instructor's guide outlines a model program designed to provide middle school students with an opportunity to participate in exploratory activities regarding the world of work and to understand the relationships between education and work. Described in the first part of the manual are the following futures week activities: a job interviewing…

  7. Extended testing of compression distillation.

    NASA Technical Reports Server (NTRS)

    Bambenek, R. A.; Nuccio, P. P.

    1972-01-01

    During the past eight years, the NASA Manned Spacecraft Center has supported the development of an integrated water and waste management system which includes the compression distillation process for recovering useable water from urine, urinal flush water, humidity condensate, commode flush water, and concentrated wash water. This paper describes the design of the compression distillation unit, developed for this system, and the testing performed to demonstrate its reliability and performance. In addition, this paper summarizes the work performed on pretreatment and post-treatment processes, to assure the recovery of sterile potable water from urine and treated urinal flush water.

  8. Data compression using Chebyshev transform

    NASA Technical Reports Server (NTRS)

    Cheng, Andrew F. (Inventor); Hawkins, III, S. Edward (Inventor); Nguyen, Lillian (Inventor); Monaco, Christopher A. (Inventor); Seagrave, Gordon G. (Inventor)

    2007-01-01

    The present invention is a method, system, and computer program product for implementation of a capable, general purpose compression algorithm that can be engaged on the fly. This invention has particular practical application with time-series data, and more particularly, time-series data obtained form a spacecraft, or similar situations where cost, size and/or power limitations are prevalent, although it is not limited to such applications. It is also particularly applicable to the compression of serial data streams and works in one, two, or three dimensions. The original input data is approximated by Chebyshev polynomials, achieving very high compression ratios on serial data streams with minimal loss of scientific information.

  9. Microbunching and RF Compression

    SciTech Connect

    Venturini, M.; Migliorati, M.; Ronsivalle, C.; Ferrario, M.; Vaccarezza, C.

    2010-05-23

    Velocity bunching (or RF compression) represents a promising technique complementary to magnetic compression to achieve the high peak current required in the linac drivers for FELs. Here we report on recent progress aimed at characterizing the RF compression from the point of view of the microbunching instability. We emphasize the development of a linear theory for the gain function of the instability and its validation against macroparticle simulations that represents a useful tool in the evaluation of the compression schemes for FEL sources.

  10. Compressed gas manifold

    DOEpatents

    Hildebrand, Richard J.; Wozniak, John J.

    2001-01-01

    A compressed gas storage cell interconnecting manifold including a thermally activated pressure relief device, a manual safety shut-off valve, and a port for connecting the compressed gas storage cells to a motor vehicle power source and to a refueling adapter. The manifold is mechanically and pneumatically connected to a compressed gas storage cell by a bolt including a gas passage therein.

  11. Compressible turbulent mixing: Effects of compressibility

    NASA Astrophysics Data System (ADS)

    Ni, Qionglin

    2016-04-01

    We studied by numerical simulations the effects of compressibility on passive scalar transport in stationary compressible turbulence. The turbulent Mach number varied from zero to unity. The difference in driven forcing was the magnitude ratio of compressive to solenoidal modes. In the inertial range, the scalar spectrum followed the k-5 /3 scaling and suffered negligible influence from the compressibility. The growth of the Mach number showed (1) a first reduction and second enhancement in the transfer of scalar flux; (2) an increase in the skewness and flatness of the scalar derivative and a decrease in the mixed skewness and flatness of the velocity-scalar derivatives; (3) a first stronger and second weaker intermittency of scalar relative to that of velocity; and (4) an increase in the intermittency parameter which measures the intermittency of scalar in the dissipative range. Furthermore, the growth of the compressive mode of forcing indicated (1) a decrease in the intermittency parameter and (2) less efficiency in enhancing scalar mixing. The visualization of scalar dissipation showed that, in the solenoidal-forced flow, the field was filled with the small-scale, highly convoluted structures, while in the compressive-forced flow, the field was exhibited as the regions dominated by the large-scale motions of rarefaction and compression.

  12. Compressed hyperspectral sensing

    NASA Astrophysics Data System (ADS)

    Tsagkatakis, Grigorios; Tsakalides, Panagiotis

    2015-03-01

    Acquisition of high dimensional Hyperspectral Imaging (HSI) data using limited dimensionality imaging sensors has led to restricted capabilities designs that hinder the proliferation of HSI. To overcome this limitation, novel HSI architectures strive to minimize the strict requirements of HSI by introducing computation into the acquisition process. A framework that allows the integration of acquisition with computation is the recently proposed framework of Compressed Sensing (CS). In this work, we propose a novel HSI architecture that exploits the sampling and recovery capabilities of CS to achieve a dramatic reduction in HSI acquisition requirements. In the proposed architecture, signals from multiple spectral bands are multiplexed before getting recorded by the imaging sensor. Reconstruction of the full hyperspectral cube is achieved by exploiting a dictionary of elementary spectral profiles in a unified minimization framework. Simulation results suggest that high quality recovery is possible from a single or a small number of multiplexed frames.

  13. Compressively sensed complex networks.

    SciTech Connect

    Dunlavy, Daniel M.; Ray, Jaideep; Pinar, Ali

    2010-07-01

    The aim of this project is to develop low dimension parametric (deterministic) models of complex networks, to use compressive sensing (CS) and multiscale analysis to do so and to exploit the structure of complex networks (some are self-similar under coarsening). CS provides a new way of sampling and reconstructing networks. The approach is based on multiresolution decomposition of the adjacency matrix and its efficient sampling. It requires preprocessing of the adjacency matrix to make it 'blocky' which is the biggest (combinatorial) algorithm challenge. Current CS reconstruction algorithm makes no use of the structure of a graph, its very general (and so not very efficient/customized). Other model-based CS techniques exist, but not yet adapted to networks. Obvious starting point for future work is to increase the efficiency of reconstruction.

  14. An overview of semantic compression

    NASA Astrophysics Data System (ADS)

    Schmalz, Mark S.

    2010-08-01

    approaches are considered, ranging from low-level semantic compression for text and database compaction, to high-level semantic analysis of images or video in which objects of interest have been detected, segmented, and represented compactly to facilitate indexing. In particular, we overview previous work in semantic pattern recognition, and how this has been applied to object-based compression. Discussion centers on lossless versus lossy transformations, quality of service in lossy compression, and computational efficiency.

  15. Prelude to compressed baryonic matter

    NASA Astrophysics Data System (ADS)

    Wilczek, Frank

    Why study compressed baryonic matter, or more generally strongly interacting matter at high densities and temperatures? Most obviously, because it's an important piece of Nature. The whole universe, in the early moments of the big bang, was filled with the stuff. Today, highly compressed baryonic matter occurs in neutron stars and during crucial moments in the development of supernovae. Also, working to understand compressed baryonic matter gives us new perspectives on ordinary baryonic matter, i.e. the matter in atomic nuclei. But perhaps the best answer is a variation on the one George Mallory gave, when asked why he sought to scale Mount Everest: Because, as a prominent feature in the landscape of physics, it's there. Compressed baryonic matter is a material we can produce in novel, challenging experiments that probe new extremes of temperature and density. On the theoretical side, it is a mathematically well-defined domain with a wealth of novel, challenging problems, as well as wide-ranging connections. Its challenges have already inspired a lot of very clever work, and revealed some wonderful surprises, as documented in this volume.

  16. The effects of compression garments on performance of prolonged manual-labour exercise and recovery.

    PubMed

    Chan, Val; Duffield, Rob; Watsford, Mark

    2016-02-01

    This study investigated the effects of wearing compression garments during and 24 h following a 4-h exercise protocol simulating manual-labour tasks. Ten physically trained male participants, familiar with labouring activities, undertook 4 h of work tasks characteristic of industrial workplaces. Participants completed 2 testing sessions, separated by at least 1 week. In the experimental condition, participants wore a full-length compression top and compression shorts during the exercise protocol and overnight recovery, with normal work clothes worn in the control condition. Testing for serum creatine kinase and C-reactive protein, handgrip strength, knee flexion and extension torque, muscle stiffness, perceived muscle soreness and fatigue as well as heart rate and rating of perceived exertion (RPE) responses to 4-min cycling were performed before, following, and 24 h after exercise. Creatine kinase, muscle soreness, and rating of perceived fatigue increased following the exercise protocol (p < 0.05) as did RPE to a standardised cycling warm-up bout. Conversely, no postexercise changes were observed in C-reactive protein, handgrip strength, peak knee flexion torque, or stiffness measures (p > 0.05). Knee extension torque was significantly higher in the control condition at 24 h postexercise (3.1% ± 5.4% change; compression: 2.2% ± 11.1% change), although no other variables were different between conditions at any time. However, compression demonstrated a moderate-large effect (d > 0.60) to reduce perceived muscle soreness, fatigue, and RPE from standardised warm-up at 24 h postexercise. The current findings suggest that compression may assist in perceptual recovery from manual-labour exercise with implications for the ability to perform subsequent work bouts. PMID:26778138

  17. Elective Delivery Before 39 Weeks

    MedlinePlus

    ... Delivery, and Postpartum Care Elective Delivery Before 39 Weeks • What is a “medically indicated” delivery? • What is ... the baby grow and develop during the last weeks of pregnancy? • What are the risks for babies ...

  18. Radiological Image Compression

    NASA Astrophysics Data System (ADS)

    Lo, Shih-Chung Benedict

    The movement toward digital images in radiology presents the problem of how to conveniently and economically store, retrieve, and transmit the volume of digital images. Basic research into image data compression is necessary in order to move from a film-based department to an efficient digital -based department. Digital data compression technology consists of two types of compression technique: error-free and irreversible. Error -free image compression is desired; however, present techniques can only achieve compression ratio of from 1.5:1 to 3:1, depending upon the image characteristics. Irreversible image compression can achieve a much higher compression ratio; however, the image reconstructed from the compressed data shows some difference from the original image. This dissertation studies both error-free and irreversible image compression techniques. In particular, some modified error-free techniques have been tested and the recommended strategies for various radiological images are discussed. A full-frame bit-allocation irreversible compression technique has been derived. A total of 76 images which include CT head and body, and radiographs digitized to 2048 x 2048, 1024 x 1024, and 512 x 512 have been used to test this algorithm. The normalized mean -square-error (NMSE) on the difference image, defined as the difference between the original and the reconstructed image from a given compression ratio, is used as a global measurement on the quality of the reconstructed image. The NMSE's of total of 380 reconstructed and 380 difference images are measured and the results tabulated. Three complex compression methods are also suggested to compress images with special characteristics. Finally, various parameters which would effect the quality of the reconstructed images are discussed. A proposed hardware compression module is given in the last chapter.

  19. Postprocessing of Compressed Images via Sequential Denoising

    NASA Astrophysics Data System (ADS)

    Dar, Yehuda; Bruckstein, Alfred M.; Elad, Michael; Giryes, Raja

    2016-07-01

    In this work we propose a novel postprocessing technique for compression-artifact reduction. Our approach is based on posing this task as an inverse problem, with a regularization that leverages on existing state-of-the-art image denoising algorithms. We rely on the recently proposed Plug-and-Play Prior framework, suggesting the solution of general inverse problems via Alternating Direction Method of Multipliers (ADMM), leading to a sequence of Gaussian denoising steps. A key feature in our scheme is a linearization of the compression-decompression process, so as to get a formulation that can be optimized. In addition, we supply a thorough analysis of this linear approximation for several basic compression procedures. The proposed method is suitable for diverse compression techniques that rely on transform coding. Specifically, we demonstrate impressive gains in image quality for several leading compression methods - JPEG, JPEG2000, and HEVC.

  20. The New CCSDS Image Compression Recommendation

    NASA Technical Reports Server (NTRS)

    Yeh, Pen-Shu; Armbruster, Philippe; Kiely, Aaron B.; Masschelein, Bart; Moury, Gilles; Schafer, Christoph

    2004-01-01

    The Consultative Committee for Space Data Systems (CCSDS) data compression working group has recently adopted a recommendation for image data compression, with a final release expected in 2005. The algorithm adopted in the recommendation consists a two dimensional discrete wavelet transform of the image, followed by progressive bit-plane coding of the transformed data. The algorithm can provide both lossless and lossy compression, and allows a user to directly control the compressed data volume or the fidelity with which the wavelet-transformed data can be reconstructed. The algorithm is suitable for both frame-based image data and scan-based sensor data, and has applications for near-earth and deep-space missions. The standard will be accompanied by free software sources on a future web site. An ASIC implementation of the compressor is currently under development. This paper describes the compression algorithm along with the requirements that drove the selection of the algorithm.

  1. Adaptive compressive sensing camera

    NASA Astrophysics Data System (ADS)

    Hsu, Charles; Hsu, Ming K.; Cha, Jae; Iwamura, Tomo; Landa, Joseph; Nguyen, Charles; Szu, Harold

    2013-05-01

    We have embedded Adaptive Compressive Sensing (ACS) algorithm on Charge-Coupled-Device (CCD) camera based on the simplest concept that each pixel is a charge bucket, and the charges comes from Einstein photoelectric conversion effect. Applying the manufactory design principle, we only allow altering each working component at a minimum one step. We then simulated what would be such a camera can do for real world persistent surveillance taking into account of diurnal, all weather, and seasonal variations. The data storage has saved immensely, and the order of magnitude of saving is inversely proportional to target angular speed. We did design two new components of CCD camera. Due to the matured CMOS (Complementary metal-oxide-semiconductor) technology, the on-chip Sample and Hold (SAH) circuitry can be designed for a dual Photon Detector (PD) analog circuitry for changedetection that predicts skipping or going forward at a sufficient sampling frame rate. For an admitted frame, there is a purely random sparse matrix [Φ] which is implemented at each bucket pixel level the charge transport bias voltage toward its neighborhood buckets or not, and if not, it goes to the ground drainage. Since the snapshot image is not a video, we could not apply the usual MPEG video compression and Hoffman entropy codec as well as powerful WaveNet Wrapper on sensor level. We shall compare (i) Pre-Processing FFT and a threshold of significant Fourier mode components and inverse FFT to check PSNR; (ii) Post-Processing image recovery will be selectively done by CDT&D adaptive version of linear programming at L1 minimization and L2 similarity. For (ii) we need to determine in new frames selection by SAH circuitry (i) the degree of information (d.o.i) K(t) dictates the purely random linear sparse combination of measurement data a la [Φ]M,N M(t) = K(t) Log N(t).

  2. Compressive optical imaging systems

    NASA Astrophysics Data System (ADS)

    Wu, Yuehao

    Compared to the classic Nyquist sampling theorem, Compressed Sensing or Compressive Sampling (CS) was proposed as a more efficient alternative for sampling sparse signals. In this dissertation, we discuss the implementation of the CS theory in building a variety of optical imaging systems. CS-based Imaging Systems (CSISs) exploit the sparsity of optical images in their transformed domains by imposing incoherent CS measurement patterns on them. The amplitudes and locations of sparse frequency components of optical images in their transformed domains can be reconstructed from the CS measurement results by solving an l1-regularized minimization problem. In this work, we review the theoretical background of the CS theory and present two hardware implementation schemes for CSISs, including a single pixel detector based scheme and an array detector based scheme. The first implementation scheme is suitable for acquiring Two-Dimensional (2D) spatial information of the imaging scene. We demonstrate the feasibility of this implementation scheme by developing a single pixel camera, a multispectral imaging system, and an optical sectioning microscope for fluorescence microscopy. The array detector based scheme is suitable for hyperspectral imaging applications, wherein both the spatial and spectral information of the imaging scene are of interest. We demonstrate the feasibility of this scheme by developing a Digital Micromirror Device-based Snapshot Spectral Imaging (DMD-SSI) system, which implements CS measurement processes on the Three-Dimensional (3D) spatial/spectral information of the imaging scene. Tens of spectral images can be reconstructed from the DMD-SSI system simultaneously without any mechanical or temporal scanning processes.

  3. Comparison of Artificial Compressibility Methods

    NASA Technical Reports Server (NTRS)

    Kiris, Cetin; Housman, Jeffrey; Kwak, Dochan

    2003-01-01

    Various artificial compressibility methods for calculating three-dimensional, steady and unsteady, laminar and turbulent, incompressible Navier-Stokes equations are compared in this work. Each method is described in detail along with appropriate physical and numerical boundary conditions. Analysis of well-posedness and numerical solutions to test problems for each method are provided. A comparison based on convergence behavior, accuracy, stability and robustness is used to establish the relative positive and negative characteristics of each method.

  4. Hyperspectral imaging using compressed sensing

    NASA Astrophysics Data System (ADS)

    Ramirez I., Gabriel Eduardo; Manian, Vidya B.

    2012-06-01

    Compressed sensing (CS) has attracted a lot of attention in recent years as a promising signal processing technique that exploits a signal's sparsity to reduce its size. It allows for simple compression that does not require a lot of additional computational power, and would allow physical implementation at the sensor using spatial light multiplexers using Texas Instruments (TI) digital micro-mirror device (DMD). The DMD can be used as a random measurement matrix, reflecting the image off the DMD is the equivalent of an inner product between the images individual pixels and the measurement matrix. CS however is asymmetrical, meaning that the signals recovery or reconstruction from the measurements does require a higher level of computation. This makes the prospect of working with the compressed version of the signal in implementations such as detection or classification much more efficient. If an initial analysis shows nothing of interest, the signal need not be reconstructed. Many hyper-spectral image applications are precisely focused on these areas, and would greatly benefit from a compression technique like CS that could help minimize the light sensor down to a single pixel, lowering costs associated with the cameras while reducing the large amounts of data generated by all the bands. The present paper will show an implementation of CS using a single pixel hyper-spectral sensor, and compare the reconstructed images to those obtained through the use of a regular sensor.

  5. Does Work Experience Actually Work?

    ERIC Educational Resources Information Center

    Field, John

    2012-01-01

    As unemployment levels rise, so education and training move into the policy spotlight. For the government, this is a very uncomfortable place to be right now. A number of large companies have withdrawn from the flagship Work Programme--under which jobseekers are invited to take up unpaid work placements of between two and eight weeks--amid…

  6. Parallel image compression

    NASA Technical Reports Server (NTRS)

    Reif, John H.

    1987-01-01

    A parallel compression algorithm for the 16,384 processor MPP machine was developed. The serial version of the algorithm can be viewed as a combination of on-line dynamic lossless test compression techniques (which employ simple learning strategies) and vector quantization. These concepts are described. How these concepts are combined to form a new strategy for performing dynamic on-line lossy compression is discussed. Finally, the implementation of this algorithm in a massively parallel fashion on the MPP is discussed.

  7. The Gurnham equation in characterizing the compressibility of pharmaceutical materials.

    PubMed

    Zhao, J; Burt, H M; Miller, R A

    2006-07-24

    Limitations of the Heckel equation in characterizing material compression behavior have been well reported. In this work, the Gurnham equation, which was first introduced in chemical engineering, is proposed as an alternate method of evaluating the compressibility of pharmaceutical powders. The Gurnham equation was adapted for tablet compression and the estimated slope parameter c was proposed to represent material compressibility. Data from the compression of four commonly used excipients (microcrystalline cellulose, corn starch, lactose monohydrate, and dibasic calcium phosphate dihydrate) and one drug (acetaminophen) were evaluated using the Gurnham equation. Using compression data at different peak pressures, linear relationships between porosity and lnPressure of the five materials were obtained. The determined parameter c expresses the compressibility of materials. The analysis of previous experimental data, including granulations, mixtures and co-processed materials also indicates that c might be a representative parameter for material compressibility. PMID:16678985

  8. Solar Week: Learning from Experience

    NASA Astrophysics Data System (ADS)

    Alexander, D.; Hauck, K.

    2003-12-01

    Solar Week is a week-long set of games and activities allowing students to interact directly with solar science and solar scientists. Solar Week was developed as a spin-off of the highly successful Yohkoh Public Outreach Project (YPOP). While YPOP provided access to solar images, movies and activities, the main goal of Solar Week was to enhance the participation of women, who are under-represented in the physical sciences. Solar Week achieves this by providing young women, primarily in grades 6-8, with access to role models in the sciences. The scientists participating in Solar Week are women from a variety of backgrounds and with a variety of scientific expertise. In this paper, our aim is to provide some insight into developing activity-based space science for the web and to discuss the lessons-learned from tailoring to a specific group of participants.

  9. Compressed Gas Safety for Experimental Fusion Facilities

    SciTech Connect

    Lee C. Cadwallader

    2004-09-01

    Experimental fusion facilities present a variety of hazards to the operators and staff. There are unique or specialized hazards, including magnetic fields, cryogens, radio frequency emissions, and vacuum reservoirs. There are also more general industrial hazards, such as a wide variety of electrical power, pressurized air, and cooling water systems in use, there are crane and hoist loads, working at height, and handling compressed gas cylinders. This paper outlines the projectile hazard assoicated with compressed gas cylinders and mthods of treatment to provide for compressed gas safety. This information should be of interest to personnel at both magnetic and inertial fusion experiments.

  10. Compressed Gas Safety for Experimental Fusion Facilities

    SciTech Connect

    Cadwallader, L.C.

    2005-05-15

    Experimental fusion facilities present a variety of hazards to the operators and staff. There are unique or specialized hazards, including magnetic fields, cryogens, radio frequency emissions, and vacuum reservoirs. There are also more general industrial hazards, such as a wide variety of electrical power, pressurized air and cooling water systems in use, there are crane and hoist loads, working at height, and handling compressed gas cylinders. This paper outlines the projectile hazard associated with compressed gas cylinders and methods of treatment to provide for compressed gas safety. This information should be of interest to personnel at both magnetic and inertial fusion experiments.

  11. 3D MHD Simulations of Spheromak Compression

    NASA Astrophysics Data System (ADS)

    Stuber, James E.; Woodruff, Simon; O'Bryan, John; Romero-Talamas, Carlos A.; Darpa Spheromak Team

    2015-11-01

    The adiabatic compression of compact tori could lead to a compact and hence low cost fusion energy system. The critical scientific issues in spheromak compression relate both to confinement properties and to the stability of the configuration undergoing compression. We present results from the NIMROD code modified with the addition of magnetic field coils that allow us to examine the role of rotation on the stability and confinement of the spheromak (extending prior work for the FRC). We present results from a scan in initial rotation, from 0 to 100km/s. We show that strong rotational shear (10km/s over 1cm) occurs. We compare the simulation results with analytic scaling relations for adiabatic compression. Work performed under DARPA grant N66001-14-1-4044.

  12. Compression of digital holographic data: an overview

    NASA Astrophysics Data System (ADS)

    Dufaux, Frederic; Xing, Yafei; Pesquet-Popescu, Beatrice; Schelkens, Peter

    2015-09-01

    Holography has the potential to become the ultimate 3D experience. Nevertheless, in order to achieve practical working systems, major scientific and technological challenges have to be tackled. In particular, as digital holographic data represents a huge amount of information, the development of efficient compression techniques is a key component. This problem has gained significant attention by the research community during the last 10 years. Given that holograms have very different signal properties when compared to natural images and video sequences, existing compression techniques (e.g. JPEG or MPEG) remain suboptimal, calling for innovative compression solutions. In this paper, we will review and analyze past and on-going work for the compression of digital holographic data.

  13. Selfsimilar Spherical Compression Waves in Gas Dynamics

    NASA Astrophysics Data System (ADS)

    Meyer-ter-Vehn, J.; Schalk, C.

    1982-08-01

    A synopsis of different selfsimilar spherical compression waves is given pointing out their fundamental importance for the gas dynamics of inertial confinement fusion. Strong blast waves, various forms of isentropic compression waves, imploding shock waves and the solution for non-isentropic collapsing hollow spheres are included. A classification is given in terms of six singular points which characterise the different solutions and the relations between them. The presentation closely follows Guderley's original work on imploding shock waves

  14. Fractal image compression

    NASA Technical Reports Server (NTRS)

    Barnsley, Michael F.; Sloan, Alan D.

    1989-01-01

    Fractals are geometric or data structures which do not simplify under magnification. Fractal Image Compression is a technique which associates a fractal to an image. On the one hand, the fractal can be described in terms of a few succinct rules, while on the other, the fractal contains much or all of the image information. Since the rules are described with less bits of data than the image, compression results. Data compression with fractals is an approach to reach high compression ratios for large data streams related to images. The high compression ratios are attained at a cost of large amounts of computation. Both lossless and lossy modes are supported by the technique. The technique is stable in that small errors in codes lead to small errors in image data. Applications to the NASA mission are discussed.

  15. Weekly Log Record Sort (WLSORT).

    ERIC Educational Resources Information Center

    Foote, Thomas

    Computer routines to sort the weekly log records submitted by teachers participating in the Southwest Regional Laboratory's communications skills monitoring program are described. Written in Univac FORTRAN V, Weekly Log Record Sort (WLSORT) sorts log records on magnetic tape to enable subsequent computer programs to interpret the input data by…

  16. Pregnancy Calendar: A Week-by-Week Guide

    MedlinePlus

    ... 42 weeks from the first day of their mom's LMP and only a small percentage of women actually deliver on their due date. Will you find out the sex of your baby before birth? Another common term ...

  17. Aerodynamics inside a rapid compression machine

    SciTech Connect

    Mittal, Gaurav; Sung, Chih-Jen

    2006-04-15

    The aerodynamics inside a rapid compression machine after the end of compression is investigated using planar laser-induced fluorescence (PLIF) of acetone. To study the effect of reaction chamber configuration on the resulting aerodynamics and temperature field, experiments are conducted and compared using a creviced piston and a flat piston under varying conditions. Results show that the flat piston design leads to significant mixing of the cold vortex with the hot core region, which causes alternate hot and cold regions inside the combustion chamber. At higher pressures, the effect of the vortex is reduced. The creviced piston head configuration is demonstrated to result in drastic reduction of the effect of the vortex. Experimental conditions are also simulated using the Star-CD computational fluid dynamics package. Computed results closely match with experimental observation. Numerical results indicate that with a flat piston design, gas velocity after compression is very high and the core region shrinks quickly due to rapid entrainment of cold gases. Whereas, for a creviced piston head design, gas velocity after compression is significantly lower and the core region remains unaffected for a long duration. As a consequence, for the flat piston, adiabatic core assumption can significantly overpredict the maximum temperature after the end of compression. For the creviced piston, the adiabatic core assumption is found to be valid even up to 100 ms after compression. This work therefore experimentally and numerically substantiates the importance of piston head design for achieving a homogeneous core region inside a rapid compression machine. (author)

  18. EEG data compression techniques.

    PubMed

    Antoniol, G; Tonella, P

    1997-02-01

    In this paper, electroencephalograph (EEG) and Holter EEG data compression techniques which allow perfect reconstruction of the recorded waveform from the compressed one are presented and discussed. Data compression permits one to achieve significant reduction in the space required to store signals and in transmission time. The Huffman coding technique in conjunction with derivative computation reaches high compression ratios (on average 49% on Holter and 58% on EEG signals) with low computational complexity. By exploiting this result a simple and fast encoder/decoder scheme capable of real-time performance on a PC was implemented. This simple technique is compared with other predictive transformations, vector quantization, discrete cosine transform (DCT), and repetition count compression methods. Finally, it is shown that the adoption of a collapsed Huffman tree for the encoding/decoding operations allows one to choose the maximum codeword length without significantly affecting the compression ratio. Therefore, low cost commercial microcontrollers and storage devices can be effectively used to store long Holter EEG's in a compressed format. PMID:9214790

  19. Boson core compressibility

    NASA Astrophysics Data System (ADS)

    Khorramzadeh, Y.; Lin, Fei; Scarola, V. W.

    2012-04-01

    Strongly interacting atoms trapped in optical lattices can be used to explore phase diagrams of Hubbard models. Spatial inhomogeneity due to trapping typically obscures distinguishing observables. We propose that measures using boson double occupancy avoid trapping effects to reveal two key correlation functions. We define a boson core compressibility and core superfluid stiffness in terms of double occupancy. We use quantum Monte Carlo on the Bose-Hubbard model to empirically show that these quantities intrinsically eliminate edge effects to reveal correlations near the trap center. The boson core compressibility offers a generally applicable tool that can be used to experimentally map out phase transitions between compressible and incompressible states.

  20. Local compressibilities in crystals

    NASA Astrophysics Data System (ADS)

    Martín Pendás, A.; Costales, Aurora; Blanco, M. A.; Recio, J. M.; Luaña, Víctor

    2000-12-01

    An application of the atoms in molecules theory to the partitioning of static thermodynamic properties in condensed systems is presented. Attention is focused on the definition and the behavior of atomic compressibilities. Inverses of bulk moduli are found to be simple weighted averages of atomic compressibilities. Two kinds of systems are investigated as examples: four related oxide spinels and the alkali halide family. Our analyses show that the puzzling constancy of the bulk moduli of these spinels is a consequence of the value of the compressibility of an oxide ion. A functional dependence between ionic bulk moduli and ionic volume is also proposed.

  1. Ramp Compression Experiments - a Sensitivity Study

    SciTech Connect

    Bastea, M; Reisman, D

    2007-02-26

    We present the first sensitivity study of the material isentropes extracted from ramp compression experiments. We perform hydrodynamic simulations of representative experimental geometries associated with ramp compression experiments and discuss the major factors determining the accuracy of the equation of state information extracted from such data. In conclusion, we analyzed both qualitatively and quantitatively the major experimental factors that determine the accuracy of equations of state extracted from ramp compression experiments. Since in actual experiments essentially all the effects discussed here will compound, factoring out individual signatures and magnitudes, as done in the present work, is especially important. This study should provide some guidance for the effective design and analysis of ramp compression experiments, as well as for further improvements of ramp generators performance.

  2. Compressibility Effects in Aeronautical Engineering

    NASA Technical Reports Server (NTRS)

    Stack, John

    1941-01-01

    Compressible-flow research, while a relatively new field in aeronautics, is very old, dating back almost to the development of the first firearm. Over the last hundred years, researches have been conducted in the ballistics field, but these results have been of practically no use in aeronautical engineering because the phenomena that have been studied have been the more or less steady supersonic condition of flow. Some work that has been done in connection with steam turbines, particularly nozzle studies, has been of value, In general, however, understanding of compressible-flow phenomena has been very incomplete and permitted no real basis for the solution of aeronautical engineering problems in which.the flow is likely to be unsteady because regions of both subsonic and supersonic speeds may occur. In the early phases of the development of the airplane, speeds were so low that the effects of compressibility could be justifiably ignored. During the last war and immediately after, however, propellers exhibited losses in efficiency as the tip speeds approached the speed of sound, and the first experiments of an aeronautical nature were therefore conducted with propellers. Results of these experiments indicated serious losses of efficiency, but aeronautical engineers were not seriously concerned at the time became it was generally possible. to design propellers with quite low tip. speeds. With the development of new engines having increased power and rotational speeds, however, the problems became of increasing importance.

  3. Military Data Compression Standard

    NASA Astrophysics Data System (ADS)

    Winterbauer, C. E.

    1982-07-01

    A facsimile interoperability data compression standard is being adopted by the U.S. Department of Defense and other North Atlantic Treaty Organization (NATO) countries. This algorithm has been shown to perform quite well in a noisy communication channel.

  4. Compressive optical image encryption.

    PubMed

    Li, Jun; Sheng Li, Jiao; Yang Pan, Yang; Li, Rong

    2015-01-01

    An optical image encryption technique based on compressive sensing using fully optical means has been proposed. An object image is first encrypted to a white-sense stationary noise pattern using a double random phase encoding (DRPE) method in a Mach-Zehnder interferometer. Then, the encrypted image is highly compressed to a signal using single-pixel compressive holographic imaging in the optical domain. At the receiving terminal, the encrypted image is reconstructed well via compressive sensing theory, and the original image can be decrypted with three reconstructed holograms and the correct keys. The numerical simulations show that the method is effective and suitable for optical image security transmission in future all-optical networks because of the ability of completely optical implementation and substantially smaller hologram data volume. PMID:25992946

  5. Focus on Compression Stockings

    MedlinePlus

    ... sion apparel is used to prevent or control edema The post-thrombotic syndrome (PTS) is a complication ( ... complication. abdomen. This swelling is referred to as edema. If you have edema, compression therapy may be ...

  6. Compressive Optical Image Encryption

    PubMed Central

    Li, Jun; Sheng Li, Jiao; Yang Pan, Yang; Li, Rong

    2015-01-01

    An optical image encryption technique based on compressive sensing using fully optical means has been proposed. An object image is first encrypted to a white-sense stationary noise pattern using a double random phase encoding (DRPE) method in a Mach-Zehnder interferometer. Then, the encrypted image is highly compressed to a signal using single-pixel compressive holographic imaging in the optical domain. At the receiving terminal, the encrypted image is reconstructed well via compressive sensing theory, and the original image can be decrypted with three reconstructed holograms and the correct keys. The numerical simulations show that the method is effective and suitable for optical image security transmission in future all-optical networks because of the ability of completely optical implementation and substantially smaller hologram data volume. PMID:25992946

  7. Compressible Astrophysics Simulation Code

    Energy Science and Technology Software Center (ESTSC)

    2007-07-18

    This is an astrophysics simulation code involving a radiation diffusion module developed at LLNL coupled to compressible hydrodynamics and adaptive mesh infrastructure developed at LBNL. One intended application is to neutrino diffusion in core collapse supernovae.

  8. Similarity by compression.

    PubMed

    Melville, James L; Riley, Jenna F; Hirst, Jonathan D

    2007-01-01

    We present a simple and effective method for similarity searching in virtual high-throughput screening, requiring only a string-based representation of the molecules (e.g., SMILES) and standard compression software, available on all modern desktop computers. This method utilizes the normalized compression distance, an approximation of the normalized information distance, based on the concept of Kolmogorov complexity. On representative data sets, we demonstrate that compression-based similarity searching can outperform standard similarity searching protocols, exemplified by the Tanimoto coefficient combined with a binary fingerprint representation and data fusion. Software to carry out compression-based similarity is available from our Web site at http://comp.chem.nottingham.ac.uk/download/zippity. PMID:17238245

  9. Image compression technique

    DOEpatents

    Fu, Chi-Yung; Petrich, Loren I.

    1997-01-01

    An image is compressed by identifying edge pixels of the image; creating a filled edge array of pixels each of the pixels in the filled edge array which corresponds to an edge pixel having a value equal to the value of a pixel of the image array selected in response to the edge pixel, and each of the pixels in the filled edge array which does not correspond to an edge pixel having a value which is a weighted average of the values of surrounding pixels in the filled edge array which do correspond to edge pixels; and subtracting the filled edge array from the image array to create a difference array. The edge file and the difference array are then separately compressed and transmitted or stored. The original image is later reconstructed by creating a preliminary array in response to the received edge file, and adding the preliminary array to the received difference array. Filling is accomplished by solving Laplace's equation using a multi-grid technique. Contour and difference file coding techniques also are described. The techniques can be used in a method for processing a plurality of images by selecting a respective compression approach for each image, compressing each of the images according to the compression approach selected, and transmitting each of the images as compressed, in correspondence with an indication of the approach selected for the image.

  10. Image compression technique

    DOEpatents

    Fu, C.Y.; Petrich, L.I.

    1997-03-25

    An image is compressed by identifying edge pixels of the image; creating a filled edge array of pixels each of the pixels in the filled edge array which corresponds to an edge pixel having a value equal to the value of a pixel of the image array selected in response to the edge pixel, and each of the pixels in the filled edge array which does not correspond to an edge pixel having a value which is a weighted average of the values of surrounding pixels in the filled edge array which do correspond to edge pixels; and subtracting the filled edge array from the image array to create a difference array. The edge file and the difference array are then separately compressed and transmitted or stored. The original image is later reconstructed by creating a preliminary array in response to the received edge file, and adding the preliminary array to the received difference array. Filling is accomplished by solving Laplace`s equation using a multi-grid technique. Contour and difference file coding techniques also are described. The techniques can be used in a method for processing a plurality of images by selecting a respective compression approach for each image, compressing each of the images according to the compression approach selected, and transmitting each of the images as compressed, in correspondence with an indication of the approach selected for the image. 16 figs.

  11. Alternative Compression Garments

    NASA Technical Reports Server (NTRS)

    Stenger, M. B.; Lee, S. M. C.; Ribeiro, L. C.; Brown, A. K.; Westby, C. M.; Platts, S. H.

    2011-01-01

    Orthostatic intolerance after spaceflight is still an issue for astronauts as no in-flight countermeasure has been 100% effective. Future anti-gravity suits (AGS) may be similar to the Shuttle era inflatable AGS or may be a mechanical compression device like the Russian Kentavr. We have evaluated the above garments as well as elastic, gradient compression garments of varying magnitude and determined that breast-high elastic compression garments may be a suitable replacement to the current AGS. This new garment should be more comfortable than the AGS, easy to don and doff, and as effective a countermeasure to orthostatic intolerance. Furthermore, these new compression garments could be worn for several days after space flight as necessary if symptoms persisted. We conducted two studies to evaluate elastic, gradient compression garments. The purpose of these studies was to evaluate the comfort and efficacy of an alternative compression garment (ACG) immediately after actual space flight and 6 degree head-down tilt bed rest as a model of space flight, and to determine if they would impact recovery if worn for up to three days after bed rest.

  12. Intelligent bandwith compression

    NASA Astrophysics Data System (ADS)

    Tseng, D. Y.; Bullock, B. L.; Olin, K. E.; Kandt, R. K.; Olsen, J. D.

    1980-02-01

    The feasibility of a 1000:1 bandwidth compression ratio for image transmission has been demonstrated using image-analysis algorithms and a rule-based controller. Such a high compression ratio was achieved by first analyzing scene content using auto-cueing and feature-extraction algorithms, and then transmitting only the pertinent information consistent with mission requirements. A rule-based controller directs the flow of analysis and performs priority allocations on the extracted scene content. The reconstructed bandwidth-compressed image consists of an edge map of the scene background, with primary and secondary target windows embedded in the edge map. The bandwidth-compressed images are updated at a basic rate of 1 frame per second, with the high-priority target window updated at 7.5 frames per second. The scene-analysis algorithms used in this system together with the adaptive priority controller are described. Results of simulated 1000:1 band width-compressed images are presented. A video tape simulation of the Intelligent Bandwidth Compression system has been produced using a sequence of video input from the data base.

  13. Micromechanics of composite laminate compression failures

    NASA Technical Reports Server (NTRS)

    Guynn, E. Gail; Bradley, Walter L.

    1988-01-01

    The purpose of this annual progress report is to summarize the work effort and results accomplished from July 1987 through July 1988 on NASA Research Grant NAG1-659 entitled Micromechanics of Composite Laminate Compressive Failure. The report contains: (1) the objective of the proposed research, (2) the summary of accomplishments, (3) a more extensive review of compression literature, (4) the planned material (and corresponding properties) received to date, (5) the results for three possible specimen geometries, experimental procedures planned, and current status of the experiments, and (6) the work planned for the next contract year.

  14. 10 Days or 10 Weeks: Immersion Programs That Work.

    ERIC Educational Resources Information Center

    Troiani, Elisa A.

    The foreign language faculty at College of Saint Scholastica Minnesota) developed and implemented 10-day Spanish and French immersion programs based on Peace Corps methodology as a means of affording students time for intensive study of those languages, improving students' fluency, and instituting a change in teaching methodology. The first…

  15. [Seventh National Population Week in Rwanda, 1993].

    PubMed

    Munyanziza, B

    1993-08-01

    The 1993 National Population Week opened in the commune of Rutare on August 2 and ended in Gikongoro in the commune of Rwamiko on August 6. Its goal was to sensitize all levels of the population to Rwanda's demographic problems through an IEC (information, education, communication) program while respecting the individual liberty, and the moral and religious beliefs of couples. On the first day of the population education campaign, the mayors of each commune along with its elite presided over a meeting to discuss implementation of the campaign, the sociodemographic situation at the commune level (especially at the household level), and the importance of family planning in family health. During August 2-5 at the commune level, the communal elite and the abakangurambagas presided over sensitization meetings, conference-debates, educational discussions, home visits, theatrical sessions, songs and dances, orientation to health centers, and recruitment of family planning acceptors. On the last day, development technicians working in the commune, teachers, students, religious leaders, abakangurambagas, political party leaders, and mass media journalists, all of whom took part in the week's activities, met at the communal office to evaluate the week's activities and to amass resolutions and recommendations. The mayor closed the 1993 edition of the National Population Week after the evaluation. PMID:12287364

  16. The compression of spheres coated with an aqueous ethylcellulose dispersion.

    PubMed

    Miller, R A; Leung, E M; Oates, R J

    1999-04-01

    Tablets were compressed from commercial samples of Sugar Spheres NF, Sucrose NF, Corn Starch NF, as well as ground spheres and a physical mixture of ground sucrose plus cornstarch. Additional tablets were compressed from spheres that had been coated with a water-soluble cellulosic polymer solution followed by an aqueous ethylcellulose dispersion. Tableting parameters measured "in-die" included work of compression, peak offset time, tablet density, and Young's modulus. Following ejection, tensile strength was determined under diametrical loading. Dissolution of a marker contained in the water-soluble layer was determined for both compressed and uncompressed spheres. Porosities at peak pressure and peak offset times or tensile strength as functions of peak pressure did not differ between tablets compressed from pristine spheres or from ground spheres. Tablets compressed from spheres had higher values for porosity, tensile strength, and peak offset time than those compressed from sucrose or the sucrose: starch mixture. Values for work of compression were higher for tablets compressed from pristine spheres or from starch. This was attributed to the work required for particle deformation and for breaking of the spheres. The greatest elastic recovery during decompression was observed for tablets compressed from pristine spheres or starch. More brittle behavior was observed for tablets compressed from sucrose or the sucrose: starch mixture. Tablets compressed from ground spheres were more brittle than those compressed from the pristine spheres, indicating an effect due to grinding. Most mechanical properties of tablets compressed from the coated spheres were comparable to those of tablets compressed from uncoated spheres. An exception was diametric strain for tablets compressed from spheres coated with the aqueous ethylcellulose dispersion. These values increased since the plasticized ethylcellulose allowed greater distortion of the tablet before failure occurred. The dye

  17. Wavelet compression of medical imagery.

    PubMed

    Reiter, E

    1996-01-01

    Wavelet compression is a transform-based compression technique recently shown to provide diagnostic-quality images at compression ratios as great as 30:1. Based on a recently developed field of applied mathematics, wavelet compression has found success in compression applications from digital fingerprints to seismic data. The underlying strength of the method is attributable in large part to the efficient representation of image data by the wavelet transform. This efficient or sparse representation forms the basis for high-quality image compression by providing subsequent steps of the compression scheme with data likely to result in long runs of zero. These long runs of zero in turn compress very efficiently, allowing wavelet compression to deliver substantially better performance than existing Fourier-based methods. Although the lack of standardization has historically been an impediment to widespread adoption of wavelet compression, this situation may begin to change as the operational benefits of the technology become better known. PMID:10165355

  18. Compression-sensitive magnetic resonance elastography

    NASA Astrophysics Data System (ADS)

    Hirsch, Sebastian; Beyer, Frauke; Guo, Jing; Papazoglou, Sebastian; Tzschaetzsch, Heiko; Braun, Juergen; Sack, Ingolf

    2013-08-01

    Magnetic resonance elastography (MRE) quantifies the shear modulus of biological tissue to detect disease. Complementary to the shear elastic properties of tissue, the compression modulus may be a clinically useful biomarker because it is sensitive to tissue pressure and poromechanical interactions. In this work, we analyze the capability of MRE to measure volumetric strain and the dynamic bulk modulus (P-wave modulus) at a harmonic drive frequency commonly used in shear-wave-based MRE. Gel phantoms with various densities were created by introducing CO2-filled cavities to establish a compressible effective medium. The dependence of the effective medium's bulk modulus on phantom density was investigated via static compression tests, which confirmed theoretical predictions. The P-wave modulus of three compressible phantoms was calculated from volumetric strain measured by 3D wave-field MRE at 50 Hz drive frequency. The results demonstrate the MRE-derived volumetric strain and P-wave modulus to be sensitive to the compression properties of effective media. Since the reconstruction of the P-wave modulus requires third-order derivatives, noise remains critical, and P-wave moduli are systematically underestimated. Focusing on relative changes in the effective bulk modulus of tissue, compression-sensitive MRE may be useful for the noninvasive detection of diseases involving pathological pressure alterations such as hepatic hypertension or hydrocephalus.

  19. Lossless compression of instrumentation data. Final report

    SciTech Connect

    Stearns, S.D.

    1995-11-01

    This is our final report on Sandia National Laboratories Laboratory- Directed Research and Development (LDRD) project 3517.070. Its purpose has been to investigate lossless compression of digital waveform and image data, particularly the types of instrumentation data generated and processed at Sandia Labs. The three-year project period ran from October 1992 through September 1995. This report begins with a descriptive overview of data compression, with and without loss, followed by a summary of the activities on the Sandia project, including research at several universities and the development of waveform compression software. Persons who participated in the project are also listed. The next part of the report contains a general discussion of the principles of lossless compression. Two basic compression stages, decorrelation and entropy coding, are described and discussed. An example of seismic data compression is included. Finally, there is a bibliography of published research. Taken together, the published papers contain the details of most of the work and accomplishments on the project. This final report is primarily an overview, without the technical details and results found in the publications listed in the bibliography.

  20. Compression-sensitive magnetic resonance elastography.

    PubMed

    Hirsch, Sebastian; Beyer, Frauke; Guo, Jing; Papazoglou, Sebastian; Tzschaetzsch, Heiko; Braun, Juergen; Sack, Ingolf

    2013-08-01

    Magnetic resonance elastography (MRE) quantifies the shear modulus of biological tissue to detect disease. Complementary to the shear elastic properties of tissue, the compression modulus may be a clinically useful biomarker because it is sensitive to tissue pressure and poromechanical interactions. In this work, we analyze the capability of MRE to measure volumetric strain and the dynamic bulk modulus (P-wave modulus) at a harmonic drive frequency commonly used in shear-wave-based MRE. Gel phantoms with various densities were created by introducing CO2-filled cavities to establish a compressible effective medium. The dependence of the effective medium's bulk modulus on phantom density was investigated via static compression tests, which confirmed theoretical predictions. The P-wave modulus of three compressible phantoms was calculated from volumetric strain measured by 3D wave-field MRE at 50 Hz drive frequency. The results demonstrate the MRE-derived volumetric strain and P-wave modulus to be sensitive to the compression properties of effective media. Since the reconstruction of the P-wave modulus requires third-order derivatives, noise remains critical, and P-wave moduli are systematically underestimated. Focusing on relative changes in the effective bulk modulus of tissue, compression-sensitive MRE may be useful for the noninvasive detection of diseases involving pathological pressure alterations such as hepatic hypertension or hydrocephalus. PMID:23852144

  1. Transverse Compression of Tendons.

    PubMed

    Samuel Salisbury, S T; Paul Buckley, C; Zavatsky, Amy B

    2016-04-01

    A study was made of the deformation of tendons when compressed transverse to the fiber-aligned axis. Bovine digital extensor tendons were compression tested between flat rigid plates. The methods included: in situ image-based measurement of tendon cross-sectional shapes, after preconditioning but immediately prior to testing; multiple constant-load creep/recovery tests applied to each tendon at increasing loads; and measurements of the resulting tendon displacements in both transverse directions. In these tests, friction resisted axial stretch of the tendon during compression, giving approximately plane-strain conditions. This, together with the assumption of a form of anisotropic hyperelastic constitutive model proposed previously for tendon, justified modeling the isochronal response of tendon as that of an isotropic, slightly compressible, neo-Hookean solid. Inverse analysis, using finite-element (FE) simulations of the experiments and 10 s isochronal creep displacement data, gave values for Young's modulus and Poisson's ratio of this solid of 0.31 MPa and 0.49, respectively, for an idealized tendon shape and averaged data for all the tendons and E = 0.14 and 0.10 MPa for two specific tendons using their actual measured geometry. The compression load versus displacement curves, as measured and as simulated, showed varying degrees of stiffening with increasing load. This can be attributed mostly to geometrical changes in tendon cross section under load, varying according to the initial 3D shape of the tendon. PMID:26833218

  2. Intelligent bandwidth compression

    NASA Astrophysics Data System (ADS)

    Tseng, D. Y.; Bullock, B. L.; Olin, K. E.; Kandt, R. K.; Olsen, J. D.

    1980-02-01

    The feasibility of a 1000:1 bandwidth compression ratio for image transmission has been demonstrated using image-analysis algorithms and a rule-based controller. Such a high compression ratio was achieved by first analyzing scene content using auto-cueing and feature-extraction algorithms, and then transmitting only the pertinent information consistent with mission requirements. A rule-based controller directs the flow of analysis and performs priority allocations on the extracted scene content. The reconstructed bandwidth-compressed image consists of an edge map of the scene background, with primary and secondary target windows embedded in the edge map. The bandwidth-compressed images are updated at a basic rate of 1 frame per second, with the high-priority target window updated at 7.5 frames per second. The scene-analysis algorithms used in this system together with the adaptive priority controller are described. Results of simulated 1000:1 bandwidth-compressed images are presented.

  3. Compressible Flow Toolbox

    NASA Technical Reports Server (NTRS)

    Melcher, Kevin J.

    2006-01-01

    The Compressible Flow Toolbox is primarily a MATLAB-language implementation of a set of algorithms that solve approximately 280 linear and nonlinear classical equations for compressible flow. The toolbox is useful for analysis of one-dimensional steady flow with either constant entropy, friction, heat transfer, or Mach number greater than 1. The toolbox also contains algorithms for comparing and validating the equation-solving algorithms against solutions previously published in open literature. The classical equations solved by the Compressible Flow Toolbox are as follows: The isentropic-flow equations, The Fanno flow equations (pertaining to flow of an ideal gas in a pipe with friction), The Rayleigh flow equations (pertaining to frictionless flow of an ideal gas, with heat transfer, in a pipe of constant cross section), The normal-shock equations, The oblique-shock equations, and The expansion equations.

  4. Isentropic Compression of Argon

    SciTech Connect

    H. Oona; J.C. Solem; L.R. Veeser, C.A. Ekdahl; P.J. Rodriquez; S.M. Younger; W. Lewis; W.D. Turley

    1997-08-01

    We are studying the transition of argon from an insulator to a conductor by compressing the frozen gas isentropically to pressures at which neighboring atomic orbitals overlap sufficiently to allow some electron motion between atoms. Argon and the other rare gases have closed electron shells and therefore remain montomic, even when they solidify. Their simple structure makes it likely that any measured change in conductivity is due to changes in the atomic structure, not in molecular configuration. As the crystal is compressed the band gap closes, allowing increased conductivity. We have begun research to determine the conductivity at high pressures, and it is our intention to determine the compression at which the crystal becomes a metal.

  5. The compressible mixing layer

    NASA Technical Reports Server (NTRS)

    Vandromme, Dany; Haminh, Hieu

    1991-01-01

    The capability of turbulence modeling correctly to handle natural unsteadiness appearing in compressible turbulent flows is investigated. Physical aspects linked to the unsteadiness problem and the role of various flow parameters are analyzed. It is found that unsteady turbulent flows can be simulated by dividing these motions into an 'organized' part for which equations of motion are solved and a remaining 'incoherent' part represented by a turbulence model. Two-equation turbulence models and second-order turbulence models can yield reasonable results. For specific compressible unsteady turbulent flow, graphic presentations of different quantities may reveal complementary physical features. Strong compression zones are observed in rapid flow parts but shocklets do not yet occur.

  6. Envera Variable Compression Ratio Engine

    SciTech Connect

    Charles Mendler

    2011-03-15

    Aggressive engine downsizing, variable compression ratio and use of the Atkinson cycle are being combined to improve fuel economy by up to 40 percent relative to port fuel injected gasoline engines, while maintaining full engine power. Approach Engine downsizing is viewed by US and foreign automobile manufacturers as one of the best options for improving fuel economy. While this strategy has already demonstrated a degree of success, downsizing and fuel economy gains are currently limited. With new variable compression ratio technology however, the degree of engine downsizing and fuel economy improvement can be greatly increased. A small variable compression ratio (VCR) engine has the potential to return significantly higher vehicle fuel economy while also providing high power. Affordability and potential for near term commercialization are key attributes of the Envera VCR engine. VCR Technology To meet torque and power requirements, a smaller engine needs to do more work per stroke. This is typically accomplished by boosting the incoming charge with either a turbo or supercharger so that more energy is present in the cylinder per stroke to do the work. With current production engines the degree of engine boosting (which correlates to downsizing) is limited by detonation (combustion knock) at high boost levels. Additionally, the turbo or supercharger needs to be responsive and efficient while providing the needed boost. VCR technology eliminates the limitation of engine knock at high load levels by reducing compression ratio to {approx}9:1 (or whatever level is appropriate) when high boost pressures are needed. By reducing the compression ratio during high load demand periods there is increased volume in the cylinder at top dead center (TDC) which allows more charge (or energy) to be present in the cylinder without increasing the peak pressure. Cylinder pressure is thus kept below the level at which the engine would begin to knock. When loads on the engine are low

  7. Adult Learners' Week in Switzerland.

    ERIC Educational Resources Information Center

    Jermann, Ruth

    2002-01-01

    The slogan of International Adult Learners Week in Switzerland is "one hour a day for learning." Four goals of the lifelong learning agenda are government policies to promote access, public awareness campaigns, creation of public learning places, and development of networks for real and virtual learning. (SK)

  8. Portuguese Special Course: 12 Weeks.

    ERIC Educational Resources Information Center

    Defense Language Inst., Washington, DC.

    This 12-week course in beginning Portuguese comprises four volumes of student text (Lessons 1-55) and a fifth volume of Portuguese-English/English-Portuguese vocabulary. Lesson materials consist of basic dialogs with English translation, recombination dialogs, readings and comprehension questions, oral exercises, and in later units, additional…

  9. Thai 18-Week Course: Glossary.

    ERIC Educational Resources Information Center

    Defense Language Inst., Washington, DC.

    This glossary is part of the Defense Language Institute's 18-week "Short Course in Thai." Other course materials include six 10-lesson volumes and accompanying tape recordings together with an "Introduction to Thai Script." The course is designed to train native-English speakers to level 1, elementary proficiency in speaking, understanding, and…

  10. Isentropic compression of argon

    SciTech Connect

    Veeser, L.R.; Ekdahl, C.A.; Oona, H.

    1997-06-01

    The compression was done in an MC-1 flux compression (explosive) generator, in order to study the transition from an insulator to a conductor. Since conductivity signals were observed in all the experiments (except when the probe is removed), both the Teflon and the argon are becoming conductive. The conductivity could not be determined (Teflon insulation properties unknown), but it could be bounded as being {sigma}=1/{rho}{le}8({Omega}cm){sub -1}, because when the Teflon breaks down, the dielectric constant is reduced. The Teflon insulator problem remains, and other ways to better insulate the probe or to measure the conductivity without a probe is being sought.

  11. Orbiting dynamic compression laboratory

    NASA Technical Reports Server (NTRS)

    Ahrens, T. J.; Vreeland, T., Jr.; Kasiraj, P.; Frisch, B.

    1984-01-01

    In order to examine the feasibility of carrying out dynamic compression experiments on a space station, the possibility of using explosive gun launchers is studied. The question of whether powders of a refractory metal (molybdenum) and a metallic glass could be well considered by dynamic compression is examined. In both cases extremely good bonds are obtained between grains of metal and metallic glass at 180 and 80 kb, respectively. When the oxide surface is reduced and the dynamic consolidation is carried out in vacuum, in the case of molybdenum, tensile tests of the recovered samples demonstrated beneficial ultimate tensile strengths.

  12. Watermark Compression in Medical Image Watermarking Using Lempel-Ziv-Welch (LZW) Lossless Compression Technique.

    PubMed

    Badshah, Gran; Liew, Siau-Chuin; Zain, Jasni Mohd; Ali, Mushtaq

    2016-04-01

    In teleradiology, image contents may be altered due to noisy communication channels and hacker manipulation. Medical image data is very sensitive and can not tolerate any illegal change. Illegally changed image-based analysis could result in wrong medical decision. Digital watermarking technique can be used to authenticate images and detect as well as recover illegal changes made to teleradiology images. Watermarking of medical images with heavy payload watermarks causes image perceptual degradation. The image perceptual degradation directly affects medical diagnosis. To maintain the image perceptual and diagnostic qualities standard during watermarking, the watermark should be lossless compressed. This paper focuses on watermarking of ultrasound medical images with Lempel-Ziv-Welch (LZW) lossless-compressed watermarks. The watermark lossless compression reduces watermark payload without data loss. In this research work, watermark is the combination of defined region of interest (ROI) and image watermarking secret key. The performance of the LZW compression technique was compared with other conventional compression methods based on compression ratio. LZW was found better and used for watermark lossless compression in ultrasound medical images watermarking. Tabulated results show the watermark bits reduction, image watermarking with effective tamper detection and lossless recovery. PMID:26429361

  13. "Creative" Work Schedules.

    ERIC Educational Resources Information Center

    Blai, Boris

    Many creative or flexible work scheduling options are becoming available to the many working parents, students, handicapped persons, elderly individuals, and others who are either unable or unwilling to work a customary 40-hour work week. These options may be broadly categorized as either restructured or reduced work time options. The three main…

  14. Compress Your Files

    ERIC Educational Resources Information Center

    Branzburg, Jeffrey

    2005-01-01

    File compression enables data to be squeezed together, greatly reducing file size. Why would someone want to do this? Reducing file size enables the sending and receiving of files over the Internet more quickly, the ability to store more files on the hard drive, and the ability pack many related files into one archive (for example, all files…

  15. The Compressed Video Experience.

    ERIC Educational Resources Information Center

    Weber, John

    In the fall semester 1995, Southern Arkansas University- Magnolia (SAU-M) began a two semester trial delivering college classes via a compressed video link between SAU-M and its sister school Southern Arkansas University Tech (SAU-T) in Camden. As soon as the University began broadcasting and receiving classes, it was discovered that using the…

  16. Nonlinear Frequency Compression

    PubMed Central

    Scollie, Susan; Glista, Danielle; Seelisch, Andreas

    2013-01-01

    Frequency lowering technologies offer an alternative amplification solution for severe to profound high frequency hearing losses. While frequency lowering technologies may improve audibility of high frequency sounds, the very nature of this processing can affect the perceived sound quality. This article reports the results from two studies that investigated the impact of a nonlinear frequency compression (NFC) algorithm on perceived sound quality. In the first study, the cutoff frequency and compression ratio parameters of the NFC algorithm were varied, and their effect on the speech quality was measured subjectively with 12 normal hearing adults, 12 normal hearing children, 13 hearing impaired adults, and 9 hearing impaired children. In the second study, 12 normal hearing and 8 hearing impaired adult listeners rated the quality of speech in quiet, speech in noise, and music after processing with a different set of NFC parameters. Results showed that the cutoff frequency parameter had more impact on sound quality ratings than the compression ratio, and that the hearing impaired adults were more tolerant to increased frequency compression than normal hearing adults. No statistically significant differences were found in the sound quality ratings of speech-in-noise and music stimuli processed through various NFC settings by hearing impaired listeners. These findings suggest that there may be an acceptable range of NFC settings for hearing impaired individuals where sound quality is not adversely affected. These results may assist an Audiologist in clinical NFC hearing aid fittings for achieving a balance between high frequency audibility and sound quality. PMID:23539261

  17. Compression: Rent or own

    SciTech Connect

    Cahill, C.

    1997-07-01

    Historically, the decision to purchase or rent compression has been set as a corporate philosophy. As companies decentralize, there seems to be a shift away from corporate philosophy toward individual profit centers. This has led the decision to rent versus purchase to be looked at on a regional or project-by-project basis.

  18. Improved compression molding process

    NASA Technical Reports Server (NTRS)

    Heier, W. C.

    1967-01-01

    Modified compression molding process produces plastic molding compounds that are strong, homogeneous, free of residual stresses, and have improved ablative characteristics. The conventional method is modified by applying a vacuum to the mold during the molding cycle, using a volatile sink, and exercising precise control of the mold closure limits.

  19. Compressive rendering: a rendering application of compressed sensing.

    PubMed

    Sen, Pradeep; Darabi, Soheil

    2011-04-01

    Recently, there has been growing interest in compressed sensing (CS), the new theory that shows how a small set of linear measurements can be used to reconstruct a signal if it is sparse in a transform domain. Although CS has been applied to many problems in other fields, in computer graphics, it has only been used so far to accelerate the acquisition of light transport. In this paper, we propose a novel application of compressed sensing by using it to accelerate ray-traced rendering in a manner that exploits the sparsity of the final image in the wavelet basis. To do this, we raytrace only a subset of the pixel samples in the spatial domain and use a simple, greedy CS-based algorithm to estimate the wavelet transform of the image during rendering. Since the energy of the image is concentrated more compactly in the wavelet domain, less samples are required for a result of given quality than with conventional spatial-domain rendering. By taking the inverse wavelet transform of the result, we compute an accurate reconstruction of the desired final image. Our results show that our framework can achieve high-quality images with approximately 75 percent of the pixel samples using a nonadaptive sampling scheme. In addition, we also perform better than other algorithms that might be used to fill in the missing pixel data, such as interpolation or inpainting. Furthermore, since the algorithm works in image space, it is completely independent of scene complexity. PMID:21311092

  20. Astronomy Week in Madeira, Portugal

    NASA Astrophysics Data System (ADS)

    Augusto, P.; Sobrinho, J. L.

    2012-05-01

    The outreach programme Semanas da Astronomia (Astronomy Weeks) is held in late spring or summer on the island of Madeira, Portugal. This programme has been attracting enough interest to be mentioned in the regional press/TV/radio every year and is now, without doubt, the astronomical highlight of the year on Madeira. We believe that this programme is a good case study for showing how to attract the general public to astronomy in a small (population 250 000, area 900 km2) and fairly isolated place such as Madeira. Our Astronomy Weeks have been different each year and have so far included exhibitions, courses, talks, a forum, documentaries, observing sessions (some with blackouts), music and an astro party. These efforts may contribute towards putting Madeira on the map with respect to observational astronomy, and have also contributed to the planned installation of two observatories in the island.

  1. Preprototype Vapor Compression Distillation Subsystem development

    NASA Technical Reports Server (NTRS)

    Thompson, C. D.; Ellis, G. S.; Schubert, F. H.

    1981-01-01

    Vapor Compression Distillation (VCD) has evolved as the most promising approach to reclaim potable water from wastewater for future long-term manned space missions. Life Systems, Inc. (LSI), working with NASA, has developed a preprototype Vapor Compression Distillation Subsystem (VCDS) which processes wastewater at 1.4 kg/h. The preprototype unit weighs 143 kg, occupies a volume of 0.47 cu m, and will reclaim 96 percent of the available wastewater. This unit has been tested by LSI and is scheduled for further testing at NASA-JSC. This paper presents the preprototype VCDS design, configuration, performance data, test results and flight system projections.

  2. Unsteady Aerodynamics - Subsonic Compressible Inviscid Case

    NASA Technical Reports Server (NTRS)

    Balakrishnan, A. V.

    1999-01-01

    This paper presents a new analytical treatment of Unsteady Aerodynamics - the linear theory covering the subsonic compressible (inviscid) case - drawing on some recent work in Operator Theory and Functional Analysis. The specific new results are: (a) An existence and uniqueness proof for the Laplace transform version of the Possio integral equation as well as a new closed form solution approximation thereof. (b) A new representation for the time-domain solution of the subsonic compressible aerodynamic equations emphasizing in particular the role of the initial conditions.

  3. Six Week Slavery Novel Unit.

    ERIC Educational Resources Information Center

    Jones, Darolyn Lyn

    Developed in conjunction with a graduate course and used in classrooms with all types of learners, this paper presents a 6-week unit of study on slavery based on two adolescent novels--"NIGHTJOHN" by Gary Paulson and "My Name Is not Angelica" by Scott O'Dell. After a brief introduction to the unit, the paper presents the 14 activities of the unit:…

  4. Mosaic image compression

    NASA Astrophysics Data System (ADS)

    Chaudhari, Kapil A.; Reeves, Stanley J.

    2005-02-01

    Most consumer-level digital cameras use a color filter array to capture color mosaic data followed by demosaicking to obtain full-color images. However, many sophisticated demosaicking algorithms are too complex to implement on-board a camera. To use these algorithms, one must transfer the mosaic data from the camera to a computer without introducing compression losses that could generate artifacts in the demosaicked image. The memory required for losslessly stored mosaic images severely restricts the number of images that can be stored in the camera. Therefore, we need an algorithm to compress the original mosaic data losslessly so that it can later be transferred intact for demosaicking. We propose a new lossless compression technique for mosaic images in this paper. Ordinary image compression methods do not apply to mosaic images because of their non-canonical color sampling structure. Because standard compression methods such as JPEG, JPEG2000, etc. are already available in most digital cameras, we have chosen to build our algorithms using a standard method as a key part of the system. The algorithm begins by separating the mosaic image into 3 color (RGB) components. This is followed by an interpolation or down-sampling operation--depending on the particular variation of the algorithm--that makes all three components the same size. Using the three color components, we form a color image that is coded with JPEG. After appropriately reformatting the data, we calculate the residual between the original image and the coded image and then entropy-code the residual values corresponding to the mosaic data.

  5. Compression failure of angle-ply laminates

    NASA Technical Reports Server (NTRS)

    Peel, Larry D.; Hyer, Michael W.; Shuart, Mark J.

    1991-01-01

    The present work deals with modes and mechanisms of failure in compression of angle-ply laminates. Experimental results were obtained from 42 angle-ply IM7/8551-7a specimens with a lay-up of ((plus or minus theta)/(plus or minus theta)) sub 6s where theta, the off-axis angle, ranged from 0 degrees to 90 degrees. The results showed four failure modes, these modes being a function of off-axis angle. Failure modes include fiber compression, inplane transverse tension, inplane shear, and inplane transverse compression. Excessive interlaminar shear strain was also considered as an important mode of failure. At low off-axis angles, experimentally observed values were considerably lower than published strengths. It was determined that laminate imperfections in the form of layer waviness could be a major factor in reducing compression strength. Previously developed linear buckling and geometrically nonlinear theories were used, with modifications and enhancements, to examine the influence of layer waviness on compression response. The wavy layer is described by a wave amplitude and a wave length. Linear elastic stress-strain response is assumed. The geometrically nonlinear theory, in conjunction with the maximum stress failure criterion, was used to predict compression failure and failure modes for the angle-ply laminates. A range of wave length and amplitudes were used. It was found that for 0 less than or equal to theta less than or equal to 15 degrees failure was most likely due to fiber compression. For 15 degrees less than theta less than or equal to 35 degrees, failure was most likely due to inplane transverse tension. For 35 degrees less than theta less than or equal to 70 degrees, failure was most likely due to inplane shear. For theta less than 70 degrees, failure was most likely due to inplane transverse compression. The fiber compression and transverse tension failure modes depended more heavily on wave length than on wave amplitude. Thus using a single

  6. Microseismic source imaging in a compressed domain

    NASA Astrophysics Data System (ADS)

    Vera Rodriguez, Ismael; Sacchi, Mauricio D.

    2014-08-01

    Microseismic monitoring is an essential tool for the characterization of hydraulic fractures. Fast estimation of the parameters that define a microseismic event is relevant to understand and control fracture development. The amount of data contained in the microseismic records however, poses a challenge for fast continuous detection and evaluation of the microseismic source parameters. Work inspired by the emerging field of Compressive Sensing has showed that it is possible to evaluate source parameters in a compressed domain, thereby reducing processing time. This technique performs well in scenarios where the amplitudes of the signal are above the noise level, as is often the case in microseismic monitoring using downhole tools. This paper extends the idea of the compressed domain processing to scenarios of microseismic monitoring using surface arrays, where the signal amplitudes are commonly at the same level as, or below, the noise amplitudes. To achieve this, we resort to the use of an imaging operator, which has previously been found to produce better results in detection and location of microseismic events from surface arrays. The operator in our method is formed by full-waveform elastodynamic Green's functions that are band-limited by a source time function and represented in the frequency domain. Where full-waveform Green's functions are not available, ray tracing can also be used to compute the required Green's functions. Additionally, we introduce the concept of the compressed inverse, which derives directly from the compression of the migration operator using a random matrix. The described methodology reduces processing time at a cost of introducing distortions into the results. However, the amount of distortion can be managed by controlling the level of compression applied to the operator. Numerical experiments using synthetic and real data demonstrate the reductions in processing time that can be achieved and exemplify the process of selecting the

  7. Compression behavior of single-layer graphenes.

    PubMed

    Frank, Otakar; Tsoukleri, Georgia; Parthenios, John; Papagelis, Konstantinos; Riaz, Ibtsam; Jalil, Rashid; Novoselov, Kostya S; Galiotis, Costas

    2010-06-22

    Central to most applications involving monolayer graphenes is its mechanical response under various stress states. To date most of the work reported is of theoretical nature and refers to tension and compression loading of model graphenes. Most of the experimental work is indeed limited to the bending of single flakes in air and the stretching of flakes up to typically approximately 1% using plastic substrates. Recently we have shown that by employing a cantilever beam we can subject single graphenes to various degrees of axial compression. Here we extend this work much further by measuring in detail both stress uptake and compression buckling strain in single flakes of different geometries. In all cases the mechanical response is monitored by simultaneous Raman measurements through the shift of either the G or 2D phonons of graphene. Despite the infinitely small thickness of the monolayers, the results show that graphenes embedded in plastic beams exhibit remarkable compression buckling strains. For large length (l)-to-width (w) ratios (> or =0.2) the buckling strain is of the order of -0.5% to -0.6%. However, for l/w < 0.2 no failure is observed for strains even higher than -1%. Calculations based on classical Euler analysis show that the buckling strain enhancement provided by the polymer lateral support is more than 6 orders of magnitude compared to that of suspended graphene in air. PMID:20496881

  8. Temperature gradient formation while axial gas compression

    NASA Astrophysics Data System (ADS)

    Geyko, V. I.; Fisch, N. J.

    2015-11-01

    A spinning gas in equilibrium has a rotation-dependent heat capacity. However, as equilibrium is approached, such as after sudden heating, significant variations in temperature appear. Surprisingly, when fast axial compression or instantaneous gas heating occurs, the temperature does not grow homogeneously in radial direction, but instead has a gradient towards to the maximum of potential energy of external or self potential. The gradient monotonically grows with compression rate and the amplitude of the potential. The gradient builds up due to change of equilibrium density distribution, yet, not due to acoustic waves created by the compression. This result was checked in numerical simulations for particles in an external constant gravitational potential and also for rotating gas in the cylinder with perfect slip boundary conditions on the walls. This work was supported by the U.S. Defense Threat Reduction Agency, and by the NNSA SSAA Program through DOE Research Grant No. DE-FG52-08NA28553.

  9. PDF approach for compressible turbulent reacting flows

    NASA Technical Reports Server (NTRS)

    Hsu, A. T.; Tsai, Y.-L. P.; Raju, M. S.

    1993-01-01

    The objective of the present work is to develop a probability density function (pdf) turbulence model for compressible reacting flows for use with a CFD flow solver. The probability density function of the species mass fraction and enthalpy are obtained by solving a pdf evolution equation using a Monte Carlo scheme. The pdf solution procedure is coupled with a compressible CFD flow solver which provides the velocity and pressure fields. A modeled pdf equation for compressible flows, capable of capturing shock waves and suitable to the present coupling scheme, is proposed and tested. Convergence of the combined finite-volume Monte Carlo solution procedure is discussed, and an averaging procedure is developed to provide smooth Monte-Carlo solutions to ensure convergence. Two supersonic diffusion flames are studied using the proposed pdf model and the results are compared with experimental data; marked improvements over CFD solutions without pdf are observed. Preliminary applications of pdf to 3D flows are also reported.

  10. Longwave infrared compressive hyperspectral imager

    NASA Astrophysics Data System (ADS)

    Dupuis, Julia R.; Kirby, Michael; Cosofret, Bogdan R.

    2015-06-01

    Physical Sciences Inc. (PSI) is developing a longwave infrared (LWIR) compressive sensing hyperspectral imager (CS HSI) based on a single pixel architecture for standoff vapor phase plume detection. The sensor employs novel use of a high throughput stationary interferometer and a digital micromirror device (DMD) converted for LWIR operation in place of the traditional cooled LWIR focal plane array. The CS HSI represents a substantial cost reduction over the state of the art in LWIR HSI instruments. Radiometric improvements for using the DMD in the LWIR spectral range have been identified and implemented. In addition, CS measurement and sparsity bases specifically tailored to the CS HSI instrument and chemical plume imaging have been developed and validated using LWIR hyperspectral image streams of chemical plumes. These bases enable comparable statistics to detection based on uncompressed data. In this paper, we present a system model predicting the overall performance of the CS HSI system. Results from a breadboard build and test validating the system model are reported. In addition, the measurement and sparsity basis work demonstrating the plume detection on compressed hyperspectral images is presented.

  11. Design Point for a Spheromak Compression Experiment

    NASA Astrophysics Data System (ADS)

    Woodruff, Simon; Romero-Talamas, Carlos A.; O'Bryan, John; Stuber, James; Darpa Spheromak Team

    2015-11-01

    Two principal issues for the spheromak concept remain to be addressed experimentally: formation efficiency and confinement scaling. We are therefore developing a design point for a spheromak experiment that will be heated by adiabatic compression, utilizing the CORSICA and NIMROD codes as well as analytic modeling with target parameters R_initial =0.3m, R_final =0.1m, T_initial =0.2keV, T_final =1.8keV, n_initial =1019m-3 and n_final = 1021m-3, with radial convergence of C =3. This low convergence differentiates the concept from MTF with C =10 or more, since the plasma will be held in equilibrium throughout compression. We present results from CORSICA showing the placement of coils and passive structure to ensure stability during compression, and design of the capacitor bank needed to both form the target plasma and compress it. We specify target parameters for the compression in terms of plasma beta, formation efficiency and energy confinement. Work performed under DARPA grant N66001-14-1-4044.

  12. The New CCSDS Image Compression Recommendation

    NASA Technical Reports Server (NTRS)

    Yeh, Pen-Shu; Armbruster, Philippe; Kiely, Aaron; Masschelein, Bart; Moury, Gilles; Schaefer, Christoph

    2005-01-01

    The Consultative Committee for Space Data Systems (CCSDS) data compression working group has recently adopted a recommendation for image data compression, with a final release expected in 2005. The algorithm adopted in the recommendation consists of a two-dimensional discrete wavelet transform of the image, followed by progressive bit-plane coding of the transformed data. The algorithm can provide both lossless and lossy compression, and allows a user to directly control the compressed data volume or the fidelity with which the wavelet-transformed data can be reconstructed. The algorithm is suitable for both frame-based image data and scan-based sensor data, and has applications for near-Earth and deep-space missions. The standard will be accompanied by free software sources on a future web site. An Application-Specific Integrated Circuit (ASIC) implementation of the compressor is currently under development. This paper describes the compression algorithm along with the requirements that drove the selection of the algorithm. Performance results and comparisons with other compressors are given for a test set of space images.

  13. Ultrafast compression: past, present, and future

    NASA Astrophysics Data System (ADS)

    Armstrong, Michael

    2015-06-01

    In the nearly 20 years since the first sub-ps time resolution compression wave measurements, ultrafast compression experiments have progressed from simple demonstrations to robust discoveries of extreme phenomena spanning material plasticity, solid-solid phase transitions, and shock induced chemistry. At strain rates above 109 s-1, many usual assumptions about material response no longer apply - virtually every system investigated on sub-ns time scales exhibits phenomena which are unfamiliar to conventional intuition about compression waves. This diverse of range of phenomena reflects the fundamental complexity of dynamic material behavior, but it has also been a significant impediment to a full understanding of material compression. Nonetheless, ultrafast experiments afford a number of practical advantages, primarily related to scale. Using an inexpensive table-top laser, it is possible to obtain information on materials at extreme conditions with a low laser pulse energy and a high data rate. In this talk, I will briefly review the history of ultrafast compression, significant results, and future opportunities. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  14. Compressed Air/Vacuum Transportation Techniques

    NASA Astrophysics Data System (ADS)

    Guha, Shyamal

    2011-03-01

    General theory of compressed air/vacuum transportation will be presented. In this transportation, a vehicle (such as an automobile or a rail car) is powered either by compressed air or by air at near vacuum pressure. Four version of such transportation is feasible. In all versions, a ``c-shaped'' plastic or ceramic pipe lies buried a few inches under the ground surface. This pipe carries compressed air or air at near vacuum pressure. In type I transportation, a vehicle draws compressed air (or vacuum) from this buried pipe. Using turbine or reciprocating air cylinder, mechanical power is generated from compressed air (or from vacuum). This mechanical power transferred to the wheels of an automobile (or a rail car) drives the vehicle. In type II-IV transportation techniques, a horizontal force is generated inside the plastic (or ceramic) pipe. A set of vertical and horizontal steel bars is used to transmit this force to the automobile on the road (or to a rail car on rail track). The proposed transportation system has following merits: virtually accident free; highly energy efficient; pollution free and it will not contribute to carbon dioxide emission. Some developmental work on this transportation will be needed before it can be used by the traveling public. The entire transportation system could be computer controlled.

  15. Data Compression for Helioseismology

    NASA Astrophysics Data System (ADS)

    Löptien, Björn

    2015-10-01

    Efficient data compression will play an important role for several upcoming and planned space missions involving helioseismology, such as Solar Orbiter. Solar Orbiter, to be launched in October 2018, will be the next space mission involving helioseismology. The main characteristic of Solar Orbiter lies in its orbit. The spacecraft will have an inclined solar orbit, reaching a solar latitude of up to 33 deg. This will allow, for the first time, probing the solar poles using local helioseismology. In addition, combined observations of Solar Orbiter and another helioseismic instrument will be used to study the deep interior of the Sun using stereoscopic helioseismology. The Doppler velocity and continuum intensity images of the Sun required for helioseismology will be provided by the Polarimetric and Helioseismic Imager (PHI). Major constraints for helioseismology with Solar Orbiter are the low telemetry and the (probably) short observing time. In addition, helioseismology of the solar poles requires observations close to the solar limb, even from the inclined orbit of Solar Orbiter. This gives rise to systematic errors. In this thesis, I derived a first estimate of the impact of lossy data compression on helioseismology. I put special emphasis on the Solar Orbiter mission, but my results are applicable to other planned missions as well. First, I studied the performance of PHI for helioseismology. Based on simulations of solar surface convection and a model of the PHI instrument, I generated a six-hour time-series of synthetic Doppler velocity images with the same properties as expected for PHI. Here, I focused on the impact of the point spread function, the spacecraft jitter, and of the photon noise level. The derived power spectra of solar oscillations suggest that PHI will be suitable for helioseismology. The low telemetry of Solar Orbiter requires extensive compression of the helioseismic data obtained by PHI. I evaluated the influence of data compression using

  16. Acceptance Test Report for 241-U compressed air system

    SciTech Connect

    Freeman, R.D.

    1994-10-20

    This Acceptance Test Report (ATR) documents the results of acceptance testing of a newly upgraded compressed air system at 241-U Farm. The system was installed and the test successfully performed under work package 2W-92-01027.

  17. Digital cinema video compression

    NASA Astrophysics Data System (ADS)

    Husak, Walter

    2003-05-01

    The Motion Picture Industry began a transition from film based distribution and projection to digital distribution and projection several years ago. Digital delivery and presentation offers the prospect to increase the quality of the theatrical experience for the audience, reduce distribution costs to the distributors, and create new business opportunities for the theater owners and the studios. Digital Cinema also presents an opportunity to provide increased flexibility and security of the movies for the content owners and the theater operators. Distribution of content via electronic means to theaters is unlike any of the traditional applications for video compression. The transition from film-based media to electronic media represents a paradigm shift in video compression techniques and applications that will be discussed in this paper.

  18. Compressibility of solids

    NASA Technical Reports Server (NTRS)

    Vinet, P.; Ferrante, J.; Rose, J. H.; Smith, J. R.

    1987-01-01

    A universal form is proposed for the equation of state (EOS) of solids. Good agreement is found for a variety of test data. The form of the EOS is used to suggest a method of data analysis, which is applied to materials of geophysical interest. The isothermal bulk modulus is discussed as a function of the volume and of the pressure. The isothermal compression curves for materials of geophysical interest are examined.

  19. Variable Quality Compression of Fluid Dynamical Data Sets Using a 3D DCT Technique

    NASA Astrophysics Data System (ADS)

    Loddoch, A.; Schmalzl, J.

    2005-12-01

    In this work we present a data compression scheme that is especially suited for the compression of data sets resulting from computational fluid dynamics (CFD). By adopting the concept of the JPEG compression standard and extending the approach of Schmalzl (Schmalzl, J. Using standard image compression algorithms to store data from computational fluid dynamics. Computers and Geosciences, 29, 10211031, 2003) we employ a three-dimensional discrete cosine transform of the data. The resulting frequency components are rearranged, quantized and finally stored using Huffman-encoding and standard variable length integer codes. The compression ratio and also the introduced loss of accuracy can be adjusted by means of two compression parameters to give the desired compression profile. Using the proposed technique compression ratios of more than 60:1 are possible with an mean error of the compressed data of less than 0.1%.

  20. Learning random networks for compression of still and moving images

    NASA Technical Reports Server (NTRS)

    Gelenbe, Erol; Sungur, Mert; Cramer, Christopher

    1994-01-01

    Image compression for both still and moving images is an extremely important area of investigation, with numerous applications to videoconferencing, interactive education, home entertainment, and potential applications to earth observations, medical imaging, digital libraries, and many other areas. We describe work on a neural network methodology to compress/decompress still and moving images. We use the 'point-process' type neural network model which is closer to biophysical reality than standard models, and yet is mathematically much more tractable. We currently achieve compression ratios of the order of 120:1 for moving grey-level images, based on a combination of motion detection and compression. The observed signal-to-noise ratio varies from values above 25 to more than 35. The method is computationally fast so that compression and decompression can be carried out in real-time. It uses the adaptive capabilities of a set of neural networks so as to select varying compression ratios in real-time as a function of quality achieved. It also uses a motion detector which will avoid retransmitting portions of the image which have varied little from the previous frame. Further improvements can be achieved by using on-line learning during compression, and by appropriate compensation of nonlinearities in the compression/decompression scheme. We expect to go well beyond the 250:1 compression level for color images with good quality levels.

  1. The compressible adjoint equations in geodynamics: equations and numerical assessment

    NASA Astrophysics Data System (ADS)

    Ghelichkhan, Siavash; Bunge, Hans-Peter

    2016-04-01

    The adjoint method is a powerful means to obtain gradient information in a mantle convection model relative to past flow structure. While the adjoint equations in geodynamics have been derived for the conservation equations of mantle flow in their incompressible form, the applicability of this approximation to Earth is limited, because density increases by almost a factor of two from the surface to the Core Mantle Boundary. Here we introduce the compressible adjoint equations for the conservation equations in the anelastic-liquid approximation. Our derivation applies an operator formulation in Hilbert spaces, to connect to recent work in seismology (Fichtner et al (2006)) and geodynamics (Horbach et al (2014)), where the approach was used to derive the adjoint equations for the wave equation and incompressible mantle flow. We present numerical tests of the newly derived equations based on twin experiments, focusing on three simulations. A first, termed Compressible, assumes the compressible forward and adjoint equations, and represents the consistent means of including compressibility effects. A second, termed Mixed, applies the compressible forward equation, but ignores compressibility effects in the adjoint equations, where the incompressible equations are used instead. A third simulation, termed Incompressible, neglects compressibility effects entirely in the forward and adjoint equations relative to the reference twin. The compressible and mixed formulations successfully restore earlier mantle flow structure, while the incompressible formulation yields noticeable artifacts. Our results suggest the use of a compressible formulation, when applying the adjoint method to seismically derived mantle heterogeneity structure.

  2. Extracting Constitutive Stress-Strain Behavior of Microscopic Phases by Micropillar Compression

    SciTech Connect

    Williams, J. J.; Walters, Jennifer; Wang, Mingyue; Chawla, N.; Rohatgi, Aashish

    2013-02-01

    The manuscript describes how micropillar compression technique can be used to perform uniaxial compression tests within individual grains so as to generate local-scale constitutive behavior which, otherwise cannot be ascertained from the conventional macroscale compression test techniques. The manuscript uses steel and magnesium alloys as an example. A portion of the magnesium work was performed at PNNL.

  3. Dickinson High School. Career Awareness. Nine Week Mini-Unit.

    ERIC Educational Resources Information Center

    Boespflug, LeRoy R.

    This guide contains supportive materials for a nine-week mini-unit developed for and utilized within the framework of the tenth-grade required Career Awareness Class of Dickinson High School, North Dakota. The first section on work and the work ethic presents a career development glossary for career education and two essays on identifying the…

  4. Piston reciprocating compressed air engine

    SciTech Connect

    Cestero, L.G.

    1987-03-24

    A compressed air engine is described comprising: (a). a reservoir of compressed air, (b). two power cylinders each containing a reciprocating piston connected to a crankshaft and flywheel, (c). a transfer cylinder which communicates with each power cylinder and the reservoir, and contains a reciprocating piston connected to the crankshaft, (d). valve means controlled by rotation of the crankshaft for supplying compressed air from the reservoir to each power cylinder and for exhausting compressed air from each power cylinder to the transfer cylinder, (e). valve means controlled by rotation of the crankshaft for supplying from the transfer cylinder to the reservoir compressed air supplied to the transfer cylinder on the exhaust strokes of the pistons of the power cylinders, and (f). an externally powered fan for assisting the exhaust of compressed air from each power cylinder to the transfer cylinder and from there to the compressed air reservoir.

  5. The Four Day School Week. Research Brief

    ERIC Educational Resources Information Center

    Muir, Mike

    2013-01-01

    Can four-day school weeks help districts save money? How do districts overcome the barriers of moving to a four-day week? What is the effect of a four-day week on students, staff and the community? This paper enumerates the benefits for students and teachers of four-day school weeks. Recommendations for implementation of a four-day week are also…

  6. Curriculum Characteristics of Time-Compressed Course in a U.S. Higher Education Institution

    ERIC Educational Resources Information Center

    Hyun, Eunsook; Kretovics, Mark; Crowe, Alicia

    2006-01-01

    The study explored characteristics of the curriculum practice of higher education faculty in the context of time-compressed (e.g., 5-6 weeks) courses as compared with regular term (15-16 weeks) courses. The researchers used open-ended questions on a web-based survey at a large doctoral-extensive university in a Midwestern state in the United…

  7. International magnetic pulse compression

    SciTech Connect

    Kirbie, H.C.; Newton, M.A.; Siemens, P.D.

    1991-04-01

    Although pulsed-power engineering traditionally has been practiced by a fairly small, close community in the areas of defense and energy research, it is becoming more common in high-power, high-energy commercial pursuits such as material processing and lasers. This paper is a synopsis of the Feb. 12--14, 1990 workshop on magnetic switching as it applies primarily to pulse compression (power transformation). During the course of the Workshop at Granlibakken, a great deal of information was amassed and a keen insight into both the problems and opportunities as to the use of this switching approach was developed. The segmented workshop format proved ideal for identifying key aspects affecting optimum performance in a variety of applications. Individual groups of experts addressed network and system modeling, magnetic materials, power conditioning, core cooling and dielectrics, and finally circuits and application. At the end, they came together to consolidate their input and formulate the workshop's conclusions, identifying roadblocks or suggesting research projects, particularly as they apply to magnetic switching's trump card -- its high-average-power-handling capability (at least on a burst-mode basis). The workshop was especially productive both in the quality and quantity of information transfer in an environment conducive to a free and open exchange of ideas. We will not delve into the organization proper of this meeting, rather we wish to commend to the interested reader this volume, which provides the definitive and most up-to-date compilation on the subject of magnetic pulse compression from underlying principles to current state of the art as well as the prognosis for the future of magnetic pulse compression as a consensus of the workshop's organizers and participants.

  8. Compression retaining piston

    SciTech Connect

    Quaglino, A.V. Jr.

    1987-06-16

    A piston apparatus is described for maintaining compression between the piston wall and the cylinder wall, that comprises the following: a generally cylindrical piston body, including: a head portion defining the forward end of the body; and a continuous side wall portion extending rearward from the head portion; a means for lubricating and preventing compression loss between the side wall portion and the cylinder wall, including an annular recessed area in the continuous side wall portion for receiving a quantity of fluid lubricant in fluid engagement between the wall of the recessed and the wall of the cylinder; a first and second resilient, elastomeric, heat resistant rings positioned in grooves along the wall of the continuous side wall portion, above and below the annular recessed area. Each ring engages the cylinder wall to reduce loss of lubricant within the recessed area during operation of the piston; a first pump means for providing fluid lubricant to engine components other than the pistons; and a second pump means provides fluid lubricant to the recessed area in the continuous side wall portion of the piston. The first and second pump means obtains lubricant from a common source, and the second pump means including a flow line supplies oil from a predetermined level above the level of oil provided to the first pump means. This is so that should the oil level to the second pump means fall below the predetermined level, the loss of oil to the recessed area in the continuous side wall portion of the piston would result in loss of compression and shut down of the engine.

  9. International magnetic pulse compression

    NASA Astrophysics Data System (ADS)

    Kirbie, H. C.; Newton, M. A.; Siemens, P. D.

    1991-04-01

    Although pulsed-power engineering traditionally has been practiced by a fairly small, close community in the areas of defense and energy research, it is becoming more common in high-power, high-energy commercial pursuits such as material processing and lasers. This paper is a synopsis of the Feb. 12-14, 1990 workshop on magnetic switching as it applies primarily to pulse compression (power transformation). During the course of the Workshop at Granlibakken, a great deal of information was amassed and a keen insight into both the problems and opportunities as to the use of this switching approach was developed. The segmented workshop format proved ideal for identifying key aspects affecting optimum performance in a variety of applications. Individual groups of experts addressed network and system modeling, magnetic materials, power conditioning, core cooling and dielectrics, and finally circuits and application. At the end, they came together to consolidate their input and formulate the workshop's conclusions, identifying roadblocks or suggesting research projects, particularly as they apply to magnetic switching's trump card - its high-average-power-handling capability (at least on a burst-mode basis). The workshop was especially productive both in the quality and quantity of information transfer in an environment conducive to a free and open exchange of ideas. We will not delve into the organization proper of this meeting, rather we wish to commend to the interested reader this volume, which provides the definitive and most up-to-date compilation on the subject of magnetic pulse compression from underlying principles to current state of the art as well as the prognosis for the future of magnetic pulse compression as a consensus of the workshop's organizers and participants.

  10. Compressible magnetohydrodynamic sawtooth crash

    NASA Astrophysics Data System (ADS)

    Sugiyama, Linda E.

    2014-02-01

    In a toroidal magnetically confined plasma at low resistivity, compressible magnetohydrodynamic (MHD) predicts that an m = 1/n = 1 sawtooth has a fast, explosive crash phase with abrupt onset, rate nearly independent of resistivity, and localized temperature redistribution similar to experimental observations. Large scale numerical simulations show that the 1/1 MHD internal kink grows exponentially at a resistive rate until a critical amplitude, when the plasma motion accelerates rapidly, culminating in fast loss of the temperature and magnetic structure inside q < 1, with somewhat slower density redistribution. Nonlinearly, for small effective growth rate the perpendicular momentum rate of change remains small compared to its individual terms ∇p and J × B until the fast crash, so that the compressible growth rate is determined by higher order terms in a large aspect ratio expansion, as in the linear eigenmode. Reduced MHD fails completely to describe the toroidal mode; no Sweet-Parker-like reconnection layer develops. Important differences result from toroidal mode coupling effects. A set of large aspect ratio compressible MHD equations shows that the large aspect ratio expansion also breaks down in typical tokamaks with rq =1/Ro≃1/10 and a /Ro≃1/3. In the large aspect ratio limit, failure extends down to much smaller inverse aspect ratio, at growth rate scalings γ =O(ɛ2). Higher order aspect ratio terms, including B˜ϕ, become important. Nonlinearly, higher toroidal harmonics develop faster and to a greater degree than for large aspect ratio and help to accelerate the fast crash. The perpendicular momentum property applies to other transverse MHD instabilities, including m ≥ 2 magnetic islands and the plasma edge.

  11. Fast Compressive Tracking.

    PubMed

    Zhang, Kaihua; Zhang, Lei; Yang, Ming-Hsuan

    2014-10-01

    It is a challenging task to develop effective and efficient appearance models for robust object tracking due to factors such as pose variation, illumination change, occlusion, and motion blur. Existing online tracking algorithms often update models with samples from observations in recent frames. Despite much success has been demonstrated, numerous issues remain to be addressed. First, while these adaptive appearance models are data-dependent, there does not exist sufficient amount of data for online algorithms to learn at the outset. Second, online tracking algorithms often encounter the drift problems. As a result of self-taught learning, misaligned samples are likely to be added and degrade the appearance models. In this paper, we propose a simple yet effective and efficient tracking algorithm with an appearance model based on features extracted from a multiscale image feature space with data-independent basis. The proposed appearance model employs non-adaptive random projections that preserve the structure of the image feature space of objects. A very sparse measurement matrix is constructed to efficiently extract the features for the appearance model. We compress sample images of the foreground target and the background using the same sparse measurement matrix. The tracking task is formulated as a binary classification via a naive Bayes classifier with online update in the compressed domain. A coarse-to-fine search strategy is adopted to further reduce the computational complexity in the detection procedure. The proposed compressive tracking algorithm runs in real-time and performs favorably against state-of-the-art methods on challenging sequences in terms of efficiency, accuracy and robustness. PMID:26352631

  12. Comparative data compression techniques and multi-compression results

    NASA Astrophysics Data System (ADS)

    Hasan, M. R.; Ibrahimy, M. I.; Motakabber, S. M. A.; Ferdaus, M. M.; Khan, M. N. H.

    2013-12-01

    Data compression is very necessary in business data processing, because of the cost savings that it offers and the large volume of data manipulated in many business applications. It is a method or system for transmitting a digital image (i.e., an array of pixels) from a digital data source to a digital data receiver. More the size of the data be smaller, it provides better transmission speed and saves time. In this communication, we always want to transmit data efficiently and noise freely. This paper will provide some compression techniques for lossless text type data compression and comparative result of multiple and single compression, that will help to find out better compression output and to develop compression algorithms.

  13. Compression and Entrapment Syndromes

    PubMed Central

    Heffernan, L.P.; Benstead, T.J.

    1987-01-01

    Family physicians are often confronted by patients who present with pain, numbness and weakness. Such complaints, when confined to a single extremity, most particularly to a restricted portion of the extremity, may indicate focal dysfunction of peripheral nerve structures arising from compression and/or entrapment, to which such nerves are selectively vulnerable. The authors of this article consider the paramount clinical features that allow the clinician to arrive at a correct diagnosis, reviews major points in differential diagnosis, and suggest appropriate management strategies. PMID:21263858

  14. Avalanches in Wood Compression.

    PubMed

    Mäkinen, T; Miksic, A; Ovaska, M; Alava, Mikko J

    2015-07-31

    Wood is a multiscale material exhibiting a complex viscoplastic response. We study avalanches in small wood samples in compression. "Woodquakes" measured by acoustic emission are surprisingly similar to earthquakes and crackling noise in rocks and laboratory tests on brittle materials. Both the distributions of event energies and of waiting (silent) times follow power laws. The stress-strain response exhibits clear signatures of localization of deformation to "weak spots" or softwood layers, as identified using digital image correlation. Even though material structure-dependent localization takes place, the avalanche behavior remains scale-free. PMID:26274428

  15. Compression test apparatus

    NASA Technical Reports Server (NTRS)

    Shanks, G. C. (Inventor)

    1981-01-01

    An apparatus for compressive testing of a test specimen may comprise vertically spaced upper and lower platen members between which a test specimen may be placed. The platen members are supported by a fixed support assembly. A load indicator is interposed between the upper platen member and the support assembly for supporting the total weight of the upper platen member and any additional weight which may be placed on it. Operating means are provided for moving the lower platen member upwardly toward the upper platen member whereby an increasing portion of the total weight is transferred from the load indicator to the test specimen.

  16. Sampling video compression system

    NASA Technical Reports Server (NTRS)

    Matsumoto, Y.; Lum, H. (Inventor)

    1977-01-01

    A system for transmitting video signal of compressed bandwidth is described. The transmitting station is provided with circuitry for dividing a picture to be transmitted into a plurality of blocks containing a checkerboard pattern of picture elements. Video signals along corresponding diagonal rows of picture elements in the respective blocks are regularly sampled. A transmitter responsive to the output of the sampling circuitry is included for transmitting the sampled video signals of one frame at a reduced bandwidth over a communication channel. The receiving station is provided with a frame memory for temporarily storing transmitted video signals of one frame at the original high bandwidth frequency.

  17. Ultrasound beamforming using compressed data.

    PubMed

    Li, Yen-Feng; Li, Pai-Chi

    2012-05-01

    The rapid advancements in electronics technologies have made software-based beamformers for ultrasound array imaging feasible, thus facilitating the rapid development of high-performance and potentially low-cost systems. However, one challenge to realizing a fully software-based system is transferring data from the analog front end to the software back end at rates of up to a few gigabits per second. This study investigated the use of data compression to reduce the data transfer requirements and optimize the associated trade-off with beamforming quality. JPEG and JPEG2000 compression techniques were adopted. The acoustic data of a line phantom were acquired with a 128-channel array transducer at a center frequency of 3.5 MHz, and the acoustic data of a cyst phantom were acquired with a 64-channel array transducer at a center frequency of 3.33 MHz. The receive-channel data associated with each transmit event are separated into 8 × 8 blocks and several tiles before JPEG and JPEG2000 data compression is applied, respectively. In one scheme, the compression was applied to raw RF data, while in another only the amplitude of baseband data was compressed. The maximum compression ratio of RF data compression to produce an average error of lower than 5 dB was 15 with JPEG compression and 20 with JPEG2000 compression. The image quality is higher with baseband amplitude data compression than with RF data compression; although the maximum overall compression ratio (compared with the original RF data size), which was limited by the data size of uncompressed phase data, was lower than 12, the average error in this case was lower than 1 dB when the compression ratio was lower than 8. PMID:22434817

  18. Band gap engineering of MoS2 upon compression

    NASA Astrophysics Data System (ADS)

    López-Suárez, Miquel; Neri, Igor; Rurali, Riccardo

    2016-04-01

    Molybdenum disulfide (MoS2) is a promising candidate for 2D nanoelectronic devices, which shows a direct band-gap for monolayer structure. In this work we study the electronic structure of MoS2 upon both compressive and tensile strains with first-principles density-functional calculations for different number of layers. The results show that the band-gap can be engineered for experimentally attainable strains (i.e., ±0.15). However, compressive strain can result in bucking that can prevent the use of large compressive strain. We then studied the stability of the compression, calculating the critical strain that results in the on-set of buckling for free-standing nanoribbons of different lengths. The results demonstrate that short structures, or few-layer MoS2, show semi-conductor to metal transition upon compressive strain without bucking.

  19. Compression of Martian atmosphere for production of oxygen

    NASA Technical Reports Server (NTRS)

    Lynch, D. C.; Cutler, A. H.; Nolan, P. E.

    1991-01-01

    The compression of CO2 from the Martian atmosphere for production of O2 via an electrochemical cell is addressed. Design specifications call for an oxygen production rate of 10 kg per day and for compression of 50 times that mass of CO2. Those specifications require a compression rate of over 770 cfm at standard Martian temperature and pressure (SMTP). Much of the CO2 being compressed represents waste, unless it can be recycled. Recycling can reduce the volume of gas that must be compressed to 40 cfm at SMTP. That volume reduction represents significant mass savings in the compressor, heating equipment, filters, and energy source. Successful recycle of the gas requires separation of CO (produced in the electrochemical cell) from CO2, N2, and Ar found in the Martian atmosphere. That aspect was the focus of this work.

  20. Digital mammography, cancer screening: Factors important for image compression

    NASA Technical Reports Server (NTRS)

    Clarke, Laurence P.; Blaine, G. James; Doi, Kunio; Yaffe, Martin J.; Shtern, Faina; Brown, G. Stephen; Winfield, Daniel L.; Kallergi, Maria

    1993-01-01

    The use of digital mammography for breast cancer screening poses several novel problems such as development of digital sensors, computer assisted diagnosis (CAD) methods for image noise suppression, enhancement, and pattern recognition, compression algorithms for image storage, transmission, and remote diagnosis. X-ray digital mammography using novel direct digital detection schemes or film digitizers results in large data sets and, therefore, image compression methods will play a significant role in the image processing and analysis by CAD techniques. In view of the extensive compression required, the relative merit of 'virtually lossless' versus lossy methods should be determined. A brief overview is presented here of the developments of digital sensors, CAD, and compression methods currently proposed and tested for mammography. The objective of the NCI/NASA Working Group on Digital Mammography is to stimulate the interest of the image processing and compression scientific community for this medical application and identify possible dual use technologies within the NASA centers.

  1. Restricted isometry properties and nonconvex compressive sensing

    NASA Astrophysics Data System (ADS)

    Chartrand, Rick; Staneva, Valentina

    2008-06-01

    The recently emerged field known as compressive sensing has produced powerful results showing the ability to recover sparse signals from surprisingly few linear measurements, using ell1 minimization. In previous work, numerical experiments showed that ellp minimization with 0 < p < 1 recovers sparse signals from fewer linear measurements than does ell1 minimization. It was also shown that a weaker restricted isometry property is sufficient to guarantee perfect recovery in the ellp case. In this work, we generalize this result to an ellp variant of the restricted isometry property, and then determine how many random, Gaussian measurements are sufficient for the condition to hold with high probability. The resulting sufficient condition is met by fewer measurements for smaller p. This adds to the theoretical justification for the methods already being applied to replacing high-dose CT scans with a small number of x-rays and reducing MRI scanning time. The potential benefits extend to any application of compressive sensing.

  2. Turbulence modeling for high speed compressible flows

    NASA Technical Reports Server (NTRS)

    Chandra, Suresh

    1993-01-01

    The following grant objectives were delineated in the proposal to NASA: to offer course work in computational fluid dynamics (CFD) and related areas to enable mechanical engineering students at North Carolina A&T State University (N.C. A&TSU) to pursue M.S. studies in CFD, and to enable students and faculty to engage in research in high speed compressible flows. Since no CFD-related activity existed at N.C. A&TSU before the start of the NASA grant period, training of students in the CFD area and initiation of research in high speed compressible flows were proposed as the key aspects of the project. To that end, graduate level courses in CFD, boundary layer theory, and fluid dynamics were offered. This effort included initiating a CFD course for graduate students. Also, research work was performed on studying compressibility effects in high speed flows. Specifically, a modified compressible dissipation model, which included a fourth order turbulent Mach number term, was incorporated into the SPARK code and verified for the air-air mixing layer case. The results obtained for this case were compared with a wide variety of experimental data to discern the trends in the mixing layer growth rates with varying convective Mach numbers. Comparison of the predictions of the study with the results of several analytical models was also carried out. The details of the research study are described in the publication entitled 'Compressibility Effects in Modeling Turbulent High Speed Mixing Layers,' which is attached to this report.

  3. Turbulence modeling for high speed compressible flows

    NASA Astrophysics Data System (ADS)

    Chandra, Suresh

    1993-08-01

    The following grant objectives were delineated in the proposal to NASA: to offer course work in computational fluid dynamics (CFD) and related areas to enable mechanical engineering students at North Carolina A&T State University (N.C. A&TSU) to pursue M.S. studies in CFD, and to enable students and faculty to engage in research in high speed compressible flows. Since no CFD-related activity existed at N.C. A&TSU before the start of the NASA grant period, training of students in the CFD area and initiation of research in high speed compressible flows were proposed as the key aspects of the project. To that end, graduate level courses in CFD, boundary layer theory, and fluid dynamics were offered. This effort included initiating a CFD course for graduate students. Also, research work was performed on studying compressibility effects in high speed flows. Specifically, a modified compressible dissipation model, which included a fourth order turbulent Mach number term, was incorporated into the SPARK code and verified for the air-air mixing layer case. The results obtained for this case were compared with a wide variety of experimental data to discern the trends in the mixing layer growth rates with varying convective Mach numbers. Comparison of the predictions of the study with the results of several analytical models was also carried out. The details of the research study are described in the publication entitled 'Compressibility Effects in Modeling Turbulent High Speed Mixing Layers,' which is attached to this report.

  4. GPA/GPSA/OSU-Okmulgee natural gas compression technician training program

    SciTech Connect

    Doede, S.

    1999-07-01

    Approximately one year ago, OSU-Okmulgee and the Gas Processors Association began discussions about the possibility of developing a natural Gas Technician Training Program for GPA members. Following a presentation to the Membership and Services Committee, Chairman John Ehlers solicited and obtained the approval of the GPA Executive Committee to sponsor the program. Participation in the program was also made available to GPSA members. The purpose of the program is to upgrade the technical competency and professional level of incoming natural gas compression technicians. It educates students to analytically diagnose, service and maintain gas compression equipment and systems using industry recommended procedures, special tools and service information. It also provides course content, which will enable successful graduates to advance in position after additional experience, and to understand new systems, technologies and components as they are introduced. The two-year Associate-In-Applied Science Degree program includes six successive college semesters. Nearly one-half of the time is designated for technical/academic education at Oklahoma State University-Okmulgee with the balance of time allocated for on-the-job internship experiences at sponsoring GPA/GPSA members. Each block of technical education and general education course work is followed by an immediate work experience time period designated to reinforce the technical and general education. These time periods are approximately seven and one-half weeks in length each. It is essential for the success of the students and the program that the students' education at OSU-Okmulgee and work experiences at GPA/GPSA member facilities be closely aligned for maximum student learning and retention. In addition to technical classes on gas compression equipment and components, the courses offered in math, speech, technical writing, psychology and ethics for example, prepare students to be able to communicate well, get along

  5. COMPRESSION SEAL AND SEALING MATERIAL THEREFOR

    DOEpatents

    Branin, T.G.

    1962-05-29

    This patent relates to compression seal and more particularly to a seaiing material therefor. The sealing surface is a coating consisting of alternate layers of gold and of a non-gold metal having similar plastic flow properties under pressure as gold. The coating is substantially free from oxidation effects when exposed to ambient atmosphere and does not become brittle when worked, as in a valve. (AEC)

  6. Selfsimilar spherical compression waves in gas dynamics

    NASA Astrophysics Data System (ADS)

    Meyer-Ter-Vehn, J.; Schalk, C.

    1982-05-01

    A synopsis of different selfsimilar spherical compression waves is given pointing out their fundamental importance for the gas dynamics of inertial confinement fusion. Strong blast waves, various forms of isentropic collapsing hollow spheres are included. A classification is given in terms of six singular points which characterize the different solutions and the relations between them. The presentation closely follows Guderley's original work on imploding shock waves.

  7. Compressive Sensing DNA Microarrays

    PubMed Central

    2009-01-01

    Compressive sensing microarrays (CSMs) are DNA-based sensors that operate using group testing and compressive sensing (CS) principles. In contrast to conventional DNA microarrays, in which each genetic sensor is designed to respond to a single target, in a CSM, each sensor responds to a set of targets. We study the problem of designing CSMs that simultaneously account for both the constraints from CS theory and the biochemistry of probe-target DNA hybridization. An appropriate cross-hybridization model is proposed for CSMs, and several methods are developed for probe design and CS signal recovery based on the new model. Lab experiments suggest that in order to achieve accurate hybridization profiling, consensus probe sequences are required to have sequence homology of at least 80% with all targets to be detected. Furthermore, out-of-equilibrium datasets are usually as accurate as those obtained from equilibrium conditions. Consequently, one can use CSMs in applications in which only short hybridization times are allowed. PMID:19158952

  8. Perceptually Lossless Wavelet Compression

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B.; Yang, Gloria Y.; Solomon, Joshua A.; Villasenor, John

    1996-01-01

    The Discrete Wavelet Transform (DWT) decomposes an image into bands that vary in spatial frequency and orientation. It is widely used for image compression. Measures of the visibility of DWT quantization errors are required to achieve optimal compression. Uniform quantization of a single band of coefficients results in an artifact that is the sum of a lattice of random amplitude basis functions of the corresponding DWT synthesis filter, which we call DWT uniform quantization noise. We measured visual detection thresholds for samples of DWT uniform quantization noise in Y, Cb, and Cr color channels. The spatial frequency of a wavelet is r 2(exp -1), where r is display visual resolution in pixels/degree, and L is the wavelet level. Amplitude thresholds increase rapidly with spatial frequency. Thresholds also increase from Y to Cr to Cb, and with orientation from low-pass to horizontal/vertical to diagonal. We propose a mathematical model for DWT noise detection thresholds that is a function of level, orientation, and display visual resolution. This allows calculation of a 'perceptually lossless' quantization matrix for which all errors are in theory below the visual threshold. The model may also be used as the basis for adaptive quantization schemes.

  9. Cancer suppression by compression.

    PubMed

    Frieden, B Roy; Gatenby, Robert A

    2015-01-01

    Recent experiments indicate that uniformly compressing a cancer mass at its surface tends to transform many of its cells from proliferative to functional forms. Cancer cells suffer from the Warburg effect, resulting from depleted levels of cell membrane potentials. We show that the compression results in added free energy and that some of the added energy contributes distortional pressure to the cells. This excites the piezoelectric effect on the cell membranes, in particular raising the potentials on the membranes of cancer cells from their depleted levels to near-normal levels. In a sample calculation, a gain of 150 mV in is so attained. This allows the Warburg effect to be reversed. The result is at least partially regained function and accompanying increased molecular order. The transformation remains even when the pressure is turned off, suggesting a change of phase; these possibilities are briefly discussed. It is found that if the pressure is, in particular, applied adiabatically the process obeys the second law of thermodynamics, further validating the theoretical model. PMID:25520262

  10. Compressive Bilateral Filtering.

    PubMed

    Sugimoto, Kenjiro; Kamata, Sei-Ichiro

    2015-11-01

    This paper presents an efficient constant-time bilateral filter that produces a near-optimal performance tradeoff between approximate accuracy and computational complexity without any complicated parameter adjustment, called a compressive bilateral filter (CBLF). The constant-time means that the computational complexity is independent of its filter window size. Although many existing constant-time bilateral filters have been proposed step-by-step to pursue a more efficient performance tradeoff, they have less focused on the optimal tradeoff for their own frameworks. It is important to discuss this question, because it can reveal whether or not a constant-time algorithm still has plenty room for improvements of performance tradeoff. This paper tackles the question from a viewpoint of compressibility and highlights the fact that state-of-the-art algorithms have not yet touched the optimal tradeoff. The CBLF achieves a near-optimal performance tradeoff by two key ideas: 1) an approximate Gaussian range kernel through Fourier analysis and 2) a period length optimization. Experiments demonstrate that the CBLF significantly outperforms state-of-the-art algorithms in terms of approximate accuracy, computational complexity, and usability. PMID:26068315