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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



2009 Summer 4-Day Work Week Evaluation Report  

ERIC Educational Resources Information Center

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

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



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

Code of Federal Regulations, 2013 CFR

...2013-01-01 false Premium pay for holiday work for employees on compressed work schedules...610.407 Premium pay for holiday work for employees on compressed work schedules...schedule, a full-time employee is entitled to overtime pay under applicable...



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…

Hellyer, Lyle


Comparison of the working domains of some compression heat pumps and a compression-absorption heat pump  

Microsoft Academic Search

The working domains of a model of a compression heat pump using different fluids and a model of a compression-absorption heat pump using water-ammonia mixtures are defined, plotted and discussed. These domains are defined by means of limiting values for their electrical coefficient of performance, volumetric heating capacity, and low and high pressure. In the case studied in the present

O Brunin; M Feidt; B Hivet



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


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



More in Four. An Evaluation of the Four-Day Work Week in a VDOT Residency.  

National Technical Information Service (NTIS)

The report describes the evaluation of an experimental 4-day, 10-hour-per-day work week used by the Virginia Department of Transportation's (VDOT) Chatham Residency between May 15, 1995, and October 6, 1995. The residency, totaling over 100 peope, adopted...

D. S. Roosevelt



Wet compression versus dry compression in heat pumps working with pure refrigerants or non-azeotropic binary mixtures for different heating applications  

Microsoft Academic Search

Wet compression versus dry compression in heat pumps working with pure refrigerants or non-azeotropic binary mixtures is investigated in this paper. In total 34 pure refrigerants as well as 31 non-azeotropic binary mixtures at different concentrations are considered. This resulted in approximately 300 different mixtures being analysed. The pure refrigerants were analysed for three different heating applications found in practice:

P. P. J Vorster; J. P Meyer



Performance Estimation of Absorption/Compression Cycle Using Working Pair Dimethyle Ether/Methanol  

NASA Astrophysics Data System (ADS)

This paper presents the performance estimation of hybrid absorption/compression heat pump cycle, which use dimethyl ether (DME) and methanol pair as a working fluid. The disadvantage of the DME as a refrigerant is that it is flammable. But it has several advantages from the environmental aspects; toxicity is very low, and GWP is small. The first purpose of this study is to estimate the reduction of the loss of the heat exchangers, by use of absorption/compression cycle. And the second purpose is to lower the working pressure to reduce the possibility of the leakage of the working fluids. Two hybrid systems are supposed as models; one is absorption/compression system with single stage solution circuit, and another is an absorption/compression system with generator/absorber heat exchange cycle. The former cycle exceeds the cooling and heating COPs of pure DME cycle, reducing the maximum pressure about 130 kPa. And the latter system increases the heating COP by 6 to 36% with the working pressure range about 150-260 kPa.

Endo, Naok; Maeda, Tetsuhiko; Hasegawa, Yasuo


Implementation of Compressed Work Schedules: Participation and Job Redesign as Critical Factors for Employee Acceptance.  

ERIC Educational Resources Information Center

|Analyzes the effects of an implementation of a three-day/thirty-eight hour (3/38) work schedule among information systems personnel (N=84). Data showed that 18 months after implementation, 3/38 employees still strongly favor the compressed schedule. Data also suggest substantial organizational payoffs including reductions in sick time, overtime,…

Latack, Janina C.; Foster, Lawrence W.



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



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


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

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



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

ERIC Educational Resources Information Center

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

van Ginneken, Wouter



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



Compression Heat Pump Utilizing Water-Ethanol Mixture as a Working Fluid  

NASA Astrophysics Data System (ADS)

Theoretical cycle analysis was done on compression heat pump system, which uses water -ethanol mixture as a working fluid. Working temperature level was set below 100°C. At the low temperature region the pressure of the suction gas is low, and the influence of mechanical loss of the compressor on coefficient of performance (COP) will be large. Relations of COPs and mechanica1 loss of the compressor has been made clear on the ethanol mol fraction range (0 to 1). Water-ethanol mixture cycle can increase COP and lower the working temperature compared with a water cycle. Another effect of adding ethanol is to decrease the irreversible loss at the heat exchangers. As the water -ethanol mixture is a non-azeotropic mixture, temperature changes in two phase regions. This characteristic is valid when a second coolant is used.

Endo, Naoki; Yabe, Akira; Yamashita, Iwao


Compressed Air Pipework Installations Up to 30 Bar Working Pressure. Standard Specification (M and E) No. 136.  

National Technical Information Service (NTIS)

The report covers a specification related to the design, manufacture, works testing, installation and site testing of piping, fittings, valves and other components for compressed air installations. The specification does not cover the requirements for air...



Finite element study of working level separation at the Weeks Island salt dome  

SciTech Connect

The Weeks Island salt dome has a former two-level room-and-pillar salt mine which is now filled with oil as part of the Strategic Petroleum Reserve (SPR). This study is a determination of the safe separation of the SPR level from a postulated outburst beneath it. A series of finite element structural analyses model the mine excavation, filling, outburst occurrence, and subsequent time until the year 2045 for various postulated separation distances. It is found that if the outburst is 100 ft or more from the SPR then there is no discernable effect on the SPR. If the outburst is only 50 ft below the SPR, then there is a discernable but nonthreatening effect. 21 references, 21 figures, 2 tables.

Preece, D.S.; Krieg, R.D.



Hybrid Vapor Compression Ejector Cycle: Presentation to IAPG Mechanical Working Group.  

National Technical Information Service (NTIS)

This is a presentation of the hybrid vapor compression ejector cycle. An overview of the hybrid vapor compression ejector heat pump cycle developed under an American Recovery and Reinvestment Act funded contract is provided.

P. Verma T. Radcliff



Sleep restriction for the duration of a work week impairs multitasking performance.  


It is important to develop shift schedules that minimise the chance for sleep-related human error in safety-critical domains. Experimental data on the effects of sleep restriction (SR) play a key role in this development work. In order to provide such data, we conducted an experiment in which cognitively demanding and long-duration task performance, simulating task performance at work, was measured under SR and following recovery. Twenty healthy male volunteers, aged 19-29 years, participated in the study. Thirteen of them had first two baseline days (8-h sleep opportunity per day), then five SR days (4-h sleep) and finally two recovery days (8-h sleep). Seven controls were allowed to sleep for 8 h each night. On each experimental day, multitask performance was tested in 50-min sessions, physiological sleepiness was evaluated during multitask performance using electroencephalogram (EEG)/electrooculogram (EOG) recordings, and psychomotor vigilance task performance and Karolinska Sleepiness Scale were recorded. Sleep-wake rhythm was monitored throughout the experiment. The multitask performance progressively deteriorated as a result of prolongation of the SR and the time spent on the task. The effect was significant at group level, but individual differences were large: performance was not markedly deteriorated in all participants. Similar changes were observed also in EEG/EOG-defined sleepiness. The recovery process of performance and sleepiness from the SR continued over the two recovery sleep opportunities. In all, our findings emphasise the importance of shift systems that do not restrict sleep for several consecutive days. PMID:20408942

Haavisto, Marja-Leena; Porkka-Heiskanen, Tarja; Hublin, Christer; Härmä, Mikko; Mutanen, Pertti; Müller, Kiti; Virkkala, Jussi; Sallinen, Mikael



Three-week integrated body weight reduction programme markedly improves performance and work capacity in severely obese patients.  


The aim of this study was to assess the effects on performance and work capacity of a short-term (3-week) integrated body weight reduction programme consisting of an energy-restricted diet, nutritional education, psychological counselling and aerobic exercise training at a constant metabolic load (5 days/week) in 71 severely obese patients (18 males and 53 females aged 29.3 +/- 0.8 years, with a mean weight of 113.8 +/- 2.2 kg and a mean BMI of 41.3 +/- 0.5 kg/m(-2)). Body mass and composition, and maximum oxygen consumption (VO2max) were determined before and after the programme. The caloric equivalent of work output and a performance index (PI) during 10 min of bicycle ergometer pedalling (50-60 rpm) and 20 min of treadmill walking (incline 0-3%) at a constant metabolic load (50% of individual VO2max during the preliminary conditioning period--1st week--and 60% during the exercise conditioning period--2nd and 3rd week) were evaluated daily throughout the study. After the programme, body mass reduced significantly (-4.5%, p<0.001), the weight loss being sustained entirely by a significant reduction in fat mass (-7.6%, p<0.001) without any significant changes in fat-free mass. Absolute and body mass-related VO2max significantly increased by respectively 14.5% and 20.2% (p<0.001). Both daily work output during constant metabolic load (ANOVA, p<0.05-0.001) and PI (ANOVA, p<0.05-0.001) increased significantly during each week of the programme, leading to a total increase in work output in response to exercise conditioning of 44.6 +/- 5.8 kcal. It is concluded that the changes in exercise capacity induced by the present programme offer significant advantages for obese patients that can be quantified in terms of an improvement in their ability to perform everyday activities, thus contributing towards improving their quality of life. PMID:12880187

Sartorio, A; Ottolini, S; Agosti, F; Massarini, M; Lafortuna, C L



A New Compressed Suffix Tree Supporting Fast Search and Its Construction Algorithm Using Optimal Working Space  

Microsoft Academic Search

\\u000a The compressed suffix array and the compressed suffix tree for a given string S are full-text index data structures occupying O(nlog|?|) bits where n is the length of S and ? is the alphabet from which symbols of S are drawn. When they were first introduced, they were constructed from suffix arrays and suffix trees, which implies they\\u000a were not

Dong Kyue Kim; Heejin Park



Industrial heat recovery by absorption\\/compression heat pump using TFE–H 2O–TEGDME working mixture  

Microsoft Academic Search

The thermodynamic performance of a single-stage absorption\\/compression heat pump using the ternary working fluid Trifluoroethanol–Water–Tetraethylenglycol dimethylether (TFE–H2O–TEGDME) for upgrading waste heat has been studied. A simulation program has been developed using a mathematical model based on mass and energy balances in all components of the cycle and thermodynamic equilibrium considerations. In order to establish the optimum operating conditions of the

M Bourouis; M Nogués; D Boer; A Coronas



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, 2013 CFR

...for all weekly overtime hours in excess of 56 which he works in a workweek...excess of 40, and works 60 hours in a...workday for which overtime compensation...for 40 hours of work and in the amount...with $10.67 as overtime premium for...



Architecture Week  

NSDL National Science Digital Library

Based in Eugene, Oregon, Architecture Week is a magazine that is intended for design and building professionals, and their work includes profiles of new building techniques, historic preservation issues, and architectural practice. Visitors can view the current issues online here, and they will also want to look through their "And More" area. Here they will find sections like "Blog Center", "New Products", "Jobs" and "Conferences". Also, visitors can subscribe to their "ArchitectureWeek Notes", which is a weekly email newsletter. Recent articles on the site have included a piece on historic sites in the United States that are at risk of being demolished and another piece on the importance of listening to clients before starting a major architectural project.


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

ERIC Educational Resources Information Center

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

Blankenship, Ted



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.


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

ERIC Educational Resources Information Center

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

Robert Wood Johnson Foundation, 2013



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.



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.



Linear-Time Construction of Compressed Suffix Arrays Using o(n log n)Bit Working Space for Large Alphabets  

Microsoft Academic Search

\\u000a The suffix array is a fundamental index data structure in string algorithms and bioinformatics, and the compressed suffix array (CSA) and theFM-index are its compressed versions. Many algorithms for constructing these index data structures have been developed. Recently,\\u000a Hon et al. [11] proposed a construction algorithm using O(n ·loglog|?|) time and O(nlog|?|)-bit working space, which is the fastest algorithm using

Joong Chae Na



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


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

ten Brummelhuis, Lieke L; Bakker, Arnold B



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.  


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. PMID:23320031

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



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



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

PubMed Central

Background Low back pain (LBP) and leisure time physical activity (LTPA) are considered to be closely related, and clinical guidelines for the treatment of acute LBP recommend patients stay physically active. However, the documentation for this recommendation is sparse and based on studies involving patient populations. The purpose of the study was (1) to investigate the correlation between LBP and LTPA on a weekly basis over the course of a year in a high-risk group of cleaners; and (2) to investigate if maintaining LTPA during an episode of acute LBP has a positive effect on LBP intensity in the subsequent 4 weeks. Methods 188 cleaners consented to participate in a 52-week text message survey about hours of LTPA and intensity of LBP (from 0 to 9) over the previous 7 days. The correlation between LBP and LTPA was calculated by Pearson correlation coefficient. During an episode of acute LBP, a mixed effect logistic regression model was used to investigate whether cleaners who maintain LTPA have a lower pain intensity and higher probability of returning to initial pain intensity within the following four weeks compared with cleaners who decrease LTPA during acute LBP. Results The correlation between weekly LTPA and LBP data was negative, but numerically low (r = -0.069) and statistically insignificant (p = 0.08). Among the 82 cleaners experiencing at least one episode of acute LBP, those maintaining LTPA during an episode of acute LBP did not have a lower pain intensity (average LBP intensity difference between groups of 0.06; 95% confidence interval (95% CI) of -0.417 to 0.539) or higher probability of returning to initial pain level (Odds ratio 1,02; 95% CI of 0.50 to 2.09) in the following four weeks compared with cleaners decreasing LTPA during acute LBP. Conclusions Hours of LTPA and intensity of LBP measured on a weekly basis throughout a year showed no close correlation. Maintaining LTPA during an episode of acute LBP did not result in a positive effect on LBP in the following 4 weeks. Documentation of LTPA recommendations for acute LBP in working populations is still needed.



Alphabet-independent linear-time construction of compressed suffix arrays using o(nlogn)-bit working space  

Microsoft Academic Search

The suffix array is a fundamental index data structure in string algorithms and bioinformatics, and the compressed suffix array (CSA) and the FM-index are its compressed versions. Many algorithms for constructing these index data structures have been developed. Recently, Hon et al. [W.K. Hon, K. Sadakane, W.K. Sung, Breaking a time-and-space barrier in constructing full-text indices, in: Proceedings of the 44th

Joong Chae Na



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


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



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.



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.


Clustering by compression  

Microsoft Academic Search

Abstract We present a new method for clustering based on compression The method doesn't use subject - specific features or background knowledge, and works as follows: First, we determine a universal similarity distance, the normal - ized compression distance or NCD, computed from the lengths of compressed data files (singly and in pairwise concatenation) Second, we apply a hierarchical clustering

Rudi Cilibrasi; Paul M. B. Vitányi



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



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


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



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)



Conference Proceedings of Defense Modeling and Simulation Office Information/Data Base Technology Working Group (I/DBTWG) Meetings Held During the Week of July 11-15, 1994.  

National Technical Information Service (NTIS)

This document contains the proceedings from the Defense Modeling and Simulation Office (DMSO) Information/Data Base Technology Working Group (I/DBTWG) meeting and related Task Force meetings held at the Institute for Defense Analysis (IDA) during the week...

I. M. Kameny



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 ÂChat with GwenÂ, 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.


Prom week  

Microsoft Academic Search

Prom Week places players in a typical high-school, abuzz with excitement over the upcoming prom. Players indirectly sculpt the social landscape by having these hapless highschoolers engage in social exchanges with each other. The results of these social exchanges are many and varied---ranging from mild fluctuations in respect to characters professing their eternal love for one another---and are informed by

Josh McCoy; Mike Treanor; Ben Samuel; Aaron A. Reed; Noah Wardrip-Fruin; Michael Mateas



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

Ms. Rachel Gillis (Arsenal Technical High School)



Collaborative work on evaluation of ovarian toxicity. 15) Two- or four-week repeated-dose studies and fertility study of bromocriptine in female rats.  


The main focus of this study is to determine the optimal administration period concerning toxic effects on ovarian morphological changes in a repeated-dose toxicity study. To assess morphological and functional changes induced in the ovary by bromocriptine, the compound was administered to female rats at dose levels of 0, 0.08, 0.4 and 2 mg/kg for the 2- or 4-week repeated-dose toxicity study, and for the female fertility study from 2 weeks prior to mating to day 7 of gestation. In the 2-week repeated-dose toxicity study, increase of ovarian weights was observed at 2 mg/kg. In the 4-week repeated-dose toxicity study, ovarian weights were increased at 0.4 and 2 mg/kg. The number of corpora luteum was increased in the 0.4 and 2 mg/kg groups of the 2- and 4-week repeated-dose toxicity studies by histopathological examination of the ovaries. Bromocriptine did not affect estrous cyclicity in 2- and 4-week repeated dosing. In the female fertility study, although animals in any groups mated successfully, no females in 0.4 and 2 mg/kg groups were pregnant. There were no adverse effects on reproductive performance in the 0.08 mg/kg group. Based on these findings, the histopathological changes in the ovary are considered important parameters for evaluation of drugs including ovarian damage. We conclude that a 2-week administration period is sufficient to detect ovarian toxicity of bromocriptine in a repeated-dose toxicity study. PMID:19265282

Kumazawa, Toshihiko; Nakajima, Atsushi; Ishiguro, Tsukasa; Jiuxin, Zhu; Tanaharu, Takashi; Nishitani, Hiromi; Inoue, Yukiko; Harada, Satoko; Hayasaka, Ikuo; Tagawa, Yoshiaki



NEW CCSDS Image Compression Recommendation.  

National Technical Information Service (NTIS)

The Consultative Committee for Space Data Systems (CCSDS) data compression working group has recently adopted a recommendation for image data compression, wah a final release expected in 2005. The algorithm adopted in the recommendation consists of a two-...

P. S. Yeh P. Armbruster A. Kiely B. Masschelein



Electrical stimulation for chronic non-specific low back pain in a working-age population: a 12-week double blinded randomized controlled trial  

PubMed Central

Background Non-invasive electrotherapy is commonly used for treatment of chronic low back pain. Evidence for efficacy of most electrotherapy modalities is weak or lacking. This study aims to execute a high-quality, double-blinded randomized controlled clinical trial comparing 1) H-Wave® Device stimulation plus usual care with 2) transcutaneous electrical nerve stimulation (TENS) plus usual care, and 3) Sham electrotherapy plus usual care to determine comparative efficacy for treatment of chronic non-specific low back pain patients. Methods/Design Patients- Chronic non-specific low back pain patients between ages of 18–65 years, with pain of at least 3 months duration and minimal current 5/10 VAS pain. Patients will have no significant signs or symptoms of lumbosacral nerve impingement, malignancy, spinal stenosis, or mood disorders. Study design- Double blind RCT with 3 arms and 38 subjects per arm. Randomization by permuted blocks of random length, stratified by Workers Compensation claim (yes vs. no), and use of opioids. The null hypothesis of this study is that there are no statistically significant differences in functional improvement between treatment types during and at the end of a 12-week week treatment period. Data collection- Subjective data will be collected using Filemaker Pro™ database management collection tools. Objective data will be obtained through functional assessments. Data will be collected at enrollment and at 1, 4, 8, and 12 weeks for each participant by a blinded assessor. Interventions- H-Wave® device stimulation (Intervention A) plus usual care, transcutaneous electrical nerve stimulation (TENS) (Intervention B) plus usual care, and sham electrotherapy plus usual care (control). Each treatment arm will have identical numbers of visits (4) and researcher contact time (approximately 15 hours). Outcomes- Primary outcome measure: Oswestry Disability Index. Secondary measures include: Rowland Morris Instrument, VAS pain score, functional evaluation including strength when pushing and pulling, pain free range of motion in flexion and extension. Outcome measures assessed at baseline, 1, 4, 8, and 12 weeks. Treatment failure will be defined if patient terminates assigned treatment arm for non-efficacy or undergoes invasive procedure or other excluded cointerventions. Data will be analyzed using intention-to-treat analysis and adjusted for covariates related to LBP (e.g. age) as needed. Discussion Study strengths include complex randomization, treatment group allocation concealment, double blinding, controlling for co-interventions, rigorous inclusion criteria, assessment of compliance, plans for limiting dropout, identical assessment methods and timing for each treatment arm, and planned intention-to-treat analyses.



Part-Time Work and Other Flexible Options. ERIC Digest No. 192.  

ERIC Educational Resources Information Center

|Options for flexible work schedules such as job sharing, compressed work weeks, reduced hours, work at home, and flextime have provided employees with the means to realize a better balance between work and family and engage simultaneously in more than one endeavor (for example, school and work or two careers). The same options can also lead to…

Brown, Bettina Lankard


Compressed Air  

NSDL National Science Digital Library

This website includes an animation which demonstrates a basic overview of compressed air for use in machines. Objective: Describe the different tools that can be used with compressed air. You can find the animation under the heading "Automation Technology."



Database Compression Using an Offline Dictionary Method  

Microsoft Academic Search

Off-line dictionary compression is becoming more attractive for applications where compressed data are searched directly in\\u000a compressed form. While there has been large body of related work describing specific database compression algorithms, the\\u000a Hibase [10] architecture is unique in processing queries in compressed data. However, this technique does not compress the representation\\u000a of strings in the domain dictionaries. Primary keys,

Douglas R. Mcgregor; John Wilson



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...




NSDL National Science Digital Library

Authored and curated by David P. Stern, 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 P. (David Peter), 1931-



Compression embedding  


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.



Compression embedding  


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)



Signal Compression Lab  

NSDL National Science Digital Library

The Signal Compression Lab (SCL) is a part of the Electrical and Computer Engineering Department at the University of California, Santa Barbara. "Current research activities at SCL include low bit rate speech coding, wideband speech and audio compression, speech modeling and synthesis," and many more focus areas involving data compression of various forms of media. A large collection of informative demonstrations and slide presentations illustrate the group's work. Many of the SCL staff have publications available for downloading, which are divided into several categories for easy browsing.



Compression embedding  


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)



Compression embedding  

SciTech Connect

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.



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.



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.




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?


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


Weekly Epidemiological Record  


... WHO .int site Submit Advanced search Weekly Epidemiological Record (WER) Subnavigation WER Home 2013: Volume 88 2012: ... 85 2009: Volume 84 Archives The Weekly Epidemiological Record (WER) The Weekly Epidemiological Record (WER) serves as ...


Sandia shock compression database  

Microsoft Academic Search

An authoritative, updatable, and searchable bibliographic database whose topical area is shock compression is currently under development. The database is derived from published scientific articles and reports with current emphasis in the subareas of strength, phase transitions, spall, and stress-volume relations. The content of the cited work is described by keywords which are selected and reviewed by scientific advisors. Keywords

C. E. Anderson; J. S. Wilbeck; J. C. Hokanson; J. R. Asay; D. E. Grady; R. A. Graham; M. E. Kipp



Compressed sensing  

Microsoft Academic Search

Suppose x is an unknown vector in Rm (depending on context, a digital image or signal); we plan to acquire data and then reconstruct. Nominally this 'should' requirem samples. But suppose we know a priori thatx is compressible by transform coding with a known transform, and we are allowed to acquire data aboutx by measuringn general linear functionals - rather

David L. Donoho



75 FR 20891 - National Volunteer Week, 2010  

Federal Register 2010, 2011, 2012, 2013

...8500 of April 16, 2010 National Volunteer Week, 2010 By the President of the United States...and their work changed our country. This week, we recognize their enduring contributions...local concerns. During National Volunteer Week, we honor the ordinary people who...



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

SciTech Connect

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

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



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



Compression-aware demosaicing methods  

NASA Astrophysics Data System (ADS)

In many digital color-image systems, most notably digital cameras, raw data from the sensor is processed to produce a pleasing image. One of the main steps in this process is demosaicing, which is the process of interpolating the raw data into a full color image. The resulting image is in turn compressed to enable compact storage. Each of these two steps, namely the demosaicing and compression, creates its own artifacts on the final image. In this work we consider the two stages together, and design a demosaicing algorithm which takes into account the fact that the final image is to be compressed. Examples are given to demonstrate the above ideas.

Baharav, Zachi Z.; Kakarala, Ramakrishna



Collaborative work to evaluate toxicity on male reproductive organs by repeated dose studies in rats 11). Testicular toxicity of 2- or 4-week repeated or single-dose administration of a novel platinum complex.  


A novel platinum complex, compound C, developed as an antitumor agent, was intravenously administered at 10 mg/kg/day to 6-week-old and 8-week-old rats. After 4 weeks of administration to the former, testicular enlargement was observed at a similar incidence as testicular atrophy and dilatation or atrophy of the seminiferous tubules was observed. Degeneration/necrosis of the seminiferous epithelium, decrease of seminiferous epithelium, formation of multinucleated giant cells, and vacuolar degeneration of Sertoli cells were also seen. These lesions were more marked in seminiferous tubules with atrophy than in those without atrophy. After 2-week administration to 8-week-old rats, slight initial-phase findings such as dilatation of seminiferous tubules and degeneration/necrosis of the seminiferous epithelium were noted in all rats. In rats administered 20 mg/kg/day, for which the administration period was shortened to 1 week due to marked weight loss, very slight initial lesions were similarly observed. However, these lesions were not easy to detect in these rats. Following single administration of a sublethal dose (80 mg/kg), testicular lesions were clearly observed 14 days after administration, but the incidence and grade of lesions were very low at 7 days. In conclusion, testicular toxicity of compound C can be clearly detected after 2-week administration, although the progression of lesions differed from the case with 4-week administration. PMID:11349435

Misawa, Y; Watanabe, K; Sakurai, T; Fujii, E; Tsukamoto, K; Kato, A; Sugimoto, T




SciTech Connect

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

Orlikowski, D; Minich, R



Compressive sensing exploiting wavelet-domain dependencies for ECG compression  

NASA Astrophysics Data System (ADS)

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

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





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."


Earth Science Week evolves  

NASA Astrophysics Data System (ADS)

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


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


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.




Center for Biologics Evaluation and Research (CBER)



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



Argonne User Week 2008  

Microsoft Academic Search

Argonne User Week 2008 started out with a unique event on the Sunday before the meeting (which was held from May 4–8, 2008. The opening reception featured the staging of a new play, Bernal's Picasso, written by Cele Abad-Zapatero and Jill Campbell. The play was based on a meeting that occurred in 1950 between the artist Pablo Picasso and crystallographer

Larry Lurio



World breastfeeding week.  


'Breastfeeding in a globalised world for peace and justice' is the theme of this year's World Breastfeeding Week, which is to be held at the beginning of August. This article explores the aims of the campaign, the obstacles and benefits of globalisation and the activities that are being held around the world. PMID:13677144

Coleridge, Hannah-Lee



A Week for Space  

ERIC Educational Resources Information Center

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

Comstock, Diane



Phun Week: Understanding Physiology  

ERIC Educational Resources Information Center

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

Limson, Mel; Matyas, Marsha Lakes



A Week of Observations  

ERIC Educational Resources Information Center

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

Colasacco, Jenne



Sandia shock compression database  

NASA Astrophysics Data System (ADS)

An authoritative, updatable, and searchable bibliographic database whose topical area is shock compression is currently under development. The database is derived from published scientific articles and reports with current emphasis in the subareas of strength, phase transitions, spall, and stress-volume relations. The content of the cited work is described by keywords which are selected and reviewed by scientific advisors. Keywords are organized to provide major and minor descriptors which summarize the technical content in considerable detail. Details of theoretical and experimental approaches are described and major emphasis is identified. In addition to bibliographic information, abstracts are also included, and a field is provided for figure captions and able headings.

Anderson, C. E.; Wilbeck, J. S.; Hokanson, J. C.; Asay, J. R.; Grady, D. E.; Graham, R. A.; Kipp, M. E.


Initial Operation of the Compressed Air Experiment at Pittsfield, Illinois.  

National Technical Information Service (NTIS)

The status of work on the compressed air energy storage experiment at Pittsfield, Illinois is briefly described. The objectives of the Pittsfield Aquifer Test are: to demonstrate the use of aquifers as compressed air storage reservoirs, to validate and mo...

T. J. Doherty R. P. Marshall L. D. Kannberg



Chemical of the Week  

NSDL National Science Digital Library

Professor Bassam Z. Shakhashiri at the University of Wisconsin-Madison adds a new chemical to this page every week. The site was created for his general chemistry courses, Chem 103 and Chem 104, to increase students' knowledge about various chemicals and their use. Users can view featured chemicals from the currently updated fall course (103) or from the spring course (104). The chemicals featured thus far include: lime, methane, uranium, the chemistry of autumn colors, and gases that emit light.

Shakhashiri, Bassam Z.



Rendering from compressed textures  

Microsoft Academic Search

We present a simple method for rendering directly from compressed textures in hardware and software rendering systems. Textures are compressed using a vector quantization (VQ) method. The advan- tage of VQ over other compression techniques is that textures can be decompressed quickly during rendering. The drawback of us- ing lossy compression schemes such as VQ for textures is that such

Andrew C. Beers; Maneesh Agrawala; Navin Chaddha



Hyperspectral Image Compression on Reconfigurable Platforms1  

Microsoft Academic Search

NASA's satellites currently do not make use of advanced image compression techniques during data transmission to earth because of limitations in the available platforms. With the advent of Field Programmable Gate Arrays (FPGAs) and Adaptive Computing technologies it is now possible to construct a system, which compresses the data stream before down linking. Our work is part of a NASA-sponsored

Thomas W. Fry; Scott Hauck



Stiffened steel plates under uniaxial compression  

Microsoft Academic Search

The stability of steel plates stiffened with tee-shape sections under uniaxial compression and combined uniaxial compression and bending was investigated using a finite element model. The emphasis of the work presented in this paper was to find the parameters that uniquely describe the strength and behaviour of stiffened steel plates. A finite element model, validated using the results of tests

I. A. Sheikh; G. Y. Grondin; A. E. Elwi



Characterization of Cemented Sand in Triaxial Compression  

Microsoft Academic Search

This work aims at studying the stress-strain-strength behavior of an artificially cemented sandy soil produced through the addition of Portland cement. An analysis of the mechanical behavior of the soil is performed from the interpretation of results from unconfined compression tests, drained triaxial compression tests with local strain measurements, and scanning electron microscopy, in which the influence of both the

Fernando Schnaid; Pedro D. M. Prietto; Nilo C. Consoli



Speech compression and synthesis  

NASA Astrophysics Data System (ADS)

This report concludes our work for the past two years on speech compression and synthesis. A real-time variable-frame-rate LPC vocoder was implemented operating at an average rate of 2000 bits/s. We also tested our mixed-source model as part of the vocoder. To improve the reliability of the extraction of LPC parameters, we implemented and tested a range of adaptive lattice and autocorrelation algoritms. For data rates above 5000 bits/s, we developed and tested a new high-frequency regeneration technique, spectral duplication, which reduces the roughness in the synthesized speech. As the first part of our effort towards a very-low-rate (VLR) vocoder, we implemented a phonetic synthesis program that would be compatible with our initial design for a phonetic recognition program. We also recorded and partially labeled a large data base of diphone templates. During the second year we continued our work toward a VLR vocoder and also developed a multirate embedded-coding speech compression program that could transmit speech at rates varying from 9600 to 2400 b/s. The phonetic synthesis program and the labeling of the diphone template network were completed. There are currently 2845 diphone templates. We also implemented an initial version of a phonetic recognizer based on a network representation of diphone templates. The recognizer allows for incremental training of the network by modification of existing templates or addition of new templates.

Berouti, M.; Makoul, J.; Schwartz, R.; Sorenson, J.



Video Compression using Vector Quantization.  

National Technical Information Service (NTIS)

This report presents some results and findings of our work on very-low-bit-rate video compression systems using vector quantization (VQ). We have identified multiscale segmentation and variable-rate coding as two important concepts whose effective use can...

M. Venkatraman H. Kwon N. M. Nasrabadi



Compressibility effects on dynamic stall  

Microsoft Academic Search

Dynamic stall delay of flow over airfoils rapidly pitching past the static stall angle has been studied by many scientists. However, the effect of compressibility on this dynamic stall behavior has been less comprehensively studied. This review presents a detailed assessment of research performed on this subject, including a historical review of work performed on both aircraft and helicopters, and

Lawrence W. Carr; M. S. Chandrasekhara



Economic and Political Weekly  

NSDL National Science Digital Library

Published by the Sameeksha Trust since 1966, Economic and Political Weekly is a social science journal that features research articles in economics, sociology, political science, and other disciplines; book reviews; commentary; columns by social scientists; statistical updates; and other content. The full text of the journal is available online dating back to January 1999, and article summaries are available for 1998. Issues appear to be placed online one month after print publication, as the November 11-17 issue was featured at the time of review.


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.




NSDL National Science Digital Library

This is the online version of the weekly syndicated newspaper feature that highlights natural phenomena and man-made events affecting the environment. Each feature consists of a world map marked with symbols to indicate the location and type of phenomenon being described; each symbol corresponds to a brief news article on the event. It is available in downloadable, black-and-white or color versions for printing and copying. Other materials available at the site include a list of newspapers that carry the feature, a set of links to sites with related information, and breaking news articles.

Newman, Steve


Atomic effect algebras with compression bases  

SciTech Connect

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

Caragheorgheopol, Dan [Department of Mathematics and Informatics, Technical University of Civil Engineering in Bucharest, 124 Lacul Tei blv., RO-020396 and 'Ilie Murgulescu' Institute of Physical Chemistry, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest (Romania); Tkadlec, Josef [Department of Mathematics, Faculty of Electrical Engineering, Czech Technical University in Prague, 166 27 Prague (Czech Republic)



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.



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.



Mechanics of the Compression Wood Response  

PubMed Central

Righting of two tilted white pine (Pinus strobus L.) stem leaders by compression wood formation was followed for 16 weeks. The natural curves and three deflection curves under added end loads were determined from weekly field photographs. Data for self-loading and cross sectional diameters were interpolated from original estimated and final measurements. A mechanical-mathematical model was developed to predict curves under zero gravity for each stem each week. The model estimated stiffness of the leaders independently for each week, and the stiffnesses were consistent throughout the experiment. A second model was developed to simulate the deflection curves assumed when the zero gravity curves were subjected to different end loads. These predicted curves were nearly identical to the observed curves from the photographs, thus verifying the assumptions in the first model. Data from this study will be used to investigate the mechanical aspects of compression wood induction and action as the stem is bent upward toward the vertical.

Archer, Robert R.; Wilson, Brayton F.



Does the quality of chest compression deteriorate when the chest compression rate is above 120/min?  


OBJECTIVES: The quality of chest compressions along with defibrillation is the cornerstone of cardiopulmonary resuscitation (CPR), which is known to improve the outcome of cardiac arrest. We aimed to investigate the relationship between the compression rate and other CPR quality parameters including compression depth and recoil. METHODS: A conventional CPR training for lay rescuers was performed 2 weeks before the 'CPR contest'. CPR anytime training kits were distributed to respective participants for self-training on their own in their own time. The participants were tested for two-person CPR in pairs. The quantitative and qualitative data regarding the quality of CPR were collected from a standardised check list and SkillReporter, and compared by the compression rate. RESULTS: A total of 161 teams consisting of 322 students, which includes 116 men and 206 women, participated in the CPR contest. The mean depth and rate for chest compression were 49.0±8.2 mm and 110.2±10.2/min. Significantly deeper chest compression depths were noted at rates over 120/min than those at any other rates (47.0±7.4, 48.8±8.4, 52.3±6.7, p=0.008). Chest compression depth was proportional to chest compression rate (r=0.206, p<0.001), but there were significantly more incomplete chest recoils at the rate of over 120/min than at any other rates (9.8%, 6.3%, 25.6%, p=0.011). CONCLUSIONS: The study showed conflicting results in the quality of chest compression including chest compression depth and chest recoil by chest compression rate. Further evaluation regarding the upper limit of the chest compression rate is needed to ensure complete full chest wall recoil while maintaining an adequate chest compression depth. PMID:23704754

Lee, Soo Hoon; Kim, Kyuseok; Lee, Jae Hyuk; Kim, Taeyun; Kang, Changwoo; Park, Chanjong; Kim, Joonghee; Jo, You Hwan; Rhee, Joong Eui; Kim, Dong Hoon



Learning in compressed space.  


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

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



AIP Weekly Physics News  

NSDL National Science Digital Library

The University of Exeter (UK) Physics Department has given new meaning to the term "value added" in its mirroring of the American Institute of Physics' weekly publication, Physics News Update. The AIP Public Information Division makes available Physics News, which provides concise coverage of new developments in physics, graphics "depicting important physics research topics and concepts," and a subset of more in-depth stories about breaking news in physics. This Exeter site provides all of the content of the AIP's Physics News Update, and enhances it by: 1) providing an archive back to September of 1990; 2) making this archive searchable; and 3) providing the reports in HTML format, with each article subject cross-referenced to any of over 25 topics from atomic physics to superconductors, allowing the user easy access to other Physics News articles on the same topics.



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



Brachial plexus compression by an iatrogenic arteriovenous fistula  

Microsoft Academic Search

Summary  A case of left brachial plexus compression by an iatrogenic arteriovenous fistula was treated by detachable balloon technique\\u000a with immediate relief of pain. Good results on paresia were obtained in a few weeks.

J. G. Tebib; J. Bascoulergue; Ch. Dumontet; A. Paupert-Ravault; B. Prallet; F. Colson; M. Bouvier



Achondroplasia and Cervicomedullary Compression: Prospective Evaluation and Surgical Treatment  

Microsoft Academic Search

The association between sudden death and cervicomedullary compression in infants with achondroplasia has been well described. Prospective clinical and imaging evaluations have been recommended to identify those infants with achondroplasia who are at risk of dying suddenly from respiratory arrest secondary to unrecognized cervicomedullary compression. Since 1988, we have prospectively evaluated 11 infants (average age 13 weeks) with achondroplasia who

Glenn L. Keiper Jr.; Bernadette Koch; Kerry R. Crone



Vertebral Compression Fractures  


Living with OI: Information on Vertebral Compression Fractures Compression fractures are a common, painful problem for children and adults who have OI. This occurs when an injury causes the spinal bone ...


Conducting fiber compression tester  


The invention measures the resistance across a conductive fiber attached to a substrate place under a compressive load to determine the amount of compression needed to cause the fiber to fail. 3 figs.

DeTeresa, S.J.



Microbunching and RF Compression  

SciTech Connect

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

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



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,


1Bit compressive sensing  

Microsoft Academic Search

Compressive sensing is a new signal acquisition technology with the potential to reduce the number of measurements required to acquire signals that are sparse or compressible in some basis. Rather than uniformly sampling the signal, compressive sensing computes inner products with a randomized dictionary of test functions. The signal is then recovered by a convex optimization that ensures the recovered

Petros T. Boufounos; Richard G. Baraniuk



Compressing Elevation Data  

Microsoft Academic Search

This paper compares several, text and image, lossless and lossy, compression techniques for regular gridded elevation data , such as DEMs. Sp compress and progcode, the best lossless methods average 2.0 bits per point on USGS DEMs, about half the size ofgzipped files, and 6.2 bits per point on ETOPO5 samples. Lossy compression produces even smaller files at moderate error

Wm. Randolph Franklin



Compressed gas manifold  


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

Hildebrand, Richard J. (Edgemere, MD); Wozniak, John J. (Columbia, MD)



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


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



An explanation for observed compression ratios in internal combustion engines  

Microsoft Academic Search

In this paper comparisons of the compression ratios, efficiencies, and work of the ideal Otto and Diesel cycles are presented at conditions that yield maximum work per cycle. The compression ratios that maximize the work of the Diesel cycle are found always to be higher than those for the Otto cycle at the same operating conditions, although the thermal efficiencies

S. A. Klein



An explanation for observed compression ratios in internal combustion engines  

SciTech Connect

In this paper comparisons of the compression ratios, efficiencies, and work of the ideal Otto and Diesel cycles are presented at conditions that yield maximum work per cycle. The compression ratios that maximize the work of the Diesel cycle are found always to be higher than those for the Otto cycle at the same operating conditions, although the thermal efficiencies are nearly identical. The compression ratios that maximize the work of the Otto and Diesel cycles compare well with the compression ratios employed in corresponding production engines.

Klein, S.A. (Mechanical Engineering Dept., Univ. of Wisconsin-Madison, Madison, WI (US))



Does Work Experience Actually Work?  

ERIC Educational Resources Information Center

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

Field, John



Does Work Experience Actually Work?  

ERIC Educational Resources Information Center

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

Field, John



Radiological Image Compression  

NASA Astrophysics Data System (ADS)

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

Lo, Shih-Chung Benedict


Why Computer Science Ed Week?  

Microsoft Academic Search

Computer Science Education Week (CSEdWeek) is a call to action to raise awareness about computing careers and the critical need to elevate computer science education at all levels. The 2nd annual CSEdWeek, which took place December 5--11, 2010, was a smashing success, thanks to incredible partner support, a new website, and engagement from the computing community. About 280 CSEdWeek-related events

Debra Richardson; Ruthe Farmer



Assessing suspected spinal cord compression  

Microsoft Academic Search

The object of this work was to evaluate the assessment and document the outcomes of cancer patients with suspected spinal\\u000a cord compression (SCC). In a retrospective cohort study of 342 episodes of suspected SCC in cancer patients evaluated by computed\\u000a tomography (CT) of the spine, a multidisciplinary team of neurologists, radiologists, and oncologists assessed the impact\\u000a of varying the anatomical

James A. Talcott; Paul C. Stomper; Frank W. Drislane; Patrick Y. Wen; Caroline C. Block; Charles C. Humphrey; Charles Lu; Ferenc Jolesz



Expand Your Child's Vocabulary: A Twelve-Week Plan.  

ERIC Educational Resources Information Center

This booklet shows parents how to help their children develop a number of strategies for understanding words by working together on a methodical, 12-week program of word study. Sections of the booklet describe the program week by week. The techniques described are: Read and Use Context; Search for Synonyms, Antonyms, Homonyms; Learn Important…

Smith, Carl B.


75 FR 48853 - National Health Center Week, 2010  

Federal Register 2010, 2011, 2012, 2013

...Proclamation 8545--National Health Center Week, 2010 Presidential Documents Federal Register...August 5, 2010 National Health Center Week, 2010 By the President of the United States...preventive care. During National Health Center Week, we recognize the important work of...



75 FR 10993 - Save Your Vision Week, 2010  

Federal Register 2010, 2011, 2012, 2013

...8483 of March 5, 2010 Save Your Vision Week, 2010 By the President of the United States...treatment of eye conditions. Save Your Vision Week is a time for all Americans to take action...performing household chores and yard work. This week, I encourage all Americans to visit...



Adaptive compressive sensing camera  

NASA Astrophysics Data System (ADS)

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

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



Compressive optical imaging systems  

NASA Astrophysics Data System (ADS)

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

Wu, Yuehao


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



A static architecture for compressive target tracking  

NASA Astrophysics Data System (ADS)

Traditional approaches to persistent surveillance generate prodigious amounts of data, stressing storage, communication, and analysis systems. As such, they are well suited for compressed sensing (CS) concepts. Existing demonstrations of compressive target tracking have utilized time-sequences of random patterns, an approach that is sub-optimal for real world dynamic scenes. We have been investigating an alternative architecture that we term SCOUT-the Static Computational Optical Undersampled Tracker-which uses a pair of static masks and a defocused detector to acquire a small number of measurements in parallel. We will report on our working prototypes that have demonstrated successful target tracking at 16x compression.

Poon, Phillip K.; Townsend, Daniel; Wehrwein, Scott; Vera, Esteban M.; Stenner, Michael D.; Gehm, Michael E.



Celiac artery compression syndrome.  


Celiac artery compression syndrome is a rare disorder characterized by episodic abdominal pain and weight loss. It is the result of external compression of celiac artery by the median arcuate ligament. We present a case of celiac artery compression syndrome in a 57-year-old male with severe postprandial abdominal pain and 30-pound weight loss. The patient eventually responded well to surgical division of the median arcuate ligament by laparoscopy. PMID:23653867

Muqeetadnan, Mohammed; Amer, Syed; Rahman, Ambreen; Nusrat, Salman; Hassan, Syed



On compressing encrypted data  

Microsoft Academic Search

When it is desired to transmit redundant data over an insecure and bandwidth-constrained channel, it is customary to first compress the data and then encrypt it. In this paper, we investigate the novelty of reversing the order of these steps, i.e., first encrypting and then compressing, without compromising either the compression efficiency or the information-theoretic security. Although counter-intuitive, we show

Mark Johnson; Prakash Ishwar; Vinod Prabhakaran; Daniel Schonberg; Kannan Ramchandran



Simulation of Drift-Compression for Heavy-Ion-Fusion  

SciTech Connect

Lengthwise compression of space-charge-dominated beams is needed to obtain the high input power required for heavy-ion fusion. The ''drift-compression'' scenario studied here first applies a head-to-tail velocity variation with the beam tail moving faster than the head. As the beam drifts, the longitudinal space-charge field slows compression, leaving the beam nearly monoenergetic as it enters the final-focus magnets. This paper presents initial work to model this compression scenario. Fluid and particle simulations are compared, and several strategies for setting up the compression schedule are discussed.

Sharp, W M; Barnard, J J; Grote, D P; Celata, C M; Yu, S S



Demonstration of the Feasibility of Radially Compressed Microbore HPLC Columns  

Microsoft Academic Search

This work involved the development of radially compressed, microbore high performance liquid chromatography (HPLC) columns. The design of the overall system and the column are described, and the problems associated with the design features are reported. Variables examined during the course of this work included the column material, column length, packing method, flow rate, radial compression pressure, and internal column

P. A. Hyldburg; C. M. Sparacino; J. W. Hines; C. D. Keller



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


Teleconference Memorandum - Weekly Update Telecon ...  

Center for Biologics Evaluation and Research (CBER)

... Teleconference Memorandum - Weekly Update Telecon, March 16, 2007. DEPARTMENT ... Research. Date\\Time: March 16, 2007. ... More results from


Compressive confocal microscopy  

Microsoft Academic Search

In this paper, a new framework for confocal microscopy based on the novel theory of compressive sensing is pro- posed. Unlike wide field microscopy or conventional parallel beam confocal imaging systems that use charge-coupled de- vices (CCD) as acquisition devices in addition to complex mechanical scanning system, the proposed compressive con- focal microscopy is a kind of parallel beam confocal

Peng Ye; José L. Paredes; Gonzalo R. Arce; Yuehao Wu; Caihua Chen; Dennis W. Prather



Compressibilities of tetramethyltetraselenafulvalene hexafluorophosphate  

SciTech Connect

Values of the lattice constants of tetramethyltetraselenafulvalene hexafluorophosphate at 3 kbar (room temperature) have been measured by x-ray methods and compressibilities have been determined. The needle direction (a axis) is reduced by approximately 0.5%/kbar while the normal directions are an order of magnitude less compressible.

Morosin, B.; Schirber, J.E.; Greene, R.L.; Engler, E.M.



Static compressive tracking  

Microsoft Academic Search

This paper presents the Static Computational Optical Undersampled Tracker (SCOUT), an architecture for compressive motion tracking systems. The architecture uses compressive sensing techniques to track moving targets at significantly higher resolution than the detector array, allowing for low cost, low weight design and a significant reduction in data storage and bandwidth requirements. Using two amplitude masks and a standard focal

D. J. Townsend; P. K. Poon; S. Wehrwein; T. Osman; A. V. Mariano; E. M. Vera; M. D. Stenner; M. E. Gehm



Compressed air energy storage  

Microsoft Academic Search

Compressed air energy storage (CAES) systems are being developed for peak load leveling applications by electric utilities. Energy is stored by compressing air in an underground reservoir; when power is required, the air is heated and expanded through a turbine-generator system. Several CAES plants are being designed, and construction of the first large scale plant will be completed late this

K. G. Vosburgh



Compressed air energy storage  

Microsoft Academic Search

Compressed air energy storage (CAES) systems are being developed for peak load leveling applications by electric utilities. Energy is stored by compressing air in an underground reservoir; when power is required, the air is heated and expanded through a turbine-generator system. Several CAES plants are being designed, and construction of the first large-scale plant will be completed late in 1977.

K. G. Vosburgh



Autosophy still image compression  

NASA Astrophysics Data System (ADS)

A new image compression format is being developed to replace the gif and tif formats for Internet image transmission. Based on the Autosophy information theory, the new format is especially suited to the Internet. Features include much higher compression ratios, improved resistance to the Internet's Quality of Service (QoS) problems, a universal hardware-independent communication format, and optional codebook encryption for secure communications. The all 16 bit data format allows the mixing of other Internet data types (including the live video, sound, text, and random bit files) within a universal communication protocol. Encoding speed is less than a second per image. Hardware chipsets are necessary for real-time encoding speed, but real-time retrieval can be achieved using software only. Conventional lossless image compression formats use the dynamically growing tree libraries of the LZW code. That yields minimal compression for small images and creates great sensitivity to transmission errors. The new image compression format, in contrast, uses a fixed pre-grown hyperspace pattern library. That provides much higher compression ratios, increased error resistance, and even optional encryption. The same algorithms can provide either lossless compression according to the Shannon theory or visually lossless compression according to the Autosophy theory.

Holtz, Klaus E.; Holtz, Eric S.; Kalienky, Diana



Compressed Media: A New Dimension of Compressed Speech.  

National Technical Information Service (NTIS)

Through the use of the Information Mapping and Information Blocking format, this paper discusses various means of increasing the information availability rate through compressed media. Techniques reviewed include: compressed speech, compressed media for i...

R. H. Hartjen



Aerodynamics inside a rapid compression machine  

SciTech Connect

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

Mittal, Gaurav; Sung, Chih-Jen [Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, OH 44106 (United States)



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



Training for Fitness reconsidering the 80-hour work week  

Microsoft Academic Search

134 ABSTRACT 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 \\

Catherine V. Caldicott; James W. Holsapple



Local compressibilities in crystals  

NASA Astrophysics Data System (ADS)

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

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



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



Dynamic cardiac compression improves contractile efficiency of the heart  

Microsoft Academic Search

The effect of dynamic cardiac compression on left ventricular contractile efficiency was assessed in terms of the pressure-volume relationship and myocardial oxygen consumption. In 11 excised cross-circulated dog hearts, the ventricle was directly compressed during systole (dynamic cardiac compression). Measurements for pressure-volume area (a measure of total mechanical energy), external work, and myocardial oxygen consumption were done before and during

Osamu Kawaguchi; Yoichi Goto; Yuichi Ohgoshi; Hitoshi Yaku; Mitsuya Murase; Hiroyuki Suga



Subdiffusion in random compressible flows.  


In this work, we study the diffusion of admixture particles in a one-dimensional velocity field given by a gradient of a random potential. This refers us to the case of random compressible flows, where previously only scaling estimates were available. We develop a general approach which allows to solve this problem analytically. With its help we derive the macroscopic transport equation and rigorously show in which cases transport can be subdiffusive. We find the Fourier-Laplace transform of the Green's function of this equation and prove that for some potential distributions it satisfies the subdiffusive equation with fractional derivative with respect to time. PMID:16089720

Chukbar, Konstantin; Zaburdaev, Vasily



Sandia Shock Compression Database.  

National Technical Information Service (NTIS)

An authoritative, updatable, and searchable bibliographic database whose topical area is shock compression is currently under development. The database is derived from published scientific articles and reports with current emphasis in the subareas of stre...

C. E. Anderson D. E. Grady J. C. Hokanson J. R. Asay J. S. Wilbeck



Visualizing tension and compression  

NASA Astrophysics Data System (ADS)

The use of everyday materials to support instruction in statics is discussed. Specifically, materials such as cardboard and string are used to demonstrate tension and compression in truss-bridge models.

Taylor, Joseph A.



Compressed Natural Gas.  

National Technical Information Service (NTIS)

The suitability of compressed natural gas (CNG) as an automotive fuel has been conclusively demonstrated, both overseas and in New Zealand. In addition, CNG has a number of operational advantages of great social, economic and environmental benefit. The ma...

J. P. West L. G. Brown



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.



Hybrid LZW compression  

NASA Astrophysics Data System (ADS)

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.



Orbiting Dynamic Compression Laboratory.  

National Technical Information Service (NTIS)

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 co...

T. J. Ahrens T. Vreeland P. Kasiraj B. Frisch



Shock compression of Wüstite  

Microsoft Academic Search

Hugoniot compression curve of wüstite (Fe1-xO) was studied up to 120 GPa using a double-stage light-gas gun. Pore-free polycrystalline wüstite was grown by the floating zone method and platelet specimens, typically 10 × 14 × 2 mm³, were prepared. The inclined mirror method was adopted to record the shock compression state and both the impedance matching solution and the free

T. Yagi; K. Fukuoka; H. Takei; Y. Syono



Shock compression of wüstite  

Microsoft Academic Search

Hugoniot compression curve of wüstite (Fe1-xO) was studied up to 120 GPa using a double-stage light-gas gun. Pore-free polycrystalline wütite was grown by the floating zone method and platelet specimens, typically 10×14×2 mm3, were prepared. The inclined mirror method was adopted to record the shock compression state and both the impedance matching solution and the free surface approximation were used

T. Yagi; K. Fukuoka; H. Takei; Y. Syono



Image Compression Terrain Simplification  

Microsoft Academic Search

We suggest a new terrain simplification algorithm which is based on known Digital Image Processing compres- sion methods (e.g. DCT, wavelets compression) that was specially adjusted to fit Digital Elevation Mod- els. DEM-images are terrains or elevation maps rep- resented as gray scale images. We investigate the spe- cial nature of such terrain-images and design a unique pre-compression process which

Boaz Ben-moshe; Liad Serruya; Ariel Shamir



Compressed Compact Suffix Arrays  

Microsoft Academic Search

\\u000a The compact suffix array (CSA) is a space-efficient full-text index, which is fast in practice to search for patterns in a static text. Compared to\\u000a other compressed suffix arrays (Grossi and Vitter, Sadakane, Ferragina and Manzini), the CSA is significantly larger (2.7 times the text size, as opposed\\u000a to 0.6–0.8 of compressed suffix arrays). The space of the CSA includes

Veli Mäkinen; Gonzalo Navarro



When Indexing Equals Compression: Experiments with Compressing Sux Arrays and Applications  

Microsoft Academic Search

We report on a new and improved version of high-order entropy-compressed sux arrays, which has theoretical performance guarantees comparable to previous work, yet represents an improvement in practice. Our experiments indicate that the resulting text index oers state-of- the-art compression. In particular, we require roughly 20% of the original text size|without requiring a separate instance of the text|and support fast

Roberto Grossi; Ankur Guptay; Jerey Scott


When indexing equals compression: Experiments with compressing suffix arrays and applications  

Microsoft Academic Search

We report on a new experimental analysis of high-order entropy-compressed suffix arrays, which retains the theoretical performance of previous work and represents an improvement in practice. Our experiments indicate that the resulting text index offers state-of-the-art compression. In particular, we require roughly 20% of the original text size—without requiring a separate instance of the text. We can additionally use a

Luca Foschini; Roberto Grossi; Ankur Gupta; Jeffrey Scott Vitter



When indexing equals compression: experiments with compressing suffix arrays and applications  

Microsoft Academic Search

We report on a new and improved version of high-order entropy-compressed suffix arrays, which has theoretical performance guarantees similar to those in our earlier work [16], yet represents an improvement in practice. Our experiments indicate that the resulting text index offers state-of-the-art compression. In particular, we require roughly 20% of the original text size---without requiring a separate instance of the

Roberto Grossi; Ankur Gupta; Jeffrey Scott Vitter



75 FR 20885 - National Park Week, 2010  

Federal Register 2010, 2011, 2012, 2013

...Proclamation 8498--National Park Week, 2010 Proclamation 8499--National Crime Victims' Rights Week, 2010 Proclamation 8500--National Volunteer Week, 2010 Proclamation 8501--National Day of Service and...



"Creative" Work Schedules.  

ERIC Educational Resources Information Center

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

Blai, Boris


Compression Aware Physical Database Design  

Microsoft Academic Search

Modern RDBMSs support the ability to compress data using methods such as null suppression and dictionary encoding. Data compression offers the promise of significantly reducing storage requirements and improving I\\/O performance for decision support queries. However, compression can also slow down update and query performance due to the CPU costs of compression and decompression. In this paper, we study how

Hideaki Kimura; Vivek Narasayya; Manoj Syamala



Superplastic boronizing of duplex stainless steel under dual compression method  

Microsoft Academic Search

In this work, SPB of duplex stainless steel (DSS) under compression method is studied with the objective to produce ultra hard and thick boronized layer using minimal amount of boron powder and at a much faster boronizing time as compared to the conventional process. SPB is conducted under dual compression methods. In the first method DSS is boronized using a

I. Jauhari; H. A. M. Yusof; R. Saidan



Context Tables: A Tool for Describing Text Compression Algorithms  

Microsoft Academic Search

This paper introduces the notion of a context table, which is a common basis for describing and analyzing text compression algorithms. A context table stores all substrings in a text as their lexicographic orders. Examples of compression algorithms described in terms of context table concepts include LZ77 and the block-sorting algorithm. Since these algorithms are designed to work with an

Hidetoshi Yokoo



Aseptic Bone Necrosis Survey in Compressed Air Workers.  

National Technical Information Service (NTIS)

Investigation to determine by x-ray the incidence of bone or joint injury among compressed air workers reveals that Washington State safety standards for compressed air work appear to have prevented disability due to osteoarthritis up to 34 pounds per squ...

J. L. Sealey



Simulation of a solar powered vapor compression desalination system (SPRVCD)  

Microsoft Academic Search

This article is concerned with the analysis of a solar powered vapor compression desalination system. It consists of three loops, namely, a collector loop, a power loop, and a vapor compression desalination loop. The system is operated by a parabolic collector trough of concentration 4 and R11 as a working fluid with an optimum boiler firing temperature of 410°K. A

K. A. Fathalah; M. A. Darwish; S. E. Aly



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



Physical Property Measurements: Unconfined Compressive Strength (UCS)  

NSDL National Science Digital Library

This site, by the Colorado School of Mines, addresses the properties of a measurement technique called unconfined compression strength (UCS). Along with defining the technique, the website shows different experiments, pictures and diagrams associated with UCS. This well organized work will be a valuable asset for any geology or engineering classroom.

Ozdemir, Levent



Data compression and prediction in neural networks  

Microsoft Academic Search

We study the relationship between data compression and prediction in single-layer neural networks of limited complexity. Quantifying the intuitive notion of Occam's razor using Rissanen's minimum complexity framework, we investigate the model-selection criterion advocated by this principle. While we find that the criterion works well for large sample sizes (as it must for consistency), the behavior for finite sample sizes

Ronny Meir; Jose F. Fontanari



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.


A biomechanical comparison of shape memory compression staples and mechanical compression staples: compression or distraction?  


Compression staples are a popular form of fixation for osteotomy and arthrodesis. "Mechanical compression" or "shape memory" designs are commercially available. We performed a biomechanical study comparing these designs. A load cell measured compression across a simulated fusion site. The two designs available were tested and compared. The effect of altering staple limb length was also assessed. The limbs of all mechanical compression staples diverged causing inconsistent compression and distraction. Shape memory staples all achieved consistent compression across the fusion site with significantly greater maximum force when compared to mechanical compression staples (P < 0.001). Staple limb length did not appear to alter compression force generated. Mechanical compression staples cause a distractive force, and we therefore suggest alternate forms of fixation for arthrodesis. Shape memory staples do provide compression and may be suitable for arthrodesis and osteotomy. PMID:19690834

Farr, David; Karim, Amer; Lutz, Michael; Calder, James



NASA Workshop Transforms Teachers Into Glaciologists For a Week  

NASA Website

NASA's week-long History of Winter workshop allows elementary and secondary science teachers to work hand-in-glove with glaciologists while learning about research tools and techniques used in field studies of snow and ice.


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...



Adult Learners' Week in Switzerland.  

ERIC Educational Resources Information Center

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

Jermann, Ruth



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



Data compression and prediction in neural networks  

NASA Astrophysics Data System (ADS)

We study the relationship between data compression and prediction in single-layer neural networks of limited complexity. Quantifying the intuitive notion of Occam's razor using Rissanen's minimum complexity framework, we investigate the model-selection criterion advocated by this principle. While we find that the criterion works well for large sample sizes (as it must for consistency), the behavior for finite sample sizes is rather complex, depending intricately on the relationship between the complexity of the hypothesis space and the target space. We also show that the limited networks studied perform efficient data compression, even in the error full regime. Research supported in part by the CNPq.

Meir, Ronny; Fontanari, Jose F.



Isentropic compression of argon  

SciTech Connect

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

Veeser, L.R.; Ekdahl, C.A.; Oona, H. [and others



Mechanics of the compression wood response: I. Preliminary analyses.  


Righting of two tilted white pine (Pinus strobus L.) stem leaders by compression wood formation was followed for 16 weeks. The natural curves and three deflection curves under added end loads were determined from weekly field photographs. Data for self-loading and cross sectional diameters were interpolated from original estimated and final measurements. A mechanical-mathematical model was developed to predict curves under zero gravity for each stem each week. The model estimated stiffness of the leaders independently for each week, and the stiffnesses were consistent throughout the experiment. A second model was developed to simulate the deflection curves assumed when the zero gravity curves were subjected to different end loads. These predicted curves were nearly identical to the observed curves from the photographs, thus verifying the assumptions in the first model. Data from this study will be used to investigate the mechanical aspects of compression wood induction and action as the stem is bent upward toward the vertical. PMID:16657504

Archer, R R; Wilson, B F



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



Electronic compressibility of bilayer graphene  

NASA Astrophysics Data System (ADS)

We have recently measured the electronic compressibility of bilayer graphene [1], allowing exploration of the thermodynamic density of states as a function of applied electric and magnetic fields. Utilizing dual-gated field-effect devices, we can independently vary both the carrier density and the size of the tunable band gap. An oscillating voltage applied to a back gate generates corresponding signals in the top gate via electric fields lines which penetrate the graphene, thereby allowing a direct measurement of the inverse compressibility, K-1, of the bilayer [2]. We have mapped K-1, which is proportional to the inverse density of states, as a function of the top and back gate voltages in zero and finite magnetic field. A sharp increase in K-1 near zero density is observed with increasing electric field strength, signaling the controlled opening of a band gap. At high magnetic fields, broad Landau level (LL) oscillations are observed, directly revealing the doubled degeneracy of the lowest LL and allowing for a determination of the disorder broadening of the levels. We compare our results to tight-binding calculations of the bilayer band structure, and to recent theoretical studies of the compressibility of bilayer graphene. Together, these clearly illustrate the unusual hyperbolic nature of the low energy band structure, reveal a sizeable electron-hole asymmetry, and suggest that many-body interactions play only a small role in bilayer-on-substrate devices. This work is a collaboration with J. P. Eisenstein of Caltech, and is supported by the NSF under Grant No. DMR-0552270 and the DOE under Grant No. DE-FG03-99ER45766. [4pt] [1] E. A. Henriksen and J. P Eisenstein, Phys. Rev. B 82, 041412(R) (2010). [0pt] [2] J. P. Eisenstein, L. N. Pfeiffer, and K. W. West, Phys. Rev. Lett. 68, 674 (1992); Phys. Rev. B 50, 1760 (1994).

Henriksen, Erik



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


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



Compressible and incompressible fluids  

Microsoft Academic Search

The considered equations of compressible ideal fluid flow in appropriate nondimensional form are a hyperbolic system in four variables, related to density and fluid velocity. The Euler equations of incompressible fluid flow are a distinctly different system of four equations in four unknowns. Qualitative and quantitative properties of a specific limiting process are developed. The new results include more general

S. Klainerman; Andrew Majda



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



Gas compression infrared generator  

SciTech Connect

A molecular gas is compressed in a quasi-adiabatic manner to produce pulsed radiation during each compressor cycle when the pressure and temperature are sufficiently high, and part of the energy is recovered during the expansion phase, as defined in U.S. Pat. No. 3,751,666; characterized by use of a cylinder with a reciprocating piston as a compressor.

Hug, W.F.



The Compressed Video Experience.  

ERIC Educational Resources Information Center

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

Weber, John


Compressed Beamforming in Ultrasound Imaging  

NASA Astrophysics Data System (ADS)

Emerging sonography techniques often require increasing the number of transducer elements involved in the imaging process. Consequently, larger amounts of data must be acquired and processed. The significant growth in the amounts of data affects both machinery size and power consumption. Within the classical sampling framework, state of the art systems reduce processing rates by exploiting the bandpass bandwidth of the detected signals. It has been recently shown, that a much more significant sample-rate reduction may be obtained, by treating ultrasound signals within the Finite Rate of Innovation framework. These ideas follow the spirit of Xampling, which combines classic methods from sampling theory with recent developments in Compressed Sensing. Applying such low-rate sampling schemes to individual transducer elements, which detect energy reflected from biological tissues, is limited by the noisy nature of the signals. This often results in erroneous parameter extraction, bringing forward the need to enhance the SNR of the low-rate samples. In our work, we achieve SNR enhancement, by beamforming the sub-Nyquist samples obtained from multiple elements. We refer to this process as "compressed beamforming". Applying it to cardiac ultrasound data, we successfully image macroscopic perturbations, while achieving a nearly eight-fold reduction in sample-rate, compared to standard techniques.

Wagner, Noam; Eldar, Yonina C.; Friedman, Zvi



Effects of compression on the sound absorption of porous materials with an elastic frame  

Microsoft Academic Search

The absorption characteristics of a porous material are well known to vary during compression. The transfer matrix method is applied with an elastic frame to explore the effect of compression on absorption properties. In this work, the materials are treated as elastic rather than being made of rigid models. The absorption coefficients of the uncompressed and compressed porous material are

Chao-Nan Wang; Yan-Min Kuo; Shih-Kai Chen



Compressive Flow of Viscoelastic Materials.  

National Technical Information Service (NTIS)

The compressive flow of viscoelastic materials between two parallel flat disks under a constant load has been investigated analytically, numerically, and experimentally. This process simulates a number of compression molding and lubrication experiments; t...

S. J. Lee



Energy Transfer in Compressible Turbulence.  

National Technical Information Service (NTIS)

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-...

F. Bataille Y. Zhou J. Bertoglio



fpack: FITS Image Compression Program  

NASA Astrophysics Data System (ADS)

fpack is a utility program for optimally compressing images in the FITS data format. The associated funpack program will restore the compressed file back to its original state. These programs may be run from the host operating system command line and are analogous to the gzip and gunzip utility programs, except that they are specifically optimized for FITS format images and offer a wider choice of compression options. fpack uses the tiled image compression convention for storing the compressed images. This convention can in principle support any number of of different compression algorithms; currently GZIP, Rice, Hcompress, and the IRAF pixel list compression algorithms have been implemented. The main advantages of fpack compared to the commonly used technique of externally compressing the whole FITS file with gzip are: 1. It is generally faster and offers better compression than gzip. 2. The FITS header keywords remain uncompressed for fast access. 3. Each HDU of a multi-extension FITS file is compressed separately, so it is not necessary to uncompress the entire file to read a single image in a multi-extension file. 4. Dividing the image into tiles before compression enables faster access to small subsections of the image. 5. The compressed image is itself a valid FITS file and can be manipulated by other general FITS utility software. 6. Lossy compression can be used for much higher compression in cases where it is not necessary to exactly preserve the original image. 7. The CHECKSUM keywords are automatically updated to help verify the integrity of the files. 8. Software that supports the tiled image compression technique can directly read and write the FITS images in their compressed form.

Seaman, Rob; Pence, William; White, Rick



Shockless compression of z-cut quartz to 7 GPa  

NASA Astrophysics Data System (ADS)

Using a recently developed compact pulsed power generator (CPPG), z-cut quartz samples were subjected to shockless uniaxial strain compression to 7 GPa peak stress. Over this stress range, the behavior of z-cut quartz under shock compression [J. Appl. Phys. 88, 5671 (2000)] is nonlinear elastic and in good agreement with predictions based on the measured values of the second and third order elastic constants. In-material and free surface velocities were measured in the present work and analyzed, using a Lagrangian analysis, to provide a continuous loading curve for z-cut quartz. The wavelet speed-particle velocity (Cu-u, where Cu?(?h/?t)u) results were somewhat sensitive to the CPPG panel design details, as well as the velocity data acquisition and reduction techniques. Improvements to provide optimal data were discussed and used to provide accurate longitudinal stress-density response to 7 GPa (6% density compression). The Cu-u curves, a more stringent measure of the material response to nonlinear compression, were within 0.6% of the values predicted using shock compression measurements. This excellent agreement demonstrates that the shockless compression response of quartz is indistinguishable from the shock response in the nonlinear elastic regime and provides a good foundation for comparing the inelastic response of solids under shockless and shock compression. The present work also demonstrated the use of the CPPG as a laboratory capability for examining the shockless compression of materials.

Jaglinski, T.; Lalone, B. M.; Bakeman, C. J.; Gupta, Y. M.



High dynamic range texture compression  

Microsoft Academic Search

We present a novel compression scheme for high dynamic range textures, targeted for hardware implementation. Our method encodes images at a constant 8 bits per pixel, for a compression ratio of 6:1. We demonstrate that our method achieves good visual fidelity, surpassing DXTC texture compression of RGBE data which is the most practical method on existing graphics hardware. The decoding

Kimmo Roimela; Tomi Aarnio; Joonas Itäranta



High dynamic range texture compression  

Microsoft Academic Search

We present a novel compression scheme for high dynamic range textures, targeted for hardware implementation. Our method en- codes images at a constant 8 bits per pixel, for a compression ratio of 6:1. We demonstrate that our method achieves good visual fi- delity, surpassing DXTC texture compression of RGBE data which is the most practical method on existing graphics hardware.

Kimmo Roimela; Tomi Aarnio; Joonas Itäranta



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



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



Compression Experiments with AVHRR Data  

Microsoft Academic Search

This paper describes several data compression approaches for producing browse data from AVHRR data, and evaluates these approaches qualitatively and quantitatively. They include a hierarchical data compression scheme based on progressively finer image segmentations, and various vector quantization approaches. They are evaluated in terms of compression ratio (or data rate), computational requirements, and the image and analysis errors introduced due

James C. Tilton; D. Han; Mareboyana Manohar



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



77 FR 22177 - National Volunteer Week, 2012  

Federal Register 2010, 2011, 2012, 2013

...Proclamation 8797--National Volunteer Week, 2012 Proclamation 8798--Pan American Day and Pan American Week, 2012 Proclamation 8799--National Former...8797 of April 9, 2012 National Volunteer Week, 2012 By the President of the United...



75 FR 70999 - National Entrepreneurship Week, 2010  

Federal Register 2010, 2011, 2012, 2013

...Proclamation 8600--National Entrepreneurship Week, 2010 Proclamation 8601--America Recycles...November 15, 2010 National Entrepreneurship Week, 2010 By the President of the United States...reach. During National Entrepreneurship Week, we renew our commitment to...



76 FR 63801 - Fire Prevention Week, 2011  

Federal Register 2010, 2011, 2012, 2013

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76 FR 72601 - National Family Week, 2011  

Federal Register 2010, 2011, 2012, 2013

...Proclamation 8756--National Family Week, 2011 Proclamation 8757--National Farm-City Week, 2011 Proclamation 8758--National Child's...8756 of November 18, 2011 National Family Week, 2011 By the President of the United...



76 FR 71445 - American Education Week, 2011  

Federal Register 2010, 2011, 2012, 2013

...Proclamation 8753--American Education Week, 2011 Presidential Documents Federal Register...of November 14, 2011 American Education Week, 2011 By the President of the United States...thriving democracy. During American Education Week, we acknowledge the central role...



78 FR 44867 - Captive Nations Week, 2013  

Federal Register 2010, 2011, 2012, 2013

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76 FR 43107 - Captive Nations Week, 2011  

Federal Register 2010, 2011, 2012, 2013

...Proclamation 8692--Captive Nations Week, 2011 Presidential Documents Federal Register...8692 of July 15, 2011 Captive Nations Week, 2011 By the President of the United States...shaped our world. During Captive Nations Week, we remember the men and women...



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



Compression gastrointestinal anastomosis.  


The creation of anastomoses between various parts of the GI tract is a major task in the daily practice of oncological, reconstructive and transplant surgery. The most widely used anastomosing techniques today involve the use of sutures or metal titanium staples. Both techniques involve foreign material penetrating the tissue and evoking localized inflammatory response, tissue injury and breaking of mucosal barriers that may facilitate bacterial growth within the anastomotic line, increasing the propensity to anastomotic-related morbidity. Different types of compression devices were successfully used clinically in the past. The history and evolving characteristics of this technology is reviewed. Nitinol-based solutions for the creation of compression anastomosis are evaluated as a possible potential for revolutionary impact on the current surgical methods and anastomosing technology in the alimentary tract and beyond. PMID:18035948

Kopelman, Doron; Hatoum, Ossama A; Kimmel, Boaz; Monassevitch, Leonid; Nir, Yael; Lelcuk, Shlomo; Rabau, Micha; Szold, Amir



Compression and entrapment neuropathies.  


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



Compressed air energy storage  

SciTech Connect

This article discusses compressed air energy storage (CAES). CAES is the first storage technology with an attractive price for storing large quantities of energy. This is especially so in flat country where hydroelectric pumped power plants cannot be developed. There are many favorable geological formations for CAES's use. About three-quarters of the United States has sites. CAES plants are expected to have a 30-year life and store off-peak energy with more than 80 percent efficiency.

Not Available



Static compressive tracking.  


This paper presents the Static Computational Optical Undersampled Tracker (SCOUT), an architecture for compressive motion tracking systems. The architecture uses compressive sensing techniques to track moving targets at significantly higher resolution than the detector array, allowing for low cost, low weight design and a significant reduction in data storage and bandwidth requirements. Using two amplitude masks and a standard focal plane array, the system captures many projections simultaneously, avoiding the need for time-sequential measurements of a single scene. Scenes with few moving targets on static backgrounds have frame differences that can be reconstructed using sparse signal reconstruction techniques in order to track moving targets. Simulations demonstrate theoretical performance and help to inform the choice of design parameters. We use the coherence parameter of the system matrix as an efficient predictor of reconstruction error to avoid performing computationally intensive reconstructions over the entire design space. An experimental SCOUT system demonstrates excellent reconstruction performance with 16X compression tracking movers on scenes with zero and nonzero backgrounds. PMID:23037240

Townsend, D J; Poon, P K; Wehrwein, S; Osman, T; Mariano, A V; Vera, E M; Stenner, M D; Gehm, M E



Compression of multiwall microbubbles  

NASA Astrophysics Data System (ADS)

Optical monitoring of structural transformations and transport processes is prohibited if the objects to be studied are bulky and/or non-transparent. This paper is focused on the development of a microbbuble platform for acoustic imaging of heterogeneous media under harsh environmental conditions including high pressure (<500 atm), temperature (<100 C), and salinity (<10 wt%). We have studied the compression behavior of gas-filled microbubbles composed of multiple layers of surfactants and stabilizers. Upon hydrostatic compression, these bubbles undergo significant (up to 100x) changes in volume, which are completely reversible. Under repeated compression/expansion cycles, the pressure-volume P(V) characteristic of these microbubbles deviate from ideal-gas-law predictions. A theoretical model was developed to explain the observed deviations through contributions of shell elasticity and gas effusion. In addition, some of the microbubbles undergo peculiar buckling/smoothing transitions exhibiting intermittent formation of facetted structures, which suggest a solid-like nature of the pressurized shell. Preliminary studies illustrate that these pressure-resistant microbubbles maintain their mechanical stability and acoustic response at pressures greater than 1000 psi.

Lebedeva, Natalia; Moore, Sam; Dobrynin, Andrey; Rubinstein, Michael; Sheiko, Sergei



Education Week on the Web  

NSDL National Science Digital Library

"America's Education Newspaper of Record" now publishes a Web edition. The full text of the print version is available online, as well as the monthly Teacher Magazine. The site is in final testing, so not all areas are fully functional; however, the depth of material already available makes it worthwhile to check out now. Content is divided into general categories: This Week's News offers headlines in education; In Context provides background on issues, organizations and resources relating to education; Teacher Magazine is the online version of the popular print publication; and Election Watch investigates the future of public education under the two major-party Presidential candidates, as well as important issues in the election. Searching of 15 years of archived content will be available soon, and will be free for a limited time (fee information is not yet available). The site is polished graphically, making effective and unobtrusive use of frames and images.



Educators' Guide to Ally Week  

ERIC Educational Resources Information Center

|An ally is an individual who speaks out and stands up for a person or group that is targeted and/or discriminated against. An ally works to end oppression by supporting and advocating for people who are stigmatized, or treated unfairly because of who they are. In this context, Allies are referred to as people who do not identify as LGBT…

Gay, Lesbian and Straight Education Network (GLSEN), 2010



Random-Accessible Compressed Triangle Meshes  

Microsoft Academic Search

Abstract—With the exponential growth in size of geometric data, it is becoming increasingly important to make effective use of multilevel caches, limited disk storage, and bandwidth. As a result, recent work in the visualization community has focused either on designing,sequential access compression schemes or on producing,cache-coherent,layouts of (uncompressed),meshes,for random access. Unfortunately combining,these two strategies is challenging,as they fundamentally,assume,conflicting modes,of data

Sung-eui Yoon; Peter Lindstrom



Compressibility effects in shaped charge jet penetration  

Microsoft Academic Search

Among other hypotheses, the classical theory of high-speed penetration assumes the incompressibility of both the projectile and target. Employing a simple Murnaghan equation of state, we show here that direct compressibility effects (pv-work) on penetration depth are at most on the order of 10–15% for projectile speeds as high as 104 ms?1. Our results agree closely with similar results by

B. S. Haugstad





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

Branin, T.G.



Composites with improved compressive properties. Final report  

SciTech Connect

A two year program was initiated on October 1, 1990 to pursue new approaches on improving the compressive properties of polymer based composites. This included work directed at new kinds of reinforcing agents, improved matrices and on the fiber matrix interface. A number of significant breakthroughs were achieved as a result of this study. In the case of the polymer matrix studies sufficient progress was made to justify additional funding and time extensions.

Economy, J.



Polymeric foam behavior under dynamic compressive loading  

Microsoft Academic Search

Polymeric foams are commonly used in many impact-absorbing applications and thermal-acoustic insulated devices. To improve their mechanical performances, these structures have to be modeled. Constitutive equations (for their macroscopic behavior) have to be identified and then determined by appropriate tests.Tests were carried out on polypropylene foams under high strain rate compression. In this work, the material behaviour has been determined

P. Viot; F. Beani; J.-L. Lataillade



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



Compressibility study of quaternary phospholipid blend monolayers.  


The mechanical properties of liposome membranes are strongly dependent on type and ratio of lipid compounds, which can have important role in drug targeting and release processes when liposome is used as drug carrier. In this work we have used Brewster's angle microscopy to monitor the lateral compression process of lipid monolayers containing as helper lipids either distearoyl phosphatidylethanolamine (DSPE) or dioleoyl phophatidylethanolamine (DOPE) molecules on the Langmuir trough. The compressibility coefficient was determined for lipid blend monolayers containing the helper lipids above, cholesterol, distearoyl phosphatidylcholine (DSPC) and pegylated-DSPE at room temperature. Two variables, the cholesterol fraction and the ratio ? between the helper lipid (either DSPE or DOPE) and the reference lipid DSPC, were studied by multivariate analysis to evaluate their impact on the compressibility coefficient of the monolayers. The cholesterol level was found to be the most significant variable for DSPE blends while the ratio ? was the most significant one for DOPE blend monolayers. It was also found that these two variables can exhibit positive interaction and the same compressibility value can be obtained with different blend compositions. PMID:21397464

Cavalcanti, Leide P; Tho, Ingunn; Konovalov, Oleg; Fossheim, Sigrid; Brandl, Martin



Effects of compression on language evolution.  


For many adaptive complex systems information about the environment is not simply recorded in a look-up table, but is rather encoded in a theory, schema, or model, which compresses information. The grammar of a language can be viewed as such a schema or theory. In a prior study [Teal et al., 1999] we proposed several conjectures about the learning and evolution of language that should follow from these observations: (C1) compression aids in generalization; (C2) compression occurs more easily in a "smooth," as opposed to a "rugged," problem space: and (C3) constraints from compression make it likely that natural languages evolve towards smooth string spaces. This previous work found general, if not complete support for these three conjectures. Here we build on that study to clarify the relationship between Minimum Description Length (MDL) and error in our model and examine evolution of certain languages in more detail. Our results suggest a fourth conjecture: that all else being equal, (C4) more complex languages change more rapidly during evolution. PMID:10953250

Teal, T K; Taylor, C E



Random-accessible compressed triangle meshes.  


With the exponential growth in size of geometric data, it is becoming increasingly important to make effective use of multilevel caches, limited disk storage, and bandwidth. As a result, recent work in the visualization community has focused either on designing sequential access compression schemes or on producing cache-coherent layouts of (uncompressed) meshes for random access. Unfortunately combining these two strategies is challenging as they fundamentally assume conflicting modes of data access. In this paper, we propose a novel order-preserving compression method that supports transparent random access to compressed triangle meshes. Our decompression method selectively fetches from disk, decodes, and caches in memory requested parts of a mesh. We also provide a general mesh access API for seamless mesh traversal and incidence queries. While the method imposes no particular mesh layout, it is especially suitable for cache-oblivious layouts, which minimize the number of decompression I/O requests and provide high cache utilization during access to decompressed, in-memory portions of the mesh. Moreover, the transparency of our scheme enables improved performance without the need for application code changes. We achieve compression rates on the order of 20:1 and significantly improved I/O performance due to reduced data transfer. To demonstrate the benefits of our method, we implement two common applications as benchmarks. By using cache-oblivious layouts for the input models, we observe 2?6 times overall speedup compared to using uncompressed meshes. PMID:17968107

Yoon, Sung-Eui; Lindstrom, Peter


Compression machine cavity control  

NASA Astrophysics Data System (ADS)

A system design that uses closed loop control of the hydraulic system of a compression transfer press (used to make filled elastomer parts) has resulted in improved accuracy and repeatability in the speed and pressure control segments during the critical forming stages before part cure. The design uses a microprocessor to supply set points and timing functions to the control system. The cascade control system consists of a specially designed outer loop controller that feeds set point information to the inner loop valve controller. Presented are the final hardware and software architectures for this design, as well as a report on system performance.

Floersch, R. H.



Beamforming using compressive sensing.  


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



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.



Application of compressed sensing to the simulation of atomic systems  

PubMed Central

Compressed sensing is a method that allows a significant reduction in the number of samples required for accurate measurements in many applications in experimental sciences and engineering. In this work, we show that compressed sensing can also be used to speed up numerical simulations. We apply compressed sensing to extract information from the real-time simulation of atomic and molecular systems, including electronic and nuclear dynamics. We find that, compared to the standard discrete Fourier transform approach, for the calculation of vibrational and optical spectra the total propagation time, and hence the computational cost, can be reduced by approximately a factor of five.

Andrade, Xavier; Sanders, Jacob N.; Aspuru-Guzik, Alan



Particle-size Effect on the Compressibility of Nanocrystalline Germanium  

NASA Astrophysics Data System (ADS)

We have investigated the particle size effect on the compressibility of nano crystalline Germanium phase-I in pressure range of 0-15 GPa. In the present work, the Tait's equation of state (EOS) has been modified to predict the high pressure behaviour of nano crystalline Germanium of three different particle sizes 100 nm, 49 nm and 13 nm along with its bulk modulus counterpart. Our results on the study of compressibility show that nano size samples are less compressible than bulk materials which are in agreement with the Hall-Petch effect.

Pandya, Tushar C.; Shaikh, Aasim I.; Bhatt, Apoorva D.



Characterization of carbon nanotube fiber compressive properties using tensile recoil measurement.  


The tensile properties of carbon nanotube (CNT) fibers have been widely studied. However, the knowledge of their compressive properties is still lacking. In this work, the compressive properties of both pure CNT fibers and epoxy infiltrated CNT fibers were studied using the tensile recoil measurement. The compressive strengths were obtained as 416 and 573 MPa for pure CNT fibers and CNT-epoxy composite fibers, respectively. In addition, microscopic analysis of the fiber surface morphologies revealed that the principal recoil compressive failure mode of pure CNT fiber was kinking, while the CNT-epoxy composite fibers exhibited a failure mode in bending with combined tensile and compressive failure morphologies. The effect of resin infiltration on CNT fiber compressive properties, including the compressive strength and the deformation mode, is discussed. This work expands the knowledge base of the overall mechanical properties of CNT fibers, which are essential for their application in multifunctional composites. PMID:22494330

Zu, Mei; Lu, Weibang; Li, Qing-Wen; Zhu, Yuntian; Wang, Guojian; Chou, Tsu-Wei



Energy transfer in compressible turbulence  

NASA Astrophysics Data System (ADS)

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



Comparison of neuropathic pain induced by the application of normal and mechanically compressed nucleus pulposus to lumbar nerve roots in the rat  

Microsoft Academic Search

We studied whether applying nucleus pulposus tissue, obtained from tail intervertebral discs that had been subjected to chronic mechanical compression, to the lumbar nerve roots produces hyperalgesia, which is thought to be a pain-related behavior in the rat. An Ilizarov-type apparatus was used for immobilization and chronically applied compression of the rat tail for eight weeks. Three weeks after application

Mamoru Kawakami; Hiroshi Hashizume; Hideto Nishi; Takuji Matsumoto; Tetsuya Tamaki; Koichi Kuribayashi



Binary compressed imaging.  


Compressed sensing can substantially reduce the number of samples required for conventional signal acquisition at the expense of an additional reconstruction procedure. It also provides robust reconstruction when using quantized measurements, including in the one-bit setting. In this paper, our goal is to design a framework for binary compressed sensing that is adapted to images. Accordingly, we propose an acquisition and reconstruction approach that complies with the high dimensionality of image data and that provides reconstructions of satisfactory visual quality. Our forward model describes data acquisition and follows physical principles. It entails a series of random convolutions performed optically followed by sampling and binary thresholding. The binary samples that are obtained can be either measured or ignored according to predefined functions. Based on these measurements, we then express our reconstruction problem as the minimization of a compound convex cost that enforces the consistency of the solution with the available binary data under total-variation regularization. Finally, we derive an efficient reconstruction algorithm relying on convex-optimization principles. We conduct several experiments on standard images and demonstrate the practical interest of our approach. PMID:23193233

Bourquard, Aurélien; Unser, Michael



Perifoveal spatial compression.  


We report a strong compression of space around a visual anchor presented in the near visual periphery (<5°). While subjects kept fixation, a salient visual stimulus (from now on referred to as "anchor") was presented, followed by a brief whole-field mask. At various times around mask onset a probe dot was flashed. Subjects estimated the position of the probe dot in relation to a subsequently presented comparison bar. The probe dot location was perceived nearly veridically when presented long before or after mask onset. However, when the probe dot was presented simultaneously with the mask it appeared shifted toward the anchor by as much as 50% of their separation. The anchor had to appear briefly before mask onset to attract the probe dot. No compression occurred when the anchor was presented long before or after the mask. When the probe dot and anchor were presented with similar brief duration, the more peripheral stimulus always shifted toward the more foveal stimulus independently of their temporal order. We hypothesize that the attraction might be explained by the summation of the neural activity distributions of probe and anchor. PMID:23608343

Zimmermann, Eckart; Fink, Gereon; Cavanagh, Patrick



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



Shock compression of precompressed deuterium  

SciTech Connect

Here we report quasi-isentropic dynamic compression and thermodynamic characterization of solid, precompressed deuterium over an ultrafast time scale (< 100 ps) and a microscopic length scale (< 1 {micro}m). We further report a fast transition in shock wave compressed solid deuterium that is consistent with the ramp to shock transition, with a time scale of less than 10 ps. These results suggest that high-density dynamic compression of hydrogen may be possible on microscopic length scales.

Armstrong, M R; Crowhurst, J C; Zaug, J M; Bastea, S; Goncharov, A F; Militzer, B



Grid turbulence in compressible flow  

NASA Astrophysics Data System (ADS)

This paper describes an experimental investigation of the effects of mean compressibility on the structure and the decay characteristics of grid turbulence. The experiments comprise laser Doppler velocimetry measurements of an approximately homogeneous, isotropic turbulence field in subsonic compressible flow, with the Mach number ranging from 0.15 to 0.7. The results reveal that the turbulence intensity and decay characteristics are influenced by mean compressibility. Experience with the high subsonic and supersonic regimes is also reported.

Zwart, P. J.; Budwig, R.; Tavoularis, S.


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



Error-resilient intelligent compression of SAR imagery  

Microsoft Academic Search

In the present work, we propose a system for error-resilient coding of synthetic aperture radar imagery, whereby regions of interest and background information are coded independently of each other. A multiresolution, constant-false-alarm-rate (CFAR) detection scheme is utilized to discriminate between target regions and natural clutter. Based upon the detected target regions, we apply less compression to targets, and more compression

Robert J. Bonneau; Glen P. Abousleman



Investigation on wind energy-compressed air power system  

Microsoft Academic Search

Wind energy is a pollution free and renewable resource widely distributed over China. Aimed at protecting the environment\\u000a and enlarging application of wind energy, a new approach to application of wind energy by using compressed air power to some\\u000a extent instead of electricity put forward. This includes: explaining the working principles and characteristics of the wind\\u000a energy-compressed air power system;

Jia Guang-zheng; Wang Xuan-yin; Wu Gen-mao



Heat transfer effects in compressed air energy storage  

Microsoft Academic Search

Compressed-air energy-storage (CAES) systems are being developed for peak-load-leveling applications by electric utilities. Energy is stored by compressing air in an underground cavern; when power is required, the air is heated and expanded through a turbine-generator system. This work is part of a conceptual design of an 800-MW CAES system which uses a set of storage cavities mined in salt.

K. G. Vosburgh; P. G. Kosky



Magnetic compression laser driving circuit  


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)



A new efficient method for color image compression based on visual attention mechanism  

NASA Astrophysics Data System (ADS)

One of the key procedures in color image compression is to extract its region of interests (ROIs) and evaluate different compression ratios. A new non-uniform color image compression algorithm with high efficiency is proposed in this paper by using a biology-motivated selective attention model for the effective extraction of ROIs in natural images. When the ROIs have been extracted and labeled in the image, the subsequent work is to encode the ROIs and other regions with different compression ratios via popular JPEG algorithm. Furthermore, experiment results and quantitative and qualitative analysis in the paper show perfect performance when comparing with other traditional color image compression approaches.

Shao, Xiaoguang; Gao, Kun; Lv, Lily; Ni, Guoqiang



In Vivo Remodeling of Intervertebral Discs in Response to Short- and Long-Term Dynamic Compression  

PubMed Central

This study evaluated how dynamic compression induced changes in gene expression, tissue composition, and structural properties of the intervertebral disc using a rat tail model. We hypothesized that daily exposure to dynamic compression for short durations would result in anabolic remodeling with increased matrix protein expression and proteoglycan content, and that increased daily load exposure time and experiment duration would retain these changes but also accumulate changes representative of mild degeneration. Sprague-Dawley rats (n = 100) were instrumented with an Ilizarov-type device and divided into three dynamic compression (2 week-1.5 h/day, 2 week-8 h/day, 8 week-8 h/day at 1 MPa and 1 Hz) and two sham (2 week, 8 week) groups. Dynamic compression resulted in anabolic remodeling with increased matrix mRNA expression, minimal changes in catabolic genes or disc structure and stiffness, and increased glysosaminoglycans (GAG) content in the nucleus pulposus. Some accumulation of mild degeneration with 8 week-8 h included loss of annulus fibrosus GAG and disc height although 8-week shams also had loss of disc height, water content, and minor structural alterations. We conclude that dynamic compression is consistent with a notion of “healthy” loading that is able to maintain or promote matrix biosynthesis without substantially disrupting disc structural integrity. A slow accumulation of changes similar to human disc degeneration occurred when dynamic compression was applied for excessive durations, but this degenerative shift was mild when compared to static compression, bending, or other interventions that create greater structural disruption.

Wuertz, Karin; Godburn, Karolyn; MacLean, Jeffrey J.; Barbir, Ana; Donnelly, Justin Stinnett; Roughley, Peter J.; Alini, Mauro; Iatridis, James C.



Information optimal compressive sensing: static measurement design.  


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



Magnetic Compression in Gastrointestinal and Bilioenteric Anastomosis: How Much Force?  


Aim. The concept of compression alimentary anastomosis is well established. Recently, magnetic axial alignment pressures have been encompassed within such device constructs. We quantify the magnetic compression force and pressure required to successfully achieve gastrointestinal and bilioenteric anastomosis by in-depth interrogation of the reported literature. Methods. Reports of successful deployment and proof of anastomotic patency on survival were scrutinized to quantify the necessary dimensions and strengths of magnetic devices in (a) gastroenteral anastomosis in live porcine models and (b) bilioenteric anastomosis in the clinical setting. Using a calculatory tool developed for this work (magnetic force determination algorithm, MAGDA), ideal magnetic force and compression pressure were quantified from successful reports with regard to their variance by intermagnet separation. Results. Optimized ranges for both compression force and pressure were determined for successful porcine gastroenteral and clinical bilioenteric anastomoses. For gastroenteral anastomoses (porcine investigations), an optimized compression force between 2.55 and 3.57 kg at 2-mm intermagnet separation is recommended. The associated compression pressure should not exceed 60 N/cm(2). Successful bilioenteric anastomoses is best clinically achieved with intermagnet compression of 18 to 31 g and associated pressures between 1 and 3.5 N/mm(2) (at 2-mm intermagnet separation). Conclusion. The creation of magnetic compression anastomoses using permanent magnets demonstrates a remarkable resilience to variations in magnetic force and pressure exertion. However, inappropriate selection of compression characteristics and magnet dimensions may incur difficulties. Recommendations of this work and the availability of the free online tool ( may facilitate a factor of robustness in the design and refinement of future devices. PMID:23592733

Lambe, Tadhg; Ríordáin, Mícheál G Ó; Cahill, Ronan A; Cantillon-Murphy, Pádraig



Tissue engineering of cartilage using a mechanobioreactor exerting simultaneous mechanical shear and compression to simulate the rolling action of articular joints.  


The effect of dynamic mechanical shear and compression on the synthesis of human tissue-engineered cartilage was investigated using a mechanobioreactor capable of simulating the rolling action of articular joints in a mixed fluid environment. Human chondrocytes seeded into polyglycolic acid (PGA) mesh or PGA-alginate scaffolds were precultured in shaking T-flasks or recirculation perfusion bioreactors for 2.5 or 4 weeks prior to mechanical stimulation in the mechanobioreactor. Constructs were subjected to intermittent unconfined shear and compressive loading at a frequency of 0.05?Hz using a peak-to-peak compressive strain amplitude of 2.2% superimposed on a static axial compressive strain of 6.5%. The mechanical treatment was carried out for up to 2.5 weeks using a loading regime of 10?min duration each day with the direction of the shear forces reversed after 5?min and release of all loading at the end of the daily treatment period. Compared with shaking T-flasks and mechanobioreactor control cultures without loading, mechanical treatment improved the amount and quality of cartilage produced. On a per cell basis, synthesis of both major structural components of cartilage, glycosaminoglycan (GAG) and collagen type II, was enhanced substantially by up to 5.3- and 10-fold, respectively, depending on the scaffold type and seeding cell density. Levels of collagen type II as a percentage of total collagen were also increased after mechanical treatment by up to 3.4-fold in PGA constructs. Mechanical treatment had a less pronounced effect on the composition of constructs precultured in perfusion bioreactors compared with perfusion culture controls. This work demonstrates that the quality of tissue-engineered cartilage can be enhanced significantly by application of simultaneous dynamic mechanical shear and compression, with the greatest benefits evident for synthesis of collagen type II. PMID:22095592

Shahin, Kifah; Doran, Pauline M



Lossless compression algorithm for multispectral imagers  

NASA Astrophysics Data System (ADS)

Multispectral imaging is becoming an increasingly important tool for monitoring the earth and its environment from space borne and airborne platforms. Multispectral imaging data consists of visible and IR measurements from a scene across space and spectrum. Growing data rates resulting from faster scanning and finer spatial and spectral resolution makes compression an increasingly critical tool to reduce data volume for transmission and archiving. Research for NOAA NESDIS has been directed to finding for the characteristics of satellite atmospheric Earth science Imager sensor data what level of Lossless compression ratio can be obtained as well as appropriate types of mathematics and approaches that can lead to approaching this data's entropy level. Conventional lossless do not achieve the theoretical limits for lossless compression on imager data as estimated from the Shannon entropy. In a previous paper, the authors introduce a lossless compression algorithm developed for MODIS as a proxy for future NOAA-NESDIS satellite based Earth science multispectral imagers such as GOES-R. The algorithm is based on capturing spectral correlations using spectral prediction, and spatial correlations with a linear transform encoder. In decompression, the algorithm uses a statistically computed look up table to iteratively predict each channel from a channel decompressed in the previous iteration. In this paper we present a new approach which fundamentally differs from our prior work. In this new approach, instead of having a single predictor for each pair of bands we introduce a piecewise spatially varying predictor which significantly improves the compression results. Our new algorithm also now optimizes the sequence of channels we use for prediction. Our results are evaluated by comparison with a state of the art wavelet based image compression scheme, Jpeg2000. We present results on the 14 channel subset of the MODIS imager, which serves as a proxy for the GOES-R imager. We will also show results of the algorithm for on NOAA AVHRR data and data from SEVIRI. The algorithm is designed to be adapted to the wide range of multispectral imagers and should facilitate distribution of data throughout globally. This compression research is managed by Roger Heymann, PE of OSD NOAA NESDIS Engineering, in collaboration with the NOAA NESDIS STAR Research Office through Mitch Goldberg, Tim Schmit, Walter Wolf.

Gladkova, Irina; Grossberg, Michael; Gottipati, Srikanth



Bilateral hip arthroplasty: is 1-week staging the optimum strategy?  

PubMed Central

Seventy-nine patients underwent bilateral hip arthroplasty staged either at 1 week (Group 1) or after greater intervals (as suggested by the patients, mean 44 weeks, range 16-88 weeks) (Group 2), over a five year period at one Institution. Sixty-eight patients (29 bilateral hip resurfacings and 39 total hip replacements) completed questionnaires regarding their post-operative recovery, complications and overall satisfaction with the staging of their surgery. There was no significant age or ASA grade difference between the patient groups. Complication rates in the two groups were similar and overall satisfaction rates were 84% in Group 1 (n = 32) and 89% in Group 2 (n = 36). Cumulative hospital lengths of stay were significantly longer in Group 1 patients (11.9 days vs 9.1 days)(p < 0.01); this was true for both hip resurfacing and total hip arthroplasty patients, however resurfacing patients stays were significantly shorter in both groups (p < 0.01). Postoperative pain resolved earlier in Group 1 patients at a mean of 20.9 weeks compared with a cumulative 28.9 weeks (15.8 and 13.1 weeks) for Group 2 patients (p = 0.03). The mean time to return to part-time work was 16.4 weeks for Group 1, and a cumulative 17.2 weeks (8.8 and 8.4 weeks) for Group 2. The time to return to full-time work was significantly shorter for Group 1 patients (21.0 weeks, compared with a cumulative 29.7 weeks for Group 2)(p < 0.05). The time to return to both full and part-time work was significantly shorter in total hip replacement patients with 1-week staging compared with delayed staging (22.0 vs 35.8 weeks (p = 0.02), and 13.8 vs 19.3 weeks (p = 0.03) respectively). Hip resurfacing patients in Group 2 had significantly shorter durations of postoperative pain and were able to return to part-time and full time work sooner than total hip arthroplasty patients. There was a general trend towards a faster recovery and resumption of normal activities following the second operation in Group 2 patients, compared with the first operation. Bilateral hip arthroplasty staged at a 1-week interval resulted in an earlier resolution of hip pain, and an earlier return to full-time work (particularly following total hip replacement surgery), with high levels of patient satisfaction and no increased risk in complications; however the hospital length of stay was significantly longer. The decision for the timing of staged bilateral surgery should be made in conjunction with the patient, making adjustments to accommodate their occupational needs and functional demands.



Compression-shear study of glass reinforced polyester  

Microsoft Academic Search

Fiber reinforced organic matrix composites, due to their lower density, are being considered for armor applications where weight is an important factor. In this work, shock wave experiments were performed on Glass Reinforced Polyester (GRP) composite to investigate delamination due to normal and off-axis impact. This study extends the prior work of Dandekar and Beaulieu which examined both the compressive

J. Michael Boteler



Intermittent pneumatic compression devices.  


Intermittent pneumatic compression (IPC) devices are used to aid circulation in the lower limbs as a means of preventing deep vein thrombosis--a condition that can be dangerous and even fatal if it results in a pulmonary embolism. To be effective, IPC devices need to be safe, easy to use, and comfortable. Our Evaluation tells you which products meet these qualifications and how you can select one that best suits your needs. We tested and rated the following products: the VenaFlow, supplied by Aircast/DJO; the Flowtron Excel and Flowtron Universal, supplied by Huntleigh Healthcare; the PlexiPulse and Pulse SC, supplied by Kinetic Concepts Inc. (KCI); the A-V Impulse System, SCD Express, and SCD Response, supplied by Tyco Healthcare/Kendall. PMID:17696075



Work Environment, Job Satisfaction, Top Employees Work Interests  

Microsoft Academic Search

A survey of pig producers and employees was conducted to document rends in the industry. These surveys have been conducted four times: 1990, 1995, 2000, and 2005. Trends show that hours worked per week in 2005 declined from the 2000 levels. Employees indicated that they worked, on average, 45.3 hours per week in 2005 as compared to 48.7 hours in

James B. Kliebenstein; Terrance M. Hurley; Peter F. Orazem; Dale Miller; Steve May



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.…

Marx, Gary E.



Understanding Infidelity: An Interview with Gerald Weeks  

ERIC Educational Resources Information Center

|In this interview, Gerald Weeks shares his expertise on the topic of infidelity and couples counseling. Dr. Weeks defines infidelity, presents assessment strategies for treating the issue of infidelity, and discusses an intersystemic model for infidelity treatment when counseling couples. Dr. Weeks also provides insight into common mistakes made…

Smith, Travis



77 FR 42941 - Captive Nations Week, 2012  

Federal Register 2010, 2011, 2012, 2013

...Proclamation 8841--Captive Nations Week, 2012 Memorandum of July 11, 2012...8841 of July 16, 2012 Captive Nations Week, 2012 By the President of the United States...Eisenhower first proclaimed Captive Nations Week amidst an escalating Cold War, he...



78 FR 24323 - National Park Week, 2013  

Federal Register 2010, 2011, 2012, 2013

...Proclamation 8961 of April 19, 2013 National Park Week, 2013 By the President of the United be passed on. During National Park Week, we celebrate the wonders entrusted to...summon us to experience it firsthand. This week, the National Park Service will make...



77 FR 62133 - Fire Prevention Week, 2012  

Federal Register 2010, 2011, 2012, 2013

...8881 of October 5, 2012 Fire Prevention Week, 2012 By the President of the United States...heartbreaking. During Fire Prevention Week, we resolve to protect ourselves, our...immediately. As we mark Fire Prevention Week by recommitting to preparedness, we...



77 FR 69733 - National Family Week, 2012  

Federal Register 2010, 2011, 2012, 2013

...8906 of November 16, 2012 National Family Week, 2012 By the President of the United States...strength of character in their children. This week, we celebrate the unity and compassion...hard to get ahead. During National Family Week, let us recommit to keeping...



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



Occupational Exposure Limits For Novel Work Schedules  

Microsoft Academic Search

Work schedules other than 7 to 8?hr\\/day and 40?hr\\/week are being introduced in many industrial operations. Novel work schedules, such as four 10-hour workdays per week or three 12-hour workdays per week for three weeks followed by four 12-hour workdays for three weeks and several other plans are presently being used. The Threshold Limit Values (TLV) do not apply to




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



A new rabbit model for the study on cervical compressive myelopathy.  


Development process and pathology of myelopathy due to chronic spinal cord compression have not been fully elucidated. This study was conducted in order to establish an experimental model which can efficiently produce myelopathy and be useful in the studies on myelopathy due to chronic spinal cord compression. Under electrophysiological monitoring of the spinal cord, anterior compression was produced on C5 using a plastic screw. Two weeks later, a plastic plate was inserted under the C5 arch. For the subsequent 10 months on average, walking pattern and MR images were periodically monitored. Before the sacrifice, electrophysiological test was performed and then histopathological examination was done. Palsy appeared at 5 months on average after the addition of posterior compression. Mean compression ratio of the spinal cord calculated on MR images was 34%. All animals with compression showed a high intramedullary signal intensity, and the mean contrast-to-noise ratio (CNR) in the compressed area was 49%. Electrophysiological test showed a significant decrease in the amplitude of spinal cord evoked potentials (SCEPs) at the given compression level. Histology showed flattening of the anterior horn, disappearance and necrosis of anterior horn cells in the gray matter; and demyelination and axonal degeneration in the white matter. The antero-posterior compression produces the condition of spinal canal stenosis. Repeated antero-posterior compression to the spinal cord is important in establishing myelopathy. The present animal model was evaluated to be useful in the studies on myelopathy. PMID:11518269

Kanchiku, T; Taguchi, T; Kaneko, K; Yonemura, H; Kawai, S; Gondo, T



Stability of Compressible Boundary Layers.  

National Technical Information Service (NTIS)

The stability of compressible 2-D and 3-D boundary layers is reviewed. The stability of 2-D compressible flows differs from that of incompressible flows in two important features: There is more than one mode of instability contributing to the growth of di...

A. H. Nayfeh



Application specific compression : final report.  

SciTech Connect

With the continuing development of more capable data gathering sensors, comes an increased demand on the bandwidth for transmitting larger quantities of data. To help counteract that trend, a study was undertaken to determine appropriate lossy data compression strategies for minimizing their impact on target detection and characterization. The survey of current compression techniques led us to the conclusion that wavelet compression was well suited for this purpose. Wavelet analysis essentially applies a low-pass and high-pass filter to the data, converting the data into the related coefficients that maintain spatial information as well as frequency information. Wavelet compression is achieved by zeroing the coefficients that pertain to the noise in the signal, i.e. the high frequency, low amplitude portion. This approach is well suited for our goal because it reduces the noise in the signal with only minimal impact on the larger, lower frequency target signatures. The resulting coefficients can then be encoded using lossless techniques with higher compression levels because of the lower entropy and significant number of zeros. No significant signal degradation or difficulties in target characterization or detection were observed or measured when wavelet compression was applied to simulated and real data, even when over 80% of the coefficients were zeroed. While the exact level of compression will be data set dependent, for the data sets we studied, compression factors over 10 were found to be satisfactory where conventional lossless techniques achieved levels of less than 3.

Melgaard, David Kennett; Byrne, Raymond Harry; Myers, Daniel S.; Harrison, Carol D.; Lee, David S.; Lewis, Phillip J.; Carlson, Jeffrey J.



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



Compression Coding for HDTV Signal.  

National Technical Information Service (NTIS)

The paper describes a signal compression coding for High Definition Television (HDTV). The compression coding is a key technology for processing bulky information of the HDTV. From the simulation results, it is verified that the coding rates of 30 Mbps th...

M. Ohta S. Nogaki



Energy savings with compressed air  

Microsoft Academic Search

The production of compressed air can be one of the most expensive processes in manufacturing facilities. Annual operating costs of air compressors, dryers and supporting equipment can account for up to 70% of the total electric bill. Because the greatest single cost of manufacturing may be attributed to compressed-air, it follows that the greatest potential for energy conservation may also




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



Triaxial compression of aluminium foams  

Microsoft Academic Search

Triaxial compressive tests have been conducted on CYMAT closed-cell aluminium foams of five different relative densities to investigate their initial failure surfaces under multiaxial loading. Quasi-static uniaxial compressive and tensile tests have also been performed to obtain their uniaxial strength. The experimentally measured yield surfaces are compared with various published phenomenological yield surface models. Reasonable agreement has been observed when

D. Ruan; G. Lu; L. S. Ong; B. Wang



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



30 CFR 75.1730 - Compressed air; general; compressed air systems.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 2010-07-01 false Compressed air; general; compressed air systems. 75.1730 Section 75.1730 ...STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1730 Compressed air; general; compressed air...



30 CFR 75.1730 - Compressed air; general; compressed air systems.  

Code of Federal Regulations, 2010 CFR

... 2009-07-01 2009-07-01 false Compressed air; general; compressed air systems. 75.1730 Section 75.1730 ...STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1730 Compressed air; general; compressed air...



76 FR 4338 - Research and Development Strategies for Compressed & Cryo-Compressed Hydrogen Storage Workshops  

Federal Register 2010, 2011, 2012, 2013

...Compressed & Cryo- Compressed Hydrogen Storage Workshops AGENCY: Fuel Cell Technologies...Laboratory, in conjunction with the Hydrogen Storage team of the EERE Fuel Cell Technologies...compressed and cryo-compressed hydrogen storage in the Washington, DC metro area....



Treatment of recurrent radial artery pseudoaneurysms by prolonged mechanical compression.  


As radial artery pseudoaneurysm (PA) is a rare complication of transradial catheterization, data on their management are sparse. Here, we report the case of a 77-year-old woman who underwent right transradial diagnostic cardiac catheterization, and subsequently developed a symptomatic PA. She underwent initial treatment with 20 minutes of mechanical compression with a Hemoband (Hemoband Corporation) with initial success. Three weeks later, she developed recurrence of her PA, and was treated with 24 hours of mechanical compression, wearing the Hemoband as an outpatient, with sustained resolution of the PA confirmed by ultrasound 1 month later, and no neurologic or further vascular complications. In addition to demonstrating that an initial PA as well as its recurrence can be treated with prolonged mechanical compression, we review the literature regarding radial artery PAs and their treatment. PMID:23813066

Nazer, Babak; Boyle, Andrew



Internship Training Work Group.  

National Technical Information Service (NTIS)

The following report was written by the group leader several weeks following the conference and distributed to all work group members and the Psychology Consultant. There were two main concerns of the work group: how to improve and achieve a better fit be...

F. H. Rath



Rate dependent biomechanical properties of corneal stroma in unconfined compression.  


The corneal stroma is a highly ordered extracellular matrix and mainly responsible for the mechanical strength of the cornea. The rate dependent mechanical and rheological properties of the cornea are not completely understood and there is large variation in the reported estimates. In this work, the rate dependent mechanical behavior of the corneal stroma was investigated using experimental studies and theoretical models. Unconfined compression stress-relaxation experiments at different displacement rates and compressive strains were conducted. The unconfined compression material parameters, i.e. corneal out-of-plane modulus, in-plane modulus and permeability coefficient were determined from curve-fitting the experimental data with a transversely isotropic biphasic model. It was found that the maximum force reached during the step loading increased with both increasing magnitude and rate of the compressive strain. It was also observed that at all loading rates the in-plane Young's modulus increased with increasing strain, while the permeability coefficient decayed with increasing compressive strain. At a constant compressive strain, both the in-plane Young's modulus and the permeability coefficient increased with increasing the loading rate. Regardless of loading rates and compressive strains, a range of corneal out-of-plane modulus of 0.6 kPa to 13.8 kPa, in-plane modulus of 0.5 MPa to 4.8 MPa, and permeability coefficient of 1×10?¹? m?/N·s to 7×10?¹? m?/N·s was found. PMID:23863279

Hatami-Marbini, Hamed; Etebu, Ebitimi



Rate-distortion-based segmentation for MRC compression  

NASA Astrophysics Data System (ADS)

Effective document compression algorithms require scanned document images be first segmented into regions such as text, pictures and background. In this paper, we present a document compression algorithm that is based on the 3-layer (foreground/mask/background)MRC (mixture raster content) model. This compression algorithm first segments a scanned document image into different classes. Then, each class is transformed to the 3-layer MRC model differently according to the property of that class. Finally, the foreground and the back-ground layers are compressed using JPEG with customized quantization tables. The mask layer is compressed using JBIG2. The segmentation is optimized in the sense of rate distortion for the 3-layer MRC representation. It works in a closed loop fashion by a lying each transformation to each region of the document and then selecting the method that yields the best rate-distortion trade-off. The proposed segmentation algorithm can not only achieve a better rate-distortion trade-off, but also produce more robust segmentations by eliminating those mis-classifications which can cause severe artifacts. At similar bit rates, our MRC compression with the rate- distortion based segmentation can achieve a much higher subjective quality than state-of-the-art compression algorithms, such as JPEG and JPEG-2000.

Cheng, Hui; Feng, Guotong; Bouman, Charles A.



Evaluation study of compressed sensing for neural spike recordings.  


In this paper, an evaluation study of compressed sensing (CS) for neural action potential (spike) signals in MATLAB is presented. State-of-the-art neural recorders use 100 or more parallel channels to measure neural activity resulting in a data rate of 16 - 20 Mbit/s. Since a low-power design is required for an implanted neural recorder, it seems advantageous to compress the neural data prior to the wireless transmission. The continuous neural spike signals are compressed and transmitted to facilitate the possibility of an unrestricted data analysis at the receiver. Synthesized and recorded neural data sets are used to test the performance of CS. The 6-level Daubechies-8 wavelet decomposition matrix and two learned dictionary matrices are utilized as dictionaries for CS. The compression results are evaluated with the spike sorting program OSort. CS is shown to work for the compression of low-noise synthesized neural spike signals with a compression rate of 2.05, but cannot be recommended for the compression of neural spike signals in general. PMID:23366683

Bulach, Christoph; Bihr, Ulrich; Ortmanns, Maurits



ABC's “Person of the Week”: American Values in Television News  

Microsoft Academic Search

This study analyzed five years of “ABC World News Tonight's ‘Person of the Week’” segments to identify prominent types of people and values endorsed by mainstream news media. Individuals most frequently selected for ABC's honor lived in the United States; worked in politics and entertainment; and were white, male, and famous. American values such as individualism, heroism, and unselfishness were

Stephanie Greco Larson; Martha Bailey



Radiator debris removing apparatus and work machine using same  


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); Elliott, Dwight E. (Chillicothe, IL)



29 CFR 1917.154 - Compressed air.  

Code of Federal Regulations, 2013 CFR

...with the provisions of subpart E of this part during cleaning with compressed air. Compressed air used for cleaning shall not exceed a pressure of 30 psi. Compressed air shall not be used to clean...



Spinal cord compression of primary extragonadal giant yolk sac tumor  

Microsoft Academic Search

Study design:Case report.Objective:To report an adult male patient with a primary extragonadal giant yolk sac tumor presenting with acute spinal cord compression.Setting:Faculty of Medicine, University of Dicle, Diyarbakir, Turkey.Method:A 31-year-old man was referred to our department with a diagnosis of Pott's disease, a complaint of back pain and gait difficulty for 2 weeks. Neurological examination showed spastic paraparesis and hypoesthesia

A Guzel; M Tatli; D Belen; H Seckin



An efficient and extensible approach for compressing phylogenetic trees  

PubMed Central

Background Biologists require new algorithms to efficiently compress and store their large collections of phylogenetic trees. Our previous work showed that TreeZip is a promising approach for compressing phylogenetic trees. In this paper, we extend our TreeZip algorithm by handling trees with weighted branches. Furthermore, by using the compressed TreeZip file as input, we have designed an extensible decompressor that can extract subcollections of trees, compute majority and strict consensus trees, and merge tree collections using set operations such as union, intersection, and set difference. Results On unweighted phylogenetic trees, TreeZip is able to compress Newick files in excess of 98%. On weighted phylogenetic trees, TreeZip is able to compress a Newick file by at least 73%. TreeZip can be combined with 7zip with little overhead, allowing space savings in excess of 99% (unweighted) and 92%(weighted). Unlike TreeZip, 7zip is not immune to branch rotations, and performs worse as the level of variability in the Newick string representation increases. Finally, since the TreeZip compressed text (TRZ) file contains all the semantic information in a collection of trees, we can easily filter and decompress a subset of trees of interest (such as the set of unique trees), or build the resulting consensus tree in a matter of seconds. We also show the ease of which set operations can be performed on TRZ files, at speeds quicker than those performed on Newick or 7zip compressed Newick files, and without loss of space savings. Conclusions TreeZip is an efficient approach for compressing large collections of phylogenetic trees. The semantic and compact nature of the TRZ file allow it to be operated upon directly and quickly, without a need to decompress the original Newick file. We believe that TreeZip will be vital for compressing and archiving trees in the biological community.



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.



Lossless compression of pseudocolor images  

NASA Astrophysics Data System (ADS)

In a pseudo-color (color-mapped) image pixel values represent indices that point to color values in a look-up table. Well-known linear predictive schemes, such as JPEG and CALIC, perform poorly when used with pseudo-color images, while universal compressors, such as Gzip, Pkzip and Compress, yield better compression gain. Recently, Burrows and Wheeler introduced the Block Sorting Lossless Data Compression Algorithm (BWA). The BWA algorithm received considerable attention. It achieves compression rates as good as context-based methods, such as PPM, but at execution speeds closer to Ziv-Lempel techniques. The BWA algorithm is mainly composed of a block-sorting transformation which is known as Burrows-Wheeler Transformation (BWT), followed by Move-To-Front coding. In this paper, we introduce a new block transformation, Linear Order Transformation (LOT). We delineate its relationship to BWT and show that LOT is faster than BWT transformation. We then show that when MTF coder is employed after the LOT, the compression gain obtained is better than the well-known compression techniques, such as GIF, JPEG, CALLIC, Gzip, LZW (Unix Compress) and the BWA for pseudo-color images.

Arnavut, Ziya; Leavitt, David; Abdulazizoglu, Meral



77 FR 31143 - Emergency Medical Services Week, 2012  

Federal Register 2010, 2011, 2012, 2013

...Proclamation 8824--Emergency Medical Services Week, 2012 Proclamation 8825--National Safe Boating Week, 2012 Proclamation 8826--National Small Business Week, 2012 Proclamation 8827--World Trade Week, 2012...



The Role of Transforms in Image Compression  

NASA Astrophysics Data System (ADS)

In today's multimedia wireless communication, major issue is bandwidth needed to satisfy real time transmission of image data. Compression is one of the good solutions to address this issue. Transform based compression algorithms are widely used in the field of compression, because of their de-correlation and other properties, useful in compression. In this paper, comparative study of compression methods is done based on their types. This paper addresses the issue of importance of transform in image compression and selecting particular transform for image compression. A comparative study of performance of a variety of different image transforms is done base on compression ratio, entropy and time factor.

Bairagi, V. K.; Sapkal, A. M.; Gaikwad, M. S.



Sympathetically cooled and compressed positron plasma  

SciTech Connect

We report sympathetic cooling and compression of a few thousand positrons by laser-cooled {sup 9}Be{sup +} ions in a Penning ion trap. The observed centrifugal separation of the two species implies approximate rigid rotation of the positrons and {sup 9}Be{sup +} ions, and a positron density comparable to the {sup 9}Be{sup +} ion density of (greater-or-similar sign)4x10{sup 9} cm{sup -3}. We use the sharpness of the separation to place a 5-K upper limit on the positron temperature of motion parallel to the magnetic field. The positron lifetime is greater than two weeks in our room-temperature Penning trap.

Jelenkovic, B.M. [Time and Frequency Division, National Institute of Standards and Technology, Boulder, Colorado 80303 (United States); Institute of Physics, University of Belgrade, Belgrade (Yugoslavia); Newbury, A.S.; Bollinger, J.J.; Itano, W.M. [Time and Frequency Division, National Institute of Standards and Technology, Boulder, Colorado 80303 (United States); Mitchell, T.B. [Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716 (United States)



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



Multi-shot compressed coded aperture imaging  

NASA Astrophysics Data System (ADS)

The classical methods of compressed coded aperture (CCA) still require an optical sensor with high resolution, although the sampling rate has broken the Nyquist sampling rate already. A novel architecture of multi-shot compressed coded aperture imaging (MCCAI) using a low resolution optical sensor is proposed, which is mainly based on the 4-f imaging system, combining with two spatial light modulators (SLM) to achieve the compressive imaging goal. The first SLM employed for random convolution is placed at the frequency spectrum plane of the 4-f imaging system, while the second SLM worked as a selecting filter is positioned in front of the optical sensor. By altering the random coded pattern of the second SLM and sampling, a couple of observations can be obtained by a low resolution optical sensor easily, and these observations will be combined mathematically and used to reconstruct the high resolution image. That is to say, MCCAI aims at realizing the super resolution imaging with multiple random samplings by using a low resolution optical sensor. To improve the computational imaging performance, total variation (TV) regularization is introduced into the super resolution reconstruction model to get rid of the artifacts, and alternating direction method of multipliers (ADM) is utilized to solve the optimal result efficiently. The results show that the MCCAI architecture is suitable for super resolution computational imaging using a much lower resolution optical sensor than traditional CCA imaging methods by capturing multiple frame images.

Shao, Xiaopeng; Du, Juan; Wu, Tengfei; Jin, Zhenhua



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



Compressive strength of fiber reinforced highly compressible clay  

Microsoft Academic Search

Admixtures and geogrids are frequently used in practice to stabilize soils and to improve their load carrying capacity. In this study, polyester fibers were mixed with soft clay soil to investigate the relative strength gain in terms of unconfined compression. Samples were tested in unconfined compression with 0%, 0.5%, 1.0%, 1.5% and 2.0% plain and crimped polyester fibers. Verifications tests

Arvind Kumar; Baljit Singh Walia; Jatinder Mohan



Balancing Work and Family through Flexible Work Options. Monograph. Volume 9, Number 1.  

ERIC Educational Resources Information Center

|More than 58 percent of all women working in the U.S. labor force, many of them sole supports of their families, and 67 percent of women with children under age 18 are working. Therefore, more flexible work options are being made to allow a balance of work and family. Increasingly available options include work at home, compressed workweeks,…

Sachs, Sharon


[Compressive ischemic neuropathies of the upper extremities and work].  


The objective of the presented study was to motile that cumulative trauma disorders of the upper extremities in recent years leads to arising morbidity and applications for compensation for occupational diseases. This rise is probably not associated with an increase of this disorder but a different awareness of workers and doctors as regards the possible adverse effect of forceful and frequently repeated movements of the upper extremities on their function, extended diagnostics and notification. It is important to master the diagnosis of these diseases and interpretation of auxiliary examinations to prevent inadequate payment of damages to the affected subjects and on the other hand to prevent breakdown or in adequate function of the financial provisions in this area. A number of syndromes of the mentioned conditions has very few objective symptoms and abnormal results of auxiliary examinations. The diagnosis of stenotic syndromes has a compared with other disorders great support in electrophysiological techniques, their high sensitivity and specificity (1, 15). The authors discuss therefore their problems and suggest electrophysiological criteria of medium grade affections in the carpal tunnel syndrome which is the condition for compensation for occupational disease and which so far was defined only roughly in this country. PMID:10510541

Kadanka, Z; Brhel, P



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.



Progressive ROI coding and diagnostic quality for medical image compression  

NASA Astrophysics Data System (ADS)

This work addresses the delicate problem of lossy compression of medical images. More specifically, a selective allocation of coding resources is introduced based on the concept of 'diagnostic interest' and an interactive methodology based on a new measure of 'diagnostic quality'. The selective allocation of resources is made possible by a selection a priori of regions of specific interest for diagnostic purpose. The idea is to change the precision of representation in a transformed domain of region of particular interest, through a weighting procedure by an on- line user-defined quantization matrix. The overall compression method is multi-resolution, provides for an embedded generation of the bit-stream and guarantees for a good rate-distortion trade-off, at various bit-rates, with spatially varying reconstruction quality. This work also analyzes the delicate issue of a professional usage of lossy compression in a PACS environment. The proposed compression methodology gives interesting insights in favor of using lossy compression in a controlled fashion by the expert radiologist. Most of the ideas presented in this work have been confirmed by extensive experimental simulations involving medical expertise.

Signoroni, Alberto; Leonardi, Riccardo



The failure of brittle materials under overall compression: Effects of loading rate and defect distribution  

Microsoft Academic Search

The constitutive behaviors and failure processes of brittle materials under far-field compressive loading are studied in this work. Several approaches are used: experiments to study the compressive failure behavior of ceramics, design of experimental techniques by means of finite element simulations, and the development of micro-mechanical damage models to analyze and predict mechanical response of brittle materials under far-field compression.

Bhasker Paliwal



Survey of compressed-domain features used in audio-visual indexing and analysis  

Microsoft Academic Search

In this paper, we attempt to provide a comprehensive and high-level review of audio- visual features that can be extracted from the standard compressed domains, such as MPEG-1 and MPEG-2. The paper is motivated by the myriad of active research works in extraction and application of compressed-domain features in various fields, such as index- ing, filtering, and manipulation. Compressed-domain approaches

Hualu Wang; Ajay Divakaran; Anthony Vetro; Shih-fu Chang; Huifang Sun



Compression in encapsulated carboxylic acid homodimers  

NASA Astrophysics Data System (ADS)

A density functional theory study has been carried out on five carboxylic acid homodimers, free and encapsulated, in order to study the effect of encapsulation or compression. Attractive interactions between the guests and the walls of the capsules stabilize encapsulation even in cases of severe confinement where formation of dimers is unfavorable. Larger hydrogen bonds are calculated for the encapsulated than the isolated dimers except for the case of the bulkiest dimer considered, where encapsulation leads to shortening of the hydrogen bond. Shorter hydrogen-bond lengths with increasing size of the encapsulated dimers are calculated, in agreement with experimental work.

Tzeli, Demeter; Petsalakis, Ioannis D.; Theodorakopoulos, Giannoula



Diagnoses of coaxial probes in shock compression.  


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



Compressed sensing for phase contrast CT  

NASA Astrophysics Data System (ADS)

Modern x-ray techniques opened the possibility to retrieve phase information. Phase-contrast computed tomography (PCCT) has the potential to significantly improve soft tissue contrast. Radiation dose, however, continues to be an issue when moving from bench to bedside. Dose reduction in this work is achieved by sparsely acquiring PCCT data. To compensate for appearing aliasing artifacts we introduce a compressed sensing (CS) reconstruction framework. We present the feasibility of CS on PCCT with numerical as well as measured phantom data. The results proof that CS compensates for under-sampling artifacts and maintains the superior soft tissue contrast and detail visibility in the reconstructed images.

Gaass, Thomas; Potdevin, Guillaume; Noël, Peter B.; Tapfer, Arne; Willner, Marian; Herzen, Julia; Bech, Martin; Pfeiffer, Franz; Haase, Axel



[The ulnar nerve compression syndrome].  


The ulnar nerve has to bear a large amount of compression, especially in the cubital tunnel, which can be deducted from the topographic relation of this nerve to the elbow. Apart from tightness of the tunnel, intraarticular changes can also cause compression of the nerve. A further narrow tunnel in the course of the ulnar nerve is the "loge de GUYON", situated in the hypothenar region. A careful neurological examination of sensory and motor signs as well as an accurate electromyographical examination differentiate compression syndromes from other neuropathies. Two unusual cases of a functional cubital tunnel syndrome are demonstrated: their cause was primarily a chondromatosis of the elbow joint in one case a functional vasal compression in the other case. PMID:7250791

Thümler, P; Goymann, V



Satellite image compression using wavelet  

NASA Astrophysics Data System (ADS)

Image data is a combination of information and redundancies, the information is part of the data be protected because it contains the meaning and designation data. Meanwhile, the redundancies are part of data that can be reduced, compressed, or eliminated. Problems that arise are related to the nature of image data that spends a lot of memory. In this paper will compare 31 wavelet function by looking at its impact on PSNR, compression ratio, and bits per pixel (bpp) and the influence of decomposition level of PSNR and compression ratio. Based on testing performed, Haar wavelet has the advantage that is obtained PSNR is relatively higher compared with other wavelets. Compression ratio is relatively better than other types of wavelets. Bits per pixel is relatively better than other types of wavelet.

Santoso, Alb. Joko; Soesianto, F.; Dwiandiyanto, B. Yudi



Compressive Behavior of Fiber Composites.  

National Technical Information Service (NTIS)

The mechanical behavior of model composite specimens consisting of unidirectional piano-wire fibers in a matrix of Emerson and Cuming STYCAST 1264 was studied with compressive loading applied parallel to the fiber axis. Tests were conducted at temperature...

O. Orringer



Compressed gas fuel storage system  


A compressed gas vehicle fuel storage system comprised of a plurality of compressed gas pressure cells supported by shock-absorbing foam positioned within a shape-conforming container. The container is dimensioned relative to the compressed gas pressure cells whereby a radial air gap surrounds each compressed gas pressure cell. The radial air gap allows pressure-induced expansion of the pressure cells without resulting in the application of pressure to adjacent pressure cells or physical pressure to the container. The pressure cells are interconnected by a gas control assembly including a thermally activated pressure relief device, a manual safety shut-off valve, and means for connecting the fuel storage system to a vehicle power source and a refueling adapter. The gas control assembly is enclosed by a protective cover attached to the container. The system is attached to the vehicle with straps to enable the chassis to deform as intended in a high-speed collision.

Wozniak, John J. (Columbia, MD); Tiller, Dale B. (Lincoln, NE); Wienhold, Paul D. (Baltimore, MD); Hildebrand, Richard J. (Edgemere, MD)



Electrical conductivity of compressed argon  

SciTech Connect

The authors report calculations of the electrical conductivity of solid argon as a function of compression within the density functional local density approximation formulation for a norm-conserving pseudopotential using both electron-phonon coupling and molecular dynamics techniques.

Bauer, R. [Univ. Regensburg (Germany); Windl, W.; Collins, L.; Kress, J.; Kwon, I. [Los Alamos National Lab., NM (United States)



Preprototype Vapor Compression Distillation Subsystem.  

National Technical Information Service (NTIS)

A three-person capacity preprototype vapor compression distillation subsystem for recovering potable water from wastewater aboard spacecraft was designed, assembled, and tested. The major components of the subsystem are: (1) a distillation unit which incl...

G. S. Ellis R. A. Wynveen F. H. Schubert



Reversible compression of MR images.  


Methods for reversible coding can be classified according to the organization of the source model as either static, semi-adaptive, or adaptive. Magnetic resonance (MR) images have different statistical characteristics in the foreground and the background and separation is thus a promising path for reversible MR image compression. A new reversible compression method, based on static source models for foreground and background separately, is presented. The method is nonuniversal and uses contextual information to exploit the fact that entropy and bit rate are reduced by increasing the statistical order of the model. This paper establishes a realistic level of expectation regarding the bit rate in reversible MR image compression, in general, and the bit rate using static modeling, in particular. The experimental results show that compression using the new method can give bit rates comparable to the best existing reversible methods. PMID:10571384

Midtvik, M; Hovig, I



Behavior of mass concrete under biaxial compression-tension and triaxial compression-compression-tension  

Microsoft Academic Search

To meet the requirement of nonlinear analysis and design for mass concrete structures, the mechanical characteristics of mass\\u000a concrete specimens 25 × 25 × 40 cm with three-graded aggregate 5–80 mm under biaxial compression-tension and triaxial compression-compression-tension\\u000a was studied experimentally with the multiaxial concrete apparatus. In comparison with the corresponding wet-screened concrete\\u000a specimens 15 × 15 × 30 cm with two-graded aggregate 5–40 mm, it was found that the wet-screened effect and

H. L. Wang; Y. P. Song



Implementing a Dynamic Compressed Trie  

Microsoft Academic Search

We present an order-preserving general purpose data structure for binary data, the LPC-trie.The structure is a highly compressed trie, using both level and path compression. The memoryusage is similar to that of a balanced binary search tree, but the expected average depth issmaller. The LPC-trie is well suited to modern language environments with efficient memoryallocation and garbage collection. We present

Stefan Nilsson; Matti Tikkanen



Mayor Barrett to Demonstrate Emerald Ash Borer Treatment Demonstration Occurs During National Public Works Week & Emerald Ash Borer Week  

Microsoft Academic Search

th at 11:00 a.m. Location to be determine. Milwaukee is moving forward with plans to chemically treat all City-owned ash in an effort to moderate\\/mitigate the impact of EAB. In previous summers, time studies were conducted to compare efficiencies between a number of chemical delivery systems. They determined that pairing a hydraulic injection system from Arbor-Jet with the chemical Tree-age

Mayor Tom Barrett



National Poison Prevention Week Promotional Materials.  

ERIC Educational Resources Information Center

|This collection of materials for parents, early childhood workers, the elderly, and anyone in situations requiring safeguards against poisoning, spans the years 1993 and 1994 and is intended to promote National Poison Prevention Week. The materials included are: (1) the 31-page, illustrated report on National Poison Prevention Week for 1993,…

Poison Prevention Week Council, Washington, DC.


Using the Weekly Newspaper in Education.  

ERIC Educational Resources Information Center

|Intended for teachers in all subject areas at the elementary and secondary school levels, this booklet contains a variety of activities involving the use of the weekly newspaper as a teaching aid. Following a list of features of a weekly newspaper that make it suitable for classroom instruction, the activities are presented for elementary and…

Becker, Sharon; Kendall, Stuart


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.



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



Banned Books Week: Just the Beginning  

ERIC Educational Resources Information Center

|Founded in 1982, Banned Books Week is celebrated annually during the last week in September and will be observed from September 26-October 3 in 2009. The event acknowledges Americans' right to read the books of their choice regardless of whether the ideas, language, or images are controversial. This annual observance of banned books is a good…

Adams, Helen R.



Multiagent system for optimizing filter coefficients in image compression  

NASA Astrophysics Data System (ADS)

In this paper, we present a new intelligent agent-based method to design filter banks that maximize compression quality. In this method, a multi-agent system containing cooperating intelligent agents with different roles is developed to search for filter banks that improve image compression quality. The multi-agent system consists of one generalization agent, and several problem formulation, optimization, and compression agents. The generalization agent performs problem decomposition and result collection. It distributes optimization tasks to optimization agents, and later collects results and selects one solution that works well on all training images as the final output. Problem formulation agents build optimization models that are used by the optimization agents. The optimization formulation includes both the overall performance of image compression and metrics of individual filters. The compression performance is provided by the image coding agent. Optimization agents apply various optimization methods to find the best filter bank for individual training images. Our method is modular and flexible, and is suitable for distributed processing. In experiments, we applied the proposed method to a set of benchmark images and designed filter banks that improve the compression performance of existing filter banks.

Shang, Yi; Li, Longzhuang



Document compression using rate-distortion optimized segmentation  

NASA Astrophysics Data System (ADS)

Effective document compression algorithms require that scanned document images be first segmented into regions such as text, pictures, and background. In this paper, we present a multilayer compression algorithm for document images. This compression algorithm first segments a scanned document image into different classes, then compresses each class using an algorithm specifically designed for that class. Two algorithms are investigated for segmenting document images: a direct image segmentation algorithm called the trainable sequential MAP (TSMAP) segmentation algorithm, and a rate- distortion optimized segmentation (RDOS) algorithm. The RDOS algorithm works in a closed loop fashion by applying each coding method to each region of the document and then selecting the method that yields the best rate-distortion trade-off. Compared with the TSMAP algorithm, the RDOS algorithm can often result in a better rate-distortion trade-off, and produce more robust segmentations by eliminating those misclassifications which can cause severe artifacts. At similar bit rates, the multilayer compression algorithm using RDOS can achieve a much higher subjective quality then state-of-the-art compression algorithms.

Cheng, Hui; Bouman, Charles A.



SCADA Protocol Anomaly Detection Utilizing Compression (SPADUC) 2013  

SciTech Connect

There is a significant need to protect the nation’s energy infrastructures from malicious actors using cyber methods. Supervisory, Control, and Data Acquisition (SCADA) systems may be vulnerable due to the insufficient security implemented during the design and deployment of these control systems. This is particularly true in older legacy SCADA systems that are still commonly in use. The purpose of INL’s research on the SCADA Protocol Anomaly Detection Utilizing Compression (SPADUC) project was to determine if and how data compression techniques could be used to identify and protect SCADA systems from cyber attacks. Initially, the concept was centered on how to train a compression algorithm to recognize normal control system traffic versus hostile network traffic. Because large portions of the TCP/IP message traffic (called packets) are repetitive, the concept of using compression techniques to differentiate “non-normal” traffic was proposed. In this manner, malicious SCADA traffic could be identified at the packet level prior to completing its payload. Previous research has shown that SCADA network traffic has traits desirable for compression analysis. This work investigated three different approaches to identify malicious SCADA network traffic using compression techniques. The preliminary analyses and results presented herein are clearly able to differentiate normal from malicious network traffic at the packet level at a very high confidence level for the conditions tested. Additionally, the master dictionary approach used in this research appears to initially provide a meaningful way to categorize and compare packets within a communication channel.

Gordon Rueff; Lyle Roybal; Denis Vollmer



Modeling Drift-Compression for Heavy-Ion Fusion  

NASA Astrophysics Data System (ADS)

Beams for heavy-ion fusion (HIF) must be compressed lengthwise by a factor of more than ten between an induction accelerator and the final-focus magnets. The compression scenario favored by the US HIF program is to impose a head-to-tail velocity increase or "tilt", so the beam tail approaches the head in a "drift-compression" section. The beam current and velocity must be accurately tailored before drift-compression so that the longitudinal space-charge field removes the velocity tilt just as the beam traverses the final-focus lattice. The principle physics questions posed by this section are how much the total emittance grows, whether a beam halo develops, and how these processes scale with beam and lattice parameters. A second broad area of research is optimizing the initial pulse-shaping schedule to minimize the bandwidth and volt-seconds requirements of the pulsed power. This paper presents recent theoretical work to model the final longitudinal compression of HIF beams. Pulse-shaping fields are calculated using a fluid/envelope dynamics model and then used in the three-dimensional electrostatic particle-in-cell (PIC) code WARP3d to study beam transport during pulse-shaping and drift-compression. Possible low-energy, near-term experiments are discussed, and for these, we examine how emittance growth and sensitivity to errors scale with the beam and lattice parameters.

Sharp, W. M.; Barnard, J. J.; Friedman, A.; Grote, D. P.; Celata, C. M.; Yu, S. S.



Evaluating Pregnant Occupant Restraints: The Effect of Local Uterine Compression on the Risk of Fetal Injury  

PubMed Central

In order to develop effective restraint systems for the pregnant occupant, injury criteria for determining fetal injury risk must be developed. This study presents computer simulations of a 30 week pregnant occupant that illustrate the importance of local uterine compression on the risk of fetal injury. Frontal impact simulations with a range of velocities and belt positions were used to identify the best correlation between local uterine compression and peak strain measured at the uterine-placental interface. It is suggested that future pregnant dummy development and specifically pregnant injury criteria should be based on local uterine compression relative to the placental attachment location.

Duma, Stefan M.; Moorcroft, David M.; Stitzel, Joel D.; Duma, Greg G.



Symbol Ranking Text Compression  

Microsoft Academic Search

In his work on the information content of English text in 1951, Shannon described a method of recoding the input text, a technique which has apparently lain dormant for the ensuing 45 years. Whereas traditional compressors exploit symbol frequencies and symbol contexts, Shannon's method adds the concept of \\

Peter Fenwick



Finding Structure via Compression  

Microsoft Academic Search

A statistical language model may be used to segment a data sequence by thresholding its instantaneous entropy. In this paper we de- scribe how this process works, and we apply it to the problem of discovering separator sym- bols in a text. Our results show that language models which bootstrap themselves with struc- ture found in this way undergo a

Jason L. Hutchens; Michael D. Alder



Method and apparatus for compressing gases  

Microsoft Academic Search

A gas compressor has at least one closed container with gas inlet means for filling the container with a gas to be compressed and gas outlet means through which compressed gas can leave the container. When the container has been filled with gas to be compressed, a fluid is forced into the container to compress the gas therein and force

P. M. Perrine; C. A. Perrine



ECG compression using discrete symmetric wavelet transform  

Microsoft Academic Search

This paper proposes a new ECG signal compression algorithm using a discrete symmetric wavelet transform. This proposed compression scheme may find applications in digital Holter recording, in ECG signal archiving and in ECG data transmission through communication channels. Using the new method, a compression ratio of 8 to 1 can be achieved with PRD=3.9%, in contrast to the AZTEC compression

A. Djohan; T. Q. Nguyen; W. J. Tompkins



Axial compression fracture in carbon fibres  

Microsoft Academic Search

Axial compression fracture of carbon fibres was studied by embedding single fibres in epoxy resin and compressing the specimens parallel to the fibre axis. By careful optical monitoring of the fibre surface the earliest stages of fracture were identified leading to estimates of the fibre axial compression failure strengths. Compression strength decreases markedly from about 2.2 GN m-2 for moderately

H. M. Hawthorne; E. Teghtsoonian



File System Support for Delta Compression  

Microsoft Academic Search

Delta compression, which consists of compactly encoding one file version as the result of changes to an- other, can improve efficiency in the use of network and disk resources. Delta compression techniques are readily available and can result in compression factors of five to ten on typical data, however managing delta-compressed storage is difficult. I present a system that attempts

Joshua P. MacDonald



Audio representations for data compression and compressed domain processing  

NASA Astrophysics Data System (ADS)

In the world of digital audio processing, one usually has the choice of performing modifications on the raw audio signal or performing data compression on the audio signal. But, performing modifications on a data compressed audio signal has proved difficult in the past. This thesis provides new representations of audio signals that allow for both very low bit rate audio data compression and high quality compressed domain processing and modifications. In this system, two compressed domain processing algorithms are available: time-scale and pitch-scale modifications. Time-scale modifications alter the playback speed of audio without changing the pitch. Similarly, pitch-scale modifications alter the pitch of the audio without changing the playback speed. The algorithms presented in this thesis segment the input audio signal into separate sinusoidal, transients, and noise signals. During attack-transient regions of the audio signal, the audio is modeled by transform coding techniques. During the remaining non-transient regions, the audio is modeled by a mixture of multiresolution sinusoidal modeling and noise modeling. Careful phase matching techniques at the time boundaries between the sines and transients allow for seamless transitions between the two representations. By separating the audio into three individual representations, each can be efficiently and perceptually quantized. In addition, by segmenting the audio into transient and non-transient regions, high quality time-scale modifications that stretch only the non-transient portions are possible.

Levine, Scott Nathan



Hybrid Vapor Compression Adsorption System: Thermal Storage Using Hybrid Vapor Compression Adsorption System  

SciTech Connect

HEATS Project: UTRC is developing a new climate-control system for EVs that uses a hybrid vapor compression adsorption system with thermal energy storage. The targeted, closed system will use energy during the battery-charging step to recharge the thermal storage, and it will use minimal power to provide cooling or heating to the cabin during a drive cycle. The team will use a unique approach of absorbing a refrigerant on a metal salt, which will create a lightweight, high-energy-density refrigerant. This unique working pair can operate indefinitely as a traditional vapor compression heat pump using electrical energy, if desired. The project will deliver a hot-and-cold battery that provides comfort to the passengers using minimal power, substantially extending the driving range of EVs.




Configurational Contribution to the Compression of Silicate Liquids  

NASA Astrophysics Data System (ADS)

Melting of silicates in the deep interior of planets has likely played an important role in their evolution. The segregation of silicate melts is controlled by the density contrast between melts and residual solids. Stolper et al. (1981) hypothesized that melts might be denser than their residues at high pressures due to the much larger compressibility of liquids than that of solids. Although the large compressibility of liquids is supported by ultrasonic measurements and static compression experiments using sink/float method, the compression mechanism of liquids is still not well understood. In general, equation of state of a material can be obtained by taking the volume derivative of the Helmholtz free energy. For a solid, free energy has two contributions, the potential energy of a static lattice, and the vibrational free energy (thermal contribution). Thus bulk modulus (the second derivative of free energy) of a solid at T=0 K is determined by the potential energy, while the vibrational part gives the temperature dependence. However, under compression atoms in a liquid can undergo structural rearrangement in addition to the uniform shortening of interatomic distances. Therefore another term, the configurational contribution, must be included in the liquid free energy. It is this contribution that leads to the different compression mechanism for liquids. In this work, we analyzed elastic properties determined by Brillouin spectroscopy, ultrasonic velocity measurements, and static compression experiments on solids, glasses, super- cooled liquids, and liquids for several silicate compositions including CaMgSi2O6, CaAl2Si2O8, Fe2SiO4, etc. We find that in the bulk modulus-density log-log plot (the slope of this plot is the Grüneisen-Anderson parameter), data for solids, glasses, and super-cooled liquids fall on the same straight line, while data for relaxed liquids fall on a distinctly different line. This means that the compression mechanisms for super-cooled liquids, glasses, and solids are essentially the same. Their differences in bulk modulus are mainly due to the volume difference (or bond length difference). However, unlike super-cooled liquids and glasses, configurational rearrangement plays an important role for the relaxed compression of liquids, which makes the bulk modulus of liquids further smaller. The percentages of configurational contribution to the total compressibility for different silicate liquids are then compared with the configurational entropy of the liquids to shed some light on the theoretical model of liquid compression.

Jing, Z.; Karato, S.



Image compression by cellular neural networks  

Microsoft Academic Search

This paper demonstrates how the cellular neural-network universal machine (CNNUM) architecture can be applied to image compression. We present a spatial subband image-compression method well suited to the local nature of the CNNUM. In case of lossless image compression, it outperforms the JPEG image-compression standard both in terms of compression efficiency and speed. It performs especially well with radiographical images

P. L. Venetianter; T. Roska



Fatigue crack growth in polymers subjected to fully compressive cyclic loads  

Microsoft Academic Search

It is experimentally demonstrated in this work that the application of cyclic compression loads to polymeric materials, specifically high-density polyethylene and polystyrene, results in the nucleation and propagation of stable fatigue cracks. The cracks grow at a progressively slower rate along the plane of the notch in a direction perpendicular to the far-field cyclic compression axis. The overall characteristics of

L. Pruitt; R. Hermann; S. Suresh



Aspiration in chest compression alone without mechanical ventilation in the head down position in dogs  

Microsoft Academic Search

Background: Previous work by the authors has shown that chest compressions alone without mechanical ventilation during cardiopulmonary resuscitation in the natural supine position was associated with pulmonary aspiration in dogs. The purpose of this investigation was to test the hypothesis that a head down position may prevent aspiration during chest compressions alone and whether oxygenation can be improved by simply

Bruno Jawan; Zu-Kong Chong; Hak-Kim Cheung; Yan-Yuen Poon; Yu-Feng Cheng; Han-Shiang Chen; Kwok-Wai Cheng; Chih-Shien Wang; Ju-Hao Lee



Using Compression to Understand the Distribution of Building Blocks in Genetic Programming Populations  

Microsoft Academic Search

Compression algorithms generate a predictive model of data, using the model to reduce the number of bits required to transmit the data (in effect, transmitting only the differences from the model). As a consequence, the degree of compression achieved provides an estimate of the level of regularity in the data. Previous work has investigated the use of these estimates to

Tuan Hao


On the crushing response of composite sandwich panels subjected to edgewise compression: experimental  

Microsoft Academic Search

In the present work the compressive properties, collapse modes and crushing characteristics of various types of composite sandwich panels were investigated in a series of edgewise compression tests. The tested sandwich panels were constructed trying four types of polymer foam core (more specifically PMI foam, two grades of linear PVC foam and polyurethane foam) and two types of FRP faceplate

A. G. Mamalis; D. E. Manolakos; M. B. Ioannidis; D. P. Papapostolou



Dynamic factors and force-weighting corrections influence estimates of cumulative vertebral joint compression  

Microsoft Academic Search

Estimates of cumulative load are typically based on a direct integration of instantaneous compressive loads. Recent evidence suggests that higher loads as well as smaller rest to work durations should receive greater importance in the calculation of cumulative compressive load, especially if insight into potential injury mechanisms is sought. The purpose of this investigation was to determine the effects that

Samuel J. Howarth; Tyson A. C. Beach; Jack P. Callaghan



Subjective testing results for still picture compression algorithms for international standardization  

Microsoft Academic Search

During 1987 and 1988, a joint group of ISO and CCITT has worked to create a world standard for data compression of still-frame color continuous-tone images. During this period, the adaptive discrete cosine transform (ADCT) was selected for final refinement from 12 proposed algorithms. Because the standard is required to provide either lossless or lossy compression, subjective image quality testing

Gregory Wallace; Roy Vivian; Henning Poulsen



Hierarchical Compression for Model-Checking CSP or How to Check 1020 Dining Philosophers for Deadlock  

Microsoft Academic Search

We have given details of how FDR2's compression works, and some simple examples of how it can expand the size of problem we can automatically check. At the time of writing we have not had time to carry out many evaluations of this new functionality on realistic-sized examples, but we have no reason to doubt that compression will allow comparable

A. W. Roscoe; Paul H. B. Gardiner; Michael Goldsmith; J. R. Hulance; D. M. Jackson; J. B. Scattergood



Performance optimization of a hybrid cooler combining vapor compression and natural circulation cycles  

Microsoft Academic Search

A hybrid cooler combining vapor compression and natural circulation cycles was developed for the cooling of telecommunication equipment in the cabinet-type base station of mobile communication. This hybrid cooler normally operates in the vapor compression mode at high ambient temperatures, but works in the natural circulation mode at low ambient temperatures by the thermosiphon principle. The performance of the hybrid

Sunil Lee; Hoon Kang; Yongchan Kim



Hysteresis Response of Lead Zirconate—Lead Nickel Niobate Ferroelectric Ceramic Under Compressive Stress  

Microsoft Academic Search

In this work, PZ–PNN ceramic was prepared by a columbite method and sintered at optimum temperature. The effect of uniaxial compressive stress on the hysteresis properties of PZ–PNN ceramics is investigated. The hysteresis loop and ferroelectric properties under the compressive stress of the ceramics are observed at stress up to 100 MPa using a compressometer in conjunction with a modified

W. C. Vittayakorn; N. Vittayakorn



Semi-confined compression of microfabricated polymerized biomaterial constructs  

NASA Astrophysics Data System (ADS)

Mechanical forces are critical parameters in engineering functional tissue because of their established influence on cellular behaviour. However, identifying ideal combinations of mechanical, biomaterial and chemical stimuli to obtain a desired cellular response requires high-throughput screening technologies, which may be realized through microfabricated systems. This paper reports on the development and characterization of a MEMS device for semi-confined biomaterial compression. An array of these devices would enable studies involving mechanical deformation of three-dimensional biomaterials, an important parameter in creating physiologically relevant microenvironments in vitro. The described device has the ability to simultaneously apply a range of compressive mechanical stimuli to multiple polymerized hydrogel microconstructs. Local micromechanical strains generated within the semi-confined hydrogel cylinders are characterized and compared with those produced in current micro- and macroscale technologies. In contrast to previous work generating unconfined compression in microfabricated devices, the semi-confined compression model used in this work generates uniform regions of strain within the central portion of each hydrogel, demonstrated here to range from 20% to 45% across the array. The uniform strains achieved simplify experimental analysis and improve the utility of the compression platform. Furthermore, the system is compatible with a wide variety of polymerizable biomaterials, enhancing device versatility and usability in tissue engineering and fundamental cell biology studies.

Moraes, Christopher; Zhao, Ruogang; Likhitpanichkul, Morakot; Simmons, Craig A.; Sun, Yu



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



The effect of timing of decompression on neurologic recovery and histopathologic findings after spinal cord compression in a rat model.  


Prior animal models have shown that rats sustaining 3-second immediate spinal cord compression had significantly better functional recovery and smaller lesion volumes than rats subjected to compression times of 1 hour, 6 hours, 3 weeks, and 10 weeks after spinal cord injury. We compare locomotor rating scales and spinal cord histopathology after 3 seconds and 10 minute compression times. . Ten rats were assigned into two early (3-second) and late (10-minute) compressive surgery groups. Compressive injury was produced using an aneurysmal clip method. Rats were followed-up for 11 weeks, and behavioral assessment was done by inclined plane test and tail-flick reflex. At the end of the study, the rats were sacrificed, and spinal cord specimens were studied in light and EM. Basso, Beattie and Bresnahan (BBB) locomotor rating scales were significantly better in the early compression group after the 4th week of evaluation (P<0.05) and persisted throughout the remainder of the study. Histopathology demonstrated decreased normal tissue, more severe gliosis and cystic formation in the late group compared to the early group (P<0.05). In EM study, injuries in the late group including injury to the myelin and axon were more severe than the early compression group, and there was more cytoplasmic edema in the late compression group. Spinal cord injury secondary to 3-second compression improves functional motor recovery, spares more functional tissue, and is associated with less intracellular edema, less myelin and axon damage and more myelin regeneration in rats compared to those with 10 minutes of compression. Inclined plane test and tail-flick reflex had no significant difference. PMID:23945885

Jazayeri, Seyed Behzad; Firouzi, Masoumeh; Abdollah Zadegan, Shayan; Saeedi, Niloufar; Pirouz, Elham; Nategh, Mohsen; Jahanzad, Issa; Mohebbi Ashtiani, Ahmad; Rahimi-Movaghar, Vafa



Novel approach for multidimensional data reconstruction and compression  

Microsoft Academic Search

In this paper we present a powerful approach for noisy data reconstruction and also for data compression based on our algorithms for tensor factorization and decomposition [10], [9]. This approach has many potential applications in computational neuroscience, multi-sensory, multidimensional data analysis and text mining. Our algorithms are locally stable and work well for sufficiently sparse data even if in the

Anh Huy PHAN; Andrzej CICHOCKI; Kim Sach NGUYEN



Recent achievements in lossless compression of hyperspectral data  

Microsoft Academic Search

Algorithms for compression of hyperspectral data are commonly evaluated on a readily available collection of Airborne Visible\\/Infrared Imaging Spectrometer (AVIRIS) images. The calibrated images collected in 1997 show sample value distributions which contain artificial regularities introduced by the conversion of raw data values to radiance units. Being optimal on images having flat histograms, classical DPCM methods do not work in

Bruno Aiazzi; Luciano Alparone; Stefano Baronti; Andrea Garzelli



Viscoelastic and compression fatigue properties of closed cell PVDF foam  

Microsoft Academic Search

This work illustrates the dynamical mechanical behaviour under cyclic fatigue and combined thermal–mechanical sinusoidal loading of a novel PVDF closed cell foam. The fatigue tests are carried out in control displacement and the specimens are statically loaded until a compression ratio of 50%, then cyclically loaded at various amplitudes. Viscoelastic tests are performed to obtain a master curve for the

N. Frioui; A. Bezazi; C. Remillat; F. Scarpa; J. P. Gomez



References on Compression of Freeze-Dried Foods.  

National Technical Information Service (NTIS)

This report attempts to assemble the references to the R&D work conducted in the area of freeze-dried and compressed foods. Sixty-eight technical reports with authors summaries, 69 journal articles and papers, 27 patents, and 17 specifications and Limited...

S. E. Wallen J. M. Tuomy G. C. Walker



Flame extinction in compressible flow  

NASA Astrophysics Data System (ADS)

The structure of the compressible stagnation flow at the forward point of a cylinder in a uniform stream is examined. Such flows are used in the laboratory to characterize the structure and stability limits of counterflow diffusion flames, where the fuel is emitted radially from the surface of the cylinder against the uniform approach flow. While hydrocarbon fuels are extinguished at relatively low strain rates, corresponding to low approach velocities, hydrogen requires much larger strain rates for extinction. The corresponding approach flow is in the compressible range and requires analysis as such. Solutions and estimates are developed for the cases of subsonic and supersonic flow. In particular, a Rayleigh-Janzen expansion of the potential function is carried out to six terms, using a symbolic manipulation language, and the analytical results are differentiated to obtain the strain field in subsonic flow. Compressibility is shown to decrease the strain rate for constant approach velocity and cylinder radius. This counter-intuitive result is shown to be a near-field phenomenon due to higher-order singularities; the strain further upstream is shown to increase. Estimates made for the case of supersonic flow indicate a lower level of strain compared with that in subsonic compressible flow. These results indicate that compressibility of the free stream offers a potential for increased flame stability. The conclusions are relevant to flame stability in high-speed combustors, such as those in supersonic combustion ramjets.

Correa, S. M.



Compressive matched-field processing.  


Source localization by matched-field processing (MFP) generally involves solving a number of computationally intensive partial differential equations. This paper introduces a technique that mitigates this computational workload by "compressing" these computations. Drawing on key concepts from the recently developed field of compressed sensing, it shows how a low-dimensional proxy for the Green's function can be constructed by backpropagating a small set of random receiver vectors. Then the source can be located by performing a number of "short" correlations between this proxy and the projection of the recorded acoustic data in the compressed space. Numerical experiments in a Pekeris ocean waveguide are presented that demonstrate that this compressed version of MFP is as effective as traditional MFP even when the compression is significant. The results are particularly promising in the broadband regime where using as few as two random backpropagations per frequency performs almost as well as the traditional broadband MFP but with the added benefit of generic applicability. That is, the computationally intensive backpropagations may be computed offline independently from the received signals, and may be reused to locate any source within the search grid area. PMID:22779458

Mantzel, William; Romberg, Justin; Sabra, Karim



With Weekly Exercise, Time Trumps Frequency  


... on this page, please enable JavaScript. With Weekly Exercise, Time Trumps Frequency No matter how they spread ... Preidt Friday, July 12, 2013 Related MedlinePlus Page Exercise and Physical Fitness FRIDAY, July 12 (HealthDay News) -- ...


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



A weekly cycle in atmospheric carbon dioxide  

NASA Astrophysics Data System (ADS)

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. Over the past twenty-five years, the variation of the mean values of MSR (as a function of day of the week) has been relatively stable. We speculate that the observed weekday/weekend variation in CO2 at Mauna Loa is the result of anthropogenic emissions on Hawaii and nearby sources. We do not detect a weekly cycle in daily CO2 concentration measured at South Pole, Antarctica. This methodology has applicability to a variety of datasets.

Cerveny, Randall S.; Coakley, Kevin J.



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 ( 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.".



Comparative gastrointestinal safety of weekly oral bisphosphonates  

PubMed Central

Summary Weekly bisphosphonates are the primary agents used to treat osteoporosis. Although these agents are generally well tolerated, serious gastrointestinal adverse events, including hospitalization for gastrointestinal bleed, may arise. We compared the gastrointestinal safety between weekly alendronate and weekly risedronate and found no important difference between new users of these agents. Introduction Weekly bisphosphonates are the primary agents prescribed for osteoporosis. We examined the comparative gastrointestinal safety between weekly bisphosphonates. Methods We studied new users of weekly alendronate and weekly risedronate from June 2002 to August 2005 among enrollees in a state-wide pharmaceutical benefit program for seniors. Our primary outcome was hospitalization for upper gastrointestinal bleed. Secondary outcomes included outpatient diagnoses for upper gastrointestinal disease, symptoms, endoscopic procedures, use of gastroprotective agents, and switching between therapies. We used Cox proportional hazard models to compare outcomes between agents within 120 days of treatment initiation, adjusting for propensity score quintiles. We also examined composite safety outcomes and stratified results by age and prior gastrointestinal history. Results A total of 10,420 new users were studied, mean age=79 years (SD, 6.9), and 95% women. We observed 31 hospitalizations for upper gastrointestinal bleed (0.91 per 100 person-years) within 120 days of treatment initiation. Adjusting for covariates, there was no difference in hospitalization for upper gastrointestinal bleed among those treated with risedronate compared with alendronate (HR, 1.12; 95%CI, 0.55 to 2.28). Risedronate switching rates were lower; otherwise, no differences were observed for secondary or composite outcomes. Conclusions We found no important difference in gastrointestinal safety between weekly oral bisphosphonates.

Katz, J. N.; Brookhart, M. A.; Sturmer, T.; Stedman, M. R.; Levin, R.; Solomon, D. H.



Rearranged Work Schedules.  

National Technical Information Service (NTIS)

The report review the background of the schedule innovations in regard to work in 2 companies, which went from the traditional nine to five, 5-day per week schedule. The report only presents 2 case studies based on the 70 interviews conducted.

R. L. Nuttal H. Madfis D. Polit J. Buckley



Compressibility of zinc sulfide nanoparticles  

SciTech Connect

We describe a high-pressure x-ray diffraction (XRD) study of the compressibility of several samples of ZnS nanoparticles. The nanoparticles were synthesized with a range of sizes and surface chemical treatments in order to identify the factors that determine nanoparticle compressibility. Refinement of the XRD data revealed that all ZnS nanoparticles in the nominally cubic (sphalerite) phase exhibited a previously unobserved structural distortion under ambient conditions that exhibited, in addition, a dependence on pressure. Our results show that the compressibility of ZnS nanoparticles increases substantially as the particle size decreases, and we propose an interpretation based upon the available mechanisms of structural compliance in nanoscale vs bulk materials.

Gilbert, B. [Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Zhang, H.; Chen, B.; Banfield, J. F. [Department of Earth and Planetary Sciences, University of California-Berkeley, Berkeley, California 94720 (United States); Kunz, M. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Huang, F. [Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, People's Republic of China (China)



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



Compressed microtubules: Splitting or buckling  

NASA Astrophysics Data System (ADS)

Microtubule (MT) is the mechanically strongest cytoskeletal element in eukaryotic cells and plays a key role in maintaining cell's geometrical shape by bearing compressive forces. MTs are highly dynamic, and ``dynamic instability'' is referred to the switch between polymerization and depolymerization phases (the latter is characterized by splitting of protofilaments at the plus end). A micromechanics model is proposed here to study whether an axially compressed microtubule, protected by a ``cap'' consisted of a few layers of strongly bonded GTP dimers at the plus end, can split prior to overall buckling. Our basic conclusion is that compression-driven splitting of a capped microtubule can happen prior to overall buckling when the microtubule is very short (typically shorter than few hundreds of nanometers). For example, compression-driven splitting from middle of a capped microtubule can happen prior to buckling when the length of microtubule is shorter than a few hundreds of nanometers. In addition, for capped microtubules shorter than 125-180 nm (depending on specific values of axial Young's modulus and adhesion energy between protofilaments), mechanical compression will cause splitting of the microtubule at its plus end prior to overall buckling. On the other hand, however, for microtubules of length longer than 0.3-0.75 micron (depending on specific values of axial Young's modulus and adhesion energy between protofilaments), the present model shows that a cap composed of even one single layer of GTP dimers is sufficient to prevent compression-driven splitting prior to buckling, in agreement with the known observations that dynamic instability or splitting of moderately long microtubules could happen only when the cap is completely lost at the plus end.

Jin, M. Z.; Ru, C. Q.



Compression therapy for chronic venous insufficiency.  


Compression therapy provides a means to treat venous stasis, venous hypertension, and venous edema. Different methods of compression therapy have been described periodically over the last 2,000 years. In addition to static compression, specialized compression pumps have been developed and a technique of massage called manual lymphatic drainage has emerged to treat primary and secondary lymphedema. Objectives of compression therapy are to reduce the swollen limb to minimum size, maintain that size, and allow the patient to participate in the care of his limb whenever possible. Reduction therapy is achieved by limb elevation, compression pumps as necessary, and compression wraps. Maintenance therapy largely consists of compression wraps or compression stockings. Nonelastic devices have found a place in treating severe lymphedema but it should be emphasized that periodic follow-up must be done during maintenance therapy so that adjunctive maintenance measures can be added as needed. PMID:15791552

Felty, Cindy L; Rooke, Thom W



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)



78 FR 30723 - National Safe Boating Week, 2013  

Federal Register 2010, 2011, 2012, 2013

...Proclamation 8981--National Safe Boating Week, 2013 Proclamation 8982--Emergency Medical Services Week, 2013 Proclamation 8983--World Trade Week, 2013 Proclamation 8984--Armed Forces Day, 2013 Memorandum...



Compressing Data by Source Separation  

NASA Astrophysics Data System (ADS)

We interpret source separation of hyperspectral data as a way of applying lossy compressing. In settings where datacubes can be interpreted as a linear combination of source spectra and their abundances and the number of sources is small, we try to quantify the trade-offs and the benefits of source separation and its implementation with non-negative source factorisation. While various methods to implement non-negative matrix factorisation have been used successfully for factoring hyperspectral images into physically meaningful sources which linearly combine to an approximation of the original image. This is useful for modelling the processes which make up the image. At the same time, the approximation opens up the potential for a significant reduction of the data by keeping only the sources and their corresponding abundances, instead of the original complete data cube. This presentation will try to explore the potential of the idea and also to establish limits of its use. Formally, the setting is as follows: we consider P pixels of a hyperspectral image which are acquired at L frequency bands and which are represented as a PxL data matrix X. Each row of this matrix represents a spectrum at a pixel with spatial index p=1..P; this implies that the original topology may be disregarded. Since we work under the assumption of linear mixing, the p-th spectrum, 1<=p<=P, can be expressed as a linear combination of r, 1<=r<=R, source spectra. Thus, X=AxS+E, E being an error matrix to be minimised, and X, A, and S only have non-negative entries. The rows of matrix S are the estimations of the R source spectra, and each entry of A expresses the contribution of the r-th component to the pixel with spatial index p. There are applications where we may interpret the rows of S as physical sources which can be combined using the columns of A to approximate the original data. If the source signals are few and strong (but not even necessarily meaningful), the data volume that has to be transmitted or looked at can be reduced significantly.

Schmidt, A.; Tréguier, E.; Schmidt, F.; Moussaoui, S.



Preliminary lossless compression results with Michelson interferometer data  

NASA Astrophysics Data System (ADS)

The next-generation GOES-R (Geostationary Operational Environmental Satellite) HES (Hyperspectral Environmental Suite) Sounder will be either a grating or interferometer design. The HES will be able to provide hourly atmospheric soundings with spatial resolutions of 5 ~ 10 km with higher accuracy than the current geostationary sounder. A number of GOES-R products will be made from the HES data, this information will help both in forecasting and numerical model initializations. Extensive research has been done with lossless data compression with data from a grating-type ultraspectral instrument. NAST-I aircraft data is chosen for testing data from interferometers until IASI (Infrared Atmospheric Sounding Interferometer) and CrIS (Cross-track Infrared Sounder) are available. Preliminary work at CIMSS with lossless data compression of Michelson Interferometer data achieves compression ratios (CR) above 5.

Schmit, Timothy J.; Huang, Bormin; Sriraja, Y.; Huang, Hung-Lung



Thermoacoustic compression based on alternating to direct gas flow conversion  

NASA Astrophysics Data System (ADS)

We present a remarkable thermoacoustically driven compression effect based on the conversion of gas flow from an alternating state to a direct state. The alternating gas flow is generated by the thermoacoustic effect in thermoacoustic engines, whereas direct gas flow is achieved by means of the flow rectification effect of check valves. A demonstrative thermoacoustic compressor consisting of two standing-wave thermoacoustic engines, two reservoirs, and three check valves is constructed for experimental investigation. With nitrogen as a working gas and an initial pressure of 2.4 MPa in all components, a usable pressure difference of 0.4 MPa is achieved, with the average gas pumping rate reaching 2.85 Nm3/h during the first 3 s of the compression process. The simple mechanical structure and thermally driven nature of the compressor show potential in gas compression, power generation, and refrigeration applications.

Sun, D. M.; Wang, K.; Xu, Y.; Shen, Q.; Zhang, X. J.; Qiu, L. M.



Compressible Flow Modeling with the Lagrangian Averaged Navier-Stokes Equations.  

National Technical Information Service (NTIS)

We have derived, in a mathematically precise way, Lagrangian- averaged models for incompressible and compressible flow. This work has now appeared in the SIAM Journal 'Multiscale Modeling and Simulation;' Bhat, Fetecan, Marsden Mohseni, and West. That wor...

J. E. Marsden K. Mohseni P. E. Dimotakix



Operability Test Report for 241-T compressed air system and heat pump.  

National Technical Information Service (NTIS)

This Operability Test Report (OTR) documents the results of functional testing performed on the operating parameters of the 241-T-701 Compressed Air System. The System was successfully installed and tested per work package 2W-92-01172.

R. D. Freeman



Teaching Time-Space Compression  

ERIC Educational Resources Information Center

|Time-space compression shows students that geographies are plastic, mutable and forever changing. This paper justifies the need to teach this topic, which is rarely found in undergraduate course syllabi. It addresses the impacts of transportation and communications technologies to explicate its dynamics. In summarizing various conceptual…

Warf, Barney



Compression différentielle de transitoires bruités  

Microsoft Academic Search

The analysis and compression of noisy transient signals are handled via methods stemming from elementary differential algebra, noncommutative algebra and operational calculus. The efficiency of our approach is illustrated by an academic example and a more concrete case-study which is a musical signal. To cite this article: M. Fliess et al., C. R. Acad. Sci. Paris, Ser. I 339 (2004).

Michel Fliess; Cédric Join; Mamadou Mboup; Hebertt Sira-Ramírez



Optimizing Queries on Compressed Bitmaps  

Microsoft Academic Search

Bitmap indices are used by DBMS's to accelerate decision support queries. A significant advantage ofbitmap indices is that complex logical selection operations can be performed very quickly, by performingbit-wise AND, OR, and NOT operators. Although bitmap indices can be space inefficient for highcardinality attributes, the space use of compressed bitmaps compares well to other indexing methods.Oracle and Sybase IQ are

Sihem Amer-yahia; Theodore Johnson



Experiments in text file compression  

Microsoft Academic Search

A system for the compression of data files, viewed as strings of characters, is presented. The method is general, and applies equally well to English, to PL\\/I, or to digital data. The system consists of an encoder, an analysis program, and a decoder. Two algorithms for encoding a string differ slightly from earlier proposals. The analysis program attempts to find

Frank Rubin



Compressed natural gas dispensing system  

Microsoft Academic Search

A system and method for dispensing compressed gas from a storage tank is disclosed in which the temperature and pressure in the tank is measured before and after the dispensing cycle and electric signals representative of these values are applied to a processor\\/computer which is programmed to compute from these signals the volume of gas dispensed.

H. W. Fisher; E. E. Hrivnak



Ultrahigh Vacuum Twist Compression Apparatus  

Microsoft Academic Search

A new apparatus is described which is used for bonding of metals in ultrahigh vacuum by the twist compression technique. It is shown that adhesion between hard metal specimens can be readily measured in ultrahigh vacuum after some initial mechanical abrasion of the surfaces, while adhesion tests in air at atmospheric pressure do not yield measurable adhesion coefficients. Experimental results

J. M. Bradford; K. B. Wear; M. E. Sikorski



Compact XML grammar based compression  

Microsoft Academic Search

Extensible Markup Language (XML) is the standard format for content representation and sharing on the Web. XML is a highly verbose language, especially regarding the duplication of meta-data in the form of elements and attributes. As XML content is becoming more widespread so is the demand to compress XML data volume. This paper presents a new grammar, called D-grammar, which

S. Harrusi; A. Averbuch; A. Yehudai


Compressive Creep of Dental Composites  

Microsoft Academic Search

The creep compliance curves for P-10, Adaptic, and Silar composite materials were obtained at 23°C, 37°C, and 50°C and at a number of initial stress levels ranging from 5 to 75% of their compressive strengths. The creep compliance curves were characterized by large instantaneous compliances, followed by retarded strain compliances with very minimal viscous flow. Rupturing occurred only at the

M. S. Bapna; H. J. Mueller; R. Knoeppel



Compression-aware demosaicing methods  

Microsoft Academic Search

In many digital color-image systems, most notably digital cameras, raw data from the sensor is processed to produce a pleasing image. One of the main steps in this process is demosaicing, which is the process of interpolating the raw data into a full color image. The resulting image is in turn compressed to enable compact storage. Each of these two

Zachi Z. Baharav; Ramakrishna Kakarala



Time Series Compressibility and Privacy  

Microsoft Academic Search

In this paper we study the trade-offs between time series compressibility and partial information hiding and their fun- damental implications on how we should introduce uncer- tainty about individual values by perturbing them. More specifically, if the perturbation does not have the same com- pressibility properties as the original data, then it can be detected and filtered out, reducing uncertainty.

Spiros Papadimitriou; Feifei Li; George Kollios; Philip S. Yu



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



Language Acquisition and Data Compression  

Microsoft Academic Search

Statistical data compression requires a stochastic language modelwhich must rapidly adapt to new data as it is encountered. A grammaticalinference engine is introduced which satisfies this requirement;it is able to discover structure in arbitrary data using nothing morethan the predictions of a simple trigram model. We show that compressionmay be used as an alternative to perplexity for languagemodel evaluation, and

Jason L. Hutchens



The Neutralized Drift Compression Experiment  

NASA Astrophysics Data System (ADS)

The most recent, and highly innovative, proposal for a next, integrated beam experiment in the U.S. Heavy Ion Fusion Virtual National Laboratory (HIF-VNL) is the Neutralized Drift Compression Experiment (NDCX). NDCX will develop novel, still unexplored beam manipulation techniques in order to establish the physics limits on compression of heavy ion beams for creating high energy density matter and fusion ignition conditions. As a major advance for the HIF-VNL, NDCX could also provide significant beam pulse energy on target (10^11 J/m^3). The main components of NDCX are discussed, in particular a new injector concept, the load-and-fire injector, and the neutralized drift compression section. NDCX will compress the beam within neutralizing plasma, therefore significantly extending the transportable beam current into high-intensity regimes not reachable in the absence of background plasma. To validate these essential components experimentally NDCX will be built in several phases, which are described in more detail.

Leitner, M. A.; Anders, A.; Bieniosek, F. M.; Eylon, S.; Greenway, W. G.; Henestroza, E.; Logan, B. G.; Roy, P. K.; Shuman, D. B.; Vanecek, D. L.; Waldron, W. L.; Yu, S. S.; Rose, D. V.; Thoma, C.; Welch, D. R.; Davidson, R. C.; Efthimion, P. C.; Gilson, E. P.; Kaganovich, I.; Sefkow, A. B.; Barnard, J. J.; Sharp, W. M.



Compound-Compressible Nozzle Flow.  

National Technical Information Service (NTIS)

A one-dimensional theory based upon fundamental flow relationships is presented for analyzing the behavior of one or more gas streams flowing through a single nozzle. This compound-compressible flow theory shows that the behavior of each stream is influen...

A. Bernstein C. Hevenor



Compressibility of cold catalyzed matter  

Microsoft Academic Search

The properties of cold catalyzed matter (CCM) of density near and above the density characteristic of the central region of heavy atomic nuclei are of fundamental importance for the physics of neutron stars. In this paper the compression modulus of CCM (an electrically neutral, spatially homogeneous mixture of electrons, neutrons, and protons at a temperature of 0 K) is studied

P. Haensel



Lightness compression and hue changes.  


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



Formulation Development of Metoprolol Succinate and Hydrochlorothiazide Compression Coated Tablets.  


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 release of metoprolol succinate in stomach. 32 full factorial design was employed for optimization of amount of polymers to achieve extended release of drug. The percentage drug release at given time; Q3, Q6, Q10, Q22; were selected as dependent variable. Core and compression coated tablets were evaluated for pharmaco-technical parameters. In vitro drug release of optimized batch was found to comply Pharmacopoeial specifications. Desired release of metoprolol succinate was obtained by proper combination of HPMC having high gelling capacity and polyethylene oxide having quick gelling capacity. The mechanism of drug release for 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



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.



Radio-Frequency Pulse Compression for Linear Accelerators.  

NASA Astrophysics Data System (ADS)

Recent efforts to develop plans for an electron -positron linear collider with center-of-mass energy approaching a TeV have highlighted the need for sources capable of delivering hundreds of megawatts of peak rf drive power at X-band frequencies. This need has driven work in the area of rf pulse compression, which enhances the peak power available from pulsed rf tubes by compressing their output pulses in time, accumulating the available energy into shorter pulses. The classic means of rf pulse compression for linear accelerators is SLED. This technique is described, and the problem it presents for multibunch acceleration explained. Other pulse compression schemes, capable of producing suitable output pulses are explored, both theoretically and experimentally, in particular Binary Pulse Compression and SLED-II. The merits of each are considered with regard to gain, efficiency, complexity, size and cost. The development of some novel system components, along with the theory behind their design, is also discussed. The need to minimize copper losses in long waveguide runs led to the use of the circular TE_{01} propagation mode in over-moded guide, requiring much attention to mechanisms of coupling power between modes. The construction and commissioning of complete, high-power pulse compression systems is reported on, as well as their use in the testing of X-band accelerating structures, which, along with the X-band klystrons used, were developed at SLAC in parallel with the pulse compression work. The focus of the dissertation is on SLED-II, the favored scheme in some current linear accelerator designs. In addition to our experimental results, practical implementation considerations and design improvements are presented. The work to date has led to detailed plans for SLED-II systems to be used in the Next Linear Collider Test Accelerator, now under construction at SLAC. The prototype of the upgraded system is near completion. Descriptions of various rf pulse-compression techniques besides the aforementioned three, including those pursued at institutions other than SLAC, are included to give a broad taste for the field and a sense of future possibilities.

Nantista, Christopher Dennis


Compressed Sensing and its Applications in Imaging  

NASA Astrophysics Data System (ADS)

Compressed sensing is a new sampling theory which allows reconstructing signals using sub-Nyquist measurements/sampling. This can significantly reduce the computation required for image/video acquisition/encoding, at least at the sensor end. Compressed sensing works on the concept of sparsity of the signal in some known domain, which is incoherent with the measurement domain. We exploit this technique to build a single pixel camera based on an optical modulator and a single photosensor. Random projections of the signal (image) are taken by optical modulator, which has random matrix displayed on it, corresponding to the measurement domain (random noise). This randomly projected signal is collected on the photosensor and later used for reconstructing the signal. In this scheme we are making a tradeoff between the spatial extent of sampling array and a sequential sampling over time with a single detector. In addition to this method, we will also demonstrate a new design which overcomes this shortcoming by parallel collection of many random projections simultaneously. Applications of this technique in hyperspectral and infrared imaging will be discussed.

Takhar, Dharmpal; Sun, Ting; Laska, Jason; Duarte, Marco; Baraniuk, Richard; Kelly, Kevin



Compressive imaging: hybrid measurement basis design.  


The inherent redundancy in natural scenes forms the basis of compressive imaging where the number of measurements is less than the dimensionality of the scene. The compressed sensing theory has shown that a purely random measurement basis can yield good reconstructions of sparse objects with relatively few measurements. However, additional prior knowledge about object statistics that is typically available is not exploited in the design of the random basis. In this work, we describe a hybrid measurement basis design that exploits the power spectral density statistics of natural scenes to minimize the reconstruction error by employing an optimal combination of a nonrandom basis and a purely random basis. Using simulation studies, we quantify the reconstruction error improvement achievable with the hybrid basis for a diverse set of natural images. We find that the hybrid basis can reduce the reconstruction error up to 77% or equivalently requires fewer measurements to achieve a desired reconstruction error compared to the purely random basis. It is also robust to varying levels of object sparsity and yields as much as 40% lower reconstruction error compared to the random basis in the presence of measurement noise. PMID:21643389

Ashok, Amit; Neifeld, Mark A



Frequency extrapolation by nonconvex compressive sensing  

SciTech Connect

Tomographic imaging modalities sample subjects with a discrete, finite set of measurements, while the underlying object function is continuous. Because of this, inversion of the imaging model, even under ideal conditions, necessarily entails approximation. The error incurred by this approximation can be important when there is rapid variation in the object function or when the objects of interest are small. In this work, we investigate this issue with the Fourier transform (FT), which can be taken as the imaging model for magnetic resonance imaging (MRl) or some forms of wave imaging. Compressive sensing has been successful for inverting this data model when only a sparse set of samples are available. We apply the compressive sensing principle to a somewhat related problem of frequency extrapolation, where the object function is represented by a super-resolution grid with many more pixels than FT measurements. The image on the super-resolution grid is obtained through nonconvex minimization. The method fully utilizes the available FT samples, while controlling aliasing and ringing. The algorithm is demonstrated with continuous FT samples of the Shepp-Logan phantom with additional small, high-contrast objects.

Chartrand, Rick [Los Alamos National Laboratory; Sidky, Emil Y [UNIV OF CHICAGO; Pan, Xiaochaun [UNIV OF CHICAGO



A simple method for compressible multifluid flow  

SciTech Connect

A simple second order accurate and fully Eulerian numerical method is presented for the simulation of multifluid compressible flows, governed by the stiffened gas equation of state, in hydrodynamic regime. The numerical method relies on a second order Godunov-type scheme, with approximate Riemannn solver for the resolution of conservation equations, and a set of nonconservative equations. It is valid for all mesh points and allows the resolution of interfaces. This method works for an arbitrary number of interfaces, for breakup and coalescence. It allows very high density ratios (up to 1,000). It is able to compute very strong shock waves (pressure ratio up to 10{sup 5}). Contrary to all existing schemes (which consider the interface as a discontinuity) the method considers the interface as a numerical diffusion zone as contact discontinuities are computed in compressible single phase flows, but the variables describing the mixture zone are computed consistently with the density, momentum and energy. Several test problems are presented in one, two and three dimensions. This method allows, for example, the computation of the interaction of a shock wave propagating in a liquid with a gas cylinder, as well as Richtmeyer-Meshkov instabilities, or hypervelocity impact, with realistic initial conditions. The authors illustrate the method with the Rusanov flux. However, the same principle can be applied to a more general class of schemes.

Saurel, R.; Abgrall, R.



Math Forum Technology Problems of the Week  

NSDL National Science Digital Library

Technology Problems of the Week (tPoWs) are freely accessible problem-solving challenges, modeled on the Math Forumâs Problems of the Week, that take advantage of interactive mathematics tools such as Java applets, TI-Nspireâ¢, The Geometer's Sketchpad®, Fathomâ¢, or spreadsheets. A login is required. Teachers may choose a free class membership, providing the ability to create classes, create student logins, and use the Math Forumâs online mentoring and feedback system or choose a free individual membership, providing individual access to view the problems as well as any available teacher resources. Free student memberships are also available. Problems include hints and answer checks.



Weekly precipitation cycles? Lack of evidence from United States surface stations  

Microsoft Academic Search

Previous work has inferred a relationship between human activity and the occurrence and amount of precipitation through examining possible weekly cycles in precipitation. Daily precipitation records for 219 surface observing stations in the United States for the 42-year period 1951–1992 are investigated for weekly cycles in precipitation. Results indicate that neither the occurrence nor amount of precipitation significantly depends upon

David M. Schultz; Santtu Mikkonen; Ari Laaksonen; Michael B. Richman



Changes from weekly backward to quicker forward rotating shift systems in the steel industry  

Microsoft Academic Search

Two intervention studies in the steel industry are presented. One experimental group (E1) changed from a discontinuous weekly backward (advancing) to a quicker forward (delaying) rotating shift system. The second experimental group (E2) first worked in a weekly backward rotating and then in a quicker forward rotating shift system. These experimental groups and two control groups (not changing their shift

Peter Knauth; Sonia Hornberger



Effects of 8-Week Training on Aerobic Capacity and Swimming Performance of Boys Aged 12 Years  

ERIC Educational Resources Information Center

|Study aim: To assess the effects of 8-week endurance training in swimming on work capacity of boys aged 12 years. Material and methods: The following groups of schoolboys aged 12 years were studied: untrained control (UC; n = 14) and those training swimming for two years. The latter ones were subjected to 8-week training in classical style (CS; n…

Zarzeczny, Ryszard; Kuberski, Mariusz; Deska, Agnieszka; Zarzeczna, Dorota; Rydz, Katarzyna; Lewandowska, Anna; Balchanowski, Tomasz; Bosiacki, Janusz



Tensile and compressive behavior of Ti-based bulk metallic glass composites  

NASA Astrophysics Data System (ADS)

This article focuses on the tensile and compressive characteristics of a Ti-based bulk metallic glass composite (BMGC). It is found that the yield stress, maximum strength, and fracture strain are 1380 MPa, 1516 MPa, and 4.3% for uniaxial tension, but 1580 MPa, 4010 MPa, and 29% for uniaxial compression, respectively. The composite displays a linear "work hardening" capacity under compression; however, the "work softening" behavior is observed in the true engineering stress-strain curve upon tensile loading. The fracture surfaces of specimens also exhibit dissimilar properties under the different loadings.

Wang, Yong-sheng; Hao, Guo-jian; Lin, Jun-pin



Compressibility and Fugacity of Gaseous Hydrogen.  

National Technical Information Service (NTIS)

The concept of fugacity is explained. Application of compressibility and fugacity data in hydrogen embrittlement calculations is discussed. Equations of state are reviewed. Compressibility factors and fugacity coefficients are calculated. A best estimate ...

H. P. Vanleeuwen



Industrial Compressed Air Supply System Efficiency.  

National Technical Information Service (NTIS)

This project, under contract from California Energy Commission, developed the CASE (Compressed Air Supply Efficiency) Index as a stand-alone value for compressor central plant efficiency. This Index captures the overall efficiency of a compressed air syst...

B. Joseph



Multiresolution Distance Volumes for Progressive Surface Compression.  

National Technical Information Service (NTIS)

We present a surface compression method that stores surfaces as wavelet-compressed signed-distance volumes. Our approach enables the representation of surfaces with complex topology and arbitrary numbers of components within a single multiresolution data ...

D. E. Laney M. Bertram M. A. Duchaineau N. L. Max



Compression of Mercury to High Pressure.  

National Technical Information Service (NTIS)

A method for calculating volume results from high pressure acoustic data was developed which is not limited to small compressions by the assumption of a constant ratio of isothermal to adiabatic compressibility. This method thereby extends the useful rang...

L. A. Davis



Critical Evaluation of 4Week Incubation for Fungal Cultures: Is the Fourth Week Useful?  

Microsoft Academic Search

To determine the benefit of a 4-week incubation for mycology cultures, we evaluated all positive cultures dur- ing the fourth week of incubation in a 1-year period. Of 3,855 positive mycology cultures (yeast, 82%; molds, 18%), 62 (1.6%) were positive during the fourth week (yeast, 42%; molds, 58%). Only 15 of the 62 cultures (24%) were considered clinically relevant (2





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



A data compression algorithm suitable for JASMINE  

NASA Astrophysics Data System (ADS)

We investigate data compression algorithm for astronomical satellite mission JASMINE. We are required to use lossless compression algorithms for scientific data. We cannot use lossy compression schemes which recently develop with the advance of internet technologies. Astronomical data is mainly image data, and it is binary data. Consequently, we must use lossless binary compression algorithms. Furthermore, CPU power is very limited in satellite mission. We conclude that combination of Golomb-Rice codes and Karhunen-Loeve transformation is suitable for JASMINE data.

Yamada, Yoshiyuki; Ueda, Seiji; Okumura, Haruhiko; Yano, Taihei; Gouda, Naoteru



Axial compressive fracture of carbon fibers  

Microsoft Academic Search

The axial compressive strength was measured on single-filaments of polyacrylonitrile and pitch-based carbon fibers. The compressive fracture mechanism of carbon fibers was investigated based on the crystallite and the microvoid structures characterized with X-ray scattering. The distribution of the compressive strength at a fixed fiber length, and the length dependence of the average compressive strength were much smaller than those

M. Nakatani; M. Shioya; J. Yamashita



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...



Twice weekly prophylactic therapy in haemophilia A  

Microsoft Academic Search

Factor VIII-containing materials were administered to four severely affected haemophiliacs twice weekly in doses calculated to raise the factor VIII level to either 15% or 30% of average normal. The pooled results from those patients with statistically similar baseline bleeding frequencies showed a significant reduction in bleeding frequency on both doses in the first 48 hours. The 30% dose produced

A Aronstam; P J Kirk; J McHardy; J W Culver-James; D S McLellan; P Turk; S G Rainsford; M Slattery



Sea/River Week Career Profiles.  

ERIC Educational Resources Information Center

|The aim of these materials is to interest students in jobs related to Alaska's natural resources. They coordinate with the Sea Week curriculum and the Alaska vocational state model curriculum in renewable natural resources in agriculture. Each of the 2-page career profiles includes a brief description of a person's job along with that person's…

Alaska State Dept. of Education, Juneau. Div. of Adult and Vocational Education.


This Week @ Nasa, November 1, 2013  

NASA Website

“Launch day approaches for NASA’s next Mars mission …” “A show of power from our Sun …” “And activity picks up on The International Space Station …Those are some of the stories trending, This Week at NASA!” Mars mission briefed - KSC During a news ...


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.



Science week: May 11”17  

NASA Astrophysics Data System (ADS)

National Science Week, an event launched last year by the National Science Foundation (NSF), will be observed thi s year from May 11 to May 17, 1986. In support of this effort, NSF is urging individuals or organizations to sponsor science and math competitions or fairs, arrange "open house" events at research facilities, organize educational programs and scientific demonstrations, and arrange or participate in other activities. National Science Week is intended to increase public awareness and understanding of science and technology and to encourage young people in the United States to become more involved with and consider careers in science and mathematics. Educational packets will be made available to schools, public libraries, and science museums. The corporate sponsors of National Science Week are the Amoco Foundation, the Atlantic Richfield Foundation, the Dow Chemical Company Foundation, the DuPont Company, the Eastman Kodak Company, the General Electric Foundation, and IBM. For more information, write to National Science Week '86, c/o National Science Foundation, 1800 G Street, N.W., Washington, DC 20550 (telephone: 1-800-227-SEEK).


National Women's History Week Curriculum Guide.  

ERIC Educational Resources Information Center

Designed for elementary and secondary level use, the ideas, materials, and resources in this guide are intended to facilitate teachers' first efforts at expanding the study of women in U.S. history. The cross-cultural guide provides introductory information and suggestions to help develop classroom observances for the National Women's History Week

Women's Support Network, Inc., Santa Rosa, CA.


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



Telling the Public--It's Science Week  

ERIC Educational Resources Information Center

|This article describes an opportunity to engage the public in demonstrating and explaining some aspects of science. About 10 years ago, the author met Peter Evennett in the ASE Conference exhibition. Peter was a member of the Leeds Philosophical and Literary Society and currently its president. As a contribution to "Science Week" (which dates…

Auty, Geoff



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 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...



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


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.


Robust retrieval from compressed medical image archives  

Microsoft Academic Search

Paper addresses the computational aspects of extracting important features directly from compressed images for the purpose of aiding biomedical image retrieval based on content. The proposed method for treatment of compressed medical archives follows the JPEG compression standard and exploits algorithm based on spacial analysis of the image cosine spectrum coefficients amplitude and location. The experiments on modality-specific archive of

Denis N. Sidorov; Jean F. Lerallut; Jean-Pierre Cocquerez; Joaquin Azpiroz



Test Pattern Compression Based on Pattern Overlapping  

Microsoft Academic Search

This paper describes a test data compression method based on pattern overlapping. We report here improvements that have been done on the test pattern compaction and compression algorithm called COMPAS. This algorithm reorders and compresses test patterns previously generated in an ATPG in such a way that they are well suited for decompression by the scan chains in the embedded

Jiri Jenícek; Ondrej Novák



A New Compression Method for FITS Tables  

Microsoft Academic Search

As the size and number of FITS binary tables generated by astronomical observatories increases, so does the need for a more efficient compression method to reduce the amount disk space and network bandwidth required to archive and download the data tables. We have developed a new compression method for FITS binary tables that is modeled after the FITS tiled-image compression

W. Pence; R. Seaman; R. L. White



VSA-based Fractal Image Compression  

Microsoft Academic Search

Spiral Architecture (SA) is a novel image structure which has hexagons but not squares as the basic elements. Apart from many other advantages in image processing, SA has shown two unbeatable characters that have potential to improve image compression performance, namely, Locality of Pixel Density and Uniform Image Partitioning. Fractal image compression is a relatively recent image compression method which

Huaqing Wang; Meiqing Wang; Tom Hintz; Qiang Wu; Xiangjian He


Data compression device for SAR application  

Microsoft Academic Search

On board data compression techniques for synthetic aperture radar are of great importance for reducing the high data rate of wide swath, high resolution SAR. One of the most efficient compression techniques for SAR raw data has been developed and applied for the Magellan Mission. The compression ratio of Magellan 8 to 2 put a strong limit on signal to

R. Bertoni; L. Di Paolo; R. Di Julio; F. Impagnatiello; F. Quaranta



Manufacture and compression properties of syntactic foams  

Microsoft Academic Search

A study has been made of the processability, bulk density, and uniaxial compression properties of a syntactic foam system with varying volume fractions of phenolic microballoons. Short-term compression tests showed that the compression yield strength and initial tangent modulus of elasticity were linearly dependent on the bulk density (and the volume fraction of microballoons). The microballoon concentration and resin binder

P. Bunn; J. T. Mottram



Fast Stereo Matching in Compressed Video  

Microsoft Academic Search

In this paper we present new algorithms that exploit compressed image data to achieve coarse stereo reconstructions in a real-time environment. Others have shown large gains from processing image streams in compressed form, and we extend those results to address the stereo correspondence problem. We show that it is possible to obtain stereo matches between two frames of a compressed

Michael S. Brown; W. Brent Seales



Natural language insensitive short textual string compression  

Microsoft Academic Search

There are applications (such as Internet search engines) where short textual strings, for example abstracts or pieces of Web pages, need to be compressed independently of each other. The usual adaptive compression algorithms perform poorly on these short strings due to the lack of necessary data to learn. In this manuscript, we introduce a compression algorithm targeting short text strings;

Cornel Constantinescu; Jennifer Q. Trelewicz; Ronald B. Arps



The structure of DMC [dynamic Markov compression  

Microsoft Academic Search

The popular dynamic Markov compression algorithm (DMC) offers state-of-the-art compression performance and matchless conceptual simplicity. In practice, however, the cost of DMC's simplicity and performance is often outrageous memory consumption. Several known attempts at reducing DMC's unwieldy model growth have rendered DMC's compression performance uncompetitive. One reason why DMC's model growth problem has resisted solution is that the algorithm is

S. Bunton



Finite scale equations for compressible fluid flow  

SciTech Connect

Finite-scale equations (FSE) describe the evolution of finite volumes of fluid over time. We discuss the FSE for a one-dimensional compressible fluid, whose every point is governed by the Navier-Stokes equations. The FSE contain new momentum and internal energy transport terms. These are similar to terms added in numerical simulation for high-speed flows (e.g. artificial viscosity) and for turbulent flows (e.g. subgrid scale models). These similarities suggest that the FSE may provide new insight as a basis for computational fluid dynamics. Our analysis of the FS continuity equation leads to a physical interpretation of the new transport terms, and indicates the need to carefully distinguish between volume-averaged and mass-averaged velocities in numerical simulation. We make preliminary connections to the other recent work reformulating Navier-Stokes equations.

Margolin, Len G [Los Alamos National Laboratory



Relativistic mirrors for short pulse compression  

NASA Astrophysics Data System (ADS)

Using the quasi-static equations for intense pulse propagation in underdense plasmas, we design semi-transparent relativistic mirrors, driven by short intense lasers. Our aim is to use these mirrors for pulse compression of counter-propagating short pulses. Our analytical results show that the maximum density, and the maximum momentum, of the electrons in the spike in front of an intense short laser pulse scales as 1+a0^2/2, with the optimal value achieved for very short rise times of the laser pulse driver, and independent of the pulse length. We compare our results with 1D and 2D PIC simulations, using OSIRIS. Good agreement is found between the analytical results and the simulations. Furthermore, 2D simulations show that it is possible to generate flat relativistic mirrors with widths on the order of the laser driver spot size. Work partially supported by FCT (Portugal) and DOE and NSF.

Martins, S.; Santos, J.; Fonseca, R. A.; Silva, L. O.; Tsung, F.; Mori, W. B.



Economic and technical feasibility study of compressed air storage  

SciTech Connect

The results of a study of the economic and technical feasibility of compressed air energy storage (CAES) are presented. The study, which concentrated primarily on the application of underground air storage with combustion turbines, consisted of two phases. In the first phase a general assessment of the technical alternatives, economic characteristics and the institutional constraints associated with underground storage of compressed air for utility peaking application was carried out. The goal of this assessment was to identify potential barrier problems and to define the incentive for the implementation of compressed air storage. In the second phase, the general conclusions of the assessment were tested by carrying out the conceptual design of a CAES plant at two specific sites, and a program of further work indicated by the assessment study was formulated. The conceptual design of a CAES plant employing storage in an aquifer and that of a plant employing storage in a conventionally excavated cavern employing a water leg to maintain constant pressure are shown. Recommendations for further work, as well as directions of future turbo-machinery development, are made. It is concluded that compressed air storage is technically feasible for off-peak energy storage, and, depending on site conditions, CAES plants may be favored over simple cycle turbine plants to meet peak demands. (LCL)

Not Available



Reversible compressed domain watermarking by exploiting code space inefficiency  

NASA Astrophysics Data System (ADS)

Algorithms that perform data hiding directly in the compressed domain, without the need for partial decompression or transcoding, are highly desirable. We based this work on the recognition of the idea that only a limited amount of a possible codespace is actually used for any specific code. Therefore, if bits are chosen appropriately, watermarking them will place a codeword outside of the valid codespace. Variable length codes in compressed bitstreams, however, have virtually no redundancy to losslessly carry hidden data. Altered VLCs will likely remain valid. In this work, we examine the bitstream not as individual VLCs but as codeword-pairs. Pairing codewords conceptually shrinks the percentage of available codespace that is actually being used. This idea has a number of key advantages, including that the watermark embedding is mathematically lossless, file size is preserved and the watermarked bitstream will still remain format-compliant. This algorithm is most appropriate for compression algorithms that are error-resilient. For example, the error concealment property of MPEG-4 or H.263+ can also counter bit "errors" caused by the watermarking while playing the video. The off-line portion of the algorithm needs to be run only once for a given VLC table regardless of multiple mediums employing the table. This allows for the algorithm to be applied in real time, both in embedding and removal, due to implementation in the compressed domain.

Mobasseri, Bijan G.; Berger, Robert J., II



Geometric compression through topological surgery  

Microsoft Academic Search

The abundance and importance of complex 3-D data bases in major industry segments, the affordability of interactive 3-D rendering for office and consumer use, and the exploitation of the Internet to distribute and share 3-D data have intensified the need for an effective 3-D geometric compression technique that would significantly reduce the time required to transmit 3-D models over digital

Gabriel Taubin; Jarek Rossignac



Shock compression profiles in ceramics  

Microsoft Academic Search

An investigation of the shock compression properties of high-strength ceramics has been performed using controlled planar impact techniques. In a typical experimental configuration, a ceramic target disc is held stationary, and it is struck by plates of either a similar ceramic or by plates of a well-characterized metal. All tests were performed using either a single-stage propellant gun or a

D. E. Grady; R. L. Moody




Microsoft Academic Search

The active RF pulse compression is considered as a candidate for using in feed systems of future electron-positron colliders.\\u000a The key component of the compressor is an electrically controlled switch changing one state for another in a time much shorter\\u000a than the desired RF pulse width. For an X-band twochannel RF compressor based on TE01-mode energy storage cavities, a gas

A. L. Vikharev; O. A. Ivanov; A. M. Gorbachev; S. V. Kuzikov; V. A. Isaev; V. A. Koldanov; M. A. Lobaev; J. L. Hirshfield; M. A. LaPointe; O. A. Nezhevenko; S. H. Gold; A. K. Kinkead


CMOS wavelet compression imager architecture  

Microsoft Academic Search

The CMOS imager architecture implements ??-modulated Haar wavelet image compression on the focal plane in real time. The active pixel array is integrated with a bank of column-parallel first-order incremental over-sampling analog-to-digital converters (ADCs). Each ADC performs column-wise distributed focal-plane sampling and concurrent signed weighted average quantization, realizing a one-dimensional spatial Haar wavelet transform. A digital delay and adder loop

Ashkan Olyaei; R. Genov



Comparative compressibility of hydrous wadsleyite  

Microsoft Academic Search

Determining the effects of hydration on the density and elastic properties of wadsleyite, beta-Mg2SiO4, is critical to constraining Earth's global geochemical water cycle. Whereas previous studies of the bulk modulus (KT) have studied either hydrous Mg-wadsleyite, or anhydrous Fe-bearing wadsleyite, the combined effects of hydration and iron are under investigation. Also, whereas KT from compressibility studies is relatively well constrained

Y. Chang; S. D. Jacobsen; S. Thomas; C. R. Bina; J. R. Smyth; D. J. Frost; E. H. Hauri; Y. Meng; P. K. Dera



Physics and image data compression  

Microsoft Academic Search

We show how several basic image compression methods (predictive coding, transform coding, and pyramid coding) are based on self-similarity, and a 1\\/f2 power law. Phase transitions often show self-similarity which is characterized by a spectral power law. Natural images often show a self-similarity which is also characterized by a power law spectrum which is near 1\\/f2. Exploring physical analogs leads

Adolph E. Smith; Michael Gormish; Martin Boliek



Compressed air energy storage system  


An internal combustion reciprocating engine is operable as a compressor during slack demand periods utilizing excess power from a power grid to charge air into an air storage reservoir and as an expander during peak demand periods to feed power into the power grid utilizing air obtained from the air storage reservoir together with combustible fuel. Preferably the internal combustion reciprocating engine is operated at high pressure and a low pressure turbine and compressor are also employed for air compression and power generation.

Ahrens, Frederick W. (Naperville, IL); Kartsounes, George T. (Naperville, IL)



LFSRs Do Not Provide Compression  

SciTech Connect

We show that for general input sets linear feedback shift registers (LFSRS) do not provide compression comparable to current, standard algorithms, at least not on the current, standard input files. Rather, LFSRS provide performance on a par with simple, run-length encoding schemes. We exercised three different ways of using LFSRS on the Canterbury, Canterbury Oarge set, the Calgory Corpora, and on three, large graphics files of our own.




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.



Social Work  

Microsoft Academic Search

Unpacking social work's low self-image and even lower social prestige reveals multiple layers of assumptions both within and outside the discipline that coalesce to construct a profession at odds with itself. Social work colludes with social forces which devalue its work while it presents a series of signs that reinforce the negative stereo-types associated with its practices. Social work projects

Gregory D. Gross



Modeling of compressible cake filtration  

SciTech Connect

The transport of suspended solid particles in a liquid through porous media has importance from the viewpoint of engineering practice and industrial applications. Deposition of solid particles on a filter cloth or on a pervious porous medium forms the filter cakes. Following a literature survey, a governing equation for the cake thickness is obtained by considering an instantaneous material balance. In addition to the conservation of mass equations for the liquid, and for suspended and captured solid particles, functional relations among porosity, permeability, and pressure are obtained from literature and solved simultaneously. Later, numerical solutions for cake porosity, pore pressure, cake permeability, velocity of solid particles, concentration of suspended solid particles, and net rate of deposition are obtained. At each instant of time, the porosity decreases throughout the cake from the surface to the filter septum where it has the smallest value. As the cake thickness increases, the trends in pressure variation are similar to data obtained by other researchers. This comparison shows the validity of the theory and the associated solution presented. A sensitivity analysis shows higher pressure values at the filter septum for a less pervious membrane. Finally, a reduction in compressibility parameter provides a thicker cake, causes more particles to be captured inside the cake, and reduces the volumetric filtrate rate. The increase of solid velocity with the reduction in compressibility parameter shows that more rigid cakes compress less.

Abbound, N.M. (Univ. of Connecticut, Waterbury, CT (United States). Dept. of Civil Engineering); Corapcioglu, M.Y. (Texas A and M Univ., College Station, TX (United States). Dept. of Civil Engineering)



Spatial versus spectral compression ratio in compressive sensing of hyperspectral imaging  

NASA Astrophysics Data System (ADS)

Compressive hyperspectral imaging is based on the fact that hyperspectral data is highly redundant. However, there is no symmetry between the compressibility of the spatial and spectral domains, and that should be taken into account for optimal compressive hyperspectral imaging system design. Here we present a study of the influence of the ratio between the compression in the spatial and spectral domains on the performance of a 3D separable compressive hyperspectral imaging method we recently developed.

August, Yitzhak; Vachman, Chaim; Stern, Adrian



Lossless compression of video using temporal information.  


In this paper, we consider the problem of lossless compression of video by taking into account temporal information. Video lossless compression is an interesting possibility in the line of production and contribution. We propose a compression technique which is based on motion compensation, optimal three-dimensional (3-D) linear prediction and context based Golomb-Rice entropy coding. The proposed technique is compared with 3-D extensions of the JPEG-LS standard for still image compression. A compression gain of about 0.8 bit/pel with respect to static JPEG-LS, applied on a frame-by-frame basis, is achievable at a reasonable computational complexity. PMID:18237894

Brunello, Dania; Calvagno, Giancarlo; Mian, Gian Antonio; Rinaldo, Roberto



Mechanical working of metals; theory and practice  

Microsoft Academic Search

This book examines the stress-strain relationships involving the major methods of shaping metals by mechanical working. Includes excellent illustrative matter (photographs and drawings) of processing equipment. Contents: Properties of metals. Deformation of metals under complex stress systems. Survey of mechanical working processes. Forging. Rolling. Extrusion. Indirect compression systems of deformation. Index.



Wavelet compression and segmentation of digital mammograms.  


An initial evaluation of Haar wavelets is presented in this study for the compression of mammographic images. Fifteen mammograms with 105 microns/pixel resolution and varying dynamic range (10 and 12 bits per pixel) containing clustered microcalcifications were compressed with two different rates. The quality and content of the compressed reconstructed images was evaluated by an expert mammographer. The visualization of the cluster was on the average good but degraded with increasing compression because of the discontinuities introduced by these types of wavelets as the compression rate increases. However, the artifacts in the decoded images were seen as totally artificial and were not misinterpreted by the radiologist as calcifications. The classification of the parenchymal densities did not change significantly but the morphology of the calcifications was increasingly distorted as the compression rate increased leading to lower estimates of the suspiciousness of the cluster and higher uncertainties in the diagnosis. The uncompressed and two sets of compressed images were also processed by a wavelet method to extract the calcifications. Despite the fact that the segmentation algorithm generated several false-positive signals in highly compressed images, all true clusters were successfully segmented indicating that the compression process preserved the features of interest. Our preliminary results indicated that wavelets could be used to achieve high compression rates of mammographic images without losing small details such as microcalcification clusters as well as detect the calcifications from either the uncompressed or compressed reconstructed data. Further research and application of multiresolution analysis to digital mammography is continuing. PMID:8172976

Lucier, B J; Kallergi, M; Qian, W; DeVore, R A; Clark, R A; Saff, E B; Clarke, L P



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: 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: 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



Macalester College Problem of the Week  

NSDL National Science Digital Library

The Macalester College Problem of the Week (MacPOW) is a tradition that began in 1968 as a fun, challenging activity for freshmen college students. It continues to this day (hosted by the well known Math Forum site), and about 200 problems are archived on this Web site (out of nearly 1,000 total). All of the unique conundrums are mathematically oriented, and most are word problems that require visualization and critical thinking skills. There is a mailing list to which users can subscribe and receive solutions to each problem at the end of the week. However, because MacPOW is maintained by a professor who regularly uses these problems in class, solutions only remain on the site for the duration of each semester.

Leduc, Rob.; Halverson, Tom.; Wagon, Stan.



Notre Dame community supports Homeless Persons' Week  

Microsoft Academic Search

Hundreds of toiletries, blankets and sleeping bags are heading to some of Western Australia’s neediest residents following an overwhelming response to a collection at Notre Dame’s Fremantle Campus in support of National Homeless Persons’ Week.\\u000aFirst-year Biomedical Science student Alexander Das coordinated the appeal in conjunction with Perth radio station 98.5 Sonshine FM to raise awareness about the unpredictability of

Leigh Dawson



Conceptual design of a packed bed for thermal-energy storage. [In compressed air energy storage system  

Microsoft Academic Search

The design approach, conceptual design, and basic cost estimates for a packed bed for thermal-energy storage in an underground compressed-air-storage system are presented. The conceptual designs considered are a 200-MW(e) system operating on a weekly cycle, and a combined solar-thermal\\/compressed-air-storage system capable of delivering 100 MW(e) to the generator on discharge. Geological stresses in the thermal-energy storage cavity are examined,



Additional geotechnical studies: Strategic Petroleum Reserve (SPR), Weeks Island, Louisiana. [Weeks Island, LA  

SciTech Connect

Previous studies undertaken at the Weeks Island SPR site placed high risk potential on shaft leakage that could lead to shaft failure and ultimately to loss of the crude oil containment. As a result, a geotechnical investigation was undertaken by Sandia National Laboratories (Sandia) and Acres International Corporation (Acres) to define the stratigraphy and hydrologic conditions around the shafts in an attempt to quantify the actual risk potential and define various failure scenarios. In addition, various alternative remedial actions, which could be employed to either eliminate or minimize these risks, were addressed. The investigation program consisted of the drilling of two test borings in proximity to the Service and Production Shafts. These borings confirmed that the stratigraphy overlying the dome in this area consists principally of unconsolidated, well sorted, sandy gravel and sand with permeabilities in the range of 10/sup -2/ to 10/sup -4/ cm/sec. The upper zone of salt was found to be highly friable and fractured with high permeability. The ground water regime over the dome consists of a single aquifer whose water level corresponds with sea level. The salinity of the ground water increases with depth, becoming fully saturated at the top of the salt. Normal recharge of the aquifer is from downward migration of precipitation with radial drainage to the various water courses surrounding the dome. Based on the field and laboratory testing, it is concluded that an uncontrolled leak developing in the shafts could result in rapid flooding of the mine workings, with water flowing from the water courses surrounding the dome. The oil withdrawal system would be inoperable. Subsequent erosion/solutioning of the salt around the oil containment bulkheads could lead to the ultimate loss of oil. 28 figs.

Not Available



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.



Need for recovery from work: evaluating short-term effects of working hours, patterns and schedules  

Microsoft Academic Search

In this paper working hours, patterns and work schedules of employees were evaluated in terms of need for recovery from work. Self-administered questionnaire data from employees of the Maastricht Cohort Study on Fatigue at Work (n = 12,095) were used. Poisson regression analyses and multivariate logistic regression analyses revealed that higher working hours a day and working hours a week

Nicole Jansen; IJmert Kant; Ludovic van Amelsvoort; Frans Nijhuis; Piet van den Brandt



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.



Deformation of plastically compressible hardening-softening-hardening solids  

NASA Astrophysics Data System (ADS)

Motivated by a model of the response of vertically aligned carbon nanotube (VACNT) pillars in uniaxial compression, we consider the deformation of a class of compressible elastic-viscoplastic solids with a hardeningsoftening-hardening variation of flow strength with plastic strain. In previous work (Hutchens et al. 2011) a constitutive relation was presented and used to model the response of VACNT pillars in axisymmetric compression. Subsequently, it was found that due to a programming error the constitutive relation presented in the paper (Hutchens et al. 2011) was not the one actually implemented. In particular, the plastic flow rule actually used did not satisfy plastic normality. Here, we present the constitutive formulation actually implemented in the previous work (Hutchens et al. 2011). Dynamic, finite deformation, finite element calculations are carried out for uniaxial compression, uniaxial tension and for indentation of a "half-space" by a conical indenter tip. A sequential buckling-like deformation mode is found in compression when there is plastic non-normality and hardeningsoftening-hardening. The same material characterization gives rise to a Lüders band-like deformation mode in tension. When there is a deformation mode with a sharp front along mesh boundaries, the overall stress-strain response contains high frequency oscillations that are a mesh artifact. The responses of non-softening solids are also analyzed and their overall stress-strain behavior and deformation modes are compared with those of hardening-softening-hardening solids. We find that indentation with a sharp indenter tip gives a qualitatively equivalent response for hardening and hardening-softening-hardening solids.

Needleman, A.; Hutchens, S. B.; Mohan, N.; Greer, J. R.



Effect of compression stockings on running performance in men runners.  


The purpose of this study was to determine the effect of below-knee compression stockings on running performance in men runners. Using a within-group study design, 21 moderately trained athletes (39.3 +/- 10.9 years) without lower-leg abnormities were randomly assigned to perform a stepwise treadmill test up to a voluntary maximum with and without below-knee compressive stockings. The second treadmill test was completed within 10 days of recovery. Maximum running performance was determined by time under load (minutes), work (kJ), and aerobic capacity ( Velocity (kmxh) and time under load were assessed at different metabolic thresholds using the Dickhuth et al. lactate threshold model. Time under load (36.44 vs. 35.03 minutes, effect size [ES]: 0.40) and total work (422 vs. 399 kJ, ES: 0.30) were significantly higher with compression stockings compared with running socks. However, only slight, nonsignificant differences were observed for VO2max (53.3 vs. 52.2 mlxkgxmin, ES: 0.18). Running performance at the anaerobic (minimum lactate + 1.5 mmolxL) threshold (14.11 vs. 13.90 kmxh, ES: 0.22) and aerobic (minimum lactate + 0.5 mmolxL) thresholds (13.02 vs. 12.74 kmxh, ES: 0.28) was significantly higher using compression stockings. Therefore, stockings with constant compression in the area of the calf muscle significantly improved running performance at different metabolic thresholds. However, the underlying mechanism was only partially explained by a slightly higher aerobic capacity. PMID:19057400

Kemmler, Wolfgang; von Stengel, Simon; Köckritz, Christina; Mayhew, Jerry; Wassermann, Alfred; Zapf, Jürgen



Weekly topotecan in the management of lung cancer  

Microsoft Academic Search

Chemotherapy agents require a range of administration schedules, including 3-weekly, 4-weekly and daily administration. Some agents, for example gemcitabine and vinorelbine, have been developed for use in a weekly regimen. The possibility of administering other agents using a weekly schedule is being investigated. Weekly schedules offer practical benefits in terms of convenience to patients and allow drugs to be combined

Joseph Treat



Solution of Reactive Compressible Flows Using an Adaptive Wavelet Method  

NASA Astrophysics Data System (ADS)

This work presents numerical simulations of reactive compressible flow, including detailed multicomponent transport, using an adaptive wavelet algorithm. The algorithm allows for dynamic grid adaptation which enhances our ability to fully resolve all physically relevant scales. The thermodynamic properties, equation of state, and multicomponent transport properties are provided by CHEMKIN and TRANSPORT libraries. Results for viscous detonation in a H2:O2:Ar mixture, and other problems in multiple dimensions, are included.

Zikoski, Zachary; Paolucci, Samuel; Powers, Joseph



Acoustic streaming in the cochlea under compressive bone conduction excitation  

NASA Astrophysics Data System (ADS)

This work examines the acoustic streaming in the cochlea. A model will be developed to examine the steady flow over a flexible boundary that is induced by compressive excitation of the cochlear capsule. A stokeslet based analysis of oscillatory flows was used to model fluid motion. The influence of evanescent modes on the pressure field is considered as the limit of the aspect ratio epsilon approaches zero. We will show a uniformly valid solution in space.

Aho, Katherine; Sunny, Megha; Nabat, Taoufik; Au, Jenny; Thompson, Charles



Stiffened steel plates under combined compression and bending  

Microsoft Academic Search

This paper presents part of a series of investigations of the behaviour of steel plates stiffened with tee-shape stiffeners and loaded with axial compressive forces with or without bending moments. These elements typically form bridge decks, ship hulls, ship decks and heavy haul equipment walls. Earlier work by the authors validated a non-linear large deformation-finite strain elasto-plastic finite element model

I. A Sheikh; A. E Elwi; G. Y Grondin



Ultrasound attenuation dependence on air compression or expansion processes  

Microsoft Academic Search

In this work variation of ultrasonic attenuation coefficient is analyzed in terms of air compression or expansion processes. In\\u000aclosed spaces changing air volume, the ultrasound attenuation coefficient depends on thermodynamic processes which occur\\u000aduring the air volume change. Two limiting cases are possible: 1) if the change of air volume is very slow or intensive heat\\u000aexchange occurs between

L. Jakevicius; A. Demcenko; R. Mardosaite



Syllabic compression: effective compression ratios for signals modulated at different rates.  


Compression circuits are being used increasingly in hearing aids to reduce the dynamic range of signals. Their performance is usually characterized by: (1) the threshold sound level above which the compression starts to operate; (2) the compression ratio, which is the change in input level (in dB) required to achieve a 1 dB change in output level; and (3) the attack and release times over which the signal is integrated to determine the necessary gain change. In many practical situations, the effective compression ratio obtained with dynamically varying signals such as speech is less than the compression ratio obtained using standard test signals (slow square-wave modulation with large modulation depth). This article describes the effective compression ratios achieved with sinusoidal modulation, as a function of modulation rate, level relative to the compression threshold, compression ratio and time constants. The effects of compression on a typical speech signal are also discussed. PMID:1292819

Stone, M A; Moore, B C



Standardization Work.  

National Technical Information Service (NTIS)

For several years now, the main civil aircraft manufacturers (Airbus and its partners, Boeing, Fokker, McDonnell Douglas) have been working jointly on the writing of technical recommendations and the drawing up of an international standard. This work conc...

O. Malavallon



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



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



Cutaneous vasomotion in patients with chronic venous insufficiency and the influence of compression therapy.  


We investigated in patients with chronic venous insufficiency (CVI) and after compression therapy the fluxmotion within characteristic frequency bands, which were described earlier by Bracic and Stefanovska (Bull. Math. Biol. 60 (1998), 919-935).Therefore, the frequency spectra of laser Doppler flux data of the 36 patient's legs were compared with 41 legs of healthy subjects. In addition, 14 patients with CVI wore a compression stocking (interface pressure: 25-32 mmHg) or compression bandages and were measured after 4 weeks therapy. Data were analyzed by means of a Wavelet packet transformation (a combination of the Daubechies filter of order 4 and the Haar filter).We found significant differences between the patients and the healthy subjects in the frequency intervals of myogenic 0.06-0.16 Hz, respiratory 0.16-0.6 Hz and heart activity 0.6-1.6 Hz (p<0.05, Mann-Whitney U test). Furthermore, the main energy peak height in these frequency intervals increased with the severity of venous disease and was highest in patients with venous leg ulceration. Compression therapy had a significant influence in myogenic vessel activity, which has been proved by a positive frequency shift of 20% (p=0.007, one-sided by the exact Wilcoxon test).In venous disease fluxmotion was increased. Compression therapy over a period of 4 weeks improved myogenic vessel activity. PMID:19136743

Heising, S; Haase, H; Sippel, K; Riedel, F; Jünger, M



Compression behaviour of kappa-carrageenan pellets.  


The compression behavior of high- and low drug strength pellets containing kappa-carrageenan as pelletisation aid was investigated. Model drugs and fillers with different compression mechanisms were used and the effects of compression force and turret speed were examined. Regardless of the compression behavior of their starting components, all pellet formulations exhibited minimal to absent fragmentation and underwent compression by deformation, confirmed by increased equivalent diameter and aspect ratio and decreased roundness factor of the pellets retrieved after de-aggregation of tablets prepared from lubricated pellets. The retrieved pellets showed also higher fracture resistance in three of the tested formulations and no statistically significant difference in the remaining one thus excluding significant crack formation. A densification mechanism was suggested by decreased total porosity and reduced median pore radius of the compressed pellets. No effect of the process parameters on the degree of pellet deformation was reported. The tensile strength of the tablets prepared from unlubricated pellets increased slightly with increased compression force. Compression of pellets with high density silicified microcrystalline cellulose (SMCC HD 90) as embedding powder protected them from severe deformation and resulted in tablets with sufficient tensile strength, minimal friability, negligible elastic recovery and short disintegration time. The percentage of the pellets and the compression force affected the tensile strength of the prepared tablets whereas no influence of the turret speed and the pre-compression force was observed. PMID:20100553

Ghanam, Dima; Hassan, Issa; Kleinebudde, Peter



Static compression of porous dust aggregates  

NASA Astrophysics Data System (ADS)

Context. In protoplanetary disks, dust grains coagulate with each other and grow to form aggregates. While these aggregates are growing by coagulation, their filling factor ? decreases to ? ? 1; however, comets, the remnants of these early planetesimals, have ? ~ 0.1. Thus, static compression of porous dust aggregates is important in planetesimal formation. However, the static compressive strength has only been investigated for relatively high-density aggregates (? > 0.1). Aims: We investigate and find the compressive strength of highly porous aggregates (? ? 1). Methods: We performed three-dimensional N-body simulations of aggregate compression with a particle-particle interaction model. We introduced a new method of static compression: the periodic boundary condition was adopted, and the boundaries move with low speed to get closer. The dust aggregate is compressed uniformly and isotropically by themselves over the periodic boundaries. Results: We empirically derive a formula of the compressive strength of highly porous aggregates (? ? 1). We check the validity of the compressive strength formula for wide ranges of numerical parameters, such as the size of initial aggregates, the boundary speed, the normal damping force, and material. We also compare our results to the previous studies of static compression in the relatively high-density region (? > 0.1) and confirm that our results consistently connect to those in the high-density region. The compressive strength formula is also derived analytically.

Kataoka, A.; Tanaka, H.; Okuzumi, S.; Wada, K.



Establishing perceptual limits for medical image compression  

NASA Astrophysics Data System (ADS)

The acceptance and uptake of the use of lossy compression for medical digital images depends on the reliable determination of limits on the loss of visual information, which would not adversely affect utility of the images for radiologists. A lack of widely accepted thresholds determining acceptable loss for various image modalities and for different compression techniques, motivates a need for further evidence of observer performance in such cases, via comparative studies. This paper contributes results of subjective testing for perceived image quality over three different image modality collections, using test sets of 5 images from each collection compressed by conventional lossy JPEG and by wavelet techniques at 4 different compression quality settings, presented independently to 4 radiologists for viewing. The results indicate a smooth decrease in perceived image quality in all three modalities when the compression quality setting was decreased, which implies there is some intrinsic difficulty in establishing a fixed ideal compression threshold within a modality. Furthermore, substantial differences were observed in the compression quality settings at which perceived absolute image quality was judged to be similar, across the three modalities. The results also indicate that the perceived image quality was usually slightly higher for wavelet compressed images than for JPEG compressed images, at a given compression quality setting.

Maeder, Anthony J.; Deriche, Mohamed



Ruptured rudimentary horn at 22 weeks.  


Rudimentary horn is a developmental anomaly of the uterus. Pregnancy in a non-communicating rudimentary horn is very difficult to diagnose before it ruptures. A case of undiagnosed rudimentary horn pregnancy at 22 weeks presented to Nizwa regional referral hospital in shock with features of acute abdomen. Chances of rupture in first or second trimester are increased with catastrophic haemorrhage leading to increased maternal and perinatal morbidity and mortality. Management of such cases is a challenge till today due to diagnostic dilemma. Expertise in ultrasonography and early resort to surgical management is life saving in such cases. PMID:23293421

Dhar, Hansa



Thanks for Nothing: Entertainment Weekly celebrates Seinfeld  

NSDL National Science Digital Library

Do you find yourself in front of the television on Thursday nights watching four of the most selfish and petty people in the world? And, well, loving it? Then this Seinfeld site is for you. Produced by Entertainment Weekly, it chronicles all the particulars of their codependence as well as trivia tidbits (e.g., the 1989 pilot episode was deemed "weak," and Elaine's home town is Towson, MD). Learn lessons like "No good ever comes from helping one's fellow man" or simply peruse all eight seasons' episodes, which are critiqued and graded for your viewing pleasure.


Earth Science Week is coming soon  

NASA Astrophysics Data System (ADS)

AGU along with other societies, federal agencies, and organizations is participating in Earth Science Week (ESW), being held 14-20 October 2012 ( This year's theme, “Discovering careers in the Earth sciences,” encourages young people everywhere to explore the natural world and learn about the geosciences. To find out more about how you can participate in ESW by planning an event, go to To learn about ESW events taking place in your area, visit

Asher, Pranoti M.



Improved satellite image compression and reconstruction via genetic algorithms  

NASA Astrophysics Data System (ADS)

A wide variety of signal and image processing applications, including the US Federal Bureau of Investigation's fingerprint compression standard [3] and the JPEG-2000 image compression standard [26], utilize wavelets. This paper describes new research that demonstrates how a genetic algorithm (GA) may be used to evolve transforms that outperform wavelets for satellite image compression and reconstruction under conditions subject to quantization error. The new approach builds upon prior work by simultaneously evolving real-valued coefficients representing matched forward and inverse transform pairs at each of three levels of a multi-resolution analysis (MRA) transform. The training data for this investigation consists of actual satellite photographs of strategic urban areas. Test results show that a dramatic reduction in the error present in reconstructed satellite images may be achieved without sacrificing the compression capabilities of the forward transform. The transforms evolved during this research outperform previous start-of-the-art solutions, which optimized coefficients for the reconstruction transform only. These transforms also outperform wavelets, reducing error by more than 0.76 dB at a quantization level of 64. In addition, transforms trained using representative satellite images do not perform quite as well when subsequently tested against images from other classes (such as fingerprints or portraits). This result suggests that the GA developed for this research is automatically learning to exploit specific attributes common to the class of images represented in the training population.

Babb, Brendan; Moore, Frank; Peterson, Michael; Lamont, Gary



Adiabatic Compression of Compact Tori for Current Drive and Heating  

NASA Astrophysics Data System (ADS)

Several critical issues stand in the development path for compact tori. An important one is the production of strong magnetic fields, (or large flux amplifications) by use of a low current source. The Pulsed Build-up Experiment is a Phase II SBIR project in which we aim to show a new means for generating strong magnetic fields from a low current source, namely, the repetitive injection of helicity-bearing plasma that also undergoes an acceleration and compression. In the Phase I SBIR, advanced computations were benchmarked against analytic theory and run to determine the best means for the acceleration and compression of a compact torus plasma. The study included detailed simulations of magnetic reconnection. In Phase II, an experiment has been designed and is being built to produce strong magnetic fields in a spheromak by the repetitive injection of magnetic helicity from a low current coaxial plasma source. The plasma will be accelerated and compressed in a similar manner to a traveling wave adiabatic compression scheme that was previously applied to a mirror plasma [1]. [1] P. M. Bellan Scalings for a Traveling Mirror Adiabatic Magnetic Compressor Rev. Sci. Instrum. 53(8) 1214 (1982) Work supported by DOE Grant No. DE-FG02-06ER84449.

Woodruff, Simon; McNab, Angus; Miller, Kenneth; Ziemba, Tim



Influence of 6-week, 6 days per week, training on pituitary function in recreational athletes.  

PubMed Central

The influence on pituitary function of 6 weeks of training on 6 days a week was examined in six recreational athletes. Endurance training on a bicycle ergometer for 31-33 min was performed on 4 days each week at 90-96% (weeks 1-3) and 89-92% (weeks 4-6) of the 4 mmol lactate thresholds determined on day 0 and day 21, respectively, with interval training of 3-5 x 3-5 min in addition on 2 days a week at 117-127% and 115-110%, respectively. Determination of the serum hormone levels and a combined pituitary function test (200 micrograms thyrotropin releasing hormone (TRH), 100 micrograms gonadotrophin-releasing hormone (GnRH), 100 micrograms corticotrophin releasing hormone (CRH), 50 micrograms growth hormone releasing hormone (GHRH)) were made before training, after 6 weeks of training and after another 3 weeks of recovery. Training increased performance at 2 mmol lactate by 25%, at 4 mmol by 12%, and maximum performance by approximately 12%. The releasing hormone-stimulable prolactin, thyroid stimulating hormone (TSH) and somatotrophic hormone (STH) synthesis-secretion capacity remained unchanged, the adrenocorticotrophic hormone (ACTH) was increased after training. Cortisol release was reduced, follicle-stimulating hormone (FSH)-synthesis-secretion capacity was increased after training, and the luteinizing hormone (LH)-synthesis-secretion capacity reduced. This had no influence on base or exercise-induced serum hormone levels (cortisol, aldosterone, insulin, prolactin, FSH, LH, TSH, ACTH, ADH and STH), which showed no dependence on training, except for free testosterone which showed a decreasing trend (P < 0.10) of 19-25% and post-exercise ACTH which showed an increasing trend of 33% (P < 0.10). Conditioning (cortisol sensitivity and ACTH response) or adaptation (FSH and LH responses) to changed testosterone serum levels and altered spermatogenesis is discussed.

Lehmann, M; Knizia, K; Gastmann, U; Petersen, K G; Khalaf, A N; Bauer, S; Kerp, L; Keul, J



Efficient compression of quantum information  

SciTech Connect

We propose a scheme for an exact efficient transformation of a tensor product state of many identically prepared qubits into a state of a logarithmically small number of qubits. Using a quadratic number of elementary quantum gates we transform N identically prepared qubits into a state, which is nontrivial only on the first [log{sub 2}(N+1)] qubits. This procedure might be useful for quantum memories, as only a small portion of the original qubits has to be stored. Another possible application is in communicating a direction encoded in a set of quantum states, as the compressed state provides a high-effective method for such an encoding.

Plesch, Martin [Institute of Physics, Slovak Academy of Sciences, 845 11 Bratislava (Slovakia); Faculty of Physics, University of Vienna, Vienna (Austria); Buzek, Vladimir [Institute of Physics, Slovak Academy of Sciences, 845 11 Bratislava (Slovakia)



Statistical mechanics of compressed sensing.  


Compressed sensing (CS) is an important recent advance that shows how to reconstruct sparse high dimensional signals from surprisingly small numbers of random measurements. The nonlinear nature of the reconstruction process poses a challenge to understanding the performance of CS. We employ techniques from the statistical physics of disordered systems to compute the typical behavior of CS as a function of the signal sparsity and measurement density. We find surprising and useful regularities in the nature of errors made by CS, a new phase transition which reveals the possibility of CS for nonnegative signals without optimization, and a new null model for sparse regression. PMID:20482215

Ganguli, Surya; Sompolinsky, Haim



Faster STORM Using Compressed Sensing  

PubMed Central

In super-resolution microscopy methods based on single-molecule switching, the rate to accumulate single-molecule activation events often limits the time resolution. Here, we developed a sparse-signal recovery technique using compressed sensing to analyze images with highly overlapping fluorescent spots. This method allows an activated fluorophore density an order of magnitude higher than what conventional single-molecule fitting methods can handle. Using this method, we have demonstrated imaging microtubule dynamics in living cells with a time resolution of 3 s.

Zhu, Lei; Zhang, Wei; Elnatan, Daniel; Huang, Bo



Unconfined compression of white matter.  


The porous properties of brain tissue are important for understanding normal and abnormal cerebrospinal fluid flow in the brain. In this study, a poroviscoelastic model was fitted to the stress relaxation response of white matter in unconfined compression performed under a range of low strain rates. A set of experiments was also performed on the tissue samples using a no-slip boundary condition. Results from these experiments demonstrated that the rheological response of the white matter is primarily governed by the intrinsic viscoelastic properties of the solid phase. The permeability of white matter was found to be of the order of 10(-12) m4/Ns. PMID:16376349

Cheng, Shaokoon; Bilston, Lynne E



Work–life strategies in the Australian construction industry: Implementation issues in a dynamic project-based work environment  

Microsoft Academic Search

A participatory work–life balance intervention was implemented in a medium-sized construction contracting organization based in Melbourne, Australia. Weekly data capturing the number of hours worked, satisfaction with work–life balance and capacity to complete required tasks at work and at home were collected for 25 consecutive weeks. Data was subjected to time series modeling procedures and weekly work hours were found

Helen Lingard; Valerie Francis; Michelle Turner


The compression\\/absorption heat pump cycle—conceptual design improvements and comparisons with the compression cycle  

Microsoft Academic Search

Performance improvement of an industrial single-stage compression\\/absorption heat pump (CAHP) using an ammonia\\/water mixture as the working fluid has been studied theoretically. By allowing a higher absorber pressure (40 bar) than the highest design pressure of today's screw compressors (25 bar), higher COPs could be obtained. Longer falling-film tubes in the vertical shell-and-tube absorber and desorber also increased the COP.

Magnus Hultén; Thore Berntsson



76 FR 60351 - Minority Enterprise Development Week, 2011  

Federal Register 2010, 2011, 2012, 2013

...8721--Minority Enterprise Development Week, 2011 Proclamation 8722--Gold Star...2011 Minority Enterprise Development Week, 2011 By the President of the United States...During Minority Enterprise Development Week, we honor minority enterprises as...



76 FR 29131 - Emergency Medical Services Week, 2011  

Federal Register 2010, 2011, 2012, 2013

...Proclamation 8674--Emergency Medical Services Week, 2011 Proclamation 8675--National Defense...Transportation Day and National Transportation Week, 2011 Proclamation 8676--Peace Officers Memorial Day and Police Week, 2011 Proclamation 8677--World...