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1

A 4-Day Work Week That Works.  

ERIC Educational Resources Information Center

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,…

Walker, Kenneth; Timmerman, Linda

1980-01-01

2

Weekly Quizzing Really Works!: Online Software Makes It Easy  

ERIC Educational Resources Information Center

Frequent quizzing prods students to keep up with course work--and keeps them on their toes. The Internet offers a great tool for frequent quizzing. In this article, the author shares his experience quizzing his students weekly using his university's online learning system, WebCT, in the hope that this experience will prove useful to other…

Waite, Jerry

2007-01-01

3

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

PubMed

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

Caldicott, Catherine V; Holsapple, James W

2008-01-01

4

Birth of the Four-Day Work Week.  

ERIC Educational Resources Information Center

Indian Hills Community College, faced with rising utility bills dues to inadequate insulation in the campus's older buildings, now utilizes a four-day week during the winter quarter as an energy conservation measure. Planning for the implementation of the four-day week, which began in 1976, was coordinated by an overall energy committee made up of…

Hellyer, Lyle

5

39 Hours--Engineering the Birth of the Shorter Working Week?  

ERIC Educational Resources Information Center

The 1979 agreement in the engineering industry was a watershed in British industrial relations. It seems very likely that the significance of the 39-hour week is that it is the beginning of a series of reductions in the basic working week. The authors argue that 39 hours is an awkward figure in daily or weekly schedules. (SSH)

Bastin, Garry; Fahey, Walter

1982-01-01

6

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

ERIC Educational Resources Information Center

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…

Dundes, Lauren; Marx, Jeff

2007-01-01

7

Resolution of extensive leptomeningeal metastasis and clinical spinal cord compression from breast cancer using weekly docetaxel chemotherapy.  

PubMed

Metastatic breast cancer to the leptomeninges is a late event in the disease course and is associated with significant morbidity and a grave prognosis. Treatment typically involves direct intrathecal injection of chemotherapy into the cerebrospinal fluid compartment since systemic chemotherapy penetrates poorly to the central nervous system. Here we report an interesting clinical observation involving a patient presenting with leptomeningeal spread of breast cancer causing extensive spinal cord compression with obliteration of the subarachnoid space, thus precluding the use of direct intrathecal chemotherapy. We administered systemic chemotherapy using weekly docetaxel with complete radiographic resolution of her disease and recovery from clinical spinal cord compression. While this is a single clinical observation, weekly administration of docetaxel in this circumstance may have been associated with improved drug "escape" into the central nervous system and better antitumor effect. Because leptomeningeal disease is typically a late event in metastatic breast cancer, resistance to therapeutic intervention may reflect intrinsically resistant disease in the setting of extensive prior therapy rather than a routine problem with systemic drug delivery to the CNS. Studying patterns of disease relapse in patients who had received adjuvant weekly taxanes may provide insights into this hypothesis. PMID:22037782

Wilson, Bethany; Sapp, Christy; Abdeen, Ghadeer; Kamona, Atheel; Massarweh, Suleiman

2012-01-01

8

Target compressions by working fluids driven with solid liner implosions  

NASA Technical Reports Server (NTRS)

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.

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

9

Changes in lung function after working with the shotcrete lining method under compressed air conditions  

Microsoft Academic Search

Shotcrete techniques under compressed air are increasingly applied in the construction of tunnels. Up to now little is known about the influence of shotcrete dusts on the function of the lung. The lung function of 30 miners working with shotcrete under compressed air (before and after one shift) was measured. They carried personal air samplers to assess the total dust

R Kessel; M Redl; R Mauermayer; G J Praml

1989-01-01

10

Permanent stress may be the trigger of an acute myocardial infarction on the first work-day of the week.  

PubMed

Numerous studies have reported the weekly variation of an acute myocardial infarction. The Monday peek has been connected with higher rate of physical and mental, work-related stress. We wished to study the weekly variation of an acute myocardial infarction (AMI) in the group of workers and pensioners, and to find out whether National Holidays on the first day of the week could influence the weekly rhythm of an acute myocardial infarction. We carried out the retrospective analysis of patients admitted to Hungarian hospitals with the diagnose of an AMI (n=90,187) between 2002 and 2007. According to the morbidity data of an AMI, the weekly peek was detected on the first work-day of the week, showing a gradually decreasing tendency until the end of the week. Morbidity rates on Mondays being National Holidays were similar to the number of events on Saturdays and Sundays (Z=-24,431; p<0.001). There was a significant difference between the number of events on work-days and weekends (Z=-27,321; p<0.001). No marked difference was found between workers under the age of 65 and pensioners above the age of 65, or between the two sexes. The results of our study reveal that the occurrence of an AMI shows characteristic changes throughout the days of the week, and the first work-days of the week may be related to higher incidence of an acute myocardial infarction. PMID:19345426

Bodis, Jozsef; Boncz, Imre; Kriszbacher, Ildiko

2010-10-29

11

Working fluids selection for fishing boats waste heat powered organic Rankine-vapor compression ice maker  

NASA Astrophysics Data System (ADS)

To utilize waste heat from fishing boats, an organic Rankine cycle/vapor compression cycle system was employed for ice making and a thermodynamic model was developed. Six working fluids were selected and compared in order to identify suitable working fluids which may yield high system efficiencies. The calculated results show that R600a is most suitable working fluid through comprehensive comparison of efficiency, size parameter, pressure ratio, coefficient of performance, system pressure and safety.

Bu, Xianbiao; Wang, Lingbao; Li, Huashan

2014-04-01

12

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

PubMed

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

Mano, Y; Shibayama, M

1987-01-01

13

Simulation and experiment research on wide ranging working process of scroll expander driven by compressed air  

Microsoft Academic Search

Scroll expanders are widely used in the small energy recovery systems to recover mechanical energy from compressed air. A simulation model has been developed in this paper by taking the suction loss, leakage loss, heat transfer loss, and discharge loss into consideration. This simulation model is validated by comparison with the experimental results. The deviation of the actual working process

Liu Guangbin; Zhao Yuanyang; Li Liansheng; Shu Pengcheng

2010-01-01

14

29 CFR 1926.913 - Blasting in excavation work under compressed air.  

Code of Federal Regulations, 2010 CFR

...Explosives § 1926.913 Blasting in excavation work under compressed...directly from the magazines to the blasting zone and immediately loaded...excavation is in mixed face, blasting shall be performed with light...burden on each hole. Advance drilling shall be performed as...

2012-07-01

15

Effect of Reducing Interns' Weekly Work Hours on Sleep and Attentional Failures  

Microsoft Academic Search

background Knowledge of the physiological effects of extended (24 hours or more) work shifts in postgraduate medical training is limited. We aimed to quantify work hours, sleep, and attentional failures among first-year residents (postgraduate year 1) during a tradition- al rotation schedule that included extended work shifts and during an intervention schedule that limited scheduled work hours to 16 or

Steven W. Lockley; John W. Cronin; Erin E. Evans; Brian E. Cade; Clark J. Lee; Christopher P. Landrigan; Jeffrey M. Rothschild; Joel T. Katz; Craig M. Lilly; Peter H. Stone; Daniel Aeschbach; Charles A. Czeisler

2004-01-01

16

Capitol Hill Recognizes National School Psychology Week and the Work of School Psychologists  

ERIC Educational Resources Information Center

In honor of National School Psychology Week, the NASP Government and Professional Relations (GPR) and Communications committees and NASP staff joined forces on a campaign to help elected officials on Capitol Hill learn about the positive contributions of school psychologists and how their services impact student mental health and learning. This…

Communique, 2010

2010-01-01

17

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

ERIC Educational Resources Information Center

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…

Frase, Peter; Gornick, Janet C.

2013-01-01

18

Irreversible compressible work and available potential energy dissipation in turbulent stratified fluids  

NASA Astrophysics Data System (ADS)

Although it plays a key role in the theory of stratified turbulence, the concept of available potential energy (APE) dissipation has remained until now a rather mysterious quantity, owing to the lack of rigorous result about its irreversible character or energy conversion type. Here, we show by using rigorous energetics considerations rooted in the analysis of the Navier-Stokes for a fully compressible fluid with a nonlinear equation of state that the APE dissipation is an irreversible energy conversion that dissipates kinetic energy into internal energy, exactly as viscous dissipation. These results are established by showing that APE dissipation contributes to the irreversible production of entropy, and by showing that it is a part of the work of expansion/contraction. Our results provide a new interpretation of the entropy budget, that leads to a new exact definition of turbulent effective diffusivity, which generalizes the Osborn-Cox model, as well as a rigorous decomposition of the work of expansion/contraction into reversible and irreversible components. In the context of turbulent mixing associated with parallel shear flow instability, our results suggests that there is no irreversible transfer of horizontal momentum into vertical momentum, as seems to be required when compressible effects are neglected, with potential consequences for the parameterizations of momentum dissipation in the coarse-grained Navier-Stokes equations.

Tailleux, Rémi

2013-07-01

19

The 88-Hour Family: Effects of the 80-Hour Work Week on Marriage and Childbirth in a Surgical Residency  

PubMed Central

The restriction of the resident physician work week to 80 hours has had dramatic affects on resident education and life-style. While effects on mood, psychological distress, and burn-out have been studied, the resultant changes in tangible quality of life have received little attention. birth rate was considered a measurable, relevant outcome. The resident marital and parental status by duty month was collected from a single orthopaedic surgical residency program for the four academic years preceding and following the implementation of the 80-hour work week. the number of births to residents during these periods were also tallied. The relative prevalence of positive marital status changed very little between residents in the two time durations from 66 to 71 percent, but parental status increased from 27 to 43 percent. The number of births per married resident duty year also increased from 0.23 pre-restrictions to 0.32 post-restrictions. While the individual decisions involved in generating these observed changes are complex and difficult to entirely decipher, it is thought that an increased perception of life-control within the work-hour restrictions may have prompted the dramatic changes in birth rate among resident families.

Jones, Arden M; Jones, Kevin B

2007-01-01

20

Day of the week lost time occupational injury trends in the US by gender and industry and their implications for work scheduling  

Microsoft Academic Search

While there is a growing body of research on the impact of work schedules on the risk of occupational injuries, there has been little investigation into the impact that the day of the week might have. The present research was completed to explore day of the week trends, reasons for such trends and the corresponding implications for work scheduling. Data

G. E. Brogmus

2007-01-01

21

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

...overtime in excess of 12 daily or 56 weekly hours is worked in the workweek. 794.142...Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR STATEMENTS...overtime in excess of 12 daily or 56 weekly hours is worked in the workweek. (a)...

2009-07-01

22

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

...overtime in excess of 12 daily or 56 weekly hours is worked in the workweek. 794.142...Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR STATEMENTS...overtime in excess of 12 daily or 56 weekly hours is worked in the workweek. (a)...

2010-07-01

23

Work plan for upgrading the 241-A-701 compressed air system and motor control center. Revision 1  

Microsoft Academic Search

This work plan will outline the responsibilities associated with the 241-A-701 Compressed Air System (CAS) and Motor Control Center (MCC) upgrades. All activities required to design, install, test, and operate the modified systems are addressed in this document. Upgrades Technical Support (UTS) of TWRS Engineering is responsible for the completion of all tasks associated with this upgrade. UTS will coordinate

1995-01-01

24

Work of CPR During Two Different Compression to Ventilation Ratios With Real-time Feedback  

PubMed Central

Background The 2005 Emergency Cardiac Care guidelines for basic life support (BLS) recommend a compression to ventilation ratio of 30:2. The effect of the additional exertion required to deliver more chest compressions may present a considerable physical burden on the provider. Objective To compare cardiopulmonary resuscitation (CPR) performance and perceived exertion during compression to ventilation ratios of 15:2 and 30:2 with real-time feedback during two-rescuer CPR. Methods Eighteen BLS-certified healthcare providers each performed five minutes of chest compressions on a manikin with compression to ventilation ratios of 15:2 or 30:2 on two separate sessions. Heart rate, capillary lactate, and OMNI Rate of Perceived Exertion (RPE) were recorded before and after each session. Subjects were given continuous, automated, feedback via an accelerometer that measured rate, depth, duration, and release of compressions. Compression measurements and feedback messages were recorded continuously during each five minute session. Data were analyzed using descriptive statistics and t-test to compare groups. Repeated measures ANOVA was used to compare data over the five minute epoch. Results After performing external chest compressions for five minutes, peak heart rate (102±24 vs. 106±27), capillary lactate (2.2±0.95 vs. 2.2±0.96), and OMNI RPE (4.3±1.2 vs. 4.6±1.1) were higher were higher than baseline, but did not differ between 15:2 and 30:2. Compression rate (102 ± 24 vs.106 ± 27) and depth (38.8±3.6 vs. 38.2±2.9) did not differ between 15:2 and 30:2 groups or at any minute. Total chest compressions delivered were higher (p<0.05) in the 30:2 group (457±43) compared to 15:2 (379±28). The average no flow time was lower (p<0.05) in the 30:2 group (22±3.03) compared to the 15:2 group (33±2.64). Number of correction prompts (48±55 vs. 64±70) did not differ significantly between the 15:2 and 30:2 groups. Conclusions In a cohort of healthcare providers, increasing the CPR ratio from 15:2 to 30:2 did not change physical or perceived exertion during a five-minute bout of CPR when continuous, real-time feedback is provided. The 30:2 compression to ventilation ratio resulted in more chest compressions per minute without decreasing CPR quality.

Betz, Amy E.; Callaway, Clifton W.; Hostler, David; Rittenberger, Jon C.

2008-01-01

25

Work plan for upgrading the 241-A-701 compressed air system and motor control center. Revision 1  

SciTech Connect

This work plan will outline the responsibilities associated with the 241-A-701 Compressed Air System (CAS) and Motor Control Center (MCC) upgrades. All activities required to design, install, test, and operate the modified systems are addressed in this document. Upgrades Technical Support (UTS) of TWRS Engineering is responsible for the completion of all tasks associated with this upgrade. UTS will coordinate the upgrade activities, and ensure all tasks are successfully completed on or before the scheduled dates. The primary objective of the 241-A-701 Compressor and MCC Upgrade is to provide a reliable source of process and instrument compressed air to the A, AX, AY, and AZ tank farms.

Carpenter, K.E.

1995-01-17

26

Publishers Weekly  

NSDL National Science Digital Library

Are you interested in learning what forays university presses are making into the world of electronic publishing? Perhaps you'd like a selection of thoughtful weblogs on new literary works? The Publishers Weekly website has all of that covered, and a great deal more. Designed to complement their print publication, the site has a "Latest Stories" section front and center on their homepage. Checking this area out (and perhaps signing up for their RSS feed) is a good way to stay abreast of important developments in the world of publishing. Also on the homepage visitors will find four sections of primary interest: "Blogs", "Talkback", "Podcasts", and "Photos". The "Talkback" frequently features well-reasoned commentary from readers on recent stories and the "Blogs" area includes links to weblogs maintained by Publishers Weekly staff members. Further down the homepage, visitors can expect to find new book reviews and sections dedicated to children's literature, comics, and independent news.

27

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

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…

Robert Wood Johnson Foundation, 2013

2013-01-01

28

Census of Population: 1970. Weeks Worked, Class of Worker, Last Occupation of the Experienced Unemployed, and Labor Mobility for the United States: 1970.  

National Technical Information Service (NTIS)

The report provides data for persons in the United States in 1970 on the number of weeks worked in 1969, class of worker of the employed and last occupation of the experienced unemployed. Figures are also given for the labor mobility of selected groups be...

1972-01-01

29

Effects of 12-Week Bacopa monnieri Consumption on Attention, Cognitive Processing, Working Memory, and Functions of Both Cholinergic and Monoaminergic Systems in Healthy Elderly Volunteers  

PubMed Central

At present, the scientific evidence concerning the effect of Bacopa monnieri on brain activity together with working memory is less available. Therefore, we aimed to determine the effect of B. monnieri on attention, cognitive processing, working memory, and cholinergic and monoaminergic functions in healthy elderly. A randomized double-blind placebo-controlled design was utilized. Sixty healthy elderly subjects (mean age 62.62 years; SD 6.46), consisting of 23 males and 37 females, received either a standardized extract of B. monnieri (300 and 600?mg) or placebo once daily for 12 weeks. The cholinergic and monoaminergic systems functions were determined using AChE and MAO activities. Working memory was assessed using percent accuracy and reaction time of various memory tests as indices, whereas attention and cognitive processing were assessed using latencies and amplitude of N100 and P300 components of event-related potential. All assessments were performed before treatment, every four weeks throughout study period, and at four weeks after the cessation of intervention. B. monnieri-treated group showed improved working memory together with a decrease in both N100 and P300 latencies. The suppression of plasma AChE activity was also observed. These results suggest that B. monnieri can improve attention, cognitive processing, and working memory partly via the suppression of AChE activity.

Peth-Nui, Tatimah; Wattanathorn, Jintanaporn; Muchimapura, Supaporn; Tong-Un, Terdthai; Piyavhatkul, Nawanant; Rangseekajee, Poonsri; Ingkaninan, Kornkanok; Vittaya-areekul, Sakchai

2012-01-01

30

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

ERIC Educational Resources Information Center

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…

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

2009-01-01

31

Student understanding of the first law of thermodynamics: Relating work to the adiabatic compression of an ideal gas  

NSDL National Science Digital Library

We report on an investigation of student understanding of the first law of thermodynamics. The students involved were drawn from first-year university physics courses and a second-year thermal physics course. The emphasis was on the ability of the students to relate the first law to the adiabatic compression of an ideal gas. Although they had studied the first law, few students recognized its relevance. Fewer still were able to apply the concept of work to account for a change in temperature in an adiabatic process. Instead most of the students based their predictions and explanations on a misinterpretation of the ideal gas law. Even when ideas of energy and work were suggested, many students were unable to give a correct analysis. They frequently failed to differentiate the concepts of heat, temperature, work, and internal energy. Some of the difficulties that students had in applying the concept of work in a thermal process seemed to be related to difficulties with mechanics. Our findings also suggest that a misinterpretation of simple microscopic models may interfere with student ability to understand macroscopic phenomena. Implications for instruction in thermal physics and in mechanics are discussed.

Loverude, Michael E.; Kautz, Christian H.; Heron, Paula R.

2005-10-27

32

Experimental evaluation of a vapour compression plant performance using R134a, R407C and R22 as working fluids  

Microsoft Academic Search

In this paper, the influence of the main operating variables on the energetic characteristics of a vapour compression plant, based on experimental results, is addressed. The experimental tests are performed on a single-stage vapour compression plant using three different working fluids, R134a, R407C and R22. The operating variables considered are the evaporating pressure, the condensing pressure and the superheating degree

R Cabello; E Torrella; J Navarro-Esbr??

2004-01-01

33

Working Hours Flexibility. Background Paper No. 30.  

ERIC Educational Resources Information Center

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…

Staines, Graham L.

34

Age and Individual Differences in Prospective Memory during a "Virtual Week": The Roles of Working Memory, Vigilance, Task Regularity, and Cue Focality  

PubMed Central

Young (ages 18-22) and older (ages 61-87) adults (N=106) played the Virtual Week board game, which involves simulating common prospective memory (PM) tasks of everyday life (e.g., taking medication), and performed working memory (WM) and vigilance tasks. The Virtual Week game includes regular (repeated) and irregular (non-repeated) PM tasks with cues that are either more or less focal to other ongoing activities. Age differences in PM were reduced for repeated tasks and performance improved over the course of the week, suggesting retrieval was more spontaneous or habitual. Correlations with WM within each age group were reduced for PM tasks that had more regular or focal cues. WM (but not vigilance) ability was a strong predictor of irregular PM tasks with less focal cues. Taken together, these results support the hypothesis that habitual and focally-cued PM tasks are less demanding of attentional “resources” (specifically, WM), whereas tasks that are more demanding of controlled attentional processes produce larger age differences, which may be attributable to individual differences in WM.

Rose, Nathan S.; Rendell, Peter G.; McDaniel, Mark A.; Aberle, Ingo; Kliegel, Matthias

2011-01-01

35

Effects of four weeks of high-intensity interval training and creatine supplementation on critical power and anaerobic working capacity in college-aged men.  

PubMed

The critical power test provides 2 measures, critical power (CP) and anaerobic working capacity (AWC). In theory, the CP measurement represents the maximal power output that can be maintained without fatigue, and AWC is an estimate of work capacity associated with muscle energy reserves. High-intensity interval training (HIIT) has been shown to be an effective training method for improving endurance performance, including VO2PEAK. In addition, creatine (Cr) supplementation has been reported to improve AWC without training; however, it has shown no effect on CP. The purpose of this study was to examine the effects of 4 weeks of HIIT with Cr supplementation on CP and AWC. Forty-two recreationally active men volunteered to participate in this study. Participants were randomly assigned to 1 of 3 groups: Cr (n = 16), 10 g Cr + 10 g dextrose; placebo (PL, n = 16), 20 g dextrose; control (CON, n = 10), no treatment. Before and after supplementation, each participant performed a maximal oxygen consumption test VO2PEAK on a cycle ergometer to establish peak power output (PPO). Participants then completed a CP test involving 3 exercise bouts with the workloads set as a percentage of their PPO to determine CP and AWC. After a 2-week familiarization period of training and supplementing, PPO, CP, and AWC were remeasured before an additional 4 weeks of HIIT and supplementation were completed. Training consisted of 5 sets of 2-minute exercise bouts with 1 minute rest in between performed on the cycle ergometer, with intensities based on PPO. A significant improvement in CP was observed in the Cr group (6.72% +/- 2.54%), whereas PL showed no significant change (3.87% +/- 2.30%), and CON significantly decreased (6.27% +/- 2.38%). Furthermore, no changes in AWC were observed in any of the groups after treatment. The current findings suggest that Cr supplementation may enhance the effects of intense interval endurance training on endurance performance changes. PMID:19675499

Kendall, Kristina L; Smith, Abbie E; Graef, Jennifer L; Fukuda, David H; Moon, Jordan R; Beck, Travis W; Cramer, Joel T; Stout, Jeffrey R

2009-09-01

36

Baseball Weekly  

NSDL National Science Digital Library

USA Today has recently made its Baseball Weekly newspaper available via the Web. Included are stories on major league, minor league, and college baseball, as well as feature articles. Baseball Weekly also presents weekly fantasy league reports, which analyze player statistics in the context of fans who might have the players in a fantasy league -- a league in which "owners" compile teams of major league players and receive points based on those players' ongoing statistics. The fantasy league reports are one of the newspaper's best resources.

1998-01-01

37

Nickel Weeklies  

NSDL National Science Digital Library

A century or so, a nickel could buy a lot of entertainment. One such form of entertainment was the nickel weekly, which featured tales of detectives, Wild West characters, and evil villains. Bowling Green State University has created this thoroughly delightful digital collection of nickel weeklies for consumption by the general public. This collection includes 221 nickel weeklies, and visitors can browse these offerings by title, date, or author. Visitors can zoom in on the cover page of each weekly, or they may also download each title and view them at another more convenient moment. Users looking for a place to start might do well to look over "Adventures of Buffalo Bill from boyhood to manhood" by Colonel Prentiss Ingraham or "California Claude, the love bandit" by Captain Howard Holmes.

38

Solar Week  

NSDL National Science Digital Library

This site is intended to spark pre- and early teen girls' interest in pursuing careers in science through the study of recent solar physics discoveries. The set of daily activities is self-contained, so participation can be carried out on a day-to-day basis depending upon your schedule. One of the great strengths of this project is the interaction with real scientists who have first hand knowledge of the various topics which make up Solar Week. These activities will also be available after the period chosen for Solar Week, without real-time interaction with scientists. This website is designed as a week-long unit. Each day covers a different topic.

39

Effects of recovery sleep after one work week of mild sleep restriction on interleukin-6 and cortisol secretion and daytime sleepiness and performance.  

PubMed

One workweek of mild sleep restriction adversely impacts sleepiness, performance, and proinflammatory cytokines. Many individuals try to overcome these adverse effects by extending their sleep on weekends. To assess whether extended recovery sleep reverses the effects of mild sleep restriction on sleepiness/alertness, inflammation, and stress hormones, 30 healthy young men and women (mean age ± SD, 24.7 ± 3.5 yr; mean body mass index ± SD, 23.6 ± 2.4 kg/m(2)) participated in a sleep laboratory experiment of 13 nights [4 baseline nights (8 h/night), followed by 6 sleep restriction nights (6 h/night) and 3 recovery nights (10 h/night)]. Twenty-four-hour profiles of circulating IL-6 and cortisol, objective and subjective daytime sleepiness (Multiple Sleep Latency Test and Stanford Sleepiness Scale), and performance (Psychomotor Vigilance Task) were assessed on days 4 (baseline), 10 (after 1 wk of sleep restriction), and 13 (after 2 nights of recovery sleep). Serial 24-h IL-6 plasma levels increased significantly during sleep restriction and returned to baseline after recovery sleep. Serial 24-h cortisol levels during restriction did not change compared with baseline, but after recovery they were significantly lower. Subjective and objective sleepiness increased significantly after restriction and returned to baseline after recovery. In contrast, performance deteriorated significantly after restriction and did not improve after recovery. Extended recovery sleep over the weekend reverses the impact of one work week of mild sleep restriction on daytime sleepiness, fatigue, and IL-6 levels, reduces cortisol levels, but does not correct performance deficits. The long-term effects of a repeated sleep restriction/sleep recovery weekly cycle in humans remain unknown. PMID:23941878

Pejovic, Slobodanka; Basta, Maria; Vgontzas, Alexandros N; Kritikou, Ilia; Shaffer, Michele L; Tsaoussoglou, Marina; Stiffler, David; Stefanakis, Zacharias; Bixler, Edward O; Chrousos, George P

2013-10-01

40

Week 8  

NSDL National Science Digital Library

At week 8, the impact of an earthworm on decomposition is obvious and the material in the worm container is beginning to appear as compost. Keep in mind that the material within the worm-free container will decompose due to oxygen and bacteria, but at a much slower rate than the container with earthworms.

Katie Hale (CSUF;Biological Sciences)

2007-07-08

41

Washington Week  

NSDL National Science Digital Library

Beginning with its first program on February 23, 1967, Washington Week has provided intelligent and provocative roundtable discussion of major news events. Featured on PBS, the public affairs program has seen a number of hosts since its inception, and is currently under the direction of moderator Gwen Ifill, who has been in that position since 1999. The show is broadcast once a week, and addresses such timely topics as national security and the domestic economy. Visitors to the website can view each show in its entirety, and read transcripts of each program as well. Another nice feature of the site is âÂÂChat with GwenâÂÂ, which allows visitors to chat online with Ifill once a month. If visitors are looking for certain video clips, they can also search through the video archive to find commentaries by such distinguished columnists such as David Brooks and Thomas Friedman.

42

Student understanding of the first law of thermodynamics: Relating work to the adiabatic compression of an ideal gas  

Microsoft Academic Search

We report on an investigation of student understanding of the first law of thermodynamics. The students involved were drawn from first-year university physics courses and a second-year thermal physics course. The emphasis was on the ability of the students to relate the first law to the adiabatic compression of an ideal gas. Although they had studied the first law, few

Michael E. Loverude; Christian H. Kautz; Paula R. L. Heron

2002-01-01

43

Brain Week!  

NSDL National Science Digital Library

This week-long exploration of brain structure and function through hands-on experiments and web Treasure Hunts ends with an open inquiry on the brain designed by students. Exploration topics include brain parts and their functions, surface area, optic nerve activity, touch receptors, muscle spindle fibers, motor learning, neuroscientists, and the effects of drugs on the brain. This teaching resource was developed by a K-12 science teacher in the American Physiological SocietyÃÂs 2004 Frontiers in Physiology Program. For more information on this program, please visit www.frontiersinphys.org.

Ms. Rachel Gillis (Arsenal Technical High School)

2005-05-01

44

Project Week at Yeovil.  

ERIC Educational Resources Information Center

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)

Gadd, K. F.

1979-01-01

45

Collaborative work on evaluation of ovarian toxicity. 12) Effects of 2- or 4-week repeated dose studies and fertility study of indomethacin in female rats.  

PubMed

2-week and 4-week general toxicity studies of indomethacin, a nonselective inhibitor of cyclooxygenase 1 and 2, were performed using rats. A female fertility study was also conducted to compare the results to those of ovarian histopathological findings. The main purposes of the present studies are to assess whether a precise histopathological examination, taking the morphological changes the female reproductive organs undergo during each estrus phases into account, can evaluate toxicity to the ovaries, and to determine the optimal administration period for detecting ovarian toxicity. Indomethacin was administered on a daily basis to female Sprague-Dawley rats at doses of 0, 0.4, 1.3, or 4 mg/kg in the both the general toxicity studies and the female fertility study. In the general toxicity studies, unruptured follicles or luteinized cysts were observed histopathologically in the 4 mg/kg group in both the 2-week and 4-week studies. In addition, follicular cysts were found in the 4 mg/kg group in the 4-week study. Estrous cyclicity was not disturbed in both studies. There were no histopathological changes in the ovaries of the 1.3 mg/kg group in general toxicity studies. In the female fertility study, no toxic effects on female fertility parameters were detected in the 0.4 and 1.3 mg/kg group treated with indomethacin, but 8 of 10 rats in the 4 mg/kg group died or were sacrificed before completion of the dosing period. These results demonstrated that 2 weeks of indomethacin treatment is sufficient to detect unruptured follicles or luteinized cyst in the ovary. In addition, 4 weeks of dosing maybe required for induction of follicular cysts, although we could not clearly show that these histopathological changes would affect female fertility functions. These present studies suggest that a precise histopathological examination may be able to predict the effect of test articles on female reproductive functions. PMID:19265279

Tsubota, Kenjiro; Kushima, Kiyoshi; Yamauchi, Kenji; Matsuo, Seiki; Saegusa, Tadashi; Ito, Shin; Fujiwara, Michio; Matsumoto, Masahiro; Nakatsuji, Shunji; Seki, Jiro; Oishi, Yuji

2009-01-01

46

Clustering by compression  

Microsoft Academic Search

We present a new method for clustering based on compression. The method does not use subject-specific features or background knowl- edge, and works as follows: First, we determine a parameter-free, universal, similarity distance, the normalized compression distance or NCD, com- puted from the lengths of compressed data files (singly and in pairwise con- catenation). Second, we apply a hierarchical clustering

Rudi Cilibrasi; Paul M. B. Vitányi; Xin Li; Bin Ma

2003-01-01

47

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

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.

Orr, William; Vargas-Romero, Jose Antonio; Remes-Troche, Jose Maria; Morales-Arambula, Miguel; Soto-Perez, Julio Cesar; Mateos-Perez, Gualberto; Sobrino-Cossio, Sergio; Teramoto-Matsubara, Oscar; Lopez-Colombo, Aurelio; Orozco-Gamiz, Antonio; Saez-Rios, Adolfo; Arellano-Plancarte, Araceli; Chiu-Ugalde, Jazmin; Tholen, Anne; Horbach, Silke; Lundberg, Lars; Fass, Ronnie

2014-01-01

48

Data Compression.  

ERIC Educational Resources Information Center

Introduces this issue, which contains papers from the 1991 Data Compression Conference, and defines data compression. The two primary functions of data compression are described, i.e., storage and communications; types of data using compression technology are discussed; compression methods are explained; and current areas of research are…

Bookstein, Abraham; Storer, James A.

1992-01-01

49

Speech Compression and Synthesis.  

National Technical Information Service (NTIS)

This document reports on work towards a very low rate phonetic vocoder, text to speech, and multirate speech compression. This work included improvement of the phonetic synthesis algorithms and continued gathering of the diphone templates data base for ph...

M. Berouti J. Klovstad J. Makhoul R. Schwartz J. Sorensen

1979-01-01

50

Work  

NSDL National Science Digital Library

These web pages introduce the concept of work and its relation to energy. An example of electric work and energy using the example of a Van de Graaff Generator. These pages are part of "From Stargazers to Starships", an extensive web site that introduces topics in physics and astronomy using space exploration and space science. Translations are available in French and Spanish.

Stern, David

2006-07-16

51

Work-Related Injury Deaths Among Hispanics - United States, 1992-2006. Morbidity and Mortality Weekly Report, Volume 57, No. 22, June 6, 2008.  

National Technical Information Service (NTIS)

Hispanics are among the fastest-growing segments of the U.S. workforce (1). In 2006, an estimated 19.6 million workers in the United States were Hispanic, 56% of whom were foreign born* (2). To characterize work-related injury deaths among Hispanic worker...

2008-01-01

52

National Engineers Week  

NSDL National Science Digital Library

Now an annual event, National Engineers Week was founded by the National Society of Professional Engineers in 1951. In 1988, the National Engineers Week consortium expanded and now includes "more than 100 engineering, scientific, and education societies and major corporations dedicated to enhancing the public understanding of the engineering profession and to promoting pre-college interest in math, science, and engineering as a career option." From this website, visitors can read suggestions for ways to get involved in National Engineers Week (National Engineers Week 2004 was held February 22-28) and learn about other competitions for young and upcoming engineers. Also available online is the first Connecting the World teleconference which featured Alan Boeckmann, Chairman and CEO of Fluor Corporation, speaking about Engineering in the 21st Century. The website currently promotes the "Introduce a Girl to Engineering Day," which was presented to the United Nations as part of an international briefing, Girls and Technology: New Educational Opportunities. Another feature of interest is the section highlighting the accomplishments of engineers and their inspirational stories about becoming "the engineer behind the sounds of Star Wars," for example. The New Faces of Engineering program highlights the work of young engineers. A discussion forum and various educational resources are also available from this website. Finally, a section on Engineer / Volunteer Kits suggests ways engineers, community members and teachers can get involved in supporting up-and-coming engineers.

2005-11-06

53

National Engineers Week  

NSDL National Science Digital Library

Now an annual event, National Engineers Week was founded by the National Society of Professional Engineers in 1951. In 1988, the National Engineers Week consortium expanded and now includes "more than 100 engineering, scientific, and education societies and major corporations dedicated to enhancing the public understanding of the engineering profession and to promoting pre-college interest in math, science, and engineering as a career option." From this website, visitors can read suggestions for ways to get involved in National Engineers Week (National Engineers Week 2004 was held February 22-28) and learn about other competitions for young and upcoming engineers. Also available online is the first Connecting the World teleconference which featured Alan Boeckmann, Chairman and CEO of Fluor Corporation, speaking about Engineering in the 21st Century. The website currently promotes the "Introduce a Girl to Engineering Day," which was presented to the United Nations as part of an international briefing, Girls and Technology: New Educational Opportunities. Another feature of interest is the section highlighting the accomplishments of engineers and their inspirational stories about becoming "the engineer behind the sounds of Star Wars," for example. The New Faces of Engineering program highlights the work of young engineers. A discussion forum and various educational resources are also available from this website. Finally, a section on Engineer / Volunteer Kits suggests ways engineers, community members and teachers can get involved in supporting up-and-coming engineers.

54

Working  

NSDL National Science Digital Library

A new special section in the New York Times, Working, features articles on the American worker. For example, the current issue contains stories on the contrast between the recent trend in layoffs and employers's complaints that they are unable to fill job openings; what is "retaining and motivating...the American worker"; and the shortage of qualified legal talent. The site also offers a great deal of career and job advice such as an article on non-traditional jobs, job forecasts, and office design. Interviews include an audio piece with Robert B. Reich, the former US Secretary of Labor. And of course, what would a newspaper section on work be without a link to the Dilbert comic strip?

55

Video compression makes big gains  

Microsoft Academic Search

How new standards for video compression and new IC chips will change the worlds of computing, broadcasting, and communication is discussed. An explanation of how video compression works is given. The three digital video standards that have been proposed are described. They are the Joint Photographic Experts Group (JPEG) standard for still picture compression, the Consultative Committee on International Telephony

P. H. Ang; P. A. Ruetz; D. Auld

1991-01-01

56

Functional outcome after experimental cauda equina compression  

Microsoft Academic Search

Spinal nerve roots often sustain compression injuries. We used a Wistar rat model of the cauda equina syndrome to investigate such injuries. Rapid transient compression of the cauda equina was produced using a balloon catheter. The results were assessed by daily neurological examination and somatosensory evoked potential (SEP) recording before surgery and ten weeks after decompression. Compression of the spinal

Fares E. Sayegh; George A. Kapetanos; Pan P. Symeonides; George Anogiannakis; Minas Madentzidis

1997-01-01

57

Compression embedding  

DOEpatents

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%.

Sandford, II, Maxwell T. (Los Alamos, NM); Handel, Theodore G. (Los Alamos, NM); Bradley, Jonathan N. (Los Alamos, NM)

1998-01-01

58

Compression embedding  

DOEpatents

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.

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

1998-07-07

59

Compression embedding  

DOEpatents

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.

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

1998-03-10

60

Compression embedding  

DOEpatents

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.

Sandford, II, Maxwell T. (Los Alamos, NM); Handel, Theodore G. (Los Alamos, NM); Bradley, Jonathan N. (Los Alamos, NM)

1998-01-01

61

Modeling Compressed Turbulence  

SciTech Connect

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.

Israel, Daniel M. [Los Alamos National Laboratory

2012-07-13

62

Compressive Holography  

NASA Astrophysics Data System (ADS)

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 information with a small fill factor because object scattered fields are locally redundant. Incoherent image estimation is adopted for the expanded modulation transfer function and compressive reconstruction.

Lim, Se Hoon

63

Banned Books Week  

NSDL National Science Digital Library

Next week is Banned Books Week, and the American Library Association (ALA) offers this site giving background on Banned Books Week and censorship as well as resources to help teachers, librarians, and booksellers observe the week. Once again, the Harry Potter series tops this year's list of most challenged books. At the ALA site, users will find the complete list as well as the most challenged books of the past decade. In addition, the site hosts a press kit, resources for sale to celebrate the week, links to other banned books sites, and a page on book burning.

2000-01-01

64

Review of Recent Progress in Laser Plasma Interaction and Laser Compression Work at the Science Research Council Rutherford Laboratory Central Laser Facility.  

National Technical Information Service (NTIS)

The SRC two beam Nd glass laser facility with output of up to 40J per beam in 100 ps pulses and 80J per beam in 1.6 ns pulses has been used to study interactions in the critical density region, energy transport in solid targets and compression of spherica...

M. H. Key F. Gibson R. G. Evans

1979-01-01

65

Experimental evaluation of the internal heat exchanger influence on a vapour compression plant energy efficiency working with R22, R134a and R407C  

Microsoft Academic Search

Internal or liquid-suction heat exchangers are used in many refrigeration and air conditioning systems based on the vapour compression cycle, with the basic objective of assuring the entrance of refrigerant in liquid phase to the expansion device. This purpose is achieved by exchanging energy between the cool gaseous refrigerant leaving the evaporator and warm liquid refrigerant exiting the condenser. These

J. Navarro-Esbrí; R. Cabello; E. Torrella

2005-01-01

66

Space-time compressive imaging.  

PubMed

Compressive imaging systems typically exploit the spatial correlation of the scene to facilitate a lower dimensional measurement relative to a conventional imaging system. In natural time-varying scenes there is a high degree of temporal correlation that may also be exploited to further reduce the number of measurements. In this work we analyze space-time compressive imaging using Karhunen-Loève (KL) projections for the read-noise-limited measurement case. Based on a comprehensive simulation study, we show that a KL-based space-time compressive imager offers higher compression relative to space-only compressive imaging. For a relative noise strength of 10% and reconstruction error of 10%, we find that space-time compressive imaging with 8×8×16 spatiotemporal blocks yields about 292× compression compared to a conventional imager, while space-only compressive imaging provides only 32× compression. Additionally, under high read-noise conditions, a space-time compressive imaging system yields lower reconstruction error than a conventional imaging system due to the multiplexing advantage. We also discuss three electro-optic space-time compressive imaging architecture classes, including charge-domain processing by a smart focal plane array (FPA). Space-time compressive imaging using a smart FPA provides an alternative method to capture the nonredundant portions of time-varying scenes. PMID:22307131

Treeaporn, Vicha; Ashok, Amit; Neifeld, Mark A

2012-02-01

67

Problem of the Week Blog  

NSDL National Science Digital Library

This blog posts a weekly free problem scenario from The Math Forum inspired by current PoWs, student work, or daily encounters. The bloggers goal is to have the public read the posts and use the Notice-Wonder strategy to identify the mathematics in the post. The blog also contains reader comments and feedback.

Forum, Annie F.; Forum, Max R.

2013-01-01

68

Absolute compression test  

Microsoft Academic Search

This patent describes a method for measuring the absolute compression of each cylinder in an internal combustion engine having known ideal performance parameters and consists of the following steps: sensing the absolute angular speed of the crankshaft of an engine during at least one noncombustive engine cycle; relating particular subcyclic absolute speed variations to particular cylinders; calculating the work of

Timmerman

1986-01-01

69

Solar Week Friday: Blog  

NSDL National Science Digital Library

This is a reading associated with activities during Solar Week, a twice-yearly event in March and October during which classrooms are able to interact with scientists studying the Sun. Outside of Solar Week, information, activities, and resources are archived and available online at any time. This is a blog entry about the process by which rocket payloads are assembled prior to launch. It was written by one of the female team members associated with a NASA sounding rocket launch program. The blog entry reading is scheduled to occur during Friday of Solar Week.

70

MotorWeek  

ScienceCinema

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."

None

2013-04-19

71

MotorWeek  

SciTech Connect

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."

None

2009-01-01

72

Video Compression  

NASA Technical Reports Server (NTRS)

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.

1996-01-01

73

National Wildlife Week 2002  

NSDL National Science Digital Library

April 7-13, 2002, is Canada's National Wildlife Week. The week, a tribute to conservation pioneer Jack Miner, is an opportunity for citizens to "celebrate wildlife and take action to protect wild plants and animals." In addition to a calendar of events across Canada, the celebration's home page features 20 things that anyone can do to protect wildlife, as well as games, activities, and fact sheets focused on this year's theme -- Climate Change.

2001-01-01

74

Performance of double effect absorption compression cycles for air-conditioning using methanol–TEGDME and TFE–TEGDME systems as working pairs  

Microsoft Academic Search

The organic working pairs trifluoroethanol (TFE)–tetraethyleneglycol dimethyether (TEGDME or E181) and methanol–TEGDME have some advantages over classical water–LiBr and ammonia water working pairs in absorption cycles. One of the most important features is the wide working range caused by the absence of crystallization, the low freezing temperatures of the refrigerants and the thermal stability of the mixtures at high temperatures.The

D Boer; M Valles; A Coronas

1998-01-01

75

Astronomical Data Compression: Algorithms and Architectures  

NASA Astrophysics Data System (ADS)

Digital data is the lifeblood of astronomy. Data compression deals with its efficient representation and transport. As focal planes become more crowded and observing cadences more rapid, ever increasing pressure will be applied to realize near-optimum performance. A typical observational workflow comprises many network links and storage nodes, multiplying the advantage of compression dramatically. Recent work on astronomical data compression has focused on the FITS tile compression convention (http://heasarc.gsfcnasa.gov/fitsio/fpack). This birds-of-a-feather session began a broader discussion of compression-aware astronomical data handling architectures, including compression techniques and algorithms appropriate to binary and ASCII catalogs as well as to imaging data.

Seaman, R.; Pence, W.; White, R.; Gaudet, S.

2010-12-01

76

Practical Java Card bytecode compression 1  

Microsoft Academic Search

Our work concerns bytecode compression on an embedded, tiny and safe environment, and more specif- ically JAVA CARDS. (2) and (4) propose a way to compress java card bytecode into a format executable in an ultra light embedded system, using macro-packing. Our implementation, improved with new specical algorithms, allows a better compress rate (up to 32%). In a smart card

Gabriel Bizzotto; Gilles Grimaud

2002-01-01

77

Conductor For The Week  

NSDL National Science Digital Library

Now that you are enrolled in seminary, it\\'s time to learn how to lead music! You\\'re assignment for the next trimester is to lead the music for one week. You will receive a handout designating which week. Imagine you have been selected by the Boston Pops orchestra to be the guest conductor for one song at the performance tomorrow night. They arent sure which song theyll have you conduct. You must prepare yourself to lead by becoming familiar with the time signature, the beat and ...

Iii, Professor E.

2005-11-28

78

IMAGE: Weekly Problem Archive  

NSDL National Science Digital Library

This is the Image for Magnetopause-to-Auroral Global Exploration (IMAGE) archive of weekly math, science, reading and art problems. New problems involving near-Earth space technology are emailed to participating teachers each week on Tuesday. The problems can be used in related lessons or as extra credit assignments. This web page is part of the outreach program of the IMAGE Satellite team to give teachers and students the latest information about aurora and the study of Earth's magnetic field, along with many programs that IMAGE has developed or participated in with NASA. A pdf document of extra credit problems is also available at this site.

Odenwald, Sten

79

Functional outcome after experimental cauda equina compression.  

PubMed

Spinal nerve roots often sustain compression injuries. We used a Wistar rat model of the cauda equina syndrome to investigate such injuries. Rapid transient compression of the cauda equina was produced using a balloon catheter. The results were assessed by daily neurological examination and somatosensory evoked potential (SEP) recording before surgery and ten weeks after decompression. Compression of the spinal nerves induced changes in the SEP which persisted for up to ten weeks after decompression, but it had no effect on the final neurological outcome. Our study shows the importance of early surgical decompression for cauda equina syndrome. PMID:9250763

Sayegh, F E; Kapetanos, G A; Symeonides, P P; Anogiannakis, G; Madentzidis, M

1997-07-01

80

Visible Embryo: 14 weeks  

NSDL National Science Digital Library

a comprehensive resource of information on human development at 14 weeks of gestation (80-90mm, 25g), designed for both medical student and interested lay people. The Visible Embryo offers a detailed pictorial account of normal and abnormal development. This is a subset of a larger site.

Carmen Arbona (Mouseworks)

2006-10-31

81

Brain Awareness Week  

NSDL National Science Digital Library

Brain Awareness Week (BAW) is an inspirational global campaign that unites those who share an interest in elevating public awareness about the progress and benefits of brain and nervous system research. BAW focuses international attention on the field of neuroscience and offers opportunities for teachers and students to engage in fun educational activities.

Sf (Society for Neuroscience)

2005-05-01

82

Visible Embryo: 26 weeks  

NSDL National Science Digital Library

a comprehensive resource of information on human development at 26 weeks of gestation, designed for both medical student and interested lay people. The Visible Embryo offers a detailed pictorial account of normal and abnormal development. This is a subset of a larger site.

Carmen Arbona (Mouseworks)

2006-11-01

83

Compression pylon  

NASA Technical Reports Server (NTRS)

A compression pylon for an aircraft with a wing-mounted engine, that does not cause supersonic airflow to occur within the fuselage-wing-pylon-nacelle channel is presented. The chord length of the pylon is greater than the local chord length of the wing to which it is attached. The maximum thickness of the pylon occurs at a point corresponding to the local trailing edge of the wing. As a result, the airflow through the channel never reaches supersonic velocities.

Patterson, James C., Jr. (inventor)

1989-01-01

84

Earth Science Week  

NSDL National Science Digital Library

The American Geological Institute organizes Earth Science Week (ESW) each year in October "to help the public gain a better understanding and appreciation for the Earth Sciences and to encourage stewardship of the Earth." The website offers highlights, evaluations, and news clippings of past ESW events. During the months leading up to ESW, users can search for Earth Science events taking place in their area. Teachers can find numerous classroom activities for grades K-12 based in the National Science Education Standards. Students can learn about contests, discover how to earn an ESW Activity Patch, and take the Geosciences Career Webquest. By either subscribing to the _Earth Science Week Update_ newsletter or reading the online version, visitors can find the latest plans for the occasion as well as earth science-related activities, websites, and other events.

85

BusinessWeek Online  

NSDL National Science Digital Library

_Business Week_, published by the McGraw Hill Companies, has recently made its web debut. The site is highlighted by the full text of articles from the print magazine. Also included are a selected browsable archive back to late 1995; a daily briefing section (frames based), with concise summaries of news and market information including performance information on new IPOs (initial public offerings); BW Plus, with topical information on such issues as the best business schools, mutual funds, and women in business; a computer buying guide; and an interactive portfolio manager. A complete five-year searchable archive (fee based) will soon be available.

1995-01-01

86

Iran Weekly Press Digest  

NSDL National Science Digital Library

The Iran Weekly Press Digest, a weekly review of the Iranian press in English, contains a number of articles on the summit of the Organisation of the Islamic Conference and its significance for Iran in its archived and current issues. The eighth summit of the Organisation of the Islamic Conference was recently held in Tehran, Iran. Iran recently hosted representatives from 55 countries to a three-day Muslim summit in Tehran in a move which is being seen as a new phase in the country's re-emergence after years of relative isolation. The acceptance of Iran's invitations by senior figures from former enemies such as Saudi Arabia and Iraq has been portrayed by Iranian leaders and many others as a strong setback for US attempts to politically quarantine that country. Representatives considered 142 resolutions prepared by foreign ministers on issues including Middle East peace, regional conflicts, terrorism and human rights. However, perhaps the most significant outcome of the summit has been a reintroduction of Iran into the Muslim community of nations. Capitalizing on current anti-American sentiments and the recent election of a relatively moderate president, Iran hopes to rebuild its relationships with its neighbors and once again become a regional leader, a position it held for approximately 3000 years.

1997-01-01

87

Explosive Axial Magnetic Flux Compression Generator Armature Material Strength and Compression Effects  

Microsoft Academic Search

The expansion of the armature of an axial magnetic flux compression generator results in an increase in the armature's electrical resistivity and possible melting due to compression and plastic work heating. If melting occurs, further flux compression is impaired by a greatly enhanced Rayleigh-Taylor instability. Even without melting, the expansion process can become unstable, with the armature fragmenting by plastic

E. L. Ruden; G. F. Kiuttu; R. E. Peterkin; J. B. Chase

2004-01-01

88

Compression of echocardiographic scan line data using wavelet packet transform  

NASA Technical Reports Server (NTRS)

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.

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

2001-01-01

89

Compressive beamforming.  

PubMed

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

Xenaki, Angeliki; Gerstoft, Peter; Mosegaard, Klaus

2014-07-01

90

Maxwell's demon and data compression  

NASA Astrophysics Data System (ADS)

In an asymmetric Szilard engine model of Maxwell's demon, we show the equivalence between information theoretical and thermodynamic entropies when the demon erases information optimally. The work gain by the engine can be exactly canceled out by the work necessary to reset the demon's memory after optimal data compression in the manner of Shannon before the erasure.

Hosoya, Akio; Maruyama, Koji; Shikano, Yutaka

2011-12-01

91

Maxwell's demon and data compression.  

PubMed

In an asymmetric Szilard engine model of Maxwell's demon, we show the equivalence between information theoretical and thermodynamic entropies when the demon erases information optimally. The work gain by the engine can be exactly canceled out by the work necessary to reset the demon's memory after optimal data compression in the manner of Shannon before the erasure. PMID:22304050

Hosoya, Akio; Maruyama, Koji; Shikano, Yutaka

2011-12-01

92

The First Week  

NSDL National Science Digital Library

During the first week of class, strive to create an atmosphere of mutual trust and respect. This gives the students a chance to get to know you as a person, and you will also get to know them in the process. A key challenge is to make students feel comfortable with science, which many view as difficult to understand and unimportant to their daily lives. The variety of inquiry-based writing assignments and activities described in this section will help students build confidence in their abilities and convince them of the relevance of science. This free selection from the series, How to... Write to Learn Science includes the Table of Contents and two bonus sections.

Tierney, Bob; Dorroh, John

2004-01-01

93

FRESCO: Referential compression of highly similar sequences.  

PubMed

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

Wandelt, Sebastian; Leser, Ulf

2013-01-01

94

Pregnancy Calendar: A Week-by-Week Guide  

MedlinePLUS

... Parents Are Reading Q&A: Obamacare Finding Affordable Health Care Eating Well & Staying Fit Flu Vaccine: How Many Doses? Connect With Us: Social Media Pregnant? Your Baby's Growth A Week-by-Week ...

95

Secondary Disadvantaged--Six Weeks of Work-Experience and Counseling for BOCES Occupational Education Minimal-Achieving Students (Project: VEA CO-75-4A-1006); Evaluation Report.  

ERIC Educational Resources Information Center

Known also as the Summer Minimal Achiever Rehabilitation Training Program (SMART), the Nassau County work-experience program was designed to motivate minimal achieving students toward more positively directed goals. Of the more than 300 students referred to the program, 142 were accepted as enrollees. Program objectives were: (1) to provide…

La Sala, Vincent J; Picarelli, Henry E.

96

Compressing DNA sequence databases with coil  

PubMed Central

Background Publicly available DNA sequence databases such as GenBank are large, and are growing at an exponential rate. The sheer volume of data being dealt with presents serious storage and data communications problems. Currently, sequence data is usually kept in large "flat files," which are then compressed using standard Lempel-Ziv (gzip) compression – an approach which rarely achieves good compression ratios. While much research has been done on compressing individual DNA sequences, surprisingly little has focused on the compression of entire databases of such sequences. In this study we introduce the sequence database compression software coil. Results We have designed and implemented a portable software package, coil, for compressing and decompressing DNA sequence databases based on the idea of edit-tree coding. coil is geared towards achieving high compression ratios at the expense of execution time and memory usage during compression – the compression time represents a "one-off investment" whose cost is quickly amortised if the resulting compressed file is transmitted many times. Decompression requires little memory and is extremely fast. We demonstrate a 5% improvement in compression ratio over state-of-the-art general-purpose compression tools for a large GenBank database file containing Expressed Sequence Tag (EST) data. Finally, coil can efficiently encode incremental additions to a sequence database. Conclusion coil presents a compelling alternative to conventional compression of flat files for the storage and distribution of DNA sequence databases having a narrow distribution of sequence lengths, such as EST data. Increasing compression levels for databases having a wide distribution of sequence lengths is a direction for future work.

White, W Timothy J; Hendy, Michael D

2008-01-01

97

Inverse-pinch flux compression generator  

Microsoft Academic Search

Summary form only given. In this work, a non-explosive flux compression generator was designed, built and tested. The device is based on an inverse-Z-pinch plasma discharge which is used as the piston field in compressing the seed poloidal magnetic field. The feasibility of non-explosive flux compression generators in driving high impedance loads was demonstrated in an earlier experiment where a

J. B. Javedani; D. E. Lileikis; G. F. Kiuttu; J. H. Degnan; P. J. Turchi; J. D. Graham

1997-01-01

98

30 CFR 77.412 - Compressed air systems.  

Code of Federal Regulations, 2013 CFR

...Compressed air systems. 77.412...Mineral Resources MINE SAFETY AND HEALTH...DEPARTMENT OF LABOR COAL MINE SAFETY AND...SURFACE COAL MINES AND SURFACE WORK...OF UNDERGROUND COAL MINES Safeguards for...Compressed air systems....

2013-07-01

99

Turbulence in Compressible Flows  

NASA Technical Reports Server (NTRS)

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.

1997-01-01

100

75 FR 70999 - National Entrepreneurship Week, 2010  

Federal Register 2010, 2011, 2012, 2013

...Entrepreneurs embody the promise that lies at the heart of America--that if you have a good idea and work hard enough, the American dream is within your reach. During National Entrepreneurship Week, we renew our commitment to supporting the...

2010-11-19

101

Compression ignition characteristics of coal slurry fuels  

Microsoft Academic Search

Slow and medium speed compression ignition engines are devices with the potential for conversion to coal fueling. Recent work focuses on coal slurried in a liquid carrier. Engine studies on coal slurry to date have investigated the slurries' wear, thermal efficiency, and injection performance. Previously lacking information on the compression ignition characteristics of coal slurries, specifically, the ignition delay times

Brehob

1985-01-01

102

[Weekly paclitaxel therapy is curative for patients with retroperitoneal liposarcoma].  

PubMed

In March 2004, we resected a giant retroperitoneal liposarcoma and the transverse colon, spleen and left kidney in a 58-year-old woman. In July, recurrence was detected in the right pelvis and left upper abdomen; therefore, we resected the tumor. In September 2004, computed tomography (CT) revealed multiple recurrences in the right lower abdomen, left upper abdomen, front of the left lobe of the liver, and at the back of the stomach. In October 2004, we started mesna, doxorubicin, ifosfamide, and dacarbazine therapy (MAID); however, after 1 course, the disease progressed, and the patient developed edema in the bilateral legs due to inferior vena cava (IVC) compression. In November 2004, we started weekly paclitaxel therapy (100 mg/m(2), once a week for 3 weeks followed by 1 drug-free week). CT revealed no change as a result of chemotherapy; however, IVC compression had improved, and leg edema had decreased. In August 2005, chemotherapy was stopped; therefore,the patient's condition worsened. She died in September 2005. We performed weekly paclitaxel therapy for the patient with recurrent liposarcoma. This improved her symptoms and quality of life (QOL). Therefore,we consider weekly paclitaxel therapy to be effective for liposarcoma treatment. PMID:17353645

Yoshida, Yasushi; Inoue, Katsuhiko; Ohsako, Tomofumi; Nagamoto, Nobuhide; Tanaka, Eiji; Tsuruzoe, Shu

2007-03-01

103

Compression of peat soils  

SciTech Connect

One-dimensional compression of peat is characterized using a simple rheological model in which the structural viscosity is assumed to be linear. This model utilizes three empirical parameters pertaining to the primary compression, secondary compression, and the rate of secondary compression. Based on the analysis of 43 laboratory and 10 field compression-time data, it is found that the primary and secondary compressibility parameters depend on the stress level and therefore can be determined in the laboratory. However, the values obtained in the laboratory tend to overestimate the field rate of compression and underestimate the magnitude of secondary compression. These parameters must be corrected for the effects of the non-linearity of peat behavior for accurate field prediction. Successful field predictions also require consideration of other important factors such as deviations from one-dimensional compression conditions, decomposition, vertical and lateral variability, and temperature effects. The compression behavior of precompressed peat under the final stress (reduced load) is affected by the amount of preloading ratio (ratio of the surcharge stress to the final stress). The magnitudes of primary, secondary, and tertiary compressibility parameters increase as the magnitude of the final stress increases relative to the surcharge stress while the viscosity of peat structure during secondary and tertiary compressions becomes smaller. The available criteria for selecting the surcharge stress application period developed for clay soils are not directly applicable to peat soils. A method to determine the compression parameters of peat using a constant rate of strain triaxial compression test is developed.

Mochtar, N.E.

1985-01-01

104

Extended testing of compression distillation.  

NASA Technical Reports Server (NTRS)

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.

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

1972-01-01

105

Data compression using Chebyshev transform  

NASA Technical Reports Server (NTRS)

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.

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

2007-01-01

106

Bloomberg Business Week: Small Business  

NSDL National Science Digital Library

Created by Business Week magazine, Business Week Frontier is a new resource center for small business owners. The News Center covers current issues from the perspective of small business owners and an array of columns provide advice, website recommendations, and book excerpts. Other resources include financial calculators, a glossary of terms, and market research links.

1999-01-01

107

This Week in the History of Psychology  

NSDL National Science Digital Library

Written and produced by Professor Christopher D. Green of York University, "This Week in the History of Psychology" is a delightful and engaging podcast series. Its intended audience is students in university level courses on the history of psychology, but a wide variety of persons will find the work here compelling. Each week Professor Green has an interview with an expert who talks about a key event from the annals of psychology. The interviews begin with a short overview of said event, along with a celebration of the week's birthdays and other related anniversaries from the world of psychology. Currently the site has several dozen interviews, including discussions on Freud's only trip to the United States and Emil Kraeplelin, the man behind the modern categories of mental illness.

Green, Christopher D.

108

The Effect of Compressibility on Barotropic and Baroclinic Instability.  

NASA Astrophysics Data System (ADS)

The effect of compressibility on two-dimensional barotropic and baroclinic growth rates is examined by means of a linearized nonhydrostatic compressible model. It is shown that the growth rates are diminished when compressibility is included because perturbation internal energy resents a sink of basic-state kinetic energy when work is done to compress the medium. Nonlinear simulations provided by compressible and incompressible versions of the ZETA model show that the solutions are nearly identical, but the compressible solution develops more slowly than the incompressible one, consistent with the linear analysis.

Gross, Brian D.

1997-01-01

109

Comparison of the effectiveness of compression stockings and layer compression systems in venous ulceration treatment  

PubMed Central

Introduction The aim of the research was to compare the dynamics of venous ulcer healing when treated with the use of compression stockings as well as original two- and four-layer bandage systems. Material and methods A group of 46 patients suffering from venous ulcers was studied. This group consisted of 36 (78.3%) women and 10 (21.70%) men aged between 41 and 88 years (the average age was 66.6 years and the median was 67). Patients were randomized into three groups, for treatment with the ProGuide two-layer system, Profore four-layer compression, and with the use of compression stockings class II. In the case of multi-layer compression, compression ensuring 40 mmHg blood pressure at ankle level was used. Results In all patients, independently of the type of compression therapy, a few significant statistical changes of ulceration area in time were observed (Student’s t test for matched pairs, p < 0.05). The largest loss of ulceration area in each of the successive measurements was observed in patients treated with the four-layer system – on average 0.63 cm2/per week. The smallest loss of ulceration area was observed in patients using compression stockings – on average 0.44 cm2/per week. However, the observed differences were not statistically significant (Kruskal-Wallis test H = 4.45, p > 0.05). Conclusions A systematic compression therapy, applied with preliminary blood pressure of 40 mmHg, is an effective method of conservative treatment of venous ulcers. Compression stockings and prepared systems of multi-layer compression were characterized by similar clinical effectiveness.

Jawien, Arkadiusz; Cierzniakowska, Katarzyna; Cwajda-Bialasik, Justyna; Moscicka, Paulina

2010-01-01

110

Collapse Mechanism of Foam Cored Sandwich Structures Under Compressive Load  

Microsoft Academic Search

In this work the moisture absorption capability, compressive properties, collapse modes of various types of composite sandwich structures are reported. The tested sandwich structures were constructed with varieties of hybridized skin materials and different compositions of the core materials. The moisture absorption, Flatwise compression and Edgewise compression tests are conducted for core as well as sandwich structures. Comparisons of results

S. Manjunath Yadav; K. V. Arun; S. Basavarajappa; Narendranath S; Santosh Kumar

2011-01-01

111

Deformation: Nanocomposite Compression  

NSDL National Science Digital Library

Students learn about nanocomposites, compression and strain as they design and program robots that compress materials. Student groups conduct experiments to determine how many LEGO® MINDSTORMS® NXT motor rotations it takes to compress soft nanocomposites, including mini marshmallows, Play-Doh®, bread and foam. They measure the length and width of their nanocomposite objects before and after compression to determine the change in length and width as a function of motor rotation.

Applying Mechatronics to Promote Science (AMPS) GK-12 Program,

112

Towards Compressing Web Graphs  

Microsoft Academic Search

Abstract We consider the problem of compressing graphs of the link structure of the World Wide Web. We provide efficient algorithms for such compression that are motivated by recently proposed random graph models for describing the Web. The algorithms are based on reducing the compression problem to the problem of finding a minimum,spanning tree in a directed graph related to

Micah Adler; Michael Mitzenmacher

2001-01-01

113

On compressing social networks  

Microsoft Academic Search

Motivated by structural properties of the Web graph that support efficient data structures for in memory adjacency queries, we study the extent to which a large network can be compressed. Boldi and Vigna (WWW 2004), showed that Web graphs can be compressed down to three bits of storage per edge; we study the compressibility of social networks where again adjacency

Flavio Chierichetti; Ravi Kumar; Silvio Lattanzi; Michael Mitzenmacher; Alessandro Panconesi; Prabhakar Raghavan

2009-01-01

114

Prelude to compressed baryonic matter  

NASA Astrophysics Data System (ADS)

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.

Wilczek, Frank

115

Math Problems of the Week  

NSDL National Science Digital Library

Math Problems of the Week are activities, with student handouts, that can be used to help students develop, formalize, and reflect on their problem-solving strategies. Membership subscription is required to access most resources.

116

Adult Learners' Week in Australia.  

ERIC Educational Resources Information Center

Promotional materials and activities for Australia's Adult Learners Week, which are shaped by a variety of stakeholders , include media strategies and a website. Activities are evaluated using a market research company and website and telephone hotline statistics. (SK)

Cross, John

2002-01-01

117

Cool Robot of the Week  

NSDL National Science Digital Library

File this one under "super neat." Anyone with even the slightest interest in robots and robotics should enjoy this page, produced by the NASA Space Telerobotics Program. Each week, Cool Robot adds a new link with a short description of the featured site or a news story concerning a breakthrough in robotic technology or an innovative solution to robotics problems. Archives dating back to May 1996 are included at the site. Bookmark this one, and pay a weekly visit; I know I will.

Lavery, Dave.

118

Median Nerve Trauma in a Rat Model of Work-Related Musculoskeletal Disorder  

PubMed Central

Anatomical and physiological changes were evaluated in the median nerves of rats trained to perform repetitive reaching. Motor degradation was evident after 4 weeks. ED1-immunoreactive macrophages were seen in the transcarpal region of the median nerve of both forelimbs by 5–6 weeks. Fibrosis, characterized by increased immunoexpression of collagen type I by 8 weeks and connective tissue growth factor by 12 weeks, was evident. The conduction velocity (NCV) within the carpal tunnel showed a modest but significant decline after 9–12 weeks. The lowest NCV values were found in animals that refused to participate in the task for the full time available. Thus, both anatomical and physiological signs of progressive tissue damage were present in this model. These results, together with other recent findings indicate that work-related carpal tunnel syndrome develops through mechanisms that include injury, inflammation, fibrosis and subsequent nerve compression.

CLARK, BRIAN D.; BARR, ANN E.; SAFADI, FAYEZ F.; BEITMAN, LISA; AL-SHATTI, TALAL; AMIN, MAMTA; GAUGHAN, JOHN P.; BARBE, MARY F.

2006-01-01

119

The New CCSDS Image Compression Recommendation  

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

120

Solid iron compressed up to 560 GPa.  

PubMed

Dynamic compression by multiple shocks is used to compress iron up to 560 GPa (5.6 Mbar), the highest solid-state pressure yet attained for iron in the laboratory. Extended x-ray absorption fine structure (EXAFS) spectroscopy offers simultaneous density, temperature, and local-structure measurements for the compressed iron. The data show that the close-packed structure of iron is stable up to 560 GPa, the temperature at peak compression is significantly higher than expected from pure compressive work, and the dynamic strength of iron is many times greater than the static strength based on lower pressure data. The results provide the first constraint on the melting line of iron above 400 GPa. PMID:23971582

Ping, Y; Coppari, F; Hicks, D G; Yaakobi, B; Fratanduono, D E; Hamel, S; Eggert, J H; Rygg, J R; Smith, R F; Swift, D C; Braun, D G; Boehly, T R; Collins, G W

2013-08-01

121

Comparison of Artificial Compressibility Methods  

NASA Technical Reports Server (NTRS)

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.

Kiris, Cetin; Housman, Jeffrey; Kwak, Dochan

2003-01-01

122

75 FR 58281 - National Farm Safety and Health Week, 2010  

Federal Register 2010, 2011, 2012, 2013

...globe. As we celebrate National Farm Safety and Health Week, we...procedures. Additionally, farms and ranches with children or...safety instruction to prevent injury or illness. By working together...September 25, 2010, as National Farm Safety and Health Week. I...

2010-09-23

123

Weekly Compilation of Presidential Documents  

NSDL National Science Digital Library

"The Weekly Compilation of Presidential Documents is published every Monday by the Office of the Federal Register, National Archives and Records Administration and contains statements, messages, and other Presidential materials released by the White House during the preceding week." This new online version is a pilot project designed to provide the public with easier access to Presidential documents. The site is searchable and contains documents from January 6, 1997 to the present. Search returns offer document summaries and as well as full-text in ascii or .pdf formats.

President., United S.

1998-01-01

124

Plasma heating by electric field compression.  

PubMed

Plasma heating by compression of electric fields is proposed. It is shown that periodic cycles of external compression followed by the free expansion of electric fields in the plasma cause irreversible, collisionless plasma heating and corresponding entropy generation. As a demonstration of general ideas and scalings, the heating is shown in the case of a dusty plasma, where electric fields are created due to the presence of charged dust. The method is expected to work in the cases of compression of low frequency or dc electric fields created by other methods. Applications to high power laser heating of plasmas using this scheme are discussed. PMID:24856702

Avinash, K; Kaw, P K

2014-05-01

125

Plasma Heating by Electric Field Compression  

NASA Astrophysics Data System (ADS)

Plasma heating by compression of electric fields is proposed. It is shown that periodic cycles of external compression followed by the free expansion of electric fields in the plasma cause irreversible, collisionless plasma heating and corresponding entropy generation. As a demonstration of general ideas and scalings, the heating is shown in the case of a dusty plasma, where electric fields are created due to the presence of charged dust. The method is expected to work in the cases of compression of low frequency or dc electric fields created by other methods. Applications to high power laser heating of plasmas using this scheme are discussed.

Avinash, K.; Kaw, P. K.

2014-05-01

126

Compressed Gas Safety for Experimental Fusion Facilities  

SciTech Connect

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.

Lee C. Cadwallader

2004-09-01

127

Compressive Sensing DNA Microarrays  

Microsoft Academic Search

Abstract—Compressive,Sensing Microarrays,(CSM) are DNA- based sensors that operate,using group,testing and,compressive sensing (CS) principles. In contrast to conventional DNA microar- rays, 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,compressive,sensing theory and,the biochemistry,of

Wei Dai; Mona A. Sheikh; Olgica Milenkovic; Richard G. Baraniukyy

2009-01-01

128

Evolved image compression transforms  

NASA Astrophysics Data System (ADS)

State-of-the-art image compression and reconstruction schemes utilize wavelets. Quantization and thresholding are commonly used to achieve additional compression, but cause permanent, irreversible information loss. This paper describes an investigation into whether evolutionary computation (EC) may be used to optimize forward (compression-only) transforms capable of matching or exceeding the compression capabilities of a selected wavelet, while reducing the aggregate error in images subsequently reconstructed by that wavelet. Transforms are independently trained and tested using three sets of images: digital photographs, fingerprints, and satellite images.

Aldridge, Shawn; Babb, Brendan; Moore, Frank; Peterson, Michael

2010-04-01

129

Motor Development International: Compressed Air Technology Systems  

NSDL National Science Digital Library

How does a car that boasts "zero pollution" and even "cleans the air it uses" work? This website provides information on the air compression cars developed by Motor Development International. Aside from the general overview of the mechanics of air compression, the FAQ section provides additional information on the air tanks, filter system, body frame, electric system and MDI's business model. A key target for this website seems to be potential buyers and investors.

130

[Compressibility of directly compressed forms of lactitol].  

PubMed

Lactitol ranks among sugar alcohols which are employed as dry binders in the manufacture of tablets, particularly the chewable ones. Water-granulated lactitol is the directly compacting form of this substance. The present paper studies the compressibility of the granulated form of lactitol and the effects of different concentrations of the lubricant magnesium stearate on the strength and disintegration time of the compacts from his substance. Lactitol cannot be compressed without an added lubricant. Magnesium stearate, employed in two concentrations, 0.4% and 0.8%, did not negatively interfere with the strength of the compacts. The disintegration period of tablets was prolonged with increasing stearate concentration, but independently of compression force. PMID:14619701

Muzíková, J

2003-09-01

131

Six Week Slavery Novel Unit.  

ERIC Educational Resources Information Center

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:…

Jones, Darolyn Lyn

132

78 FR 37423 - National Small Business Week, 2013  

Federal Register 2010, 2011, 2012, 2013

...National Small Business Week, 2013 Proclamation 8995--World Elder Abuse Awareness...cut taxes for small businesses 18 times, broadened...products all over the world. Every step of the...Government work better for business through...

2013-06-20

133

76 FR 58711 - National Farm Safety and Health Week, 2011  

Federal Register 2010, 2011, 2012, 2013

...generated by our agricultural sector are vital to America's 21st-century economy. Farmers represent the best of the American dream-- passing on proud traditions of hard work and commitment to their children. This week, we celebrate...

2011-09-21

134

77 FR 58297 - National Farm Safety and Health Week, 2012  

Federal Register 2010, 2011, 2012, 2013

...producers who rise before the dawn, entrepreneurs who bring ideas to market, and working men and women who build the American dream with their bare hands. This week, we honor their tireless efforts and rededicate ourselves to equipping our...

2012-09-19

135

Bilateral brachial plexus compressive neuropathy (crutch palsy).  

PubMed

Brachial plexus compressive neuropathy following the use of axillary crutches (crutch palsy) is a rare but well-recognized entity. Most reported cases involve the posterior cord of the brachial plexus in children and have resolved spontaneously within 8-12 weeks. We recently treated a 36-year-old man who was using axillary crutches for mobilization after a supracondylar femoral fracture. Bilateral posterior cord (predominantly radial nerve) compressive neuropathy subsequently developed, with lesser involvement of the ulnar and median nerves. The patient had little to no improvement clinically 8 weeks after the estimated onset of the palsy, and an electromyogram at that time confirmed the presence of a severe axonotmesis lesion of the radial, median, and ulnar nerves bilaterally. The patient was treated with static cock-up wrist splinting and discontinuation of the axillary crutches. Return of sensory and motor function was delayed but occurred within 9 months. PMID:9057152

Raikin, S; Froimson, M I

1997-01-01

136

Morphological changes in compressible foams  

NASA Astrophysics Data System (ADS)

We discuss statistical and morphological properties of foams with compressible ideal gas within the bubbles. Usually in the mechanics of foams it is assumed that gas within the bubbles is incompressible. However, if we admit a compressible gas, and if we consider the full range of parameters, so that the surface tension energy is comparable to the work required to compress or expand a bubble, a variety of new phenomena arise. Principal among these is a transition to morphologies that are quite different from those seen with incompressible foams. For small compressibility, all bubbles of the foam are of comparable size. As compressibility becomes larger, a, large number of the bubbles collapse and form clusters of very small bubbles, which are immersed in a background of a few very big bubbles. We present the results of a numerical and analytical study of the behavior of compressible foams for various physical conditions. We derive the expression for the free energy, and prove the equation of state using two different approaches: one based on methods from statistical physics, the other based on differential geometry. We discuss two different states of a foam. In one state, where the surface tension is small compared with the compressibility of gas, the foam is in a relatively uniform configuration. We discuss two different approximations of the equation of state for this type of configurations. We show why uniform configurations lose stability when the parameters of the foam reach a certain limit. We show that the geometrical instability causes a morphological change analogous to a phase transition that leads to a nonuniform configuration (the second possible state), and give a qualitative description of this transition. We introduce a model free energy, assuming the bubbles in the foam to come in just two sizes and calculate its global minimum for different values of the parameters. We then consider the transition in more detail and show how some subtle factors of the foam's structure and the parameters of the numerical simulations influence the properties of the transformation and the statistics of the foam in the nonuniform state.

Vainchtein, Dmitri Leonidovich

137

29 CFR 3.4 - Submission of weekly statements and the preservation and inspection of weekly payroll records.  

Code of Federal Regulations, 2013 CFR

...completion of the contract. The payroll records shall set out accurately and completely the name and address of each laborer and mechanic, his correct classification, rate of pay, daily and weekly number of hours worked, deductions made, and actual...

2013-07-01

138

Compressive Underwater Video Camera.  

National Technical Information Service (NTIS)

The primary long-term goal of our research team is the development of image compression transforms with high compression ratios (consistently exceeding 200:1) that can facilitate the transmission of moderate resolution imagery (e.g., S-VHS format) across ...

F. M. Caimi G. X. Ritter M. S. Schmalz

1998-01-01

139

Compression Ratio Adjuster  

NASA Technical Reports Server (NTRS)

New mechanism alters compression ratio of internal-combustion engine according to load so that engine operates at top fuel efficiency. Ordinary gasoline, diesel and gas engines with their fixed compression ratios are inefficient at partial load and at low-speed full load. Mechanism ensures engines operate as efficiently under these conditions as they do at highload and high speed.

Akkerman, J. W.

1982-01-01

140

Compressed Facade Displacement Maps  

Microsoft Academic Search

We describe an approach to render massive urban models. To prevent a memory transfer bottleneck, we propose to render the models from a compressed representation directly. Our solution is based on rendering crude building outlines as polygons and generating details by ray-tracing displacement maps in the fragment shader. We demonstrate how to compress a displacement map so that a decompression

Saif Ali; Jieping Ye; Anshuman Razdan; Peter Wonka

2009-01-01

141

LZAC Lossless Data Compression  

Microsoft Academic Search

Summary form only given. This paper presents LZAC, a new universal lossless data compression algorithm derived from the popular and widely used LZ77 family. The objective of LZAC is to improve the compression ratios of the LZ77 family while still retaining the family's key characteristics: simple, universal and fast in decoding and economical in memory consumption. LZAC presents two new

Allan Chu

2002-01-01

142

Fractal image compression  

NASA Technical Reports Server (NTRS)

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.

Barnsley, Michael F.; Sloan, Alan D.

1989-01-01

143

Scalable Communication Trace Compression  

SciTech Connect

Characterizing the communication behavior of parallel programs through tracing can help understand an application’s characteristics, model its performance, and predict behavior on future systems. However, lossless communication traces can get prohibitively large, causing programmers to resort to variety of other techniques. In this paper, we present a novel approach to lossless communication trace compression. We augment the sequitur compression algorithm to employ it in communication trace compression of parallel programs. We present optimizations to reduce the memory overhead, reduce size of the trace files generated, and enable compression across multiple processes in a parallel program. The evaluation shows improved compression and reduced overhead over other approaches, with up to 3 orders of magnitude improvement for the NAS MG benchmark. We also observe that, unlike existing schemes, the trace files sizes and the memory overhead incurred are less sensitive to, if not independent of, the problem size for the NAS benchmarks.

Krishnamoorthy, Sriram; Agarwal, Khushbu

2010-05-17

144

Astronomy Week in Madeira, Portugal  

NASA Astrophysics Data System (ADS)

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.

Augusto, P.; Sobrinho, J. L.

2012-05-01

145

Observation of the Week Archive  

NSDL National Science Digital Library

In its early years NASA's Observatorium (described in the January 10, 1997 Scout Report) posted an "observation of the week" in one of the following broad categories: earth sciences, sun and the solar system, stars, galaxies, the universe, education, human spaceflight, space technology, or space history. These weekly observations (such as the recent Leonid Meteor storm) are described in general terms and are accompanied by color images and links to recommended sites. Interested viewers may browse the archive (1995 to 1999) for events by subject or date. The simplicity of the site allows for easy access to a wide range of interesting and current information -- whether radar images of Mount Vesuvius, an understanding of Tsunamis, or Galactic Cannibalism.

1995-01-01

146

Classroom Assessment Techniques: Weekly Reports  

NSDL National Science Digital Library

This site describes the use of weekly reports as an assessment tool for student learning. It is one of a series of Classroom Assessment Techniques (CATs) provided by the Field-tested Learning Assessment Guide (FLAG) website. The CATs of FLAG were constructed as a resource for science, technology, engineering and mathematics instructors to emphasize deeper levels of learning and to give instructors valuable feedback during a course. Weekly reports provide rapid feedback about what students think they are learning and what conceptual difficulties they are experiencing. This site provides an overview of this assessment technique including information about how to use it. The site is also linked to a set of discipline-specific "tools" that can be downloaded for immediate use, as well as supplementary links and sources to further explore this assessment tool.

Etkina, Eugenia; The National Institute for Science Education; College Level One Team

147

On the aerosol weekly cycle spatiotemporal variability over Europe  

NASA Astrophysics Data System (ADS)

In this work, we focus on the spatial and temporal variability of the aerosol weekly cycle over Europe as these were recorded from TERRA MODIS and AQUA MODIS satellite instruments. Aerosol optical properties retrieved from MODIS TERRA (February 2000-February 2009) and AQUA (July 2002-December 2008) were used to produce an aerosol weekly cycle index. First, the general aerosol optical depth (AOD550 nm) weekly patterns were defined at a 1° × 1° resolution using the satellite-based index and six regions of interest were selected. To remove episodic dust transport events, two different aerosol flags, employing fine mode ratio (FMR550 nm) and AOD550 nm data, were applied diagnostically, showing that the observed weekly cycles over Europe are due to continental aerosols. A second spatial averaging method was then used for the investigation of the weekly variability and the statistical significance of the weekly cycle over each of the previously selected regions. Three major weekly cycle plumes are observed over Europe. A strong positive (higher values during midweek) weekly cycle plume appears over Central Europe, while a strong negative (higher values during weekend) weekly plume appears over the Iberian Peninsula and the North-eastern Europe. The temporal examination of the weekly cycles shows that in some areas there are seasonal differences in the sign of the weekly cycle. The aerosol weekly variability over different regions in Europe was examined in conjunction with the dominating synoptic wind patterns from the NCEP/NCAR reanalysis, showing that the seasonal weekly cycle plumes over regions situated in the eastern Europe and the Mediterranean Sea could be partly attributed to the westerly transport of continental aerosols.

Georgoulias, A. K.; Kourtidis, K. A.

2011-05-01

148

Ramp Compression Experiments - a Sensitivity Study  

SciTech Connect

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.

Bastea, M; Reisman, D

2007-02-26

149

Evidence-Based Compression  

PubMed Central

Objective: To summarize the currently published scientific evidence for the venous flow effects of mechanical devices, particularly intermittent pneumatic compression, and the relation to prevention of deep vein thrombosis (DVT). Summary Background Data: While intermittent pneumatic compression is an established method of DVT prophylaxis, the variety of systems that are available can use very different compression techniques and sequences. In order for appropriate choices to be made to provide the optimum protection for patients, the general performance of systems, and physiological effects of particular properties, must be analyzed objectively. Methods: Medline was searched from 1970 to 2002, and all relevant papers were searched for further appropriate references. Papers were selected for inclusion when they addressed specifically the questions posed in this review. Results: All the major types of intermittent compression systems are successful in emptying deep veins of the lower limb and preventing stasis in a variety of subject groups. Compression stockings appear to function more by preventing distension of veins. Rapid inflation, high pressures, and graded sequential intermittent compression systems will have particular augmentation profiles, but there is no evidence that such features improve the prophylactic ability of the system. Conclusions: The most important factors in selecting a mechanical prophylactic system, particularly during and after surgery, are patient compliance and the appropriateness of the site of compression. There is no evidence that the peak venous velocity produced by a system is a valid measure of medical performance.

Morris, Rhys J.; Woodcock, John P.

2004-01-01

150

Hyperspectral Image Compression  

NASA Astrophysics Data System (ADS)

Hyperspectral images gathered by satellites or aerial means provide a vast amount of data for geophysicists. A few applications include the exploration of minerals, research of land pollution, and military surveillance. NASA and other agencies are producing gigabytes of hyperspectral images which need to be transmitted and stored daily. As these images require high compression rates and preservation of data integrity, we are presented with an intriguing compression problem. In our research we investigate two compression algorithms: a near-lossless technique based on minimizing maximum absolute distortion (MAD) and a lossy based algorithm which minimizes mean squared error (MSE). Near-lossless algorithms provide high compression rates and a uniform distribution of error. Whereas MSE based algorithms yield high compression rates but a non-uniform distribution of error. Our goal is to determine which algorithm yields high compression rates and minimal data loss without modifying post processing of hyperspectral data. In order to compare these two compression algorithms and determine their effect on post processing we used ENVI's image processing tools. We classified the decompressed images for each algorithm and compared them to the classified original image.

Wright, Stephanie; Miguel, Agnieszka, , Dr.; Ashbach, Jason

2008-05-01

151

77 FR 69733 - National Family Week, 2012  

Federal Register 2010, 2011, 2012, 2013

...character in their children. This week, we celebrate the unity and compassion...ahead. During National Family Week, let us recommit to keeping America's...proclaim November 18 through November 24, 2012, as National Family Week. I invite all States,...

2012-11-21

152

76 FR 22001 - National Park Week, 2011  

Federal Register 2010, 2011, 2012, 2013

...be waived during National Park Week. All Americans can visit www...have fun. During National Park Week, we reaffirm our need to maintain...proclaim April 16 through April 24, 2011, as National Park Week. I encourage all Americans...

2011-04-20

153

Radio frequency pulse compression  

SciTech Connect

High gradients require peak powers. One possible way to generate high peak powers is to generate a relatively long pulse at a relatively low power and compress it into a shorter pulse with higher peak power. It is possible to compress before dc to rf conversion as is done for the relativistic klystron or after dc to rf conversion as is done with SLED. In this note only radio frequency pulse compression (RFPC) is considered. Three methods of RFPC will be discussed: SLED, BEC, and REC. 3 refs., 8 figs., 1 tab.

Farkas, Z.D.

1988-12-01

154

K.CC Color Week  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: This game can be set up two ways. Version 1 Set up one week as âcolor weekâ and send home a notice to parents laying out each color day. Example: Monda...

155

Compressibility Effects in Aeronautical Engineering  

NASA Technical Reports Server (NTRS)

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.

Stack, John

1941-01-01

156

Micromechanics of composite laminate compression failures  

NASA Technical Reports Server (NTRS)

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.

Guynn, E. Gail; Bradley, Walter L.

1988-01-01

157

Electromagnetically Driven Flux Compression.  

National Technical Information Service (NTIS)

Electromagnetically driven flux compression (EMC) devices are developed with a view to applications for experiments with megagauss fields, in particular for a study of magnetic bremsstrahlung. Fields of the order of 1.3 MG are reproducibly generated by me...

D. Kachilla, F. Herlach, T. Erber

1969-01-01

158

Muon Cooling: Longitudinal Compression  

NASA Astrophysics Data System (ADS)

A 10 MeV/c positive muon beam was stopped in helium gas of a few mbar in a magnetic field of 5 T. The muon "swarm" has been efficiently compressed from a length of 16 cm down to a few mm along the magnetic field axis (longitudinal compression) using electrostatic fields. The simulation reproduces the low energy interactions of slow muons in helium gas. Phase space compression occurs on the order of microseconds, compatible with the muon lifetime of 2 ?s. This paves the way for the preparation of a high-quality low-energy muon beam, with an increase in phase space density relative to a standard surface muon beam of 107. The achievable phase space compression by using only the longitudinal stage presented here is of the order of 104.

Bao, Yu; Antognini, Aldo; Bertl, Wilhelm; Hildebrandt, Malte; Khaw, Kim Siang; Kirch, Klaus; Papa, Angela; Petitjean, Claude; Piegsa, Florian M.; Ritt, Stefan; Sedlak, Kamil; Stoykov, Alexey; Taqqu, David

2014-06-01

159

Hybrid LZW compression  

NASA Technical Reports Server (NTRS)

The Science Data Management and Science Payload Operations subpanel reports from the NASA Conference on Scientific Data Compression (Snowbird, Utah in 1988) indicate the need for both lossless and lossy image data compression systems. The ranges developed by the subpanel suggest ratios of 2:1 to 4:1 for lossless coding and 2:1 to 6:1 for lossy predictive coding. For the NASA Freedom Science Video Processing Facility it would be highly desirable to implement one baseline compression system which would meet both of these criteria. Presented here is such a system, utilizing an LZW hybrid coding scheme which is adaptable to either type of compression. Simulation results are presented with the hybrid LZW algorithm operating in each of its modes.

Lewis, H. Garton, Jr.; Forsyth, William B.

1989-01-01

160

Muon cooling: longitudinal compression.  

PubMed

A 10??MeV/c positive muon beam was stopped in helium gas of a few mbar in a magnetic field of 5 T. The muon "swarm" has been efficiently compressed from a length of 16 cm down to a few mm along the magnetic field axis (longitudinal compression) using electrostatic fields. The simulation reproduces the low energy interactions of slow muons in helium gas. Phase space compression occurs on the order of microseconds, compatible with the muon lifetime of 2???s. This paves the way for the preparation of a high-quality low-energy muon beam, with an increase in phase space density relative to a standard surface muon beam of 10^{7}. The achievable phase space compression by using only the longitudinal stage presented here is of the order of 10^{4}. PMID:24949772

Bao, Yu; Antognini, Aldo; Bertl, Wilhelm; Hildebrandt, Malte; Khaw, Kim Siang; Kirch, Klaus; Papa, Angela; Petitjean, Claude; Piegsa, Florian M; Ritt, Stefan; Sedlak, Kamil; Stoykov, Alexey; Taqqu, David

2014-06-01

161

Tension and Compression  

NSDL National Science Digital Library

Students experience the forces of tension and compression by manipulating objects that are strong in each but not in both and then take what they have learned and apply it to the construction of various structures.

Foundation, Wgbh E.

2004-02-20

162

Vapor Compression Distillation Module.  

National Technical Information Service (NTIS)

A Vapor Compression Distillation (VCD) module was developed and evaluated as part of a Space Station Prototype (SSP) environmental control and life support system. The VCD module includes the waste tankage, pumps, post-treatment cells, automatic controls ...

P. P. Nuccio

1975-01-01

163

Compressive laser ranging.  

PubMed

Compressive sampling has been previously proposed as a technique for sampling radar returns and determining sparse range profiles with a reduced number of measurements compared to conventional techniques. By employing modulation on both transmission and reception, compressive sensing in ranging is extended to the direct measurement of range profiles without intermediate measurement of the return waveform. This compressive ranging approach enables the use of pseudorandom binary transmit waveforms and return modulation, along with low-bandwidth optical detectors to yield high-resolution ranging information. A proof-of-concept experiment is presented. With currently available compact, off-the-shelf electronics and photonics, such as high data rate binary pattern generators and high-bandwidth digital optical modulators, compressive laser ranging can readily achieve subcentimeter resolution in a compact, lightweight package. PMID:22179886

Babbitt, Wm Randall; Barber, Zeb W; Renner, Christoffer

2011-12-15

164

Compressible rotational deformation  

NASA Astrophysics Data System (ADS)

In recent years a number of studies have investigated the influence of compressibility on geophysical observables such as postglacial rebound deformation rates and the geoid. Some of these studies indicate that long-term signatures such as the geoid might be sensitive to compressibility. As both load relaxation and tidal-effective relaxation of the equatorial bulge are operative in a dependent way, polar wander can potentially be more sensitive to compressible rheologies if the interference between the two relaxation mechanisms is constructive. This has motivated us to study the influence of compressibility on true polar wander by means of spherical, laterally homogeneous, self-gravitating analytical earth models. As we wish to study both short-term rotational changes and polar wander on geological time-scales, we employ a Maxwell viscoelastic model instead of a Newtonian viscous model. The latter is commonly used in geoid modelling. The purpose of this paper is to concentrate on the basic physical aspects of the differences between compressible and incompressible rotational deformation, rather than applying the procedures to fine-graded multi-layered PREM models with realistic forcing functions. An important issue of our method concerns the analytical instead of numerical way of solving the differential equations by the propagator matrix method. Compressible viscoelastic relaxation has usually been treated numerically until now. The results show that homogeneous earth models do not have significant differences on long time-scales between compressible and the corresponding incompressible cases. Compressibility introduces a denumerably infinite set of short-time relaxation modes. The relaxation times of these dilatation modes can be approximated analytically. Two-layer core-mantle models show relatively large differences between incompressible and compressible Maxwell rheologies. Simplified models of true polar wander triggered by Heaviside loads show that differences of several tens of per cent between incompressible and compressible Maxwell rheologies are possible. True polar wander is decreased in the compressible case on both short and long time-scales, which means that smaller viscosities are required to explain polar-wander measurements than in the incompressible case.

Vermeersen, L. L. A.; Sabadini, R.; Spada, G.

1996-09-01

165

Changes in nerve function and nerve fibre structure induced by acute, graded compression.  

PubMed Central

Rabbit tibial nerves were subjected to direct, acute graded compression by means of an inflatable compression chamber. The acute and long term effects of 50, 200 and 400 mmHg applied for two hours on nerve function and nerve fibre structure were investigated. A pressure of 50 mmHg applied for two hours induced only minimal or no acute deterioration of maximal conduction velocity and nerve fibre structure. Conduction velocity was gradually reduced during compression at 200-400 mmHg pressure for two hours and in those cases the recovery of nerve conduction after pressure release was incomplete. Ultrastructural analysis revealed pronounced, early nerve fibre damage in these nerves. Three weeks after compression, nerves compressed at 50 mmHg for two hours had normal afferent and motor conduction velocity, although there were morphological signs of slight nerve fibre damage. Nerves compressed at 200 mmHg for two hours exhibited reduction of conduction velocity only at the level of compression, in contrast to the nerves compressed at 400 mmHg for two hours in which conduction velocity was reduced both at the level of compression and distal to the compressed segment. Morphologically, the nerves compressed at 200-400 mmHg for two hours showed varying degrees of demyelination and axonal degeneration three weeks after compression. Images

Rydevik, B; Nordborg, C

1980-01-01

166

Multispectral Image Compression Algorithms  

Microsoft Academic Search

This paper presents a data compression algorithm capable of significantly reducing the amounts of information contained in multispectral and hyperspectral images. The loss of information ranges from a perceptually lossless level, achieved at 20-30:1 compression ratios, to a one where exploitation of the images is still possible (over 100:1 ratios). A one-dimensional transform coder removes the spectral redundancy, and a

Tassos Markas; John H. Reif

1993-01-01

167

Smoothing DCT Compression Artifacts  

NASA Technical Reports Server (NTRS)

Image compression based on quantizing the image in the discrete cosine transform (DCT) domain can generate blocky artifacts in the output image. It is possible to reduce these artifacts and RMS error by adjusting measures of block edginess and image roughness, while restricting the DCT coefficient values to values that would have been quantized to those of the compressed image. We also introduce a DCT coefficient amplitude adjustment that reduces RMS error.

Ahumada, A. J., Jr.; Horng, R.; Statler, Irving C. (Technical Monitor)

1994-01-01

168

Vascular Arterial Compression Syndromes  

Microsoft Academic Search

Opinion statement  Vascular arterial compression syndromes are uncommon disorders due to dynamic anatomic compression of an artery resulting\\u000a in significant ischemia in the supplied territories with ensuing symptoms. The diagnosis of these disorders requires heightened\\u000a awareness and a high index of suspicion by the clinician. These diagnoses should be particularly suspected in young patients\\u000a with typical symptoms but without underlying cardiovascular

Veerendra Chadachan; Robert T. Eberhardt

2011-01-01

169

A compressive beamforming method  

Microsoft Academic Search

Compressive sensing (CS) is an emerging area which uses a relatively small number of non-traditional samples in the form of randomized projections to reconstruct sparse or compressible signals. This paper considers the direction-of-arrival (DOA) estimation problem with an array of sensors using CS. We show that by using random projections of the sensor data, along with a full waveform recording

Ali Cafer Gurbuz; James H. McClellan; Volkan Cevher

2008-01-01

170

Image compression technique  

DOEpatents

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.

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

1997-03-25

171

Intelligent bandwith compression  

NASA Astrophysics Data System (ADS)

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.

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

1980-02-01

172

Compressed Sensing in Astronomy  

NASA Astrophysics Data System (ADS)

Recent advances in signal processing have focused on the use of sparse representations in various applications. A new field of interest based on sparsity has recently emerged: compressed sensing. This theory is a new sampling framework that provides an alternative to the well-known Shannon sampling theory. In this paper, we investigate how compressed sensing (CS) can provide new insights into astronomical data compression. We first give a brief overview of the compressed sensing theory which provides very simple coding process with low computational cost, thus favoring its use for real-time applications often found onboard space mission. In practical situations, owing to particular observation strategies (for instance, raster scans) astronomical data are often redundant; in that context, we point out that a CS-based compression scheme is flexible enough to account for particular observational strategies. Indeed, we show also that CS provides a new fantastic way to handle multiple observations of the same field view, allowing us to recover low level details, which is impossible with standard compression methods. This kind of CS data fusion concept could lead to an elegant and effective way to solve the problem ESA is faced with, for the transmission to the earth of the data collected by PACS, one of the instruments onboard the Herschel spacecraft which will launched in late 2008/early 2009. We show that CS enables to recover data with a spatial resolution enhanced up to 30% with similar sensitivity compared to the averaging technique proposed by ESA.

Bobin, Jérôme; Starck, Jean-Luc; Ottensamer, Roland

2008-11-01

173

Alternative Compression Garments  

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

174

Image compression technique  

DOEpatents

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.

Fu, Chi-Yung (San Francisco, CA); Petrich, Loren I. (Livermore, CA)

1997-01-01

175

The Guardian's Science Weekly Podcast  

NSDL National Science Digital Library

Would you like to go around the world on a hunt for a lost rubber duck? How does learning about language sound? These are but a few of the topics covered in the Guardian's Science weekly podcast. Visitors will be delighted to learn that they can explore this vast buffet of science topics at their leisure. New visitors to the site can look through the Recent Shows area or move on down to the subject headings, which include climate change, energy, and space exploration. The site also features a lively blog that is updated frequently, and visitors are encouraged to leave comments. Some podcasts that shouldn't be missed are "The Joy of Science Demonstrations" and "The Festival of the Spoken Nerd." Also, visitors can learn more about the host of the program, the funny and interesting Alok Jha, by clicking on the link to his profile included in each podcast summary.

2012-04-27

176

Lossless compression of instrumentation data. Final report  

SciTech Connect

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.

Stearns, S.D.

1995-11-01

177

Compression-sensitive magnetic resonance elastography  

NASA Astrophysics Data System (ADS)

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.

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

2013-08-01

178

Cubital Tunnel External Compression Syndrome  

Microsoft Academic Search

External compression of the cubital tunnel comprises the acute and subacute forms of ulnar nerve compression at the elbow. Subacute compression is often seen in hospital practice and sometimes results in partial crippling of the hand. Prognosis for complete recovery is poor. Avoidance of a position of the elbow which predisposes to external compression of the ulnar nerve within the

Thomas G. Wadsworth; John R. Williams

1973-01-01

179

Lossy compression of noisy images  

Microsoft Academic Search

Noise degrades the performance of any image compression algorithm. This paper studies the effect of noise on lossy image compression. The effect of Gaussian, Poisson, and film-grain noise on compression is studied. To reduce the effect of the noise on compression, the distortion is measured with respect to the original image not to the input of the coder. Results of

Osama K. Al-shaykh; Russell M. Mersereau

1998-01-01

180

High-performance compression of astronomical images  

NASA Technical Reports Server (NTRS)

Astronomical images have some rather unusual characteristics that make many existing image compression techniques either ineffective or inapplicable. A typical image consists of a nearly flat background sprinkled with point sources and occasional extended sources. The images are often noisy, so that lossless compression does not work very well; furthermore, the images are usually subjected to stringent quantitative analysis, so any lossy compression method must be proven not to discard useful information, but must instead discard only the noise. Finally, the images can be extremely large. For example, the Space Telescope Science Institute has digitized photographic plates covering the entire sky, generating 1500 images each having 14000 x 14000 16-bit pixels. Several astronomical groups are now constructing cameras with mosaics of large CCD's (each 2048 x 2048 or larger); these instruments will be used in projects that generate data at a rate exceeding 100 MBytes every 5 minutes for many years. An effective technique for image compression may be based on the H-transform (Fritze et al. 1977). The method that we have developed can be used for either lossless or lossy compression. The digitized sky survey images can be compressed by at least a factor of 10 with no noticeable losses in the astrometric and photometric properties of the compressed images. The method has been designed to be computationally efficient: compression or decompression of a 512 x 512 image requires only 4 seconds on a Sun SPARCstation 1. The algorithm uses only integer arithmetic, so it is completely reversible in its lossless mode, and it could easily be implemented in hardware for space applications.

White, Richard L.

1993-01-01

181

Data compression of stereopairs  

NASA Technical Reports Server (NTRS)

This paper addresses the problem of stereopair data compression. Two fundamentally different techniques for compressing stereopairs are discussed. The first technique, called disparity-compensated transform-domain predictive coding, attempts to minimize the mean-square error between the original stereopair and the compressed stereopair. The second technique, called mixed-resolution coding, is a psychophysically justified technique that exploits known facts about human stereovision to code stereopairs in a subjectively acceptable manner. A method for assessing the quality of compressed stereopairs is also presented. It involves measuring the ability of an observer to perceive depth in coded stereopairs. It is found that observers generally perceived objects to be further away in compressed stereopairs than they did in originals. Finally, the problem of coding stereopairs is considered from a rate-distortion perspective. It is proved that the rate distortion limit for coding stereopairs cannot in general be achieved by a coder that first codes and decodes the right picture sequence independently of the left picture sequence, and then codes and decodes the left picture sequence given the decoded right picture sequence.

Perkins, Michael G.

1992-01-01

182

[Compression treatment after burns].  

PubMed

After healing up of the injury wounds, hypertrophic scars and keloids often develop, which are histologically characterised by irregulary arranged collagen fibre bundles and a strong vascularisation. Approximately 20 years ago, the so-called compression clothing, as for example suits, masks, gloves, stockings, were first employed for the prevention and therapy of these complications. These means of compressions are crosswise and lengthwise elastical and consist predominantly of elasthan and viscose. The pressure acting on the skin lies between 25 and 32 mmHg: thereby the values are above the average capillary pressure of 20 mmHg. The efficiency of the compression clothing after a burn injury is well proved by several studies, and one knows today that, for example in the case of children as from the 5th year of life, the results are better than in the case of adults from the 35th year of life. The compression effected at least during a period of 15 months slows down the blood circulation, reduces the number of capillaries and makes the scar become more pale. Furthermore, the orthologically parallel arranged collagen fibres maintain their arrangement due to the compression pressure and do not get irregularily arranged. PMID:10666821

Wienert, V

1999-01-01

183

[Radial nerve compression].  

PubMed

A new compression syndrome of the deep branch of the radial nerve is described, in which a sudden anterior displacement of a part of this nerve under maximal tension is followed by an axonotmesis. This happens in an area in which the deep branch of the radial nerve crossed some narrow structures which are unyielding and have more compression strength (tense cords of connective tissue Fig. 3). The operative finding of a torsion of the injured fascicles justifies the correctness of the immediate operative revision; otherwise the nerve regeneration would be impaired by the torted empty endoneural tubes. This description is a further constribution not observed before to the compression syndromes of the radial nerve, since in 1970 the author was able to give an explanation for the pathogenesis of compression palsies of the radial nerve, unclear up to that time but observed after forceful muscle contractions again and again since the beginning of this century. This observation gives the evidence that the occurrence of a peripheral compression lesion of nerves is not bound absolutely on the existence of a "physiological narrowness" (fibrous or osteofibrous tunnel etc.). This is also true for the median nerve. PMID:992486

Wilhelm, A

1976-01-01

184

A Block-sorting Lossless Data Compression Algorithm  

Microsoft Academic Search

We describe a block-sorting, lossless data compression algorithm, and our implementation of that algorithm. We compare the performance of our implementation with widely available data compressors running on the same hardware. The algorithm works by applying a reversible transformation to a block of input text. The transformation does not itself compress the data, but re-orders it to make it easy

M. Burrows; D. J. Wheeler

1994-01-01

185

A Rapid Compression Machine Modelling Study of the Heptane Isomers  

Microsoft Academic Search

Previously we have reported on the combustion behavior of all nine isomers of heptane in a rapid compression machine (RCM) with stoichiometric fuel and ''air'' mixtures at a compressed gas pressure of 15 atm. The dependence of autoignition delay times on molecular structure was illustrated. Here, we report some additional experimental work that was performed in order to address unusual

Emma J. Silke; Henry J. Curran; J M Simmie; William J. Pitz; Charles K. Westbrook

2005-01-01

186

Wavelet-based lossless compression scheme with progressive transmission capability  

Microsoft Academic Search

Lossless image compression with progressive transmis- sion capabilities plays a key role in measurement applications, requir- ing quantitative analysis and involving large sets of images. This work proposes a wavelet-based compression scheme that is able to op- erate in the lossless mode. The quantization module implements a new technique for the coding of the wavelet coefficients that is more effective

Adrian Munteanu; Jan Cornelis; Geert Van der Auwera; Paul Cristea

1999-01-01

187

Compressive Sensing of Time Series for Human Action Recognition  

Microsoft Academic Search

Compressive Sensing (CS) is an emerging signal processing technique where a sparse signal is reconstructed from a small set of random projections. In the recent literature, CS techniques have demonstrated promising results for signal compression and reconstruction. However, their potential as dimensionality reduction techniques for time series has not been significantly explored to date. To this aim, this work investigates

Oscar Perez Concha; Richard Yi Da Xu; Massimo Piccardi

2010-01-01

188

Distributed compressed sensing of Hyperspectral images via blind source separation  

Microsoft Academic Search

This paper describes a novel framework for compressive sampling (CS) of multichannel signals that are highly dependent across the channels. In this work, we assume few number of sources are generating the multichannel observations based on a linear mixture model. Moreover, sources are assumed to have sparse\\/compressible representations in some orthonormal basis. The main contribution of this paper lies in

Mohammad Golbabaee; Simon Arberet; Pierre Vandergheynst

2010-01-01

189

Micromechanics of Composite Laminate Compression Failures.  

National Technical Information Service (NTIS)

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...

E. G. Guynn W. L. Bradley

1988-01-01

190

Compressive strength of continuous fiber unidirectional composites  

NASA Astrophysics Data System (ADS)

Dow and Rosen's work in 1965 formed an intellectual framework for compressive strength of unidirectional composites. Compressive strength was explained in terms of micro-buckling, in which filaments are beams on an elastic foundation. They made simplifying assumptions, with a two dimensional idealization and linearized material properties. This study builds on their model, recognizing that the shear mode of instability drives unidirectional compressive strength. As a necessary corollary, the predictive methods developed in this study emphasize correct representation of composite shear stiffness. Non-linear effects related to matrix material properties, fiber misalignment, three dimensional representation, and thermal prestrains are taken into account. Four work streams comprise this study: first, development of a closed form analytical model; second, empirical methods development and model validation; third, creation and validation of a unit cell finite element model; and fourth, a patent application that leverages knowledge gained from the first three work streams. The analytical model characterizes the non-linearity of the matrix both with respect to shear and compressive loading. This improvement on existing analyses clearly shows why fiber modulus affects composite shear instability. Accounting for fiber misalignment in the model and experimental characterization of the fiber misalignment continuum are important contributions of this study. A simple method of compressive strength measurement of a small diameter monofilament glass-resin composite is developed. Sample definition and preparation are original, and necessary technologies are easily assessable to other researchers in this field. This study shows that glass fiber composites have the potential for high compressive strength. This potential is reached with excellent fiber alignment and suitable matrix characteristics, and results are consistent with model predictions. The unit cell three dimensional finite element model introduces a boundary condition that only allows compressive and shear deformation, thus recognizing the actual deformation mechanism of a compressed unidirectional composite. A new approach for representing the resin matrix is employed, giving improved correlation to empirical measurements noted in the literature. A method of accounting for realistic composite imperfections is introduced. The patent application work was fed by results from the first three areas. A new engineering structure is created in which buckling is beneficial. Post buckled behavior favorably affects other structural components in an overload situation. The first three work streams form a coherent unit and are mutually supportive. The analytical model predictions are corroborated by the experimental measurements. Finite element model predictions are consistent with the analytical model predictions.

Thompson, Ronald H.

191

A case of acute respiratory failure due to tracheal compression by a thyroid cyst.  

PubMed

A patient is described who presented with sudden collapse due to acute respiratory failure caused by tracheal compression from a thyroid cyst. He made a complete recovery and the cyst was electively excised two weeks later. PMID:8502979

Hinnie, J; Lafferty, M; Vasey, P; Milroy, R

1993-04-01

192

Isentropic Compression of Argon  

SciTech Connect

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.

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

193

Modelling of pressure-strain correlation in compressible turbulent flow  

NASA Astrophysics Data System (ADS)

Previous studies carried out in the early 1990s conjectured that the main compressible effects could be associated with the dilatational effects of velocity fluctuation. Later, it was shown that the main compressibility effect came from the reduced pressure-strain term due to reduced pressure fluctuations. Although better understanding of the compressible turbulence is generally achieved with the increased DNS and experimental research effort, there are still some discrepancies among these recent findings. Analysis of the DNS and experimental data suggests that some of the discrepancies are apparent if the compressible effect is related to the turbulent Mach number, M t . From the comparison of two classes of compressible flow, homogenous shear flow and inhomogeneous shear flow (mixing layer), we found that the effect of compressibility on both classes of shear flow can be characterized in three categories corresponding to three regions of turbulent Mach numbers: the low- M t , the moderate- M t and high- M t regions. In these three regions the effect of compressibility on the growth rate of the turbulent mixing layer thickness is rather different. A simple approach to the reduced pressure-strain effect may not necessarily reduce the mixing-layer growth rate, and may even cause an increase in the growth rate. The present work develops a new second-moment model for the compressible turbulence through the introduction of some blending functions of M t to account for the compressibility effects on the flow. The model has been successfully applied to the compressible mixing layers.

Huang, Siyuan; Fu, Song

2008-02-01

194

[Lossless compression of hyperspectral image for space-borne application].  

PubMed

In order to resolve the difficulty in hardware implementation, lower compression ratio and time consuming for the whole hyperspectral image lossless compression algorithm based on the prediction, transform, vector quantization and their combination, a hyperspectral image lossless compression algorithm for space-borne application was proposed in the present paper. Firstly, intra-band prediction is used only for the first image along the spectral line using a median predictor. And inter- band prediction is applied to other band images. A two-step and bidirectional prediction algorithm is proposed for the inter-band prediction. In the first step prediction, a bidirectional and second order predictor proposed is used to obtain a prediction reference value. And a improved LUT prediction algorithm proposed is used to obtain four values of LUT prediction. Then the final prediction is obtained through comparison between them and the prediction reference. Finally, the verification experiments for the compression algorithm proposed using compression system test equipment of XX-X space hyperspectral camera were carried out. The experiment results showed that compression system can be fast and stable work. The average compression ratio reached 3.05 bpp. Compared with traditional approaches, the proposed method could improve the average compression ratio by 0.14-2.94 bpp. They effectively improve the lossless compression ratio and solve the difficulty of hardware implementation of the whole wavelet-based compression scheme. PMID:23156795

Li, Jin; Jin, Long-xu; Li, Guo-ning

2012-08-01

195

Orbiting dynamic compression laboratory  

NASA Technical Reports Server (NTRS)

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.

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

1984-01-01

196

Compression by replication  

NASA Astrophysics Data System (ADS)

A recently introduced inference method based on system replication and an online message passing algorithm is employed to complete a previously suggested compression scheme based on a nonlinear perceptron. The algorithm is shown to approach the information theoretical bounds for compression as the number of replicated systems increases, offering superior performance compared to basic message passing algorithms. In addition, the suggested method does not require fine-tuning of parameters or other complementing heuristic techniques, such as the introduction of inertia terms, to improve convergence rates to nontrivial results.

Alamino, Roberto C.; Neirotti, Juan P.; Saad, David

2014-03-01

197

Compression by replication.  

PubMed

A recently introduced inference method based on system replication and an online message passing algorithm is employed to complete a previously suggested compression scheme based on a nonlinear perceptron. The algorithm is shown to approach the information theoretical bounds for compression as the number of replicated systems increases, offering superior performance compared to basic message passing algorithms. In addition, the suggested method does not require fine-tuning of parameters or other complementing heuristic techniques, such as the introduction of inertia terms, to improve convergence rates to nontrivial results. PMID:24730961

Alamino, Roberto C; Neirotti, Juan P; Saad, David

2014-03-01

198

Effect of State of Alertness on the Heart Rate Response to Ocular Compression in Human Infants  

Microsoft Academic Search

Because the state of alertness exerts a profound influence on autonomic cardiac control, we hypothesized, that the heart rate response to a vagal stimulus, i.e., ocular compression, may differ during different states of alertness. We studied 8 healthy infants with a postconceptional age of 35-41 weeks (mean ± SD 37.9 ± 2.1 weeks). They underwent a standardized ocular compression test

J. Rameta; B. Hausera; M. Dehanb; L. Curzi-Dascalovac; C. Gaultierc

1995-01-01

199

Preprototype Vapor Compression Distillation Subsystem development  

NASA Technical Reports Server (NTRS)

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.

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

1981-01-01

200

Envera Variable Compression Ratio Engine  

SciTech Connect

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 the compression ratio can be raised (to as much as 18:1) providing high engine efficiency. It is important to recognize that for a well designed VCR engine cylinder pressure does not need to be higher than found in current production turbocharged engines. As such, there is no need for a stronger crankcase, bearings and other load bearing parts within the VCR engine. The Envera VCR mechanism uses an eccentric carrier approach to adjust engine compression ratio. The crankshaft main bearings are mounted in this eccentric carrier or 'crankshaft cradle' and pivoting the eccentric carrier 30 degrees adjusts compression ratio from 9:1 to 18:1. The eccentric carrier is made up of a casting that provides rigid support for the main bearings, and removable upper bearing caps. Oil feed to the main bearings transits through the bearing cap fastener sockets. The eccentric carrier design was chosen for its low cost and rigid support of the main bearings. A control shaft and connecting links are used to pivot the eccentric carrier. The control shaft mechanism features compression ratio lock-up at minimum and maximum compression ratio settings. The control shaft method of pivoting the eccentric carrier was selected due to its lock-up capability. The control shaft can be rotated by a hydraulic actuator or an electric motor. The engine shown in Figures 3 and 4 has a hydraulic actuator that was developed under the current program. In-line 4-cylinder engines are significantly less expensive than V engines because an entire cylinder head can be eliminated. The cost savings from eliminating cylinders and an entire cylinder head will notably offset the added cost of the VCR and supercharging. Replacing V6 and V8 engines with in-line VCR 4-cylinder engines will provide high fuel economy at low cost. Numerous enabling technologies exist which have the potential to increase engine efficiency. The greatest efficiency gains are realized when the right combination of advanced and new technologies are packaged together to provide the greatest gains at the least cost. Aggressive engine downsiz

Charles Mendler

2011-03-15

201

78 FR 24321 - National Volunteer Week, 2013  

Federal Register 2010, 2011, 2012, 2013

...Number 79 (Wednesday, April 24, 2013)] [Presidential Documents...No. 79 / Wednesday, April 24, 2013 / Presidential Documents...19, 2013 National Volunteer Week, 2013 By the President of the...another. National Volunteer Week is a time to renew that...

2013-04-24

202

Data compression for sequencing data.  

PubMed

: Post-Sanger sequencing methods produce tons of data, and there is a general agreement that the challenge to store and process them must be addressed with data compression. In this review we first answer the question "why compression" in a quantitative manner. Then we also answer the questions "what" and "how", by sketching the fundamental compression ideas, describing the main sequencing data types and formats, and comparing the specialized compression algorithms and tools. Finally, we go back to the question "why compression" and give other, perhaps surprising answers, demonstrating the pervasiveness of data compression techniques in computational biology. PMID:24252160

Deorowicz, Sebastian; Grabowski, Szymon

2013-01-01

203

Compression failure of angle-ply laminates  

NASA Technical Reports Server (NTRS)

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 parameter, such as a ratio of wave amplitude to wave length, to describe waviness in a laminate would be inaccurate. Throughout, results for AS4/3502, studied previously, are included for comparison. At low off-axis angles, the AS4/3502 material system was found to be less sensitive to layer waviness than IM7/8551-7a. Analytical predictions were also obtained for laminates with waviness in only some of the layers. For this type of waviness, laminate compression strength could also be considered a function of which layers in the laminate were wavy, and where those wavy layers were. Overall, the geometrically nonlinear model correlates well with experimental results.

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

1991-01-01

204

Compression Tolerant Image Authentication  

Microsoft Academic Search

It is straightforward to apply general schemes forauthenticating digital data to the problem of authenticatingdigital images. However, such a scheme wouldnot authenticate images that have undergone lossycompression, even though they may not have been manipulatedotherwise. In this paper we propose a schemefor authenticating the visual content of digital images.This scheme is robust to compression noise, but willdetect deliberate manipulation of

Sushil K. Bhattacharjee; Martin Kutter

1998-01-01

205

Compressed web indexes  

Microsoft Academic Search

Web search engines use indexes to eciently retrieve pages containing specified query terms, as well as pages linking to specified pages. The problem of compressed indexes that permit such fast retrieval has a long history. We consider the problem: assuming that the terms in (or links to) a page are generated from a probability distribution, how well com- pactly can

Flavio Chierichetti; Ravi Kumar; Prabhakar Raghavan

2009-01-01

206

Compressibility of synthetic glaucophane  

NASA Astrophysics Data System (ADS)

The compressibilities of two synthetic glaucophane samples were measured over the range of 0-10 GPa at ambient temperature in a diamond-anvil cell at the Cornell High-Energy Synchrotron Source (CHESS). The pressure-volume data were fitted to the Birch-Murnaghan equation of state taking care to include only data with a minimum of deviatoric stress. When using a second-order truncation, both samples yielded essentially identical values of the bulk modulus K 0, which had an average value of 91.8 ± 1.3 GPa. Maximum compression was observed approximately along the a* axis as shown by the strain ellipsoid and supported by the a axis showing the highest compressibility. These results agree closely with the earlier study of a natural glaucophane single-crystal by Comodi et al. (Eur J Mineral 3:485-499, 1991), suggesting that the substitution of about 20-30 mol.% of Fe for Mg and Al in the structure may not significantly change its compressibility.

Jenkins, David M.; Corona, Juan Carlos; Bassett, William A.; Mibe, Kenji; Wang, Zhongwu

2010-04-01

207

Tension and Compression Activities  

NSDL National Science Digital Library

This page presents activities related to tension and compression from the Science & Engineering in the Lives of Students project. Activities include Bridge Building, Construction Beams, Hoover Dam Bypass, and Tug of War. Each activity includes a detailed description, list of the materials needed, science concepts covered, and reflection questions.

2013-07-17

208

Improved compression molding process  

NASA Technical Reports Server (NTRS)

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.

Heier, W. C.

1967-01-01

209

Compressive strength of flanges  

NASA Technical Reports Server (NTRS)

The maximum compressive stress carried by a hinged flange is computed from a deformation theory of plasticity combined with the theory for finite deflections for this structure. The computed stresses agree well with those found experimentally. Empirical observation indicates that the results will also apply fairly well to the more commonly used flanges which are not hinged.

Stowell, Elbridge Z

1951-01-01

210

Sampled Speech Compression System.  

National Technical Information Service (NTIS)

A sampled speech compression system, for two-dimensional processing of speech or other types of audio signal, comprises transmit/encode apparatus and receive/decode apparatus. The transmit/encode apparatus comprises means, adapted to receive an input sign...

H. J. Whitehouse J. M. Alsup

1979-01-01

211

Hyperspectral lossless compression  

NASA Astrophysics Data System (ADS)

Hyperspectral image data presents challenges to current transmission bandwidth and storage capabilities. To overcome these challenges and to retain the radiometric accuracy of the data, there is a need for good hyperspectral lossless compression. The current state-of-the-art lossless compression algorithm is JPEG-LS, which uses a 2-D edge-detecting predictor. Hyperspectral systems sample the electromagnetic spectrum very finely, which results in increased spectral correlation. A predictor that takes into account previous band information can obtain substantial gains in compression ratio. This paper discusses a number of different predictors that take advantage of the significant band-to-band (spectral) correlation within the hyperspectral imagery. A sample set of HYDICE, AVIRIS, and SEBASS imagery was used to evaluate the different predictors. While the JPEG-LS algorithm achieved just greater than 2:1 on most imagery, some of the 3-D prediction techniques achieved greater than 3:1 compression ratio. The characteristics of these test images and results from different predictors are presented in this paper.

Brower, Bernard V.; Lan, Austin; McCabe, Jill M.

1999-10-01

212

Compression of aerogels  

Microsoft Academic Search

When an aerogel is pressurized in a mercury porosimeter, the network is compressed, but no mercury enters the pores. Therefore, porosimetry cannot be used to measure the pore size distribution in an aerogel, but it does provide a measure of the bulk modulus of the network. For silica aerogels, the network is linearly elastic under small strains, then exhibits yield

George W. Scherer; Douglas M. Smith; Xiaomei Qiu; Julie M. Anderson

1995-01-01

213

Compressibility and Free Convection  

Microsoft Academic Search

The basic equations of laminar compressible flow and heat transfer are applied to the free convection boundary layer along an isothermal plate. Solutions which include the effect of all the parameters involved are given. It is found that in the complete approach, the profiles cannot be expressed in terms of one similarity variable and one parameter. The profiles, in dimensionless

S. Eshghy; F. A. Morrison Jr.

1966-01-01

214

Compress Your Files  

ERIC Educational Resources Information Center

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…

Branzburg, Jeffrey

2005-01-01

215

Hyperspectral Image Compression  

Microsoft Academic Search

Hyperspectral images gathered by satellites or aerial means provide a vast amount of data for geophysicists. A few applications include the exploration of minerals, research of land pollution, and military surveillance. NASA and other agencies are producing gigabytes of hyperspectral images which need to be transmitted and stored daily. As these images require high compression rates and preservation of data

Stephanie Wright; Jason Ashbach

2008-01-01

216

Listening and Compressed Speech.  

ERIC Educational Resources Information Center

Since listening plays such a large role in communication and learning, audio tapes can function in an important fashion in the design and delivery of instruction. In addition, recent research indicates that compressed audio tapes, in which speech is edited electronically by a sampling method so that the words-per-minute rate is increased without…

Arrasjid, Harun

217

Microseismic source imaging in a compressed domain  

NASA Astrophysics Data System (ADS)

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 compression rate that produces a tolerable amount of distortion into the results.

Vera Rodriguez, Ismael; Sacchi, Mauricio D.

2014-08-01

218

PDF approach for compressible turbulent reacting flows  

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

219

Four-Day Week Schedule. Research Brief  

ERIC Educational Resources Information Center

What does research say about the four-day week as an alternative school schedule? More than 100 districts in at least 12 states currently use a four-day week alternative schedule. Most are located in rural areas, serve less than 1000 students, and made the move to a shorter school week with longer instructional days for financial reasons. Although…

Marx, Gary E.

2007-01-01

220

Acceptance Test Report for 241-U compressed air system  

SciTech Connect

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.

Freeman, R.D.

1994-10-20

221

The New CCSDS Image Compression Recommendation  

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

222

Image and video compression for HDR content  

NASA Astrophysics Data System (ADS)

High Dynamic Range (HDR) technology can offer high levels of immersion with a dynamic range meeting and exceeding that of the Human Visual System (HVS). A primary drawback with HDR images and video is that memory and bandwidth requirements are significantly higher than for conventional images and video. Many bits can be wasted coding redundant imperceptible information. The challenge is therefore to develop means for efficiently compressing HDR imagery to a manageable bit rate without compromising perceptual quality. In this paper, we build on previous work of ours and propose a compression method for both HDR images and video, based on an HVS optimised wavelet subband weighting method. The method has been fully integrated into a JPEG 2000 codec for HDR image compression and implemented as a pre-processing step for HDR video coding (an H.264 codec is used as the host codec for video compression). Experimental results indicate that the proposed method outperforms previous approaches and operates in accordance with characteristics of the HVS, tested objectively using a HDR Visible Difference Predictor (VDP). Aiming to further improve the compression performance of our method, we additionally present the results of a psychophysical experiment, carried out with the aid of a high dynamic range display, to determine the difference in the noise visibility threshold between HDR and Standard Dynamic Range (SDR) luminance edge masking. Our findings show that noise has increased visibility on the bright side of a luminance edge. Masking is more consistent on the darker side of the edge.

Zhang, Yang; Reinhard, Erik; Agrafiotis, Dimitris; Bull, David R.

2012-10-01

223

Coded aperture compressive temporal imaging.  

PubMed

We use mechanical translation of a coded aperture for code division multiple access compression of video. We discuss the compressed video's temporal resolution and present experimental results for reconstructions of > 10 frames of temporal data per coded snapshot. PMID:23669910

Llull, Patrick; Liao, Xuejun; Yuan, Xin; Yang, Jianbo; Kittle, David; Carin, Lawrence; Sapiro, Guillermo; Brady, David J

2013-05-01

224

Compressibility Effects on the Growth and Structure of Homogeneous Turbulent Shear Flow  

NASA Technical Reports Server (NTRS)

Compressibility effects within decaying isotropic turbulence and homogeneous turbulent shear flow have been studied using direct numerical simulation. The objective of this work is to increase our understanding of compressible turbulence and to aid the development of turbulence models for compressible flows. The numerical simulations of compressible isotropic turbulence show that compressibility effects are highly dependent on the initial conditions. The shear flow simulations, on the other hand, show that measures of compressibility evolve to become independent of their initial values and are parameterized by the root mean square Mach number. The growth rate of the turbulence in compressible homogeneous shear flow is reduced compared to that in the incompressible case. The reduced growth rate is the result of an increase in the dissipation rate and energy transfer to internal energy by the pressure-dilatation correlation. Examination of the structure of compressible homogeneous shear flow reveals the presence of eddy shocklets, which are important for the increased dissipation rate of compressible turbulence.

Blaisdell, G. A.; Mansour, N. N.; Reynolds, W. C.

1993-01-01

225

A classification of compression methods and their usefulness for a large data processing center  

Microsoft Academic Search

The compression techniques surveyed in this paper all work to reduce storage space for data files at the price of increased CPU activity needed for compression and decompression. As CPU time becomes cheaper relative to the cost of external storage devices, compression appears as an increasingly attractive option for dealing with large files.

D. Gotlieb; Steven A. Hagerth; Philippe G. H. Lehot; Henry S. Rabinowitz

1975-01-01

226

Compressed-Domain Video Indexing Techniques Using DCT and Motion Vector Information in MPEG Video  

Microsoft Academic Search

Development of various multimedia applications hinges on the availability of fast and efficient storage, browsing,indexing, and retrieval techniques. Given that video is typically stored efficiently in a compressed format, ifwe can analyze the compressed representation directly, we can avoid the costly overhead of decompressing andoperating at the pixel level. Compressed domain parsing of video has been presented in earlier work

Vikrant Kobla; David S. Doermann; King-Ip Lin; Christos Faloutsos

1997-01-01

227

Multimode Data-Compression System  

NASA Technical Reports Server (NTRS)

Data-compression system developed to satisfy need for high-speed, high-performance compression of data from sources as diverse as medical images, high-definition television images, audio signals, readouts from scientific instruments, and binary data files. Maximum data-transmission capability of communication channel or storage capacity of storage device multiplied by approximately compression ratio. Various combinations of lossless and lossy compression chosen to suit various data streams.

Fang, Wai-Chi

1996-01-01

228

Predictive Encoding in Text Compression.  

ERIC Educational Resources Information Center

Presents three text compression methods of increasing power and evaluates each based on the trade-off between compression gain and processing time. The advantages of using hash coding for speed and optimal arithmetic coding to successor information for compression gain are discussed. (26 references) (Author/CLB)

Raita, Timo; Teuhola, Jukka

1989-01-01

229

Compression of Embedded System Programs  

Microsoft Academic Search

Embedded systems are often sensitive to space, weight, and cost considerations. Reducing the size of stored programs can significantly improve these factors. This paper discusses a program compression methodology based on existing processor architectures. The authors examine practical and theoretical measures for the maximum compression rate of a suite of programs across six modern architectures. The theoretical compression rate is

Michael Kozuch; Andrew Wolfe

1994-01-01

230

Compression behavior of nanocrystalline forsterite  

NASA Astrophysics Data System (ADS)

Compression behavior of Nanocrystalline Forsterite is studied with the help of equation of state. The pressure dependence of volume compression of nano and macrocrystalline Forsterite, have been analyzed using Usual Taits Equation of State (UTE). It is found here that nano forsterite is more compressible than bulk Forsterite. This theory also reveals that Usual Taits Equation of State is equally valid for nanomaterials also.

Chandra, Jeewan; Kholiya, Kuldeep

2013-06-01

231

Data Compression and Harmonic Analysis  

Microsoft Academic Search

In this paper we review some recent interactions between harmonic analysis and data compression. The story goes back of course to Shannon's theory in the case of Gaussian stationary processes, which says that transforming into a Fourier basis followed by block coding gives an optimal lossy compression technique; practical developments like transform- based image compression have been inspired by this

David L. Donoho; Martin Vetterli; Ronald A. Devore; Ingrid Daubechies

1998-01-01

232

Weekly Milk Prediction on Dairy Goats using Neural Networks  

Microsoft Academic Search

Artificial neural networks (NN) have been widely used for both prediction and classification tasks in many fields of knowledge, however, few studies are available on dairy science. In this work we use NN models to predict next week goat milk based on actual and previous milk production. A total of 35 Murciano-Granadina dairy goats were selected from a commercial farm

C. Fernández; E. Soria; P. Sánchez-Seiquer; L. Gómez-Chova; R. Magdalena; J. D. Martín; M. J. Navarro; A. J. Serrano

233

Weekly milk prediction on dairy goats using neural networks  

Microsoft Academic Search

Abstract Artificial neural networks ,(NN) have ,been widely ,used for both prediction and classification tasks in many fields of knowledge, however, few studies are available on dairy science. In this work we use,NN models to predict next week goat milk based on actual and previous milk production. A total of 35 Murciano-Granadina dairy ,goats were selected from a commercial farm

C. Fernández; Emilio Soria-olivas; P. Sánchez-seiquer; Luis Gómez-chova; R. Magdalena; José David Martín-guerrero; M. J. Navarro; Antonio J. Serrano-lópez

2007-01-01

234

Shock compression of geological materials  

NASA Astrophysics Data System (ADS)

Understanding the shock compression of geological materials is important for many applications, and is particularly important to the mining industry. During blast mining the response to shock loading determines the wave propagation speed and resulting fragmentation of the rock. The present work has studied the Hugoniot of two geological materials; Lake Quarry Granite and Gosford Sandstone. For samples of these materials, the composition was characterised in detail. The Hugoniot of Lake Quarry Granite was predicted from this information as the material is fully dense and was found to be in good agreement with the measured Hugoniot. Gosford Sandstone is porous and undergoes compaction during shock loading. Such behaviour is similar to other granular material and we show how it can be described using a P-a compaction model.

Kirk, S.; Braithwaite, C.; Williamson, D.; Jardine, A.

2014-05-01

235

Multicomponent compression with the latest CCSDS recommendation  

NASA Astrophysics Data System (ADS)

For optimum compression performances of multispectral and hyperspectral images, algorithms must exploit both spectral and spatial correlation of the data. To do this, different approaches are possible: a spectral decorrelation preprocessing stage followed by application of an image compressor to the decorrelated bands or, an integrated solution dealing with the three dimensions simultaneously. For example, Part II of JPEG2000 standard introduces a multi-component transform capability applied prior Part I spatial wavelet decomposition and coding. This article proposes to use the CCSDS Image Data Compression Recommendation together with a spectral transform to perform a multicomponent compression. Depending on the number of spectral bands, an efficient spectral transform, such as the DCT, is applied first and the CCSDS algorithm encodes each decorrelated bands. We compare the performances of such a scheme with JPEG2000 and also with a comparable scheme with a very simple decorrelation stage. Thanks to a bit plane coding of blocks of wavelet coefficients, the CCSDS encoder is a good tool to control the quality or the rate of these transformed bands. We present performances for different types of sensors: multispectral and hyperspectral. This work is part of the CNES contribution to the new CCSDS Multispectral and Hyperspectral Data Compression Working Group.

Thiebaut, Carole; Camarero, Roberto

2009-08-01

236

Aerosol and cloud relations and weekly cycles over Central Europe  

NASA Astrophysics Data System (ADS)

In this work, the aerosol and cloud relationships and weekly cycle patterns over Central Europe are examined using level-2 aerosol data from the TERRA MODIS satellite instrument to compile a decadal (2000-2010) 0.1 x 0.1 degree resolution gridded dataset as well as and total cloud cover (TCC) TERRA MODIS data and coarser resolution ISCCP TCC data. Aerosols and TCC were found to be positively correlated for all seasons, the slope of the correlation being slightly higher for low AOD values. A co-examination of AOD, TCC and NCAR/NCEP sea level pressure shows that the positive AOD-TCC correlation holds separately in all pressure bins, thus indicating that the correlation is not a synoptic artefact. A study of the weekly cycle of AOD shows that the main part of the positive (i.e. with midweek peak) weekly cycle plume extends over the central part of Central Europe, with the weekly cycle index (WCI) levels gradually decreasing until the weekly cycle becomes negative (i.e. with weekend peak) when moving away. No clear connection between the WCI patterns and topography was found while there is an apparent correlation between positive weekly cycles in summer and population density. A clear Monday minimum appears over regions with high positive WCI. Monday shifts to Tuesday when moving to the East, indicating aerosol transport from the dominating westerly wind flow. The WCI values and the average percent departures (APDs) for the day of weekly maximum and minimum were examined for 22 selected stations from previous ground-based weekly cycle studies. The weekly cycle is positive and statistically significant for only a few stations situated in France, Germany, Czech Republic and Belgium. A comparison with 1 x 1 degree level-3 MODIS TERRA data shows that in most cases level-3 data can give an indication of the local aerosol weekly cycle strength and phase. The satellite derived day of the weekly maximum and minimum is, generally, in line with results from ground-based studies. The seasonal examination of the WCI patterns show that the positive signal over Central Europe is strongest during summer. More interestingly, the amplitude and phasing of the AOD weekly variability agrees with the TCC one, both for MODIS and ISCCP.

Kourtidis, K.; Georgoulias, A.; Alexandri, G.

2012-04-01

237

Kronecker compressive sensing.  

PubMed

Compressive sensing (CS) is an emerging approach for the acquisition of signals having a sparse or compressible representation in some basis. While the CS literature has mostly focused on problems involving 1-D signals and 2-D images, many important applications involve multidimensional signals; the construction of sparsifying bases and measurement systems for such signals is complicated by their higher dimensionality. In this paper, we propose the use of Kronecker product matrices in CS for two purposes. First, such matrices can act as sparsifying bases that jointly model the structure present in all of the signal dimensions. Second, such matrices can represent the measurement protocols used in distributed settings. Our formulation enables the derivation of analytical bounds for the sparse approximation of multidimensional signals and CS recovery performance, as well as a means of evaluating novel distributed measurement schemes. PMID:21859622

Duarte, Marco F; Baraniuk, Richard G

2012-02-01

238

Compression and entrapment neuropathies.  

PubMed

Peripheral nerve entrapments are frequent. They usually appear in anatomical tunnels such as the carpal tunnel. Nerve compressions may be due to external pressure such as the fibular nerve at the fibular head. Malignant or benign tumors may also damage the nerve. For each nerve from the upper and lower limbs, detailed clinical, electrophysiological, imaging, and therapeutic aspects are described. In the upper limbs, carpal tunnel syndrome and ulnar neuropathy at the elbow are the most frequent manifestations; the radial nerve is less frequently involved. Other nerves may occasionally be damaged and these are described also. In the lower limbs, the fibular nerve is most frequently involved, usually at the fibular head by external compression. Other nerves may also be involved and are therefore described. The clinical and electrophysiological examination are very important for the diagnosis, but imaging is also of great use. Treatments available for each nerve disease are discussed. PMID:23931789

Bouche, P

2013-01-01

239

Compressive Sensing DNA Microarrays  

PubMed Central

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.

2009-01-01

240

Compressive optical MONTAGE photography  

NASA Astrophysics Data System (ADS)

The Compressive Optical MONTAGE Photography Initiative (COMP-I) is an initiative under DARPA's MONTAGE program. The goals of COMP-I are to produce 1 mm thick visible imaging systems and 5 mm thick IR systems without compromising pixel-limited resolution. Innovations of COMP-I include focal-plane coding, block-wise focal plane codes, birefringent, holographic and 3D optical elements for focal plane remapping and embedded algorithms for image formation. In addition to meeting MONTAGE specifications for sensor thickness, focal plane coding enables a reduction in the transverse aperture size, physical layer compression of multispectral and hyperspectral data cubes, joint optical and electronic optimization for 3D sensing, tracking, feature-specific imaging and conformal array deployment.

Brady, David J.; Feldman, Michael; Pitsianis, Nikos; Guo, J. P.; Portnoy, Andrew; Fiddy, Michael

2005-08-01

241

Malignant spinal cord compression  

Microsoft Academic Search

Opinion statement  Malignant spinal cord compression is one of the most dreaded complications of cancer. If untreated, it can lead to worsening\\u000a neurologic function culminating in paralysis and sphincter incontinence. The most challenging aspect in the management of\\u000a this complication is early diagnosis because the single most important factor determining outcome is the level of neurologic\\u000a function at initiation of therapy.

Madhuri Yalamanchili; Glenn J. Lesser

2003-01-01

242

High-Dynamic-Range Texture Compression for Rendering Systems of Different Capacities  

Microsoft Academic Search

In this paper, we propose a novel approach for high-dynamic-range (HDR) texture compression (TC) suitable for rendering systems of different capacities. Based on the previously proposed DHTC scheme, we first work out an improved joint-channel compression framework, which is robust and flexible enough to provide compressed HDR textures at different bit rates. Then, two compressed HDR texture formats based on

Wen Sun; Yan Lu; Feng Wu; Shipeng Li; John Tardif

2010-01-01

243

Shock temperature measurements of pre-compressed water using two-color streaked optical pyrometer  

Microsoft Academic Search

A coupling method of static pre-compression and laser-shock compression has been used to investigate off-Hugoniot states such as internal conditions of planets. This method has a possibility to generate lower temperature conditions than principal Hugoniot. In this work, shock temperature of a pre-compressed water has been experimentally obtained. We measured two-color emission from a shock wave driven into the pre-compressed

Tomoaki Kimura; Norimasa Ozaki; Tomoyuki Terai; Tomokazu Sano; Kohei Miyanishi; Takashi Endo; Tatsuya Jitsui; Akio Hirose; Tomoyuki Kakeshita; Ryosuke Kodama; Takuo Okuchi; Katsuya Shimizu; Takayoshi Sano; Youichi Sakawa; Masahiro Ikoma

2009-01-01

244

Compression of Semesters or Intensity of Study: What is it that Increases Student Success?  

ERIC Educational Resources Information Center

This study examined the relationship between intensity of study (defined as more hours per week of class within a subject matter area) and student success. The researcher identified two possible methods for increasing the intensity of study: (1) Compression Hypothesis--shortening the length of terms and increasing the amount of time per week spent…

Spurling, Steven

245

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

ERIC Educational Resources Information Center

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…

Hyun, Eunsook; Kretovics, Mark; Crowe, Alicia

2006-01-01

246

Compressibility of titanosilicate melts  

NASA Astrophysics Data System (ADS)

The effect of composition on the relaxed adiabatic bulk modulus (K0) of a range of alkali- and alkaline earth-titanosilicate [X{2/n/n+}TiSiO5 (X=Li, Na, K, Rb, Cs, Ca, Sr, Ba)] melts has been investigated. The relaxed bulk moduli of these melts have been measured using ultrasonic interferometric methods at frequencies of 3, 5 and 7 MHz in the temperature range of 950 to 1600°C (0.02 Pa s < ?s < 5 Pa s). The bulk moduli of these melts decrease with increasing cation size from Li to Cs and Ca to Ba, and with increasing temperature. The bulk moduli of the Li-, Na-, Ca- and Ba-bearing metasilicate melts decrease with the addition of both TiO2 and SiO2 whereas those of the K-, Rb- and Cs-bearing melts increase. Linear fits to the bulk modulus versus volume fraction of TiO2 do not converge to a common compressibility of the TiO2 component, indicating that the structural role of TiO2 in these melts is dependent on the identity of the cation. This proposition is supported by a number of other property data for these and related melt compositions including heat capacity and density, as well as structural inferences from X-ray absorption spectroscopy (XANES). The compositional dependence of the compressibility of the TiO2 component in these melts explains the difficulty incurred in previous attempts to incorporate TiO2 in calculation schemes for melt compressibility. The empirical relationship K?V-4/3 for isostructural materials has been used to evaluate the compressibility-related structural changes occurring in these melts. The alkali metasilicate and disilicate melts are isostructural, independent of the cation. The addition of Ti to the metasilicate composition (i.e. X2TiSiO5), however, results in a series of melts which are not isostructural. The alkaline-earth metasilicate and disilicate compositions are not isostructural, but the addition of Ti to the metasilicate compositions (i.e. XTiSiO5) would appear, on the basis of modulus-volume systematics, to result in the melts becoming isostructural with respect to compressibility.

Webb, Sharon L.; Dingwell, Donald B.

1994-06-01

247

Solar Week Monday: Play the Game  

NSDL National Science Digital Library

This is a game associated with activities during Solar Week, a twice-yearly event in March and October during which classrooms are able to interact with scientists studying the Sun. Outside of Solar Week, information, activities, and resources are archived and available online at any time. During this game, learners use clues to find out the color, average size, temperature, and location of the Sun. This activity is scheduled to occur during Monday of Solar Week.

248

Solar Week Friday: Learn about Solar Careers  

NSDL National Science Digital Library

This is a reading associated with activities during Solar Week, a twice-yearly event in March and October during which classrooms are able to interact with scientists studying the Sun. Outside of Solar Week, information, activities, and resources are archived and available online at any time. This is a set of biographical readings by which learners can find out more about female solar scientists. This reading activity is scheduled to occur during Friday of Solar Week.

249

Solar Week Friday: Research Jobs & Salaries  

NSDL National Science Digital Library

This is a reading and research activity associated with activities during Solar Week, a twice-yearly event in March and October during which classrooms are able to interact with scientists studying the Sun. Outside of Solar Week, information, activities, and resources are archived and available online at any time. During this activity, learners research different science jobs and salary ranges in several online employment databases and answer related questions. This activity is scheduled to occur during Friday of Solar Week.

250

Compression of Martian atmosphere for production of oxygen  

NASA Technical Reports Server (NTRS)

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.

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

1991-01-01

251

Compressive failure due to kinking of fibrous composites  

NASA Astrophysics Data System (ADS)

A new approach to compressive strength modeling of fibrous composites, that bridges the micromechanics relevant to compressive failure due to fiber kinking with the global characteristics of a composite structure, is presented in this work. To analyze the mechanics of kinking and calculate the critical compressive stress, a steady state kink propagation model is utilized for the layers under compression in the fiber direction. The proposed model incorporates the influence of boundary conditions, laminate thickness and lay-up configuration, as well as the importance of the micro-geometry. The analysis results are used to gain a better understanding of the influence of the macro-geometry in addition to the micro-geometry and fiber and matrix material properties. The predictions of the model for unidirectional laminates under direct compression and cross-ply laminates under four-point bending are discussed and comparisons with some experimental results for carbon/thermoplastic composites are presented.

Lagoudas, Dimitris C.; Saleh, Ahmed M.

252

Watermarking scheme for authentication of compressed image  

NASA Astrophysics Data System (ADS)

As images are commonly transmitted or stored in compressed form such as JPEG, to extend the applicability of our previous work, a new scheme for embedding watermark in compressed domain without resorting to cryptography is proposed. In this work, a target image is first DCT transformed and quantised. Then, all the coefficients are implicitly watermarked in order to minimize the risk of being attacked on the unwatermarked coefficients. The watermarking is done through registering/blending the zero-valued coefficients with a binary sequence to create the watermark and involving the unembedded coefficients during the process of embedding the selected coefficients. The second-order neighbors and the block itself are considered in the process of the watermark embedding in order to thwart different attacks such as cover-up, vector quantisation, and transplantation. The experiments demonstrate the capability of the proposed scheme in thwarting local tampering, geometric transformation such as cropping, and common signal operations such as lowpass filtering.

Hsieh, Tsung-Han; Li, Chang-Tsun; Wang, Shuo

2003-11-01

253

Turbulence modeling for high speed compressible flows  

NASA Technical Reports Server (NTRS)

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.

Chandra, Suresh

1993-01-01

254

Ischemic Compression After Trigger Point Injection Affect the Treatment of Myofascial Trigger Points  

PubMed Central

Objective To investigate the effects of trigger point injection with or without ischemic compression in treatment of myofascial trigger points in the upper trapezius muscle. Methods Sixty patients with active myofascial trigger points in upper trapezius muscle were randomly divided into three groups: group 1 (n=20) received only trigger point injections, group 2 (n=20) received trigger point injections with 30 seconds of ischemic compression, and group 3 (n=20) received trigger point injections with 60 seconds of ischemic compression. The visual analogue scale, pressure pain threshold, and range of motion of the neck were assessed before treatment, immediately after treatment, and 1 week after treatment. Korean Neck Disability Indexes were assessed before treatment and 1 week after treatment. Results We found a significant improvement in all assessment parameters (p<0.05) in all groups. But, receiving trigger point injections with ischemic compression group showed significant improvement as compared with the receiving only trigger point injections group. And no significant differences between receiving 30 seconds of ischemic compression group and 60 seconds of ischemic compression group. Conclusion This study demonstrated the effectiveness of ischemic compression for myofascial trigger point. Trigger point injections combined with ischemic compression shows better effects on treatment of myofascial trigger points in the upper trapezius muscle than the only trigger point injections therapy. But the duration of ischemic compression did not affect treatment of myofascial trigger point.

Kim, Soo A; Oh, Ki Young; Choi, Won Hyuck

2013-01-01

255

CMHOG: Code for Ideal Compressible Hydrodynamics  

NASA Astrophysics Data System (ADS)

CMHOG (Connection Machine Higher Order Godunov) is a code for ideal compressible hydrodynamics based on the Lagrange-plus-remap version of the piecewise parabolic method (PPM) of Colella & Woodward (1984, J. Comp. Phys., 74, 1). It works in one-, two- or three-dimensional Cartesian coordinates with either an adiabatic or isothermal equation of state. A limited amount of extra physics has been added using operator splitting, including optically-thin radiative cooling, and chemistry for combustion simulations.

Piner, B. Glenn; Stone, James M.; Teuben, Peter J.

2011-01-01

256

Comparative data compression techniques and multi-compression results  

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

257

On Compressibility and Acceleration of Orthogonal NMF for POMDP Compression  

NASA Astrophysics Data System (ADS)

State space compression is one of the recently proposed approaches for improving POMDP’s tractability. Despite its initial success, it still carries two intrinsic limitations. First, not all POMDP problems can be compressed equally well. Also, the cost of computing the compressed space itself may become significant as the size of the problem is scaled up. In this paper, we address the two issues with respect to an orthogonal non-negative matrix factorization recently proposed for POMDP compression. In particular, we first propose an eigenvalue analysis to evaluate the compressibility of a POMDP and determine an effective range for the dimension reduction. Also, we incorporate the interior-point gradient acceleration into the orthogonal NMF and derive an accelerated version to minimize the compression overhead. The validity of the eigenvalue analysis has been evaluated empirically. Also, the proposed accelerated orthogonal NMF has been demonstrated to be effective in speeding up the policy computation for a set of robot navigation related problems.

Li, Xin; Cheung, William K.; Liu, Jiming

258

New Regenerative Cycle for Vapor Compression Refrigeration  

SciTech Connect

The main objective of this project is to confirm on a well-instrumented prototype the theoretically derived claims of higher efficiency and coefficient of performance for geothermal heat pumps based on a new regenerative thermodynamic cycle as comparing to existing technology. In order to demonstrate the improved performance of the prototype, it will be compared to published parameters of commercially available geothermal heat pumps manufactured by US and foreign companies. Other objectives are to optimize the design parameters and to determine the economic viability of the new technology. Background (as stated in the proposal): The proposed technology closely relates to EERE mission by improving energy efficiency, bringing clean, reliable and affordable heating and cooling to the residential and commercial buildings and reducing greenhouse gases emission. It can provide the same amount of heating and cooling with considerably less use of electrical energy and consequently has a potential of reducing our nations dependence on foreign oil. The theoretical basis for the proposed thermodynamic cycle was previously developed and was originally called a dynamic equilibrium method. This theory considers the dynamic equations of state of the working fluid and proposes the methods for modification of T-S trajectories of adiabatic transformation by changing dynamic properties of gas, such as flow rate, speed and acceleration. The substance of this proposal is a thermodynamic cycle characterized by the regenerative use of the potential energy of two-phase flow expansion, which in traditional systems is lost in expansion valves. The essential new features of the process are: (1) The application of two-step throttling of the working fluid and two-step compression of its vapor phase. (2) Use of a compressor as the initial step compression and a jet device as a second step, where throttling and compression are combined. (3) Controlled ratio of a working fluid at the first and second step of compression. In the proposed system, the compressor compresses the vapor only to 50-60% of the final pressure, while the additional compression is provided by a jet device using internal potential energy of the working fluid flow. Therefore, the amount of mechanical energy required by a compressor is significantly reduced, resulting in the increase of efficiency (either COP or EER). The novelty of the cycle is in the equipment and in the way the multi-staging is accomplished. The anticipated result will be a new refrigeration system that requires less energy to accomplish a cooling task. The application of this technology will be for more efficient designs of: (1) Industrial chillers, (2) Refrigeration plants, (3) Heat pumps, (4) Gas Liquefaction plants, (5) Cryogenic systems.

Mark J. Bergander

2005-08-29

259

The quest for 'diagnostically lossless' medical image compression: a comparative study of objective quality metrics for compressed medical images  

NASA Astrophysics Data System (ADS)

Our study, involving a collaboration with radiologists (DK,NSK) as well as a leading international developer of medical imaging software (AGFA), is primarily concerned with improved methods of assessing the diagnostic quality of compressed medical images and the investigation of compression artifacts resulting from JPEG and JPEG2000. In this work, we compare the performances of the Structural Similarity quality measure (SSIM), MSE/PSNR, compression ratio CR and JPEG quality factor Q, based on experimental data collected in two experiments involving radiologists. An ROC and Kolmogorov-Smirnov analysis indicates that compression ratio is not always a good indicator of visual quality. Moreover, SSIM demonstrates the best performance, i.e., it provides the closest match to the radiologists' assessments. We also show that a weighted Youden index1 and curve tting method can provide SSIM and MSE thresholds for acceptable compression ratios.

Kowalik-Urbaniak, Ilona; Brunet, Dominique; Wang, Jiheng; Koff, David; Smolarski-Koff, Nadine; Vrscay, Edward R.; Wallace, Bill; Wang, Zhou

2014-03-01

260

Construction of an ultra low temperature cryostat and transverse acoustic spectroscopy in superfluid helium-3 in compressed aerogels  

NASA Astrophysics Data System (ADS)

An ultra low temperature cryostat is designed and implemented in this work to perform experiments at sub-millikelvin temperatures, specifically aimed at understanding the superfluid phases of 3He in various scenarios. The cryostat is a combination of a dilution refrigerator (Oxford Kelvinox 400) with a base temperature of 5.2 mK and a 48 mole copper block as the adiabatic nuclear demagnetization stage with a lowest temperature of ? 200 muK. With the various techniques implemented for limiting the ambient heat leak to the cryostat, we were able to stay below 1 mK for longer than 5 weeks. The details of design, construction and performance of the cryostat are presented. We measured high frequency shear acoustic impedance in superfluid 3He in 98% porosity aerogel at pressures of 29 bar and 32 bar in magnetic fields upto 3 kG with the aerogel cylinder compressed along the symmetry axis to generate global anisotropy. With 5% compression, there is an indication of a supercooled A-like to B-like transition in aerogel in a wider temperature width than the A phase in the bulk, while at 10% axial compression, the A-like to B-like transition is absent on cooling down to ? 300 muK in zero magnetic field and in magnetic fields up to 3 kG. This behavior is in contrast to that in 3He in uncompressed aerogels, in which the supercooled A-like to B-like transitions have been identified by various experimental techniques. Our result is consistent with theoretical predictions. To characterize the anisotropy in compressed aerogels, optical birefringence is measured in 98% porosity silica aerogel samples subjected to various degrees of uniaxial compression up to 15% strain, with wavelengths between 200 to 800 nm. Uncompressed aerogels exhibit no or a minimal degree of birefringence, indicating the isotropic nature of the material over the length scale of the wavelength. Uniaxial compression of aerogel introduces global anisotropy, which produces birefringence in the material. We observed a quasi-linear strain dependence in Deltan = ne -- no in compressed aerogels, where n e(o) is the index of refraction for the extraordinary (ordinary) ray of light that has its polarization parallel to the compression axis. Incidentally, this effect has potential applications for aerogels as tunable waveplates operating in a broad spectral range.

Bhupathi, Pradeep

261

Enhanced p62 expression triggers concomitant autophagy and apoptosis in a rat chronic spinal cord compression model.  

PubMed

Chronic spinal cord compression is the result of mechanical pressure on the spinal cord, which in contrast to traumatic spinal cord injury, leads to slowly progressing nerve degeneration. These two types of spinal cord injuries may trigger similar mechanisms, including motoric nerve cell apoptosis and autophagy, however, depending on differences in the underlying injury severity, nerve reactions may predominantly involve the conservation of function or the initiation of functions for the removal of irreversibly damaged cells. p62 is a multidomain adapter protein, which is involved in apoptosis and cell survival as well as autophagy, and is a common component of protein aggregations in neurodegenerative diseases. In the present study, a rat chronic spinal cord compression model was used, in which the spinal cord was progressively compressed for six weeks and then constantly compressed for another 10 weeks. As a result Basso, Beattie and Bresnahan locomotor scaling revealed a gradual score decrease until the 6th week followed by constant recovery until the 16th week after spinal cord compression was initiated. During the first eight weeks of the experiment, p62 and nuclear factor??B (NF??B) were increasingly expressed up to a constant plateau at 12?16 weeks, whereas caspase 3 exhibited a marginally enhanced expression at 8 weeks, however, reached a constant maximum peak 12?16 weeks after the beginning of spinal cord compression. It was hypothesized that, in the initial phase of spinal cord compression, enhanced p62 expression triggered NF??B activity, directing the cell responses mainly to cell survival and autophagy, whereas following eight weeks of spinal cord compression, caspase 3 was additionally activated indicating cumulative elimination of irreversibly damaged nerve cells with highly activated autophagy. PMID:24715058

Chen, Zhi; Fu, Qingge; Shen, Baoliang; Huang, Xuan; Wang, Kun; He, Ping; Li, Fengning; Zhang, Fan; Shen, Hongxing

2014-06-01

262

Image Compression Devices  

NASA Technical Reports Server (NTRS)

The Rice algorithm is a "lossless" compression algorithm; it takes an image or other data that has been broken down into short strings of digital data, then processes each string mathematically to reduce the amount of memory required to store or transmit them. It is particularly useful in medical, scientific or engineering applications where all data must be preserved. Originally developed at Jet Propulsion Laboratory, the technology is marketed by Advanced Hardware Architectures, a company started by a former employee of the NASA Microelectronics Research Center.

1994-01-01

263

Compression ignition fuel compositions  

SciTech Connect

Coking in and around the injector nozzle of indirect injection compression ignition engines is reduced by means of distillate fuel with which has been blended suitable concentrations of organic nitrate ignition accelerator, copolymer of an alpha-olefin having from 8 to 30 carbon and an N-substituted maleimide wherein the N-substituents are organic radicals having from 3 to 60 carbons and from 1 to 5 amine nitrogens, said copolymer having from 4 to 20 repeating olefin-maleimide units, and hydrocarbyl amine having from 3 to 60 carbons and from 1 to 10 nitrogens.

Hanlon, J. V.

1984-11-13

264

Beamforming using compressive sensing.  

PubMed

Compressive sensing (CS) is compared with conventional beamforming using horizontal beamforming of at-sea, towed-array data. They are compared qualitatively using bearing time records and quantitatively using signal-to-interference ratio. Qualitatively, CS exhibits lower levels of background interference than conventional beamforming. Furthermore, bearing time records show increasing, but tolerable, levels of background interference when the number of elements is decreased. For the full array, CS generates signal-to-interference ratio of 12 dB, but conventional beamforming only 8 dB. The superiority of CS over conventional beamforming is much more pronounced with undersampling. PMID:21974497

Edelmann, Geoffrey F; Gaumond, Charles F

2011-10-01

265

The Physics Question of the Week  

NSDL National Science Digital Library

The question of the week web site hosts questions about physics related to experiments and demonstrations. The answer to each question is posted at the end of the week along with a short video showing the experiment and a link to a page with more information about a related demonstration.

Berg, Richard E.

2007-11-10

266

Economic Impact of Block Island Race Week.  

National Technical Information Service (NTIS)

Block Island, an area of 11 square miles lies 15 miles off the Rhode Island Coast. Biennially since 1965, the Storm Trysail Club of New York has sponsored a week of yacht races at Block Island. The event, which takes place in the third week of June, comes...

J. F. Farrell

1973-01-01

267

Possible weekly variations in the thunderstorm activity  

Microsoft Academic Search

By using observation data at the Yakutsk station (East Siberia) and the superposed epoch technique it has been obtained that there is a weekly cycle in thunderstorm activity variations which can be related to the industrial activities. To estimate a degree of thunderstorm activity variations, the observation data of VLF-radionoises and electromagnetic impulses of thunderstorm nature are used. In weekly

Viktor A. Mullayarov; Rustam R. Karimov; Vladimir I. Kozlov; Igor N. Poddelsky

2005-01-01

268

Macalester College Problem of the Week  

NSDL National Science Digital Library

Back in 1968, Professor Joe Konhauser at Macalester College started a tradition by creating a math problem for his students every week. Since that time, this long-standing tradition has migrated to the web, and along with the current problem of the week, visitors can also view previous editions dating back to the fall of 1995. Currently, the problem of the week is overseen by Professor Stan Wagon, and visitors can browse through these problems as they see fit. The problems are meant to be accessible to first-year college students, so they can be used in a host of instructional settings, or potentially (one might imagine) as extra-credit. Visitors can sign up to receive the problem each week via email, and it is worth noting that the solution to each problem will be posted the following week.

Wagon, Stan.

269

Work Out at Work  

MedlinePLUS

Everyday Fitness Ideas from the National Institute on Aging at NIH www.nia.nih.gov/Go4Life Work Out at ... and enjoy the walk. l Join your company’s fitness center if there is one. Fit exercise into ...

270

The United States celebrates National Library Week  

NSDL National Science Digital Library

ALA Report: Poor Middle, High School Libraries Suffer the Most Budget Cutshttp://www.schoollibraryjournal.com/slj/home/890148-312/ala_report_poor_middle_high.html.cspClosing most Cobb libraries not realistichttp://www.ajc.com/opinion/closing-most-cobb-libraries-906121.htmlALA: 2011 State of America's Libraries Report [pdf]http://ala.org/ala/newspresscenter/mediapresscenter/americaslibraries2011/index.cfmThe Most Criticized Books! A Handy List From Your Libraryhttp://www.npr.org/blogs/thetwo-way/2011/04/11/135316133/the-most-criticized-books-a-handy-list-from-your-library@Your Libraryhttp://www.atyourlibrary.org/It's National Library Week, and libraries around the United States have much to celebrate. More and more patrons are coming in to their area libraries to check out e-books, read the newspapers, search for jobs online, and to take advantage of unique programs, such as special presentations and concerts. Flush times indeed, but along with rising patronage, public libraries are also facing major cutbacks in terms of funding. This week, the American Library Association (ALA) released its annual "State of America's Libraries" report, and there were a number of troubling signs within its pages. Perhaps the most troubling revelation was that middle and high school libraries in high poverty areas of the US suffered average spending cuts on information resources and collection size of 25.5 percent. The report also noted that total library staff hours declined across the United States, but there was an average increase of 0.8 hours per week among certified school librarians. While most observers tend to agree that libraries will continue to serve as important community gathering centers in the future, it remains to be seen what will be contained within their walls 10 or 20 years in the future.The first link will take visitors to a recent piece of reporting from National Public Radio (NPR) about the future of libraries, with specific reference to the growing popularity of e-books. The second link leads to a piece from the School Library Journal about the budgets cuts among libraries in high poverty areas. Moving on, the third link will whisk users away to an opinion piece by writer Margaret Johnson-Hodge about the importance of libraries in Cobb County, Georgia. The fourth link leads to the full text of the 2011 State of America's Libraries Report from the ALA. The fifth link leads to a report from NPR on the most frequently challenged books of 2010. This list includes titles such as "Brave New World" by Aldous Huxley and "Crank" by Ellen Hopkins. Finally, the last link leads to the homepage of the Campaign for America's Libraries, which provides information on local libraries, recommended books and music, and information on their mission and work.

Grinnell, Max

2011-04-15

271

Analyzing High Resolution Geoscience Data using Parallelism and Compression (Invited)  

NASA Astrophysics Data System (ADS)

Today's high-resolution climate datasets impose challenges in both storage space and I/O overhead. We explore parallel I/O and compression to address these challenges. The Parallel Analysis of GeOscience Data (pagaoda) toolkit is both an API for data-parallel analysis of geoscience climate data as well as a set of data-parallel processing tools based on this API. The API and the tools were designed first to support geodesic semi-structured NetCDF data, however they are generic enough to work with regularly gridded data as well. The command line tools are designed to mimic the NetCDF Operators but support both parallel IO and a combination of data and task parallelism. For large datasets, the single greatest performance bottleneck is IO. We describe multiple techniques we use to reduce the overhead of IO operations, namely the pseudo non-blocking interface of the parallel NetCDF library and compression. The techniques described can be applied generically to other applications using MPI-IO. We cover the current status of pagoda, compression techniques, and feature current performance information for high resolution data. Compression is promising for reducing storage space and I/O overhead. However, traditional compression algorithms, such as the LZW class compression, are designed mainly for text. These compression algorithms introduce high computation overhead and are not able to achieve high a compression ratio. We design compression algorithms specially customized for scientific data. Compared with traditional compression algorithms, our compression algorithm achieves a significantly higher compression ratio and introduces lower computation overhead. A naive architecture for incorporating compression is to first decompress data then perform computation on the decompressed data. Although this approach can reduce storage space, it hurts application performance. In our architecture, we pipeline the retrieval of compressed data from I/O devices, decompression of the data, and the computation on the decompressed data. Data decompression is overlapped with I/O operations. As a result, our architecture improves application performance by a factor close to the compression ratio for I/O bounded applications and can improve performance even for CPU bounded applications.

Daily, J.; Yin, J.

2013-12-01

272

Shock compression of formic acid  

NASA Astrophysics Data System (ADS)

Simple molecules such as formic acid, HCOOH, have been suggested to play important roles in the origin of life due to their high pressure and temperature chemistry. The hydrogen bonding characteristics and polymerization of HCOOH under static high pressure have been recently investigated using both molecular dynamics calculations and experimental work. These works suggest that symmetric hydrogen bonding of HCOOH (forming a linear chain polymer where all C-O bonds are equivalent) occurs at 16 - 21 GPa at room temperature. In order to examine the shock compression behavior of this simple carboxylic acid, we present a series of gas gun-driven plate impact experiments on formic acid with shock inputs in the range of 5.5 - 23.0 GPa. Using in-situ electromagnetic gauges, shock wave profiles (particle velocities) were measured at multiple positions as a function of shock input pressure, providing valuable information about its unreacted equation of state. No easily recognizable shock-induced reactions were observed in any of the four experiments, and the four points lie close to a universal liquid Hugoniot based only on the sound speed of formic acid.

Manner, Virginia W.; Sheffield, S. A.; Dattelbaum, Dana M.; Stahl, David B.

2012-03-01

273

Uterine Compression Sutures as an Effective Treatment for Postpartum Hemorrhage: Case Series  

PubMed Central

We evaluated the role of uterine compression sutures as a conservative treatment for postpartum hemorrhage (PPH) after failed medical treatment. We retrospectively reviewed the charts of all patients who delivered between 2003 and 2009 at a single tertiary care center and who underwent uterine compression sutures for PPH. Twelve women had uterine compression sutures for PPH. The mean age of the patients was 36.3 ± 5.2 years. The mean gestational age at delivery was 37.7 ± 2.0 weeks, and the average estimated blood loss was 2.1 ± 1.1 L. The mean procedure time to perform the uterine compression sutures was 9.3 ± 2.8 minutes. The success rate of compression sutures was 92% with only one failure resulting in a hysterectomy. Uterine compression sutures are an effective method for the treatment of PPH, thus avoiding hysterectomy and preserving potential fertility.

Al Riyami, Nihal; Hui, Dini; Herer, Elaine; Nevo, Ori

2011-01-01

274

Weekly cycle in particulate matter versus weekly cycle in precipitation over Switzerland  

NASA Astrophysics Data System (ADS)

During the last few years the question has been raised if there is a weekly cycle in climatological variables due to anthropogenic activity. In this study, particulate matter (PM) data and precipitation data from 17 Swiss weather stations are analyzed for weekly cycles with three different methods: a nonparametric statistical test, a Fourier analysis on the time series, and a comparison of the regular 7-day week with either a 6- or 8-day week. Results show a well-pronounced and statistical significant weekly cycle for PM but do not show any statistically significant weekly cycle for meteorological quantities such as precipitation.

Barmet, Peter; Kuster, Thomas; Muhlbauer, Andreas; Lohmann, Ulrike

2009-03-01

275

Perceptually Lossless Wavelet Compression  

NASA Technical Reports Server (NTRS)

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.

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

1996-01-01

276

Free compression tube. Applications  

NASA Astrophysics Data System (ADS)

During the flight of vehicles, their propulsion energy must overcome gravity, to ensure the displacement of air masses on vehicle trajectory, to cover both energy losses from the friction between a solid surface and the air and also the kinetic energy of reflected air masses due to the impact with the flying vehicle. The flight optimization by increasing speed and reducing fuel consumption has directed research in the aerodynamics field. The flying vehicles shapes obtained through studies in the wind tunnel provide the optimization of the impact with the air masses and the airflow along the vehicle. By energy balance studies for vehicles in flight, the author Ioan Rusu directed his research in reducing the energy lost at vehicle impact with air masses. In this respect as compared to classical solutions for building flight vehicles aerodynamic surfaces which reduce the impact and friction with air masses, Ioan Rusu has invented a device which he named free compression tube for rockets, registered with the State Office for Inventions and Trademarks of Romania, OSIM, deposit f 2011 0352. Mounted in front of flight vehicles it eliminates significantly the impact and friction of air masses with the vehicle solid. The air masses come into contact with the air inside the free compression tube and the air-solid friction is eliminated and replaced by air to air friction.

Rusu, Ioan

2012-11-01

277

Energy transfer in compressible turbulence  

NASA Technical Reports Server (NTRS)

This letter investigates the compressible energy transfer process. We extend a methodology developed originally for incompressible turbulence and use databases from numerical simulations of a weak compressible turbulence based on Eddy-Damped-Quasi-Normal-Markovian (EDQNM) closure. In order to analyze the compressible mode directly, the well known Helmholtz decomposition is used. While the compressible component has very little influence on the solenoidal part, we found that almost all of the compressible turbulence energy is received from its solenoidal counterpart. We focus on the most fundamental building block of the energy transfer process, the triadic interactions. This analysis leads us to conclude that, at low turbulent Mach number, the compressible energy transfer process is dominated by a local radiative transfer (absorption) in both inertial and energy containing ranges.

Bataille, Francoise; Zhou, YE; Bertoglio, Jean-Pierre

1995-01-01

278

Data Compression Techniques for Advanced Space Transportation Systems  

NASA Technical Reports Server (NTRS)

Advanced space transportation systems, including vehicle state of health systems, will produce large amounts of data which must be stored on board the vehicle and or transmitted to the ground and stored. The cost of storage or transmission of the data could be reduced if the number of bits required to represent the data is reduced by the use of data compression techniques. Most of the work done in this study was rather generic and could apply to many data compression systems, but the first application area to be considered was launch vehicle state of health telemetry systems. Both lossless and lossy compression techniques were considered in this study.

Bradley, William G.

1998-01-01

279

Compressive sampling in computed tomography: Method and application  

NASA Astrophysics Data System (ADS)

Since Donoho and Candes et al. published their groundbreaking work on compressive sampling or compressive sensing (CS), CS theory has attracted a lot of attention and become a hot topic, especially in biomedical imaging. Specifically, some CS based methods have been developed to enable accurate reconstruction from sparse data in computed tomography (CT) imaging. In this paper, we will review the progress in CS based CT from aspects of three fundamental requirements of CS: sparse representation, incoherent sampling and reconstruction algorithm. In addition, some potential applications of compressive sampling in CT are introduced.

Hu, Zhanli; Liang, Dong; Xia, Dan; Zheng, Hairong

2014-06-01

280

Magnetic compression laser driving circuit  

DOEpatents

A magnetic compression laser driving circuit is disclosed. The magnetic compression laser driving circuit compresses voltage pulses in the range of 1.5 microseconds at 20 kilovolts of amplitude to pulses in the range of 40 nanoseconds and 60 kilovolts of amplitude. The magnetic compression laser driving circuit includes a multi-stage magnetic switch where the last stage includes a switch having at least two turns which has larger saturated inductance with less core material so that the efficiency of the circuit and hence the laser is increased.

Ball, D.G.; Birx, D.; Cook, E.G.

1993-01-05

281

Uncommon upper extremity compression neuropathies.  

PubMed

Hand surgeons routinely treat carpal and cubital tunnel syndromes, which are the most common upper extremity nerve compression syndromes. However, more infrequent nerve compression syndromes of the upper extremity may be encountered. Because they are unusual, the diagnosis of these nerve compression syndromes is often missed or delayed. This article reviews the causes, proposed treatments, and surgical outcomes for syndromes involving compression of the posterior interosseous nerve, the superficial branch of the radial nerve, the ulnar nerve at the wrist, and the median nerve proximal to the wrist. PMID:23895725

Knutsen, Elisa J; Calfee, Ryan P

2013-08-01

282

Magnetic compression laser driving circuit  

DOEpatents

A magnetic compression laser driving circuit is disclosed. The magnetic compression laser driving circuit compresses voltage pulses in the range of 1.5 microseconds at 20 Kilovolts of amplitude to pulses in the range of 40 nanoseconds and 60 Kilovolts of amplitude. The magnetic compression laser driving circuit includes a multi-stage magnetic switch where the last stage includes a switch having at least two turns which has larger saturated inductance with less core material so that the efficiency of the circuit and hence the laser is increased.

Ball, Don G. (Livermore, CA); Birx, Dan (Brentwood, CA); Cook, Edward G. (Livermore, CA)

1993-01-01

283

Effect of Compression Ratio, Pressure, Temperature, and Humidity on Power  

NASA Technical Reports Server (NTRS)

Among other factors which affect the horsepower of an airplane engine are the atmospheric pressure, and consequently the altitude at which the engine is working, and the compression ratio, or cylinder volume divided by clearance volume. The tests upon which this report is based were selected from a large number of runs made during the intercomparison of various gasolines to determine the variation of horsepower with altitude at three different compression ratios. The test results and conclusions are presented in this report.

Dickinson, H C; James, W S; Anderson, G V; Brinkerhoff, V W

1919-01-01

284

Numerical simulation of 2D and 3D compressible flows  

NASA Astrophysics Data System (ADS)

The work deals with numerical solutions of 2D inviscid and laminar compressible flows in the GAMM channel and DCA 8% cascade, and of 3D inviscid compressible flows in a 3D modification of the GAMM channel (Swept Wing). The FVM multistage Runge-Kutta method and the Lax-Wendroff scheme (Richtmyer's form) with Jameson's artificial dissipation were applied to obtain the numerical solutions. The results are discussed and compared to other similar results and experiments.

Huml, Jaroslav; Kozel, Karel; P?íhoda, Jaromír

2013-02-01

285

NASA Space Science Mathematics: Weekly Math Problems  

NSDL National Science Digital Library

This page features weekly mathematics problem sets that are designed to teach intermediate and upper-level students about space weather. The downloadable problem sets include one or more math problems to be solved using the information provided, a teachers' guide or answer key, and an inquiry question about the results. The web page features the current week's problem set, sets from previous weeks, and an archive of problem sets from past years. There are also downloadable books of the 20 most interesting problems published each year.

286

Solar Week Thursday: Funnel the Sun  

NSDL National Science Digital Library

This is an activity during Solar Week, a twice-yearly event in March and October during which classrooms are able to interact with scientists studying the Sun. Outside of Solar Week, information, activities, and resources are archived and available online at any time. This is an activity about reflection. Learners will create a foil funnel to focus light that can be detected by various means. This activity is scheduled to occur during Thursday of Solar Week. An optional part of this activity recommends use of a digital multimeter, an amp meter, and/or a solar cell.

287

Solar Week Thursday: Ice Cube Meltdown  

NSDL National Science Digital Library

This is an activity during Solar Week, a twice-yearly event in March and October during which classrooms are able to interact with scientists studying the Sun. Outside of Solar Week, information, activities, and resources are archived and available online at any time. This is an activity about energy absorption and reflection. In this hands-on activity, learners will experiment with ways of making ice cubes melt at different rates by choosing and testing various materials with different color and reflective properties. This activity is scheduled to occur during Thursday of Solar Week, and it requires use of a sunny outdoor location for an extended period of time.

288

Solar Week Tuesday: The Effect on Earth  

NSDL National Science Digital Library

This is a short online reading associated with activities during Solar Week, a twice-yearly event in March and October during which classrooms are able to interact with scientists studying the Sun. Outside of Solar Week, information, activities, and resources are archived and available online at any time. Learners will read about how the vision of dogs, bees, and humans differs and how the electromagnetic spectrum plays a role in those differences. This activity is scheduled to occur during Tuesday of Solar Week.

289

Radiator debris removing apparatus and work machine using same  

DOEpatents

A radiator assembly includes a finned radiator core and a debris removing apparatus having a compressed air inlet and at least one compressed air outlet configured to direct compressed air through the radiator core. A work machine such as a wheel loader includes a radiator and a debris removing apparatus coupled with on-board compressed air and having at least one pressurized gas outlet configured to direct a gas toward the face of the radiator.

Martin, Kevin L. (Washburn, IL) [Washburn, IL; Elliott, Dwight E. (Chillicothe, IL) [Chillicothe, IL

2008-09-02

290

Information optimal compressive sensing: static measurement design.  

PubMed

The compressive sensing paradigm exploits the inherent sparsity/compressibility of signals to reduce the number of measurements required for reliable reconstruction/recovery. In many applications additional prior information beyond signal sparsity, such as structure in sparsity, is available, and current efforts are mainly limited to exploiting that information exclusively in the signal reconstruction problem. In this work, we describe an information-theoretic framework that incorporates the additional prior information as well as appropriate measurement constraints in the design of compressive measurements. Using a Gaussian binomial mixture prior we design and analyze the performance of optimized projections relative to random projections under two specific design constraints and different operating measurement signal-to-noise ratio (SNR) regimes. We find that the information-optimized designs yield significant, in some cases nearly an order of magnitude, improvements in the reconstruction performance with respect to the random projections. These improvements are especially notable in the low measurement SNR regime where the energy-efficient design of optimized projections is most advantageous. In such cases, the optimized projection design departs significantly from random projections in terms of their incoherence with the representation basis. In fact, we find that the maximizing incoherence of projections with the representation basis is not necessarily optimal in the presence of additional prior information and finite measurement noise/error. We also apply the information-optimized projections to the compressive image formation problem for natural scenes, and the improved visual quality of reconstructed images with respect to random projections and other compressive measurement design affirms the overall effectiveness of the information-theoretic design framework. PMID:23695314

Ashok, Amit; Huang, Liang-Chih; Neifeld, Mark A

2013-05-01

291

Kyphoplasty. A treatment for osteoporotic vertebral compression fractures.  

PubMed

Patients experience more than 700,000 osteoporotic vertebral compression fractures each year in the United States, primarily because of bone brittleness and the inability of the vertebrae to resist increased forces applied to them. Patients diagnosed with this type of fracture are given the option of conservative or operative treatment approaches. Although a typical compression fracture generally heals in 6 to 12 weeks, patients may be offered the kyphoplasty procedure, which reduces the fracture and stabilizes it with cement. Although this procedure is not without risk, it is deemed a safe and effective treatment option. This article reviews the indications, implications, and care provided to patients pursuing kyphoplasty after osteoporotic vertebral compression fracture. PMID:18046205

Hanna, Jim; Letizia, Marijo

2007-01-01

292

Compression and compression fatigue testing of composite laminates  

NASA Technical Reports Server (NTRS)

The effects of moisture and temperature on the fatigue and fracture response of composite laminates under compression loads were investigated. The structural laminates studied were an intermediate stiffness graphite-epoxy composite (a typical angle ply laimna liminate had a typical fan blade laminate). Full and half penetration slits and impact delaminations were the defects examined. Results are presented which show the effects of moisture on the fracture and fatigue strength at room temperature, 394 K (250 F), and 422 K (300 F). Static tests results show the effects of defect size and type on the compression-fracture strength under moisture and thermal environments. The cyclic tests results compare the fatigue lives and residual compression strength under compression only and under tension-compression fatigue loading.

Porter, T. R.

1982-01-01

293

Survey of Header Compression Techniques  

NASA Technical Reports Server (NTRS)

This report provides a summary of several different header compression techniques. The different techniques included are: (1) Van Jacobson's header compression (RFC 1144); (2) SCPS (Space Communications Protocol Standards) header compression (SCPS-TP, SCPS-NP); (3) Robust header compression (ROHC); and (4) The header compression techniques in RFC2507 and RFC2508. The methodology for compression and error correction for these schemes are described in the remainder of this document. All of the header compression schemes support compression over simplex links, provided that the end receiver has some means of sending data back to the sender. However, if that return path does not exist, then neither Van Jacobson's nor SCPS can be used, since both rely on TCP (Transmission Control Protocol). In addition, under link conditions of low delay and low error, all of the schemes perform as expected. However, based on the methodology of the schemes, each scheme is likely to behave differently as conditions degrade. Van Jacobson's header compression relies heavily on the TCP retransmission timer and would suffer an increase in loss propagation should the link possess a high delay and/or bit error rate (BER). The SCPS header compression scheme protects against high delay environments by avoiding delta encoding between packets. Thus, loss propagation is avoided. However, SCPS is still affected by an increased BER (bit-error-rate) since the lack of delta encoding results in larger header sizes. Next, the schemes found in RFC2507 and RFC2508 perform well for non-TCP connections in poor conditions. RFC2507 performance with TCP connections is improved by various techniques over Van Jacobson's, but still suffers a performance hit with poor link properties. Also, RFC2507 offers the ability to send TCP data without delta encoding, similar to what SCPS offers. ROHC is similar to the previous two schemes, but adds additional CRCs (cyclic redundancy check) into headers and improves compression schemes which provide better tolerances in conditions with a high BER.

Ishac, Joseph

2001-01-01

294

Compressed wavefront sensing.  

PubMed

We report on an algorithm for fast wavefront sensing that incorporates sparse representation for the first time in practice. The partial derivatives of optical wavefronts were sampled sparsely with a Shack-Hartman wavefront sensor (SHWFS) by randomly subsampling the original SHWFS data to as little as 5%. Reconstruction was performed by a sparse representation algorithm that utilized the Zernike basis. We name this method sparse Zernike (SPARZER). Experiments on real and simulated data attest to the accuracy of the proposed techniques as compared to traditional sampling and reconstruction methods. We have made the corresponding dataset and software freely available online. Compressed wavefront sensing offers the potential to increase the speed of wavefront acquisition and to defray the cost of SHWFS devices. PMID:24690703

Polans, James; McNabb, Ryan P; Izatt, Joseph A; Farsiu, Sina

2014-03-01

295

Gas compression apparatus  

NASA Technical Reports Server (NTRS)

Apparatus for transferring gas from a first container to a second container of higher pressure was devised. A free-piston compressor having a driving piston and cylinder, and a smaller diameter driven piston and cylinder, comprise the apparatus. A rod member connecting the driving and driven pistons functions for mutual reciprocation in the respective cylinders. A conduit may be provided for supplying gas to the driven cylinder from the first container. Also provided is apparatus for introducing gas to the driving piston, to compress gas by the driven piston for transfer to the second higher pressure container. The system is useful in transferring spacecraft cabin oxygen into higher pressure containers for use in extravehicular activities.

Terp, L. S. (inventor)

1977-01-01

296

Population attribute compression  

DOEpatents

An image population having a large number of attributes is processed to form a display population with a predetermined smaller number of attributes that represent the larger number of attributes. In a particular application, the color values in an image are compressed for storage in a discrete look-up table (LUT). Color space containing the LUT color values is successively subdivided into smaller volumes until a plurality of volumes are formed, each having no more than a preselected maximum number of color values. Image pixel color values can then be rapidly placed in a volume with only a relatively few LUT values from which a nearest neighbor is selected. Image color values are assigned 8 bit pointers to their closest LUT value whereby data processing requires only the 8 bit pointer value to provide 24 bit color values from the LUT.

White, James M. (Los Alamos, NM); Faber, Vance (Los Alamos, NM); Saltzman, Jeffrey S. (Los Alamos, NM)

1995-01-01

297

Compressibility of Nanocrystalline Forsterite  

SciTech Connect

We established an equation of state for nanocrystalline forsterite using multi-anvil press and diamond anvil cell. Comparative high-pressure and high-temperature experiments have been performed up to 9.6 GPa and 1,300 C. We found that nanocrystalline forsterite is more compressible than macro-powder forsterite. The bulk modulus of nanocrystalline forsterite is equal to 123.3 ({+-}3.4) GPa whereas the bulk modulus of macro-powder forsterite is equal to 129.6 ({+-}3.2) GPa. This difference is attributed to a weakening of the elastic properties of grain boundary and triple junction and their significant contribution in nanocrystalline sample compare to the bulk counterpart. The bulk modulus at zero pressure of forsterite grain boundary was determined to be 83.5 GPa.

Couvy, H.; Chen, J; Drozd, V

2010-01-01

298

Compressed Wavefront Sensing  

PubMed Central

We report on an algorithm for fast wavefront sensing that incorporates sparse representation for the first time in practice. The partial derivatives of optical wavefronts were sampled sparsely with a Shack-Hartmann wavefront sensor (SHWFS) by randomly subsampling the original SHWFS data to as little as 5%. Reconstruction was performed by a sparse representation algorithm that utilized the Zernike basis. We name this method SPARZER. Experiments on real and simulated data attest to the accuracy of the proposed techniques as compared to traditional sampling and reconstruction methods. We have made the corresponding data set and software freely available online. Compressed wavefront sensing offers the potential to increase the speed of wavefront acquisition and to defray the cost of SHWFS devices.

Polans, James; McNabb, Ryan P.; Izatt, Joseph A.; Farsiu, Sina

2014-01-01

299

Elementary Physical Education Weekly Lesson Plan. Kindergarten.  

ERIC Educational Resources Information Center

This curriculum guide is for the teaching of physical education to kindergarten students. Teaching procedures, warm-up activities, safety procedures, modifications, and athletic equipment needed are described for each of the specific activities in the weekly lesson plans. (CJ)

Anchorage Borough School District, AK.

300

This Week @ NASA - 11/5/10  

NASA Video Gallery

The Postponement of Mission STS-133 tops the billboard on This Week @ NASA. Also, EPOXI meets a Comet, NASA and LEGO build a future together, Administrator Bolden heralds ten years of ISS, KSC Twee...

301

High Energy Astrophysics Picture of the Week  

NSDL National Science Digital Library

Each week this site provides a new image from X-ray and Gamma ray astronomy. Information is provided about the object and the telescope that took the picture. Previous images are available in an archive.

Corcoran, Michael

2004-07-14

302

Highlights From PhUn Week 2007  

NSDL National Science Digital Library

This is an article from The Physiologist. "More than 100 APS physiologists volunteered their time in reaching out to more than 3000 students last November during Physiology Understanding Week (PhUn Week), the APS member-based annual outreach program to local area K-12 schools (http://www.PhUnWeek.org). APS members partnered with more than 70 teachers and science educators from across the nation to develop engaging classroom or campus presentations for students at all grade levels, from day care through twelfth grades. The following vignettes are only a few samples of the excitement and fun generated by the focus on the physiology of health and exercise during the first week in November. All events with the primary APS member and lead teacher coordinators are listed in Table 1.".

2008-02-01

303

Solar Week Thursday: Shoebox Solar Water Heater  

NSDL National Science Digital Library

This is an activity during Solar Week, a twice-yearly event in March and October during which classrooms are able to interact with scientists studying the Sun. Outside of Solar Week, information, activities, and resources are archived and available online at any time. This is an activity about reflection. In this hands-on activity, learners will build a solar water heater by lining a box with reflective material, adding a translucent cover, and adding water-filled cans that are painted black. The temperature of the water is taken and recorded every fifteen minutes. This activity can use the same solar cooker built for the Solar Week Thursday: Solar Pizza Box Cooker activity. This activity is scheduled to occur during Thursday of Solar Week, and it requires use of a sunny outdoor location for an extended period of time.

304

Solar Week Thursday: Solar Shadow Tool  

NSDL National Science Digital Library

This is an activity during Solar Week, a twice-yearly event in March and October during which classrooms are able to interact with scientists studying the Sun. Outside of Solar Week, information, activities, and resources are archived and available online at any time. This is an activity about telling time using the Sun. Learners will create a solar shadow tool and use it to chart changes in the Sun's altitude through the seasons. This activity is scheduled to occur during Thursday of Solar Week. The activity requires access to a sunny outdoor location over the course of several days, weeks, or months, as well as materials and equipment such as pine board, dowel rod piece, drill and drill bit, saw, bulls-eye level, small nails, and either wood glue or hot glue.

305

Visible Embryo: 12 weeks post ovulation  

NSDL National Science Digital Library

a comprehensive resource of information on human development at 12 weeks from ovulation, designed for both medical student and interested lay people. The Visible Embryo offers a detailed pictorial account of normal and abnormal development.

Carmen Arbona (Mouseworks)

2006-10-19

306

Foreign Language Week--Celebrate It!  

ERIC Educational Resources Information Center

Suggestions are given for activities to celebrate Foreign Language Week, including public awareness exhibits, teacher involvement, food-related activities, sports, festivals and fairs, round tables and discussions, library involvement, planning and organizing techniques, and publicity efforts. (MSE)

Allison, Mary L.

1982-01-01

307

Feature detection and fusion for intelligent compression  

NASA Astrophysics Data System (ADS)

In previous work a novel approach was described which used automatic target detection together with compression techniques to achieve intelligent compression by exploiting knowledge of the image content. In this paper an extension to this work is presented in which a set of standard feature detectors such as HV-quadtrees, approximate entropy and phase congruency are used as target discriminators. These detectors all attempt to find potential areas of interest within an image but will undoubtedly be slightly different in their estimates. A probabilistic (Bayesian belief) network is then used to fuse this information into a single hypothesis of interesting areas within an image. A wavelet- based decomposition can then be applied to the image in which selective destruction of wavelet coefficients is performed outside the cued areas of interest (in effect concentrating the wavelet information into the required areas) prior to the encoding with a version of the progressive SPIHT encoder. One of the difficulties with this approach can be when large quantities of wavelet coefficients are discarded, this can potentially lead to abrupt changes at a mask boundary resulting in (visually) undesirable effects in the reconstructed image. An improvement to this is to modify the fused feature image using morphology in order to arrive at a multi-level fuzzy mask. This can then be used to gradually reduce the significance of coefficients as the distance from the mask increases. Results will illustrate how this approach can be used for the detection and compression of airborne reconnaissance imagery.

Ducksbury, Paul G.; Varga, Margaret J.

2001-08-01

308

A weekly cycle in atmospheric carbon dioxide  

Microsoft Academic Search

We present a new statistic called the “Mean Symmetrized Residual” (MSR) for detection and quantification of a weekly cycle in measured daily atmospheric carbon dioxide (CO2). At the Mauna Loa Observatory in Hawaii, we conclude that CO2 concentrations, on average, are significantly lower (0.022 parts per million by volume, ppmv) on weekends (Saturday–Sunday) than during the rest of the week.

Randall S. Cerveny; Kevin J. Coakley

2002-01-01

309

Moving Object Completion on the Compressed Domain  

NASA Astrophysics Data System (ADS)

Moving object completion is a process of completing moving object's missing information based on local structures. Over the past few years, a number of computable algorithms of video completion have been developed, however most of these algorithms are based on the pixel domain. Little theoretical and computational work in video completion is based on the compressed domain. In this paper, a moving object completion method on the compressed domain is proposed. It is composed of three steps: motion field transferring, thin plate spline interpolation and combination. Missing space-time blocks will be completed by placing new motion vectors on them so that the resulting video sequence will have as much global visual coherence with the video portions outside the hole. The experimental results are presented to demonstrate the efficiency and accuracy of the proposed algorithm.

Yiwei, Jiang; de, Xu; Na, Liu; Congyan, Lang

310

Compressive multiple view projection incoherent holography.  

PubMed

Multiple view projection holography is a method to obtain a digital hologram by recording different views of a 3D scene with a conventional digital camera. Those views are digitally manipulated in order to create the digital hologram. The method requires a simple setup and operates under white light illuminating conditions. The multiple views are often generated by a camera translation, which usually involves a scanning effort. In this work we apply a compressive sensing approach to the multiple view projection holography acquisition process and demonstrate that the 3D scene can be accurately reconstructed from the highly subsampled generated Fourier hologram. It is also shown that the compressive sensing approach, combined with an appropriate system model, yields improved sectioning of the planes of different depths. PMID:21451634

Rivenson, Yair; Stern, Adrian; Rosen, Joseph

2011-03-28

311

Detecting double compression of audio signal  

NASA Astrophysics Data System (ADS)

MP3 is the most popular audio format nowadays in our daily life, for example music downloaded from the Internet and file saved in the digital recorder are often in MP3 format. However, low bitrate MP3s are often transcoded to high bitrate since high bitrate ones are of high commercial value. Also audio recording in digital recorder can be doctored easily by pervasive audio editing software. This paper presents two methods for the detection of double MP3 compression. The methods are essential for finding out fake-quality MP3 and audio forensics. The proposed methods use support vector machine classifiers with feature vectors formed by the distributions of the first digits of the quantized MDCT (modified discrete cosine transform) coefficients. Extensive experiments demonstrate the effectiveness of the proposed methods. To the best of our knowledge, this piece of work is the first one to detect double compression of audio signal.

Yang, Rui; Shi, Yun Q.; Huang, Jiwu

2010-02-01

312

Social Work Supervision  

Microsoft Academic Search

The paper updates a survey of Social Work supervision first conducted in 1973. In 1989 a national sample of N.A.S.W. members were contacted by mail. The sample consisted of 1500 direct service worker supervisees and 1500 supervisors. Questionnaire returns indicated that supervision was generally implemented in individual conferences scheduled once a week, lasting one to one and a half hours.

Alfred Kadushin

1993-01-01

313

Streaming Compression of Hexahedral Meshes  

SciTech Connect

We describe a method for streaming compression of hexahedral meshes. Given an interleaved stream of vertices and hexahedral our coder incrementally compresses the mesh in the presented order. Our coder is extremely memory efficient when the input stream documents when vertices are referenced for the last time (i.e. when it contains topological finalization tags). Our coder then continuously releases and reuses data structures that no longer contribute to compressing the remainder of the stream. This means in practice that our coder has only a small fraction of the whole mesh in memory at any time. We can therefore compress very large meshes - even meshes that do not file in memory. Compared to traditional, non-streaming approaches that load the entire mesh and globally reorder it during compression, our algorithm trades a less compact compressed representation for significant gains in speed, memory, and I/O efficiency. For example, on the 456k hexahedra 'blade' mesh, our coder is twice as fast and uses 88 times less memory (only 3.1 MB) with the compressed file increasing about 3% in size. We also present the first scheme for predictive compression of properties associated with hexahedral cells.

Isenburg, M; Courbet, C

2010-02-03

314

Data compression by wavelet transforms  

NASA Technical Reports Server (NTRS)

A wavelet transform algorithm is applied to image compression. It is observed that the algorithm does not suffer from the blockiness characteristic of the DCT-based algorithms at compression ratios exceeding 25:1, but the edges do not appear as sharp as they do with the latter method. Some suggestions for the improved performance of the wavelet transform method are presented.

Shahshahani, M.

1992-01-01

315

Utility Grade Compressed Air Systems  

Microsoft Academic Search

Industrial companies are continually faced with increasing competition, rising costs, and tighter margins. As manufacturers identify ways to reduce costs and improve their bottom line, one significant opportunity that is often overlooked is the compressed air system. Compressed air systems are typically the largest users of electricity in a manufacturing facility and need to be managed accordingly. Companies converting to

Jerry C. Eaton; LaMonte L. Wilder; Richard D. Feustel

2008-01-01

316

Piston reciprocating compressed air engine  

Microsoft Academic Search

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

Cestero

1987-01-01

317

Pressure Oscillations in Adiabatic Compression  

ERIC Educational Resources Information Center

After finding Moloney and McGarvey's modified adiabatic compression apparatus, I decided to insert this experiment into my physical chemistry laboratory at the last minute, replacing a problematic experiment. With insufficient time to build the apparatus, we placed a bottle between two thick textbooks and compressed it with a third textbook forced…

Stout, Roland

2011-01-01

318

Compression Shocks of Detached Flow  

NASA Technical Reports Server (NTRS)

It is known that compression shocks which lead from supersonic to subsonic velocity cause the flow to separate on impact on a rigid wall. Such shocks appear at bodies with circular symmetry or wing profiles on locally exceeding sonic velocity, and in Laval nozzles with too high a back pressure. The form of the compression shocks observed therein is investigated.

Eggink

1947-01-01

319

Adaptive efficient compression of genomes.  

PubMed

: 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. However, memory requirements of the current algorithms are high and run times often are slow. In this paper, we propose an adaptive, parallel and highly efficient referential sequence compression method which allows fine-tuning of the trade-off between required memory and compression speed. When using 12 MB of memory, our method is for human genomes on-par with the best previous algorithms in terms of compression ratio (400:1) and compression speed. In contrast, it compresses a complete human genome in just 11 seconds when provided with 9 GB of main memory, which is almost three times faster than the best competitor while using less main memory. PMID:23146997

Wandelt, Sebastian; Leser, Ulf

2012-01-01

320

Code compression for embedded systems  

Microsoft Academic Search

Memory is one of the most restricted resources in many modern embedded systems. Code compression can provide substantial savings in terms of size. In a compressed code CPU, a cache miss triggers the decompression of a main memory block, before it gets transferred to the cache. Because the code must be decompressible starting from any point (or at least at

Haris Lekatsas; Wayne Wolf

1998-01-01

321

Model-Based Compressive Sensing  

Microsoft Academic Search

Compressive sensing (CS) is an alternative to Shannon\\/Nyquist sampling for acquisition of sparse or compressible signals that can be well approximated by just K ? N elements from an N -dimensional basis. Instead of taking periodic samples, we measure inner products with M < N random vectors and then recover the signal via a sparsity-seeking optimization or greedy algorithm. The

Richard G. Baraniuk; Volkan Cevher; Marco F. Duarte; Chinmay Hegde

2008-01-01

322

Model-based compressive sensing  

Microsoft Academic Search

Compressive sensing (CS) is an alternative to Shannon\\/Nyquist sampling for the acquisition of sparse or compressible signals that can be well approximated by just K ¿ N elements from an N -dimensional basis. Instead of taking periodic samples, CS measures inner products with M < N random vectors and then recovers the signal via a sparsity-seeking optimization or greedy algorithm.

Richard G. Baraniuk; Volkan Cevher; Marco F. Duarte; Chinmay Hegde

2010-01-01

323

Data compression on the sphere  

NASA Astrophysics Data System (ADS)

Large data-sets defined on the sphere arise in many fields. In particular, recent and forthcoming observations of the anisotropies of the cosmic microwave background (CMB) made on the celestial sphere contain approximately three and fifty mega-pixels respectively. The compression of such data is therefore becoming increasingly important. We develop algorithms to compress data defined on the sphere. A Haar wavelet transform on the sphere is used as an energy compression stage to reduce the entropy of the data, followed by Huffman and run-length encoding stages. Lossless and lossy compression algorithms are developed. We evaluate compression performance on simulated CMB data, Earth topography data and environmental illumination maps used in computer graphics. The CMB data can be compressed to approximately 40% of its original size for essentially no loss to the cosmological information content of the data, and to approximately 20% if a small cosmological information loss is tolerated. For the topographic and illumination data compression ratios of approximately 40:1 can be achieved when a small degradation in quality is allowed. We make our SZIP program that implements these compression algorithms available publicly.

McEwen, J. D.; Wiaux, Y.; Eyers, D. M.

2011-07-01

324

Compression equations for mercury porosimetry  

NASA Astrophysics Data System (ADS)

Methods for obtaining isothermal pressure-volume data using a mercury porosimeter and for completely correcting this data for compression effects are described. The isothermal compressions of several liquids were measured with a 103 MPa (15,000 psi) mercury porosimeter using the principles described. The porosites and surface areas of several areas of several macroporous solids were accurately measured.

Smithwick, R. W., III

1982-05-01

325

Optimal prefetching via data compression  

Microsoft Academic Search

A form of the competitive philosophy is applied to the problem of prefetching to develop an optimal universal prefetcher in terms of fault ratio, with particular applications to large-scale databases and hypertext systems. The algorithms are novel in that they are based on data compression techniques that are both theoretically optimal and good in practice. Intuitively, in order to compress

J. S. Vitter; P. Krishnan

1991-01-01

326

Compressed sensing for face recognition  

Microsoft Academic Search

In this paper, we present a new approach to build a more robust and efficient face recognition system. The idea is to fit the face recognition task into the new mathematical theory and algorithm of compressed sensing framework. With its beautiful theoretical results from compressed sensing, the new face recognition framework stably gives a better performance with some advantages compared

Nhat Vo; Duc Vo; Subhash Challa; Bill Moran

2009-01-01

327

Analysis of clay layer compression  

NSDL National Science Digital Library

Students analyze time series data for long-term ground subsidence in response to dewatering. From this analysis, the students can back-figure the compressibility of a clay lens that is compressing, and the vertical hydraulic conductivity of the clay. The data may be downloaded from the book web site and imported into a spreadsheet for analysis.

Fitts, Charlie

328

Visual data compression for multimedia applications  

Microsoft Academic Search

The compression of visual information in the framework of multimedia applications is discussed. To this end, major approaches to compress still as well as moving pictures are reviewed. The most important objective in any compression algorithm is that of compression efficiency. High-compression coding of still pictures can be split into three categories: waveform, second-generation, and fractal coding techniques. Each coding

TOURADJ EBRAHIMI; MURAT KUNT

1998-01-01

329

Digital compression algorithms for HDTV transmission  

NASA Technical Reports Server (NTRS)

Digital compression of video images is a possible avenue for high definition television (HDTV) transmission. Compression needs to be optimized while picture quality remains high. Two techniques for compression the digital images are explained and comparisons are drawn between the human vision system and artificial compression techniques. Suggestions for improving compression algorithms through the use of neural and analog circuitry are given.

Adkins, Kenneth C.; Shalkhauser, Mary JO; Bibyk, Steven B.

1990-01-01

330

Understanding the basics of compressed air systems  

Microsoft Academic Search

Compressed air can be a manufacturing facility`s most expensive utility. Estimates and actual measurements of compressed air systems indicate ten to thirty-five percent of all compressed air generated is lost to leakage or improper use. Proper maintenance, sound design, and appropriate use of compressed air all contribute to cost effective and energy efficient compressed air systems. Sample calculations will be

Herron

1999-01-01

331

A Tutorial on MPEG\\/Audio Compression  

Microsoft Academic Search

ABSTRACT This tutorial covers the theory behind MPEG\\/audio compression This algorithm was developed by the Motion Picture Experts Group (MPEG), as an International Organization for Standardization (ISO) standard for the high fidelity compression of digital audio The MPEG\\/audio compression standard is one part of a multiple part standard that addresses the compression of video - 2), the compression of audio

Davis Pan

1995-01-01

332

Study on Compressed Biogas and Its Application to the Compression Ignition Dual Fuel Engine.  

National Technical Information Service (NTIS)

The paper introduces in detail the compression performance of biogas, the application of compressed biogas to the compression ignition engine and the possibility as well as the necessity of using compressed biogas. Moreover, the paper also goes further in...

C. Jiang T. Liu J. Zhong

1987-01-01

333

Low-cost still-picture compression chip set  

NASA Astrophysics Data System (ADS)

Image compression is used to handle large volume of digitized image data in order to minimize the time and cost required to store and transfer the digitized data. Image compression is one of the key components in emerging applications such as digital still video cameras, multimedia, color printers, video fax machines, and desktop publishing. This paper will describe the Zoran 031 image compression chip set. The chip set is comprised of the ZR36020 Discrete Cosine Transform (DCT) Processor and the ZR36031 Image Compression Coder/Decoder that work together to perform image compression and expansion. The chip set employs an algorithm for high quality compression of continuous-tone color or monochrome images, similar to the algorithm specified in the Joint Photographic Expert Group standard. The 031 chip set is targeted at cost-sensitive business and consumer applications such as digital still video cameras, color printers, color fax machines, and scanners. The architecture and the coding/decoding algorithm of the chip set as well as the add-in image compression PC board in which it is utilized will be discussed.

Razavi, Abbas; Shenberg, Isaac; Retter, Rafi; Friedlander, Rami; Jaliff, Ari; Frenkel, Miri; Nakagawa, Chihiro; Yamada, Hidetoshi

1992-04-01

334

[Compression of interference hyperspectral image based on FHALS-NTD].  

PubMed

A hyperspectral interference image compression algorithm based on fast hierarchical alternating least squares nonnegative tensor Tucker decomposition (FHALS-NTD) is proposed. Firstly, the interference hyperspectral image is decomposed by 3-D OPD lifting-based discrete wavelet transform (3D OPT-LDWT) in the OPD direction. Then, the 3D DWT sub-bands decomposed are used as a three order nonnegative tensor, which is decomposed by the proposed FHALS-NTD algorithm to obtain 8 core tensors and 24 unknown component matrices. Finally, to obtain the final compressed bit-stream, each unknown component matrices element is quantized, and each core tensor is encoded by the proposed bit-plane coding of significant coefficients. The experimental results showed that the proposed compression algorithm could be used for reliable and stable work and has good compressive property. In the compression ratio range from 32 : 1 to 4 : 1, the average peak signal to noise ratio of proposed compression algorithm is higher than 40 dB. Compared with traditional approaches, the proposed method could improve the average PSNR by 1.23 dB. This effectively improves the compression performance of hyperspectral interference image. PMID:23387199

Du, Li-Min; Li, Jin; Jin, Guang; Gao, Hui-Bin; Jin, Long-Xu; Zhang, Ke

2012-11-01

335

Low-Complexity Lossless and Near-Lossless Data Compression Technique for Multispectral Imagery  

NASA Technical Reports Server (NTRS)

This work extends the lossless data compression technique described in Fast Lossless Compression of Multispectral- Image Data, (NPO-42517) NASA Tech Briefs, Vol. 30, No. 8 (August 2006), page 26. The original technique was extended to include a near-lossless compression option, allowing substantially smaller compressed file sizes when a small amount of distortion can be tolerated. Near-lossless compression is obtained by including a quantization step prior to encoding of prediction residuals. The original technique uses lossless predictive compression and is designed for use on multispectral imagery. A lossless predictive data compression algorithm compresses a digitized signal one sample at a time as follows: First, a sample value is predicted from previously encoded samples. The difference between the actual sample value and the prediction is called the prediction residual. The prediction residual is encoded into the compressed file. The decompressor can form the same predicted sample and can decode the prediction residual from the compressed file, and so can reconstruct the original sample. A lossless predictive compression algorithm can generally be converted to a near-lossless compression algorithm by quantizing the prediction residuals prior to encoding them. In this case, since the reconstructed sample values will not be identical to the original sample values, the encoder must determine the values that will be reconstructed and use these values for predicting later sample values. The technique described here uses this method, starting with the original technique, to allow near-lossless compression. The extension to allow near-lossless compression adds the ability to achieve much more compression when small amounts of distortion are tolerable, while retaining the low complexity and good overall compression effectiveness of the original algorithm.

Xie, Hua; Klimesh, Matthew A.

2009-01-01

336

Studies on image compression and image reconstruction  

NASA Technical Reports Server (NTRS)

During this six month period our works concentrated on three, somewhat different areas. We looked at and developed a number of error concealment schemes for use in a variety of video coding environments. This work is described in an accompanying (draft) Masters thesis. In the thesis we describe application of this techniques to the MPEG video coding scheme. We felt that the unique frame ordering approach used in the MPEG scheme would be a challenge to any error concealment/error recovery technique. We continued with our work in the vector quantization area. We have also developed a new type of vector quantizer, which we call a scan predictive vector quantization. The scan predictive VQ was tested on data processed at Goddard to approximate Landsat 7 HRMSI resolution and compared favorably with existing VQ techniques. A paper describing this work is included. The third area is concerned more with reconstruction than compression. While there is a variety of efficient lossless image compression schemes, they all have a common property that they use past data to encode future data. This is done either via taking differences, context modeling, or by building dictionaries. When encoding large images, this common property becomes a common flaw. When the user wishes to decode just a portion of the image, the requirement that the past history be available forces the decoding of a significantly larger portion of the image than desired by the user. Even with intelligent partitioning of the image dataset, the number of pixels decoded may be four times the number of pixels requested. We have developed an adaptive scanning strategy which can be used with any lossless compression scheme and which lowers the additional number of pixels to be decoded to about 7 percent of the number of pixels requested! A paper describing these results is included.

Sayood, Khalid; Nori, Sekhar; Araj, A.

1994-01-01

337

[Once-weekly teriparatide treatment on osteoporosis].  

PubMed

Teriparatide (human PTH 1-34) transiently stimulate both bone formation and bone resorption and subsequently bone formation markers increased. The changes in bone turnover markers 24 h after each injection of once-weekly 56.5?g teriparatide were constant for 24 weeks. Once-weekly injections of teriparatide increased bone mineral density by 8.1% at the lumbar spine and reduced the risk of new vertebral fracture with a relative risk reduction of 80% compared to placebo for the patients with osteoporosis. Significant vertebral fracture risk reductions were also observed in the patients with high risk for fracture such as higher age, low bone mineral density, or sever vertebral fracture grade. Once-weekly teriparatide improved cortical bone parameters at proximal femur, may have the potential to prevent hip fracture. The duration of teriparatide treatment was limited. Therefore subsequent treatment for osteoporosis should be need. Bisphosphonates seem to be a useful choice as a subsequent treatment to once-weekly teriparatide. PMID:24369286

Nakano, Tetsuo

2014-01-01

338

Changing the Way We Work  

ERIC Educational Resources Information Center

A 21-hour working week is a long way from today's standard of 40 hours or more, but not so far-fetched when people consider the infinitely varied ways in which they actually spend their time. On average, people of working age spend 19.6 hours a week in paid employment and 20.4 hours in unpaid housework and childcare. These averages mask huge…

Coote, Anna

2010-01-01

339

Fiber Bragg Grating Compression Sensor System.  

National Technical Information Service (NTIS)

A fiber Bragg grating compression sensor and a flexure mount that is attached to the sensor to significantly enhance its compression sensitivity. By incorporating the flexure mount, compressive forces are converted to tensile forces allowing an entire new...

G. P. Behrmann D. W. Prather

2004-01-01

340

Compression relief engine brake  

SciTech Connect

A compression relief brake is described for four cycle internal-combustion engines, comprising: a pressurized oil supply; means for selectively pressurizing a hydraulic circuit with oil from the oil supply; a master piston and cylinder communicating with a slave piston and cylinder via the hydraulic circuit; an engine exhaust valve mechanically coupled to the engine and timed to open during the exhaust cycle of the engine the exhaust valve coupled to the slave piston. The exhaust valve is spring-based in a closed state to contact a valve seat; a sleeve frictionally and slidably disposed within a cavity defined by the slave piston which cavity communicates with the hydraulic circuit. When the hydraulic circuit is selectively pressurized and the engine is operating the sleeve entraps an incompressible volume of oil within the cavity to generate a displacement of the slave piston within the slave cylinder, whereby a first gap is maintained between the exhaust valve and its associated seat; and means for reciprocally activating the master piston for increasing the pressure within the previously pressurized hydraulic circuit during at least a portion of the expansion cycle of the engine whereby a second gap is reciprocally maintained between the exhaust valve and its associated seat.

Meneely, V.A.

1987-10-06

341

Working Mothers  

MedlinePLUS

... Life > Work & Play > Working Mothers Family Life Listen Working Mothers Article Body ?In the United States today, more ... compared to about one third in the 1970s. Working mothers are now the rule rather than the exception. ...

342

Data compression applied to HHVT  

NASA Technical Reports Server (NTRS)

A task order was written by the High Resolution, High Frame Rate Video Technology (HHVT) project engineers to study data compression techniques that could be applied to the HHVT system. Specifically, the goals of the HHVT data compression study are to accomplish the following: (1) Determine the downlink capabilities of the Space Shuttle and Space Station Freedom to support HHVT data (i.e., determine the maximum data rates and link availability); (2) Determine current and projected capabilities of high speed storage media to support HHVT data by determining their maximum data acquisition/transmission rates and volumes; (3) Identify which experiment in the HHVT Users' Requirement data base need data compression, based on the experiments' imaging requirements; (4) Select the best data compression technique for each of these users by identifying a technique that provides compression but minimizes distortion; and (5) Investigate state-of-the-art technologies for possible implementation of selected data compression techniques. Data compression will be needed because of the high data rates and larger volumes of data that will result from the use of digitized video onboard the Space Shuttle and Space Station Freedom.

Thompson, William K.

1990-01-01

343

Advances in compressible turbulent mixing  

SciTech Connect

This volume includes some recent additions to original material prepared for the Princeton International Workshop on the Physics of Compressible Turbulent Mixing, held in 1988. Workshop participants were asked to emphasize the physics of the compressible mixing process rather than measurement techniques or computational methods. Actual experimental results and their meaning were given precedence over discussions of new diagnostic developments. Theoretical interpretations and understanding were stressed rather than the exposition of new analytical model developments or advances in numerical procedures. By design, compressibility influences on turbulent mixing were discussed--almost exclusively--from the perspective of supersonic flow field studies. The papers are arranged in three topical categories: Foundations, Vortical Domination, and Strongly Coupled Compressibility. The Foundations category is a collection of seminal studies that connect current study in compressible turbulent mixing with compressible, high-speed turbulent flow research that almost vanished about two decades ago. A number of contributions are included on flow instability initiation, evolution, and transition between the states of unstable flow onset through those descriptive of fully developed turbulence. The Vortical Domination category includes theoretical and experimental studies of coherent structures, vortex pairing, vortex-dynamics-influenced pressure focusing. In the Strongly Coupled Compressibility category the organizers included the high-speed turbulent flow investigations in which the interaction of shock waves could be considered an important source for production of new turbulence or for the enhancement of pre-existing turbulence. Individual papers are processed separately.

Dannevik, W.P.; Buckingham, A.C.; Leith, C.E. [eds.

1992-01-01

344

Vehicle Technologies' Fact of the Week 2012  

SciTech Connect

Each week the U.S. Department of Energy s Vehicle Technology Office (VTO) posts a Fact of the Week on their website: http://www1.eere.energy.gov/vehiclesandfuels/ . These Facts provide statistical information, usually in the form of charts and tables, on vehicle sales, fuel economy, gasoline prices, and other transportation-related trends. Each Fact is a stand-alone page that includes a graph, text explaining the significance of the data, the supporting information on which the graph was based, and the source of the data. A link to the current week s Fact is available on the VTO homepage, but older Facts are archived and still available at: http://www1.eere.energy.gov/vehiclesandfuels/facts/. This report is a compilation of the Facts that were posted during calendar year 2012. The Facts were written and prepared by staff in Oak Ridge National Laboratory's Center for Transportation Analysis.

Davis, Stacy Cagle [ORNL; Diegel, Susan W [ORNL; Moore, Sheila A [ORNL; Boundy, Robert Gary [ORNL

2013-02-01

345

Non-observation RINEX compression  

NASA Astrophysics Data System (ADS)

RINEX format is a result of an effort to standardize exchanging GNSS related data in human readable receiver independent format. Besides observation data, RINEX is also de facto standard for exchanging navigation message or meteorological data. The paper describes simple compression methods for navigation messages and meteorological data files. Both formats have their specific features, therefore different methods were used. Followed by standard compression the algorithms reduce the file size by more than 20 percent compared to standard compression. Thanks to the properties of weather and regular parameter observations it allows to reduce the file size of meteorological RINEX to a mere fraction of its original size.

Bezru?ka, Juraj

2013-12-01

346

Compressive adaptive computational ghost imaging  

PubMed Central

Compressive sensing is considered a huge breakthrough in signal acquisition. It allows recording an image consisting of N2 pixels using much fewer than N2 measurements if it can be transformed to a basis where most pixels take on negligibly small values. Standard compressive sensing techniques suffer from the computational overhead needed to reconstruct an image with typical computation times between hours and days and are thus not optimal for applications in physics and spectroscopy. We demonstrate an adaptive compressive sampling technique that performs measurements directly in a sparse basis. It needs much fewer than N2 measurements without any computational overhead, so the result is available instantly.

A?mann, Marc; Bayer, Manfred

2013-01-01

347

A novel GDSII compression technique  

NASA Astrophysics Data System (ADS)

With the ever increasing layout data size due to finer geometries and resolution enhancement techniques such as OPC and PSM, handling several tens of gigabytes of GDSII data is becoming very difficult. While new efficient OASIS format is being proposed to replace it, GDSII is here to stay for next several years. This paper discusses two approaches by which the GDSII data can be handled effectively. Reversible compression will be able to produce original GDSII file bit-by-bit and can produce compression of around 20 times. Irreversible compression can produce functionally equivalent GDSII after decompression.

Pereira, Mark; Baruah, Barsha

2005-11-01

348

Streaming Compression of Tetrahedral Volume Meshes  

SciTech Connect

Geometry processing algorithms have traditionally assumed that the input data is entirely in main memory and available for random access. This assumption does not scale to large data sets, as exhausting the physical memory typically leads to IO-inefficient thrashing. Recent works advocate processing geometry in a 'streaming' manner, where computation and output begin as soon as possible. Streaming is suitable for tasks that require only local neighbor information and batch process an entire data set. We describe a streaming compression scheme for tetrahedral volume meshes that encodes vertices and tetrahedra in the order they are written. To keep the memory footprint low, the compressor is informed when vertices are referenced for the last time (i.e. are finalized). The compression achieved depends on how coherent the input order is and how many tetrahedra are buffered for local reordering. For reasonably coherent orderings and a buffer of 10,000 tetrahedra, we achieve compression rates that are only 25 to 40 percent above the state-of-the-art, while requiring drastically less memory resources and less than half the processing time.

Isenburg, M; Lindstrom, P; Gumhold, S; Shewchuk, J

2005-11-21

349

Image compression quality rating using anchored scales  

NASA Astrophysics Data System (ADS)

Traditional image quality rating schemes use descriptive scales applicable to wide ranges of quality. These scales, based on equal interval verbal descriptors, cannot be used for restricted ranges of quality now encountered in image compression studies. Although numerical category scales have been successfully used in some studies for quantifying small variations in quality arising from lossy image compression, problems arise in more general image coding applications. In this work, we propose a double anchored numerical category scale based on a 3-context visual assessment scheme for image coding applications. The goal is to devise a common subjective scale applicable to a set of images produced from multiple scenes compressed by multiple coding algorithms. Therefore, the contexts are in the use of distinct coders and distinct images. The first two contexts, using a specific image scene, are the visibility of specific coder induced artifacts and the visibility of artifacts arising from different coders. In the third context, the artifact visibility is in terms of the content of different image scenes. Separate scales are obtained for images differing in scene content and for each coding algorithm, using numerical category scaling with explicit high and low anchors. These scales are linked using pairwise matching techniques to obtain a robust image quality sale.

Avadhanam, Niranjan; Algazi, V. Ralph

1998-04-01

350

First Few Weeks on Campus. Prevention Update  

ERIC Educational Resources Information Center

Every fall, college and university campuses and communities brace for the onslaught of new and returning students. For first-year students, anecdotal evidence suggests that the first six weeks of enrollment are critical to success. Because many students initiate heavy drinking during these early days of college, the potential exists for excessive…

Higher Education Center for Alcohol, Drug Abuse, and Violence Prevention, 2010

2010-01-01

351

Twelve weeks of coronary artery disease.  

PubMed Central

Osler said the components of the student spirit are humility, confidence, pride and hope. In this retrospective look at 12 weeks spent on a cardiology ward, medical student Paul Fedak recounts his experiences concerning a patient diagnosed with terminal coronary artery disease.

Fedak, P W

1996-01-01

352

Intelligent Golden Week Holiday Tourism Forecasting  

Microsoft Academic Search

In this paper, we investigate how to apply mobile multi-agent theory and technology in the design and implementation of the national golden week holiday tourism forecast system, which runs in an open and dynamic environment. We define different kinds of agents with different functions. The agents cooperate and coordinate with each other to complete the common goal of the system

Du Junping; Zuo Min; Guo Wensheng

2006-01-01

353

78 FR 30729 - World Trade Week, 2013  

Federal Register 2010, 2011, 2012, 2013

...8983 of May 17, 2013 World Trade Week, 2013 By...create good, middle-class jobs right here in America...do that is by boosting manufacturing and expanding trade that...services all around the world. We have made important...into a thriving middle class. We can start by...

2013-05-22

354

Maths Week Ireland Activities and Puzzles  

NSDL National Science Digital Library

This set of recreational math activities for students of all ages is hosted by Maths Week Ireland, the annual gathering and competition of math students from all over Ireland. Here you will find puzzles, art, magic tricks and resources for holding math events.

2013-01-01

355

76 FR 29139 - World Trade Week, 2011  

Federal Register 2010, 2011, 2012, 2013

...Proclamation 8677 of May 13, 2011 World Trade Week, 2011 By the President of the...to look beyond our borders to supply the world with innovative and technologically advanced...United States are tied to exports, and our world continues to grow more...

2011-05-19

356

Air Quality Awareness Week, Event Planning Kit.  

National Technical Information Service (NTIS)

Air Quality Awareness Week 2007 has been designated as April 30 May 4. This timeframe corresponds with the beginning of ozone season and makes for a great opportunity to engage your community in air quality awareness activities. Air quality awareness is m...

2007-01-01

357

3 CFR 8865 - Proclamation 8865 of September 14, 2012. National Farm Safety and Health Week, 2012  

Code of Federal Regulations, 2013 CFR

...producers who rise before the dawn, entrepreneurs who bring ideas to market, and working men and women who build the American dream with their bare hands. This week, we honor their tireless efforts and rededicate ourselves to equipping our...

2013-01-01

358

Compressed Medical Gases Guideline (Revised).  

National Technical Information Service (NTIS)

The guideline describes practices and procedures for compressed medical gas (CMG) fillers (including companies engaged in home respiratory services) that constitute acceptable means of complying with certain sections of the current good manufacturing prac...

1989-01-01

359

Data compression opportunities in EOSDIS  

NASA Technical Reports Server (NTRS)

The Earth Observing System Data and Information System (EOSDIS) is described in terms of its data volume, data rate, and data distribution requirements. Opportunities for data compression in EOSDIS are discussed.

Kobler, Ben; Berbert, John

1993-01-01

360

General Consideration of Energy Compression.  

National Technical Information Service (NTIS)

This general treatment of energy compression deals with some of the fundamental considerations involved in such a process. Discussed are: (1) the need for complementary energy modes such as magnetic electric or kinetic energy modes among which to transfer...

O. S. Zucker

1977-01-01

361

Bridge Types: Tensile & Compressive Forces  

NSDL National Science Digital Library

Students explore how tension and compression forces act on three different bridge types. Using sponges, cardboard and string, they create models of beam, arch and suspension bridges and apply forces to understand how they disperse or transfer these loads.

Integrated Teaching And Learning Program

362

Compression fractures of the back  

MedlinePLUS

... Meirhaeghe J, et al. Efficacy and safety of balloon kyphoplasty compared with non-surgical care for vertebral compression fracture (FREE): a randomised controlled trial. Lancet . 2009;373(9668):1016-24.

363

Efficient Decoding of Compressed Data.  

ERIC Educational Resources Information Center

Discusses the problem of enhancing the speed of Huffman decoding of compressed data. Topics addressed include the Huffman decoding tree; multibit decoding; binary string mapping problems; and algorithms for solving mapping problems. (22 references) (LRW)

Bassiouni, Mostafa A.; Mukherjee, Amar

1995-01-01

364

Fiber Composite Columns under Compression.  

National Technical Information Service (NTIS)

The micromechanics of fiber composite columns under compression is investigated theoretically. The model is based on the assumption that the fiber buckles inside the matrix under critical load. In the postbuckling range the fiber is considered as a beam o...

Y. C. B. Fung Y. N. Lanir

1971-01-01

365

Compressibility effects in turbulence modeling  

NASA Technical Reports Server (NTRS)

Numerical turbulence modeling is discussed with attention given to fluid property variations caused by compressibility in an adiabatic flow. The models are considered in terms of integral quantities expressed by ordinary differential equations and by those formulated as partial differential equations. Compressibility corrections for both integral and partial differential methods are reviewed. Eddy-viscosity models are explored for their capability to characterize the mass-weighted Reynolds stress, which can be accounted for with primitive and/or mass-weighted variables. Compressible flow simulations are currently constrained to low Re and zero mean dilation. The effects of compressibility are defined in wave number space by resolving the Fourier transforms of the velocity vectors into components which are perpendicular and parallel to the wave number vector. Statistical correlations then permit obtaining a value for each contribution.

Rubesin, M. W.

1982-01-01

366

High Voltage Flux Compression Generators.  

National Technical Information Service (NTIS)

Helical magnetic flux compression generators (HFCGs) have been in use for about five decades. There remain limitations to their performance. Recently and for the first time, calculations of high accuracy of HFCG output have been made. The calculated resul...

D. M. Chato G. F. Kiutu J. B. Chase

2008-01-01

367

Mechanisms in Compressible Cake Filtration.  

National Technical Information Service (NTIS)

Basic mechanisms influencing filtration dewatering of compressible water and wastewater sludges were examined. Results revealed many hitherto unappreciated aspects of filtration dewatering and pointed out the lack of reliability of present means for chara...

R. I. Dick

1989-01-01

368

Evolution of some Los Alamos flux compression programs  

SciTech Connect

When we were approached to give a general discussion of some aspects of the Los Alamos flux compression program, we decided to present historical backgrounds of a few topics that have some relevance to programs that we very much In the forefront of activities going on today. Of some thirty abstracts collected at Los Alamos for this conference, ten of them dealt with electromagnetic acceleration of materials, notably the compression of heavy liners, and five dealt with plasma compression. Both of these topics have been under investigation, off and on, from the time a formal flux compression program was organized at Los Alamos. We decided that a short overview of work done In these areas would be of some interest. Some of the work described below has been discussed in Laboratory reports that, while referenced and available, are not readily accessible. For completeness, some previously published, accessible work Is also discussed but much more briefly. Perhaps the most striking thing about the early work In these two areas is how primitive much of it was when compared to the far more sophisticated, related activities of today. Another feature of these programs, actually for most programs, Is their cyclic nature. Their relevance and/or funding seems to come land go. Eventually, many of the older programs come back into favor. Activities Involving the dense plasma focus (DPF), about which some discussions will be given later, furnish a classic example of this kind, coming Into and then out of periods of heightened interest. We devote the next two sections of this paper to a review of our work In magnetic acceleration of solids and of plasma compression. A final section gives a survey of our work In which thin foils are imploded to produce intense quantities of son x-rays. The authors are well aware of much excellent work done elsewhere In all of these topics, but partly because of space limitations, have confined this discussion to work done at Los Alamos.

Fowler, C.M.; Goforth, J.H.

1996-12-31

369

Hyperelastic Material Properties of Mouse Skin under Compression  

PubMed Central

The skin is a dynamic organ whose complex material properties are capable of withstanding continuous mechanical stress while accommodating insults and organism growth. Moreover, synchronized hair cycles, comprising waves of hair growth, regression and rest, are accompanied by dramatic fluctuations in skin thickness in mice. Whether such structural changes alter skin mechanics is unknown. Mouse models are extensively used to study skin biology and pathophysiology, including aging, UV-induced skin damage and somatosensory signaling. As the skin serves a pivotal role in the transfer function from sensory stimuli to neuronal signaling, we sought to define the mechanical properties of mouse skin over a range of normal physiological states. Skin thickness, stiffness and modulus were quantitatively surveyed in adult, female mice (Mus musculus). These measures were analyzed under uniaxial compression, which is relevant for touch reception and compression injuries, rather than tension, which is typically used to analyze skin mechanics. Compression tests were performed with 105 full-thickness, freshly isolated specimens from the hairy skin of the hind limb. Physiological variables included body weight, hair-cycle stage, maturity level, skin site and individual animal differences. Skin thickness and stiffness were dominated by hair-cycle stage at young (6–10 weeks) and intermediate (13–19 weeks) adult ages but by body weight in mature mice (26–34 weeks). Interestingly, stiffness varied inversely with thickness so that hyperelastic modulus was consistent across hair-cycle stages and body weights. By contrast, the mechanics of hairy skin differs markedly with anatomical location. In particular, skin containing fascial structures such as nerves and blood vessels showed significantly greater modulus than adjacent sites. Collectively, this systematic survey indicates that, although its structure changes dramatically throughout adult life, mouse skin at a given location maintains a constant elastic modulus to compression throughout normal physiological stages.

Wang, Yuxiang; Marshall, Kara L.; Baba, Yoshichika; Gerling, Gregory J.; Lumpkin, Ellen A.

2013-01-01

370

Diagnoses of coaxial probes in shock compression.  

PubMed

A miniature diagnostic apparatus, which consists of a target, a guiding tube, a nail-gun, and a simple base, has been developed in the proposed research to estimate batches of pinlike coaxial probes with selectable collision speeds, 198.3, 361.0, and 420.6 mps, corresponding to thrust capabilities of certain minibullets. This work aims at filling the gap between typical two stage light gas gun (>500 mps) and pendulum machine (<100 mps) with low cost and risk in realistic shock compressions. As a part of the experiment, the kappa coefficient and the statistical agreement and reliability are all evaluated. PMID:19566210

Sun, Yue; Ci, Jiaxiang; Yi, Pengfei; Zhang, Hongrun

2009-06-01

371

Compression strength of composite primary structural components  

NASA Astrophysics Data System (ADS)

A status report of work performed during the period May 1, 1992 to October 31, 1992 is presented. Research was conducted in three areas: delamination initiation in postbuckled dropped-ply laminates; stiffener crippling initiated by delamination; and pressure pillowing of an orthogonally stiffened cylindrical shell. The geometrically nonlinear response and delamination initiation of compression-loaded dropped-ply laminates is analyzed. A computational model of the stiffener specimens that includes the capability to predict the interlaminar response at the flange free edge in postbuckling is developed. The distribution of the interacting loads between the stiffeners and the shell wall, particularly at the load transfer at the stiffener crossing point, is determined.

Johnson, Eric R.

1992-10-01

372

Phase II randomized trial of weekly and every-3-week ixabepilone in metastatic breast cancer patients.  

PubMed

This multicenter, open-label, randomized phase II trial compared the efficacy and tolerability of weekly ixabepilone versus the standard 3 weekly dosing regimen. Patients with human epidermal growth factor receptor 2-negative, metastatic breast cancer (MBC) were randomly assigned to receive either ixabepilone 16 mg/m(2) as a 1-h intravenous (IV) infusion weekly on days 1, 8, and 15 of a 28-day cycle (1 week off therapy; n = 85), or 40 mg/m(2) as a 3-h IV infusion on day 1 of a 21-day cycle (n = 91), until disease progression or unacceptable toxicity. Randomization was stratified by (i) measurable versus nonmeasurable (evaluable) disease, (ii) ?two versus >two prior chemotherapy regimens for MBC, and (iii) hormone receptor (HR)-positive versus HR-negative breast cancer. The primary endpoint was rate of progression-free survival (PFS) at 6 months. Of 176 randomized patients, 171 were treated. The 6-month PFS rate was significantly higher in patients treated with ixabepilone every 3 weeks (42.7, 95 % confidence interval [CI] 31.5-53.5) compared with those who received ixabepilone weekly (28.6, 95 % CI 18.9-38.9; log-rank P = 0.03). Every-3-week dosing significantly prolonged median PFS versus weekly dosing (5.3 vs. 2.9 months; log-rank P = 0.05). The every-3-week regimen was associated with higher rates of grade 3/4 toxicities, particularly neutropenia (38.2 vs. 6.1 %) and a higher rate of patient withdrawal due to adverse events. These results suggest that every-3-week ixabepilone is more effective than weekly treatment in MBC, albeit with more toxicity. PMID:24166282

Smith, John W; Vukelja, Svetislava; Rabe, Amy; Wentworth-Hartung, Nicole; Koutrelakos, Nicholas; Shao, Spencer H; Whittaker, Thomas; Wang, Yunfei; Asmar, Lina; McDowell, Diane Opatt; Mukhopadhyay, Pralay; O'Shaughnessy, Joyce

2013-11-01

373

AFIS data compression: an example of how domain specific compression algorithms can produce very high compression ratios  

Microsoft Academic Search

This article describes the development and implementation of a data compression algorithm designed specifically for fingerprints, referred to as GBP compression. The algorithm is herein discussed. Data Compression algorithms can be designed for general applications, meaning the input data is unknown. This is more commonly referred to as generic data. [LI01] Or, data compression algorithms can be designed for specific

Givon Zirkind

2007-01-01

374

PERSISTENT EFFECTS OF REPEATED INHALATION OF TOLUENE: 4 WEEKS VS. 13 WEEKS.  

EPA Science Inventory

Understanding and predicting the extent of neurotoxic damage from repeated exposure to volatile organic compounds (VOCs) is a problem for many EPA programs. Eighty adult, male Long-Evans rats inhaled toluene (0, 10, 100, or 1000 ppm) 6 hr/day, 5 days/week for 4 weeks in a systema...

375

Austin Community College Eight-Week Course Feedback Survey: First Eight-Week Session, Fall 1998.  

ERIC Educational Resources Information Center

Pre- and post-course surveys of faculty and students participating in 8-week format courses at Austin Community College (ACC) in fall 1998 yielded the following recommendations: (1) offer more 8-week classes at more locations and class times; (2) build in class meetings to compensate for any time lost to holidays; (3) piggy-back, in the first and…

Austin Community Coll., TX.

376

Inferences of weekly cycles in summertime rainfall  

NASA Astrophysics Data System (ADS)

In several continental regions a weekly cycle of air pollution aerosols has been observed. It is usually characterized by concentration minima on weekends (Saturday and Sunday) and maxima on weekdays (Tuesday-Friday). Several studies have associated varying aerosol concentrations with precipitation production and attempted to determine whether or not there is a corresponding weekly cycle of precipitation. Results to date have been mixed. Here we examine a 12 year national composited radar data set for evidence of weekly precipitation cycles during the warm season (June-August). Various statistical quantities are calculated and subjected to "bootstrap" testing in order to assess significance. In many parts of the United States, warm season precipitation is relatively infrequent, with a few extreme events contributing to a large percentage of the total 12 year rainfall. For this reason, the statistics are often difficult to interpret. The general area east of the Mississippi River and north of 37°N contains regions where 25%-50% daily rainfall increases are inferred for weekdays (Tuesday-Friday) relative to weekends. The statistics suggest that western Pennsylvania is the largest and most likely contiguous region to have a weekly cycle. Parts of northern Florida and southeastern coastal areas infer a reverse-phase cycle, with less rainfall during the week than on weekends. Spot checks of surface rain gauge data confirm the phase of these radar-observed anomalies in both Pennsylvania and Florida. While there are indications of a weekly cycle in other locations of the United States, the degree of confidence is considerably lower. There is a strong statistical inference of weekday rainfall maxima over a net 8% of the area examined, which is approximately twice the area of cities. Future examination of lofted aerosol content, related condensation/ice nuclei spectra, and knowledge of the convective dynamical regime are needed in order to assess how anthropogenic aerosols may affect rainfall at urban and regional scales. If radar is the primary method of observation, it is also necessary to examine the effects of variable aerosol content on the parametric relationship between rainfall rate and radar reflectivity factor. Polarimetric radar observations could also serve to verify microphysical-dynamical hypotheses regarding precipitation production.

Tuttle, John D.; Carbone, Richard E.

2011-10-01

377

Performance Enhancement Technology for the Vapor Compression Refrigeration Cycle  

NASA Astrophysics Data System (ADS)

High efficiency refrigerator have been developed. For energy saving that is concerned with against global warming, performance enhancement of vapor compression refrigerator is required in field of air condition and refrigeration facility. In this paper, a review of recent performance enhancement technologies for the vapor compression refrigeration cycle is presented. This review contains high performance cycles of large sized centrifugal chiller, small to middle sized chiller and packaged air conditioner. Moreover, researches and developments of the refrigeration cycle recovering throttling loss, applications of ejector to boost in compressor suction pressure and to recirculate vapor refrigerant in the evaporator for heat transfer enhancement, and applications of expander to employ expansion work for compression work, are reviewed.

Man'o, Tatsunori

378

Expanding Window Compressed Sensing for Non-Uniform Compressible Signals  

PubMed Central

Many practical compressible signals like image signals or the networked data in wireless sensor networks have non-uniform support distribution in their sparse representation domain. Utilizing this prior information, a novel compressed sensing (CS) scheme with unequal protection capability is proposed in this paper by introducing a windowing strategy called expanding window compressed sensing (EW-CS). According to the importance of different parts of the signal, the signal is divided into several nested subsets, i.e., the expanding windows. Each window generates its own measurements using a random sensing matrix. The more significant elements are contained by more windows, so they are captured by more measurements. This design makes the EW-CS scheme have more convenient implementation and better overall recovery quality for non-uniform compressible signals than ordinary CS schemes. These advantages are theoretically analyzed and experimentally confirmed. Moreover, the EW-CS scheme is applied to the compressed acquisition of image signals and networked data where it also has superior performance than ordinary CS and the existing unequal protection CS schemes.

Liu, Yu; Zhu, Xuqi; Zhang, Lin; Cho, Sung Ho

2012-01-01

379

Vehicle Technologies' Fact of the Week 2011  

SciTech Connect

Each week the U.S. Department of Energy s Vehicle Technology Program (VTP) posts a Fact of the Week on their website: http://www1.eere.energy.gov/vehiclesandfuels/. These Facts provide statistical information, usually in the form of charts and tables, on vehicle sales, fuel economy, gasoline prices, and other transportation-related trends. Each Fact is a stand-alone page that includes a graph, text explaining the significance of the data, the supporting information on which the graph was based, and the source of the data. A link to the current Fact is available Monday through Friday on the VTP homepage, but older Facts are archived and still available at: http://www1.eere.energy.gov/vehiclesandfuels/facts/. This report is a compilation of the Facts that were posted during calendar year 2011. The Facts were written and prepared by staff in Oak Ridge National Laboratory's Center for Transportation Analysis.

Davis, Stacy Cagle [ORNL; Diegel, Susan W [ORNL; Boundy, Robert Gary [ORNL

2012-04-01

380

Citizen weeks or the psychologizing of citizenship.  

PubMed

Arland Deyett Weeks (1871-1936) was an American educator and social reformer who published The Psychology of Citizenship in 1917 with the intention of compiling the psychological, psychobiological, and psychosocial knowledge needed for governing modern democratic Western industrialized societies, as well as offering suggestions for intervention and social reform in the educational, legal, and occupational domains. His point of view can be placed within the progressive social and intellectual movement that characterized the policies of the United States in the first decade of the 20th century. His sociopolitical ideas were fed by transcendental and pragmatic sources, especially with respect to the way of dealing with tension between the individual and the collective. Modern psychological techniques (occupational, educational, legal psychology, etc.) nourished his reform program. In this article, we contextualize Weeks's book within these ideas and show its historical significance in the sociocultural and intellectual context that gave it meaning. PMID:23394177

Loredo-Narciandi, José Carlos; Castro-Tejerina, Jorge

2013-02-01

381

Two-point closures for weakly compressible turbulence  

NASA Astrophysics Data System (ADS)

The aim of the present paper is to address the problem of homogeneous isotropic compressible turbulence within the framework of two-point statistical closures. In order to simplify the description, weak compressibility assumptions are first introduced in the equations governing the fluctuating field: the fluid is supposed to be barotropic and nonlinear terms involving density fluctuations are neglected. The equations for the two-point two-time correlations are written. They are closed by extending the direct interaction approximation to (weakly) compressible fields. This work is then used as a ground to derive an extension of the eddy damped quasi-normal Markovian closure that accounts for compressibility effects. Both closures reflect the existence of acoustic waves and the complex nature of nonlinear interactions between modes. The EDQNM model is solved numerically for the case of an isotropic turbulent field maintained statistically stationary by injecting energy in the large scales. At low Mach number, the spectrum of the purely compressible velocity is found first to scale as K-5/3, then to evolve, at large time, towards an asymptotic K-11/3 scaling. The same behavior is found for the pressure spectrum, equipartition of energy between the two compressible modes being observed. Results concerning the dissipation show that its dilatational component is proportional to the square of the turbulent Mach number. At higher Mach number, the slope of the compressible spectra appears to be less steep, and discrepancies from the Mt2 scaling are detected. The influence of the Reynolds number is also analyzed and the ratio of the compressible energy to the solenoidal kinetic energy is found to scale as Mt2 Re for Mt2 Re smaller than 10. A simple spectral model reproducing the main features of the EDQNM results at low Mach number is proposed.

Bertoglio, Jean-Pierre; Bataille, Françoise; Marion, Jean-Denis

2001-01-01

382

Perceptual Image Compression in Telemedicine  

NASA Technical Reports Server (NTRS)

The next era of space exploration, especially the "Mission to Planet Earth" will generate immense quantities of image data. For example, the Earth Observing System (EOS) is expected to generate in excess of one terabyte/day. NASA confronts a major technical challenge in managing this great flow of imagery: in collection, pre-processing, transmission to earth, archiving, and distribution to scientists at remote locations. Expected requirements in most of these areas clearly exceed current technology. Part of the solution to this problem lies in efficient image compression techniques. For much of this imagery, the ultimate consumer is the human eye. In this case image compression should be designed to match the visual capacities of the human observer. We have developed three techniques for optimizing image compression for the human viewer. The first consists of a formula, developed jointly with IBM and based on psychophysical measurements, that computes a DCT quantization matrix for any specified combination of viewing distance, display resolution, and display brightness. This DCT quantization matrix is used in most recent standards for digital image compression (JPEG, MPEG, CCITT H.261). The second technique optimizes the DCT quantization matrix for each individual image, based on the contents of the image. This is accomplished by means of a model of visual sensitivity to compression artifacts. The third technique extends the first two techniques to the realm of wavelet compression. Together these two techniques will allow systematic perceptual optimization of image compression in NASA imaging systems. Many of the image management challenges faced by NASA are mirrored in the field of telemedicine. Here too there are severe demands for transmission and archiving of large image databases, and the imagery is ultimately used primarily by human observers, such as radiologists. In this presentation I will describe some of our preliminary explorations of the applications of our technology to the special problems of telemedicine.

Watson, Andrew B.; Ahumada, Albert J., Jr.; Eckstein, Miguel; Null, Cynthia H. (Technical Monitor)

1996-01-01

383

Gradient Compression Stockings may Prevent Recovery after Bed Rest Deconditioning  

NASA Technical Reports Server (NTRS)

Introduction: Astronauts continue to wear a compression garment during and immediately after landing to prevent orthostatic intolerance (OI). We recently developed a custom-fitted, 3-piece garment that consists of thigh-high stockings with biker-style shorts that provides continuous, gradient compression: 55 mmHg at the ankle that decreases to approximately 20 mmHg at the top of the leg and 15 mmHg over the abdomen. This garment has been shown to be effective in preventing symptoms of OI during a short stand test after Space Shuttle missions, but symptoms may persist for several days after a long-duration mission in some astronauts. The purpose of this study was to confirm the effectiveness of wearing these elastic, gradient compression garments during orthostatic testing after 2 weeks of 6 degree head-down tilt bed rest as a model of spaceflight and to determine whether they would impact recovery after bed rest. Methods: Eight (5 treatment, 3 control) of 16 subjects have completed this study to-date. All subjects wore the 3-piece garment from waking until tilt testing (3 h) as a simulation of the timeline for astronauts on landing day (BR+0). Control subjects removed the garment after the tilt test. Treatment subjects wore the garment for the remainder of the day and wore lower compression thigh-high only garments on the day after bed rest (BR+1). Blood pressure, heart rate, and stroke volume responses to a 15-min 80 degree head-up tilt test were determined before 2 weeks of 6 degree head-down tilt, and on BR+0 and BR+1. Plasma volume (PV) was measured before each of these test sessions. Data are mean SE. Results: Compression garments prevented signs of OI on BR+0; all subjects in both groups completed the full 15-min test. Heart rate responses to tilt were lower on BR+0 than all other test days. Control subjects demonstrated a marginal PV decrease after bed rest, but showed typical recovery the day after bed rest (BR+0: 2.32 plus or minus 0.15 L to BR+1: 2.79 plus or minus 0.15 L). Treatment subjects did not recover PV the day after bed rest (BR+0: 2.61 plus or minus 0.23 L to BR+1: 2.61 plus or minus 0.23 L). Conclusion: Abdomen-high compression garments, which are effective in preventing post-bed rest orthostatic intolerance, may slow recovery of PV. Modified garments with reduced compression may be necessary to prevent prolonging recovery.

Stenger, Michael B.; Lee, Stuart M.; Westby, Christian M.; Willig, Michael C.; Platts, Steven H.

2011-01-01

384

Compression of fingerprint data using the wavelet vector quantization image compression algorithm. 1992 progress report  

SciTech Connect

This report describes the development of a Wavelet Vector Quantization (WVQ) image compression algorithm for fingerprint raster files. The pertinent work was performed at Los Alamos National Laboratory for the Federal Bureau of Investigation. This document describes a previously-sent package of C-language source code, referred to as LAFPC, that performs the WVQ fingerprint compression and decompression tasks. The particulars of the WVQ algorithm and the associated design procedure are detailed elsewhere; the purpose of this document is to report the results of the design algorithm for the fingerprint application and to delineate the implementation issues that are incorporated in LAFPC. Special attention is paid to the computation of the wavelet transform, the fast search algorithm used for the VQ encoding, and the entropy coding procedure used in the transmission of the source symbols.

Bradley, J.N.; Brislawn, C.M.

1992-04-11

385

Restoring a Master Work  

NSDL National Science Digital Library

What does it take to restore a 350 year old painting? This site shows you! For ten weeks, conservators Joan Gorman and David Marquis worked on a painting by Italian painter Guercino during museum hours. That way, visitors got to see each stage in the restoration process. Click here to see for yourself.Please note: as of 07/06/2012, not all the links at this site were available.

Gorman, Joan

386

Compressive Sensing of Object-Signature  

Microsoft Academic Search

\\u000a Compressive sensing is a new framework for signal acquisition, compression, and processing. Of specific interest are two-dimensional\\u000a signals such as images where an optical unit performs the acquisition and compression (i.e., compressive sensing or compressive\\u000a imaging). The signal reconstruction and processing can be done by optical signal processing and\\/or digital signal processing.\\u000a In this paper we review the theoretical basis

Dan E. Tamir; Natan T. Shaked; Wilhelmus J. Geerts; Shlomi Dolev

387

Unusual self-similar spherical compression: theory and implementations  

NASA Astrophysics Data System (ADS)

We are showing a family of spherical implosions involving high compression rate. It depends on two parameters and we can work all of it out. I Theory What is an ``unusual self-similar compression law''? Such a law is characterized by a classical self-similar law initiated by a convergent shock (cf Lazarus and Richtmyer LA6823MS-1977) followed by centred compression waves. We will explain completely the implosion given by this law. II Implementations We will apply such a law to a DT sphere (m=1.5 mug and ?0=0.003 g/cm3). We will describe the thermodynamical conditions obtained this way. Then we will compare these results to those obtained with a 1D hydrodynamical computational code under different hypotheses regarding outside conditions and gas EOS. We will discuss the agreement between model and computational code under the different hypotheses. III Conclusion Such a flow may be worth using: -It gives an accurate hydrodynamical benchmark with the difficult problem of spherical shock convergence. -It can be used to define laser experiments where very compressed matter is needed (spectroscopy experiments, thermonuclear ignition...). Indeed, it allows to build an optimized compression law for each problem. An interesting extension of this work will be to add a second medium surrounding the gas. By using the characteristic curves, we could obtain the outside conditions (pressure or speed versus time) for this more realistic geometry.

Gerin-Roze, Jean

2005-07-01

388

Compressibility of floating pellets with verapamil hydrochloride coated with dispersion Kollicoat SR 30 D  

Microsoft Academic Search

The purpose of this study was to work out a method of compression of floating pellets with verapamil hydrochloride (VH) in a dose of 40mg. It was assumed that this form should reside in the stomach floating for several hours and gradually release the drug in a controlled way. Compression of pellets into tablets, being a modern technological process, is

Wies?aw Sawicki; Rafa? ?unio

2005-01-01

389

Parametric study of the influence of compression on the acoustical absorption coefficient of automotive felts  

Microsoft Academic Search

The present note describes some work related to the modelization of acoustical absorption properties of compressed porous materials. An `equivalent fluid' model with five parameters is used. This prediction technique is validated with some industrial materials being 1-D compressed along their thickness, starting from a felt mat having a given basic weight. The obtained results tend to indicate that an

Bernard Castagnède; Julian Tizianel; Alexei Moussatov; Achour Aknine; Bruno Brouard

2001-01-01

390

The application of fractal compression to content-based image retrieval: Comparison of methods  

Microsoft Academic Search

In this paper we will discuss the application of fractal compression concept in the field of content-based image retrieval. We will give a brief survey of the people's work that using fractal compressed code to retrieve images. In addition, an experiment that evaluates retrieval efficiency is given. Although their algorithms are slightly different from each other, the experiment results show

An-Zen Shih

2009-01-01

391

Longitudinal Control of Commercial Heavy Vehicles Equipped with Variable Compression Brake  

Microsoft Academic Search

In this report, we extend our previous work within MOU 372 on modeling and longitudinal speed control design for heavy commercial vehicles equipped with variable compression braking mechanisms. Previously, we developed a detailed crankangle based simulation model for a six cylinder, 350 hp diesel engine with a continuously varying compression brake that is capable of describing the intrinsic interactions between

Lasse Moklegaard; Maria Druzhinina; Anna G. Stefanopoulou

2002-01-01

392

Low-complexity and error-resilient hyperspectral image compression based on distributed source coding  

Microsoft Academic Search

In this paper we propose a lossless compression algorithm for hyperspectral images based on distributed source coding; this algorithm represents a significant improvement over our prior work on the same topic, and has been developed during a project funded by ESA-ESTEC. In particular, the algorithm achieves good compression performance with very low complexity; moreover, it also features a very good

A. Abrardo; M. Barni; A. Bertoli; A. Garzelli; E. Magli; F. Nencini; B. Penna; R. Vitulli

2008-01-01

393

Performance evaluation of functional medical imaging compression via optimal sampling schedule designs and cluster analysis  

Microsoft Academic Search

In previous work we have described a technique for the compression of positron emission tomography (PET) image data in the spatial and temporal domains based on optimal sampling schedule designs (OSS) and cluster analysis. It can potentially achieve a high data compression ratio greater than 80:1. However, the number of distinguishable cluster groups in dynamic PET image data is a

Zhe Chen; David Dagan Feng; Weidong Cai; Roger Fulton

2005-01-01

394

Impact of lossy compression on diagnostic accuracy of radiographs for periapical lesions  

NASA Technical Reports Server (NTRS)

OBJECTIVES: The purpose of this study was to evaluate the lossy Joint Photographic Experts Group compression for endodontic pretreatment digital radiographs. STUDY DESIGN: Fifty clinical charge-coupled device-based, digital radiographs depicting periapical areas were selected. Each image was compressed at 2, 4, 8, 16, 32, 48, and 64 compression ratios. One root per image was marked for examination. Images were randomized and viewed by four clinical observers under standardized viewing conditions. Each observer read the image set three times, with at least two weeks between each reading. Three pre-selected sites per image (mesial, distal, apical) were scored on a five-scale score confidence scale. A panel of three examiners scored the uncompressed images, with a consensus score for each site. The consensus score was used as the baseline for assessing the impact of lossy compression on the diagnostic values of images. The mean absolute error between consensus and observer scores was computed for each observer, site, and reading session. RESULTS: Balanced one-way analysis of variance for all observers indicated that for compression ratios 48 and 64, there was significant difference between mean absolute error of uncompressed and compressed images (P <.05). After converting the five-scale score to two-level diagnostic values, the diagnostic accuracy was strongly correlated (R (2) = 0.91) with the compression ratio. CONCLUSION: The results of this study suggest that high compression ratios can have a severe impact on the diagnostic quality of the digital radiographs for detection of periapical lesions.

Eraso, Francisco E.; Analoui, Mostafa; Watson, Andrew B.; Rebeschini, Regina

2002-01-01

395

Compressed natural gas fuel may be the future for Phoenix  

Microsoft Academic Search

It's the law: the future must include cleaner air, and alternative fuels for vehicular engines is one way to achieve it. In Phoenix, a city beset by moderate air quality problems, equipment managers of the Public Works Department's (PWD) fleet say their future seems to be with compressed natural gas (CNG). CNG fuels a pair of refuse packer trucks that

1994-01-01

396

Post-surgical thoracic pseudomeningocele causing spinal cord compression.  

PubMed

Pseudomeningoceles are extradural cerebrospinal fluid collections categorized into three groups: traumatic, congenital, and iatrogenic. Iatrogenic pseudomeningoceles occur after durotomy, usually after cervical or lumbar spine surgery. Although many remain asymptomatic, pseudomeningoceles can compress or herniate the spinal cord and nerve roots. We present a 57-year-old woman who had a thoracic laminectomy and discectomy. Two weeks after surgery, she presented with lower extremity weakness and gait difficulty. Physical examination revealed hyperreflexia and a T11 sensory level. MRI revealed a pseudomeningocele compressing the thoracic spinal cord. The patient underwent surgical drainage of the cyst. On follow-up, she had complete resolution of her symptoms, and MRI did not show a residual lesion. To our knowledge, this is the second documented post-operative pseudomeningocele causing symptomatic spinal cord compression of the thoracic spine. In this article, a review of the literature is presented, including four reported patients with post-traumatic pseudomeningocele causing myelopathic symptoms and 20 patients with iatrogenic pseudomeningocele that resulted in neurological decline due to herniation or compression of neural tissue. Treatment options for these lesions include conservative management, epidural blood patch, lumbar subarachnoid drainage, and lumbo-peritoneal shunt placement. Surgical repair, usually by primary dural closure, remains the definitive treatment modality for iatrogenic symptomatic pseudomeningoceles. PMID:24210805

Macki, Mohamed; Lo, Sheng-fu L; Bydon, Mohamad; Kaloostian, Paul; Bydon, Ali

2014-03-01

397

Vulnerability of the gradually elongated nerve to compression injury.  

PubMed

The purpose of this study is to clarify the vulnerability of the gradually elongated peripheral nerve. Rabbit's sciatic nerves were gradually elongated to 30 mm at the rate of 2.0 mm/day and 4.0 mm/day. Immediately after elongation, the sciatic nerve was exposed and compressed for 30 minutes at various forces, 15, 30 and 60 g/0.1 cm(2). Immediately after elongation and compression, 2, 4 and 8 weeks after compression, each group was electrophysiologically and histologically estimated--15 g/0.1 cm(2) caused no damage to the control group, neurapraxia to the 2.0 mm/day group, and axonotmesis to the 4.0 mm/day group; 30 g/0.1 cm(2) caused neurapraxia to the control group and axonotmesis to the 2.0 mm/day group; 60 g/0.1 cm(2) caused axonotmesis to the control group and slowly recovered axonotmesis to the 2.0 mm/day group. This study shows that though mild compression, does not cause nerve injury to the intact nerve, it can sometimes cause severe damage to the gradual elongated nerve. PMID:11677664

Ikeda, K; Yokoyama, M; Tomita, K; Tanaka, S

2001-07-01

398

Efficient access of compressed data  

SciTech Connect

A compression technique is presented that allows a high degree of compression but requires only logarithmic access time. The technique is a constant suppression scheme, and is most applicable to stable databases whose distribution of constants is fairly clustered. Furthermore, the repeated use of the technique permits the suppression of a multiple number of different constants. Of particular interest is the application of the constant suppression technique to databases the composite key of which is made up of an incomplete cross product of several attribute domains. The scheme for compressing the full cross product composite key is well known. This paper, however, also handles the general, incomplete case by applying the constant suppression technique in conjunction with a composite key suppression scheme.

Eggers, S.J.; Shoshani, A.

1980-06-01

399

Experimental compressive phase space tomography  

PubMed Central

Phase space tomography estimates correlation functions entirely from snapshots in the evolution of the wave function along a time or space variable. In contrast, traditional interferometric methods require measurement of multiple two–point correlations. However, as in every tomographic formulation, undersampling poses a severe limitation. Here we present the first, to our knowledge, experimental demonstration of compressive reconstruction of the classical optical correlation function, i.e. the mutual intensity function. Our compressive algorithm makes explicit use of the physically justifiable assumption of a low–entropy source (or state.) Since the source was directly accessible in our classical experiment, we were able to compare the compressive estimate of the mutual intensity to an independent ground–truth estimate from the van Cittert–Zernike theorem and verify substantial quantitative improvements in the reconstruction.

Tian, Lei; Lee, Justin; Oh, Se Baek; Barbastathis, George

2012-01-01

400

Millimeter-wave compressive holography.  

PubMed

We describe an active millimeter-wave holographic imaging system that uses compressive measurements for three-dimensional (3D) tomographic object estimation. Our system records a two-dimensional (2D) digitized Gabor hologram by translating a single pixel incoherent receiver. Two approaches for compressive measurement are undertaken: nonlinear inversion of a 2D Gabor hologram for 3D object estimation and nonlinear inversion of a randomly subsampled Gabor hologram for 3D object estimation. The object estimation algorithm minimizes a convex quadratic problem using total variation (TV) regularization for 3D object estimation. We compare object reconstructions using linear backpropagation and TV minimization, and we present simulated and experimental reconstructions from both compressive measurement strategies. In contrast with backpropagation, which estimates the 3D electromagnetic field, TV minimization estimates the 3D object that produces the field. Despite undersampling, range resolution is consistent with the extent of the 3D object band volume. PMID:20648123

Cull, Christy Fernandez; Wikner, David A; Mait, Joseph N; Mattheiss, Michael; Brady, David J

2010-07-01

401

Relations of Work Identity, Family Identity, Situational Demands, and Sex with Employee Work Hours  

ERIC Educational Resources Information Center

This study examined relations of multiple indicators of work identity and family identity with the number of weekly hours worked by 193 married business professionals. We found that men generally worked long hours regardless of the situational demands to work long hours and the strength of their work and family identities. Women's work hours, on…

Greenhaus, Jeffrey H.; Peng, Ann C.; Allen, Tammy D.

2012-01-01

402

Working on What Works: Working with Teachers to Improve Classroom Behaviour and Relationships  

ERIC Educational Resources Information Center

The Working on What Works (WOWW) approach, which is based upon Solution-focused Brief Therapy, was implemented in a mainstream primary classroom over a 10-week period. The focus was on improving behaviour and relationships in class. Results demonstrated an improvement in teacher ratings for targets set by the class teacher compared with baseline.…

Brown, Emma L.; Powell, Emma; Clark, Adele

2012-01-01

403

Data compression for satellite images  

NASA Technical Reports Server (NTRS)

An efficient data compression system is presented for satellite pictures and two grey level pictures derived from satellite pictures. The compression techniques take advantages of the correlation between adjacent picture elements. Several source coding methods are investigated. Double delta coding is presented and shown to be the most efficient. Both predictive differential quantizing technique and double delta coding can be significantly improved by applying a background skipping technique. An extension code is constructed. This code requires very little storage space and operates efficiently. Simulation results are presented for various coding schemes and source codes.

Chen, P. H.; Wintz, P. A.

1976-01-01

404

Divided-pulse nonlinear compression  

NASA Astrophysics Data System (ADS)

Passive spatial and temporal coherent combining schemes are implemented to scale the output energy of a nonlinear temporal compression setup. By generating 32 replicas of the incident femtosecond pulses, the output of a high energy fiber chirped-pulse amplifier can be compressed using self-phase modulation in a large mode area rod-type fiber at peak power levels well beyond the self-focusing threshold of 4 MW. We demonstrate the generation of 71 fs 7.5 ?J pulses at 100 kHz repetition rate, corresponding to a peak power of 86 MW.

Guichard, Florent; Zaouter, Yoann; Hanna, Marc; Druon, Frédéric; Mottay, Eric; Georges, Patrick

2014-03-01

405

Data compression in digitized lines  

SciTech Connect

The problem of data compression is very important in digital photogrammetry, computer assisted cartography, and GIS/LIS. In addition, it is also applicable in many other fields such as computer vision, image processing, pattern recognition, and artificial intelligence. Consequently, there are many algorithms available to solve this problem but none of them are considered to be satisfactory. In this paper, a new method of finding critical points in a digitized curve is explained. This technique, based on the normalized symmetric scattered matrix, is good for both critical points detection and data compression. In addition, the critical points detected by this algorithm are compared with those by zero-crossings. 8 refs.

Thapa, K. (Ferris State Univ., Big Rapids, MI (USA))

1990-04-01

406

Data compression in digitized lines  

NASA Technical Reports Server (NTRS)

The problem of data compression is very important in digital photogrammetry, computer assisted cartography, and GIS/LIS. In addition, it is also applicable in many other fields such as computer vision, image processing, pattern recognition, and artificial intelligence. Consequently, there are many algorithms available to solve this problem but none of them are considered to be satisfactory. In this paper, a new method of finding critical points in a digitized curve is explained. This technique, based on the normalized symmetric scattered matrix, is good for both critical points detection and data compression. In addition, the critical points detected by this algorithm are compared with those by zero-crossings.

Thapa, Khagendra

1990-01-01

407

Ammonium azide under hydrostatic compression  

NASA Astrophysics Data System (ADS)

The properties of ammonium azide NH4N3 upon compression were investigated using first-principles density functional theory. The equation of state was calculated and the mechanism of a phase transition experimentally observed at 3.3 GPa is elucidated. Novel polymorphs of NH4N3 were found using a simple structure search algorithm employing random atomic displacements upon static compression. The structures of three new polymorphs, labelled as B, C, and D, are similar to those of other metal azides.

Landerville, A. C.; Steele, B. A.; Oleynik, I. I.

2014-05-01

408

Phase transition during uniaxial compression  

NASA Astrophysics Data System (ADS)

An experimental study was conducted to investigate the possibility of a first-order isostructural phase transition during the uniaxial compression of single crystals of Sm(1-x)Gd(x)S solid solutions (x = 0.15). The compression of the samples was carried out along the longest dimension corresponding to the 100 crystallographic direction. A change in the color of samples from black to golden yellow and a discontinuity in electrical conductivity were observed. When the pressure was removed the inverse transition did not occur.

Kaminskii, V. V.; Vinogradov, A. A.; Stepanov, N. N.; Smirnov, I. A.

1983-05-01

409

Flux compression generators as plasma compression power sources  

Microsoft Academic Search

A survey is made of applications where explosive-driven magnetic flux compression generators are used to directly power devices that produce dense plasmas. Representative examples are discussed that are specific to the theta pinch, the plasma gun, the dense plasma focus, and the Z pinch in order to illustrate the high energy and power capabilities of explosive generators. An application employing

C. M. Fowler; R. S. Caird; D. J. Erickson; B. L. Freeman; W. B. Garn

1979-01-01

410

The CCSDS Lossless Data Compression Algorithm for Space Applications  

NASA Technical Reports Server (NTRS)

In the late 80's, when the author started working at the Goddard Space Flight Center (GSFC) for the National Aeronautics and Space Administration (NASA), several scientists there were in the process of formulating the next generation of Earth viewing science instruments, the Moderate Resolution Imaging Spectroradiometer (MODIS). The instrument would have over thirty spectral bands and would transmit enormous data through the communications channel. This was when the author was assigned the task of investigating lossless compression algorithms for space implementation to compress science data in order to reduce the requirement on bandwidth and storage.

Yeh, Pen-Shu; Day, John H. (Technical Monitor)

2001-01-01

411

Large-eddy simulation of magnetohydrodynamic turbulence in compressible fluid  

SciTech Connect

In the present article, the large eddy simulation (LES) technique for the study of compressible magnetohydrodynamic turbulence is developed. The filtered equations of magnetohydrodynamics of compressible fluid are obtained with the use of a mass-weighted filtering procedure (Favre filtering). Favre-filtered equations for large-scale components of turbulence include subgrid-scale terms describing subgrid phenomena. Different models for closure of subgrid terms are suggested. In this work numerical simulation of filtered magnetohydrodynamic equations and an analysis of the received characteristics of turbulent flow is carried out. The obtained results of numerical computations for different LES models are compared with the results of direct numerical simulation.

Chernyshov, A.A.; Karelsky, K.V.; Petrosyan, A.S. [Theoretical Section, Space Research Institute of Russian Academy of Sciences, Profsoyuznaya 84/32, 117997, Moscow (Russian Federation)

2006-03-15

412

Studies of fiber-matrix adhesion on compression strength  

NASA Technical Reports Server (NTRS)

A study was initiated on the effect of the matrix polymer and the fiber matrix bond strength of carbon fiber polymer matrix composites. The work includes tests with micro-composites, single ply composites, laminates, and multi-axial loaded cylinders. The results obtained thus far indicate that weak fiber-matrix adhesion dramatically reduces 0 degree compression strength. Evidence is also presented that the flaws in the carbon fiber that govern compression strength differ from those that determine fiber tensile strength. Examination of post-failure damage in the single ply tests indicates kink banding at the crack tip.

Bascom, Willard D.; Nairn, John A.; Boll, D. J.

1991-01-01

413

Compressive properties and function–composition relationships of developing bovine articular cartilage  

Microsoft Academic Search

The composition of cartilage is known to change during fetal and postnatal development. The objectives of this study were to characterize the compressive biomechanical properties of the 1 mm thick articular layer of cartilage of the distal femur from third-trimester bovine fetuses, from 1 to 3 week old bovine calf and from young adult bovine knees, and to correlate these

Amanda K. Williamson; Albert C. Chen; Robert L. Sah

2001-01-01

414

INITIAL TREATMENT OF CLOSED METACARPAL FRACTURES: A controlled comparison of compression glove and splintage  

Microsoft Academic Search

A prospective clinical trial compared two forms of initial management for closed stable fractures of the shaft of the finger metacarpals. Patients were randomized to treatment with a compression glove and early mobilization (21 patients) or to immobilization in a plaster splint (21 patients).The mean loss of total active flexion (MP + PIP + DIP) in the second week after

P. J. McMAHON; D. A. WOODS; P. D. BURGE

1994-01-01

415

Joint Eglin Acoustic Week III Data Report  

NASA Technical Reports Server (NTRS)

A series of three flight tests have been conducted at an Eglin Air Force Base remote test range located in the Florida panhandle. The first was the "Acoustics Week" flight test conducted in September 2003. The second was the NASA Heavy Lift Rotorcraft Acoustic Flight Test conducted in October-November 2005. The most recent was the Eglin Acoustic Week III test conducted in August-September 2007. This series of tests acquired acoustic data for a number of rotary and fixed wing aircraft and are used to generate noise semi-spheres used in predicting the acoustic footprint for prescribed flight operations. This extensive database can be used to determine the impact of flight operations on communities around a terminal area as well as for prediction code validations. Another valuable use of the semi-spheres is determining the long-range propagation of noise for civilian and military purposes. This paper describes the third test in this series. Data described in this report were acquired during testing of the MD-902 and Mi-8M aircraft. In addition, data acquired during a set of atmospheric propagation tests is also described.

Watts, Michael E.; Conner, David A.; Smith, Charles D.

2010-01-01

416

Genetic diagnosis before the eighth gestational week.  

PubMed

Transabdominal chorionic villus sampling (CVS) by a freehand, ultrasound-guided technique was offered to 210 high-genetic-risk women at 6-7 weeks' gestation. It was carried out in 201 cases and postponed in nine cases (4.3%). Sampling was successful in 86 and 100% of cases after the first and the second needle insertions, respectively. Chorionic tissue specimens weighed at least 20 mg in 86% of cases, and only 2% were below 10 mg. Early complications were present in 7.9% of cases, apparently without any adverse effect on maternal or fetal outcome. The rate of fetal loss was 3.5%. Genetic diagnosis was concluded in 1-3 days by rapid diagnostic methods. Although more extensive laboratory and clinical experience is necessary to evaluate adequately the safety of early transabdominal CVS, it may be advantageous to offer this technique to certain high-genetic-risk patients. The availability of genetic diagnosis before the eighth week makes clinical abortion by antiprogestins and prostaglandins a viable option in cases of affected embryos. PMID:1988902

Brambati, B; Tului, L; Simoni, G; Travi, M

1991-02-01

417

NJ Teachers Back to Work  

NSDL National Science Digital Library

Middletown, New Jersey schoolteachers went back to work today after a labor dispute that landed a quarter of the teaching work force in jail. The teachers had staged a walk-out because they refused to continue working without a new contract (the old one had expired on June 30), and they resisted proposed increases in their health insurance premiums. Last week, Judge Clarkson S. Fisher Jr. issued a back-to-work order, and when the striking teachers failed to follow the order, he began jailing them, working his way through the alphabet day by day. By yesterday, more than 225 teachers were in jail. Today, the teachers agreed to go back to work next week, and the union and the school district will enter non-binding mediation.

Koplow, Travis.

2001-01-01

418

Effective compression bandage for repair of a complicated radial artery pseudoaneurysm.  

PubMed

We describe a 10-week-old hemophilic infant who developed a large-sized pseudoaneurysm of the radial artery after arterial puncture. Based on our previous experience, compression bandage was elected as first-line treatment. The clinical course was complicated by skin ulceration. However, compression bandage was continued, and complete thrombosis of the pseudoaneurysm occurred after 4 weeks of treatment, preserving arterial patency. Bedside clot evacuation and enzymatic debridement promoted rapid wound healing with negligible scar formation. Compression bandage is a safe and valuable measure for repair of radial artery pseudoaneurysm, even in patients with clotting disorders. Professionals are encouraged to consider the benefit of such an artery-sparing treatment option. PMID:24456862

Ceccanti, Silvia; Frediani, Simone; Andreoli, Gian Marco; Giannini, Luigi; Ferro, Rosalia; Cozzi, Denis A

2014-07-01

419

The compressibility burble and the effect of compressibility on pressures and forces acting on a airfoil  

NASA Technical Reports Server (NTRS)

Simultaneous air-flow photographs and pressure-distribution measurements were made of the NACA 4412 airfoil at high speeds to determine the physical nature of the compressibility burble. The tests were conducted in the NACA 24-inch high-speed wind tunnel. The flow photographs were obtained by the Schlieren method and the pressures were simultaneously measured for 54 stations in the 5-inch-chord airfoil by means of a multiple-tube manometer. Following the general program, a few measurements of total-pressure loss in the wake of the airfoil at high speeds were made to illustrate the magnitude of the losses involved and the extent of the disturbed region; and, finally, in order to relate this work to earlier force-test data, a force test of a 5-inch-chord NACA 4412 airfoil was made. The results show the general nature of the phenomenon known as the compressibility burble. The source of the increased drag is shown to be a compression shock that occurs on the airfoil as its speed approaches the speed of sound. Finally, it is indicated that considerable experimentation is needed in order to understand the phenomenon completely.

Stack, John; Lindsey, W F; Littell, Robert E

1939-01-01

420

Laparotomic Myomectomy in the 16th Week of Pregnancy: A Case Report  

PubMed Central

Myomectomy is rarely performed during an ongoing pregnancy because of fear of miscarriage and the risk of an uncontrolled haemorrhage necessitating a hysterectomy. In cases where myomectomy is undertaken, most are performed at the time of cesarean section or with a laparoscopic approach. We report a case of a successful laparotomic myomectomy in the 16th week of pregnancy. A 35-year-old primigravida was admitted to our department with acute abdominal pain and hydronephrosis (serum creatinine 1.6?mg/dL). Imaging revealed a large implant myoma compressing the bladder, ureters, rectus, and gestational chamber and causing hydronephrosis. Laparotomic myomectomy was successfully performed and pregnancy continued uneventfully until the 38th week when a cesarean section was performed. Surgical management of myomas during pregnancy is worth evaluating in well-selected and highly symptomatic cases.

Di Donato, Violante; Gasparri, Maria Luisa; Lecce, Francesca; Caccetta, Jlenia; Panici, Pierluigi Benedetti

2014-01-01

421

Video compression with parallel processing  

Microsoft Academic Search

Driven by the rapidly increasing demand for audio-visual applications, digital video com- pression technology has become a mature field, offering several available products based on both hardware and software implementations. Taking advantage of spatial, temporal, and sta- tistical redundancies in video data, a video compression system aims to maximize the compres- sion ratio while maintaining a high picture quality. Despite

Ishfaq Ahmad; Yong He; Ming L. Liou

2002-01-01

422

Transposed compression piston and cylinder  

Microsoft Academic Search

This patent describes an improved V-type two piston Stirling engine wherein the improvement is a transposed compression piston slidably engaged in a mating cylinder. It comprises: a cylindrical body which is pivotally connected to a connecting rod at a pivot axis which is relatively nearer the outer end of the cylindrical body and has a seal relatively nearer the inner

1992-01-01

423

SAR Image Compression Using Steganography  

Microsoft Academic Search

Steganograhy is generally used to hide important information in a visible media mostly an image or video. In this paper, a novel scheme serving the dual purpose of concealing and compressing Synthetic Aperture Radar (SAR) images using steganography technique is proposed for aerospace and satellite applications. SAR images represent an important source of information for a large variety of applications

M. Jayachandran; J. Manikandan

2010-01-01

424

Group Testing for Image Compression  

Microsoft Academic Search

This paper presents the Group Testing for Wavelets algorithm (GTW), which is a novel embedded wavelet-based image compression technique based on the concept of group testing. We explain how group testing is a generalization of the zerotree coding technique for wavelet-transformed images. We also show that Golomb coding is equivalent to Hwang's group testing algorithm [3]. GTW is similar to

Edwin S. Hong; Richard E. Ladner

2000-01-01

425

Diocotron spectrum with compression effects  

Microsoft Academic Search

The diocotron spectrum for a simplified model of Malmberg-Penning traps that includes compression effects due to end curvature is investigated herein. Performing an initial value treatment, we find that there is a class of length profiles for which the linearized eigenvalue equation of the model can be integrated in quadratures (integrable case). In this case, there is only algebraic growth

G. L. Delzanno; V. I. Pariev; G. Lapenta; J. M. Finn

2002-01-01

426

Diocotron Spectrum with Compression Effects.  

National Technical Information Service (NTIS)

The diocotron spectrum for a simplified model of Malmberg-Penning traps that includes compression effects due to end curvature is investigated herein. Performing an initial value treatment, we find that there is a class of length profiles for which the li...

G. Lapenta G. L. Delzanno J. M. Finn V. I. Pariev

2002-01-01

427

Diocotron spectrum with compression effects  

Microsoft Academic Search

The diocotron spectrum for a simplified model of Malmberg-Penning traps that includes compression effects due to end curvature is investigated herein. Performing an initial value treatment, we find that there is a class of length profiles for which the linearized eigenvalue equation of the model can be integrated in quadratures (integrable case). In this case, there is only algebraic growth

G. L. Delzanno; V. I. Pariev; G. M. Lapenta; J. M. Finn

2001-01-01

428

Bandelet Image Approximation and Compression  

Microsoft Academic Search

Finding ecien t geometric representations of images is a central issue to improve image compression and noise removal algorithms. We introduce bandelet orthogonal bases and frames that are adapted to the geometric regularity of an image. Images are approximated by nding a best bandelet basis or frame that produces a sparse representation. For functions that are uniformly regular outside a

E. Le Pennec; S. Mallat

2005-01-01

429

Compressive genomics for protein databases  

PubMed Central

Motivation: The exponential growth of protein sequence databases has increasingly made the fundamental question of searching for homologs a computational bottleneck. The amount of unique data, however, is not growing nearly as fast; we can exploit this fact to greatly accelerate homology search. Acceleration of programs in the popular PSI/DELTA-BLAST family of tools will not only speed-up homology search directly but also the huge collection of other current programs that primarily interact with large protein databases via precisely these tools. Results: We introduce a suite of homology search tools, powered by compressively accelerated protein BLAST (CaBLASTP), which are significantly faster than and comparably accurate with all known state-of-the-art tools, including HHblits, DELTA-BLAST and PSI-BLAST. Further, our tools are implemented in a manner that allows direct substitution into existing analysis pipelines. The key idea is that we introduce a local similarity-based compression scheme that allows us to operate directly on the compressed data. Importantly, CaBLASTP’s runtime scales almost linearly in the amount of unique data, as opposed to current BLASTP variants, which scale linearly in the size of the full protein database being searched. Our compressive algorithms will speed-up many tasks, such as protein structure prediction and orthology mapping, which rely heavily on homology search. Availability: CaBLASTP is available under the GNU Public License at http://cablastp.csail.mit.edu/ Contact: bab@mit.edu

Daniels, Noah M.; Gallant, Andrew; Peng, Jian; Cowen, Lenore J.; Baym, Michael; Berger, Bonnie

2013-01-01

430

A programmable image compression system  

NASA Technical Reports Server (NTRS)

A programmable image compression system which has the necessary flexibility to address diverse imaging needs is described. It can compress and expand single frame video images (monochrome or color) as well as documents and graphics (black and white or color) for archival or transmission applications. Through software control, the compression mode can be set for lossless or controlled quality coding; the image size and bit depth can be varied; and the image source and destination devices can be readily changed. Despite the large combination of image data types, image sources, and algorithms, the system provides a simple consistent interface to the programmer. This system (OPTIPAC) is based on the TITMS320C25 digital signal processing (DSP) chip and has been implemented as a co-processor board for an IBM PC-AT compatible computer. The underlying philosophy can readily be applied to different hardware platforms. By using multiple DSP chips or incorporating algorithm specific chips, the compression and expansion times can be significantly reduced to meet performance requirements.

Farrelle, Paul M.

1989-01-01

431

Envera Variable Compression Ratio Engine  

Microsoft Academic Search

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

Charles Mendler

2011-01-01

432

Lightness compression and hue changes.  

PubMed

Two experiments were performed to relate the Bezold-Brücke (B-B) and lightness compression effects. The first used a calibrated screen to present an achromatic luminance staircase. In addition, it reproduced, the methodology and the essential aspects the lightness compression effect discovered by Cataliotti and Gilchrist (1995). That is, observers perceived a truncated grey scale (from white to medium grey) when the staircase was the only stimulation in the near background (Gelb condition), but not when presented on a Mondrian background, because of the high articulation level provided by this background. Experiment 1 design also included two other backgrounds that produced a partial compression effect. In Experiment 2, two chromatic staircases were used. Employing a naming task, changes in hue perception were only observed for the susceptible staircase. The observed changes were of two types. First, for the full staircase presentations, a Gelb background produced maximum lightness compression (more similarity in the lightness of the staircase stimuli) and, also, a minimum B-B effect (fewer differences in hue). Second, only for the Gelb condition, there were changes in the hue of the lowest luminance staircase stimuli depending on the staircase extension. Results are discussed in the framework of the anchoring theory of lightness perception. PMID:17120709

Lillo, Julio; Moreira, Humberto

2006-11-01

433

COMPRESSIBLE FLOW, ENTRAINMENT, AND MEGAPLUME  

EPA Science Inventory

It is generally believed that low Mach number, i.e., low-velocity, flow may be assumed to be incompressible flow. Under steady-state conditions, an exact equation of continuity may then be used to show that such flow is non-divergent. However, a rigorous, compressible fluid-dynam...

434

Wavelet Transform Image Compression Prototype  

Microsoft Academic Search

In this study, we seek to develop a low power, area efficient wavelet compression chip capable of reconstructing sharp images at acceptable noise levels. It can be used in conjunction with such devices as the 256 x 256 CMOS Active Pixel Sensor (APS) camera under developed at JPL (1), or because of its small size, incorporated on the image sensor

Lanier Watkins; Kenneth R. Perry; John S. Hurley; J. P. Brawley; B. Olson; B. Pain

435

Compressibility and Polymorphism of Solids.  

National Technical Information Service (NTIS)

The compressibility of solids is expressed in terms of fundamental physical quantities in relation to the energy of an electron in the L-shell orbital. When the concept of 'apparent valency' z sub a = (rho)z, the product of classical valency (z) and the r...

J. N. Plendl P. J. M. Gielisse

1969-01-01

436

Compressive holography of diffuse objects.  

PubMed

We propose an estimation-theoretic approach to the inference of an incoherent 3D scattering density from 2D scattered speckle field measurements. The object density is derived from the covariance of the speckle field. The inference is performed by a constrained optimization technique inspired by compressive sensing theory. Experimental results demonstrate and verify the performance of our estimates. PMID:21124522

Choi, Kerkil; Horisaki, Ryoichi; Hahn, Joonku; Lim, Sehoon; Marks, Daniel L; Schulz, Timothy J; Brady, David J

2010-12-01

437

Hyperspectral image compressive projection algorithm  

NASA Astrophysics Data System (ADS)

We describe a compressive projection algorithm and experimentally assess its performance when used with a Hyperspectral Image Projector (HIP). The HIP is being developed by NIST for system-level performance testing of hyperspectral and multispectral imagers. It projects a two-dimensional image into the unit under test (UUT), whereby each pixel can have an independently programmable arbitrary spectrum. To efficiently project a single frame of dynamic realistic hyperspectral imagery through the collimator into the UUT, a compression algorithm has been developed whereby the series of abundance images and corresponding endmember spectra that comprise the image cube of that frame are first computed using an automated endmember-finding algorithm such as the Sequential Maximum Angle Convex Cone (SMACC) endmember model. Then these endmember spectra are projected sequentially on the HIP spectral engine in sync with the projection of the abundance images on the HIP spatial engine, during the singleframe exposure time of the UUT. The integrated spatial image captured by the UUT is the endmember-weighted sum of the abundance images, which results in the formation of a datacube for that frame. Compressive projection enables a much smaller set of broadband spectra to be projected than monochromatic projection, and thus utilizes the inherent multiplex advantage of the HIP spectral engine. As a result, radiometric brightness and projection frame rate are enhanced. In this paper, we use a visible breadboard HIP to experimentally assess the compressive projection algorithm performance.

Rice, Joseph P.; Allen, David W.

2009-05-01

438

Hyperspectral image compressive projection algorithm  

Microsoft Academic Search

We describe a compressive projection algorithm and experimentally assess its performance when used with a Hyperspectral Image Projector (HIP). The HIP is being developed by NIST for system-level performance testing of hyperspectral and multispectral imagers. It projects a two-dimensional image into the unit under test (UUT), whereby each pixel can have an independently programmable arbitrary spectrum. To efficiently project a

Joseph P. Rice; David W. Allen

2009-01-01

439

Device Assists Cardiac Chest Compression  

NASA Technical Reports Server (NTRS)

Portable device facilitates effective and prolonged cardiac resuscitation by chest compression. Developed originally for use in absence of gravitation, also useful in terrestrial environments and situations (confined spaces, water rescue, medical transport) not conducive to standard manual cardiopulmonary resuscitation (CPR) techniques.

Eichstadt, Frank T.

1995-01-01

440

Tension-Compression Testing Machine.  

National Technical Information Service (NTIS)

The machine applies either tensile of compressive loads through a single head movable at high speeds. The head of the testing machine is drawn by a piston which is pressurized on one side by an expandable gas and on the other side by a rather incompressib...

J. M. Krafft J. C. Hahn

1965-01-01

441

Thermodynamic Properties of Compressed Gases.  

National Technical Information Service (NTIS)

The purpose of the project is to provide reliable values for the thermodynamic properties of 'key' compressed gaseous systems which can be used as points of reference for a better understanding of the laws of mixing. For several reasons the binary system,...

R. H. Harrison R. T. Moore D. R. Douslin

1966-01-01

442

Stability evaluation of the Markel Mine at Weeks Island, Louisiana  

SciTech Connect

A three dimensional (3D) finite element analysis of the Markel Mine located on Weeks Island was performed to: (1) evaluate the stability of the mine and (2) determine the effect of mine failure on the nearby Morton Salt mine and SPR facilities. The first part of the stability evaluation investigates the effect of pillar failure on mine stability. These simulations revealed that tensile stresses and dilatant damage develop in the overlying salt as a result of pillar loss. These tensile stresses extend to the salt/overburden interface only for the case where all 45 of the pillars are assumed to fail. Tensile stresses would likely cause microfracturing of the salt, resulting in a flow path for groundwater from the overlying aquifer to enter the mine. The dilatant damage bridges between the mine and the overburden in the case where 15 or more pillars are removed from the model. Dilatant damage is attributed to microfracturing or changes in the pore structure of the salt and could also result in a flow path for groundwater to enter the mine. The second part of the Markel Mine evaluation investigates the stability of the pillars with respect to three failure mechanisms: tensile failure, compressive failure, and creep rupture. A 3D slabbing pillar model of the Markel mine was developed to investigate progressive failure of the pillars and the effect of slabbing on mine stability. Based on a strain-limiting creep rupture criterion, pillar failure is predicted to be extensive at present. The associated loss of pillar strength should be equivalent to removing all pillars from the model as was done in the first part of this stability analysis, resulting in the possibility of ground water intrusion. Since creep rupture is not a well understood phenomenon, further development and validation of this criterion is recommended.

Hoffman, E.L.

1994-06-01

443

The CCDS Data Compression Recommendations: Development and Status  

NASA Technical Reports Server (NTRS)

The Consultative Committee for Space Data Systems (CCSDS) has been engaging in recommending data compression standards for space applications. The first effort focused on a lossless scheme that was adopted in 1997. Since then, space missions benefiting from this recommendation range from deep space probes to near Earth observatories. The cost savings result not only from reduced onboard storage and reduced bandwidth, but also in ground archive of mission data. In many instances, this recommendation also enables more science data to be collected for added scientific value. Since 1998, the compression sub-panel of CCSDS has been investigating lossy image compression schemes and is currently working towards a common solution for a single recommendation. The recommendation will fulfill the requirements for remote sensing conducted on space platforms.

Yeh, Pen-Shu; Moury, Gilles; Armbruster, Philippe; Day, John H. (Technical Monitor)

2002-01-01

444

General Equation Set Solver for Compressible and Incompressible Turbomachinery Flows  

NASA Technical Reports Server (NTRS)

Turbomachines for propulsion applications operate with many different working fluids and flow conditions. The flow may be incompressible, such as in the liquid hydrogen pump in a rocket engine, or supersonic, such as in the turbine which may drive the hydrogen pump. Separate codes have traditionally been used for incompressible and compressible flow solvers. The General Equation Set (GES) method can be used to solve both incompressible and compressible flows, and it is not restricted to perfect gases, as are many compressible-flow turbomachinery solvers. An unsteady GES turbomachinery flow solver has been developed and applied to both air and water flows through turbines. It has been shown to be an excellent alternative to maintaining two separate codes.

Sondak, Douglas L.; Dorney, Daniel J.

2002-01-01

445

Compressive Sensing: Analysis of Signals in Radio Astronomy  

NASA Astrophysics Data System (ADS)

The compressive sensing (CS) theory says that for some kind of signals there is no need to keep or transfer all the data acquired accordingly to the Nyquist criterion. In this work we investigate if the CS approach is applicable for recording and analysis of radio astronomy (RA) signals. Since CS methods are applicable for the signals with sparse (and compressible) representations, the compressibility of RA signals is verified. As a result, we identify which RA signals can be processed using CS, find the parameters which can improve or degrade CS application to RA results, describe the optimum way how to perform signal filtering in CS applications. Also, a range of virtual LabVIEW instruments are created for the signal analysis with the CS theory.

Gaigals, G.; Greit?ns, M.; Andziulis, A.

446

URe2-A compressibility study of allotropic phases  

NASA Astrophysics Data System (ADS)

URe2 compound exists in two phases- orthorhombic and hexagonal. The hexagonal phase has been prepared using arc melting and annealingat 500°C for one week, whereas the orthorhombic phase was achieved by annealing the arc melted sample at a temperature 150°C for the same period. High pressure x-ray diffraction studies on these two allotropic forms of URe2 have been carried out up to ˜15GPa using a diamond anvil cell. Normal compression was observed without any kind of phase transformation; although there is a probability of transformation from the metastable hexagonal to itsstable orthorhombicphase under pressure.

Shukla, B.; Shekar, N. V. Chandra; Sahu, P. Ch.

2014-04-01

447

75 FR 71005 - American Education Week, 2010  

Federal Register 2010, 2011, 2012, 2013

...standard and quality of education that we establish for...continue to invest in education at all levels, work with States...dreams when teachers, parents, and communities support...insist upon excellence. Education has always been...

2010-11-22

448

Volatile Emissions from Compressed Tissue  

PubMed Central

Since almost every fifth patient treated in hospital care develops pressure ulcers, early identification of risk is important. A non-invasive method for the elucidation of endogenous biomarkers related to pressure ulcers could be an excellent tool for this purpose. We therefore found it of interest to determine if there is a difference in the emissions of volatiles from compressed and uncompressed tissue. The ultimate goal is to find a non-invasive method to obtain an early warning for the risk of developing pressure ulcers for bed-ridden persons. Chemical analysis of the emissions, collected in compresses, was made with gas-chromatography – mass spectrometry and with a chemical sensor array, the so called electronic nose. It was found that the emissions from healthy and hospitalized persons differed significantly irrespective of the site. Within each group there was a clear difference between the compressed and uncompressed site. Peaks that could be certainly deemed as markers of the compression were, however, not identified. Nonetheless, different compounds connected to the application of local mechanical pressure were found. The results obtained with GC-MS reveal the complexity of VOC composition, thus an array of non-selective chemical sensors seems to be a suitable choice for the analysis of skin emission from compressed tissues; it may represent a practical instrument for bed side diagnostics. Results show that the adopted electronic noses are likely sensitive to the total amount of the emission rather than to its composition. The development of a gas sensor-based device requires then the design of sensor receptors adequate to detect the VOCs bouquet typical of pressure. This preliminary experiment evidences the necessity of studies where each given person is followed for a long time in a ward in order to detect the insurgence of specific VOCs pattern changes signalling the occurrence of ulcers.

Dini, Francesca; Capuano, Rosamaria; Strand, Tillan; Ek, Anna-Christina; Lindgren, Margareta; Paolesse, Roberto; Di Natale, Corrado; Lundstrom, Ingemar

2013-01-01

449

Pathology Case Study: Two Weeks in Africa  

NSDL National Science Digital Library

The University of Pittsburgh School of MedicineâÂÂs Department of Pathology has compiled a series of case studies to help both students and instructors. In this clinical microbiology case, a 16-year-old male developed symptoms of fatigue, diarrhea, nausea, and vomiting after returning to the United States from a two-week trip to Sudan. Laboratory test results and information from a microscopic examination are included in the case study. Clicking on the âÂÂFinal Diagnosisâ section will take you to a detailed discussion of the patientâÂÂs condition from the contributing doctor. A list of references, which students could use to get more background information, is also included at the bottom of the section.

Contis, Lydia C.; Qu, Lirong

2009-02-10

450

Atmospheric Electric Field of Lisbon (Portugal) affected by the week urban pollution cycle  

NASA Astrophysics Data System (ADS)

Atmospheric electric field was recorded at Portela meteorological station (Lisbon, Portal) in the period from 1955 to 1991. Using the Lomb-Scargle strategy to calculate the spectral record of the atmospheric electric field a clear evidence of the existence of a weekly cycle is found. Additionally, this cycle becomes more significant in the last years of the time-series. To further confirm this finding we performed a simple statistical approach that showed consistency with the spectral analysis. Two datasets were considered: (i) all days in the period, and (ii) fair-weather days only. The weekly cycle was attributed to urban pollution that has a weekly cycle (working days produce more pollutants than non-working days) while there is no other meteorological mechanism imposing such periodicity. Finally, the growing significance of the weekly cycle over the years is attributed to an increase in urban activity, namely motorway traffic in Lisbon.

Gonçalves da Silva, Hugo; Conceição, Ricardo; Melgão, Marta; Mendes, Paula; Tlemçani, Mouhaydine; Serrano, Claudia; Reis, António H.

2014-05-01

451

2012 ARPA-E Energy Innovation Summit: Profiling General Compression: A River of Wind  

ScienceCinema

The third annual ARPA-E Energy Innovation Summit was held in Washington D.C. in February, 2012. The event brought together key players from across the energy ecosystem - researchers, entrepreneurs, investors, corporate executives, and government officials - to share ideas for developing and deploying the next generation of energy technologies. A few videos were selected for showing during the Summit to attendees. These 'performer videos' highlight innovative research that is ongoing and related to the main topics of the Summit's sessions. Featured in this video are David Marcus, Founder of General Compression, and Eric Ingersoll, CEO of General Compression. General Compression, with the help of ARPA-E funding, has created an advanced air compression process which can store and release more than a weeks worth of the energy generated by wind turbines.

Marcus, David; Ingersoll, Eric

2012-03-21

452

2012 ARPA-E Energy Innovation Summit: Profiling General Compression: A River of Wind  

SciTech Connect

The third annual ARPA-E Energy Innovation Summit was held in Washington D.C. in February, 2012. The event brought together key players from across the energy ecosystem - researchers, entrepreneurs, investors, corporate executives, and government officials - to share ideas for developing and deploying the next generation of energy technologies. A few videos were selected for showing during the Summit to attendees. These 'performer videos' highlight innovative research that is ongoing and related to the main topics of the Summit's sessions. Featured in this video are David Marcus, Founder of General Compression, and Eric Ingersoll, CEO of General Compression. General Compression, with the help of ARPA-E funding, has created an advanced air compression process which can store and release more than a weeks worth of the energy generated by wind turbines.

Marcus, David; Ingersoll, Eric

2012-02-29

453

Genetic amniocentesis at 14 weeks or less.  

PubMed

The recent clinical trials indicate that EA is feasible. The use of ancillary tools, such as ultrasound, requires only a slight modification of the previously established techniques for MA. The amniotic fluid can be obtained and cultured. Combining the reported populations sampled, the procedural and cytogenetic failure rate were 2.0% and 0.3% respectively. The necessary information for prenatal diagnosis in the situations listed previously can be obtained. The one exception to this would be the patient at increased risk for NTD. As noted above, diagnostic levels for AFAFP have been established beginning at 13 weeks gestation. Therefore, amniocentesis before 13 weeks gestation should not be considered an option for these patients. The majority of the findings in these "pilot" studies have been promising, but the issue regarding the safety of EA has not been answered. Harrison et al. theorized that the function of the physiology hydramnios was to "provide a distention growth stimulus to the uterus ... and conversely to share in the maintenance of uterine inhibition." The amniotic fluid is constantly being replaced, having a complete turnover approximately every 3 hours. Does the reduction in volume, for even a short period of time, change the "distensive forces" enough to increase the pregnancy loss rate? Later publications have associated MA with increased rates of congenital orthopedic anomalies and neonatal pulmonary compromise. The true existence of these complications continues to be debated in the literature. Two of the authors have indicated that none of the reported neonates exposed to EA have had such anomalies.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3042220

Johnson, A; Godmilow, L

1988-06-01

454

Isentropic Compression of Multicomponent Mixtures of Fuels and Inert Gases  

NASA Technical Reports Server (NTRS)

In selected aerospace applications of the fuels hydrazine and monomethythydrazine, there occur conditions which can result in the isentropic compression of a multicomponent mixture of fuel and inert gas. One such example is when a driver gas such as helium comes out of solution and mixes with the fuel vapor, which is being compressed. A second example is when product gas from an energetic device mixes with the fuel vapor which is being compressed. Thermodynamic analysis has shown that under isentropic compression, the fuels hydrazine and monomethylhydrazine must be treated as real fluids using appropriate equations of state. The appropriate equations of state are the Peng-Robinson equation of state for hydrazine and the Redlich-Kwong-Soave equation of state for monomethylhydrazine. The addition of an inert gas of variable quantity and input temperature and pressure to the fuel compounds the problem for safety design or analysis. This work provides the appropriate thermodynamic analysis of isentropic compression of the two examples cited. In addition to an entropy balance describing the change of state, an enthalpy balance is required. The presence of multicomponents in the system requires that appropriate mixing rules are identified and applied to the analysis. This analysis is not currently available.

Barragan, Michelle; Julien, Howard L.; Woods, Stephen S.; Wilson, D. Bruce; Saulsberry, Regor L.

2000-01-01

455

Formulation development of metoprolol succinate and hydrochlorothiazide compression coated tablets.  

PubMed

The purpose of present research work was to design and optimize compression coated tablet to provide an immediate release of hydrochlorothiazide in stomach and extended release of metoprolol succinate in intestine. Compression coated tablet was prepared by direct compression method which consisted of metoprolol succinate extended release core tablet and hydrochlorothiazide immediate release coat layer. Barrier coating of Hydroxy Propyl Methyl Cellulose (HPMC) E15LV was applied onto the core tablets to prevent burst release of metoprolol succinate in acidic medium. A 32 full factorial design was employed for optimization of the amount of polymers required to achieve extended release of drug. The percentage drug release at given time Q3, Q6, Q10, Q22; were selected as dependent variables. Core and compression coated tablets were evaluated for pharmaco-technical parameters. In vitro drug release of optimized batch was found to comply with Pharmacopoeial specifications. Desired release of metoprolol succinate was obtained by suitable combination of HPMC having high gelling capacity and polyethylene oxide having quick gelling capacity. The mechanism of release of metoprolol succinate from all batches was anomalous diffusion. Optimised batch was stable at accelerated conditions up to 3 months. Thus, compression coated tablet of metoprolol succinate and hydrochlorothiazide was successfully formulated. PMID:23017092

Shah, Ritesh; Parmar, Swatil; Patel, Hetal; Pandey, Sonia; Shah, Dinesh

2013-12-01

456

Modified fixed-length entropy coding for robust video compression  

NASA Astrophysics Data System (ADS)

This paper proposes a modified Fixed-length Entropy Coding(FLC) algorithm suitable for MPEG-like hybrid-based video compression. In such applications, the alphabets of symbols sending to entropy coding are of heavy-tail distributions. Previously proposed algorithms either have poor compression efficiency or are computationally complex in this situation. The technique proposed in this paper extends the previous work for the important case of large alphabets by introducing a new alphabet segmentation and splitting algorithm. Simulation results show that for sources with relative large, skewed and heavy-tail distributed alphabets, the proposed approach has faster alphabet shrinking and higher compression efficiency compared with previous FLC approaches. A hybrid video codec using the proposed FLC is implemented and compared to a MPEG-2 video codec in both noise-free and noisy environments. The results demonstrate that the proposed FLC has similar compression gain as common VLC, and FLC codes provide more robustness to video streams than VLC codes. The proposed technique can be used to compress video sequences transmitted over channels with random bit errors.

Zhang, Guanjun; Stevenson, Robert L.

2003-05-01

457

Near-wall modelling of compressible turbulent flows  

NASA Technical Reports Server (NTRS)

Work was carried out to extend the near-wall models formulated for the incompressible Reynolds stress equations to compressible flows. The idea of splitting the compressible dissipation function into a solenoidal part that is not sensitive to changes of compressibility indicators and a compressible part that is directly affected by these changes is adopted. This means that all models involving the dissipation rate could be expressed in terms of the solenoidal dissipation rate and an equation governing its transport could be formulated to close the set of compressible Reynolds stress equations. The near-wall modelling of the dissipation rate equation is investigated and its behavior near a wall is studied in detail using k-epsilon closure. It is found that all existing modelled equations give the wrong behavior for the dissipation rate near a wall. Improvements are suggested and the resultant behavior is found to be in good agreement with near-wall data. Furthermore, the present modified k-epsilon closure is used too calculate a flat plate boundary layer and the results are compared with four existing k-epsilon closures. These comparisons show that all closures tested give essentially the same flow properties, except in a region very close to the wall. In this region, the present k-epsilon closure calculations are in better agreement with measurements and direct simulation data; in particular, the behavior of the dissipation rate.

So, Ronald M. C.

1990-01-01

458

Compressible Turbulent Channel Flows: DNS Results and Modeling  

NASA Technical Reports Server (NTRS)

The present paper addresses some topical issues in modeling compressible turbulent shear flows. The work is based on direct numerical simulation of two supersonic fully developed channel flows between very cold isothermal walls. Detailed decomposition and analysis of terms appearing in the momentum and energy equations are presented. The simulation results are used to provide insights into differences between conventional time-and Favre-averaging of the mean-flow and turbulent quantities. Study of the turbulence energy budget for the two cases shows that the compressibility effects due to turbulent density and pressure fluctuations are insignificant. In particular, the dilatational dissipation and the mean product of the pressure and dilatation fluctuations are very small, contrary to the results of simulations for sheared homogeneous compressible turbulence and to recent proposals for models for general compressible turbulent flows. This provides a possible explanation of why the Van Driest density-weighted transformation is so successful in correlating compressible boundary layer data. Finally, it is found that the DNS data do not support the strong Reynolds analogy. A more general representation of the analogy is analysed and shown to match the DNS data very well.

Huang, P. G.; Coleman, G. N.; Bradshaw, P.; Rai, Man Mohan (Technical Monitor)

1994-01-01

459

Effects of Progressive Resistance Training Integrated with Foot and Ankle Compression on Spatiotemporal Gait Parameters of Individuals with Stroke  

PubMed Central

[Purpose] The purpose of this study was to investigate the effect of progressive resistance training (PRT) integrated with foot and ankle compression on the gait ability of post-stroke patients. [Subjects and Methods] Participants were randomly allocated to two groups: the PRT group (n=14) and the control group (n=14). Subjects in the PRT group received training for 30 minutes, five days per week, for a period of six weeks. Gait ability was evaluated using the RsScan system. [Results] Use of PRT integrated with foot and ankle compression resulted in significant improvements in temporal parameters (gait velocity, step time, and double limb support) and spatial parameters (step length, stride length, and heel-to- heel base of support). [Conclusion] Progressive resistance training integrated with foot and ankle compression improved the gait ability of stroke patients. These results suggest the feasibility and suitability of integration of PRT with foot and ankle compression for individuals with stroke.

Lee, Na Kyung; Son, Sung Min; Nam, Seok Hyun; Kwon, Jung Won; Kang, Kyung Woo; Kim, Kyoung

2013-01-01

460

Effects of progressive resistance training integrated with foot and ankle compression on spatiotemporal gait parameters of individuals with stroke.  

PubMed

[Purpose] The purpose of this study was to investigate the effect of progressive resistance training (PRT) integrated with foot and ankle compression on the gait ability of post-stroke patients. [Subjects and Methods] Participants were randomly allocated to two groups: the PRT group (n=14) and the control group (n=14). Subjects in the PRT group received training for 30 minutes, five days per week, for a period of six weeks. Gait ability was evaluated using the RsScan system. [Results] Use of PRT integrated with foot and ankle compression resulted in significant improvements in temporal parameters (gait velocity, step time, and double limb support) and spatial parameters (step length, stride length, and heel-to- heel base of support). [Conclusion] Progressive resistance training integrated with foot and ankle compression improved the gait ability of stroke patients. These results suggest the feasibility and suitability of integration of PRT with foot and ankle compression for individuals with stroke. PMID:24259765

Lee, Na Kyung; Son, Sung Min; Nam, Seok Hyun; Kwon, Jung Won; Kang, Kyung Woo; Kim, Kyoung

2013-10-01

461

Dual Work Families: New Sex Roles.  

National Technical Information Service (NTIS)

The ways men and women in dual work families wish to divide or share commitments to work and parenting were studied. Seventy-five dual work couples in which both parents work at least 35 hours a week and were responsible for at least one pre-school child ...

A. Hochschild

1982-01-01

462

The Shape of Work to Come: Prospects.  

ERIC Educational Resources Information Center

If education is considered a nonwork activity, any change in the individual's work time will pose new challenges for educational policy. Trends in the relationship between work and nonwork time are presented. Topics include: work weeks, women workers, demographic changes, part-time work, shiftwork, technological changes and family living.

Bengtsson, Jarl

1979-01-01

463

Efficient Data Compression Techniques for Weather Data.  

National Technical Information Service (NTIS)

We collaborated with the Naval Research Laboratory (NRL), Marine Meteorology Division in Monterey, CA to develop novel and efficient data compression techniques for weather data. We developed a differential coding algorithm for lossless compression of rad...

D. Pan

2011-01-01

464

Infraspinatus muscle atrophy from suprascapular nerve compression.  

PubMed

Muscle weakness without pain may signal a nerve compression injury. Because these injuries should be identified and treated early to prevent permanent muscle weakness and atrophy, providers should consider suprascapular nerve compression in patients with shoulder muscle weakness. PMID:24463748

Cordova, Christopher B; Owens, Brett D

2014-02-01

465

Adaptive Data Compression System Study, Executive Summary.  

National Technical Information Service (NTIS)

The procedures used to examine the data compression algorithms for the CLUSTER and SOHO missions are presented. A number of compression algorithms were evaluated. Some of these algorithms are well known in the literature, while others have been developed ...

N. S. Bray C. K. Chan A. K. Ward B. E. Patchett M. A. Birdseye

1988-01-01

466

Thermal compression modulus of polarized neutron matter.  

National Technical Information Service (NTIS)

We applied the equation of state for pure polarized neutron matter at finite temperature, calculated previously, to calculate the compression modulus. The compression modulus of pure neutron matter at zero temperature is very large and reflects the stiffn...

M. Abd-Alla

1990-01-01

467

Physical examination of upper extremity compressive neuropathies.  

PubMed

A thorough history and physical examination are vital to the assessment of upper extremity compressive neuropathies. This article summarizes relevant anatomy and physical examination findings associated with upper extremity compressive neuropathies. PMID:23026457

Popinchalk, Samuel P; Schaffer, Alyssa A

2012-10-01

468

CRUSH: The NSI Data Compression Utility.  

National Technical Information Service (NTIS)

CRUSH is a data compression utility that provides the user with several lossless compression techniques available in a single application. It is intended that the future development of CRUSH will depend upon feedback from the user community to identify ne...

E. Seiler

1991-01-01

469

ADVANCED RECIPROCATING COMPRESSION TECHNOLOGY (ARCT)  

SciTech Connect

The U.S. natural gas pipeline industry is facing the twin challenges of increased flexibility and capacity expansion. To meet these challenges, the industry requires improved choices in gas compression to address new construction and enhancement of the currently installed infrastructure. The current fleet of installed reciprocating compression is primarily slow-speed integral machines. Most new reciprocating compression is and will be large, high-speed separable units. The major challenges with the fleet of slow-speed integral machines are: limited flexibility and a large range in performance. In an attempt to increase flexibility, many operators are choosing to single-act cylinders, which are causing reduced reliability and integrity. While the best performing units in the fleet exhibit thermal efficiencies between 90% and 92%, the low performers are running down to 50% with the mean at about 80%. The major cause for this large disparity is due to installation losses in the pulsation control system. In the better performers, the losses are about evenly split between installation losses and valve losses. The major challenges for high-speed machines are: cylinder nozzle pulsations, mechanical vibrations due to cylinder stretch, short valve life, and low thermal performance. To shift nozzle pulsation to higher orders, nozzles are shortened, and to dampen the amplitudes, orifices are added. The shortened nozzles result in mechanical coupling with the cylinder, thereby, causing increased vibration due to the cylinder stretch mode. Valve life is even shorter than for slow speeds and can be on the order of a few months. The thermal efficiency is 10% to 15% lower than slow-speed equipment with the best performance in the 75% to 80% range. The goal of this advanced reciprocating compression program is to develop the technology for both high speed and low speed compression that will expand unit flexibility, increase thermal efficiency, and increase reliability and integrity. Retrofit technologies that address the challenges of slow-speed integral compression are: (1) optimum turndown using a combination of speed and clearance with single-acting operation as a last resort; (2) if single-acting is required, implement infinite length nozzles to address nozzle pulsation and tunable side branch absorbers for 1x lateral pulsations; and (3) advanced valves, either the semi-active plate valve or the passive rotary valve, to extend valve life to three years with half the pressure drop. This next generation of slow-speed compression should attain 95% efficiency, a three-year valve life, and expanded turndown. New equipment technologies that address the challenges of large-horsepower, high-speed compression are: (1) optimum turndown with unit speed; (2) tapered nozzles to effectively reduce nozzle pulsation with half the pressure drop and minimization of mechanical cylinder stretch induced vibrations; (3) tunable side branch absorber or higher-order filter bottle to address lateral piping pulsations over the entire extended speed range with minimal pressure drop; and (4) semi-active plate valves or passive rotary valves to extend valve life with half the pressure drop. This next generation of large-horsepower, high-speed compression should attain 90% efficiency, a two-year valve life, 50% turndown, and less than 0.75 IPS vibration. This program has generated proof-of-concept technologies with the potential to meet these ambitious goals. Full development of these identified technologies is underway. The GMRC has committed to pursue the most promising enabling technologies for their industry.

Danny M. Deffenbaugh; Klaus Brun; Ralph E. Harris; J. Pete Harrell; Robert J. Mckee; J. Jeffrey Moore; Steven J. Svedeman; Anthony J. Smalley; Eugene L. Broerman; Robert A Hart; Marybeth G. Nored; Ryan S. Gernentz; Shane P. Siebenaler

2005-12-01

470

Value of Micro-CT for Monitoring Spinal Microvascular Changes after Chronic Spinal Cord Compression.  

PubMed

Neurological degeneration can occur after compression of the spinal cord. It is widely accepted that spinal cord compression leads to ischemic lesions and ultimately neurological dysfunction due to a narrowed spinal canal. Therefore, an in-depth understanding of the pathogenesis of spinal cord compression injury is required to help develop effective clinical interventions. In the present study, we propose a new method of quantitative 3D micro-CT to observe microvascular events in a chronic spinal cord compression rat model. A total of 36 rats were divided into two groups: sham control group (n = 12) and compressive spinal cord injury group (n = 24). Rats were scarified at four weeks after surgery. In each group, CD34 micro-vessel immunohistochemical staining was performed in half of the animals, while micro-CT scanning was performed in the other half. Microvessel density (MVD) was measured after immunohistochemical staining, while the vascular index (VI) was measured in 3D micro-CT. In comparison with sham control, abnormal somatosensory evoked potentials (SEP) can be seen in all 24 cases of the compression group, and VI shows the amount of microvessels reduced consistently and significantly (p < 0.01). A significant correlation is also found between MVD and VI (r = 0.95, p < 0.01). These data suggest that quantitative 3D micro-CT is a sensitive and promising tool for investigating microvascular changes during chronic compressive spinal cord injury. PMID:25003643

Long, Hou-Qing; Xie, Wen-Han; Chen, Wen-Li; Xie, Wen-Lin; Xu, Jing-Hui; Hu, Yong

2014-01-01

471

Simultaneous denoising and compression of multispectral images  

NASA Astrophysics Data System (ADS)

A new technique for denoising and compression of multispectral satellite images to remove the effect of noise on the compression process is presented. One type of multispectral images has been considered: Landsat Enhanced Thematic Mapper Plus. The discrete wavelet transform (DWT), the dual-tre