U.S. Army physical demands study: Prevalence and frequency of performing physically demanding tasks in deployed and non-deployed settings.

PubMed

Boye, Michael W; Cohen, Bruce S; Sharp, Marilyn A; Canino, Maria C; Foulis, Stephen A; Larcom, Kathleen; Smith, Laurel

2017-11-01

To compare percentages of on-duty time spent performing physically demanding soldier tasks in non-deployed and deployed settings, and secondarily examine the number of physically demanding tasks performed among five Army combat arms occupational specialties. Job task analysis. Soldiers (n=1295; over 99% serving on active duty) across five Army jobs completed one of three questionnaires developed using reviews of job and task related documents, input from subject matter experts, observation of task performance, and conduct of focus groups. Soldiers reported estimates of the total on-duty time spent performing physically demanding tasks in both deployed and non-deployed settings. One-way analyses of variance and Duncan post-hoc tests were used to compare percentage time differences by job. Two-tailed t-tests were used to evaluate differences by setting. Frequency analyses were used to present supplementary findings. Soldiers reported performing physically demanding job-specific tasks 17.7% of the time while non-deployed and 19.6% of the time while deployed. There were significant differences in time spent on job-specific tasks across settings (p<0.05) for three of five occupational specialties. When categories of physically demanding tasks were grouped, all soldiers reported spending more time on physically demanding tasks when deployed (p<0.001). Twenty-five percent reported performing less than half the physically demanding tasks represented on the questionnaire in the last two years. Soldiers spent more time performing physically demanding tasks while deployed compared to non-deployed but spent similar amounts of time performing job-specific tasks. Published by Elsevier Ltd.

Association of sleep and academic performance.

PubMed

Eliasson, Arne; Eliasson, Anders; King, Joseph; Gould, Ben; Eliasson, Arn

2002-03-01

Poor school performance by adolescent students has been attributed in part to insufficient sleep. It is recognized that a number of factors lead to diminished total sleep time and chief among these are early school start times and sleep phase delay in adolescence. Political initiatives are gaining momentum across the United States to require later school start times with the intent of increasing total sleep time and consequently improving school performance. Later school start times come with significant costs and impact other activities of families and communities. The decision to implement later school start times cannot be made lightly and deserves support of well-performed research on the impact of these changes. A study evaluating the association of academic performance and total sleep time was performed in middle school and high school students in a suburban Maryland school system. Preliminary results of this study show no correlation of total sleep time with academic performance. Before mandating costly changes in school schedules, it would be useful to perform further research to determine the effects of increasing sleep time on the behaviors of adolescent students.

14 CFR 234.4 - Reporting of on-time performance.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Reporting of on-time performance. 234.4 Section 234.4 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS AIRLINE SERVICE QUALITY PERFORMANCE REPORTS § 234.4 Reporting of on-time...

RTSJ Memory Areas and Their Affects on the Performance of a Flight-Like Attitude Control System

NASA Technical Reports Server (NTRS)

Niessner, Albert F.; Benowitz, Edward G.

2003-01-01

The two most important factors in improving performance in any software system, but especially a real-time, embedded system, are knowing which components are the low performers and knowing what can be done to improve their performance. The word performance with respect to a real-time, embedded system does not necessarily mean fast execution, which is the common definition when discussing non real-time systems. It also includes meeting all of the specified execution dead-lines and executing at the correct time without sacrificing non real-time performance. Using a Java prototype of an existing control system used on Deep Space 1[1], the effects from adding memory areas are measured and evaluated with respect to improving performance.

Effect of time delay on surgical performance during telesurgical manipulation.

PubMed

Fabrizio, M D; Lee, B R; Chan, D Y; Stoianovici, D; Jarrett, T W; Yang, C; Kavoussi, L R

2000-03-01

Telementoring allows a less experienced surgeon to benefit from an expert surgical consultation, reducing cost, travel, and the learning curve associated with new procedures. However, there are several technical limitations that affect practical applications. One potentially serious problem is the time delay that occurs any time data are transferred across long distances. To date, the effect of time delay on surgical performance has not been studied. A two-phase trial was designed to examine the effect of time delay on surgical performance. In the first phase, a series of tasks was performed, and the numbers of robotic movements required for completion was counted. Programmed incremental time delays were made in audiovisual acquisition and robotic controls. The number of errors made while performing each task at various time delay intervals was noted. In the second phase, a remote surgeon in Baltimore performed the tasks 9000 miles away in Singapore. The number of errors made was recorded. As the time delay increased, the number of operator errors increased. The accuracy needed to perform remote robotic procedures was diminished as the time delay increased. A learning curve did exist for each task, but as the time delay interval increased, it took longer to complete the task. Time delay does affect surgical performance. There is an acceptable delay of <700 msec in which surgeons can compensate for this phenomenon. Clinical studies will be needed to evaluate the true impact of time delay.

Influence of 2D and 3D view on performance and time estimation in minimal invasive surgery.

PubMed

Blavier, A; Nyssen, A S

2009-11-01

This study aimed to evaluate the impact of two-dimensional (2D) and three-dimensional (3D) images on time performance and time estimation during a surgical motor task. A total of 60 subjects without any surgical experience (nurses) and 20 expert surgeons performed a fine surgical task with a new laparoscopic technology (da Vinci robotic system). The 80 subjects were divided into two groups, one using 3D view option and the other using 2D view option. We measured time performance and asked subjects to verbally estimate their time performance. Our results showed faster performance in 3D than in 2D view for novice subjects while the performance in 2D and 3D was similar in the expert group. We obtained a significant interaction between time performance and time evaluation: in 2D condition, all subjects accurately estimated their time performance while they overestimated it in the 3D condition. Our results emphasise the role of 3D in improving performance and the contradictory feeling about time evaluation in 2D and 3D. This finding is discussed in regard with the retrospective paradigm and suggests that 2D and 3D images are differently processed and memorised.

75 FR 21716 - Agency Information Collection; Activity Under OMB Review; Airline Service Quality Performance...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-26

... large certificated air carriers to file ``On-Time Flight Performance Reports'' and ``Mishandled-Baggage... On-Time Flight Performance Reports to identify problem areas within the air traffic control system... concerning their chances of on-time flights and the rate of mishandled baggage by the 18 largest scheduled...

Effects of Math Anxiety and Perfectionism on Timed versus Untimed Math Testing in Mathematically Gifted Sixth Graders

PubMed Central

Tsui, Joanne M.; Mazzocco, Michèle M. M.

2009-01-01

This study was designed to examine the effects of math anxiety and perfectionism on math performance, under timed testing conditions, among mathematically gifted sixth graders. We found that participants had worse math performance during timed versus untimed testing, but this difference was statistically significant only when the timed condition preceded the untimed condition. We also found that children with higher levels of either math anxiety or perfectionism had a smaller performance discrepancy during timed versus untimed testing, relative to children with lower levels of math anxiety or perfectionism. There were no statistically significant gender differences in overall test performance, nor in levels of math anxiety or perfectionism; however, the difference between performance on timed and untimed math testing was statistically significant for girls, but not for boys. Implications for educators are discussed. PMID:20084180

Sleep Deprivation and Time-on-Task Performance Decrement in the Rat Psychomotor Vigilance Task

PubMed Central

Oonk, Marcella; Davis, Christopher J.; Krueger, James M.; Wisor, Jonathan P.; Van Dongen, Hans P.A.

2015-01-01

Study Objectives: The rat psychomotor vigilance task (rPVT) was developed as a rodent analog of the human psychomotor vigilance task (hPVT). We examined whether rPVT performance displays time-on-task effects similar to those observed on the hPVT. Design: The rPVT requires rats to respond to a randomly presented light stimulus to obtain a water reward. Rats were water deprived for 22 h prior to each 30-min rPVT session to motivate performance. We analyzed rPVT performance over time on task and as a function of the response-stimulus interval, at baseline and after sleep deprivation. Setting: The study was conducted in an academic research vivarium. Participants: Male Long-Evans rats were trained to respond to a 0.5 sec stimulus light within 3 sec of stimulus onset. Complete data were available for n = 20 rats. Interventions: Rats performed the rPVT for 30 min at baseline and after 24 h total sleep deprivation by gentle handling. Measurements and Results: Compared to baseline, sleep deprived rats displayed increased performance lapses and premature responses, similar to hPVT lapses of attention and false starts. However, in contrast to hPVT performance, the time-on-task performance decrement was not significantly enhanced by sleep deprivation. Moreover, following sleep deprivation, rPVT response times were not consistently increased after short response-stimulus intervals. Conclusions: The rat psychomotor vigilance task manifests similarities to the human psychomotor vigilance task in global performance outcomes, but not in post-sleep deprivation effects of time on task and response-stimulus interval. Citation: Oonk M, Davis CJ, Krueger JM, Wisor JP, Van Dongen HPA. Sleep deprivation and time-on-task performance decrement in the rat psychomotor vigilance task. SLEEP 2015;38(3):445–451. PMID:25515099

Effect of feedback mode and task difficulty on quality of timing decisions in a zero-sum game.

PubMed

Tikuisis, Peter; Vartanian, Oshin; Mandel, David R

2014-09-01

The objective was to investigate the interaction between the mode of performance outcome feedback and task difficulty on timing decisions (i.e., when to act). Feedback is widely acknowledged to affect task performance. However, the extent to which feedback display mode and its impact on timing decisions is moderated by task difficulty remains largely unknown. Participants repeatedly engaged a zero-sum game involving silent duels with a computerized opponent and were given visual performance feedback after each engagement. They were sequentially tested on three different levels of task difficulty (low, intermediate, and high) in counterbalanced order. Half received relatively simple "inside view" binary outcome feedback, and the other half received complex "outside view" hit rate probability feedback. The key dependent variables were response time (i.e., time taken to make a decision) and survival outcome. When task difficulty was low to moderate, participants were more likely to learn and perform better from hit rate probability feedback than binary outcome feedback. However, better performance with hit rate feedback exacted a higher cognitive cost manifested by higher decision response time. The beneficial effect of hit rate probability feedback on timing decisions is partially moderated by task difficulty. Performance feedback mode should be judiciously chosen in relation to task difficulty for optimal performance in tasks involving timing decisions.

PPC750 Performance Monitor

NASA Technical Reports Server (NTRS)

Meyer, Donald; Uchenik, Igor

2007-01-01

The PPC750 Performance Monitor (Perfmon) is a computer program that helps the user to assess the performance characteristics of application programs running under the Wind River VxWorks real-time operating system on a PPC750 computer. Perfmon generates a user-friendly interface and collects performance data by use of performance registers provided by the PPC750 architecture. It processes and presents run-time statistics on a per-task basis over a repeating time interval (typically, several seconds or minutes) specified by the user. When the Perfmon software module is loaded with the user s software modules, it is available for use through Perfmon commands, without any modification of the user s code and at negligible performance penalty. Per-task run-time performance data made available by Perfmon include percentage time, number of instructions executed per unit time, dispatch ratio, stack high water mark, and level-1 instruction and data cache miss rates. The performance data are written to a file specified by the user or to the serial port of the computer

Effects of System Timing Parameters on Operator Performance in a Personnel Records Task

DTIC Science & Technology

1981-03-01

work sampling, embedded performance measures, and operator satisfaction ratings) are needed to provide a complete analysis of the effects of the four...HFL-8 l-l/NPRDC-8 1-1 March 1981 EFFECTS OF SYSTEM TIMING PARAMETERS ON OPERATOR PERFORMANCE IN A PERSONNEL RECORDS TASK Robert C. Williges Beverly H...and Subtitle) S. TYPE OF REPORT & PERIOD COVERED EFFECTS OF SYSTEM TIMING PARAMETERS ON OPERATOR PERFORMANCE IN A PERSONNEL RECORDS TASK Final

An easy game for frauds? Effects of professional experience and time pressure on passport-matching performance.

PubMed

Wirth, Benedikt Emanuel; Carbon, Claus-Christian

2017-06-01

Despite extensive research on unfamiliar face matching, little is known about factors that might affect matching performance in real-life scenarios. We conducted 2 experiments to investigate the effects of several such factors on unfamiliar face-matching performance in a passport-check scenario. In Experiment 1, we assessed the effect of professional experience on passport-matching performance. The matching performance of 96 German Federal Police officers working at Munich Airport was compared with that of 48 novices without specific face-matching experience. Police officers significantly outperformed novices, but nevertheless missed a high ratio of frauds. Moreover, the effects of manipulating specific facial features (with paraphernalia like glasses and jewelry, distinctive features like moles and scars, and hairstyle) and of variations in the physical distance between the faces being matched were investigated. Whereas manipulation of physical distance did not have a significant effect, manipulations of facial features impaired matching performance. In Experiment 2, passport-matching performance was assessed in relation to time constraints. Novices matched passports either without time constraints, or under a local time limit (which is typically used in laboratory studies), or under a global time limit (which usually occurs during real-life border controls). Time pressure (especially the global time limit) significantly impaired matching performance. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The Power of "We": Effects of Psychological Collectivism on Team Performance over Time

ERIC Educational Resources Information Center

Dierdorff, Erich C.; Bell, Suzanne T.; Belohlav, James A.

2011-01-01

We examined the influences of different facets of psychological collectivism (Preference, Reliance, Concern, Norm Acceptance, and Goal Priority) on team functioning at 3 different performance depictions: initial team performance, end-state team performance, and team performance change over time. We also tested the extent to which team-member…

Performance bounds on parallel self-initiating discrete-event

NASA Technical Reports Server (NTRS)

Nicol, David M.

1990-01-01

The use is considered of massively parallel architectures to execute discrete-event simulations of what is termed self-initiating models. A logical process in a self-initiating model schedules its own state re-evaluation times, independently of any other logical process, and sends its new state to other logical processes following the re-evaluation. The interest is in the effects of that communication on synchronization. The performance is considered of various synchronization protocols by deriving upper and lower bounds on optimal performance, upper bounds on Time Warp's performance, and lower bounds on the performance of a new conservative protocol. The analysis of Time Warp includes the overhead costs of state-saving and rollback. The analysis points out sufficient conditions for the conservative protocol to outperform Time Warp. The analysis also quantifies the sensitivity of performance to message fan-out, lookahead ability, and the probability distributions underlying the simulation.

[Influence of personality traits on reaction performance in volunteers after a single administration of placebo, crotylbarbital and caffeine].

PubMed

Meyer, F P; Walther, T; Walther, H

1983-01-01

We examined the influence of single applications of placebo, caffeine (7 mg/kg), and crotylbarbital (2 mg/kg) on reaction and attention performance in 15 volunteers. A newly developed reaction-time apparatus permits the reaction time to be split for differentiation between initiation time and movement time. Moreover, simple and complex attention performance can be quantified. The volunteers were selected as to the dimensions of "introversion/extraversion" and "emotional lability/stability" by means of the Freiburg Personality Inventory. Labile volunteers responded to placebo faster than stables. Caffeine improved mainly the performance of introverted subjects. Crotylbarbital was without influence on the reaction time at the threshold dose applied.

Multiple Off-Ice Performance Variables Predict On-Ice Skating Performance in Male and Female Division III Ice Hockey Players.

PubMed

Janot, Jeffrey M; Beltz, Nicholas M; Dalleck, Lance D

2015-09-01

The purpose of this study was to determine if off-ice performance variables could predict on-ice skating performance in Division III collegiate hockey players. Both men (n = 15) and women (n = 11) hockey players (age = 20.5 ± 1.4 years) participated in the study. The skating tests were agility cornering S-turn, 6.10 m acceleration, 44.80 m speed, modified repeat skate, and 15.20 m full speed. Off-ice variables assessed were years of playing experience, height, weight and percent body fat and off-ice performance variables included vertical jump (VJ), 40-yd dash (36.58m), 1-RM squat, pro-agility, Wingate peak power and peak power percentage drop (% drop), and 1.5 mile (2.4km) run. Results indicated that 40-yd dash (36.58m), VJ, 1.5 mile (2.4km) run, and % drop were significant predictors of skating performance for repeat skate (slowest, fastest, and average time) and 44.80 m speed time, respectively. Four predictive equations were derived from multiple regression analyses: 1) slowest repeat skate time = 2.362 + (1.68 x 40-yd dash time) + (0.005 x 1.5 mile run), 2) fastest repeat skate time = 9.762 - (0.089 x VJ) - (0.998 x 40-yd dash time), 3) average repeat skate time = 7.770 + (1.041 x 40-yd dash time) - (0.63 x VJ) + (0.003 x 1.5 mile time), and 4) 47.85 m speed test = 7.707 - (0.050 x VJ) - (0.01 x % drop). It was concluded that selected off-ice tests could be used to predict on-ice performance regarding speed and recovery ability in Division III male and female hockey players. Key pointsThe 40-yd dash (36.58m) and vertical jump tests are significant predictors of on-ice skating performance specific to speed.In addition to 40-yd dash and vertical jump, the 1.5 mile (2.4km) run for time and percent power drop from the Wingate anaerobic power test were also significant predictors of skating performance that incorporates the aspect of recovery from skating activity.Due to the specificity of selected off-ice variables as predictors of on-ice performance, coaches can elect to assess player performance off-ice and focus on other uses of valuable ice time for their individual teams.

Overall ED efficiency is associated with decreased time to percutaneous coronary intervention for ST-segment elevation myocardial infarction.

PubMed

Jones, Christopher W; Sonnad, Seema S; Augustine, James J; Reese, Charles L

2014-10-01

Performance of percutaneous coronary intervention (PCI) within 90 minutes of hospital arrival for ST-segment elevation myocardial infarction patients is a commonly cited clinical quality measure. The Centers for Medicare and Medicaid Services use this measure to adjust hospital reimbursement via the Value-Based Purchasing Program. This study investigated the relationship between hospital performance on this quality measure and emergency department (ED) operational efficiency. Hospital-level data from Centers for Medicare and Medicaid Services on PCI quality measure performance was linked to information on operational performance from 272 US EDs obtained from the Emergency Department Benchmarking Alliance annual operations survey. Standard metrics of ED size, acuity, and efficiency were compared across hospitals grouped by performance on the door-to-balloon time quality measure. Mean hospital performance on the 90-minute arrival to PCI measure was 94.0% (range, 42-100). Among hospitals failing to achieve the door-to-balloon time performance standard, median ED length of stay was 209 minutes, compared with 173 minutes among those hospitals meeting the benchmark standard (P < .001). Similarly, median time from ED patient arrival to physician evaluation was 39 minutes for hospitals below the performance standard and 23 minutes for hospitals at the benchmark standard (P < .001). Markers of ED size and acuity, including annual patient volume, admission rate, and the percentage of patients arriving via ambulance did not vary with door-to-balloon time. Better performance on measures associated with ED efficiency is associated with more timely PCI performance. Copyright © 2014 Elsevier Inc. All rights reserved.

Impact of temporal resolution of inputs on hydrological model performance: An analysis based on 2400 flood events

NASA Astrophysics Data System (ADS)

Ficchì, Andrea; Perrin, Charles; Andréassian, Vazken

2016-07-01

Hydro-climatic data at short time steps are considered essential to model the rainfall-runoff relationship, especially for short-duration hydrological events, typically flash floods. Also, using fine time step information may be beneficial when using or analysing model outputs at larger aggregated time scales. However, the actual gain in prediction efficiency using short time-step data is not well understood or quantified. In this paper, we investigate the extent to which the performance of hydrological modelling is improved by short time-step data, using a large set of 240 French catchments, for which 2400 flood events were selected. Six-minute rain gauge data were available and the GR4 rainfall-runoff model was run with precipitation inputs at eight different time steps ranging from 6 min to 1 day. Then model outputs were aggregated at seven different reference time scales ranging from sub-hourly to daily for a comparative evaluation of simulations at different target time steps. Three classes of model performance behaviour were found for the 240 test catchments: (i) significant improvement of performance with shorter time steps; (ii) performance insensitivity to the modelling time step; (iii) performance degradation as the time step becomes shorter. The differences between these groups were analysed based on a number of catchment and event characteristics. A statistical test highlighted the most influential explanatory variables for model performance evolution at different time steps, including flow auto-correlation, flood and storm duration, flood hydrograph peakedness, rainfall-runoff lag time and precipitation temporal variability.

Apollo 15 time and motion study

NASA Technical Reports Server (NTRS)

Kubis, J. F.; Elrod, J. T.; Rusnak, R.; Barnes, J. E.

1972-01-01

A time and motion study of Apollo 15 lunar surface activity led to examination of four distinct areas of crewmen activity. These areas are: an analysis of lunar mobility, a comparative analysis of tasks performed in 1-g training and lunar EVA, an analysis of the metabolic cost of two activities that are performed in several EVAs, and a fall/near-fall analysis. An analysis of mobility showed that the crewmen used three basic mobility patterns (modified walk, hop, side step) while on the lunar surface. These mobility patterns were utilized as adaptive modes to compensate for the uneven terrain and varied soil conditions that the crewmen encountered. A comparison of the time required to perform tasks at the final 1-g lunar EVA training sessions and the time required to perform the same task on the lunar surface indicates that, in almost all cases, it took significantly more time (on the order of 40%) to perform tasks on the moon. This increased time was observed even after extraneous factors (e.g., hardware difficulties) were factored out.

Assimilation Time as a Factor of Performance: Impact on a New Generation of Students

ERIC Educational Resources Information Center

Mohrweis, Lawrence C.; Pitt, Kay C.

2010-01-01

This paper explores the issue of whether assimilation time has any bearing on the performance of students. Assimilation time is defined as the number of times during the week that a class meets. This study examined whether students would perform better in a 50-minute class that met three days a week versus a 75-minute class that met just two days…

Run-time parallelization and scheduling of loops

NASA Technical Reports Server (NTRS)

Saltz, Joel H.; Mirchandaney, Ravi; Crowley, Kay

1991-01-01

Run-time methods are studied to automatically parallelize and schedule iterations of a do loop in certain cases where compile-time information is inadequate. The methods presented involve execution time preprocessing of the loop. At compile-time, these methods set up the framework for performing a loop dependency analysis. At run-time, wavefronts of concurrently executable loop iterations are identified. Using this wavefront information, loop iterations are reordered for increased parallelism. Symbolic transformation rules are used to produce: inspector procedures that perform execution time preprocessing, and executors or transformed versions of source code loop structures. These transformed loop structures carry out the calculations planned in the inspector procedures. Performance results are presented from experiments conducted on the Encore Multimax. These results illustrate that run-time reordering of loop indexes can have a significant impact on performance.

The Vigilance Decrement in Executive Function Is Attenuated When Individual Chronotypes Perform at Their Optimal Time of Day

PubMed Central

Lara, Tania; Madrid, Juan Antonio; Correa, Ángel

2014-01-01

Time of day modulates our cognitive functions, especially those related to executive control, such as the ability to inhibit inappropriate responses. However, the impact of individual differences in time of day preferences (i.e. morning vs. evening chronotype) had not been considered by most studies. It was also unclear whether the vigilance decrement (impaired performance with time on task) depends on both time of day and chronotype. In this study, morning-type and evening-type participants performed a task measuring vigilance and response inhibition (the Sustained Attention to Response Task, SART) in morning and evening sessions. The results showed that the vigilance decrement in inhibitory performance was accentuated at non-optimal as compared to optimal times of day. In the morning-type group, inhibition performance decreased linearly with time on task only in the evening session, whereas in the morning session it remained more accurate and stable over time. In contrast, inhibition performance in the evening-type group showed a linear vigilance decrement in the morning session, whereas in the evening session the vigilance decrement was attenuated, following a quadratic trend. Our findings imply that the negative effects of time on task in executive control can be prevented by scheduling cognitive tasks at the optimal time of day according to specific circadian profiles of individuals. Therefore, time of day and chronotype influences should be considered in research and clinical studies as well as real-word situations demanding executive control for response inhibition. PMID:24586404

Measures of rowing performance.

PubMed

Smith, T Brett; Hopkins, Will G

2012-04-01

Accurate measures of performance are important for assessing competitive athletes in practi~al and research settings. We present here a review of rowing performance measures, focusing on the errors in these measures and the implications for testing rowers. The yardstick for assessing error in a performance measure is the random variation (typical or standard error of measurement) in an elite athlete's competitive performance from race to race: ∼1.0% for time in 2000 m rowing events. There has been little research interest in on-water time trials for assessing rowing performance, owing to logistic difficulties and environmental perturbations in performance time with such tests. Mobile ergometry via instrumented oars or rowlocks should reduce these problems, but the associated errors have not yet been reported. Measurement of boat speed to monitor on-water training performance is common; one device based on global positioning system (GPS) technology contributes negligible extra random error (0.2%) in speed measured over 2000 m, but extra error is substantial (1-10%) with other GPS devices or with an impeller, especially over shorter distances. The problems with on-water testing have led to widespread use of the Concept II rowing ergometer. The standard error of the estimate of on-water 2000 m time predicted by 2000 m ergometer performance was 2.6% and 7.2% in two studies, reflecting different effects of skill, body mass and environment in on-water versus ergometer performance. However, well trained rowers have a typical error in performance time of only ∼0.5% between repeated 2000 m time trials on this ergometer, so such trials are suitable for tracking changes in physiological performance and factors affecting it. Many researchers have used the 2000 m ergometer performance time as a criterion to identify other predictors of rowing performance. Standard errors of the estimate vary widely between studies even for the same predictor, but the lowest errors (~1-2%) have been observed for peak power output in an incremental test, some measures of lactate threshold and measures of 30-second all-out power. Some of these measures also have typical error between repeated tests suitably low for tracking changes. Combining measures via multiple linear regression needs further investigation. In summary, measurement of boat speed, especially with a good GPS device, has adequate precision for monitoring training performance, but adjustment for environmental effects needs to be investigated. Time trials on the Concept II ergometer provide accurate estimates of a rower's physiological ability to output power, and some submaximal and brief maximal ergometer performance measures can be used frequently to monitor changes in this ability. On-water performance measured via instrumented skiffs that determine individual power output may eventually surpass measures derived from the Concept II.

No Evidence of Reaction Time Slowing in Autism Spectrum Disorder

ERIC Educational Resources Information Center

Ferraro, F. Richard

2016-01-01

A total of 32 studies comprising 238 simple reaction time and choice reaction time conditions were examined in individuals with autism spectrum disorder (n?=?964) and controls (n?=?1032). A Brinley plot/multiple regression analysis was performed on mean reaction times, regressing autism spectrum disorder performance onto the control performance as…

Sleep deprivation and time-on-task performance decrement in the rat psychomotor vigilance task.

PubMed

Oonk, Marcella; Davis, Christopher J; Krueger, James M; Wisor, Jonathan P; Van Dongen, Hans P A

2015-03-01

The rat psychomotor vigilance task (rPVT) was developed as a rodent analog of the human psychomotor vigilance task (hPVT). We examined whether rPVT performance displays time-on-task effects similar to those observed on the hPVT. The rPVT requires rats to respond to a randomly presented light stimulus to obtain a water reward. Rats were water deprived for 22 h prior to each 30-min rPVT session to motivate performance. We analyzed rPVT performance over time on task and as a function of the response-stimulus interval, at baseline and after sleep deprivation. The study was conducted in an academic research vivarium. Male Long-Evans rats were trained to respond to a 0.5 sec stimulus light within 3 sec of stimulus onset. Complete data were available for n = 20 rats. Rats performed the rPVT for 30 min at baseline and after 24 h total sleep deprivation by gentle handling. Compared to baseline, sleep deprived rats displayed increased performance lapses and premature responses, similar to hPVT lapses of attention and false starts. However, in contrast to hPVT performance, the time-on-task performance decrement was not significantly enhanced by sleep deprivation. Moreover, following sleep deprivation, rPVT response times were not consistently increased after short response-stimulus intervals. The rPVT manifests similarities to the hPVT in global performance outcomes, but not in post-sleep deprivation effects of time on task and response-stimulus interval. © 2015 Associated Professional Sleep Societies, LLC.

Early to Rise? The Effect of Daily Start Times on Academic Performance

ERIC Educational Resources Information Center

Edwards, Finley

2012-01-01

Local school districts often stagger daily start times for their schools in order to reduce busing costs. This paper uses data on all middle school students in Wake County, NC from 1999 to 2006 to identify the causal effect of daily start times on academic performance. Using variation in start times within schools over time, the effect is a two…

Can We Predict Cognitive Performance Decrements Due to Sleep Loss and the Recuperative Effects of Caffeine

DTIC Science & Technology

2015-10-14

such as timely short naps and caffeine, are often used to mitigate the effects of sleep loss on performance. However, the timing, duration, and dosage...loss and the restorative effects of different dosages of caffeine on a specific individual’s performance. When used as a decision-aid tool, this model...provides the means to maximize Warfighter cognitive performance, resulting in peak alertness and prolonged alertness at the desired times

Run-time parallelization and scheduling of loops

NASA Technical Reports Server (NTRS)

Saltz, Joel H.; Mirchandaney, Ravi; Crowley, Kay

1990-01-01

Run time methods are studied to automatically parallelize and schedule iterations of a do loop in certain cases, where compile-time information is inadequate. The methods presented involve execution time preprocessing of the loop. At compile-time, these methods set up the framework for performing a loop dependency analysis. At run time, wave fronts of concurrently executable loop iterations are identified. Using this wavefront information, loop iterations are reordered for increased parallelism. Symbolic transformation rules are used to produce: inspector procedures that perform execution time preprocessing and executors or transformed versions of source code loop structures. These transformed loop structures carry out the calculations planned in the inspector procedures. Performance results are presented from experiments conducted on the Encore Multimax. These results illustrate that run time reordering of loop indices can have a significant impact on performance. Furthermore, the overheads associated with this type of reordering are amortized when the loop is executed several times with the same dependency structure.

76 FR 25345 - Annual Assessment of the Status of Competition in the Market for the Delivery of Video Programming

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-04

... as of June 30 of the relevant year to monitor trends on an annual basis. To continue our time-series... video programming? 24. MVPD Performance. We seek comment on the information and time- series data we... Television Performance. We seek information and time- series data for the analysis of various performance...

Different motion cues are used to estimate time-to-arrival for frontoparallel and looming trajectories

PubMed Central

Calabro, Finnegan J.; Beardsley, Scott A.; Vaina, Lucia M.

2012-01-01

Estimation of time-to-arrival for moving objects is critical to obstacle interception and avoidance, as well as to timing actions such as reaching and grasping moving objects. The source of motion information that conveys arrival time varies with the trajectory of the object raising the question of whether multiple context-dependent mechanisms are involved in this computation. To address this question we conducted a series of psychophysical studies to measure observers’ performance on time-to-arrival estimation when object trajectory was specified by angular motion (“gap closure” trajectories in the frontoparallel plane), looming (colliding trajectories, TTC) or both (passage courses, TTP). We measured performance of time-to-arrival judgments in the presence of irrelevant motion, in which a perpendicular motion vector was added to the object trajectory. Data were compared to models of expected performance based on the use of different components of optical information. Our results demonstrate that for gap closure, performance depended only on the angular motion, whereas for TTC and TTP, both angular and looming motion affected performance. This dissociation of inputs suggests that gap closures are mediated by a separate mechanism than that used for the detection of time-to-collision and time-to-passage. We show that existing models of TTC and TTP estimation make systematic errors in predicting subject performance, and suggest that a model which weights motion cues by their relative time-to-arrival provides a better account of performance. PMID:22056519

A unified method for evaluating real-time computer controllers: A case study. [aircraft control

NASA Technical Reports Server (NTRS)

Shin, K. G.; Krishna, C. M.; Lee, Y. H.

1982-01-01

A real time control system consists of a synergistic pair, that is, a controlled process and a controller computer. Performance measures for real time controller computers are defined on the basis of the nature of this synergistic pair. A case study of a typical critical controlled process is presented in the context of new performance measures that express the performance of both controlled processes and real time controllers (taken as a unit) on the basis of a single variable: controller response time. Controller response time is a function of current system state, system failure rate, electrical and/or magnetic interference, etc., and is therefore a random variable. Control overhead is expressed as a monotonically nondecreasing function of the response time and the system suffers catastrophic failure, or dynamic failure, if the response time for a control task exceeds the corresponding system hard deadline, if any. A rigorous probabilistic approach is used to estimate the performance measures. The controlled process chosen for study is an aircraft in the final stages of descent, just prior to landing. First, the performance measures for the controller are presented. Secondly, control algorithms for solving the landing problem are discussed and finally the impact of the performance measures on the problem is analyzed.

Multiple Off-Ice Performance Variables Predict On-Ice Skating Performance in Male and Female Division III Ice Hockey Players

PubMed Central

Janot, Jeffrey M.; Beltz, Nicholas M.; Dalleck, Lance D.

2015-01-01

The purpose of this study was to determine if off-ice performance variables could predict on-ice skating performance in Division III collegiate hockey players. Both men (n = 15) and women (n = 11) hockey players (age = 20.5 ± 1.4 years) participated in the study. The skating tests were agility cornering S-turn, 6.10 m acceleration, 44.80 m speed, modified repeat skate, and 15.20 m full speed. Off-ice variables assessed were years of playing experience, height, weight and percent body fat and off-ice performance variables included vertical jump (VJ), 40-yd dash (36.58m), 1-RM squat, pro-agility, Wingate peak power and peak power percentage drop (% drop), and 1.5 mile (2.4km) run. Results indicated that 40-yd dash (36.58m), VJ, 1.5 mile (2.4km) run, and % drop were significant predictors of skating performance for repeat skate (slowest, fastest, and average time) and 44.80 m speed time, respectively. Four predictive equations were derived from multiple regression analyses: 1) slowest repeat skate time = 2.362 + (1.68 x 40-yd dash time) + (0.005 x 1.5 mile run), 2) fastest repeat skate time = 9.762 - (0.089 x VJ) - (0.998 x 40-yd dash time), 3) average repeat skate time = 7.770 + (1.041 x 40-yd dash time) - (0.63 x VJ) + (0.003 x 1.5 mile time), and 4) 47.85 m speed test = 7.707 - (0.050 x VJ) - (0.01 x % drop). It was concluded that selected off-ice tests could be used to predict on-ice performance regarding speed and recovery ability in Division III male and female hockey players. Key points The 40-yd dash (36.58m) and vertical jump tests are significant predictors of on-ice skating performance specific to speed. In addition to 40-yd dash and vertical jump, the 1.5 mile (2.4km) run for time and percent power drop from the Wingate anaerobic power test were also significant predictors of skating performance that incorporates the aspect of recovery from skating activity. Due to the specificity of selected off-ice variables as predictors of on-ice performance, coaches can elect to assess player performance off-ice and focus on other uses of valuable ice time for their individual teams. PMID:26336338

Time estimation as a secondary task to measure workload. [attention sharing effect on operator performance

NASA Technical Reports Server (NTRS)

Hart, S. G.

1975-01-01

Variation in the length of time productions and verbal estimates of duration was investigated to determine the influence of concurrent activity on operator time perception. The length of 10-, 20-, and 30-sec intervals produced while performing six different compensatory tracking tasks was significantly longer, 23% on the average, than those produced while performing no other task. Verbal estimates of session duration, taken at the end of each of 27 experimental sessions, reflected a parallel increase in subjective underestimation of the passage of time as the difficulty of the task performed increased. These data suggest that estimates of duration made while performing a manual control task provide stable and sensitive measures of the workload imposed by the primary task, with minimal interference.

Effect of modest pay-for-performance financial incentive on time-to-discharge summary dictation among medical residents.

PubMed

Wolk, Adam; Wang, Erwin; Horak, Bernard; Cloonan, Patricia; Adams, Michael; Moore, Eileen; Jaipaul, Chitra Komal; Brown, Gabrielle; Dasgupta, Dabanjan; Deluca, Danielle; Grossman, Mila

2013-01-01

Evaluate the effect of a modest financial incentive on time-to-discharge summary dictation among medicine residents. Pay-for-performance incentives are used in a number of health care settings. Studies are lacking on their use with medical residents and other trainees. Timely completion of discharge summaries is necessary for effective follow-up after hospitalization, and residents perform the majority of discharge summary dictations in academic medical centers. Medicine residents with the lowest average discharge-to-dictation time during their 1-month inpatient medicine ward rotation were rewarded with a $50 gift card. Discharge data were captured using an autopopulating electronic database. The average discharge-to-dictation time was reduced from 7.44 to 1.84 days, representing a 75.3% decrease. Almost 90% of discharge summary dictations were performed on the day of discharge. A modest financial incentive resulted in a marked improvement in the time-to-discharge summary dictation by medicine residents. Pay-for-performance programs may be an effective strategy for improving the quality and efficiency of patient care in academic medical centers.

Real-time simulation of a Doubly-Fed Induction Generator based wind power system on eMEGASimRTM Real-Time Digital Simulator

NASA Astrophysics Data System (ADS)

Boakye-Boateng, Nasir Abdulai

The growing demand for wind power integration into the generation mix prompts the need to subject these systems to stringent performance requirements. This study sought to identify the required tools and procedures needed to perform real-time simulation studies of Doubly-Fed Induction Generator (DFIG) based wind generation systems as basis for performing more practical tests of reliability and performance for both grid-connected and islanded wind generation systems. The author focused on developing a platform for wind generation studies and in addition, the author tested the performance of two DFIG models on the platform real-time simulation model; an average SimpowerSystemsRTM DFIG wind turbine, and a detailed DFIG based wind turbine using ARTEMiSRTM components. The platform model implemented here consists of a high voltage transmission system with four integrated wind farm models consisting in total of 65 DFIG based wind turbines and it was developed and tested on OPAL-RT's eMEGASimRTM Real-Time Digital Simulator.

Influence of sleep and meal schedules on performance peaks in competitive sprinters.

PubMed

Javierre, C; Calvo, M; Díez, A; Garrido, E; Segura, R; Ventura, J L

1996-08-01

The influence of sleep and meal schedules on performance in short distance running was assessed in a group of 8 national-class competition male sprinters. They were tested on Saturdays for five consecutive weeks. On each testing day, the performance time for an 80 m sprint was registered on eight different occasions during days 1 and 4, on 9 occasions on days 2 and 5, and on 7 occasions on day 3. On control days (days 1 and 4) performance gradually improved during the morning up to 13:00 h, decreased at 15:00 h, and again improved thereafter, with a maximum peak performance at 19:00 h. On day 2, in which sleep/wake cycles and meal-times were advanced for two hours, and on day 3, in which timetables were delayed for two hours, maximum peak performance was observed at 17:00 h and 21:00 h, respectively. At the time of maximum peak performance on both days a statistically significant improvement was observed as compared with the control day (day 2, p < 0.01; day 3, p = 0.001). On day 5, in which only the sleep/wake cycle was advanced for two hours, performance in the afternoon and evening was similar to that recorded on days 1 and 4. We observed that easy manipulation of sleep and meal schedules would allow competitive sprinters to synchronize peak power output with the time of the athletic event, increasing the chances for improvement in performance.

Laying the foundation for successful team performance trajectories: The roles of team charters and performance strategies.

PubMed

Mathieu, John E; Rapp, Tammy L

2009-01-01

This study examined the influences of team charters and performance strategies on the performance trajectories of 32 teams of master's of business administration students competing in a business strategy simulation over time. The authors extended existing theory on team development by demonstrating that devoting time to laying a foundation for both teamwork (i.e., team charters) and taskwork (performance strategies) can pay dividends in terms of more effective team performance over time. Using random coefficients growth modeling techniques, they found that teams with high-quality performance strategies outperformed teams with poorer quality strategies. However, a significant interaction between quality of the charters of teams and their performance strategies was found, such that the highest sustained performances were exhibited by teams that were high on both features. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

Performance Evaluation of a Firm Real-Time DataBase System

DTIC Science & Technology

1995-01-01

after its deadline has passed. StarBase differs from previous real-time database work in that a) it relies on a real - time operating system which...StarBase, running on a real - time operating system kernel, RT-Mach. We discuss how performance was evaluated in StarBase using the StarBase workload

AATA AOS evaluation : transfer and on-time performance study : before and after AOS implementation, October 1996 - May 1999

DOT National Transportation Integrated Search

1999-01-01

This study develops, using data before AOS in 1996 and 1997 and after AOS in 1998 and 1999, implementation data on AATAs on-time performance and vehicle-to-vehicle timing of transfers at four major transfer location. Systematic evaluation of on-ti...

Timing Recovery Strategies in Magnetic Recording Systems

NASA Astrophysics Data System (ADS)

Kovintavewat, Piya

At some point in a digital communications receiver, the received analog signal must be sampled. Good performance requires that these samples be taken at the right times. The process of synchronizing the sampler with the received analog waveform is known as timing recovery. Conventional timing recovery techniques perform well only when operating at high signal-to-noise ratio (SNR). Nonetheless, iterative error-control codes allow reliable communication at very low SNR, where conventional techniques fail. This paper provides a detailed review on the timing recovery strategies based on per-survivor processing (PSP) that are capable of working at low SNR. We also investigate their performance in magnetic recording systems because magnetic recording is a primary method of storage for a variety of applications, including desktop, mobile, and server systems. Results indicate that the timing recovery strategies based on PSP perform better than the conventional ones and are thus worth being employed in magnetic recording systems.

The Impact of a Rigorous Multiple Work Shift Schedule and Day Versus Night Shift Work on Reaction Time and Balance Performance in Female Nurses: A Repeated Measures Study.

PubMed

Thompson, Brennan J; Stock, Matt S; Banuelas, Victoria K; Akalonu, Chibuzo C

2016-07-01

The aim of this study was to determine the impact of a demanding work schedule involving long, cumulative work shifts on response time and balance-related performance outcomes and to evaluate the prevalence of musculoskeletal disorders between day and night shift working nurses. A questionnaire was used to identify the prevalence of past (12-month) and current (7-day) musculoskeletal disorders. Nurses worked three 12-hour work shifts in a 4-day period. Reaction time and balance tests were conducted before and after the work period. The work period induced impairments for reaction time, errors on reaction time tasks, and balance performance, independent of shift type. Musculoskeletal symptom prevalence was high in workers of both work shifts. Compressed work shifts caused performance-based fatigue in nurses. Reaction time and balance tests may be sensitive fatigue identification markers in nurses.

Laying the Foundation for Successful Team Performance Trajectories: The Roles of Team Charters and Performance Strategies

ERIC Educational Resources Information Center

Mathieu, John E.; Rapp, Tammy L.

2009-01-01

This study examined the influences of team charters and performance strategies on the performance trajectories of 32 teams of master's of business administration students competing in a business strategy simulation over time. The authors extended existing theory on team development by demonstrating that devoting time to laying a foundation for…

The Relationship between Cellular Phone Use, Performance, and Reaction Time among College Students: Implications for Cellular Phone Use while Driving

ERIC Educational Resources Information Center

Szyfman, Adam; Wanner, Gregory; Spencer, Leslie

2003-01-01

Two studies were performed to determine the relationship between cellular phone use and either reaction time or performance among college students. In the first study 60 undergraduates completed a computerized reaction time test. Mean reaction times were significantly higher when participants were talking on a cellular phone, either handheld or on…

Sleep to the beat: A nap favours consolidation of timing.

PubMed

Verweij, Ilse M; Onuki, Yoshiyuki; Van Someren, Eus J W; Van der Werf, Ysbrand D

2016-06-01

Growing evidence suggests that sleep is important for procedural learning, but few studies have investigated the effect of sleep on the temporal aspects of motor skill learning. We assessed the effect of a 90-min day-time nap on learning a motor timing task, using 2 adaptations of a serial interception sequence learning (SISL) task. Forty-two right-handed participants performed the task before and after a 90-min period of sleep or wake. Electroencephalography (EEG) was recorded throughout. The motor task consisted of a sequential spatial pattern and was performed according to 2 different timing conditions, that is, either following a sequential or a random temporal pattern. The increase in accuracy was compared between groups using a mixed linear regression model. Within the sleep group, performance improvement was modeled based on sleep characteristics, including spindle- and slow-wave density. The sleep group, but not the wake group, showed improvement in the random temporal, but especially and significantly more strongly in the sequential temporal condition. None of the sleep characteristics predicted improvement on either general of the timing conditions. In conclusion, a daytime nap improves performance on a timing task. We show that performance on the task with a sequential timing sequence benefits more from sleep than motor timing. More important, the temporal sequence did not benefit initial learning, because differences arose only after an offline period and specifically when this period contained sleep. Sleep appears to aid in the extraction of regularities for optimal subsequent performance. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Performance Trends During Sleep Deprivation on a Tilt-Based Control Task.

PubMed

Bolkhovsky, Jeffrey B; Ritter, Frank E; Chon, Ki H; Qin, Michael

2018-07-01

Understanding human behavior under the effects of sleep deprivation allows for the mitigation of risk due to reduced performance. To further this goal, this study investigated the effects of short-term sleep deprivation using a tilt-based control device and examined whether existing user models accurately predict targeting performance. A task in which the user tilts a surface to roll a ball into a target was developed to examine motor performance. A model was built to predict human performance for this task under various levels of sleep deprivation. Every 2 h, 10 subjects completed the task until they reached 24 h of wakefulness. Performance measurements of this task, which were based on Fitts' law, included movement time, task throughput, and time intercept. The model predicted significant performance decrements over the 24-h period with an increase in movement time (R2 = 0.61), a decrease in throughput (R2 = 0.57), and an increase in time intercept (R2 = 0.60). However, it was found that in experimental trials there was no significant change in movement time (R2 = 0.11), throughput (R2 = 0.15), or time intercept (R2 = 0.27). The results found were unexpected as performance decrement is frequently reported during sleep deprivation. These findings suggest a reexamination of the initial thought of sleep loss leading to a decrement in all aspects of performance.Bolkovsky JB, Ritter FE, Chon KH, Qin M. Performance trends during sleep deprivation on a tilt-based control task. Aerosp Med Hum Perform. 2018; 89(7):626-633.

Blue-Enriched Light Enhances Alertness but Impairs Accurate Performance in Evening Chronotypes Driving in the Morning.

PubMed

Rodríguez-Morilla, Beatriz; Madrid, Juan A; Molina, Enrique; Pérez-Navarro, José; Correa, Ángel

2018-01-01

Attention maintenance is highly demanding and typically leads to vigilance decrement along time on task. Therefore, performance in tasks involving vigilance maintenance for long periods, such as driving, tends to deteriorate over time. Cognitive performance has been demonstrated to fluctuate over 24 h of the day (known as circadian oscillations), thus showing peaks and troughs depending on the time of day (leading to optimal and suboptimal times of day, respectively). Consequently, vigilance decrements are more pronounced along time on task when it is performed at suboptimal times of day. According to research, light exposure (especially blue-enriched white) enhances alertness. Thus, it has been proposed to prevent the vigilance decrement under such adverse circumstances. We aimed to explore the effects of blue-enriched white light (vs. dim light) on the performance of a simulated driving task at a suboptimal time of day. A group of evening-types was tested at 8 am, as this chronotype had previously shown their largest vigilance decrement at that time. In the dim light condition, vigilance decrements were expected on both subjective (as increments in the Karolinska Sleepiness Scale scores) and behavioral measures [as slower reaction times (RTs) in the auditory Psychomotor Vigilance Task, slower RTs to unexpected events during driving, and deteriorated driving accuracy along time on task]. Physiological activation was expected to decrease (as indexed by an increase of the distal-proximal temperature gradient, DPG). Under blue-enriched white light, all these trends should be attenuated. Results from the control dim light condition replicated the vigilance decrement in all measures. Most important, the blue-enriched white light attenuated this decrement, leading to both lower DPG and faster RTs. However, it impaired accuracy of driving performance, and did not have any effect on subjective sleepiness. We conclude that exposure to blue-enriched light provides an effective countermeasure to enhance vigilance performance at suboptimal times of day, according to measures such as RTs. However, it should be considered that alerting effects of light could impair accuracy in precision tasks as keeping a proper car position. The current findings provide ergonomic implications for safety and fatigue related management systems.

Time series momentum and contrarian effects in the Chinese stock market

NASA Astrophysics Data System (ADS)

Shi, Huai-Long; Zhou, Wei-Xing

2017-10-01

This paper concentrates on the time series momentum or contrarian effects in the Chinese stock market. We evaluate the performance of the time series momentum strategy applied to major stock indices in mainland China and explore the relation between the performance of time series momentum strategies and some firm-specific characteristics. Our findings indicate that there is a time series momentum effect in the short run and a contrarian effect in the long run in the Chinese stock market. The performances of the time series momentum and contrarian strategies are highly dependent on the look-back and holding periods and firm-specific characteristics.

Visualization Improves Supraclavicular Access to the Subclavian Vein in a Mixed Reality Simulator.

PubMed

Sappenfield, Joshua Warren; Smith, William Brit; Cooper, Lou Ann; Lizdas, David; Gonsalves, Drew B; Gravenstein, Nikolaus; Lampotang, Samsun; Robinson, Albert R

2018-07-01

We investigated whether visual augmentation (3D, real-time, color visualization) of a procedural simulator improved performance during training in the supraclavicular approach to the subclavian vein, not as widely known or used as its infraclavicular counterpart. To train anesthesiology residents to access a central vein, a mixed reality simulator with emulated ultrasound imaging was created using an anatomically authentic, 3D-printed, physical mannequin based on a computed tomographic scan of an actual human. The simulator has a corresponding 3D virtual model of the neck and upper chest anatomy. Hand-held instruments such as a needle, an ultrasound probe, and a virtual camera controller are directly manipulated by the trainee and tracked and recorded with submillimeter resolution via miniature, 6 degrees of freedom magnetic sensors. After Institutional Review Board approval, 69 anesthesiology residents and faculty were enrolled and received scripted instructions on how to perform subclavian venous access using the supraclavicular approach based on anatomic landmarks. The volunteers were randomized into 2 cohorts. The first used real-time 3D visualization concurrently with trial 1, but not during trial 2. The second did not use real-time 3D visualization concurrently with trial 1 or 2. However, after trial 2, they observed a 3D visualization playback of trial 2 before performing trial 3 without visualization. An automated scoring system based on time, success, and errors/complications generated objective performance scores. Nonparametric statistical methods were used to compare the scores between subsequent trials, differences between groups (real-time visualization versus no visualization versus delayed visualization), and improvement in scores between trials within groups. Although the real-time visualization group demonstrated significantly better performance than the delayed visualization group on trial 1 (P = .01), there was no difference in gain scores, between performance on the first trial and performance on the final trial, that were dependent on group (P = .13). In the delayed visualization group, the difference in performance between trial 1 and trial 2 was not significant (P = .09); reviewing performance on trial 2 before trial 3 resulted in improved performance when compared to trial 1 (P < .0001). There was no significant difference in median scores (P = .13) between the real-time visualization and delayed visualization groups for the last trial after both groups had received visualization. Participants reported a significant improvement in confidence in performing supraclavicular access to the subclavian vein. Standard deviations of scores, a measure of performance variability, decreased in the delayed visualization group after viewing the visualization. Real-time visual augmentation (3D visualization) in the mixed reality simulator improved performance during supraclavicular access to the subclavian vein. No difference was seen in the final trial of the group that received real-time visualization compared to the group that had delayed visualization playback of their prior attempt. Training with the mixed reality simulator improved participant confidence in performing an unfamiliar technique.

The influence of spatial congruency and movement preparation time on saccade curvature in simultaneous and sequential dual-tasks.

PubMed

Moehler, Tobias; Fiehler, Katja

2015-11-01

Saccade curvature represents a sensitive measure of oculomotor inhibition with saccades curving away from covertly attended locations. Here we investigated whether and how saccade curvature depends on movement preparation time when a perceptual task is performed during or before saccade preparation. Participants performed a dual-task including a visual discrimination task at a cued location and a saccade task to the same location (congruent) or to a different location (incongruent). Additionally, we varied saccade preparation time (time between saccade cue and Go-signal) and the occurrence of the discrimination task (during saccade preparation=simultaneous vs. before saccade preparation=sequential). We found deteriorated perceptual performance in incongruent trials during simultaneous task performance while perceptual performance was unaffected during sequential task performance. Saccade accuracy and precision were deteriorated in incongruent trials during simultaneous and, to a lesser extent, also during sequential task performance. Saccades consistently curved away from covertly attended non-saccade locations. Saccade curvature was unaffected by movement preparation time during simultaneous task performance but decreased and finally vanished with increasing movement preparation time during sequential task performance. Our results indicate that the competing saccade plan to the covertly attended non-saccade location is maintained during simultaneous task performance until the perceptual task is solved while in the sequential condition, in which the discrimination task is solved prior to the saccade task, oculomotor inhibition decays gradually with movement preparation time. Copyright © 2015 Elsevier Ltd. All rights reserved.

An evidence accumulation model for conflict detection performance in a simulated air traffic control task.

PubMed

Neal, Andrew; Kwantes, Peter J

2009-04-01

The aim of this article is to develop a formal model of conflict detection performance. Our model assumes that participants iteratively sample evidence regarding the state of the world and accumulate it over time. A decision is made when the evidence reaches a threshold that changes over time in response to the increasing urgency of the task. Two experiments were conducted to examine the effects of conflict geometry and timing on response proportions and response time. The model is able to predict the observed pattern of response times, including a nonmonotonic relationship between distance at point of closest approach and response time, as well as effects of angle of approach and relative velocity. The results demonstrate that evidence accumulation models provide a good account of performance on a conflict detection task. Evidence accumulation models are a form of dynamic signal detection theory, allowing for the analysis of response times as well as response proportions, and can be used for simulating human performance on dynamic decision tasks.

A Study on the Effectiveness of Lockup-Free Caches for a Reduced Instruction Set Computer (RISC) Processor

DTIC Science & Technology

1992-09-01

to acquire or develop effective simulation tools to observe the behavior of a RISC implementation as it executes different types of programs . We choose...Performance Computer performance is measured by the amount of the time required to execute a program . Performance encompasses two types of time, elapsed time...and CPU time. Elapsed time is the time required to execute a program from start to finish. It includes latency of input/output activities such as

The effect of visual-motion time delays on pilot performance in a pursuit tracking task

NASA Technical Reports Server (NTRS)

Miller, G. K., Jr.; Riley, D. R.

1976-01-01

A study has been made to determine the effect of visual-motion time delays on pilot performance of a simulated pursuit tracking task. Three interrelated major effects have been identified: task difficulty, motion cues, and time delays. As task difficulty, as determined by airplane handling qualities or target frequency, increases, the amount of acceptable time delay decreases. However, when relatively complete motion cues are included in the simulation, the pilot can maintain his performance for considerably longer time delays. In addition, the number of degrees of freedom of motion employed is a significant factor.

Relationship between time management in construction industry and project management performance

NASA Astrophysics Data System (ADS)

Nasir, Najuwa; Nawi, Mohd Nasrun Mohd; Radzuan, Kamaruddin

2016-08-01

Nowadays, construction industry particularly in Malaysia struggle in achieving status of eminent time management for construction project. Project managers have a great responsibility to keep the project success under time of project completion. However, studies shows that delays especially in Malaysian construction industry still unresolved due to weakness in managing the project. In addition, quality of time management on construction projects is generally poor. Due to the progressively extended delays issue, time performance becomes an important subject to be explored to investigate delay factors. The method of this study is review of literature towards issues in construction industry which affecting time performance of project in general by focusing towards process involved for project management. Based on study, it was found that knowledge, commitment, cooperation are the main criteria as an overall to manage the project into a smooth process during project execution until completion. It can be concluded that, the strength between project manager and team members in these main criteria while conducting the project towards good time performance is highly needed. However, there is lack of establishment towards factors of poor time performance which strongly related with project management. Hence, this study has been conducted to establish factors of poor time performance and its relations with project management.

Effects of Math Anxiety and Perfectionism on Timed versus Untimed Math Testing in Mathematically Gifted Sixth Graders

ERIC Educational Resources Information Center

Tsui, Joanne M.; Mazzocco, Michele M. M.

2006-01-01

This study was designed to examine the effects of math anxiety and perfectionism on math performance, under timed testing conditions, among mathematically gifted sixth graders. We found that participants had worse math performance during timed versus untimed testing, but this difference was statistically significant only when the timed condition…

The More, the Better? The Impact of Instructional Time on Student Performance

ERIC Educational Resources Information Center

Cattaneo, Maria A.; Oggenfuss, Chantal; Wolter, Stefan C.

2017-01-01

Building on earlier work that explored within-student variation in hours of instruction across school subjects, we investigate the impact of instruction time on student test scores in Switzerland, as measured by the PISA 2009 test. Our results confirm the results of previous studies of a positive effect of instruction time on student performance.…

A little elastic for a better performance: kinesiotaping of the motor effector modulates neural mechanisms for rhythmic movements.

PubMed

Bravi, Riccardo; Quarta, Eros; Cohen, Erez J; Gottard, Anna; Minciacchi, Diego

2014-01-01

A rhythmic motor performance is brought about by an integration of timing information with movements. Investigations on the millisecond time scale distinguish two forms of time control, event-based timing and emergent timing. While event-based timing asserts the existence of a central internal timekeeper for the control of repetitive movements, the emergent timing perspective claims that timing emerges from dynamic control of nontemporal movements parameters. We have recently demonstrated that the precision of an isochronous performance, defined as performance of repeated movements having a uniform duration, was insensible to auditory stimuli of various characteristics (Bravi et al., 2014). Such finding has led us to investigate whether the application of an elastic therapeutic tape (Kinesio® Tex taping; KTT) used for treating athletic injuries and a variety of physical disorders, is able to reduce the timing variability of repetitive rhythmic movement. Young healthy subjects, tested with and without KTT, have participated in sessions in which sets of repeated isochronous wrist's flexion-extensions (IWFEs) were performed under various auditory conditions and during their recall. Kinematics was recorded and temporal parameters were extracted and analyzed. Our results show that the application of KTT decreases the variability of rhythmic movements by a 2-fold effect: on the one hand KTT provides extra proprioceptive information activating cutaneous mechanoreceptors, on the other KTT biases toward the emergent timing thus modulating the processes for rhythmic movements. Therefore, KTT appears able to render movements less audio dependent by relieving, at least partially, the central structures from time control and making available more resources for an augmented performance.

Sleep, circadian rhythms, and athletic performance.

PubMed

Thun, Eirunn; Bjorvatn, Bjørn; Flo, Elisabeth; Harris, Anette; Pallesen, Ståle

2015-10-01

Sleep deprivation and time of day are both known to influence performance. A growing body of research has focused on how sleep and circadian rhythms impact athletic performance. This review provides a systematic overview of this research. We searched three different databases for articles on these issues and inspected relevant reference lists. In all, 113 articles met our inclusion criteria. The most robust result is that athletic performance seems to be best in the evening around the time when the core body temperature typically is at its peak. Sleep deprivation was negatively associated with performance whereas sleep extension seems to improve performance. The effects of desynchronization of circadian rhythms depend on the local time at which performance occurs. The review includes a discussion of differences regarding types of skills involved as well as methodological issues. Copyright © 2014 Elsevier Ltd. All rights reserved.

5 CFR 551.211 - Effect of performing different work or duties for a temporary period of time on FLSA exemption...

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Effect of performing different work or... STANDARDS ACT Exemptions and Exclusions § 551.211 Effect of performing different work or duties for a temporary period of time on FLSA exemption status. (a) Applicability. Performing different work or duties...

Sustained attention in adult ADHD: time-on-task effects of various measures of attention.

PubMed

Tucha, Lara; Fuermaier, Anselm B M; Koerts, Janneke; Buggenthin, Rieka; Aschenbrenner, Steffen; Weisbrod, Matthias; Thome, Johannes; Lange, Klaus W; Tucha, Oliver

2017-02-01

Neuropsychological research on adults with ADHD showed deficits in various aspects of attention. However, the majority of studies failed to explore the change of performance over time, so-called time-on-task effects. As a consequence, little is known about sustained attention performance of adults with ADHD. The aim of the present study was therefore to test the hypothesis of sustained attention deficits of adults with ADHD. Twenty-nine adults with ADHD and 30 healthy individuals were assessed on four 20-min tests of sustained attention, measuring alertness, selective attention, divided attention and flexibility. The deterioration of performance over time (time-on-task effects) was compared between patients with ADHD and healthy individuals to conclude on sustained attention performance. Compared to healthy individuals, patients with ADHD showed significant deficits of medium size in selective attention and divided attention. Furthermore, medium sustained attention deficits was observed in measures of alertness, selective attention and divided attention. This study supports the notion of sustained attention deficits of adults with ADHD.

The cortisol awakening response is associated with performance of a serial sequence reaction time task.

PubMed

Hodyl, Nicolette A; Schneider, Luke; Vallence, Ann-Maree; Clow, Angela; Ridding, Michael C; Pitcher, Julia B

2016-02-01

There is emerging evidence of a relationship between the cortisol awakening response (CAR) and the neural mechanisms underlying learning and memory. The aim of this study was to determine whether the CAR is associated with acquisition, retention and overnight consolidation or improvement of a serial sequence reaction time task. Salivary samples were collected at 0, 15, 30 and 45 min after awakening in 39 healthy adults on 2 consecutive days. The serial sequence reaction time task was repeated each afternoon. Participants completed the perceived stress scale and provided salivary samples prior to testing for cortisol assessment. While the magnitude of the CAR (Z score) was not associated with either baseline performance or the timed improvement during task acquisition of the serial sequence task, a positive correlation was observed with reaction times during the stable performance phase on day 1 (r=0.373, p=0.019). Residuals derived from the relationship between baseline and stable phase reaction times on day 1 were used as a surrogate for the degree of learning: these residuals were also correlated with the CAR mean increase on day 1 (r=0.357, p=0.048). Task performance on day 2 was not associated with the CAR obtained on this same day. No association was observed between the perceived stress score, cortisol at testing or task performance. These data indicate that a smaller CAR in healthy adults is associated with a greater degree of learning and faster performance of a serial sequence reaction time task. These results support recognition of the CAR as an important factor contributing to cognitive performance throughout the day. Copyright © 2015 Elsevier B.V. All rights reserved.

Hyperoxia and Hypoxic Hypoxia Effects on Simple and Choice Reaction Times.

PubMed

Dart, Todd; Gallo, Megan; Beer, Jeremy; Fischer, Joseph; Morgan, Thomas; Pilmanis, Andrew

2017-12-01

Effects of exposure to hyperoxia (PiO2 > 105 mmHg), normoxia (PiO2 95-105 mmHg) and hypoxia (PiO2 < 95 mmHg) on simple and choice reaction performance tasks were evaluated. Ten subjects performed simple and choice reaction time tests (SRT and CRT, respectively) at ground level for 40 min (20 min normoxic, 20 min hyperoxic, randomly assigned), 3048 m (10,000 ft) for 75 min (15 min hyperoxic, 60 min hypoxic), 4572 m (15,000 ft) for 60 min (15 min hyperoxic, 45 min hypoxic), and 6096 m (20,000 ft) for 35 min (15 min hyperoxic, 20 min hypoxic). SRT and CRT tests were also conducted at ground level 1 h after normoxic rest (recovery) to assess any recovery time effect on these psychomotor tasks. Total response time (TRT) significantly increased by 15 ms to 25 ms at all three altitudes for both the SRT and CRT tasks. At and below 4572 m, the performance changes were gradual over the duration of the exposures, whereas at 6096 m these changes were immediate. After 1 h, no performance decrement was measured. There was no statistical evidence that ground-level performance on these tasks was improved in hyperoxic vs. normoxic conditions. Results suggest mild decrements in reaction time due to hypoxia may occur as low as 3048 m (10,000 ft) while hyperoxia showed no positive effect on accuracy or reaction time at ground level or higher when performing simple and choice psychomotor reaction tasks.Dart T, Gallo M, Beer J, Fischer J, Morgan T, Pilmanis A. Hyperoxia and hypoxic hypoxia effects on simple and choice reaction times. Aerosp Med Hum Perform. 2017; 88(12):1073-1080.

Effects of interest-major congruence, motivation, and academic performance on timely degree attainment.

PubMed

Allen, Jeff; Robbins, Steve

2010-01-01

Using longitudinal student data from 15 four-year (n = 3,072) and 13 (n = 788) two-year postsecondary institutions, the authors tested the effects of interest-major congruence, motivation, and 1st-year academic performance on timely degree completion. Findings suggest that interest-major congruence has a direct effect on timely degree completion at both institutional settings and that motivation has indirect effects (via 1st-year academic performance). The total effects of both interest-major congruence and motivation on timely degree completion underscore the importance of both constructs in understanding student adjustment and postsecondary success. Implications for theory and counseling practice are discussed.

A review of methodological factors in performance assessments of time-varying aircraft noise effects. [with annotated bibliography

NASA Technical Reports Server (NTRS)

Coates, G. D.; Alluisi, E. A.; Adkins, C. J., Jr.

1977-01-01

Literature on the effects of general noise on human performance is reviewed in an attempt to identify (1) those characteristics of noise that have been found to affect human performance; (2) those characteristics of performance most likely to be affected by the presence of noise, and (3) those characteristics of the performance situation typically associated with noise effects. Based on the characteristics identified, a theoretical framework is proposed that will permit predictions of possible effects of time-varying aircraft-type noise on complex human performance. An annotated bibliography of 50 articles is included.

How we can measure the non-driving-task engagement in automated driving: Comparing flow experience and workload.

PubMed

Ko, Sang Min; Ji, Yong Gu

2018-02-01

In automated driving, a driver can completely concentrate on non-driving-related tasks (NDRTs). This study investigated the flow experience of a driver who concentrated on NDRTs and tasks that induce mental workload under conditional automation. Participants performed NDRTs under different demand levels: a balanced demand-skill level (fit condition) to induce flow, low-demand level to induce boredom, and high-demand level to induce anxiety. In addition, they performed the additional N-Back task, which artificially induces mental workload. The results showed participants had the longest reaction time when they indicated the highest flow score, and had the longest gaze-on time, road-fixation time, hands-on time, and take-over time under the fit condition. Significant differences were not observed in the driver reaction times in the fit condition and the additional N-Back task, indicating that performing NDRTs that induce a high flow experience could influence driver reaction time similar to performing tasks with a high mental workload. Copyright © 2017. Published by Elsevier Ltd.

Fast algorithms for computing phylogenetic divergence time.

PubMed

Crosby, Ralph W; Williams, Tiffani L

2017-12-06

The inference of species divergence time is a key step in most phylogenetic studies. Methods have been available for the last ten years to perform the inference, but the performance of the methods does not yet scale well to studies with hundreds of taxa and thousands of DNA base pairs. For example a study of 349 primate taxa was estimated to require over 9 months of processing time. In this work, we present a new algorithm, AncestralAge, that significantly improves the performance of the divergence time process. As part of AncestralAge, we demonstrate a new method for the computation of phylogenetic likelihood and our experiments show a 90% improvement in likelihood computation time on the aforementioned dataset of 349 primates taxa with over 60,000 DNA base pairs. Additionally, we show that our new method for the computation of the Bayesian prior on node ages reduces the running time for this computation on the 349 taxa dataset by 99%. Through the use of these new algorithms we open up the ability to perform divergence time inference on large phylogenetic studies.

Understanding the role of mind wandering in stress-related working memory impairments.

PubMed

Banks, Jonathan B; Boals, Adriel

2017-08-01

Mind wandering has been identified as a possible cause for stress-related working memory (WM) task impairments following laboratory stressors. The current study attempted to induce mind wandering regarding negative, positive, or neutral events using an expressive writing task and examined the impact on WM task performance. We examined the role of mind wandering in understanding the impact of life stress on WM. Additionally, we explored the role of thought suppression on the relationship between mind wandering and WM. One hundred and fifty participants completed WM measures before (Time 1) and after (Time 2) the writing manipulation. The writing manipulation did not alter mind wandering or WM task performance. Time 1 WM predicted mind wandering during the Time 2 WM task, which subsequently predicted poorer Time 2 WM task performance. The impact of daily life stress on WM was mediated by mind wandering. Trait levels of thought suppression moderated the impact of mind wandering on WM. Specifically, higher levels of suppression resulted in stronger negative impact of mind wandering on WM task performance. Findings are discussed in terms of the impact of mind wandering on WM task performance.

Effect of "group spell" upon Shotokan black-belt performance of Heian kata.

PubMed

Layton, C; Moran, P

1999-10-01

11 experienced black-belt subjects were individually timed on each of the five Heian kata and then timed again when performing as part of a group. The pull of the group had a significant effect upon timing on two of the kata.

Mediators of methylphenidate effects on math performance in children with attention-deficit hyperactivity disorder.

PubMed

Froehlich, Tanya E; Antonini, Tanya N; Brinkman, William B; Langberg, Joshua M; Simon, John O; Adams, Ryan; Fredstrom, Bridget; Narad, Megan E; Kingery, Kathleen M; Altaye, Mekibib; Matheson, Heather; Tamm, Leanne; Epstein, Jeffery N

2014-01-01

Stimulant medications, such as methylphenidate (MPH), improve the academic performance of children with attention-deficit hyperactivity disorder (ADHD). However, the mechanism by which MPH exerts an effect on academic performance is unclear. We examined MPH effects on math performance and investigated possible mediation of MPH effects by changes in time on-task, inhibitory control, selective attention, and reaction time variability. Children with ADHD aged 7 to 11 years (N = 93) completed a timed math worksheet (with problems tailored to each individual's level of proficiency) and 2 neuropsychological tasks (Go/No-Go and Child Attention Network Test) at baseline, then participated in a 4-week, randomized, controlled, titration trial of MPH. Children were then randomly assigned to their optimal MPH dose or placebo for 1 week (administered double-blind) and repeated the math and neuropsychological tasks (posttest). Baseline and posttest videorecordings of children performing the math task were coded to assess time on-task. Children taking MPH completed 23 more math problems at posttest compared to baseline, whereas the placebo group completed 24 fewer problems on posttest versus baseline, but the effects on math accuracy (percent correct) did not differ. Path analyses revealed that only change in time on-task was a significant mediator of MPH's improvements in math productivity. MPH-derived math productivity improvements may be explained in part by increased time spent on-task, rather than improvements in neurocognitive parameters, such as inhibitory control, selective attention, or reaction time variability.

The Role of Time and Frequency in Future Systems

NASA Technical Reports Server (NTRS)

Stein, Samuel R.; Gifford, Al; Celano, Tom

1996-01-01

Over the past twenty years, the Global Positioning System (GPS) has revolutionized the performance and the geographical availability of time and frequency discrimination, while at the same time reducing the cost to the individual user. This paper examines the question of what comes next for time and frequency dissemination. The question has two motivations: How can improved performance be achieved in the future, and how can redundant sources of time and frequency be provided to critical systems? A model is developed for time and frequency dissemination based on the time management performed in GPS. Several candidate systems for future time and frequency distribution are identified. One system - SONET telecommunications - is discussed in detail. Performance requirements and hardware implementation are presented.

14 CFR 234.10 - Voluntary disclosure of on-time performance codes.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Voluntary disclosure of on-time performance codes. 234.10 Section 234.10 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS AIRLINE SERVICE QUALITY PERFORMANCE REPORTS § 234.10 Voluntary...

14 CFR 234.9 - Reporting of on-time performance codes.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Reporting of on-time performance codes. 234.9 Section 234.9 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS AIRLINE SERVICE QUALITY PERFORMANCE REPORTS § 234.9 Reporting of...

14 CFR 234.8 - Calculation of on-time performance codes.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Calculation of on-time performance codes. 234.8 Section 234.8 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS AIRLINE SERVICE QUALITY PERFORMANCE REPORTS § 234.8 Calculation...

Running with horizontal pulling forces: the benefits of towing.

PubMed

Grabowski, Alena M; Kram, Rodger

2008-10-01

Towing, or running with a horizontal pulling force, is a common technique used by adventure racing teams. During an adventure race, the slowest person on a team determines the team's overall performance. To improve overall performance, a faster runner tows a slower runner with an elastic cord attached to their waists. Our purpose was to create and validate a model that predicts the optimal towing force needed by two runners to achieve their best overall performance. We modeled the effects of towing forces between two runners that differ in solo 10-km performance time and/or body mass. We calculated the overall time that could be saved with towing for running distances of 10, 20, and 42.2-km based on equations from previous research. Then, we empirically tested our 10-km model on 15 runners. Towing improved overall running performance considerably and our model accurately predicted this performance improvement. For example, if two runners (a 70 kg runner with a 35 min solo 10-km time and a 70-kg runner with a 50-min solo 10-km time) maintain an optimal towing force throughout a 10-km race, they can improve overall performance by 15%, saving almost 8 min. Ultimately, the race performance time and body mass of each runner determine the optimal towing force.

Time response for sensor sensed to actuator response for mobile robotic system

NASA Astrophysics Data System (ADS)

Amir, N. S.; Shafie, A. A.

2017-11-01

Time and performance of a mobile robot are very important in completing the tasks given to achieve its ultimate goal. Tasks may need to be done within a time constraint to ensure smooth operation of a mobile robot and can result in better performance. The main purpose of this research was to improve the performance of a mobile robot so that it can complete the tasks given within time constraint. The problem that is needed to be solved is to minimize the time interval between sensor detection and actuator response. The research objective is to analyse the real time operating system performance of sensors and actuators on one microcontroller and on two microcontroller for a mobile robot. The task for a mobile robot for this research is line following with an obstacle avoidance. Three runs will be carried out for the task and the time between the sensors senses to the actuator responses were recorded. Overall, the results show that two microcontroller system have better response time compared to the one microcontroller system. For this research, the average difference of response time is very important to improve the internal performance between the occurrence of a task, sensors detection, decision making and actuator response of a mobile robot. This research helped to develop a mobile robot with a better performance and can complete task within the time constraint.

A microcosm of musical expression. III. Contributions of timing and dynamics to the aesthetic impression of pianists' performances of the initial measures of Chopin's Etude in E major.

PubMed

Repp, B H

1999-07-01

Four judges repeatedly assessed the overall aesthetic quality of more than 100 recorded performances of the opening of Chopin's Etude in E major on a 10-point scale. The judgments, which exhibited reasonable reliability and modest intercorrelations, were entered into regression analyses with 16 independent variables derived from earlier objective analyses of the expressive timing and dynamics of the performances [Repp, J. Acoust. Soc. Am. 104, 1085-1100 (1998); 105, 1972-1988 (1999)]. Only between 9% and 18% of the variance in the judges' ratings was accounted for. By contrast, timing variables accounted for 53% of the variance in one judge's ratings of synthesized performances that varied in timing only and mimicked the timing patterns of the original performances. These results indicate, first, that the aesthetic impression of the original recordings rested primarily on aspects other than those measured (such as texture, tone, or aspects of timing and dynamics that eluded the earlier analyses) and, second, that very different patterns of timing and dynamics are aesthetically acceptable for the same music, provided that other, aesthetically more crucial performance aspects are present.

Immediate Effects of Clock-Turn Strategy on the Pattern and Performance of Narrow Turning in Persons With Parkinson Disease.

PubMed

Yang, Wen-Chieh; Hsu, Wei-Li; Wu, Ruey-Meei; Lin, Kwan-Hwa

2016-10-01

Turning difficulty is common in people with Parkinson disease (PD). The clock-turn strategy is a cognitive movement strategy to improve turning performance in people with PD despite its effects are unverified. Therefore, this study aimed to investigate the effects of the clock-turn strategy on the pattern of turning steps, turning performance, and freezing of gait during a narrow turning, and how these effects were influenced by concurrent performance of a cognitive task (dual task). Twenty-five people with PD were randomly assigned to the clock-turn or usual-turn group. Participants performed the Timed Up and Go test with and without concurrent cognitive task during the medication OFF period. The clock-turn group performed the Timed Up and Go test using the clock-turn strategy, whereas participants in the usual-turn group performed in their usual manner. Measurements were taken during the 180° turn of the Timed Up and Go test. The pattern of turning steps was evaluated by step time variability and step time asymmetry. Turning performance was evaluated by turning time and number of turning steps. The number and duration of freezing of gait were calculated by video review. The clock-turn group had lower step time variability and step time asymmetry than the usual-turn group. Furthermore, the clock-turn group turned faster with fewer freezing of gait episodes than the usual-turn group. Dual task increased the step time variability and step time asymmetry in both groups but did not affect turning performance and freezing severity. The clock-turn strategy reduces turning time and freezing of gait during turning, probably by lowering step time variability and asymmetry. Dual task compromises the effects of the clock-turn strategy, suggesting a competition for attentional resources.Video Abstract available for more insights from the authors (see Supplemental Digital Content 1, http://links.lww.com/JNPT/A141).

A storage scheme for the real-time database supporting the on-line commitment

NASA Astrophysics Data System (ADS)

Dai, Hong-bin; Jing, Yu-jian; Wang, Hui

2013-07-01

The modern SCADA (Supervisory Control and Data acquisition) systems have been applied to various aspects of everyday life. As the time goes on, the requirements of the applications of the systems vary. Thus the data structure of the real-time database, which is the core of a SCADA system, often needs modification. As a result, the commitment consisting of a sequence of configuration operations modifying the data structure of the real-time database is performed from time to time. Though it is simple to perform the off-line commitment by first stopping and then restarting the system, during which all the data in the real-time database are reconstructed. It is much more preferred or in some cases even necessary to perform the on-line commitment, during which the real-time database can still provide real-time service and the system continues working normally. In this paper, a storage scheme of the data in the real-time database is proposed. It helps the real-time database support its on-line commitment, during which real-time service is still available.

Do repeated assessments of performance status improve predictions for risk of death among patients with cancer? A population-based cohort study.

PubMed

Su, Jiandong; Barbera, Lisa; Sutradhar, Rinku

2015-06-01

Prior work has utilized longitudinal information on performance status to demonstrate its association with risk of death among cancer patients; however, no study has assessed whether such longitudinal information improves the predictions for risk of death. To examine whether the use of repeated performance status assessments improve predictions for risk of death compared to using only performance status assessment at the time of cancer diagnosis. This was a population-based longitudinal study of adult outpatients who had a cancer diagnosis and had at least one assessment of performance status. To account for each patient's changing performance status over time, we implemented a Cox model with a time-varying covariate for performance status. This model was compared to a Cox model using only a time-fixed (baseline) covariate for performance status. The regression coefficients of each model were derived based on a randomly selected 60% of patients, and then, the predictive ability of each model was assessed via concordance probabilities when applied to the remaining 40% of patients. Our study consisted of 15,487 cancer patients with over 53,000 performance status assessments. The utilization of repeated performance status assessments improved predictions for risk of death compared to using only the performance status assessment taken at diagnosis. When studying the hazard of death among patients with cancer, if available, researchers should incorporate changing information on performance status scores, instead of simply baseline information on performance status. © The Author(s) 2015.

Patients with Duchenne and Becker muscular dystrophies are not more asymmetrical than healthy controls on timed performance of upper limb tasks

PubMed Central

Artilheiro, M.C.; Sá, C.S.C.; Fávero, F.M.; Caromano, F.A.; Voos, M.C.

2017-01-01

This study aimed to investigate possible asymmetries and relationships between performance of dominant and non-dominant upper limbs (UL) in patients with Duchenne and Becker muscular dystrophies (DMD/BMD), to compare UL performance of patients and healthy subjects and to investigate the relationship between timed performance of UL and age, motor function and muscle strength in DMD/BMD patients. Sixteen patients with DMD and 3 with BMD were evaluated with Jebsen-Taylor Test (timed performance), Vignos scale and Dimension 3 of Motor Function Measure (motor function), and Medical Research Council scale (muscle strength) on a single session. ANOVA showed no asymmetry between dominant and non-dominant UL, except in the writing subtest, in patients and in healthy controls. There were relationships between dominant and non-dominant UL performances. Correlations between timed performance, motor function and muscle strength were found, but age was not correlated with these variables. These findings may reduce the assessment time, prevent fatigue and provide more accurate clinical reasoning involving UL in DMD/BMD treatment. PMID:28746422

The effects of time pressure on chess skill: an investigation into fast and slow processes underlying expert performance.

PubMed

van Harreveld, Frenk; Wagenmakers, Eric-Jan; van der Maas, Han L J

2007-09-01

The ability to play chess is generally assumed to depend on two types of processes: slow processes such as search, and fast processes such as pattern recognition. It has been argued that an increase in time pressure during a game selectively hinders the ability to engage in slow processes. Here we study the effect of time pressure on expert chess performance in order to test the hypothesis that compared to weak players, strong players depend relatively heavily on fast processes. In the first study we examine the performance of players of various strengths at an online chess server, for games played under different time controls. In a second study we examine the effect of time controls on performance in world championship matches. Both studies consistently show that skill differences between players become less predictive of the game outcome as the time controls are tightened. This result indicates that slow processes are at least as important for strong players as they are for weak players. Our findings pose a challenge for current theorizing in the field of expertise and chess.

Time taken as a determinant of advancement in Shotokan karate black-belt Heian kata performance.

PubMed

Layton, C; Avenell, L

1999-12-01

30 experienced black-belt subjects were individually timed on each of the five Heian kata. Significant relationships were found between years of training and increased performance time on all the kata and for four with age controlled. The multiple correlation was significant.

The Effects of Extended Time on Writing Performance

ERIC Educational Resources Information Center

Goegan, Lauren D.; Harrison, Gina L.

2017-01-01

The effects of extended time on the writing performance of university students with learning disabilities (LD) was examined. Thirty-eight students (19 LD; 19 non-LD) completed a collection of cognitive, linguistic, and literacy measures, and wrote essays under regular and extended time conditions. Limited evidence was found to support the…

Can tutoring improve performance on a reasoning task under deadline conditions?

PubMed

Osman, Magda

2007-03-01

The present study examined the effectiveness of a tutoring technique that has been used to identify and address participants' misunderstandings in Wason's selection task. In particular, the study investigated whether the technique would lead to improvements in performance when the task was presented in a deadline format (a condition in which time restrictions are imposed). In Experiment 1, the effects of tutoring on performance were compared in free time (conditions in which no time restrictions are imposed) and deadline task formats. In Experiment 2, improvements in performance were studied in deadline task formats, in which the tutoring and test phases were separated by an interval of 1 day. The results suggested that tutoring improved performance on the selection task under deadline and in free time conditions. Additionally, the study showed that participants made errors because they had misinterpreted the task. With tutoring, they were able to modify their initial misunderstandings.

Timed Online Tests: Do Students Perform Better with More Time?

ERIC Educational Resources Information Center

Portolese, Laura; Krause, Jackie; Bonner, Julie

2016-01-01

This article focuses on timed tests and specifically on whether increased time enhances test performance. Three courses during the Winter 2015 term (quizzes n = 573) and three courses over the Spring 2015 term (quizzes n = 600) comprised this sample. Students were given the same tests, but the experimental group (Spring 2015) was given 50% more…

Sex differences in pacing during ‘Ultraman Hawaii’

PubMed Central

Nikolaidis, Pantelis T.

2016-01-01

Background To date, little is known for pacing in ultra-endurance athletes competing in a non-stop event and in a multi-stage event, and especially, about pacing in a multi-stage event with different disciplines during the stages. Therefore, the aim of the present study was to examine the effect of age, sex and calendar year on triathlon performance and variation of performance by events (i.e., swimming, cycling 1, cycling 2 and running) in ‘Ultraman Hawaii’ held between 1983 and 2015. Methods Within each sex, participants were grouped in quartiles (i.e., Q1, Q2, Q3 and Q4) with Q1 being the fastest (i.e., lowest overall time) and Q4 the slowest (i.e., highest overall time). To compare performance among events (i.e., swimming, cycling 1, cycling 2 and running), race time in each event was converted in z score and this value was used for further analysis. Results A between-within subjects ANOVA showed a large sex × event (p = 0.015, η2 = 0.014) and a medium performance group × event interaction (p = 0.001, η2 = 0.012). No main effect of event on performance was observed (p = 0.174, η2 = 0.007). With regard to the sex × event interaction, three female performance groups (i.e., Q2, Q3 and Q4) increased race time from swimming to cycling 1, whereas only one male performance group (Q4) revealed a similar trend. From cycling 1 to cycling 2, the two slower female groups (Q3 and Q4) and the slowest male group (Q4) increased raced time. In women, the fastest group decreased (i.e., improved) race time from swimming to cycling 1 and thereafter, maintained performance, whereas in men, the fastest group decreased race time till cycling 2 and increased it in the running. Conclusion In summary, women pace differently than men during ‘Ultraman Hawaii’ where the fastest women decreased performance on day 1 and could then maintain on day 2 and 3, whereas the fastest men worsened performance on day 1 and 2 but improved on day 3. PMID:27703854

Analysis method comparison of on-time and on-budget data.

DOT National Transportation Integrated Search

2007-02-01

New Mexico Department of Transportation (NMDOT) results for On-Time and On-Budget performance measures as reported in (AASHTO/SCoQ) NCHRP 20-24(37) Project Measuring Performance Among State DOTs (Phase I) are lower than construction personnel kno...

Visualizations of Travel Time Performance Based on Vehicle Reidentification Data

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

Young, Stanley Ernest; Sharifi, Elham; Day, Christopher M.

This paper provides a visual reference of the breadth of arterial performance phenomena based on travel time measures obtained from reidentification technology that has proliferated in the past 5 years. These graphical performance measures are revealed through overlay charts and statistical distribution as revealed through cumulative frequency diagrams (CFDs). With overlays of vehicle travel times from multiple days, dominant traffic patterns over a 24-h period are reinforced and reveal the traffic behavior induced primarily by the operation of traffic control at signalized intersections. A cumulative distribution function in the statistical literature provides a method for comparing traffic patterns from variousmore » time frames or locations in a compact visual format that provides intuitive feedback on arterial performance. The CFD may be accumulated hourly, by peak periods, or by time periods specific to signal timing plans that are in effect. Combined, overlay charts and CFDs provide visual tools with which to assess the quality and consistency of traffic movement for various periods throughout the day efficiently, without sacrificing detail, which is a typical byproduct of numeric-based performance measures. These methods are particularly effective for comparing before-and-after median travel times, as well as changes in interquartile range, to assess travel time reliability.« less

Mental Fatigue Impairs Soccer-Specific Physical and Technical Performance.

PubMed

Smith, Mitchell R; Coutts, Aaron J; Merlini, Michele; Deprez, Dieter; Lenoir, Matthieu; Marcora, Samuele M

2016-02-01

To investigate the effects of mental fatigue on soccer-specific physical and technical performance. This investigation consisted of two separate studies. Study 1 assessed the soccer-specific physical performance of 12 moderately trained soccer players using the Yo-Yo Intermittent Recovery Test, Level 1 (Yo-Yo IR1). Study 2 assessed the soccer-specific technical performance of 14 experienced soccer players using the Loughborough Soccer Passing and Shooting Tests (LSPT, LSST). Each test was performed on two occasions and preceded, in a randomized, counterbalanced order, by 30 min of the Stroop task (mentally fatiguing treatment) or 30 min of reading magazines (control treatment). Subjective ratings of mental fatigue were measured before and after treatment, and mental effort and motivation were measured after treatment. Distance run, heart rate, and ratings of perceived exertion were recorded during the Yo-Yo IR1. LSPT performance time was calculated as original time plus penalty time. LSST performance was assessed using shot speed, shot accuracy, and shot sequence time. Subjective ratings of mental fatigue and effort were higher after the Stroop task in both studies (P < 0.001), whereas motivation was similar between conditions. This mental fatigue significantly reduced running distance in the Yo-Yo IR1 (P < 0.001). No difference in heart rate existed between conditions, whereas ratings of perceived exertion were significantly higher at iso-time in the mental fatigue condition (P < 0.01). LSPT original time and performance time were not different between conditions; however, penalty time significantly increased in the mental fatigue condition (P = 0.015). Mental fatigue also impaired shot speed (P = 0.024) and accuracy (P < 0.01), whereas shot sequence time was similar between conditions. Mental fatigue impairs soccer-specific running, passing, and shooting performance.

The influence of physical and cognitive factors on reactive agility performance in men basketball players.

PubMed

Scanlan, Aaron; Humphries, Brendan; Tucker, Patrick S; Dalbo, Vincent

2014-01-01

This study explored the influence of physical and cognitive measures on reactive agility performance in basketball players. Twelve men basketball players performed multiple sprint, Change of Direction Speed Test, and Reactive Agility Test trials. Pearson's correlation analyses were used to determine relationships between the predictor variables (stature, mass, body composition, 5-m, 10-m and 20-m sprint times, peak speed, closed-skill agility time, response time and decision-making time) and reactive agility time (response variable). Simple and stepwise regression analyses determined the individual influence of each predictor variable and the best predictor model for reactive agility time. Morphological (r = -0.45 to 0.19), sprint (r = -0.40 to 0.41) and change-of-direction speed measures (r = 0.43) had small to moderate correlations with reactive agility time. Response time (r = 0.76, P = 0.004) and decision-making time (r = 0.58, P = 0.049) had large to very large relationships with reactive agility time. Response time was identified as the sole predictor variable for reactive agility time in the stepwise model (R(2) = 0.58, P = 0.004). In conclusion, cognitive measures had the greatest influence on reactive agility performance in men basketball players. These findings suggest reaction and decision-making drills should be incorporated in basketball training programmes.

The Relationship between Video Game Use and a Performance-Based Measure of Persistence

ERIC Educational Resources Information Center

Ventura, Matthew; Shute, Valerie; Zhao, Weinan

2013-01-01

An online performance-based measure of persistence was developed using anagrams and riddles. Persistence was measured by recording the time spent on unsolved anagrams and riddles. Time spent on unsolved problems was correlated to a self-report measure of persistence. Additionally, frequent video game players spent longer times on unsolved problems…

Effects of Interest-Major Congruence, Motivation, and Academic Performance on Timely Degree Attainment

ERIC Educational Resources Information Center

Allen, Jeff; Robbins, Steve

2010-01-01

Using longitudinal student data from 15 four-year (n = 3,072) and 13 (n = 788) two-year postsecondary institutions, the authors tested the effects of interest-major congruence, motivation, and 1st-year academic performance on timely degree completion. Findings suggest that interest-major congruence has a direct effect on timely degree completion…

Assessment Timing: Student Preferences and Its Impact on Performance

ERIC Educational Resources Information Center

McManus, Richard

2016-01-01

Students on a first year undergraduate economics module were given the choice of when to sit their first assessment in the subject in order to determine both preferences over assessment timing, and the impact of timing on performance. Clear preferences of having this option were shown (only 2% of students stated to be indifferent) with those more…

Carbohydrates for Soccer: A Focus on Skilled Actions and Half-Time Practices

PubMed Central

Hills, Samuel P.; Russell, Mark

2017-01-01

Carbohydrate consumption is synonymous with soccer performance due to the established effects on endogenous energy store preservation, and physical capacity maintenance. For performance-enhancement purposes, exogenous energy consumption (in the form of drinks, bars, gels and snacks) is recommended on match-day; specifically, before and during match-play. Akin to the demands of soccer, limited opportunities exist to consume carbohydrates outside of scheduled breaks in competition, such as at half-time. The link between cognitive function and blood glucose availability suggests that carbohydrates may influence decision-making and technical proficiency (e.g., soccer skills). However, relatively few reviews have focused on technical, as opposed to physical, performance while also addressing the practicalities associated with carbohydrate consumption when limited in-play feeding opportunities exist. Transient physiological responses associated with reductions in activity prevalent in scheduled intra-match breaks (e.g., half-time) likely have important consequences for practitioners aiming to optimize match-day performance. Accordingly, this review evaluated novel developments in soccer literature regarding (1) the ergogenic properties of carbohydrates for skill performance; and (2) novel considerations concerning exogenous energy provision during half-time. Recommendations are made to modify half-time practices in an aim to enhance subsequent performance. Viable future research opportunities exist regarding a deeper insight into carbohydrate provision on match-day. PMID:29295583

Changes in Shotokan karate black-belt Heian kata performance times: a longitudinal study.

PubMed

Layton, C; Lawrence, J M; Moran, P

1999-12-01

10 experienced black-belt subjects were individually timed on each of the five Heian kata and then timed again four years later. Performance time increased significantly in four of the kata, and this was interpreted as a positive progression.

Wireless data collection system for travel time estimation and traffic performance evaluation.

DOT National Transportation Integrated Search

2010-09-01

Having accurate and continually updated travel time and other performance data for the road and highway system has many benefits. From the perspective of the road users, having real-time updates on travel times will permit better travel and route pla...

Only time will tell: the changing relationships between LMX, job performance, and justice.

PubMed

Park, Sanghee; Sturman, Michael C; Vanderpool, Chelsea; Chan, Elisa

2015-05-01

Although it has been argued that leader-member exchange (LMX) is a phenomenon that develops over time, the existing LMX literature is largely cross-sectional in nature. Yet, there is a great need for unraveling how LMX develops over time. To address this issue in the LMX literature, we examine the relationships of LMX with 2 variables known for changing over time: job performance and justice perceptions. On the basis of current empirical findings, a simulation deductively shows that LMX develops over time, but differently in early stages versus more mature stages. Our findings also indicate that performance and justice trends affect LMX. Implications for LMX theory and for longitudinal research on LMX, performance, and justice are discussed. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Age and education influence the performance of elderly women on the dual-task Timed Up and Go test.

PubMed

Gomes, Gisele de Cássia; Teixeira-Salmela, Luci Fuscaldi; Fonseca, Bruna Espeschit; Freitas, Flávia Alexandra Silveira de; Fonseca, Maria Luísa Morais; Pacheco, Bruna Débora; Gonçalves, Marisa Rocha; Caramelli, Paulo

2015-03-01

Gait variability is related to functional decline in the elderly. The dual-task Timed Up and Go Test (TUG-DT) reflects the performance in daily activities. Objective To evaluate the differences in time to perform the TUG with and without DT in elderly women with different ages and levels of education and physical activity. Method Ninety-two elderly women perfomed the TUG at usual and fast speeds, with and without motor and cognitive DT. Results Increases in the time to perform the TUG-DT were observed at older ages and lower educational levels, but not at different levels of physical activity. More educated women performed the test faster with and without DT at both speeds. When age was considered, significant differences were found only for the TUG-DT at both speeds. Conclusion Younger women with higher education levels demonstrated better performances on the TUG-DT.

Cognitive Determinants of Academic Performance in Nigerian Pharmacy Schools.

PubMed

Ubaka, Chukwuemeka M; Sansgiry, Sujit S; Ukwe, Chinwe V

2015-09-25

Objective. To evaluate cognitive factors that might influence academic performance of students in Nigerian pharmacy schools. Methods. A cross-sectional, multi-center survey of Nigerian pharmacy students from 7 schools of pharmacy was conducted using 2 validated questionnaires measuring cognitive constructs such as test anxiety, academic competence, test competence, time management, and strategic study habits. Results. Female students and older students scored significantly better on time management skills and study habits, respectively. Test anxiety was negatively associated with academic performance while test competence, academic competence, and time management were positively associated with academic performance. These 4 constructs significantly discriminated between the lower and higher performing students, with the first 2 contributing to the most differences. Conclusion. Test and academic competence, test anxiety, and time management were significant factors associated with low and high academic performance among Nigerian pharmacy students. The study also demonstrated the significant effects of age, gender, and marital status on these constructs.

Cognitive Determinants of Academic Performance in Nigerian Pharmacy Schools

PubMed Central

Sansgiry, Sujit S.; Ukwe, Chinwe V.

2015-01-01

Objective. To evaluate cognitive factors that might influence academic performance of students in Nigerian pharmacy schools. Methods. A cross-sectional, multi-center survey of Nigerian pharmacy students from 7 schools of pharmacy was conducted using 2 validated questionnaires measuring cognitive constructs such as test anxiety, academic competence, test competence, time management, and strategic study habits. Results. Female students and older students scored significantly better on time management skills and study habits, respectively. Test anxiety was negatively associated with academic performance while test competence, academic competence, and time management were positively associated with academic performance. These 4 constructs significantly discriminated between the lower and higher performing students, with the first 2 contributing to the most differences. Conclusion. Test and academic competence, test anxiety, and time management were significant factors associated with low and high academic performance among Nigerian pharmacy students. The study also demonstrated the significant effects of age, gender, and marital status on these constructs. PMID:27168614

Predictive validity of driving-simulator assessments following traumatic brain injury: a preliminary study.

PubMed

Lew, Henry L; Poole, John H; Lee, Eun Ha; Jaffe, David L; Huang, Hsiu-Chen; Brodd, Edward

2005-03-01

To evaluate whether driving simulator and road test evaluations can predict long-term driving performance, we conducted a prospective study on 11 patients with moderate to severe traumatic brain injury. Sixteen healthy subjects were also tested to provide normative values on the simulator at baseline. At their initial evaluation (time-1), subjects' driving skills were measured during a 30-minute simulator trial using an automated 12-measure Simulator Performance Index (SPI), while a trained observer also rated their performance using a Driving Performance Inventory (DPI). In addition, patients were evaluated on the road by a certified driving evaluator. Ten months later (time-2), family members observed patients driving for at least 3 hours over 4 weeks and rated their driving performance using the DPI. At time-1, patients were significantly impaired on automated SPI measures of driving skill, including: speed and steering control, accidents, and vigilance to a divided-attention task. These simulator indices significantly predicted the following aspects of observed driving performance at time-2: handling of automobile controls, regulation of vehicle speed and direction, higher-order judgment and self-control, as well as a trend-level association with car accidents. Automated measures of simulator skill (SPI) were more sensitive and accurate than observational measures of simulator skill (DPI) in predicting actual driving performance. To our surprise, the road test results at time-1 showed no significant relation to driving performance at time-2. Simulator-based assessment of patients with brain injuries can provide ecologically valid measures that, in some cases, may be more sensitive than a traditional road test as predictors of long-term driving performance in the community.

Analysis of musical expression in audio signals

NASA Astrophysics Data System (ADS)

Dixon, Simon

2003-01-01

In western art music, composers communicate their work to performers via a standard notation which specificies the musical pitches and relative timings of notes. This notation may also include some higher level information such as variations in the dynamics, tempo and timing. Famous performers are characterised by their expressive interpretation, the ability to convey structural and emotive information within the given framework. The majority of work on audio content analysis focusses on retrieving score-level information; this paper reports on the extraction of parameters describing the performance, a task which requires a much higher degree of accuracy. Two systems are presented: BeatRoot, an off-line beat tracking system which finds the times of musical beats and tracks changes in tempo throughout a performance, and the Performance Worm, a system which provides a real-time visualisation of the two most important expressive dimensions, tempo and dynamics. Both of these systems are being used to process data for a large-scale study of musical expression in classical and romantic piano performance, which uses artificial intelligence (machine learning) techniques to discover fundamental patterns or principles governing expressive performance.

Linking melodic expectation to expressive performance timing and perceived musical tension.

PubMed

Gingras, Bruno; Pearce, Marcus T; Goodchild, Meghan; Dean, Roger T; Wiggins, Geraint; McAdams, Stephen

2016-04-01

This research explored the relations between the predictability of musical structure, expressive timing in performance, and listeners' perceived musical tension. Studies analyzing the influence of expressive timing on listeners' affective responses have been constrained by the fact that, in most pieces, the notated durations limit performers' interpretive freedom. To circumvent this issue, we focused on the unmeasured prelude, a semi-improvisatory genre without notated durations. In Experiment 1, 12 professional harpsichordists recorded an unmeasured prelude on a harpsichord equipped with a MIDI console. Melodic expectation was assessed using a probabilistic model (IDyOM [Information Dynamics of Music]) whose expectations have been previously shown to match closely those of human listeners. Performance timing information was extracted from the MIDI data using a score-performance matching algorithm. Time-series analyses showed that, in a piece with unspecified note durations, the predictability of melodic structure measurably influenced tempo fluctuations in performance. In Experiment 2, another 10 harpsichordists, 20 nonharpsichordist musicians, and 20 nonmusicians listened to the recordings from Experiment 1 and rated the perceived tension continuously. Granger causality analyses were conducted to investigate predictive relations among melodic expectation, expressive timing, and perceived tension. Although melodic expectation, as modeled by IDyOM, modestly predicted perceived tension for all participant groups, neither of its components, information content or entropy, was Granger causal. In contrast, expressive timing was a strong predictor and was Granger causal. However, because melodic expectation was also predictive of expressive timing, our results outline a complete chain of influence from predictability of melodic structure via expressive performance timing to perceived musical tension. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

The effect of visual-motion time-delays on pilot performance in a simulated pursuit tracking task

NASA Technical Reports Server (NTRS)

Miller, G. K., Jr.; Riley, D. R.

1977-01-01

An experimental study was made to determine the effect on pilot performance of time delays in the visual and motion feedback loops of a simulated pursuit tracking task. Three major interrelated factors were identified: task difficulty either in the form of airplane handling qualities or target frequency, the amount and type of motion cues, and time delay itself. In general, the greater the task difficulty, the smaller the time delay that could exist without degrading pilot performance. Conversely, the greater the motion fidelity, the greater the time delay that could be tolerated. The effect of motion was, however, pilot dependent.

Robust control of flexible space vehicles with minimum structural excitation: On-off pulse control of flexible space vehicles

NASA Technical Reports Server (NTRS)

Wie, Bong; Liu, Qiang

1992-01-01

Both feedback and feedforward control approaches for uncertain dynamical systems (in particular, with uncertainty in structural mode frequency) are investigated. The control objective is to achieve a fast settling time (high performance) and robustness (insensitivity) to plant uncertainty. Preshaping of an ideal, time optimal control input using a tapped-delay filter is shown to provide a fast settling time with robust performance. A robust, non-minimum-phase feedback controller is synthesized with particular emphasis on its proper implementation for a non-zero set-point control problem. It is shown that a properly designed, feedback controller performs well, as compared with a time optimal open loop controller with special preshaping for performance robustness. Also included are two separate papers by the same authors on this subject.

The culture of time in neuropsychological assessment: exploring the effects of culture-specific time attitudes on timed test performance in Russian and American samples.

PubMed

Agranovich, Anna V; Panter, A T; Puente, Antonio E; Touradji, Pegah

2011-07-01

Cultural differences in time attitudes and their effect on timed neuropsychological test performance were examined in matched non-clinical samples of 100 Russian and American adult volunteers using 8 tests that were previously reported to be relatively free of cultural bias: Color Trails Test (CTT); Ruff Figural Fluency Test (RFFT); Symbol Digit Modalities Test (SDMT); and Tower of London-Drexel Edition (ToL(Dx)). A measure of time attitudes, the Culture of Time Inventory (COTI-33) was used to assess time attitudes potentially affecting time-limited testing. Americans significantly outscored Russians on CTT, SDMT, and ToL(Dx) (p,.05) while differences in RFFT scores only approached statistical significance. Group differences also emerged in COTI-33 factor scores, which partially mediated differences in performance on CTT-1, SDMT, and ToL(Dx) initiation time, but did not account for the effect of culture on CTT-2. Significant effect of culture was revealed in ratings of familiarity with testing procedures that was negatively related to CTT, ToL(Dx), and SDMT scores. Current findings indicated that attitudes toward time may influence results of time limited testing and suggested that individuals who lack familiarity with timed testing procedures tend to obtain lower scores on timed tests.

Use and Rationale of Media Types in Performance-Centered Design.

ERIC Educational Resources Information Center

Schubert, Dave

2002-01-01

Focuses on the convergent rationale and use of media within performance centered design and how that can affect user performance using real-time electronic performance support system appliance design. Discusses the more effective time-based, interactive, and synchronized media types that have become viable with technological advancements.…

The Impact of Employment and Physical Activity on Academic Performance

ERIC Educational Resources Information Center

Andreopoulos, Giuliana Campanelli; Antoniou, Eliana; Panayides, Alexandros; Vassiliou, Evros

2008-01-01

Over the last twenty years, many contributions appeared on the relationship between working during school and academic performance using both quantitative and qualitative research methods. The obvious assumption is that a full time working student will show a lower academic performance relatively to a part time working student or a full time…

Effect of training frequency on the learning curve on the da Vinci Skills Simulator.

PubMed

Walliczek, Ute; Förtsch, Arne; Dworschak, Philipp; Teymoortash, Afshin; Mandapathil, Magis; Werner, Jochen; Güldner, Christian

2016-04-01

The purpose of this study was to evaluate the effect of training on the performance outcome with the da Vinci Skills Simulator. Forty novices were enrolled in a prospective training curriculum. Participants were separated into 2 groups. Group 1 performed 4 training sessions and group 2 had 2 training sessions over a 4-week period. Five exercises were performed 3 times consecutively. On the last training day, a new exercise was added. A significant skills gain from the first to the final practice day in overall performance, time to complete, and economy of motion was seen for both groups. Group 1 had a significantly better outcome in overall performance, time to complete, and economy of motion in all exercises. There was no significant difference found regarding the new exercise in group 1 versus group 2 in nearly all parameters. Longer time distances between training sessions are assumed to play a secondary role, whereas total repetition frequency is crucial for improvement of technical performance. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1762-E1769, 2016. © 2015 Wiley Periodicals, Inc.

Comparison of visual and emotional continuous performance test related to sequence of presentation, gender and age.

PubMed

Markovska-Simoska, S; Pop-Jordanova, N

2009-07-01

(Full text is available at http://www.manu.edu.mk/prilozi). Continous Performance Tests (CPTs) form a group of paradigms for the evaluation of attention and, to a lesser degree, the response inhibition (or disinhibition) component of executive control. The object of this study was to compare performance on a CPT using both visual and emotional tasks in 46 normal adult subjects. In particular, it was to examine the effects of the type of task (VCPT or ECPT), sequence of presentation, and gender/age influence on performance as measured errors of omission, errors of commission, reaction time and variation of reaction time. From the results we can assume that there are significantly worse performance parameters for ECPT than VCPT tasks, with a probable explanation of the influence of emotional stimuli on attention and information-processing and no significant effect of order of presentation and gender on performance. Significant differences with more omission errors for older groups were obtained, showing better attention in younger subjects. Key words: VCPT, ECPT, omission errors, commission errors, reaction time, variation of reaction time, normal adults.

Time-on-task decrements in "steer clear" performance of patients with sleep apnea and narcolepsy

NASA Technical Reports Server (NTRS)

Findley, L. J.; Suratt, P. M.; Dinges, D. F.

1999-01-01

Loss of attention with time-on-task reflects the increasing instability of the waking state during performance in experimentally induced sleepiness. To determine whether patients with disorders of excessive sleepiness also displayed time-on-task decrements indicative of wake state instability, visual sustained attention performance on "Steer Clear," a computerized simple RT driving simulation task, was compared among 31 patients with untreated sleep apnea, 16 patients with narcolepsy, and 14 healthy control subjects. Vigilance decrement functions were generated by analyzing the number of collisions in each of six four-minute periods of Steer Clear task performance in a mixed-model analysis of variance and linear regression equations. As expected, patients had more Steer Clear collisions than control subjects (p=0.006). However, the inter-subject variability in errors among the narcoleptic patients was four-fold that of the apnea patients, and 100-fold that of the controls volunteers; the variance in errors among untreated apnea patients was 27-times that of controls. The results of transformed collision data revealed main effects for group (p=0.006), time-on-task (p=0.001), and a significant interaction (p=0.022). Control subjects showed no clear evidence of increasing collision errors with time-on-task (adjusted R2=0.22), while apnea patients showed a trend toward vigilance decrement (adjusted R2=0.42, p=0.097), and narcolepsy patients evidenced a robust linear vigilance decrement (adjusted R2=0.87, p=0.004). The association of disorders of excessive somnolence with escalating time-on-task decrements makes it imperative that when assessment of neurobehavioral performance is conducted in patients, it involves task durations and analyses that will evaluate the underlying vulnerability of potentially sleepy patients to decrements over time in tasks that require sustained attention and timely responses, both of which are key components in safe driving performance.

A little elastic for a better performance: kinesiotaping of the motor effector modulates neural mechanisms for rhythmic movements

PubMed Central

Bravi, Riccardo; Quarta, Eros; Cohen, Erez J.; Gottard, Anna; Minciacchi, Diego

2014-01-01

A rhythmic motor performance is brought about by an integration of timing information with movements. Investigations on the millisecond time scale distinguish two forms of time control, event-based timing and emergent timing. While event-based timing asserts the existence of a central internal timekeeper for the control of repetitive movements, the emergent timing perspective claims that timing emerges from dynamic control of nontemporal movements parameters. We have recently demonstrated that the precision of an isochronous performance, defined as performance of repeated movements having a uniform duration, was insensible to auditory stimuli of various characteristics (Bravi et al., 2014). Such finding has led us to investigate whether the application of an elastic therapeutic tape (Kinesio® Tex taping; KTT) used for treating athletic injuries and a variety of physical disorders, is able to reduce the timing variability of repetitive rhythmic movement. Young healthy subjects, tested with and without KTT, have participated in sessions in which sets of repeated isochronous wrist's flexion-extensions (IWFEs) were performed under various auditory conditions and during their recall. Kinematics was recorded and temporal parameters were extracted and analyzed. Our results show that the application of KTT decreases the variability of rhythmic movements by a 2-fold effect: on the one hand KTT provides extra proprioceptive information activating cutaneous mechanoreceptors, on the other KTT biases toward the emergent timing thus modulating the processes for rhythmic movements. Therefore, KTT appears able to render movements less audio dependent by relieving, at least partially, the central structures from time control and making available more resources for an augmented performance. PMID:25309355

An Approach to Integrate a Space-Time GIS Data Model with High Performance Computers

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

Wang, Dali; Zhao, Ziliang; Shaw, Shih-Lung

2011-01-01

In this paper, we describe an approach to integrate a Space-Time GIS data model on a high performance computing platform. The Space-Time GIS data model has been developed on a desktop computing environment. We use the Space-Time GIS data model to generate GIS module, which organizes a series of remote sensing data. We are in the process of porting the GIS module into an HPC environment, in which the GIS modules handle large dataset directly via parallel file system. Although it is an ongoing project, authors hope this effort can inspire further discussions on the integration of GIS on highmore » performance computing platforms.« less

GOTHIC: Gravitational oct-tree code accelerated by hierarchical time step controlling

NASA Astrophysics Data System (ADS)

Miki, Yohei; Umemura, Masayuki

2017-04-01

The tree method is a widely implemented algorithm for collisionless N-body simulations in astrophysics well suited for GPU(s). Adopting hierarchical time stepping can accelerate N-body simulations; however, it is infrequently implemented and its potential remains untested in GPU implementations. We have developed a Gravitational Oct-Tree code accelerated by HIerarchical time step Controlling named GOTHIC, which adopts both the tree method and the hierarchical time step. The code adopts some adaptive optimizations by monitoring the execution time of each function on-the-fly and minimizes the time-to-solution by balancing the measured time of multiple functions. Results of performance measurements with realistic particle distribution performed on NVIDIA Tesla M2090, K20X, and GeForce GTX TITAN X, which are representative GPUs of the Fermi, Kepler, and Maxwell generation of GPUs, show that the hierarchical time step achieves a speedup by a factor of around 3-5 times compared to the shared time step. The measured elapsed time per step of GOTHIC is 0.30 s or 0.44 s on GTX TITAN X when the particle distribution represents the Andromeda galaxy or the NFW sphere, respectively, with 224 = 16,777,216 particles. The averaged performance of the code corresponds to 10-30% of the theoretical single precision peak performance of the GPU.

Change of search time and non-search time in X-ray baggage screening due to training.

PubMed

Koller, Saskia M; Drury, Colin G; Schwaninger, Adrian

2009-06-01

As found in studies of aircraft structural inspection, the time used for judging if a part of an aircraft shows tiny cracks is composed of search time, used for actively scanning, and non-search time, used for matching and decision while fixating a region of interest (Drury et al. 1997). These findings can be applied to detection of threats by X-ray screening of passenger bags at airports. To investigate whether search time and non-search time change when an experienced screener is given additional training in recognising threat objects in passenger bags, data from a European airport were analysed. A comparison of detection performance and reaction time between two large groups of screeners, one trained for 6 months, shows a large impact of training on overall performance and on both search and non-search components of the task. There was also a small but consistent decline in performance measures with screener age. This study shows a way to localise the effect of training on threat detection performance for aviation security screening. Analysis of the time needed for screening each passenger bag showed that training had a significant effect, particularly on the non-search part of the searching process (i.e. identification, recognition, decision, response execution, etc.).

Prime Time Light Exposures Do Not Seem to Improve Maximal Physical Performance in Male Elite Athletes, but Enhance End-Spurt Performance.

PubMed

Knaier, Raphael; Schäfer, Juliane; Rossmeissl, Anja; Klenk, Christopher; Hanssen, Henner; Höchsmann, Christoph; Cajochen, Christian; Schmidt-Trucksäss, Arno

2017-01-01

Many sports competitions take place during television prime time, a time of the day when many athletes have already exceeded their time of peak performance. We assessed the effect of different light exposure modalities on physical performance and melatonin levels in athletes during prime time. Seventy-two young, male elite athletes with a median (interquartile range) age of 23 (21; 29) years and maximum oxygen uptake (VO2max) of 63 (58; 66) ml/kg/min were randomly assigned to three different light exposure groups: bright light (BRIGHT), blue monochromatic light (BLUE), and control light (CONTROL). Each light exposure lasted 60 min and was scheduled to start 17 h after each individual's midpoint of sleep (median time: 9:17 pm). Immediately after light exposure, a 12-min time trial was performed on a bicycle ergometer. The test supervisor and participants were blinded to the light condition each participant was exposed to. The median received light intensities and peak wavelengths (photopic lx/nm) measured at eye level were 1319/545 in BRIGHT, 203/469 in BLUE, and 115/545 in CONTROL. In a multivariate analysis adjusted for individual VO2max, total work performed in 12 min did not significantly differ between the three groups. The amount of exposure to non-image forming light was positively associated with the performance gain during the time trial, defined as the ratio of the work performed in the first and last minute of the time trial, and with stronger melatonin suppression. Specifically, a tenfold increase in the exposure to melanopic light was associated with a performance gain of 8.0% (95% confidence interval: 2.6, 13.3; P = 0.004) and a melatonin decrease of -0.9 pg/ml (95% confidence interval: -1.5, -0.3; P = 0.006). Exposure to bright or blue light did not significantly improve maximum cycling performance in a 12-min all-out time trial. However, it is noteworthy that the estimated difference of 4.1 kJ between BRIGHT and CONTROL might represent an important performance advantage justifying further studies. In conclusion, we report novel evidence that evening light exposure, which strongly impacts the human circadian timing system, enables elite athletes to better maintain performance across a 12-min cycling time trial.

Prime Time Light Exposures Do Not Seem to Improve Maximal Physical Performance in Male Elite Athletes, but Enhance End-Spurt Performance

PubMed Central

Knaier, Raphael; Schäfer, Juliane; Rossmeissl, Anja; Klenk, Christopher; Hanssen, Henner; Höchsmann, Christoph; Cajochen, Christian; Schmidt-Trucksäss, Arno

2017-01-01

Many sports competitions take place during television prime time, a time of the day when many athletes have already exceeded their time of peak performance. We assessed the effect of different light exposure modalities on physical performance and melatonin levels in athletes during prime time. Seventy-two young, male elite athletes with a median (interquartile range) age of 23 (21; 29) years and maximum oxygen uptake (VO2max) of 63 (58; 66) ml/kg/min were randomly assigned to three different light exposure groups: bright light (BRIGHT), blue monochromatic light (BLUE), and control light (CONTROL). Each light exposure lasted 60 min and was scheduled to start 17 h after each individual's midpoint of sleep (median time: 9:17 pm). Immediately after light exposure, a 12-min time trial was performed on a bicycle ergometer. The test supervisor and participants were blinded to the light condition each participant was exposed to. The median received light intensities and peak wavelengths (photopic lx/nm) measured at eye level were 1319/545 in BRIGHT, 203/469 in BLUE, and 115/545 in CONTROL. In a multivariate analysis adjusted for individual VO2max, total work performed in 12 min did not significantly differ between the three groups. The amount of exposure to non-image forming light was positively associated with the performance gain during the time trial, defined as the ratio of the work performed in the first and last minute of the time trial, and with stronger melatonin suppression. Specifically, a tenfold increase in the exposure to melanopic light was associated with a performance gain of 8.0% (95% confidence interval: 2.6, 13.3; P = 0.004) and a melatonin decrease of −0.9 pg/ml (95% confidence interval: −1.5, −0.3; P = 0.006). Exposure to bright or blue light did not significantly improve maximum cycling performance in a 12-min all-out time trial. However, it is noteworthy that the estimated difference of 4.1 kJ between BRIGHT and CONTROL might represent an important performance advantage justifying further studies. In conclusion, we report novel evidence that evening light exposure, which strongly impacts the human circadian timing system, enables elite athletes to better maintain performance across a 12-min cycling time trial. PMID:28507521

The influence of time management skill on the curvilinear relationship between organizational citizenship behavior and task performance.

PubMed

Rapp, Adam A; Bachrach, Daniel G; Rapp, Tammy L

2013-07-01

In this research we integrate resource allocation and social exchange perspectives to build and test theory focusing on the moderating role of time management skill in the nonmonotonic relationship between organizational citizenship behavior (OCB) and task performance. Results from matching survey data collected from 212 employees and 41 supervisors and from task performance metrics collected several months later indicate that the curvilinear association between OCB and task performance is significantly moderated by employees' time management skill. Implications for theory and practice are discussed. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Comparison of Ventilatory Measures and 20 km Time Trial Performance.

PubMed

Peveler, Willard W; Shew, Brandy; Johnson, Samantha; Sanders, Gabe; Kollock, Roger

2017-01-01

Performance threshold measures are used to predict cycling performance. Previous research has focused on long time trials (≥ 40 km) using power at ventilatory threshold and respiratory threshold to estimate time trial performance. As intensity greatly differs during shorter time trails applying findings from longer time trials may not be appropriate. The use of heart rate measures to determine 20 km time trial performance has yet to be examined. The purpose of this study was to determine the effectiveness of heart rate measures at ventilatory threshold (VE/VO 2 Plotted and VT determined by software) and respiratory threshold (RER of 0.95, 1.00, and 1.05) to predict 20 km time trial performance. Eighteen cyclists completed a VO 2max protocol and two 20 km time trials. Average heart rates from 20 km time trials were compared with heart rates from performance threshold measures (VT plotted, VT software, and an RER at 0.95, 1.00, and 1.05) using repeated measures ANOVA. Significance was set a priori at P ≤ 0.05. The only measure not found to be significantly different in relation to time trial performance was HR at an RER of 1.00 (166.61±12.70 bpm vs. 165.89 ± 9.56 bpm, p = .671). VT plotting and VT determined by software were found to underestimate time trial performance by 3% and 8% respectively. From these findings it is recommended to use heart rate at a RER of 1.00 in order to determine 20 km time trial intensity.

Erroneous Knowledge of Results Affects Decision and Memory Processes on Timing Tasks

ERIC Educational Resources Information Center

Ryan, Lawrence J.; Fritz, Matthew S.

2007-01-01

On mental timing tasks, erroneous knowledge of results (KR) leads to incorrect performance accompanied by the subjective judgment of accurate performance. Using the start-stop technique (an analogue of the peak interval procedure) with both reproduction and production timing tasks, the authors analyze what processes erroneous KR alters. KR…

Timing performance of a self-cancelling turn-signal mechanism in motorcycles based on the ATMega328P microcontroller

NASA Astrophysics Data System (ADS)

Nurbuwat, Adzin Kondo; Eryandi, Kholid Yusuf; Estriyanto, Yuyun; Widiastuti, Indah; Pambudi, Nugroho Agung

2018-02-01

The objective of this study is to measure the time performance of a self-cancelling turn signal mechanism based on the In this study the performance of self-cancelling turn signal based on ATMega328P microcontroller is measured at low speed and high speed treatment on motorcycles commonly used in Indonesia. Time performance measurements were made by comparing the self-cancelling turn signal based on ATMega328P microcontroller with standard motor turn time. Measurements of time at low speed treatment were performed at a speed range of 15 km / h, 20 km / h, 25 km / h on the U-turn test trajectory. The angle of the turning angle of the potentiometer is determined at 3°. The limit of steering wheel turning angle at the potentiometer is set at 3°. For high-speed treatment is 30 km / h, 40 km / h, 50km / h, and 60 km / h, on the L-turn test track with a tilt angle (roll angle) read by the L3G4200D gyroscope sensor. Each speed test is repeated 3 replications. Standard time is a reference for self-cancelling turn signal performance. The standard time obtained is 15.68 s, 11.96 s, 9.34 s at low speed and 4.63 s, 4.06 s, 3.61 s, 3.13 s at high speed. The time test of self-cancelling turn signal shows 16.10 s, 12.42 s, 10.24 s at the low speed and 5.18, 4.51, 3.73, 3.21 at the high speed. At a speed of 15 km / h occurs the instability of motion turns motorcycle so that testing is more difficult. Small time deviations indicate the tool works well. The largest time deviation value is 0.9 seconds at low speed and 0.55 seconds at high speed. The conclusion at low velocity of the highest deviation value occurred at the speed of 25 km / h test due to the movement of slope with inclination has started to happen which resulted in slow reading of steering movement. At higher speeds the time slows down due to rapid sensor readings on the tilt when turning fast at ever higher speeds. The timing performance of self-cancelling turn signal decreases as the motorcycle turning characteristics move from the turn using the steering angle to using a tilt angle based on speed, or vice versa.

Impact of lean six sigma process improvement methodology on cardiac catheterization laboratory efficiency.

PubMed

Agarwal, Shikhar; Gallo, Justin J; Parashar, Akhil; Agarwal, Kanika K; Ellis, Stephen G; Khot, Umesh N; Spooner, Robin; Murat Tuzcu, Emin; Kapadia, Samir R

2016-03-01

Operational inefficiencies are ubiquitous in several healthcare processes. To improve the operational efficiency of our catheterization laboratory (Cath Lab), we implemented a lean six sigma process improvement initiative, starting in June 2010. We aimed to study the impact of lean six sigma implementation on improving the efficiency and the patient throughput in our Cath Lab. All elective and urgent cardiac catheterization procedures including diagnostic coronary angiography, percutaneous coronary interventions, structural interventions and peripheral interventions performed between June 2009 and December 2012 were included in the study. Performance metrics utilized for analysis included turn-time, physician downtime, on-time patient arrival, on-time physician arrival, on-time start and manual sheath-pulls inside the Cath Lab. After implementation of lean six sigma in the Cath Lab, we observed a significant improvement in turn-time, physician downtime, on-time patient arrival, on-time physician arrival, on-time start as well as sheath-pulls inside the Cath Lab. The percentage of cases with optimal turn-time increased from 43.6% in 2009 to 56.6% in 2012 (p-trend<0.001). Similarly, the percentage of cases with an aggregate on-time start increased from 41.7% in 2009 to 62.8% in 2012 (p-trend<0.001). In addition, the percentage of manual sheath-pulls performed in the Cath Lab decreased from 60.7% in 2009 to 22.7% in 2012 (p-trend<0.001). The current longitudinal study illustrates the impact of successful implementation of a well-known process improvement initiative, lean six sigma, on improving and sustaining efficiency of our Cath Lab operation. After the successful implementation of this continuous quality improvement initiative, there was a significant improvement in the selected performance metrics namely turn-time, physician downtime, on-time patient arrival, on-time physician arrival, on-time start as well as sheath-pulls inside the Cath Lab. Copyright © 2016 Elsevier Inc. All rights reserved.

The effects of partial sleep restriction and altered sleep timing on olfactory performance.

PubMed

McNeil, J; Forest, G; Hintze, L J; Brunet, J-F; Doucet, É

2017-12-01

Olfaction can increase the drive to eat and may partially explain the consistent increases in energy intake (EI) following sleep restriction. We investigated the effects of 50% sleep restriction with altered sleep timing on olfactory performance. We also evaluated whether changes (Δ) in olfactory performance were associated with Δ24 h EI. Twelve men and six women (age: 23±4 years; BMI: 23±3 kg/m 2 ) completed three randomized cross-over conditions: habitual sleep duration, 50% sleep restriction with advanced wake-time, and 50% sleep restriction with delayed bedtime. Sleep was measured in-laboratory (polysomnography). Olfactory performance ('sniffin sticks') and 24 h EI (food menu) were evaluated the next day. A trend for a significant condition*sex interaction was noted for threshold-discrimination-identification (TDI) scores (P=0.09); TDI scores were lowest in women and highest in men, following sleep restriction with advanced wake-time. Δolfactory performance were not associated with Δ24 h EI. The impact of sleep restriction on olfactory performance may differ between sexes. Changes in olfactory performance were not associated with changes in 24 h EI. Studies investigating prolonged effects of sleep loss on the relationship between olfactory performance with EI are needed.

The power of "we": effects of psychological collectivism on team performance over time.

PubMed

Dierdorff, Erich C; Bell, Suzanne T; Belohlav, James A

2011-03-01

We examined the influences of different facets of psychological collectivism (Preference, Reliance, Concern, Norm Acceptance, and Goal Priority) on team functioning at 3 different performance depictions: initial team performance, end-state team performance, and team performance change over time. We also tested the extent to which team-member exchange moderated the relationships between facets of psychological collectivism and performance change over time. Results from multilevel growth modeling of 66 teams (N = 264) engaged in a business simulation revealed differential effects across facets of psychological collectivism and across different performance measurements. Whereas facets concerned with affiliation (Preference and Concern) were positively related to initial team performance, reliance was negatively related to initial team performance. Goal Priority was a strong predictor of end-state performance. Team-member exchange moderated the relationship between performance change and 3 of the 5 facets of psychological collectivism (Preference, Reliance, Norm Acceptance). Implications for team composition and team training are discussed. PsycINFO Database Record (c) 2011 APA, all rights reserved.

Pathophysiological Distortions in Time Perception and Timed Performance

ERIC Educational Resources Information Center

Allman, Melissa J.; Meck, Warren H.

2012-01-01

Distortions in time perception and timed performance are presented by a number of different neurological and psychiatric conditions (e.g. Parkinson's disease, schizophrenia, attention deficit hyperactivity disorder and autism). As a consequence, the primary focus of this review is on factors that define or produce systematic changes in the…

Long-range correlation properties in timing of skilled piano performance: the influence of auditory feedback and deep brain stimulation.

PubMed

Herrojo Ruiz, María; Hong, Sang Bin; Hennig, Holger; Altenmüller, Eckart; Kühn, Andrea A

2014-01-01

Unintentional timing deviations during musical performance can be conceived of as timing errors. However, recent research on humanizing computer-generated music has demonstrated that timing fluctuations that exhibit long-range temporal correlations (LRTC) are preferred by human listeners. This preference can be accounted for by the ubiquitous presence of LRTC in human tapping and rhythmic performances. Interestingly, the manifestation of LRTC in tapping behavior seems to be driven in a subject-specific manner by the LRTC properties of resting-state background cortical oscillatory activity. In this framework, the current study aimed to investigate whether propagation of timing deviations during the skilled, memorized piano performance (without metronome) of 17 professional pianists exhibits LRTC and whether the structure of the correlations is influenced by the presence or absence of auditory feedback. As an additional goal, we set out to investigate the influence of altering the dynamics along the cortico-basal-ganglia-thalamo-cortical network via deep brain stimulation (DBS) on the LRTC properties of musical performance. Specifically, we investigated temporal deviations during the skilled piano performance of a non-professional pianist who was treated with subthalamic-deep brain stimulation (STN-DBS) due to severe Parkinson's disease, with predominant tremor affecting his right upper extremity. In the tremor-affected right hand, the timing fluctuations of the performance exhibited random correlations with DBS OFF. By contrast, DBS restored long-range dependency in the temporal fluctuations, corresponding with the general motor improvement on DBS. Overall, the present investigations demonstrate the presence of LRTC in skilled piano performances, indicating that unintentional temporal deviations are correlated over a wide range of time scales. This phenomenon is stable after removal of the auditory feedback, but is altered by STN-DBS, which suggests that cortico-basal ganglia-thalamocortical circuits play a role in the modulation of the serial correlations of timing fluctuations exhibited in skilled musical performance.

Airplane takeoff and landing performance monitoring system

NASA Technical Reports Server (NTRS)

Middleton, David B. (Inventor); Srivatsan, Raghavachari (Inventor); Person, Lee H. (Inventor)

1989-01-01

The invention is a real-time takeoff and landing performance monitoring system which provides the pilot with graphic and metric information to assist in decisions related to achieving rotation speed (V sub R) within the safe zone of the runway or stopping the aircraft on the runway after landing or take off abort. The system processes information in two segments: a pretakeoff segment and a real-time segment. One-time inputs of ambient conditions and airplane configuration information are used in the pretakeoff segment to generate scheduled performance data. The real-time segment uses the scheduled performance data, runway length data and transducer measured parameters to monitor the performance of the airplane throughout the takeoff roll. An important feature of this segment is that it updates the estimated runway rolling friction coefficient. Airplane performance predictions also reflect changes in headwind occurring as the takeoff roll progresses. The system displays the position of the airplane on the runway, indicating runway used and runway available, summarizes the critical information into a situation advisory flag, flags engine failures and off-nominal acceleration performance, and indicates where on the runway particular events such as decision speed (V sub 1), rotation speed (V sub R) and expected stop points will occur based on actual or predicted performance. The display also indicates airspeed, wind vector, engine pressure ratios, second segment climb speed, and balanced field length (BFL). The system detects performance deficiencies by comparing the airplane's present performance with a predicted nominal performance based upon the given conditions.

HPC on Competitive Cloud Resources

NASA Astrophysics Data System (ADS)

Bientinesi, Paolo; Iakymchuk, Roman; Napper, Jeff

Computing as a utility has reached the mainstream. Scientists can now easily rent time on large commercial clusters that can be expanded and reduced on-demand in real-time. However, current commercial cloud computing performance falls short of systems specifically designed for scientific applications. Scientific computing needs are quite different from those of the web applications that have been the focus of cloud computing vendors. In this chapter we demonstrate through empirical evaluation the computational efficiency of high-performance numerical applications in a commercial cloud environment when resources are shared under high contention. Using the Linpack benchmark as a case study, we show that cache utilization becomes highly unpredictable and similarly affects computation time. For some problems, not only is it more efficient to underutilize resources, but the solution can be reached sooner in realtime (wall-time). We also show that the smallest, cheapest (64-bit) instance on the studied environment is the best for price to performance ration. In light of the high-contention we witness, we believe that alternative definitions of efficiency for commercial cloud environments should be introduced where strong performance guarantees do not exist. Concepts like average, expected performance and execution time, expected cost to completion, and variance measures--traditionally ignored in the high-performance computing context--now should complement or even substitute the standard definitions of efficiency.

Interpreting the Need for Initial Support to Perform Tandem Stance Tests of Balance

PubMed Central

Brach, Jennifer S.; Perera, Subashan; Wert, David M.; VanSwearingen, Jessie M.; Studenski, Stephanie A.

2012-01-01

Background Geriatric rehabilitation reimbursement increasingly requires documented deficits on standardized measures. Tandem stance performance can characterize balance, but protocols are not standardized. Objective The purpose of this study was to explore the impact of: (1) initial support to stabilize in position and (2) maximum hold time on tandem stance tests of balance in older adults. Design A cross-sectional secondary analysis of observational cohort data was conducted. Methods One hundred seventeen community-dwelling older adults (71% female, 12% black) were assigned to 1 of 3 groups based on the need for initial support to perform tandem stance: (1) unable even with support, (2) able only with support, and (3) able without support. The able without support group was further stratified on hold time in seconds: (1) <10 (low), (2) 10 to 29, (medium), and (3) 30 (high). Groups were compared on primary outcomes (gait speed, Timed “Up & Go” Test performance, and balance confidence) using analysis of variance. Results Twelve participants were unable to perform tandem stance, 14 performed tandem stance only with support, and 91 performed tandem stance without support. Compared with the able without support group, the able with support group had statistically or clinically worse performance and balance confidence. No significant differences were found between the able with support group and the unable even with support group on these same measures. Extending the hold time to 30 seconds in a protocol without initial support eliminated ceiling effects for 16% of the study sample. Limitations Small comparison groups, use of a secondary analysis, and lack of generalizability of results were limitations of the study. Conclusions Requiring initial support to stabilize in tandem stance appears to reflect meaningful deficits in balance-related mobility measures, so failing to consider support may inflate balance estimates and confound hold time comparisons. Additionally, 10-second maximum hold times limit discrimination of balance in adults with a higher level of function. For community-dwelling older adults, we recommend timing for at least 30 seconds and documenting initial support for consideration when interpreting performance. PMID:22745198

What keeps family physicians busy in Portugal? A multicentre observational study of work other than direct patient contacts

PubMed Central

Granja, Mónica; Ponte, Carla; Cavadas, Luís Filipe

2014-01-01

Objectives To quantify the time spent by family physicians (FP) on tasks other than direct patient contact, to evaluate job satisfaction, to analyse the association between time spent on tasks and physician characteristics, the association between the number of tasks performed and physician characteristics and the association between time spent on tasks and job satisfaction. Design Cross-sectional, using time-and-motion techniques. Two workdays were documented by direct observation. A significance level of 0.05 was adopted. Setting Multicentric in 104 Portuguese family practices. Participants A convenience sample of FP, with lists of over 1000 patients, teaching senior medical students and first-year family medicine residents in 2012, was obtained. Of the 217 FP invited to participate, 155 completed the study. Main outcomes measured Time spent on tasks other than direct patient contact and on the performance of more than one task simultaneously, the number of direct patient contacts in the office, the number of indirect patient contacts, job satisfaction, demographic and professional characteristics associated with time spent on tasks and the number of different tasks performed, and the association between time spent on tasks and job satisfaction. Results FP (n=155) spent a mean of 143.6 min/day (95% CI 135.2 to 152.0) performing tasks such as prescription refills, teaching, meetings, management and communication with other professionals (33.4% of their workload). FP with larger patient lists spent less time on these tasks (p=0.002). Older FP (p=0.021) and those with larger lists (p=0.011) performed fewer tasks. The mean job satisfaction score was 3.5 (out of 5). No association was found between job satisfaction and time spent on tasks. Conclusions FP spent one-third of their workday in coordinating care, teaching and managing. Time devoted to these tasks decreases with increasing list size and physician age. PMID:24934208

Effect of visual media use on school performance: a prospective study.

PubMed

Sharif, Iman; Wills, Thomas A; Sargent, James D

2010-01-01

To identify mechanisms for the impact of visual media use on adolescents' school performance. We conducted a 24-month, four-wave longitudinal telephone study of a national sample of 6,486 youth aged 10 to 14 years. Exposure measures: latent construct for screen exposure time (weekday time spent viewing television/playing videogames, presence of television in bedroom) and variables for movie content (proportion of PG-13 and R movies viewed). self- and parent reports of grades in school. Effects of media exposures on change in school performance between baseline and 24 months were assessed using structural equation modeling. Information about hypothesized mediators (substance use, sensation seeking, and school problem behavior) was obtained at baseline and at the 16-month follow-up. Adjusted for baseline school performance, baseline levels of mediators, and a range of covariates, both screen exposure time and media content had adverse effects on change in school performance. Screen exposure had an indirect effect on poor school performance through increased sensation seeking. Viewing more PG-13 and R-rated movies had indirect effects on poor school performance mediated through increases in substance use and sensation seeking. R-rated viewing also had an indirect effect on poor school performance through increased school behavior problems. The effect sizes of exposure time and content on the intermediate variables and ultimately on school performance were similar to those for previously recognized determinants of these mediators, including household income, parenting style, and adolescents' self-control. These aspects of visual media use adversely affect school performance by increasing sensation seeking, substance use, and school problem behavior. Copyright 2010 Society for Adolescent Medicine. Published by Elsevier Inc. All rights reserved.

Effect of Visual Media Use on School Performance: A Prospective Study1

PubMed Central

Sharif, Iman; Wills, Thomas A.; Sargent, James D.

2009-01-01

Purpose To identify mechanisms for the impact of visual media use on adolescents' school performance. Methods We conducted a 24-month, four-wave longitudinal telephone study of a national sample of 6,486 youth aged 10-14 years. Exposure Measures: Latent construct for screen exposure time (weekday time spent viewing television/playing videogames, presence of television in bedroom) and variables for movie content (proportion of PG13 and R movies viewed). Outcome Measure: Self and parent reports of grades in school. Effects of media exposures on change in school performance between baseline and 24 months were assessed using structural equation modeling. Information about hypothesized mediators (substance use, sensation-seeking, and school problem behavior) was obtained at baseline and at the16-month follow-up. Results Adjusted for baseline school performance, baseline levels of mediators, and a range of covariates, both screen exposure time and media content had adverse effects on change in school performance. Screen exposure had an indirect effect on poor school performance through increased sensation-seeking. Viewing more PG-13 and R-rated movies had indirect effects on poor school performance mediated through increases in substance use and sensation-seeking. R-rated viewing also had an indirect effect on poor school performance through increased school behavior problems. The effect sizes of exposure time and content on the intermediate variables and ultimately on school performance were similar to those for previously recognized determinants of these mediators – including household income, parenting style, and adolescents' self-control. Conclusions These aspects of visual media use adversely affect school performance by increasing sensation-seeking, substance use and school problem behavior. PMID:20123258

Programmable neural processing on a smartdust for brain-computer interfaces.

PubMed

Yuwen Sun; Shimeng Huang; Oresko, Joseph J; Cheng, Allen C

2010-10-01

Brain-computer interfaces (BCIs) offer tremendous promise for improving the quality of life for disabled individuals. BCIs use spike sorting to identify the source of each neural firing. To date, spike sorting has been performed by either using off-chip analysis, which requires a wired connection penetrating the skull to a bulky external power/processing unit, or via custom application-specific integrated circuits that lack the programmability to perform different algorithms and upgrades. In this research, we propose and test the feasibility of performing on-chip, real-time spike sorting on a programmable smartdust, including feature extraction, classification, compression, and wireless transmission. A detailed power/performance tradeoff analysis using DVFS is presented. Our experimental results show that the execution time and power density meet the requirements to perform real-time spike sorting and wireless transmission on a single neural channel.

The Association of Sitting Time With Sarcopenia Status and Physical Performance at Baseline and 18-Month Follow-Up in the Residential Aged Care Setting.

PubMed

Reid, Natasha; Keogh, Justin W; Swinton, Paul; Gardiner, Paul A; Henwood, Timothy R

2018-06-18

This study investigated the association of sitting time with sarcopenia and physical performance in residential aged care residents at baseline and 18-month follow-up. Measures included the International Physical Activity Questionnaire (sitting time), European Working Group definition of sarcopenia, and the short physical performance battery (physical performance). Logistic regression and linear regression analyses were used to investigate associations. For each hour of sitting, the unadjusted odds ratio of sarcopenia was 1.16 (95% confidence interval [0.98, 1.37]). Linear regression showed that each hour of sitting was significantly associated with a 0.2-unit lower score for performance. Associations of baseline sitting with follow-up sarcopenia status and performance were nonsignificant. Cross-sectionally, increased sitting time in residential aged care may be detrimentally associated with sarcopenia and physical performance. Based on current reablement models of care, future studies should investigate if reducing sedentary time improves performance among adults in end of life care.

Evaluation of Augmented Reality Feedback in Surgical Training Environment.

PubMed

Zahiri, Mohsen; Nelson, Carl A; Oleynikov, Dmitry; Siu, Ka-Chun

2018-02-01

Providing computer-based laparoscopic surgical training has several advantages that enhance the training process. Self-evaluation and real-time performance feedback are 2 of these advantages, which avoid dependency of trainees on expert feedback. The goal of this study was to investigate the use of a visual time indicator as real-time feedback correlated with the laparoscopic surgical training. Twenty novices participated in this study working with (and without) different presentations of time indicators. They performed a standard peg transfer task, and their completion times and muscle activity were recorded and compared. Also of interest was whether the use of this type of feedback induced any side effect in terms of motivation or muscle fatigue. Of the 20 participants, 15 (75%) preferred using a time indicator in the training process rather than having no feedback. However, time to task completion showed no significant difference in performance with the time indicator; furthermore, no significant differences in muscle activity or muscle fatigue were detected with/without time feedback. The absence of significant difference between task performance with/without time feedback shows that using visual real-time feedback can be included in surgical training based on user preference. Trainees may benefit from this type of feedback in the form of increased motivation. The extent to which this can influence training frequency leading to performance improvement is a question for further study.

The Effects of Different Types of Environmental Noise on Academic Performance and Perceived Task Difficulty in Adolescents With ADHD.

PubMed

Batho, Lauren P; Martinussen, Rhonda; Wiener, Judith

2015-07-28

To examine the effects of environmental noises (speech and white noise) relative to a no noise control condition on the performance and difficulty ratings of youth with ADHD (N = 52) on academic tasks. Reading performance was measured by an oral retell (reading accuracy) and the time spent reading. Writing performance was measured through the proportion of correct writing sequences (writing accuracy) and the total words written on an essay. Participants in the white noise condition took less time to read the passage and wrote more words on the essay compared with participants in the other conditions, though white noise did not improve academic accuracy. The participants in the babble condition rated the tasks as most difficult. Although white noise appears to improve reading time and writing fluency, the findings suggest that white noise does not improve performance accuracy. Educational implications are discussed. © 2015 SAGE Publications.

A performance analysis method for distributed real-time robotic systems: A case study of remote teleoperation

NASA Technical Reports Server (NTRS)

Lefebvre, D. R.; Sanderson, A. C.

1994-01-01

Robot coordination and control systems for remote teleoperation applications are by necessity implemented on distributed computers. Modeling and performance analysis of these distributed robotic systems is difficult, but important for economic system design. Performance analysis methods originally developed for conventional distributed computer systems are often unsatisfactory for evaluating real-time systems. The paper introduces a formal model of distributed robotic control systems; and a performance analysis method, based on scheduling theory, which can handle concurrent hard-real-time response specifications. Use of the method is illustrated by a case of remote teleoperation which assesses the effect of communication delays and the allocation of robot control functions on control system hardware requirements.

Impact of video game genre on surgical skills development: a feasibility study.

PubMed

de Araujo, Thiago Bozzi; Silveira, Filipe Rodrigues; Souza, Dante Lucas Santos; Strey, Yuri Thomé Machado; Flores, Cecilia Dias; Webster, Ronaldo Scholze

2016-03-01

The playing of video games (VGs) was previously shown to improve surgical skills. This is the first randomized, controlled study to assess the impact of VG genre on the development of basic surgical skills. Twenty first-year, surgically inexperienced medical students attended a practical course on surgical knots, suturing, and skin-flap technique. Later, they were randomized into four groups: control and/or nongaming (ContG), first-person-shooter game (ShotG), racing game (RaceG), and surgery game (SurgG). All participants had 3 wk of Nintendo Wii training. Surgical and VG performances were assessed by two independent, blinded surgeons who evaluated basal performance (time 0) and performance after 1 wk (time 1) and 3 wk (time 2) of training. The training time of RaceG was longer than that of ShotG and SurgG (P = 0.045). Compared to SurgG and RaceG, VG scores for ShotG improved less between times 0 and 1 (P = 0.010) but more between times 1 and 2 (P = 0.004). Improvement in mean surgical performance scores versus time differed in each VG group (P = 0.011). At time 2, surgical performance scores were significantly higher in ShotG (P = 0.002) and SurgG (P = 0.022) than in ContG. The surgical performance scores of RaceG were not significantly different from the score achieved by ContG (P = 0.279). Different VG genres may differentially impact the development of surgical skills by medical students. More complex games seem to improve performance even if played less. Although further studies are needed, surgery-related VGs with sufficient complexity and playability could be a feasible adjuvant to improving surgical skills. Copyright © 2016 Elsevier Inc. All rights reserved.

Increasing Recovery Time Between Injuries Improves Cognitive Outcome After Repetitive Mild Concussive Brain Injuries in Mice

PubMed Central

Zhang, Jimmy; Mannix, Rebekah; Whalen, Michael J.

2012-01-01

Abstract BACKGROUND: Although previous evidence suggests that the cognitive effects of concussions are cumulative, the effect of time interval between repeat concussions is largely unknown. OBJECTIVE: To determine the effect of time interval between repeat concussions on the cognitive function of mice. METHODS: We used a weight-drop model of concussion to subject anesthetized mice to 1, 3, 5, or 10 concussions, each a day apart. Additional mice were subjected to 5 concussions at varying time intervals: daily, weekly, and monthly. Morris water maze performance was measured 24 hours, 1 month, and 1 year after final injury. RESULTS: After 1 concussion, injured and sham-injured mice performed similarly in the Morris water maze. As the number of concussions increased, injured mice performed worse than sham-injured mice. Mice sustaining 5 concussions either 1 day or 1 week apart performed worse than sham-injured mice. When 5 concussions were delivered at 1-month time intervals, no difference in Morris water maze performance was observed between injured and sham-injured mice. After a 1-month recovery period, mice that sustained 5 concussions at daily and weekly time intervals continued to perform worse than sham-injured mice. One year after the final injury, mice sustaining 5 concussions at a daily time interval still performed worse than sham-injured mice. CONCLUSION: When delivered within a period of vulnerability, the cognitive effects of multiple concussions are cumulative, persistent, and may be permanent. Increasing the time interval between concussions attenuates the effects on cognition. When multiple concussions are sustained by mice daily, the effects on cognition are long term. PMID:22743360

A time scheduling model of logistics service supply chain based on the customer order decoupling point: a perspective from the constant service operation time.

PubMed

Liu, Weihua; Yang, Yi; Xu, Haitao; Liu, Xiaoyan; Wang, Yijia; Liang, Zhicheng

2014-01-01

In mass customization logistics service, reasonable scheduling of the logistics service supply chain (LSSC), especially time scheduling, is benefit to increase its competitiveness. Therefore, the effect of a customer order decoupling point (CODP) on the time scheduling performance should be considered. To minimize the total order operation cost of the LSSC, minimize the difference between the expected and actual time of completing the service orders, and maximize the satisfaction of functional logistics service providers, this study establishes an LSSC time scheduling model based on the CODP. Matlab 7.8 software is used in the numerical analysis for a specific example. Results show that the order completion time of the LSSC can be delayed or be ahead of schedule but cannot be infinitely advanced or infinitely delayed. Obtaining the optimal comprehensive performance can be effective if the expected order completion time is appropriately delayed. The increase in supply chain comprehensive performance caused by the increase in the relationship coefficient of logistics service integrator (LSI) is limited. The relative concern degree of LSI on cost and service delivery punctuality leads to not only changes in CODP but also to those in the scheduling performance of the LSSC.

A Time Scheduling Model of Logistics Service Supply Chain Based on the Customer Order Decoupling Point: A Perspective from the Constant Service Operation Time

PubMed Central

Yang, Yi; Xu, Haitao; Liu, Xiaoyan; Wang, Yijia; Liang, Zhicheng

2014-01-01

In mass customization logistics service, reasonable scheduling of the logistics service supply chain (LSSC), especially time scheduling, is benefit to increase its competitiveness. Therefore, the effect of a customer order decoupling point (CODP) on the time scheduling performance should be considered. To minimize the total order operation cost of the LSSC, minimize the difference between the expected and actual time of completing the service orders, and maximize the satisfaction of functional logistics service providers, this study establishes an LSSC time scheduling model based on the CODP. Matlab 7.8 software is used in the numerical analysis for a specific example. Results show that the order completion time of the LSSC can be delayed or be ahead of schedule but cannot be infinitely advanced or infinitely delayed. Obtaining the optimal comprehensive performance can be effective if the expected order completion time is appropriately delayed. The increase in supply chain comprehensive performance caused by the increase in the relationship coefficient of logistics service integrator (LSI) is limited. The relative concern degree of LSI on cost and service delivery punctuality leads to not only changes in CODP but also to those in the scheduling performance of the LSSC. PMID:24715818

High Performance Computing of Meshless Time Domain Method on Multi-GPU Cluster

NASA Astrophysics Data System (ADS)

Ikuno, Soichiro; Nakata, Susumu; Hirokawa, Yuta; Itoh, Taku

2015-01-01

High performance computing of Meshless Time Domain Method (MTDM) on multi-GPU using the supercomputer HA-PACS (Highly Accelerated Parallel Advanced system for Computational Sciences) at University of Tsukuba is investigated. Generally, the finite difference time domain (FDTD) method is adopted for the numerical simulation of the electromagnetic wave propagation phenomena. However, the numerical domain must be divided into rectangle meshes, and it is difficult to adopt the problem in a complexed domain to the method. On the other hand, MTDM can be easily adept to the problem because MTDM does not requires meshes. In the present study, we implement MTDM on multi-GPU cluster to speedup the method, and numerically investigate the performance of the method on multi-GPU cluster. To reduce the computation time, the communication time between the decomposed domain is hided below the perfect matched layer (PML) calculation procedure. The results of computation show that speedup of MTDM on 128 GPUs is 173 times faster than that of single CPU calculation.

Sleep restriction and degraded reaction-time performance in Figaro solo sailing races.

PubMed

Hurdiel, Rémy; Van Dongen, Hans P A; Aron, Christophe; McCauley, Peter; Jacolot, Laure; Theunynck, Denis

2014-01-01

In solo offshore sailing races like those of the Solitaire du Figaro, sleep must be obtained in multiple short bouts to maintain competitive performance and safety. Little is known about the amount of sleep restriction experienced at sea and the effects that fatigue from sleep loss have on sailors' performance. Therefore, we assessed sleep in sailors of yachts in the Figaro 2 Beneteau class during races and compared response times on a serial simple reaction-time test before and after races. Twelve men (professional sailors) recorded their sleep and measured their response times during one of the three single-handed races of 150, 300 and 350 nautical miles (nominally 24-50 h in duration). Total estimated sleep duration at sea indicated considerable sleep insufficiency. Response times were slower after races than before. The results suggest that professional sailors incur severe sleep loss and demonstrate marked performance impairment when competing in one- to two-day solo sailing races. Competitive performance could be improved by actively managing sleep during solo offshore sailing races.

Wisconsin Card Sorting Test performance over time in schizophrenia. Preliminary evidence from clinical follow-up and neuroleptic reduction studies.

PubMed

Seidman, L J; Pepple, J R; Faraone, S V; Kremen, W S; Cassens, G; McCarley, R W; Tsuang, M T

1991-10-01

Two groups of schizophrenic patients took the Wisconsin Card Sorting Test (WCST) in separate follow-up studies; a naturalistic clinical follow-up (n = 12, study 1) and a neuroleptic reduction study (n = 10, study 2). 11 of 22 subjects (50%) performed well on the task at one or both time points. In each study no group differences were found between time 1 and time 2 performance on three WCST variables. However, correlational analyses revealed considerable within-subject variation on the WCST in the study 1 sample, which was composed of younger and more acute patients than those in study 2. This variation was present despite within-subject stability on the WAIS-R Vocabulary and Block Design subtests. For the sample combined, a trend was found (p = 0.12) linking better WCST performance at either time period with higher WAIS-R Vocabulary scores. This intra-subject variability may reflect fluctuations in neuropsychological performance in schizophrenics who maintain the residual capacity to do the task. These findings highlight the importance of longitudinal studies of neuropsychological functioning in schizophrenia. Studies of larger samples are needed to confirm these initial results.

Comparison of success rates, learning curves, and inter-subject performance variability of robot-assisted and manual ultrasound-guided nerve block needle guidance in simulation.

PubMed

Morse, J; Terrasini, N; Wehbe, M; Philippona, C; Zaouter, C; Cyr, S; Hemmerling, T M

2014-06-01

This study focuses on a recently developed robotic nerve block system and its impact on learning regional anaesthesia skills. We compared success rates, learning curves, performance times, and inter-subject performance variability of robot-assisted vs manual ultrasound (US)-guided nerve block needle guidance. The hypothesis of this study is that robot assistance will result in faster skill acquisition than manual needle guidance. Five co-authors with different experience with nerve blocks and the robotic system performed both manual and robot-assisted, US-guided nerve blocks on two different nerves of a nerve phantom. Ten trials were performed for each of the four procedures. Time taken to move from a shared starting position till the needle was inserted into the target nerve was defined as the performance time. A successful block was defined as the insertion of the needle into the target nerve. Average performance times were compared using analysis of variance. P<0.05 was considered significant. Data presented as mean (standard deviation). All blocks were successful. There were significant differences in performance times between co-authors to perform the manual blocks, either superficial (P=0.001) or profound (P=0.0001); no statistical difference between co-authors was noted for the robot-assisted blocks. Linear regression indicated that the average decrease in time between consecutive trials for robot-assisted blocks of 1.8 (1.6) s was significantly (P=0.007) greater than the decrease for manual blocks of 0.3 (0.3) s. Robot assistance of nerve blocks allows for faster learning of needle guidance over manual positioning and reduces inter-subject performance variability. © The Author [2014]. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

How does information congruence influence diagnosis performance?

PubMed

Chen, Kejin; Li, Zhizhong

2015-01-01

Diagnosis performance is critical for the safety of high-consequence industrial systems. It depends highly on the information provided, perceived, interpreted and integrated by operators. This article examines the influence of information congruence (congruent information vs. conflicting information vs. missing information) and its interaction with time pressure (high vs. low) on diagnosis performance on a simulated platform. The experimental results reveal that the participants confronted with conflicting information spent significantly more time generating correct hypotheses and rated the results with lower probability values than when confronted with the other two levels of information congruence and were more prone to arrive at a wrong diagnosis result than when they were provided with congruent information. This finding stresses the importance of the proper processing of non-congruent information in safety-critical systems. Time pressure significantly influenced display switching frequency and completion time. This result indicates the decisive role of time pressure. Practitioner Summary: This article examines the influence of information congruence and its interaction with time pressure on human diagnosis performance on a simulated platform. For complex systems in the process control industry, the results stress the importance of the proper processing of non-congruent information in safety-critical systems.

Automated near-real-time clinical performance feedback for anesthesiology residents: one piece of the milestones puzzle.

PubMed

Ehrenfeld, Jesse M; McEvoy, Matthew D; Furman, William R; Snyder, Dylan; Sandberg, Warren S

2014-01-01

Anesthesiology residencies are developing trainee assessment tools to evaluate 25 milestones that map to the six core competencies. The effort will be facilitated by development of automated methods to capture, assess, and report trainee performance to program directors, the Accreditation Council for Graduate Medical Education and the trainees themselves. The authors leveraged a perioperative information management system to develop an automated, near-real-time performance capture and feedback tool that provides objective data on clinical performance and requires minimal administrative effort. Before development, the authors surveyed trainees about satisfaction with clinical performance feedback and about preferences for future feedback. Resident performance on 24,154 completed cases has been incorporated into the authors' automated dashboard, and trainees now have access to their own performance data. Eighty percent (48 of 60) of the residents responded to the feedback survey. Overall, residents "agreed/strongly agreed" that they desire frequent updates on their clinical performance on defined quality metrics and that they desired to see how they compared with the residency as a whole. Before deployment of the new tool, they "disagreed" that they were receiving feedback in a timely manner. Survey results were used to guide the format of the feedback tool that has been implemented. The authors demonstrate the implementation of a system that provides near-real-time feedback concerning resident performance on an extensible series of quality metrics, and which is responsive to requests arising from resident feedback about desired reporting mechanisms.

Automated Near Real-Time Clinical Performance Feedback for Anesthesiology Residents: One Piece of the Milestones Puzzle

PubMed Central

Ehrenfeld, Jesse M.; McEvoy, Matthew D.; Furman, William R.; Snyder, Dylan; Sandberg, Warren S.

2014-01-01

Background Anesthesiology residencies are developing trainee assessment tools to evaluate 25 milestones that map to the 6 core competencies. The effort will be facilitated by development of automated methods to capture, assess, and report trainee performance to program directors, the Accreditation Council for Graduate Medical Education and the trainees themselves. Methods We leveraged a perioperative information management system to develop an automated, near-real-time performance capture and feedback tool that provides objective data on clinical performance and requires minimal administrative effort. Prior to development, we surveyed trainees about satisfaction with clinical performance feedback and about preferences for future feedback. Results Resident performance on 24,154 completed cases has been incorporated into our automated dashboard, and trainees now have access to their own performance data. Eighty percent (48 of 60) of our residents responded to the feedback survey. Overall, residents ‘agreed/strongly agreed’ that they desire frequent updates on their clinical performance on defined quality metrics and that they desired to see how they compared to the residency as a whole. Prior to deployment of the new tool, they ‘disagreed’ that they were receiving feedback in a timely manner. Survey results were used to guide the format of the feedback tool that has been implemented. Conclusions We demonstrate the implementation of a system that provides near real-time feedback concerning resident performance on an extensible series of quality metrics, and which is responsive to requests arising from resident feedback about desired reporting mechanisms. PMID:24398735

Digital sleep logs reveal potential impacts of modern temporal structure on class performance in different chronotypes.

PubMed

Smarr, Benjamin Lee

2015-02-01

Stability of sleep and circadian rhythms are important for healthy learning and memory. While experimental manipulations of lifestyle and learning outcomes present major obstacles, the ongoing increase in data sources allows retrospective data mining of people's sleep timing variation. Here I use digital sleep-log data generated by 1109 students in a biology lab course at the University of Washington to test the hypothesis that higher variance in time asleep and later sleep-onset times negatively correlate with class performance, used here as a real-world proxy for learning and memory. I find that sleep duration variance and mean sleep-onset times both significantly correlate with class performance. These correlations are powerful on weeknights but undetectable on Friday and Saturday nights ("free nights"). Finally, although these data come with no demographic information beyond sex, the constructed demographic groups of "larks" and "owls" within the sexes reveal a significant decrease in performance of owls relative to larks in male students, whereas the correlation of performance with sleep-onset time for all male students was only a near-significant trend. This provides a proof of concept that deeper demographic mining of digital logs in the future may identify subgroups for which certain sleep phenotypes have greater predictive value for performance outcomes. The data analyzed are consistent with known patterns, including sleep-timing delays from weeknights to free nights and sleep-timing delays in men relative to women. These findings support the hypothesis that modern schedule impositions on sleep and circadian timing have consequences for real-world learning and memory. This study also highlights the low-cost, large-scale benefits of personal, daily, digital records as an augmentation of sleep and circadian studies. © 2015 The Author(s).

The effect of sleep quality on academic performance is mediated by Internet use time: DADOS study.

PubMed

Adelantado-Renau, Mireia; Diez-Fernandez, Ana; Beltran-Valls, Maria Reyes; Soriano-Maldonado, Alberto; Moliner-Urdiales, Diego

2018-05-19

The aims of the present study were to analyze the association of sleep patterns with academic and cognitive performance in adolescents, and to test the potential mediating effect of different activities of screen media usage on this association. A sample of 269 adolescents (140 boys) aged 14 years from the baseline data of the Deporte, ADOlescencia y Salud study completed questionnaires about sleep quality, cognitive performance, and leisure-time sedentary behaviors. Sleep duration was objectively computed using a wrist-worn GENEActiv accelerometer and academic performance was analyzed through school records. Sleep quality (but not sleep duration) was associated with all the academic performance indicators (all p<0.05). Analysis of covariance revealed higher grades among adolescents with better sleep quality (PSQI≤5; all p<0.05). These analyses showed no differences regarding cognitive performance. Internet use time was revealed as a mediator of the association between sleep quality and academic performance, being significant for all academic performance indicators (P M ranging from 15.5% to 16.0%). The association between sleep quality and academic performance in adolescents is mediated by time of Internet use. Overall, reducing Internet use in adolescents could be an achievable intervention for improving sleep quality, with potentially positive effects on academic performance. Copyright © 2018 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Temporal profile of prolonged, night-time driving performance: breaks from driving temporarily reduce time-on-task fatigue but not sleepiness.

PubMed

Phipps-Nelson, Jo; Redman, Jennifer R; Rajaratnam, Shantha M W

2011-09-01

Breaks are often used by drivers to counteract sleepiness and time-on-task fatigue during prolonged driving. We examined the temporal profile of changes in driving performance, electroencephalogram (EEG) activity and subjective measures of sleepiness and fatigue during prolonged nocturnal driving in a car simulator. In addition, the study examined the impact of regular breaks from driving on performance, sleepiness and fatigue. Healthy volunteers (n=12, 23-45 years) maintained a regular sleep-wake pattern for 14 days and were then in a laboratory from 21:00 to 08:30 hours. The driving simulator scene was designed to simulate monotonous night-time rural driving. Participants drove 4 × 2-h test sessions, with a break from driving of 1 h between each session. During the break participants performed tests assessing sleepiness and fatigue, and psychomotor performance (~30 mins), and then were permitted to sit quietly. They were monitored for wakefulness, and not permitted to nap or ingest caffeine. EEG was recorded during the driving task, and subjective assessments of sleepiness and fatigue were obtained at the start and completion of each session. We found that driving performance deteriorated (2.5-fold), EEG delta, theta and alpha activity increased, and subjective sleepiness and fatigue ratings increased across the testing period. Driving performance and fatigue ratings improved following the scheduled breaks from driving, while the breaks did not affect EEG activity and subjective sleepiness. Time-on-task effects increased through the testing period, indicating that these effects are exacerbated by increasing sleepiness. Breaks from driving without sleep temporarily ameliorate time-on-task fatigue, but provide little benefit to the sleepy driver. © 2010 European Sleep Research Society.

Does studying for an objective structured clinical examination make a difference?

PubMed

Mavis, B E

2000-10-01

This study examines the extent to which second-year medical students studied for an objective structured clinical examination (OSCE), how they studied, and the impact of self-reported studying on OSCE performance. One class of 113 medical students completed an end-of-second-year OSCE, held on two consecutive evenings. The OSCE was comprised of eight stations, each of which was of 20 minutes' duration. The OSCE was formative: students received performance feedback but were not graded. Prior to the OSCE, students completed a brief survey regarding their preparation for the OSCE and their perceptions of confidence, anxiety and preparedness. Only 78 students returned surveys with names, comprising the data for these analyses. Mean studying time was 3.3 h, ranging from 0 to 19 h. Studying time was positively associated with age and negatively associated with basic science examination scores. The most study time was dedicated to reviewing the physical examination textbook, class notes and supplemental course readings. The breadth of study strategies increased as more time was spent in OSCE preparation. OSCE performance was related to study time and to achievement on pre-clinical basic science examinations. The students whose performance was above average seemed to be the talented students whose records indicated a history of academic success. The amount of time they reported for OSCE preparation was comparable to that reported by students with below average performance. It appears that prior academic performance rather than preparatory studying time is a better predictor of OSCE outcomes.

The impact of continuous driving time and rest time on commercial drivers' driving performance and recovery.

PubMed

Wang, Lianzhen; Pei, Yulong

2014-09-01

This real road driving study was conducted to investigate the effects of driving time and rest time on the driving performance and recovery of commercial coach drivers. Thirty-three commercial coach drivers participated in the study, and were divided into three groups according to driving time: (a) 2 h, (b) 3 h, and (c) 4 h. The Stanford Sleepiness Scale (SSS) was used to assess the subjective fatigue level of the drivers. One-way ANOVA was employed to analyze the variation in driving performance. The statistical analysis revealed that driving time had a significant effect on the subjective fatigue and driving performance measures among the three groups. After 2 h of driving, both the subjective fatigue and driving performance measures began to deteriorate. After 4 h of driving, all of the driving performance indicators changed significantly except for depth perception. A certain amount of rest time eliminated the negative effects of fatigue. A 15-minute rest allowed drivers to recover from a two-hour driving task. This needed to be prolonged to 30 min for driving tasks of 3 to 4 h of continuous driving. Drivers' attention, reactions, operating ability, and perceptions are all affected in turn after over 2 h of continuous driving. Drivers should take a certain amount of rest to recover from the fatigue effects before they continue driving. Copyright © 2014 National Safety Council and Elsevier Ltd. All rights reserved.

Attitudes and Perspectives of Teacher Performers on Pedagogy and Perceived Student Learning in the Elementary and Secondary School Music Classroom

ERIC Educational Resources Information Center

Vitale, John L.

2015-01-01

This study investigated the lives of three active music teacher performers and how their performing experience impacted pedagogy and perceived student learning in the classroom. At the time of data collection, one participant was a full-time elementary school music teacher, and the other two participants were full-time secondary school music…

Influence of Planning Time and First-Move Strategy on Tower of Hanoi Problem-Solving Performance of Mentally Retarded Young Adults and Nonretarded Children.

ERIC Educational Resources Information Center

Spitz, Herman H.; And Others

1985-01-01

In two experiments using a computer-interfaced problem, planning time of 50 retarded young adults was as long as or longer than that of higher performing nonretarded children. In neither group was there a reliable correlation between planning time and performance. There were group differences in preferred strategies, possibly associated with…

Impact of hospital proportion and volume on primary percutaneous coronary intervention performance in England and Wales.

PubMed

West, Robert M; Cattle, Brian A; Bouyssie, Marianne; Squire, Iain; de Belder, Mark; Fox, Keith A A; Boyle, Roger; McLenachan, Jim M; Batin, Philip D; Greenwood, Darren C; Gale, Chris P

2011-03-01

To quantify the determinants of primary percutaneous coronary intervention (PCI) performance in England and Wales between 2004 and 2007. All 8653 primary PCI cases admitted to acute hospitals in England and Wales as recorded in the Myocardial Ischaemia National Audit Project (MINAP) 2004-2007. We studied the impact of the volume of primary PCI cases (hospital volume) on door-to-balloon (DTB) times and the proportion of patients treated with primary PCI (hospital proportion) on 30-day mortality and employed regression analysis to identify reasons for DTB time variations with a multilevel component to express hospital variation. The proportion of patients receiving primary PCI increased from 5% in 2004 to 20% in 2007. Median DTB times reduced from 84 min in 2004 to 61 min in 2007. Median DTB times decreased as the number of primary PCI procedures increased. The 30-day all-cause mortality rate for hospitals performing primary PCI on >25% of ST-elevation myocardial infarction patients [5.0%; 95% confidence interval (CI): 3.9-6.1%] was almost double that of hospitals performing primary PCI on more than 75% (2.7%; 95% CI: 2.0-3.5%). Time-of-day, year of admission, sex, and diabetes significantly influenced DTB times. Hospital variation was evident by a hospital-level DTB time standard deviation of 12 min. There was a large variation in DTB times between the best and worst performing hospitals. Although patient-related factors impacted upon DTB times, the volume and proportion of patients undergoing primary PCI were significantly associated with delay and early mortality-hospitals with the highest proportion of primary PCI had the lowest mortality.

Zero-Time Renal Transplant Biopsies: A Comprehensive Review.

PubMed

Naesens, Maarten

2016-07-01

Zero-time kidney biopsies, obtained at time of transplantation, are performed in many transplant centers worldwide. Decisions on kidney discard, kidney allocation, and choice of peritransplant and posttransplant treatment are sometimes based on the histological information obtained from these biopsies. This comprehensive review evaluates the practical considerations of performing zero-time biopsies, the predictive performance of zero-time histology and composite histological scores, and the clinical utility of these biopsies. The predictive performance of individual histological lesions and of composite scores for posttransplant outcome is at best moderate. No single histological lesion or composite score is sufficiently robust to be included in algorithms for kidney discard. Dual kidney transplantation has been based on histological assessment of zero-time biopsies and improves outcome in individual patients, but the waitlist effects of this strategy remain obscure. Zero-time biopsies are valuable for clinical and translational research purposes, providing insight in risk factors for posttransplant events, and as baseline for comparison with posttransplant histology. The molecular phenotype of zero-time biopsies yields novel therapeutic targets for improvement of donor selection, peritransplant management and kidney preservation. It remains however highly unclear whether the molecular expression variation in zero-time biopsies could become a better predictor for posttransplant outcome than donor/recipient baseline demographic factors.

Models of resource allocation optimization when solving the control problems in organizational systems

NASA Astrophysics Data System (ADS)

Menshikh, V.; Samorokovskiy, A.; Avsentev, O.

2018-03-01

The mathematical model of optimizing the allocation of resources to reduce the time for management decisions and algorithms to solve the general problem of resource allocation. The optimization problem of choice of resources in organizational systems in order to reduce the total execution time of a job is solved. This problem is a complex three-level combinatorial problem, for the solving of which it is necessary to implement the solution to several specific problems: to estimate the duration of performing each action, depending on the number of performers within the group that performs this action; to estimate the total execution time of all actions depending on the quantitative composition of groups of performers; to find such a distribution of the existing resource of performers in groups to minimize the total execution time of all actions. In addition, algorithms to solve the general problem of resource allocation are proposed.

Improving the Robustness of Real-Time Myoelectric Pattern Recognition against Arm Position Changes in Transradial Amputees

PubMed Central

Geng, Yanjuan; Wei, Yue

2017-01-01

Previous studies have showed that arm position variations would significantly degrade the classification performance of myoelectric pattern-recognition-based prosthetic control, and the cascade classifier (CC) and multiposition classifier (MPC) have been proposed to minimize such degradation in offline scenarios. However, it remains unknown whether these proposed approaches could also perform well in the clinical use of a multifunctional prosthesis control. In this study, the online effect of arm position variation on motion identification was evaluated by using a motion-test environment (MTE) developed to mimic the real-time control of myoelectric prostheses. The performance of different classifier configurations in reducing the impact of arm position variation was investigated using four real-time metrics based on dataset obtained from transradial amputees. The results of this study showed that, compared to the commonly used motion classification method, the CC and MPC configurations improved the real-time performance across seven classes of movements in five different arm positions (8.7% and 12.7% increments of motion completion rate, resp.). The results also indicated that high offline classification accuracy might not ensure good real-time performance under variable arm positions, which necessitated the investigation of the real-time control performance to gain proper insight on the clinical implementation of EMG-pattern-recognition-based controllers for limb amputees. PMID:28523276

Hotline Complaint Regarding A Defense Contract Audit Agency Employee Conducting Private For-Profit Tax Business Activity on Government Time and Using Government Equipment

DTIC Science & Technology

2011-06-28

auditors that have private businesses from performing private business tasks on Government time while teleworking . • Contact the U.S. Department of the...profit businesses and telework to perform tasks associated with their private businesses on Government time. Although teleworking did not cause the... teleworking , it increases the vulnerability that an unethical employee will misuse Government time. DCAA employs approximately 4,000 auditors, which is more

The influence of upper-body strength on flat-water sprint kayak performance in elite athletes.

PubMed

McKean, Mark R; Burkett, Brendan J

2014-07-01

Dry-land strength training is a fundamental component for elite kayak performance. The aims of this research were 3-fold: 1st, to determine the relationship between performance time and strength scores for elite kayakers; 2nd, to identify how strength changes (gains or losses) over 3 training y relate with changes in performance time for elite kayakers; and 3rd, to compare the progression in performance times for elite athletes with the top 3 performers from the national championships. The performance data for 15 elite male and 10 elite female kayakers were collected over 2 y. This group was reduced to 9 men and 8 women in the 3rd and final year. There were direct and significant correlations between strength scores and performance times across the 3 y. Bench-press 1RM increased by 34.8% for men and 42.3% for women. Over the 3 seasons, mean 1000-m time decreased by approximately 4.8%, 500-m times decreased by 7.3% (women), and 200-m times decreased by 9.1%. The women's 500-m changed from 11.9% difference from medalists to within 1.1% during the 3 y. During the 3 y of this study a change in 1-repetitionmaximum (1RM) bench press of 13% for men and 6.5% in women coincided with a change in performance times of 1%. For 1RM pull-up a change of 10% in men and 2.3% in women coincided with a change in performance times of 1%.

Effect of sintering time on the performance of turmeric dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Basuki, Hidajat, R. Lullus Lambang G.; Suyitno, Kristiawan, Budi; Rachmanto, Rendy Adhi

2017-01-01

This study reports the effect of sintering time on the performance of the dye-sensitized solar cells with turmeric dyes as sensitizers. Sintering TiO2 semiconductors were conducted at a temperature of 450°C for 30, 50, 90, 120, 150, and 180 minutes. The natural dye was extracted from dried turmeric powders with ethanol solvent. The results show that size of grains and the opening area of TiO2 semiconductor depended on the sintering time. The improvement of the properties of TiO2 semiconductor allowed more turmeric dyes were adsorbed by the semiconductors and then improved the performance of solar cells. The sintering time of 150 minutes produced large grains with an average diameter of 68.87 nm, and a porosity area of 26.51% caused the performance of DSSCs was the highest among other sintering time. The Voc, Jsc, and efficiency of DSSCs with turmeric-based natural dyes 0.64 V, 0.47 mA/cm2, and 0.2%, respectively.

Improving on-time surgical starts: the impact of implementing pre-OR timeouts and performance pay.

PubMed

Martin, Luke; Langell, John

2017-11-01

Operating room (OR) time is expensive. Underutilized OR time negatively impacts efficiency and is an unnecessary cost for hospitals. The purpose of this study was to evaluate the impact of a pre-OR timeout and performance pay incentive on the frequency of on-time, first surgical starts. At a single Veterans Affairs Medical Center, we implemented a pre-OR timeout in the form of a safety-briefing checklist and a modest performance pay incentive for on-time starts (>90% compliance) for attending surgeons. Data were collected on all first-start cases beginning before implementation in 2008 and continued through 2015. Each year, an average of 960 first starts occurred across nine surgical divisions. Before implementation of either the timeout or pay incentive, only 15% of cases started on time, and by 2015, greater than 72% were on time (P < 0.001). Over the study period, there were significant improvements in on-time starts (P = 0.01), of delays <15 min (P = 0.01), and of delays 16 to 30 min (P = 0.04). The trends for delays of 31 to 60 min or >60 min were not significant (P = 0.31; P = 0.81). Assuming a loss of 7 min per case for delays <15 min and 20 min per case for delays of 16 to 30 min, the total OR time saved from implementing these measures was 37,556 min. At an estimated cost of $20/min, gross savings from this project were $751,120. Implementation of a pre-OR timeout and performance pay for on-time starts significantly improves OR utilization and reduces unnecessary costs. Published by Elsevier Inc.

27 CFR 70.306 - Time for performance of acts other than payment of tax or filing of any return when the last day...

Code of Federal Regulations, 2013 CFR

2013-04-01

... acts other than payment of tax or filing of any return when the last day falls on Saturday, Sunday, or... performance of acts other than payment of tax or filing of any return when the last day falls on Saturday... falls on a Saturday, Sunday, or legal holiday, such act shall be considered performed timely if...

27 CFR 70.306 - Time for performance of acts other than payment of tax or filing of any return where last day...

Code of Federal Regulations, 2010 CFR

2010-04-01

... acts other than payment of tax or filing of any return where last day falls on Saturday, Sunday, or... performance of acts other than payment of tax or filing of any return where last day falls on Saturday, Sunday... falls on a Saturday, Sunday, or legal holiday, such act shall be considered performed timely if...

27 CFR 70.306 - Time for performance of acts other than payment of tax or filing of any return when the last day...

Code of Federal Regulations, 2011 CFR

2011-04-01

... acts other than payment of tax or filing of any return when the last day falls on Saturday, Sunday, or... performance of acts other than payment of tax or filing of any return when the last day falls on Saturday... falls on a Saturday, Sunday, or legal holiday, such act shall be considered performed timely if...

27 CFR 70.306 - Time for performance of acts other than payment of tax or filing of any return when the last day...

Code of Federal Regulations, 2012 CFR

2012-04-01

... acts other than payment of tax or filing of any return when the last day falls on Saturday, Sunday, or... performance of acts other than payment of tax or filing of any return when the last day falls on Saturday... falls on a Saturday, Sunday, or legal holiday, such act shall be considered performed timely if...

27 CFR 70.306 - Time for performance of acts other than payment of tax or filing of any return when the last day...

Code of Federal Regulations, 2014 CFR

2014-04-01

... acts other than payment of tax or filing of any return when the last day falls on Saturday, Sunday, or... performance of acts other than payment of tax or filing of any return when the last day falls on Saturday... falls on a Saturday, Sunday, or legal holiday, such act shall be considered performed timely if...

Morning employees are perceived as better employees: employees' start times influence supervisor performance ratings.

PubMed

Yam, Kai Chi; Fehr, Ryan; Barnes, Christopher M

2014-11-01

In this research, we draw from the stereotyping literature to suggest that supervisor ratings of job performance are affected by employees' start times-the time of day they first arrive at work. Even when accounting for total work hours, objective job performance, and employees' self-ratings of conscientiousness, we find that a later start time leads supervisors to perceive employees as less conscientious. These perceptions in turn cause supervisors to rate employees as lower performers. In addition, we show that supervisor chronotype acts as a boundary condition of the mediated model. Supervisors who prefer eveningness (i.e., owls) are less likely to hold negative stereotypes of employees with late start times than supervisors who prefer morningness (i.e., larks). Taken together, our results suggest that supervisor ratings of job performance are susceptible to stereotypic beliefs based on employees' start times. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

AN EXPERIMENT IN BASIC AIRBORNE ELECTRONICS TRAINING, PART IV-- EFFECT OF REDUCTION IN TRAINING TIME ON FLEET PERFORMANCE. FINAL REPORT.

ERIC Educational Resources Information Center

BALDWIN, ROBERT O.; AND OTHERS

THREE PRECEDING REPORTS PRESENTED THE EFFECTS OF SHORTENING TRAINING TIME IN AVIONICS FUNDAMENTALS AND AVIATION ELECTRONICS TECHNICIAN (RADAR) TRAINING UPON THE FINAL COMPREHENSIVE EXAMINATION IN THESE COURSES AND UPON PERFORMANCE IN A SUBSEQUENT EQUIPMENT COURSE. THIS REPORT COMPARES THE ON THE JOB PERFORMANCE OF GRADUATES FROM FOUR GROUPS…

Rotor design for maneuver performance

NASA Technical Reports Server (NTRS)

Berry, John D.; Schrage, Daniel

1986-01-01

A method of determining the sensitivity of helicopter maneuver performance to changes in basic rotor design parameters is developed. Maneuver performance is measured by the time required, based on a simplified rotor/helicopter performance model, to perform a series of specified maneuvers. This method identifies parameter values which result in minimum time quickly because of the inherent simplicity of the rotor performance model used. For the specific case studied, this method predicts that the minimum time required is obtained with a low disk loading and a relatively high rotor solidity. The method was developed as part of the winning design effort for the American Helicopter Society student design competition for 1984/1985.

Comparison of physical therapy anatomy performance and anxiety scores in timed and untimed practical tests.

PubMed

Schwartz, Sarah M; Evans, Cathy; Agur, Anne M R

2015-01-01

Students in health care professional programs face many stressful tests that determine successful completion of their program. Test anxiety during these high stakes examinations can affect working memory and lead to poor outcomes. Methods of decreasing test anxiety include lengthening the time available to complete examinations or evaluating students using untimed examinations. There is currently no consensus in the literature regarding whether untimed examinations provide a benefit to test performance in clinical anatomy. This study aimed to determine the impact of timed versus untimed practical tests on Master of Physical Therapy student anatomy performance and test anxiety. Test anxiety was measured using the State-Trait Anxiety Inventory (STAI). Differences in performance, anxiety scores, and time taken were compared using paired sample Student's t-tests. Eighty-one of the 84 students completed the study and provided feedback. Students performed significantly higher on the untimed test (P = 0.005), with a significant reduction in test anxiety (P < 0.001). Students who were unsuccessful on the timed test showed the greatest improvement on the untimed test ( x¯ = 20.4 ±10%). Eighty-three percent (n = 69) of students preferred the untimed test, 8.4% (n = 7) the timed test, and 8.4% (n = 7) had no preference. Students took on average eight minutes longer on the untimed test. This study found that physical therapy students perform better on untimed tests, which may be related to a reduction in test anxiety. If the intended goal of evaluating health care professional students is to determine fundamental competencies, these factors should be considered when designing future curricula. © 2014 American Association of Anatomists.

A tool for modeling concurrent real-time computation

NASA Technical Reports Server (NTRS)

Sharma, D. D.; Huang, Shie-Rei; Bhatt, Rahul; Sridharan, N. S.

1990-01-01

Real-time computation is a significant area of research in general, and in AI in particular. The complexity of practical real-time problems demands use of knowledge-based problem solving techniques while satisfying real-time performance constraints. Since the demands of a complex real-time problem cannot be predicted (owing to the dynamic nature of the environment) powerful dynamic resource control techniques are needed to monitor and control the performance. A real-time computation model for a real-time tool, an implementation of the QP-Net simulator on a Symbolics machine, and an implementation on a Butterfly multiprocessor machine are briefly described.

The reaction times of drivers aged 20 to 80 during a divided attention driving.

PubMed

Svetina, Matija

2016-11-16

Many studies addressing age-related changes in driving performance focus on comparing young vs. older drivers, which might lead to the biased conclusion that driving performance decreases only after the age of 65. The main aim of the study was to show that changes in driving performance are progressive throughout the adult years. A sample of 351 drivers aged 20 to 80 was assessed for their reaction times while driving between road cones. The drivers were exposed to 2 conditions varying according to task complexity. In single task conditions, the drivers performed a full stopping maneuver at a given signal; in dual task conditions, the drivers were distracted before the signal for stopping maneuver was triggered. Reaction times were compared across conditions and age groups. The results showed that both reaction times and variability of driving performance increased progressively between the ages of 20 and 80. The increase in both reaction times and variability was greater in the complex task condition. The high-performing quarter of elderly drivers performed equally well or better than younger drivers did. The data clearly supported the claim that driving performance changes steadily across age groups: both mean reaction time and interindividual variability progressively increase with age. In addition, a significant group of older drivers was identified who did not show the expected age-related decrease in performance. The findings have important implications, suggesting that in relation to driving, aging is a progressive phenomenon and may lead to variety of driving performance; age-related studies of driving performance should put more emphasis on investigating changes across the whole driver age range rather than only comparing younger and older drivers.

Work-group characteristics and performance in collectivistic and individualistic cultures.

PubMed

Sosik, John J; Jung, Dong I

2002-02-01

The authors conducted a cross-cultural longitudinal investigation of the effects of culture (individualism-collectivism dichotomy) on group characteristics (functional heterogeneity, preference for teamwork, group potency, outcome expectation) and on performance of 83 work groups performing 2 decision-making tasks over a 15-week period. The individualists (U.S. students) reported higher levels of functional heterogeneity and group potency and attained higher levels of group performance than did the collectivists (Korean students). In addition, culture and time interacted to influence ratings of group potency and outcome expectation. The difference in ratings of group potency between individualists and collectivists increased over time. Outcome expectation was greater among the collectivists in Time 1 and among the individualists in Time 2. The authors discuss implications for future cross-cultural group research and international management.

An Integrated Architecture for On-Board Aircraft Engine Performance Trend Monitoring and Gas Path Fault Diagnostics

NASA Technical Reports Server (NTRS)

Simon, Donald L.

2010-01-01

Aircraft engine performance trend monitoring and gas path fault diagnostics are closely related technologies that assist operators in managing the health of their gas turbine engine assets. Trend monitoring is the process of monitoring the gradual performance change that an aircraft engine will naturally incur over time due to turbomachinery deterioration, while gas path diagnostics is the process of detecting and isolating the occurrence of any faults impacting engine flow-path performance. Today, performance trend monitoring and gas path fault diagnostic functions are performed by a combination of on-board and off-board strategies. On-board engine control computers contain logic that monitors for anomalous engine operation in real-time. Off-board ground stations are used to conduct fleet-wide engine trend monitoring and fault diagnostics based on data collected from each engine each flight. Continuing advances in avionics are enabling the migration of portions of the ground-based functionality on-board, giving rise to more sophisticated on-board engine health management capabilities. This paper reviews the conventional engine performance trend monitoring and gas path fault diagnostic architecture commonly applied today, and presents a proposed enhanced on-board architecture for future applications. The enhanced architecture gains real-time access to an expanded quantity of engine parameters, and provides advanced on-board model-based estimation capabilities. The benefits of the enhanced architecture include the real-time continuous monitoring of engine health, the early diagnosis of fault conditions, and the estimation of unmeasured engine performance parameters. A future vision to advance the enhanced architecture is also presented and discussed

Hospital nurse job attitudes and performance: the impact of employment status.

PubMed

Chu, Cheng-I; Hsu, Yao-Feng

2011-03-01

According to the 2007 Taiwan Labor Front Human Resources Report, as much as 47.6% of nurses at some public hospitals were contracted rather than full time. Furthermore, turnover rates for contract nurses were found to be as high as five to eight times of those for full-time nurses. Because high turnover rates are likely to induce negative impacts on the stability of care provided in the absence of staffing continuity, the association between nursing employment arrangement and nursing care quality is attracting greater attention. This study was designed to investigate the work status of contract versus full-time nurses at a public hospital in Taiwan and to examine the impact of such on work-related attitudes, organizational citizenship behavior, and job performance. Samples were recruited from a public hospital in Taiwan. In addition to self-rated items, researchers used supervisor-rated structured questionnaires for job performance to attenuate the possible effect of common method bias. The study investigated the impact of hospital nurse employment status on work-related attitudes, organizational citizenship behavior, and job performance using a regression model that included the critical work-related attitudes variables of job satisfaction and organizational commitment. Study findings included the following: (a) organizational commitment, job satisfaction, organizational citizenship behavior, and job performance correlate positively with one another. (b) No significant difference between contract and full-time nurses was found in terms of organizational commitment, job satisfaction, organizational citizenship behavior, and self-rated job performance. However, when rated by supervisors, reported job performance levels for full-time nurses were significantly higher than those of contract nurses. (c) Organizational citizenship behavior exhibited a mediating effect between job satisfaction, organizational commitment, and job performance. In this study, supervisors gave higher job performance ratings to full-time nurses than to contract nurses. This result deserves further investigation.

Performance time transformed by count as a determinant of difficulty in the Shotokan karate Heian kata set.

PubMed

Layton, C; Lawrence, J M

1997-06-01

Black-belt subjects (10 men) were timed on each of the five Heian kata and the scores transformed by count. Trend analyses showed that increased performance time was significantly related to assumed complexity in Heian ranking.

Effect of Detector Dead Time on the Performance of Optical Direct-Detection Communication Links

NASA Technical Reports Server (NTRS)

Chen, C.-C.

1988-01-01

Avalanche photodiodes (APDs) operating in the Geiger mode can provide a significantly improved single-photon detect ion sensitivity over conventional photodiodes. However, the quenching circuit required to remove the excess charge carriers after each photon event can introduce an undesirable dead time into the detection process. The effect of this detector dead time on the performance of a binary pulse-position-modulted (PPM) channel is studied by analyzing the error probability. It is shown that, when back- ground noise is negligible, the performance of the detector with dead time is similar to that o f a quantum-limited receiver. For systems with increasing background intensities, the error rate of the receiver starts to degrade rapidly with increasing dead time. The power penalty due to detector dead time is also evaluated and shown to depend critically on background intensity as well as dead time. Given the expected background strength in an optical channel, therefore, a constraint must be placed on the bandwidth of the receiver to limit the amount of power penalty due to detector dead time.

Effect of detector dead time on the performance of optical direct-detection communication links

NASA Astrophysics Data System (ADS)

Chen, C.-C.

1988-05-01

Avalanche photodiodes (APDs) operating in the Geiger mode can provide a significantly improved single-photon detection sensitivity over conventional photodiodes. However, the quenching circuit required to remove the excess charge carriers after each photon event can introduce an undesirable dead time into the detection process. The effect of this detector dead time on the performance of a binary pulse-position-modulated (PPM) channel is studied by analyzing the error probability. It is shown that, when background noise is negligible, the performance of the detector with dead time is similar to that of a quantum-limited receiver. For systems with increasing background intensities, the error rate of the receiver starts to degrade rapidly with increasing dead time. The power penalty due to detector dead time is also evaluated and shown to depend critically on badkground intensity as well as dead time. Given the expected background strength in an optical channel, therefore, a constraint must be placed on the bandwidth of the receiver to limit the amount of power penalty due to detector dead time.

Differences in kata performance time and distance from a marker for experienced Shotokan karateka under normal sighted and blindfolded conditions.

PubMed

Layton, Clive; Avenell, Leon

2002-08-01

10 experienced Shotokan karateka were tested on performance time and distance from a marker on the five Heian kata under normal sighted and blind-folded conditions. Whilst each kata's line of movement is different, it is the intention to start and finish at the same location. Analysis showed that despite an average of 16.8 yr. of training, whilst timing was not significantly affected on four of the kata by subjects being deprived of the visual sense, the group's mean change in distance from an original marker was significant for performances on three of the kata.

Effects of Above Real Time Training (ARTT) On Individual Skills and Contributions to Crew/Team Performance

NASA Technical Reports Server (NTRS)

Ali, Syed Firasat; Khan, M. Javed; Rossi, Marcia J.; Crane, Peter; Guckenberger, Dutch; Bageon, Kellye

2001-01-01

Above Real Time Training (ARTT) is the training acquired on a real time simulator when it is modified to present events at a faster pace than normal. The experiments on training of pilots performed by NASA engineers and others have indicated that real time training (RTT) reinforced with ARTT would offer an effective training strategy for such tasks which require significant effort at time and workload management. A study was conducted to find how ARTT and RTT complement each other for training of novice pilot-navigator teams to fly on a required route. In the experiment, each of the participating pilot-navigator teams was required to conduct simulator flights on a prescribed two-legged ground track while maintaining required air speed and altitude. At any instant in a flight, the distance between the actual spatial point location of the airplane and the required spatial point was used as a measure of deviation from the required route. A smaller deviation represented better performance. Over a segment of flight or over complete flight, an average value of the deviation represented consolidated performance. The deviations were computed from the information on latitude, longitude, and altitude. In the combined ARTT and RTT program, ARTT at intermediate training intervals was beneficial in improving the real time performance of the trainees. It was observed that the team interaction between pilot and navigator resulted in maintaining high motivation and active participation throughout the training program.

Task Switching Effects in Anticipation Timing

ERIC Educational Resources Information Center

Fairbrother, Jeffrey T.; Brueckner, Sebastian

2008-01-01

To understand how task switching affects human performance, there is a need to investigate how it influences the performance of tasks other than those involving bivalent stimulus categorization. The purpose of this study, therefore, was to investigate the effects of task switching on anticipation timing performance, which typically requires…

Dissociable effects of practice variability on learning motor and timing skills.

PubMed

Caramiaux, Baptiste; Bevilacqua, Frédéric; Wanderley, Marcelo M; Palmer, Caroline

2018-01-01

Motor skill acquisition inherently depends on the way one practices the motor task. The amount of motor task variability during practice has been shown to foster transfer of the learned skill to other similar motor tasks. In addition, variability in a learning schedule, in which a task and its variations are interweaved during practice, has been shown to help the transfer of learning in motor skill acquisition. However, there is little evidence on how motor task variations and variability schedules during practice act on the acquisition of complex motor skills such as music performance, in which a performer learns both the right movements (motor skill) and the right time to perform them (timing skill). This study investigated the impact of rate (tempo) variability and the schedule of tempo change during practice on timing and motor skill acquisition. Complete novices, with no musical training, practiced a simple musical sequence on a piano keyboard at different rates. Each novice was assigned to one of four learning conditions designed to manipulate the amount of tempo variability across trials (large or small tempo set) and the schedule of tempo change (randomized or non-randomized order) during practice. At test, the novices performed the same musical sequence at a familiar tempo and at novel tempi (testing tempo transfer), as well as two novel (but related) sequences at a familiar tempo (testing spatial transfer). We found that practice conditions had little effect on learning and transfer performance of timing skill. Interestingly, practice conditions influenced motor skill learning (reduction of movement variability): lower temporal variability during practice facilitated transfer to new tempi and new sequences; non-randomized learning schedule improved transfer to new tempi and new sequences. Tempo (rate) and the sequence difficulty (spatial manipulation) affected performance variability in both timing and movement. These findings suggest that there is a dissociable effect of practice variability on learning complex skills that involve both motor and timing constraints.

Effect of nucleation time on bending response of ionic polymer–metal composite actuators

DOE PAGES

Kim, Suran; Hong, Seungbum; Choi, Yoon-Young; ...

2013-07-02

We attempted an autocatalytic electro-less plating of nickel in order to replace an electroless impregnation-reduction (IR) method in ionic polymer–metal composite (IPMC) actuators to reduce cost and processing time. Because nucleation time of Pd–Sn colloids is the determining factor of overall processing time, we used the nucleation time as our control parameter. In order to optimize nucleation time and investigate its effect on the performance of IPMC actuators, we analyzed the relationship between the nucleation time, interface morphology and electrical properties. The optimized nucleation time was 10 h. Furthermore, the trends of the performance and electrical properties as a functionmore » of nucleation time were attributed to the fact that the Ni penetration depth was determined by the minimum diffusion length of either Pd–Sn colloids or reducing agent ions. The Ni-IPMC actuators can be fabricated less than 14 h processing time without deteriorating performance of the actuators, which is comparable to Pt-IPMC prepared by IR method.« less

Documentation and user's guide for interactive spectral analysis and filter program package useful in the processing of seismic reflection data

USGS Publications Warehouse

Miller, J.J.

1982-01-01

The spectral analysis and filter program package is written in the BASIC language for the HP-9845T desktop computer. The program's main purpose is to perform spectral analyses on digitized time-domain data. In addition, band-pass filtering of the data can be performed in the time domain. Various other processes such as autocorrelation can be performed to the time domain data in order to precondition them for spectral analyses. The frequency domain data can also be transformed back into the time domain if desired. Any data can be displayed on the CRT in graphic form using a variety of plot routines. A hard copy can be obtained immediately using the internal thermal printer. Data can also be displayed in tabular form on the CRT or internal thermal printer or it can be stored permanently on a mass storage device like a tape or disk. A list of the processes performed in the order in which they occurred can be displayed at any time.

Time-sharing ability in complex performance : an expanded replication.

DOT National Transportation Integrated Search

1978-09-01

Factor analyses were performed on data from 51 subjects tested on the CAMI Multiple Task Performance Battery (MTPB). Five different complex performance task combinations were used as well as the six individual MTPB tasks performed by themselves. The ...

Extended Time Accommodations and the Mathematics Performance of Students with and without ADHD

ERIC Educational Resources Information Center

Lewandowski, Lawrence J.; Lovett, Benjamin J.; Parolin, Rosanne; Gordon, Michael; Codding, Robin S.

2007-01-01

Test accommodations such as extended time are presumed to reduce the impact of a disability, while not affecting test scores of the general population. This study examined the effects of an extended time (time and one-half) accommodation on the mathematics performance of fifth- to seventh-grade students with and without attention deficit…

Age and measurement time-of-day effects on speech recognition in noise.

PubMed

Veneman, Carrie E; Gordon-Salant, Sandra; Matthews, Lois J; Dubno, Judy R

2013-01-01

The purpose of this study was to determine the effect of measurement time of day on speech recognition in noise and the extent to which time-of-day effects differ with age. Older adults tend to have more difficulty understanding speech in noise than younger adults, even when hearing is normal. Two possible contributors to this age difference in speech recognition may be measurement time of day and inhibition. Most younger adults are "evening-type," showing peak circadian arousal in the evening, whereas most older adults are "morning-type," with circadian arousal peaking in the morning. Tasks that require inhibition of irrelevant information have been shown to be affected by measurement time of day, with maximum performance attained at one's peak time of day. The authors hypothesized that a change in inhibition will be associated with measurement time of day and therefore affect speech recognition in noise, with better performance in the morning for older adults and in the evening for younger adults. Fifteen younger evening-type adults (20-28 years) and 15 older morning-type adults with normal hearing (66-78 years) listened to the Hearing in Noise Test (HINT) and the Quick Speech in Noise (QuickSIN) test in the morning and evening (peak and off-peak times). Time of day preference was assessed using the Morningness-Eveningness Questionnaire. Sentences and noise were presented binaurally through insert earphones. During morning and evening sessions, participants solved word-association problems within the visual-distraction task (VDT), which was used as an estimate of inhibition. After each session, participants rated perceived mental demand of the tasks using a revised version of the NASA Task Load Index. Younger adults performed significantly better on the speech-in-noise tasks and rated themselves as requiring significantly less mental demand when tested at their peak (evening) than off-peak (morning) time of day. In contrast, time-of-day effects were not observed for the older adults on the speech recognition or rating tasks. Although older adults required significantly more advantageous signal-to-noise ratios than younger adults for equivalent speech-recognition performance, a significantly larger younger versus older age difference in speech recognition was observed in the evening than in the morning. Older adults performed significantly poorer than younger adults on the VDT, but performance was not affected by measurement time of day. VDT performance for misleading distracter items was significantly correlated with HINT and QuickSIN test performance at the peak measurement time of day. Although all participants had normal hearing, speech recognition in noise was significantly poorer for older than younger adults, with larger age-related differences in the evening (an off-peak time for older adults) than in the morning. The significant effect of measurement time of day suggests that this factor may impact the clinical assessment of speech recognition in noise for all individuals. It appears that inhibition, as estimated by a visual distraction task for misleading visual items, is a cognitive mechanism that is related to speech-recognition performance in noise, at least at a listener's peak time of day.

Versatile analog pulse height computer performs real-time arithmetic operations

NASA Technical Reports Server (NTRS)

Brenner, R.; Strauss, M. G.

1967-01-01

Multipurpose analog pulse height computer performs real-time arithmetic operations on relatively fast pulses. This computer can be used for identification of charged particles, pulse shape discrimination, division of signals from position sensitive detectors, and other on-line data reduction techniques.

Time assignment system and its performance aboard the Hitomi satellite

NASA Astrophysics Data System (ADS)

Terada, Yukikatsu; Yamaguchi, Sunao; Sugimoto, Shigenobu; Inoue, Taku; Nakaya, Souhei; Murakami, Maika; Yabe, Seiya; Oshimizu, Kenya; Ogawa, Mina; Dotani, Tadayasu; Ishisaki, Yoshitaka; Mizushima, Kazuyo; Kominato, Takashi; Mine, Hiroaki; Hihara, Hiroki; Iwase, Kaori; Kouzu, Tomomi; Tashiro, Makoto S.; Natsukari, Chikara; Ozaki, Masanobu; Kokubun, Motohide; Takahashi, Tadayuki; Kawakami, Satoko; Kasahara, Masaru; Kumagai, Susumu; Angelini, Lorella; Witthoeft, Michael

2018-01-01

Fast timing capability in x-ray observation of astrophysical objects is one of the key properties for the ASTRO-H (Hitomi) mission. Absolute timing accuracies of 350 or 35 μs are required to achieve nominal scientific goals or to study fast variabilities of specific sources. The satellite carries a GPS receiver to obtain accurate time information, which is distributed from the central onboard computer through the large and complex SpaceWire network. The details of the time system on the hardware and software design are described. In the distribution of the time information, the propagation delays and jitters affect the timing accuracy. Six other items identified within the timing system will also contribute to absolute time error. These error items have been measured and checked on ground to ensure the time error budgets meet the mission requirements. The overall timing performance in combination with hardware performance, software algorithm, and the orbital determination accuracies, etc. under nominal conditions satisfies the mission requirements of 35 μs. This work demonstrates key points for space-use instruments in hardware and software designs and calibration measurements for fine timing accuracy on the order of microseconds for midsized satellites using the SpaceWire (IEEE1355) network.

Watching the clock

PubMed Central

Fetterman, J. Gregor; Killeen, Peter R.; Hall, Scott

2008-01-01

Four rats and four pigeons were monitored while performing retrospective timing tasks. All animals displayed collateral behaviors which could have mediated their temporal judgements. Statistical analysis made a good case for such mediation in the case of two pigeons performing on a spatially-differentiated response, but not for the two responding on a color-differentiated response. For the rats, all of which performed on a spatially-differentiated task, prediction of their temporal judgements was always better if based on collateral activity than if based on the passage of time. PMID:19701487

Performance determinants of fixed gear cycling during criteriums.

PubMed

Babault, Nicolas; Poisson, Maxime; Cimadoro, Guiseppe; Cometti, Carole; Païzis, Christos

2018-06-17

Nowadays, fixed gear competitions on outdoor circuits such as criteriums are regularly organized worldwide. To date, no study has investigated this alternative form of cycling. The purpose of the present study was to examine fixed gear performance indexes and to characterize physiological determinants of fixed gear cyclists. This study was carried out in two parts. Part 1 (n = 36) examined correlations between performance indexes obtained during a real fixed gear criterium (time trial, fastest laps, averaged lap time during races, fatigue indexes) and during a sprint track time trial. Part 2 (n = 9) examined correlations between the recorded performance indexes and some aerobic and anaerobic performance outputs (VO 2max , maximal aerobic power, knee extensor and knee flexor maximal voluntary torque, vertical jump height and performance during a modified Wingate test). Results from Part 1 indicated significant correlations between fixed gear final performance (i.e. average lap time during the finals) and single lap time (time trial, fastest lap during races and sprint track time trial). In addition, results from Part 2 revealed significant correlations between fixed gear performance and aerobic indicators (VO 2max and maximal aerobic power). However, no significant relationship was obtained between fixed gear cycling and anaerobic qualities such as strength. Similarly to traditional cycling disciplines, we concluded that fixed gear cycling is mainly limited by aerobic capacity, particularly criteriums final performance. However, specific skills including technical competency should be considered.

Feedback and the rationing of time and effort among competing tasks.

PubMed

Northcraft, Gregory B; Schmidt, Aaron M; Ashford, Susan J

2011-09-01

The study described here tested a model of how characteristics of the feedback environment influence the allocation of resources (time and effort) among competing tasks. Results demonstrated that performers invest more resources on tasks for which higher quality (more timely and more specific) feedback is available; this effect was partially mediated by task salience and task expectancies. Feedback timing and feedback specificity demonstrated both main and interaction effects on resource allocations. Results also demonstrated that performers do better on tasks for which higher quality feedback is available; this effect was mediated by resources allocated to tasks. The practical and theoretical implications of the role of the feedback environment in managing performance are discussed. PsycINFO Database Record (c) 2011 APA, all rights reserved

The relationship between sleep habits and academic performance in dental students in Croatia.

PubMed

Valic, M; Pecotic, R; Lusic, L; Peros, K; Pribudic, Z; Dogas, Z

2014-11-01

It is well accepted that sleep and lifestyle habits affect academic success in students. However, sleep patterns and sleep problems amongst dental students have been insufficiently addressed in the literature. The purpose of this study was to evaluate sleep habits of dental students and the relationship between sleep habits and academic performance. A self-administered questionnaire on sleep habits, academic performance and lifestyle was administered. The participants were 447 dental students from Split University Dental Medicine School and Zagreb University Dental Medicine School from the six academic years. The subjects were classified into two groups based on academic success (high-performing vs. low-performing students) for comparison of sleep and lifestyle habits. Amongst the whole group of students, average bedtime and wake time during weekday was significantly earlier compared with weekend. Main findings indicate that students with high academic performance had earlier bedtimes during weekdays and weekends, earlier wake times during weekends and shorter sleep latency compared with low academic performing students. Self-reported academic performance of dental students in Croatia is associated with timing of sleep and wakefulness, rather than with total sleep time duration. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Numerical Modeling of Pulse Detonation Rocket Engine Gasdynamics and Performance

NASA Technical Reports Server (NTRS)

2003-01-01

This paper presents viewgraphs on the numerical modeling of pulse detonation rocket engines (PDRE), with an emphasis on the Gasdynamics and performance analysis of these engines. The topics include: 1) Performance Analysis of PDREs; 2) Simplified PDRE Cycle; 3) Comparison of PDRE and Steady-State Rocket Engines (SSRE) Performance; 4) Numerical Modeling of Quasi 1-D Rocket Flows; 5) Specific PDRE Geometries Studied; 6) Time-Accurate Thrust Calculations; 7) PDRE Performance (Geometries A B C and D); 8) PDRE Blowdown Gasdynamics (Geom. A B C and D); 9) PDRE Geometry Performance Comparison; 10) PDRE Blowdown Time (Geom. A B C and D); 11) Specific SSRE Geometry Studied; 12) Effect of F-R Chemistry on SSRE Performance; 13) PDRE/SSRE Performance Comparison; 14) PDRE Performance Study; 15) Grid Resolution Study; and 16) Effect of F-R Chemistry on SSRE Exit Species Mole Fractions.

Sildenafil has little influence on cardiovascular hemodynamics or 6-km time trial performance in trained men and women at simulated high altitude.

PubMed

Jacobs, Kevin A; Kressler, Jochen; Stoutenberg, Mark; Roos, Bernard A; Friedlander, Anne L

2011-01-01

Sildenafil improves maximal exercise capacity at high altitudes (∼4350-5800 m) by reducing pulmonary arterial pressure and enhancing oxygen delivery, but the effects on exercise performance at less severe altitudes are less clear. To determine the effects of sildenafil on cardiovascular hemodynamics (heart rate, stroke volume, and cardiac output), arterial oxygen saturation (SaO2), and 6-km time-trial performance of endurance-trained men and women at a simulated altitude of ∼3900 m. Twenty men and 15 women, endurance-trained, completed one experimental exercise trial (30 min at 55% of altitude-specific capacity +6-km time trial) at sea level (SL) and two trials at simulated high altitude (HA) while breathing hypoxic gas (12.8% FIo2) after ingestion of either placebo or 50 mg sildenafil in double-blind, randomized, and counterbalanced fashion. Maximal exercise capacity and SaO2 were significantly reduced at HA compared to SL (18%-23%), but sildenafil did not significantly improve cardiovascular hemodynamics or time-trial performance in either men or women compared to placebo and only improved SaO2 in women (4%). One male subject (5% of male subjects, 2.8% of all subjects) exhibited a meaningful 36-s improvement in time-trial performance with sildenafil compared to placebo. In this group of endurance trained men and women, sildenafil had very little influence on cardiovascular hemodynamics, SaO2, and 6-km time-trial performance at a simulated altitude of ∼3900 m. It appears that a very small percentage of endurance-trained men and women derive meaningful improvements in aerobic performance from sildenafil at a simulated altitude of ∼3900 m.

EnergyPlus Run Time Analysis

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

Hong, Tianzhen; Buhl, Fred; Haves, Philip

2008-09-20

EnergyPlus is a new generation building performance simulation program offering many new modeling capabilities and more accurate performance calculations integrating building components in sub-hourly time steps. However, EnergyPlus runs much slower than the current generation simulation programs. This has become a major barrier to its widespread adoption by the industry. This paper analyzed EnergyPlus run time from comprehensive perspectives to identify key issues and challenges of speeding up EnergyPlus: studying the historical trends of EnergyPlus run time based on the advancement of computers and code improvements to EnergyPlus, comparing EnergyPlus with DOE-2 to understand and quantify the run time differences,more » identifying key simulation settings and model features that have significant impacts on run time, and performing code profiling to identify which EnergyPlus subroutines consume the most amount of run time. This paper provides recommendations to improve EnergyPlus run time from the modeler?s perspective and adequate computing platforms. Suggestions of software code and architecture changes to improve EnergyPlus run time based on the code profiling results are also discussed.« less

Heuristic query optimization for query multiple table and multiple clausa on mobile finance application

NASA Astrophysics Data System (ADS)

Indrayana, I. N. E.; P, N. M. Wirasyanti D.; Sudiartha, I. KG

2018-01-01

Mobile application allow many users to access data from the application without being limited to space, space and time. Over time the data population of this application will increase. Data access time will cause problems if the data record has reached tens of thousands to millions of records.The objective of this research is to maintain the performance of data execution for large data records. One effort to maintain data access time performance is to apply query optimization method. The optimization used in this research is query heuristic optimization method. The built application is a mobile-based financial application using MySQL database with stored procedure therein. This application is used by more than one business entity in one database, thus enabling rapid data growth. In this stored procedure there is an optimized query using heuristic method. Query optimization is performed on a “Select” query that involves more than one table with multiple clausa. Evaluation is done by calculating the average access time using optimized and unoptimized queries. Access time calculation is also performed on the increase of population data in the database. The evaluation results shown the time of data execution with query heuristic optimization relatively faster than data execution time without using query optimization.

Evaluation of different time schedules in training with the Da Vinci simulator.

PubMed

Güldner, C; Orth, A; Dworschak, P; Diogo, I; Mandapathil, M; Teymoortash, A; Walliczek-Dworschak, U

2017-10-01

This prospective study analyzed the effect of different time schedules in training on the main performance outcomes: overall score, time to complete, and economy of motion. The study was performed on the da Vinci Skills Simulator from December 2014 to April 2016. Forty robotic novices were randomized into two groups of 20 participants, which trained in the same three exercises but with different intervals between their training sessions. Each group performed training in Peg Board 1 in their first week, Match Board 2 in their second week, and Ring and Rail 2 in their third week. On their last day, Needle Targeting and Energy Dissection 2, for which no previous training had been received, were performed. Regarding the different training intervals, group 1 trained each exercise six times in a row once a week. Group 2 performed their training once a day for 5 days. Technical performance parameters were recorded by the Mimics simulator software for further analysis. In addition, the participants were asked to fill out a questionnaire concerning the robotics training. Group 2 performed significantly better compared to group 1 in the main metrics in the more advanced exercises. For the easier exercises, the training frequency did not lead to significant differences in performance outcome. A significant skills gain was seen between the first and last training sessions for all exercises in both groups. Performance in the final exercise NT was significantly better in group 2 than group 1. Regarding ED 2, no difference was found between the two groups. As the training of group 2 led to significantly better outcomes, we suggest that, especially for advanced exercises, it seems to be more favorable to perform training every day for a short period than to train once a week six times in a row.

Real-time in-flight thrust calculation on a digital electronic engine control-equipped F100 engine in an F-15 airplane

NASA Technical Reports Server (NTRS)

Ray, R. J.; Myers, L. P.

1984-01-01

Computer algorithms which calculate in-flight engine and aircraft performance real-time are discussed. The first step was completed with the implementation of a real-time thrust calculation program on a digital electronic engine control (DEEC) equiped F100 engine in an F-15 aircraft. The in-flight thrust modifications that allow calculations to be performed in real-time, to compare results to predictions, are presented.

Rapid automatized naming (RAN) in children with ADHD: An ex-Gaussian analysis.

PubMed

Ryan, Matthew; Jacobson, Lisa A; Hague, Cole; Bellows, Alison; Denckla, Martha B; Mahone, E Mark

2017-07-01

Children with ADHD demonstrate increased frequent "lapses" in performance on tasks in which the stimulus presentation rate is externally controlled, leading to increased variability in response times. It is less clear whether these lapses are also evident during performance on self-paced tasks, e.g., rapid automatized naming (RAN), or whether RAN inter-item pause time variability uniquely predicts reading performance. A total of 80 children aged 9 to 14 years-45 children with attention-deficit/hyperactivity disorder (ADHD) and 35 typically developing (TD) children-completed RAN and reading fluency measures. RAN responses were digitally recorded for analyses. Inter-stimulus pause time distributions (excluding between-row pauses) were analyzed using traditional (mean, standard deviation [SD], coefficient of variation [CV]) and ex-Gaussian (mu, sigma, tau) methods. Children with ADHD were found to be significantly slower than TD children (p < .05) on RAN letter naming mean response time as well as on oral and silent reading fluency. RAN response time distributions were also significantly more variable (SD, tau) in children with ADHD. Hierarchical regression revealed that the exponential component (tau) of the letter-naming response time distribution uniquely predicted reading fluency in children with ADHD (p < .001, ΔR 2  = .16), even after controlling for IQ, basic reading, ADHD symptom severity and age. The findings suggest that children with ADHD (without word-level reading difficulties) manifest slowed performance on tasks of reading fluency; however, this "slowing" may be due in part to lapses from ongoing performance that can be assessed directly using ex-Gaussian methods that capture excessively long response times.

Impact of Machine Virtualization on Timing Precision for Performance-critical Tasks

NASA Astrophysics Data System (ADS)

Karpov, Kirill; Fedotova, Irina; Siemens, Eduard

2017-07-01

In this paper we present a measurement study to characterize the impact of hardware virtualization on basic software timing, as well as on precise sleep operations of an operating system. We investigated how timer hardware is shared among heavily CPU-, I/O- and Network-bound tasks on a virtual machine as well as on the host machine. VMware ESXi and QEMU/KVM have been chosen as commonly used examples of hypervisor- and host-based models. Based on statistical parameters of retrieved distributions, our results provide a very good estimation of timing behavior. It is essential for real-time and performance-critical applications such as image processing or real-time control.

Effects of major depression on moment-in-time work performance.

PubMed

Wang, Philip S; Beck, Arne L; Berglund, Pat; McKenas, David K; Pronk, Nicolaas P; Simon, Gregory E; Kessler, Ronald C

2004-10-01

Although major depression is thought to have substantial negative effects on work performance, the possibility of recall bias limits self-report studies of these effects. The authors used the experience sampling method to address this problem by collecting comparative data on moment-in-time work performance among service workers who were depressed and those who were not depressed. The group studied included 105 airline reservation agents and 181 telephone customer service representatives selected from a larger baseline sample; depressed workers were deliberately oversampled. Respondents were given pagers and experience sampling method diaries for each day of the study. A computerized autodialer paged respondents at random time points. When paged, respondents reported on their work performance in the diary. Moment-in-time work performance was assessed at five random times each day over a 7-day data collection period (35 data points for each respondent). Seven conditions (allergies, arthritis, back pain, headaches, high blood pressure, asthma, and major depression) occurred often enough in this group of respondents to be studied. Major depression was the only condition significantly related to decrements in both of the dimensions of work performance assessed in the diaries: task focus and productivity. These effects were equivalent to approximately 2.3 days absent because of sickness per depressed worker per month of being depressed. Previous studies based on days missed from work significantly underestimate the adverse economic effects associated with depression. Productivity losses related to depression appear to exceed the costs of effective treatment.

School-age adopted Chinese girls' behavioral adjustment, academic performance, and social skills: longitudinal results.

PubMed

Tan, Tony Xing

2009-04-01

Longitudinal data on 177 school-age adopted Chinese girls (Time 1: mean age = 8.92 years, SD = 1.76; Time 2: mean age = 11.18 years, SD = 1.79) were analyzed to determine their long-term outcomes in behavioral adjustment, academic performance (measured with the Child Behavior Checklist/6-18), and social skills (measured with the Social Skills Rating System) and how these outcomes were related to preadoption adversity. More than 90% of the girls were adopted at 24 months or younger (M = 19.25, SD = 21.67). Results revealed that over a 2-year period, there was a moderate to strong stability in the children's behavioral adjustment and academic performance. However, there was a significant increase in the number of children with deviant internalizing problems. At both times, higher degrees of preadoption adversity were related to more internalizing problems and poorer academic performance. Children who were adopted at older ages had poorer academic performance. Children who were older had a lower level of assertion and a higher level of responsibility. Children's attention problems at Time 1 mediated the effect of preadoption adversity on academic performance at Time 2. (c) 2009 APA, all rights reserved.

Medical student psychological distress and academic performance.

PubMed

Dendle, Claire; Baulch, Julie; Pellicano, Rebecca; Hay, Margaret; Lichtwark, Irene; Ayoub, Sally; Clarke, David M; Morand, Eric F; Kumar, Arunaz; Leech, Michelle; Horne, Kylie

2018-01-21

The impact of medical student psychological distress on academic performance has not been systematically examined. This study provided an opportunity to closely examine the potential impacts of workplace and study related stress factors on student's psychological distress and their academic performance during their first clinical year. This one-year prospective cohort study was performed at a tertiary hospital based medical school in Melbourne, Australia. Students completed a questionnaire at three time points during the year. The questionnaire included the validated Kessler psychological distress scale (K10) and the General Health Questionnaire-28 (GHQ-28), as well as items about sources of workplace stress. Academic outcome scores were aggregated and correlated with questionnaire results. One hundred and twenty six students participated; 126 (94.7%), 102 (76.7%), and 99 (74.4%) at time points one, two, and three, respectively. 33.1% reported psychological distress at time point one, increasing to 47.4% at time point three. There was no correlation between the K10 scores and academic performance. There was weak negative correlation between the GHQ-28 at time point three and academic performance. Keeping up to date with knowledge, need to do well and fear of negative feedback were the most common workplace stress factors. Poor correlation was noted between psychological distress and academic performance.

Eye gaze performance for children with severe physical impairments using gaze-based assistive technology-A longitudinal study.

PubMed

Borgestig, Maria; Sandqvist, Jan; Parsons, Richard; Falkmer, Torbjörn; Hemmingsson, Helena

2016-01-01

Gaze-based assistive technology (gaze-based AT) has the potential to provide children affected by severe physical impairments with opportunities for communication and activities. This study aimed to examine changes in eye gaze performance over time (time on task and accuracy) in children with severe physical impairments, without speaking ability, using gaze-based AT. A longitudinal study with a before and after design was conducted on 10 children (aged 1-15 years) with severe physical impairments, who were beginners to gaze-based AT at baseline. Thereafter, all children used the gaze-based AT in daily activities over the course of the study. Compass computer software was used to measure time on task and accuracy with eye selection of targets on screen, and tests were performed with the children at baseline, after 5 months, 9-11 months, and after 15-20 months. Findings showed that the children improved in time on task after 5 months and became more accurate in selecting targets after 15-20 months. This study indicates that these children with severe physical impairments, who were unable to speak, could improve in eye gaze performance. However, the children needed time to practice on a long-term basis to acquire skills needed to develop fast and accurate eye gaze performance.

The Effect of Two-dimensional and Stereoscopic Presentation on Middle School Students' Performance of Spatial Cognition Tasks

NASA Astrophysics Data System (ADS)

Price, Aaron; Lee, Hee-Sun

2010-02-01

We investigated whether and how student performance on three types of spatial cognition tasks differs when worked with two-dimensional or stereoscopic representations. We recruited nineteen middle school students visiting a planetarium in a large Midwestern American city and analyzed their performance on a series of spatial cognition tasks in terms of response accuracy and task completion time. Results show that response accuracy did not differ between the two types of representations while task completion time was significantly greater with the stereoscopic representations. The completion time increased as the number of mental manipulations of 3D objects increased in the tasks. Post-interviews provide evidence that some students continued to think of stereoscopic representations as two-dimensional. Based on cognitive load and cue theories, we interpret that, in the absence of pictorial depth cues, students may need more time to be familiar with stereoscopic representations for optimal performance. In light of these results, we discuss potential uses of stereoscopic representations for science learning.

Realizing the potential of empowerment: the impact of a feedback intervention on the performance of complex technology.

PubMed

Leach, D J; Jackson, P R; Wall, T D

2001-07-15

An empowerment initiative involving enhanced fault-management responsibility for operators of complex technology had not led to expected increases in performance, and investigations suggested that this was due to a lack of appropriate feedback. Thus, a feedback intervention was designed to provide specific, timely feedback on operator-correctable faults. It was hypothesized that the intervention would increase operator self-reliance in operating complex technology and promote system performance. Moreover, given the feedback was continuous from the point of intervention, it was predicted that gains would increase over time. Time series analysis of data on engineer call-outs (self-reliance) and machine utilization (performance) showed clear positive effects of the feedback intervention, with call-outs also showing progressive improvement. Self-report data showed no change over time in motivation, but an increase in knowledge dissemination and a reduction in the likelihood of making expensive mistakes. There were no detrimental effects on operator well being. Implications for theory and practice in the management of complex technology are discussed.

Impact of Age and Hearing Impairment on Work Performance during Long Working Hours

PubMed Central

Grossi, Nina R.; Kallus, K. Wolfgang

2018-01-01

Based on demographic prognoses, it must be assumed that a greater number of older workers will be found in the future labor market. How to deal with their possible age-related impairments of sensory functions, like hearing impairment and work performance during extended working time, has not been addressed explicitly until now. The study addresses this interplay. The study was performed on two consecutive days after normal working hours. The 55 participants had to “work” in the study at least three additional hours to simulate a situation of long working hours. The tested measures for (job) performance were: general attention, long-term selective attention, concentration, and reaction time. All of the investigated variables were taken at both days of the study (2 × 2 × 2 repeated measurement design). The results show effects for age, the interaction of hearing impairment and time of measurement, and effects of the measurement time. Older participants reacted slower than younger participants did. Furthermore, younger participants reacted more frequently in a correct way. Hearing impairment seems to have a negative impact especially on measures of false reactions, and therefore especially on measurement time 1. The results can be interpreted in a way that hearing-impaired participants are able to compensate their deficits over time. PMID:29315260

Impact of Age and Hearing Impairment on Work Performance during Long Working Hours.

PubMed

Wagner-Hartl, Verena; Grossi, Nina R; Kallus, K Wolfgang

2018-01-09

Based on demographic prognoses, it must be assumed that a greater number of older workers will be found in the future labor market. How to deal with their possible age-related impairments of sensory functions, like hearing impairment and work performance during extended working time, has not been addressed explicitly until now. The study addresses this interplay. The study was performed on two consecutive days after normal working hours. The 55 participants had to "work" in the study at least three additional hours to simulate a situation of long working hours. The tested measures for (job) performance were: general attention, long-term selective attention, concentration, and reaction time. All of the investigated variables were taken at both days of the study (2 × 2 × 2 repeated measurement design). The results show effects for age, the interaction of hearing impairment and time of measurement, and effects of the measurement time. Older participants reacted slower than younger participants did. Furthermore, younger participants reacted more frequently in a correct way. Hearing impairment seems to have a negative impact especially on measures of false reactions, and therefore especially on measurement time 1. The results can be interpreted in a way that hearing-impaired participants are able to compensate their deficits over time.

The effects of achene type and germination time on plant performance in the heterocarpic Anacyclus clavatus (Asteraceae).

PubMed

Afonso, Ana; Castro, Sílvia; Loureiro, João; Mota, Lucie; Cerca de Oliveira, José; Torices, Rubén

2014-05-01

• In heterocarpy, fruits with different morphologies have been associated with alternative strategies of dispersal, germination, dormancy, and seedling competitive ability. In heterocarpic species, it is common to find fruits with competitive or dispersal syndromes. The competitive advantage of nondispersing fruits has been frequently attributed to their larger size, but recent studies have suggested that this could also be mediated by germination time. The main objective of our study was to investigate which factor, fruit type or germination time, most affects plant performance and, consequently, competitive ability, using the heterocarpic species Anacyclus clavatus• To explore the effects of achene type and germination time on plant performance, we followed an innovative experimental approach including two experiments: one allowing for differences in germination time, and the other evaluating the effect of achene type alone by synchronizing germination time.• A significant effect of germination time on several postdispersal life-history traits was observed: Achenes that germinated earlier produced plants with higher biomass and reproductive effort. When germination time was controlled, no significant differences were observed in any of the traits.• The competitive advantage of achenes with different morphologies was mainly mediated by germination time and not by differences in size or other intrinsic traits. The consequences of these results are discussed in light of the dispersal-competition trade-off. Our experimental approach (i.e., the synchronization of germination time) revealed the importance of manipulative experiments for testing the effects of germination time on plant survival and performance. © 2014 Botanical Society of America, Inc.

Aspects of Motor Performance and Preacademic Learning.

ERIC Educational Resources Information Center

Feder, Katya; Kerr, Robert

1996-01-01

The Miller Assessment for Preschoolers (MAP) and a number/counting test were given to 50 4- and 5-year-olds. Low performance on counting was related to significantly slower average response time, overshoot movement time, and reaction time, indicating perceptual-motor difficulty. Low MAP scores indicated difficulty processing visual spatial…

Vis-A-Plan /visualize a plan/ management technique provides performance-time scale

NASA Technical Reports Server (NTRS)

Ranck, N. H.

1967-01-01

Vis-A-Plan is a bar-charting technique for representing and evaluating project activities on a performance-time basis. This rectilinear method presents the logic diagram of a project as a series of horizontal time bars. It may be used supplementary to PERT or independently.

FLAME: A platform for high performance computing of complex systems, applied for three case studies

DOE PAGES

Kiran, Mariam; Bicak, Mesude; Maleki-Dizaji, Saeedeh; ...

2011-01-01

FLAME allows complex models to be automatically parallelised on High Performance Computing (HPC) grids enabling large number of agents to be simulated over short periods of time. Modellers are hindered by complexities of porting models on parallel platforms and time taken to run large simulations on a single machine, which FLAME overcomes. Three case studies from different disciplines were modelled using FLAME, and are presented along with their performance results on a grid.

Multi-domain computerized cognitive training program improves performance of bookkeeping tasks: a matched-sampling active-controlled trial.

PubMed

Lampit, Amit; Ebster, Claus; Valenzuela, Michael

2014-01-01

Cognitive skills are important predictors of job performance, but the extent to which computerized cognitive training (CCT) can improve job performance in healthy adults is unclear. We report, for the first time, that a CCT program aimed at attention, memory, reasoning and visuo-spatial abilities can enhance productivity in healthy younger adults on bookkeeping tasks with high relevance to real-world job performance. 44 business students (77.3% female, mean age 21.4 ± 2.6 years) were assigned to either (a) 20 h of CCT, or (b) 20 h of computerized arithmetic training (active control) by a matched sampling procedure. Both interventions were conducted over a period of 6 weeks, 3-4 1-h sessions per week. Transfer of skills to performance on a 60-min paper-based bookkeeping task was measured at three time points-baseline, after 10 h and after 20 h of training. Repeated measures ANOVA found a significant Group X Time effect on productivity (F = 7.033, df = 1.745; 73.273, p = 0.003) with a significant interaction at both the 10-h (Relative Cohen's effect size = 0.38, p = 0.014) and 20-h time points (Relative Cohen's effect size = 0.40, p = 0.003). No significant effects were found on accuracy or on Conners' Continuous Performance Test, a measure of sustained attention. The results are discussed in reference to previous findings on the relationship between brain plasticity and job performance. Generalization of results requires further study.

The determination of dark adaptation time using electroretinography in conscious Miniature Schnauzer dogs

PubMed Central

Yu, Hyung-Ah; Jeong, Man-Bok; Park, Shin-Ae; Kim, Won-Tae; Kim, Se-Eun; Chae, Je-Min; Yi, Na-Young

2007-01-01

The optimal dark adaptation time of electroretinograms (ERG's) performed on conscious dogs were determined using a commercially available ERG unit with a contact lens electrode and a built-in light source (LED-electrode). The ERG recordings were performed on nine healthy Miniature Schnauzer dogs. The bilateral ERG's at seven different dark adaptation times at an intensity of 2.5 cd·s/m2 was performed. Signal averaging (4 flashes of light stimuli) was adopted to reduce electrophysiologic noise. As the dark adaptation time increased, a significant increase in the mean a-wave amplitudes was observed in comparison to base-line levels up to 10 min (p < 0.05). Thereafter, no significant differences in amplitude occured over the dark adaptation time. Moreover, at this time the mean amplitude was 60.30 ± 18.47 µV. However, no significant changes were observed for the implicit times of the a-wave. The implicit times and amplitude of the b-wave increased significantly up to 20 min of dark adaptation (p < 0.05). Beyond this time, the mean b-wave amplitudes was 132.92 ± 17.79 µV. The results of the present study demonstrate that, the optimal dark adaptation time when performing ERG's, should be at least 20 min in conscious Miniature Schnauzer dogs. PMID:17993756

The determination of dark adaptation time using electroretinography in conscious miniature Schnauzer dogs.

PubMed

Yu, Hyung-Ah; Jeong, Man-Bok; Park, Shin-Ae; Kim, Won-Tae; Kim, Se-Eun; Chae, Je-Min; Yi, Na-Young; Seo, Kang-Moon

2007-12-01

The optimal dark adaptation time of electroretinograms (ERG's) performed on conscious dogs were determined using a commercially available ERG unit with a contact lens electrode and a built-in light source (LED-electrode). The ERG recordings were performed on nine healthy Miniature Schnauzer dogs. The bilateral ERG's at seven different dark adaptation times at an intensity of 2.5 cd.s/m(2) was performed. Signal averaging (4 flashes of light stimuli) was adopted to reduce electrophysiologic noise. As the dark adaptation time increased, a significant increase in the mean a-wave amplitudes was observed in comparison to base-line levels up to 10 min (p < 0.05). Thereafter, no significant differences in amplitude occurred over the dark adaptation time. Moreover, at this time the mean amplitude was 60.30 +/- 18.47 microV. However, no significant changes were observed for the implicit times of the a-wave. The implicit times and amplitude of the b-wave increased significantly up to 20 min of dark adaptation (p < 0.05). Beyond this time, the mean b-wave amplitudes was 132.92 +/- 17.79 microV. The results of the present study demonstrate that, the optimal dark adaptation time when performing ERG's, should be at least 20 min in conscious Miniature Schnauzer dogs.

Memory shaped by age stereotypes over time.

PubMed

Levy, Becca R; Zonderman, Alan B; Slade, Martin D; Ferrucci, Luigi

2012-07-01

Previous studies showed that negative self-stereotypes detrimentally affect the cognitive performance of marginalized group members; however, these findings were confined to short-term experiments. In the present study, we considered whether stereotypes predicted memory over time, which had not been previously examined. We also considered whether self-relevance increased the influence of stereotypes on memory over time. Multiple waves of memory performance were analyzed using individual growth models. The sample consisted of 395 participants in the Baltimore Longitudinal Study of Aging. Those with more negative age stereotypes demonstrated significantly worse memory performance over 38 years than those with less negative age stereotypes, after adjusting for relevant covariates. The decline in memory performance for those aged 60 and above was 30.2% greater for the more negative age stereotype group than for the less negative age stereotype group. Also, the impact of age stereotypes on memory was significantly greater among those for whom the age stereotypes were self-relevant. This study shows that the adverse influence of negative self-stereotypes on cognitive performance is not limited to a short-term laboratory effect. Rather, the findings demonstrate, for the first time, that stereotypes also predict memory performance over an extended period in the community.

Effect of time step size and turbulence model on the open water hydrodynamic performance prediction of contra-rotating propellers

NASA Astrophysics Data System (ADS)

Wang, Zhan-zhi; Xiong, Ying

2013-04-01

A growing interest has been devoted to the contra-rotating propellers (CRPs) due to their high propulsive efficiency, torque balance, low fuel consumption, low cavitations, low noise performance and low hull vibration. Compared with the single-screw system, it is more difficult for the open water performance prediction because forward and aft propellers interact with each other and generate a more complicated flow field around the CRPs system. The current work focuses on the open water performance prediction of contra-rotating propellers by RANS and sliding mesh method considering the effect of computational time step size and turbulence model. The validation study has been performed on two sets of contra-rotating propellers developed by David W Taylor Naval Ship R & D center. Compared with the experimental data, it shows that RANS with sliding mesh method and SST k-ω turbulence model has a good precision in the open water performance prediction of contra-rotating propellers, and small time step size can improve the level of accuracy for CRPs with the same blade number of forward and aft propellers, while a relatively large time step size is a better choice for CRPs with different blade numbers.

The Impact of Students' Temporal Perspectives on Time-on-Task and Learning Performance in Game Based Learning

ERIC Educational Resources Information Center

Romero, Margarida; Usart, Mireia

2013-01-01

The use of games for educational purposes has been considered as a learning methodology that attracts the students' attention and may allow focusing individuals on the learning activity through the [serious games] SG game dynamic. Based on the hypothesis that students' Temporal Perspective has an impact on learning performance and time-on-task,…

Pilot age and expertise predict flight simulator performance: a 3-year longitudinal study.

PubMed

Taylor, Joy L; Kennedy, Quinn; Noda, Art; Yesavage, Jerome A

2007-02-27

Expert knowledge may compensate for age-related declines in basic cognitive and sensory-motor abilities in some skill domains. We investigated the influence of age and aviation expertise (indexed by Federal Aviation Administration pilot ratings) on longitudinal flight simulator performance. Over a 3-year period, 118 general aviation pilots aged 40 to 69 years were tested annually, in which their flight performance was scored in terms of 1) executing air-traffic controller communications; 2) traffic avoidance; 3) scanning cockpit instruments; 4) executing an approach to landing; and 5) a flight summary score. More expert pilots had better flight summary scores at baseline and showed less decline over time. Secondary analyses revealed that expertise effects were most evident in the accuracy of executing aviation communications, the measure on which performance declined most sharply over time. Regarding age, even though older pilots initially performed worse than younger pilots, over time older pilots showed less decline in flight summary scores than younger pilots. Secondary analyses revealed that the oldest pilots did well over time because their traffic avoidance performance improved more vs younger pilots. These longitudinal findings support previous cross-sectional studies in aviation as well as non-aviation domains, which demonstrated the advantageous effect of prior experience and specialized expertise on older adults' skilled cognitive performances.

Pilot age and expertise predict flight simulator performance

PubMed Central

Kennedy, Quinn; Noda, Art; Yesavage, Jerome A.

2010-01-01

Background Expert knowledge may compensate for age-related declines in basic cognitive and sensory-motor abilities in some skill domains. We investigated the influence of age and aviation expertise (indexed by Federal Aviation Administration pilot ratings) on longitudinal flight simulator performance. Methods Over a 3-year period, 118 general aviation pilots aged 40 to 69 years were tested annually, in which their flight performance was scored in terms of 1) executing air-traffic controller communications; 2) traffic avoidance; 3) scanning cockpit instruments; 4) executing an approach to landing; and 5) a flight summary score. Results More expert pilots had better flight summary scores at baseline and showed less decline over time. Secondary analyses revealed that expertise effects were most evident in the accuracy of executing aviation communications, the measure on which performance declined most sharply over time. Regarding age, even though older pilots initially performed worse than younger pilots, over time older pilots showed less decline in flight summary scores than younger pilots. Secondary analyses revealed that the oldest pilots did well over time because their traffic avoidance performance improved more vs younger pilots. Conclusions These longitudinal findings support previous cross-sectional studies in aviation as well as non-aviation domains, which demonstrated the advantageous effect of prior experience and specialized expertise on older adults’ skilled cognitive performances. PMID:17325270

The effects of reduced oxygen and of carbon monoxide on performance in a mouse pole-jump apparatus

NASA Technical Reports Server (NTRS)

Cagliostro, D. E.; Islas, A.

1982-01-01

The effects on reaction time and behavior were studied for exposure to reduced oxygen concentrations in the presence and absence of carbon monoxide. Tests were run with Swiss Webster mice in a pole-jump apparatus. The results show that reaction times increase gradually with a decrease in oxygen (O2) to 10 percent O2. Below 10 percent O2 reaction times increase dramatically and performance is degraded almost immediately. At carbon monoxide (CO) concentrations of 500 ppm and reduced O2 levels, reaction times are increased even more. At CO concentrations of 1000 ppm, performance is nearly completely degraded even without reduced oxygen levels.

Modeling reciprocal team cohesion-performance relationships, as impacted by shared leadership and members' competence.

PubMed

Mathieu, John E; Kukenberger, Michael R; D'Innocenzo, Lauren; Reilly, Greg

2015-05-01

Despite the lengthy history of team cohesion-performance research, little is known about their reciprocal relationships over time. Using meta-analysis, we synthesize findings from 17 CLP design studies, and analyze their results using SEM. Results support that team cohesion and performance are related reciprocally with each other over time. We then used longitudinal data from 205 members of 57 student teams who competed in a complex business simulation over 10 weeks, to test: (a) whether team cohesion and performance were related reciprocally over multiple time periods, (b) the relative magnitude of those relationships, and (c) whether they were stable over time. We also considered the influence of team members' academic competence and degree of shared leadership on these dynamics. As anticipated, cohesion and performance were related positively, and reciprocally, over time. However, the cohesion → performance relationship was significantly higher than the performance → cohesion relationship. Moreover, the cohesion → performance relationship grew stronger over time whereas the performance → cohesion relationship remained fairly consistent over time. As expected, shared leadership related positively to team cohesion but not directly to their performance; whereas average team member academic competence related positively to team performance but was unrelated to team cohesion. Finally, we conducted and report a replication using a second sample of students competing in a business simulation. Our earlier substantive relationships were mostly replicated, and we illustrated the dynamic temporal properties of shared leadership. We discuss these findings in terms of theoretical importance, applied implications, and directions for future research. (c) 2015 APA, all rights reserved.

Physical education, school physical activity, school sports and academic performance

PubMed Central

Trudeau, François; Shephard, Roy J

2008-01-01

Background The purpose of this paper is to review relationships of academic performance and some of its determinants to participation in school-based physical activities, including physical education (PE), free school physical activity (PA) and school sports. Methods Linkages between academic achievement and involvement in PE, school PA and sport programmes have been examined, based on a systematic review of currently available literature, including a comprehensive search of MEDLINE (1966 to 2007), PSYCHINFO (1974 to 2007), SCHOLAR.GOOGLE.COM, and ERIC databases. Results Quasi-experimental data indicate that allocating up to an additional hour per day of curricular time to PA programmes does not affect the academic performance of primary school students negatively, even though the time allocated to other subjects usually shows a corresponding reduction. An additional curricular emphasis on PE may result in small absolute gains in grade point average (GPA), and such findings strongly suggest a relative increase in performance per unit of academic teaching time. Further, the overwhelmingly majority of such programmes have demonstrated an improvement in some measures of physical fitness (PF). Cross-sectional observations show a positive association between academic performance and PA, but PF does not seem to show such an association. PA has positive influences on concentration, memory and classroom behaviour. Data from quasi-experimental studies find support in mechanistic experiments on cognitive function, pointing to a positive relationship between PA and intellectual performance. Conclusion Given competent providers, PA can be added to the school curriculum by taking time from other subjects without risk of hindering student academic achievement. On the other hand, adding time to "academic" or "curricular" subjects by taking time from physical education programmes does not enhance grades in these subjects and may be detrimental to health. PMID:18298849

Supplier Selection based on the Performance by using PROMETHEE Method

NASA Astrophysics Data System (ADS)

Sinaga, T. S.; Siregar, K.

2017-03-01

Generally, companies faced problem to identify vendors that can provide excellent service in availability raw material and on time delivery. The performance of suppliers in a company have to be monitored to ensure the availability to fulfill the company needs. This research is intended to explain how to assess suppliers to improve manufacturing performance. The criteria that considered in evaluating suppliers is criteria of Dickson. There are four main criteria which further split into seven sub-criteria, namely compliance with accuracy, consistency, on-time delivery, right quantity order, flexibility and negotiation, timely of order confirmation, and responsiveness. This research uses PROMETHEE methodology in assessing the supplier performances and obtaining a selected supplier as the best one that shown from the degree of alternative comparison preference between suppliers.

The effect of processing code, response modality and task difficulty on dual task performance and subjective workload in a manual system

NASA Technical Reports Server (NTRS)

Liu, Yili; Wickens, Christopher D.

1987-01-01

This paper reports on the first experiment of a series studying the effect of task structure and difficulty demand on time-sharing performance and workload in both automated and corresponding manual systems. The experimental task involves manual control time-shared with spatial and verbal decisions tasks of two levels of difficulty and two modes of response (voice or manual). The results provide strong evidence that tasks and processes competing for common processing resources are time shared less effecively and have higher workload than tasks competing for separate resources. Subjective measures and the structure of multiple resources are used in conjunction to predict dual task performance. The evidence comes from both single-task and from dual-task performance.

Remember to do: insomnia versus control groups in a prospective memory task.

PubMed

Fabbri, Marco; Tonetti, Lorenzo; Martoni, Monica; Natale, Vincenzo

2015-01-01

Primary insomnia is characterized by difficulty in falling asleep and/or remaining asleep, by early morning awakening and/or nonrestorative sleep, and resultant daytime dysfunction in the absence of specific physical, mental, or substance-related causes. However, the studies on daytime cognitive functioning of insomnia patients report inconclusive results. This retrospective study aimed to compare the performance of insomnia patients (N = 54) to that of controls (N = 113) in a naturalistic prospective memory task. Task performance was defined by the percentage of times the event-marker button of an actigraph was pressed, at lights-off time and at wake-up time. The performance pattern in the prospective memory task was similar in both groups. In addition, the task was performed better at lights-off time than at wake-up time regardless of group. Post-hoc subgroup analysis showed that there were more insomnia patients who performed the task perfectly (i.e., 100%) than controls. Performance at wake-up time was significantly correlated to objective sleep quality (i.e., sleep efficiency) only in insomnia patients.

The effectiveness of incorporating a real-time oculometer system in a commercial flight training program

NASA Technical Reports Server (NTRS)

Jones, D. H.; Coates, G. D.; Kirby, R. H.

1982-01-01

The effectiveness on pilot and trainee performance and scanning behavior of incorporating a real time oculometer system in a commerical flight training program was assessed. Trainees received simulator training in pairs requiring the trainees to alternate the order of training within a session. The 'third day phenomenon' of performance decrement was investigated, including the role of order of training on performance.

Evaluation of emergency department performance - a systematic review on recommended performance and quality-in-care measures.

PubMed

Sørup, Christian Michel; Jacobsen, Peter; Forberg, Jakob Lundager

2013-08-09

Evaluation of emergency department (ED) performance remains a difficult task due to the lack of consensus on performance measures that reflects high quality, efficiency, and sustainability. To describe, map, and critically evaluate which performance measures that the published literature regard as being most relevant in assessing overall ED performance. Following the PRISMA guidelines, a systematic literature review of review articles reporting accentuated ED performance measures was conducted in the databases of PubMed, Cochrane Library, and Web of Science. Study eligibility criteria includes: 1) the main purpose was to discuss, analyse, or promote performance measures best reflecting ED performance, 2) the article was a review article, and 3) the article reported macro-level performance measures, thus reflecting an overall departmental performance level. A number of articles addresses this study's objective (n = 14 of 46 unique hits). Time intervals and patient-related measures were dominant in the identified performance measures in review articles from US, UK, Sweden and Canada. Length of stay (LOS), time between patient arrival to initial clinical assessment, and time between patient arrivals to admission were highlighted by the majority of articles. Concurrently, "patients left without being seen" (LWBS), unplanned re-attendance within a maximum of 72 hours, mortality/morbidity, and number of unintended incidents were the most highlighted performance measures that related directly to the patient. Performance measures related to employees were only stated in two of the 14 included articles. A total of 55 ED performance measures were identified. ED time intervals were the most recommended performance measures followed by patient centeredness and safety performance measures. ED employee related performance measures were rarely mentioned in the investigated literature. The study's results allow for advancement towards improved performance measurement and standardised assessment across EDs.

Evaluating Alerting and Guidance Performance of a UAS Detect-And-Avoid System

NASA Technical Reports Server (NTRS)

Lee, Seung Man; Park, Chunki; Thipphavong, David P.; Isaacson, Douglas R.; Santiago, Confesor

2016-01-01

A key challenge to the routine, safe operation of unmanned aircraft systems (UAS) is the development of detect-and-avoid (DAA) systems to aid the UAS pilot in remaining "well clear" of nearby aircraft. The goal of this study is to investigate the effect of alerting criteria and pilot response delay on the safety and performance of UAS DAA systems in the context of routine civil UAS operations in the National Airspace System (NAS). A NAS-wide fast-time simulation study was conducted to assess UAS DAA system performance with a large number of encounters and a broad set of DAA alerting and guidance system parameters. Three attributes of the DAA system were controlled as independent variables in the study to conduct trade-off analyses: UAS trajectory prediction method (dead-reckoning vs. intent-based), alerting time threshold (related to predicted time to LoWC), and alerting distance threshold (related to predicted Horizontal Miss Distance, or HMD). A set of metrics, such as the percentage of true positive, false positive, and missed alerts, based on signal detection theory and analysis methods utilizing the Receiver Operating Characteristic (ROC) curves were proposed to evaluate the safety and performance of DAA alerting and guidance systems and aid development of DAA system performance standards. The effect of pilot response delay on the performance of DAA systems was evaluated using a DAA alerting and guidance model and a pilot model developed to support this study. A total of 18 fast-time simulations were conducted with nine different DAA alerting threshold settings and two different trajectory prediction methods, using recorded radar traffic from current Visual Flight Rules (VFR) operations, and supplemented with DAA-equipped UAS traffic based on mission profiles modeling future UAS operations. Results indicate DAA alerting distance threshold has a greater effect on DAA system performance than DAA alerting time threshold or ownship trajectory prediction method. Further analysis on the alert lead time (time in advance of predicted loss of well clear at which a DAA alert is first issued) indicated a strong positive correlation between alert lead time and DAA system performance (i.e. the ability of the UAS pilot to maneuver the unmanned aircraft to remain well clear). While bigger distance thresholds had beneficial effects on alert lead time and missed alert rate, it also generated a higher rate of false alerts. In the design and development of DAA alerting and guidance systems, therefore, the positive and negative effects of false alerts and missed alerts should be carefully considered to achieve acceptable alerting system performance by balancing false and missed alerts. The results and methodology presented in this study are expected to help stakeholders, policymakers and standards committees define the appropriate setting of DAA system parameter thresholds for UAS that ensure safety while minimizing operational impacts to the NAS and equipage requirements for its users before DAA operational performance standards can be finalized.

Timely Reperfusion in Stroke and Myocardial Infarction Is Not Correlated: An Opportunity for Better Coordination of Acute Care.

PubMed

Sauser Zachrison, Kori; Levine, Deborah A; Fonarow, Gregg C; Bhatt, Deepak L; Cox, Margueritte; Schulte, Phillip; Smith, Eric E; Suter, Robert E; Xian, Ying; Schwamm, Lee H

2017-03-01

Timely reperfusion is critical in acute ischemic stroke (AIS) and ST-segment-elevation myocardial infarction (STEMI). The degree to which hospital performance is correlated on emergent STEMI and AIS care is unknown. Primary objective of this study was to determine whether there was a positive correlation between hospital performance on door-to-balloon (D2B) time for STEMI and door-to-needle (DTN) time for AIS, with and without controlling for patient and hospital differences. Prospective study of all hospitals in both Get With The Guidelines-Stroke and Get With The Guidelines-Coronary Artery Disease from 2006 to 2009 and treating ≥10 patients. We compared hospital-level DTN time and D2B time using Spearman rank correlation coefficients and hierarchical linear regression modeling. There were 43 hospitals with 1976 AIS and 59 823 STEMI patients. Hospitals' DTN times for AIS did not correlate with D2B times for STEMI (ρ=-0.09; P =0.55). There was no correlation between hospitals' proportion of eligible patients treated within target time windows for AIS and STEMI (median DTN time <60 minutes: 21% [interquartile range, 11-30]; median D2B time <90 minutes: 68% [interquartile range, 62-79]; ρ=-0.14; P =0.36). The lack of correlation between hospitals' DTN and D2B times persisted after risk adjustment. We also correlated hospitals' DTN time and D2B time data from 2013 to 2014 using Get With The Guidelines (DTN time) and Hospital Compare (D2B time). From 2013 to 2014, hospitals' DTN time performance in Get With The Guidelines was not correlated with D2B time performance in Hospital Compare (n=546 hospitals). We found no correlation between hospitals' observed or risk-adjusted DTN and D2B times. Opportunities exist to improve hospitals' performance of time-critical care processes for AIS and STEMI in a coordinated approach. © 2017 American Heart Association, Inc.

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

NASA Astrophysics Data System (ADS)

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

2014-05-01

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

ACT Profile Report: State. Graduating Class 2012. New Hampshire

ERIC Educational Resources Information Center

ACT, Inc., 2012

2012-01-01

This report provides information about the performance of New Hampshire's 2012 graduating seniors who took the ACT as sophomores, juniors, or seniors; and self-reported at the time of testing that they were scheduled to graduate in 2012 and tested under standard time conditions. This report focuses on: (1) Performance: student test performance in…

Correlating Trainee Attributes to Performance in 3D CAD Training

ERIC Educational Resources Information Center

Hamade, Ramsey F.; Artail, Hassan A.; Sikstrom, Sverker

2007-01-01

Purpose: The purpose of this exploratory study is to identify trainee attributes relevant for development of skills in 3D computer-aided design (CAD). Design/methodology/approach: Participants were trained to perform cognitive tasks of comparable complexity over time. Performance data were collected on the time needed to construct test models, and…

[Effects on performance of high-speed dental handpieces subjected to autoclaving].

PubMed

Deng, Xiao-hong; Sun, Zheng; Su, Jing; Qiao, Hong; Xiao, Xiao

2006-07-01

To investigate the effects on performances of high-speed dental handpieces subjected to autoclaving. The method of trial used to evaluate the effect of autoclaving included that ten chemical and ten biological indicators were arranged in each trial group being set by one sort of temperature and sterilization time. The range of temperature was from 100 degrees C to 134 degrees C and the sterilization time was from 1 to 45 minutes. The reliability of autoclaving was evaluated by the result of chemical indicator and the endospores of Bacillus stearothermophilus subjected to autoclaving. Ten newly imported and ten new domestic dental handpieces in two different brands were used to carry out this trial. The effects produced by autoclaving on performances of dental handpieces subjected to different type autoclaves were evaluated by some parameters. The eligible outcome in killing test of the 221 sterilized dental handpieces proved that the sterilization effect of autoclaving on dental handpieces was reliable. The chemical indicators showed that under the condition of 121 degrees C it needed 20 minutes to reach sterilization standard in the inner package and only 15 minutes on the outer package, and under the condition of 134 degrees C it took 4 minutes to reach sterilization standard in the inner package while only 2 minutes on the outer package. This outcome proved that material with package was more time-consuming than that without package during autoclaving. Autoclaving has positive effects on the performance of dental handpieces, while the autoclave with less-time full sterilization cycle has less effect on it. The performance of dental handpieces sterilized by the autoclave with 6-minute full sterilization cycle might be restorable within certain times of sterilization cycle. The sterilization effect of autoclaving is reliable. In order to reduce the influence on the performance of dental handpieces subjected to autoclaving, it should be reasonable to use the autoclave by which a full sterilization cycle might take less time and no use of package.

Factors that influence standard automated perimetry test results in glaucoma: test reliability, technician experience, time of day, and season.

PubMed

Junoy Montolio, Francisco G; Wesselink, Christiaan; Gordijn, Marijke; Jansonius, Nomdo M

2012-10-09

To determine the influence of several factors on standard automated perimetry test results in glaucoma. Longitudinal Humphrey field analyzer 30-2 Swedish interactive threshold algorithm data from 160 eyes of 160 glaucoma patients were used. The influence of technician experience, time of day, and season on the mean deviation (MD) was determined by performing linear regression analysis of MD against time on a series of visual fields and subsequently performing a multiple linear regression analysis with the MD residuals as dependent variable and the factors mentioned above as independent variables. Analyses were performed with and without adjustment for the test reliability (fixation losses and false-positive and false-negative answers) and with and without stratification according to disease stage (baseline MD). Mean follow-up was 9.4 years, with on average 10.8 tests per patient. Technician experience, time of day, and season were associated with the MD. Approximately 0.2 dB lower MD values were found for inexperienced technicians (P < 0.001), tests performed after lunch (P < 0.001), and tests performed in the summer or autumn (P < 0.001). The effects of time of day and season appeared to depend on disease stage. Independent of these effects, the percentage of false-positive answers strongly influenced the MD with a 1 dB increase in MD per 10% increase in false-positive answers. Technician experience, time of day, season, and the percentage of false-positive answers have a significant influence on the MD of standard automated perimetry.

Deficits in Coordinative Bimanual Timing Precision in Children With Specific Language Impairment

PubMed Central

Goffman, Lisa; Zelaznik, Howard N.

2017-01-01

Purpose Our objective was to delineate components of motor performance in specific language impairment (SLI); specifically, whether deficits in timing precision in one effector (unimanual tapping) and in two effectors (bimanual clapping) are observed in young children with SLI. Method Twenty-seven 4- to 5-year-old children with SLI and 21 age-matched peers with typical language development participated. All children engaged in a unimanual tapping and a bimanual clapping timing task. Standard measures of language and motor performance were also obtained. Results No group differences in timing variability were observed in the unimanual tapping task. However, compared with typically developing peers, children with SLI were more variable in their timing precision in the bimanual clapping task. Nine of the children with SLI performed greater than 1 SD below the mean on a standardized motor assessment. The children with low motor performance showed the same profile as observed across all children with SLI, with unaffected unimanual and impaired bimanual timing precision. Conclusions Although unimanual timing is unaffected, children with SLI show a deficit in timing that requires bimanual coordination. We propose that the timing deficits observed in children with SLI are associated with the increased demands inherent in bimanual performance. PMID:28174821

Media processors using a new microsystem architecture designed for the Internet era

NASA Astrophysics Data System (ADS)

Wyland, David C.

1999-12-01

The demands of digital image processing, communications and multimedia applications are growing more rapidly than traditional design methods can fulfill them. Previously, only custom hardware designs could provide the performance required to meet the demands of these applications. However, hardware design has reached a crisis point. Hardware design can no longer deliver a product with the required performance and cost in a reasonable time for a reasonable risk. Software based designs running on conventional processors can deliver working designs in a reasonable time and with low risk but cannot meet the performance requirements. What is needed is a media processing approach that combines very high performance, a simple programming model, complete programmability, short time to market and scalability. The Universal Micro System (UMS) is a solution to these problems. The UMS is a completely programmable (including I/O) system on a chip that combines hardware performance with the fast time to market, low cost and low risk of software designs.

On Extended Dissipativity of Discrete-Time Neural Networks With Time Delay.

PubMed

Feng, Zhiguang; Zheng, Wei Xing

2015-12-01

In this brief, the problem of extended dissipativity analysis for discrete-time neural networks with time-varying delay is investigated. The definition of extended dissipativity of discrete-time neural networks is proposed, which unifies several performance measures, such as the H∞ performance, passivity, l2 - l∞ performance, and dissipativity. By introducing a triple-summable term in Lyapunov function, the reciprocally convex approach is utilized to bound the forward difference of the triple-summable term and then the extended dissipativity criterion for discrete-time neural networks with time-varying delay is established. The derived condition guarantees not only the extended dissipativity but also the stability of the neural networks. Two numerical examples are given to demonstrate the reduced conservatism and effectiveness of the obtained results.

Time management training and perceived control of time at work.

PubMed

Häfner, Alexander; Stock, Armin

2010-01-01

The purpose of the present study was to examine the effects of time management training, which was based on psychological theory and research, on perceived control of time, perceived stress, and performance at work. The authors randomly assigned 71 employees to a training group (n = 35) or a waiting-list control group (n = 36). As hypothesized, time management training led to an increase in perceived control of time and a decrease in perceived stress. Time management training had no impact on different performance indicators. In particular, the authors explored the use and the perceived usefulness of the techniques taught. Participants judged the taught techniques as useful, but there were large differences concerning the actual use of the various techniques.

Automated selection of brain regions for real-time fMRI brain-computer interfaces

NASA Astrophysics Data System (ADS)

Lührs, Michael; Sorger, Bettina; Goebel, Rainer; Esposito, Fabrizio

2017-02-01

Objective. Brain-computer interfaces (BCIs) implemented with real-time functional magnetic resonance imaging (rt-fMRI) use fMRI time-courses from predefined regions of interest (ROIs). To reach best performances, localizer experiments and on-site expert supervision are required for ROI definition. To automate this step, we developed two unsupervised computational techniques based on the general linear model (GLM) and independent component analysis (ICA) of rt-fMRI data, and compared their performances on a communication BCI. Approach. 3 T fMRI data of six volunteers were re-analyzed in simulated real-time. During a localizer run, participants performed three mental tasks following visual cues. During two communication runs, a letter-spelling display guided the subjects to freely encode letters by performing one of the mental tasks with a specific timing. GLM- and ICA-based procedures were used to decode each letter, respectively using compact ROIs and whole-brain distributed spatio-temporal patterns of fMRI activity, automatically defined from subject-specific or group-level maps. Main results. Letter-decoding performances were comparable to supervised methods. In combination with a similarity-based criterion, GLM- and ICA-based approaches successfully decoded more than 80% (average) of the letters. Subject-specific maps yielded optimal performances. Significance. Automated solutions for ROI selection may help accelerating the translation of rt-fMRI BCIs from research to clinical applications.

Sequence learning in Parkinson's disease: Focusing on action dynamics and the role of dopaminergic medication.

PubMed

Ruitenberg, Marit F L; Duthoo, Wout; Santens, Patrick; Seidler, Rachael D; Notebaert, Wim; Abrahamse, Elger L

2016-12-01

Previous studies on movement sequence learning in Parkinson's disease (PD) have produced mixed results. A possible explanation for the inconsistent findings is that some studies have taken dopaminergic medication into account while others have not. Additionally, in previous studies the response modalities did not allow for an investigation of the action dynamics of sequential movements as they unfold over time. In the current study we investigated sequence learning in PD by specifically considering the role of medication status in a sequence learning task where mouse movements were performed. The focus on mouse movements allowed us to examine the action dynamics of sequential movement in terms of initiation time, movement time, movement accuracy, and velocity. PD patients performed the sequence learning task once on their regular medication, and once after overnight withdrawal from their medication. Results showed that sequence learning as reflected in initiation times was impaired when PD patients performed the task ON medication compared to OFF medication. In contrast, sequence learning as reflected in the accuracy of movement trajectories was enhanced when performing the task ON compared to OFF medication. Our findings suggest that while medication enhances execution processes of movement sequence learning, it may at the same time impair planning processes that precede actual execution. Overall, the current study extends earlier findings on movement sequence learning in PD by differentiating between various components of performance, and further refines previous dopamine overdose effects in sequence learning. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quiet eye training improves surgical knot tying more than traditional technical training: a randomized controlled study.

PubMed

Causer, Joe; Harvey, Adrian; Snelgrove, Ryan; Arsenault, Gina; Vickers, Joan N

2014-08-01

We examined the effectiveness of technical training (TT) and quiet eye training (QE) on the performance of one-handed square knot tying in surgical residents. Twenty surgical residents were randomly assigned to the 2 groups and completed pretest, training, retention, and transfer tests. Participants wore a mobile eye tracker that simultaneously recorded their gaze and hand movements. Dependent variables were knot tying performance (%), QE duration (%), number of fixations, total movement time (s), and hand movement phase time (s). The QE training group had significantly higher performance scores, a longer QE duration, fewer fixations, faster total knot tying times, and faster movement phase times compared with the TT group. The QE group maintained performance in the transfer test, whereas the TT group significantly decreased performance from retention to transfer. QE training significantly improved learning, retention, and transfer of surgical knot tying compared with a traditional technical approach. Both performance effectiveness (performance outcome) and movement efficiency (hand movement times) were improved using QE modeling, instruction, and feedback. Copyright © 2014 Elsevier Inc. All rights reserved.

Design Alternatives to Improve Access Time Performance of Disk Drives Under DOS and UNIX

NASA Astrophysics Data System (ADS)

Hospodor, Andy

For the past 25 years, improvements in CPU performance have overshadowed improvements in the access time performance of disk drives. CPU performance has been slanted towards greater instruction execution rates, measured in millions of instructions per second (MIPS). However, the slant for performance of disk storage has been towards capacity and corresponding increased storage densities. The IBM PC, introduced in 1982, processed only a fraction of a MIP. Follow-on CPUs, such as the 80486 and 80586, sported 5-10 MIPS by 1992. Single user PCs and workstations, with one CPU and one disk drive, became the dominant application, as implied by their production volumes. However, disk drives did not enjoy a corresponding improvement in access time performance, although the potential still exists. The time to access a disk drive improves (decreases) in two ways: by altering the mechanical properties of the drive or by adding cache to the drive. This paper explores the improvement to access time performance of disk drives using cache, prefetch, faster rotation rates, and faster seek acceleration.

An Occupational Performance Test Validation Program for Fire Fighters at the Kennedy Space Center

NASA Technical Reports Server (NTRS)

Schonfeld, Brian R.; Doerr, Donald F.; Convertino, Victor A.

1990-01-01

We evaluated performance of a modified Combat Task Test (CTT) and of standard fitness tests in 20 male subjects to assess the prediction of occupational performance standards for Kennedy Space Center fire fighters. The CTT consisted of stair-climbing, a chopping simulation, and a victim rescue simulation. Average CTT performance time was 3.61 +/- 0.25 min (SEM) and all CTT tasks required 93% to 97% maximal heart rate. By using scores from the standard fitness tests, a multiple linear regression model was fitted to each parameter: the stairclimb (r(exp 2) = .905, P less than .05), the chopping performance time (r(exp 2) = .582, P less than .05), the victim rescue time (r(exp 2) = .218, P = not significant), and the total performance time (r(exp 2) = .769, P less than .05). Treadmill time was the predominant variable, being the major predictor in two of four models. These results indicated that standardized fitness tests can predict performance on some CTT tasks and that test predictors were amenable to exercise training.

Effect of Tai Chi Training on Dual-Tasking Performance That Involves Stepping Down among Stroke Survivors: A Pilot Study.

PubMed

Chan, Wing-Nga; Tsang, William Wai-Nam

2017-01-01

Descending stairs demands attention and neuromuscular control, especially with dual-tasking. Studies have demonstrated that stroke often degrades a survivor's ability to descend stairs. Tai Chi has been shown to improve dual-tasking performance of healthy older adults, but no such study has been conducted in stroke survivors. This study investigated the effect of Tai Chi training on dual-tasking performance that involved stepping down and compared it with that of conventional exercise among stroke survivors. Subjects were randomized into Tai Chi ( n = 9), conventional exercise ( n = 8), and control ( n = 9) groups. Those in the former two groups received 12-week training. Assessments included auditory Stroop test, stepping down test, and dual-tasking test involving both simultaneously. They were evaluated before training (time-1), after training (time-2), and one month after training (time-3). Tai Chi group showed significant improvement in the auditory Stroop test from time-1 to time-3 and the performance was significantly better than that of the conventional exercise group in time-3. No significant effect was found in the stepping down task or dual-tasking in the control group. These results suggest a beneficial effect of Tai Chi training on cognition among stroke survivors without compromising physical task performance in dual-tasking. The effect was better than the conventional exercise group. Nevertheless, further research with a larger sample is warranted.

Variability in reaction time performance of younger and older adults.

PubMed

Hultsch, David F; MacDonald, Stuart W S; Dixon, Roger A

2002-03-01

Age differences in three basic types of variability were examined: variability between persons (diversity), variability within persons across tasks (dispersion), and variability within persons across time (inconsistency). Measures of variability were based on latency performance from four measures of reaction time (RT) performed by a total of 99 younger adults (ages 17--36 years) and 763 older adults (ages 54--94 years). Results indicated that all three types of variability were greater in older compared with younger participants even when group differences in speed were statistically controlled. Quantile-quantile plots showed age and task differences in the shape of the inconsistency distributions. Measures of within-person variability (dispersion and inconsistency) were positively correlated. Individual differences in RT inconsistency correlated negatively with level of performance on measures of perceptual speed, working memory, episodic memory, and crystallized abilities. Partial set correlation analyses indicated that inconsistency predicted cognitive performance independent of level of performance. The results indicate that variability of performance is an important indicator of cognitive functioning and aging.

CoR-MAC: Contention over Reservation MAC Protocol for Time-Critical Services in Wireless Body Area Sensor Networks

PubMed Central

Yu, Jeongseok; Park, Laihyuk; Park, Junho; Cho, Sungrae; Keum, Changsup

2016-01-01

Reserving time slots for urgent data, such as life-critical information, seems to be very attractive to guarantee their deadline requirements in wireless body area sensor networks (WBASNs). On the other hand, this reservation imposes a negative impact on performance for the utilization of a channel. This paper proposes a new channel access scheme referred to as the contention over reservation MAC (CoR-MAC) protocol for time-critical services in wireless body area sensor networks. CoR-MAC uses the dual reservation; if the reserved time slots are known to be vacant, other nodes can access the time slots by contention-based reservation to maximize the utilization of a channel and decrease the delay of the data. To measure the effectiveness of the proposed scheme against IEEE 802.15.4 and IEEE 802.15.6, we evaluated their performances with various performance indexes. The CoR-MAC showed 50% to 850% performance improvement in terms of the delay of urgent and time-critical data according to the number of nodes. PMID:27171085

Simulator study of the effect of visual-motion time delays on pilot tracking performance with an audio side task

NASA Technical Reports Server (NTRS)

Riley, D. R.; Miller, G. K., Jr.

1978-01-01

The effect of time delay was determined in the visual and motion cues in a flight simulator on pilot performance in tracking a target aircraft that was oscillating sinusoidally in altitude only. An audio side task was used to assure the subject was fully occupied at all times. The results indicate that, within the test grid employed, about the same acceptable time delay (250 msec) was obtained for a single aircraft (fighter type) by each of two subjects for both fixed-base and motion-base conditions. Acceptable time delay is defined as the largest amount of delay that can be inserted simultaneously into the visual and motion cues before performance degradation occurs. A statistical analysis of the data was made to establish this value of time delay. Audio side task provided quantitative data that documented the subject's work level.

A New Generation of Real-Time Systems in the JET Tokamak

NASA Astrophysics Data System (ADS)

Alves, Diogo; Neto, Andre C.; Valcarcel, Daniel F.; Felton, Robert; Lopez, Juan M.; Barbalace, Antonio; Boncagni, Luca; Card, Peter; De Tommasi, Gianmaria; Goodyear, Alex; Jachmich, Stefan; Lomas, Peter J.; Maviglia, Francesco; McCullen, Paul; Murari, Andrea; Rainford, Mark; Reux, Cedric; Rimini, Fernanda; Sartori, Filippo; Stephen, Adam V.; Vega, Jesus; Vitelli, Riccardo; Zabeo, Luca; Zastrow, Klaus-Dieter

2014-04-01

Recently, a new recipe for developing and deploying real-time systems has become increasingly adopted in the JET tokamak. Powered by the advent of x86 multi-core technology and the reliability of JET's well established Real-Time Data Network (RTDN) to handle all real-time I/O, an official Linux vanilla kernel has been demonstrated to be able to provide real-time performance to user-space applications that are required to meet stringent timing constraints. In particular, a careful rearrangement of the Interrupt ReQuests' (IRQs) affinities together with the kernel's CPU isolation mechanism allows one to obtain either soft or hard real-time behavior depending on the synchronization mechanism adopted. Finally, the Multithreaded Application Real-Time executor (MARTe) framework is used for building applications particularly optimised for exploring multi-core architectures. In the past year, four new systems based on this philosophy have been installed and are now part of JET's routine operation. The focus of the present work is on the configuration aspects that enable these new systems' real-time capability. Details are given about the common real-time configuration of these systems, followed by a brief description of each system together with results regarding their real-time performance. A cycle time jitter analysis of a user-space MARTe based application synchronizing over a network is also presented. The goal is to compare its deterministic performance while running on a vanilla and on a Messaging Real time Grid (MRG) Linux kernel.

The Impact of Part Time Employment on Students' Health and Academic Performance: A Scottish Perspective

ERIC Educational Resources Information Center

Carney, Claire; McNeish, Sharon; McColl, John

2005-01-01

The purpose of this study was to examine the relationship between part time working, mental and physical health and academic performance. Fifty per cent of the undergraduate full time respondents had part time jobs. Mean pay per hour was ?4.25 and mean number of hours worked was 14 hours. When the current state of students' health was compared to…

Cognitive load and task condition in event- and time-based prospective memory: an experimental investigation.

PubMed

Khan, Azizuddin; Sharma, Narendra K; Dixit, Shikha

2008-09-01

Prospective memory is memory for the realization of delayed intention. Researchers distinguish 2 kinds of prospective memory: event- and time-based (G. O. Einstein & M. A. McDaniel, 1990). Taking that distinction into account, the present authors explored participants' comparative performance under event- and time-based tasks. In an experimental study of 80 participants, the authors investigated the roles of cognitive load and task condition in prospective memory. Cognitive load (low vs. high) and task condition (event- vs. time-based task) were the independent variables. Accuracy in prospective memory was the dependent variable. Results showed significant differential effects under event- and time-based tasks. However, the effect of cognitive load was more detrimental in time-based prospective memory. Results also revealed that time monitoring is critical in successful performance of time estimation and so in time-based prospective memory. Similarly, participants' better performance on the event-based prospective memory task showed that they acted on the basis of environment cues. Event-based prospective memory was environmentally cued; time-based prospective memory required self-initiation.

Accelerating moderately stiff chemical kinetics in reactive-flow simulations using GPUs

NASA Astrophysics Data System (ADS)

Niemeyer, Kyle E.; Sung, Chih-Jen

2014-01-01

The chemical kinetics ODEs arising from operator-split reactive-flow simulations were solved on GPUs using explicit integration algorithms. Nonstiff chemical kinetics of a hydrogen oxidation mechanism (9 species and 38 irreversible reactions) were computed using the explicit fifth-order Runge-Kutta-Cash-Karp method, and the GPU-accelerated version performed faster than single- and six-core CPU versions by factors of 126 and 25, respectively, for 524,288 ODEs. Moderately stiff kinetics, represented with mechanisms for hydrogen/carbon-monoxide (13 species and 54 irreversible reactions) and methane (53 species and 634 irreversible reactions) oxidation, were computed using the stabilized explicit second-order Runge-Kutta-Chebyshev (RKC) algorithm. The GPU-based RKC implementation demonstrated an increase in performance of nearly 59 and 10 times, for problem sizes consisting of 262,144 ODEs and larger, than the single- and six-core CPU-based RKC algorithms using the hydrogen/carbon-monoxide mechanism. With the methane mechanism, RKC-GPU performed more than 65 and 11 times faster, for problem sizes consisting of 131,072 ODEs and larger, than the single- and six-core RKC-CPU versions, and up to 57 times faster than the six-core CPU-based implicit VODE algorithm on 65,536 ODEs. In the presence of more severe stiffness, such as ethylene oxidation (111 species and 1566 irreversible reactions), RKC-GPU performed more than 17 times faster than RKC-CPU on six cores for 32,768 ODEs and larger, and at best 4.5 times faster than VODE on six CPU cores for 65,536 ODEs. With a larger time step size, RKC-GPU performed at best 2.5 times slower than six-core VODE for 8192 ODEs and larger. Therefore, the need for developing new strategies for integrating stiff chemistry on GPUs was discussed.

The effect of pacing strategy on physiological, kinetic and performance variables during simulated rowing ergometer.

PubMed

Dimakopoulou, Eleni; Zacharogiannis, Elias; Chairopoulou, Chrysoula; Kaloupsis, Socratis; Platanou, Theodoros

2017-02-21

This study compared the effects of self selected (SSP), negative (NPS) and even (EPS) pacing strategy on performance time, kinetic and physiological variables in overall 2km rowing and in first and second 1km. Fifteen male rowers (15.37 ± 1.34 yrs) realized four tests: an incremental test on a rowing ergometer to determine their VO2peak and three experimental 2 km rowing race, where first 1km was manipulated. From SSP a negative pacing strategy, 4% slower than the mean velocity of SSP, and an even pacing strategy (EPS) with mean velocity of SSP, were developed. High stroke rate and better performance time was observed in SSP. Fstr and Fpeak decreased, whereas performance time increased, in SSP and EPS from first to second 1km.Unlike, performance time, stroke rate and Pst in NPS presented better values (p=0.001) with the exception of decreased stroke length (p=0.03). There was an increase in physiological responses in all pacing strategies from first to second 1km (p=0.001). Performance time, stroke rate and Fstr were better in SSP and EPS compared to NPS in first 1km (p=0.001). VE, VE/VO2, VCO2 were better in SSP and EPS compared to NPS (p=0.001) in both first and second 1km. Stroke length was smaller in SSP compared to NPS and EPS in second 1km (p=0.001). Self selected pacing (parabolic-shaped profile) allowed rowers to cover the 2 km distance in higher stroke rate and in shorter performance time compared to negative and even pacing strategies presenting same physiological responses.

Longitudinal development of prefrontal function during early childhood.

PubMed

Moriguchi, Yusuke; Hiraki, Kazuo

2011-04-01

This is a longitudinal study on development of prefrontal function in young children. Prefrontal areas have been observed to develop dramatically during early childhood. To elucidate this development, we gave children cognitive shifting tasks related to prefrontal function at 3 years of age (Time 1) and 4 years of age (Time 2). We then monitored developmental changes in behavioral performance and examined prefrontal activation using near infrared spectroscopy. We found that children showed better behavioral performance and significantly stronger inferior prefrontal activation at Time 2 than they did at Time 1. Moreover, we demonstrated individual differences in prefrontal activation for the same behavioral tasks. Children who performed better in tasks at Time 1 showed significant activation of the right inferior prefrontal regions at Time 1 and significant activation of the bilateral inferior prefrontal regions at Time 2. Children who showed poorer performance at Time 1 exhibited no significant inferior prefrontal activation at Time 1 but significant left inferior prefrontal activation at Time 2. These results indicate the importance of the longitudinal method to address the link between cognitive and neural development. Copyright © 2011 Elsevier Ltd. All rights reserved.

PrismTech Data Distribution Service Java API Evaluation

NASA Technical Reports Server (NTRS)

Riggs, Cortney

2008-01-01

My internship duties with Launch Control Systems required me to start performance testing of an Object Management Group's (OMG) Data Distribution Service (DDS) specification implementation by PrismTech Limited through the Java programming language application programming interface (API). DDS is a networking middleware for Real-Time Data Distribution. The performance testing involves latency, redundant publishers, extended duration, redundant failover, and read performance. Time constraints allowed only for a data throughput test. I have designed the testing applications to perform all performance tests when time is allowed. Performance evaluation data such as megabits per second and central processing unit (CPU) time consumption were not easily attainable through the Java programming language; they required new methods and classes created in the test applications. Evaluation of this product showed the rate that data can be sent across the network. Performance rates are better on Linux platforms than AIX and Sun platforms. Compared to previous C++ programming language API, the performance evaluation also shows the language differences for the implementation. The Java API of the DDS has a lower throughput performance than the C++ API.

26 CFR 301.7503-1 - Time for performance of acts where last day falls on Saturday, Sunday, or legal holiday.

Code of Federal Regulations, 2012 CFR

2012-04-01

... falls on Saturday, Sunday, or legal holiday. 301.7503-1 Section 301.7503-1 Internal Revenue INTERNAL... where last day falls on Saturday, Sunday, or legal holiday. (a) In general. Section 7503 provides that... falls on a Saturday, Sunday, or legal holiday, such act shall be considered performed timely if...

26 CFR 301.7503-1 - Time for performance of acts where last day falls on Saturday, Sunday, or legal holiday.

Code of Federal Regulations, 2011 CFR

2011-04-01

... falls on Saturday, Sunday, or legal holiday. 301.7503-1 Section 301.7503-1 Internal Revenue INTERNAL... where last day falls on Saturday, Sunday, or legal holiday. (a) In general. Section 7503 provides that... falls on a Saturday, Sunday, or legal holiday, such act shall be considered performed timely if...

26 CFR 301.7503-1 - Time for performance of acts where last day falls on Saturday, Sunday, or legal holiday.

Code of Federal Regulations, 2014 CFR

2014-04-01

... falls on Saturday, Sunday, or legal holiday. 301.7503-1 Section 301.7503-1 Internal Revenue INTERNAL... where last day falls on Saturday, Sunday, or legal holiday. (a) In general. Section 7503 provides that... falls on a Saturday, Sunday, or legal holiday, such act shall be considered performed timely if...

26 CFR 301.7503-1 - Time for performance of acts where last day falls on Saturday, Sunday, or legal holiday.

Code of Federal Regulations, 2013 CFR

2013-04-01

... falls on Saturday, Sunday, or legal holiday. 301.7503-1 Section 301.7503-1 Internal Revenue INTERNAL... where last day falls on Saturday, Sunday, or legal holiday. (a) In general. Section 7503 provides that... falls on a Saturday, Sunday, or legal holiday, such act shall be considered performed timely if...

26 CFR 301.7503-1 - Time for performance of acts where last day falls on Saturday, Sunday, or legal holiday.

Code of Federal Regulations, 2010 CFR

2010-04-01

... falls on Saturday, Sunday, or legal holiday. 301.7503-1 Section 301.7503-1 Internal Revenue INTERNAL... where last day falls on Saturday, Sunday, or legal holiday. (a) In general. Section 7503 provides that... falls on a Saturday, Sunday, or legal holiday, such act shall be considered performed timely if...

Delivery versus Time Devoted to Assignments: The Effect on Course Performance

ERIC Educational Resources Information Center

Guidry, Krisandra

2017-01-01

Research in the area of amount of time spent on assignments and effect on course performance has focused exclusively either on the lecture or online format, but not comparison of the two. Nowhere has both modes of delivery been studied using an objective measure of course involvement. This study examines what is most significant in predicting a…

7 CFR 56.28 - Types of service.

Code of Federal Regulations, 2010 CFR

2010-01-01

.... Charges or fees are based on time, travel, and expenses needed to perform the work. [69 FR 76375, Dec. 21... of shell eggs. Requests are made not on a regular basis. Charges or fees are based on the time, travel, and expenses needed to perform the work. This service also may be called the fee grading service...

7 CFR 56.28 - Types of service.

Code of Federal Regulations, 2013 CFR

2013-01-01

.... Charges or fees are based on time, travel, and expenses needed to perform the work. [69 FR 76375, Dec. 21... of shell eggs. Requests are made not on a regular basis. Charges or fees are based on the time, travel, and expenses needed to perform the work. This service also may be called the fee grading service...

7 CFR 56.28 - Types of service.

Code of Federal Regulations, 2014 CFR

2014-01-01

.... Charges or fees are based on time, travel, and expenses needed to perform the work. [69 FR 76375, Dec. 21... of shell eggs. Requests are made not on a regular basis. Charges or fees are based on the time, travel, and expenses needed to perform the work. This service also may be called the fee grading service...

7 CFR 56.28 - Types of service.

Code of Federal Regulations, 2012 CFR

2012-01-01

.... Charges or fees are based on time, travel, and expenses needed to perform the work. [69 FR 76375, Dec. 21... of shell eggs. Requests are made not on a regular basis. Charges or fees are based on the time, travel, and expenses needed to perform the work. This service also may be called the fee grading service...

7 CFR 56.28 - Types of service.

Code of Federal Regulations, 2011 CFR

2011-01-01

.... Charges or fees are based on time, travel, and expenses needed to perform the work. [69 FR 76375, Dec. 21... of shell eggs. Requests are made not on a regular basis. Charges or fees are based on the time, travel, and expenses needed to perform the work. This service also may be called the fee grading service...

Analysis of Time-on-Task, Behavior Experiences, and Performance in Two Online Courses with Different Authentic Learning Tasks

ERIC Educational Resources Information Center

Park, Sanghoon

2017-01-01

This paper reports the findings of a comparative analysis of online learner behavioral interactions, time-on-task, attendance, and performance at different points throughout a semester (beginning, during, and end) based on two online courses: one course offering authentic discussion-based learning activities and the other course offering authentic…

A real-time diagnostic and performance monitor for UNIX. M.S. Thesis

NASA Technical Reports Server (NTRS)

Dong, Hongchao

1992-01-01

There are now over one million UNIX sites and the pace at which new installations are added is steadily increasing. Along with this increase, comes a need to develop simple efficient, effective and adaptable ways of simultaneously collecting real-time diagnostic and performance data. This need exists because distributed systems can give rise to complex failure situations that are often un-identifiable with single-machine diagnostic software. The simultaneous collection of error and performance data is also important for research in failure prediction and error/performance studies. This paper introduces a portable method to concurrently collect real-time diagnostic and performance data on a distributed UNIX system. The combined diagnostic/performance data collection is implemented on a distributed multi-computer system using SUN4's as servers. The approach uses existing UNIX system facilities to gather system dependability information such as error and crash reports. In addition, performance data such as CPU utilization, disk usage, I/O transfer rate and network contention is also collected. In the future, the collected data will be used to identify dependability bottlenecks and to analyze the impact of failures on system performance.

Swimming performance in juvenile shortnose sturgeon (Acipenser brevirostrum): the influence of time interval and velocity increments on critical swimming tests

PubMed Central

Kieffer, James D.

2017-01-01

Abstract The most utilized method to measure swimming performance of fishes has been the critical swimming speed (UCrit) test. In this test, the fish is forced to swim against an incrementally increasing flow of water until fatigue. Before the water velocity is increased, the fish swims at the water velocity for a specific, pre-arranged time interval. The magnitude of the velocity increments and the time interval for each swimming period can vary across studies making the comparison between and within species difficult. This issue has been acknowledged in the literature, however, little empirical evidence exists that tests the importance of velocity and time increments on swimming performance in fish. A practical application for fish performance is through the design of fishways that enable fish to bypass anthropogenic structures (e.g. dams) that block migration routes, which is one of the causes of world-wide decline in sturgeon populations. While fishways will improve sturgeon conservation, they need to be specifically designed to accommodate the swimming capabilities specific for sturgeons, and it is possible that current swimming methodologies have under-estimated the swimming performance of sturgeons. The present study assessed the UCrit of shortnose sturgeon using modified UCrit to determine the importance of velocity increment (5 and 10 cm s−1) and time (5, 15 and 30 min) intervals on swimming performance. UCrit was found to be influenced by both time interval and water velocity. UCrit was generally lower in sturgeon when they were swum using 5cm s−1 compared with 10 cm s−1 increments. Velocity increment influences the UCrit more than time interval. Overall, researchers must consider the impacts of using particular swimming criteria when designing their experiments. PMID:28835841

Impact of a workplace 'sit less, move more' program on efficiency-related outcomes of office employees.

PubMed

Puig-Ribera, Anna; Bort-Roig, Judit; Giné-Garriga, Maria; González-Suárez, Angel M; Martínez-Lemos, Iván; Fortuño, Jesús; Martori, Joan C; Muñoz-Ortiz, Laura; Milà, Raimon; Gilson, Nicholas D; McKenna, Jim

2017-05-16

Few studies have examined the impact of 'sit less, move more' interventions on workplace performance. This study assessed the short and mid-term impacts of and patterns of change within, a 19-week workplace web-based intervention (Walk@WorkSpain; W@WS; 2010-11) on employees´ presenteeism, mental well-being and lost work performance. A site randomised control trial recruited employees at six Spanish university campuses (n = 264; 42 ± 10 years; 171 female), assigned by worksite and campus to an Intervention (IG; used W@WS; n = 129; 87 female) or an active Comparison group (A-CG; pedometer, paper diary and self-reported sitting time; n = 135; 84 female). A linear mixed model assessed changes between the baseline, ramping (8 weeks), maintenance (11 weeks) and follow-up (two months) phases for the IG versus A-CG on (i) % of lost work productivity (Work Limitations Questionnaire; WLQ); (ii) three scales for presenteeism (WLQ) assessing difficulty meeting scheduling demands (Time), performing cognitive and inter-personal tasks (Mental-Interpersonal) and decrements in meeting the quantity, quality and timeliness of completed work (Output); and (iii) mental well-being (Warwick-Edinburgh Mental Well-being Scale). T-tests assessed differences between groups for changes on the main outcomes. In the IG, a multivariate logistic regression model identified patterns of response according to baseline socio-demographic variables, physical activity and sitting time. There was a significant 2 (group) × 2 (program time points) interaction for the Time (F [3]=8.69, p = 0.005), Mental-Interpersonal (F [3]=10.01, p = 0.0185), Output scales for presenteeism (F [3]=8.56, p = 0.0357), and for % of lost work performance (F [3]=10.31, p = 0.0161). Presenteeism and lost performance rose significantly in both groups across all study time points; after baseline performance was consistently better in the IG than in the A-CG. Better performance was linked to employees being more active (Time, p = 0.041) and younger (Mental-interpersonal, p = 0.057; Output, p = 0.017). Higher total sitting time during nonworking days (Mental-interpersonal, p = 0.019) and lower sitting time during workdays (WLQ Index, p = 0.013) also improved performance. Versus an active comparison condition, a 'sit less, move more` workplace intervention effectively reduced an array of markers of lost workday productivity. NCT02960750 ; Date of registration: 07/11/2016.

The Effects of Creatine Supplementation on Explosive Performance and Optimal Individual Postactivation Potentiation Time.

PubMed

Wang, Chia-Chi; Yang, Ming-Ta; Lu, Kang-Hao; Chan, Kuei-Hui

2016-03-04

Creatine plays an important role in muscle energy metabolism. Postactivation potentiation (PAP) is a phenomenon that can acutely increase muscle power, but it is an individualized process that is influenced by muscle fatigue. This study examined the effects of creatine supplementation on explosive performance and the optimal individual PAP time during a set of complex training bouts. Thirty explosive athletes performed tests of back squat for one repetition maximum (1RM) strength and complex training bouts for determining the individual optimal timing of PAP, height and peak power of a counter movement jump before and after the supplementation. Subjects were assigned to a creatine or placebo group and then consumed 20 g of creatine or carboxymethyl cellulose per day for six days. After the supplementation, the 1RM strength in the creatine group significantly increased (p < 0.05). The optimal individual PAP time in the creatine group was also significant earlier than the pre-supplementation and post-supplementation of the placebo group (p < 0.05). There was no significant difference in jump performance between the groups. This study demonstrates that creatine supplementation improves maximal muscle strength and the optimal individual PAP time of complex training but has no effect on explosive performance.

The Effects of Creatine Supplementation on Explosive Performance and Optimal Individual Postactivation Potentiation Time

PubMed Central

Wang, Chia-Chi; Yang, Ming-Ta; Lu, Kang-Hao; Chan, Kuei-Hui

2016-01-01

Creatine plays an important role in muscle energy metabolism. Postactivation potentiation (PAP) is a phenomenon that can acutely increase muscle power, but it is an individualized process that is influenced by muscle fatigue. This study examined the effects of creatine supplementation on explosive performance and the optimal individual PAP time during a set of complex training bouts. Thirty explosive athletes performed tests of back squat for one repetition maximum (1RM) strength and complex training bouts for determining the individual optimal timing of PAP, height and peak power of a counter movement jump before and after the supplementation. Subjects were assigned to a creatine or placebo group and then consumed 20 g of creatine or carboxymethyl cellulose per day for six days. After the supplementation, the 1RM strength in the creatine group significantly increased (p < 0.05). The optimal individual PAP time in the creatine group was also significant earlier than the pre-supplementation and post-supplementation of the placebo group (p < 0.05). There was no significant difference in jump performance between the groups. This study demonstrates that creatine supplementation improves maximal muscle strength and the optimal individual PAP time of complex training but has no effect on explosive performance. PMID:26959056

Effects of repeated snowboard exercise in virtual reality with time lags of visual scene behind body rotation on head stability and subjective slalom run performance in healthy young subjects.

PubMed

Wada, Yoshiro; Nishiike, Suetaka; Kitahara, Tadashi; Yamanaka, Toshiaki; Imai, Takao; Ito, Taeko; Sato, Go; Matsuda, Kazunori; Kitamura, Yoshiaki; Takeda, Noriaki

2016-11-01

After repeated snowboard exercises in the virtual reality (VR) world with increasing time lags in trials 3-8, it is suggested that the adaptation to repeated visual-vestibulosomatosensory conflict in the VR world improved dynamic posture control and motor performance in the real world without the development of motion sickness. The VR technology was used and the effects of repeated snowboard exercise examined in the VR world with time lags between visual scene and body rotation on the head stability and slalom run performance during exercise in healthy subjects. Forty-two healthy young subjects participated in the study. After trials 1 and 2 of snowboard exercise in the VR world without time lag, trials 3-8 were conducted with 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6 s time lags of the visual scene that the computer creates behind board rotation, respectively. Finally, trial 9 was conducted without time lag. Head linear accelerations and subjective slalom run performance were evaluated. The standard deviations of head linear accelerations in inter-aural direction were significantly increased in trial 8, with a time lag of 0.6 s, but significantly decreased in trial 9 without a time lag, compared with those in trial 2 without a time lag. The subjective scores of slalom run performance were significantly decreased in trial 8, with a time lag of 0.6 s, but significantly increased in trial 9 without a time lag, compared with those in trial 2 without a time lag. Motion sickness was not induced in any subjects.

Effect of type of cue, type of response, time delay and two different ongoing tasks on prospective memory functioning after acquired brain injury.

PubMed

Raskin, Sarah A; Buckheit, Carol A; Waxman, Amanda

2012-01-01

Failures of prospective memory (PM) are one of the most frequent, and least studied, sequelae of brain injury. PM, also referred to as memory for intentions, is the ability to remember to carry out a future task. Successful completion of a PM task requires the ability to monitor time, keep the action to be performed periodically in awareness, remember the task to be performed, and initiate the action. Although PM has been shown to be a common difficulty after brain injury, it remains unknown which aspects of performance are impaired. In this study, the performance of 25 individuals with brain injury and that of 25 healthy participants were measured separately on the following variables: time until completion of the task, difficulty of the ongoing task being performed while waiting, whether the task to be performed is an action or is verbal, and whether the cue to perform the task is the passing of a particular amount of time (e.g., 10 minutes) or is an external cue (e.g., an alarm sounding). Individuals with brain injury demonstrated impairment compared to healthy adults on virtually all variables. PM performance was also compared to a battery of standard neuropsychological measures of attention, memory, and executive functions, and to self-report measures of PM functioning, in order to determine the underlying cognitive deficits responsible for poor PM performance, if any. PM performance was correlated with measures of executive functioning but not to self-report measures of PM functioning. Implications are discussed in terms of cognitive rehabilitation recommendations.

SiPM photosensors and fast timing readout for the Barrel Time-of-Flight detector in bar PANDA

NASA Astrophysics Data System (ADS)

Suzuki, K.

2018-03-01

The Barrel Time-of-Flight detector system will be installed in the upcoming bar PANDA experiment at FAIR in Germany. The detector has a barrel shape of phi=0.5 m and 1.8 m long, covering about 5 m2, which corresponds to the laboratory polar angle coverage of 22o<θ<140o. The detector is a scintillation tile hodoscope. A single scintillation tile segment has a dimension of 90× 30 mm2 and 5 mm thickness, and photons are detected by Silicon Photomultipliers at both ends. 4 Silicon Photomultipliers are combined to work as a single sensor in order to increase the sensitive area and to improve the timing performance. In total, the system consists of 1920 scintillator tiles, 3840 readout channels, and makes use of 15360 Silicon Photomultiplier sensors. In this paper, the requirement, design and the result of an actual performance test of the bar PANDA Barrel Time-of-Flight detector are presented. The test shows that the current design fulfils satisfactorily the required timing performance (σt~ 56 ps) and the timing performance depends little on the hit position on the surface.

Time compression diseconomies in environmental management: the effect of assimilation on environmental performance.

PubMed

Lannelongue, Gustavo; Gonzalez-Benito, Javier; Gonzalez-Benito, Oscar; Gonzalez-Zapatero, Carmen

2015-01-01

This research addresses the relationship between an organisation's assimilation of its environmental management system (EMS), the experience it gains through it, and its environmental performance. Assimilation here refers to the degree to which the requirements of the management standard are integrated within a plant's daily operations. Basing ourselves on the heterogeneity of organisations, we argue that assimilation and experience will inform environmental performance. Furthermore, we posit that the relationship between assimilation and environmental performance depends on experience. The attempt to obtain greater assimilation in a shorter time leads an organisation to record a poorer environmental outcome, which we shall refer to as time compression diseconomies in environmental management. We provide empirical evidence based on 154 plants pertaining to firms in Spain subject to the European Union's CO2 Emissions Trading System. Copyright © 2014 Elsevier Ltd. All rights reserved.

Reliability, validity and description of timed performance of the Jebsen-Taylor Test in patients with muscular dystrophies.

PubMed

Artilheiro, Mariana Cunha; Fávero, Francis Meire; Caromano, Fátima Aparecida; Oliveira, Acary de Souza Bulle; Carvas, Nelson; Voos, Mariana Callil; Sá, Cristina Dos Santos Cardoso de

2017-12-08

The Jebsen-Taylor Test evaluates upper limb function by measuring timed performance on everyday activities. The test is used to assess and monitor the progression of patients with Parkinson disease, cerebral palsy, stroke and brain injury. To analyze the reliability, internal consistency and validity of the Jebsen-Taylor Test in people with Muscular Dystrophy and to describe and classify upper limb timed performance of people with Muscular Dystrophy. Fifty patients with Muscular Dystrophy were assessed. Non-dominant and dominant upper limb performances on the Jebsen-Taylor Test were filmed. Two raters evaluated timed performance for inter-rater reliability analysis. Test-retest reliability was investigated by using intraclass correlation coefficients. Internal consistency was assessed using the Cronbach alpha. Construct validity was conducted by comparing the Jebsen-Taylor Test with the Performance of Upper Limb. The internal consistency of Jebsen-Taylor Test was good (Cronbach's α=0.98). A very high inter-rater reliability (0.903-0.999), except for writing with an Intraclass correlation coefficient of 0.772-1.000. Strong correlations between the Jebsen-Taylor Test and the Performance of Upper Limb Module were found (rho=-0.712). The Jebsen-Taylor Test is a reliable and valid measure of timed performance for people with Muscular Dystrophy. Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

Why are You Late?: Investigating the Role of Time Management in Time-Based Prospective Memory

PubMed Central

Waldum, Emily R; McDaniel, Mark A.

2016-01-01

Time-based prospective memory tasks (TBPM) are those that are to be performed at a specific future time. Contrary to typical laboratory TBPM tasks (e.g., “hit the “z” key every 5 minutes”), many real-world TBPM tasks require more complex time-management processes. For instance to attend an appointment on time, one must estimate the duration of the drive to the appointment and then utilize this estimate to create and execute a secondary TBPM intention (e.g., “I need to start driving by 1:30 to make my 2:00 appointment on time”). Future under- and overestimates of drive time can lead to inefficient TBPM performance with the former lending to missed appointments and the latter to long stints in the waiting room. Despite the common occurrence of complex TBPM tasks in everyday life, to date, no studies have investigated how components of time management, including time estimation, affect behavior in such complex TBPM tasks. Therefore, the current study aimed to investigate timing biases in both older and younger adults and further to determine how such biases along with additional time management components including planning and plan fidelity influence complex TBPM performance. Results suggest for the first time that younger and older adults do not always utilize similar timing strategies, and as a result, can produce differential timing biases under the exact same environmental conditions. These timing biases, in turn, play a vital role in how efficiently both younger and older adults perform a later TBPM task that requires them to utilize their earlier time estimate. PMID:27336325

Associations between motor timing, music practice, and intelligence studied in a large sample of twins.

PubMed

Ullén, Fredrik; Mosing, Miriam A; Madison, Guy

2015-03-01

Music performance depends critically on precise processing of time. A common model behavior in studies of motor timing is isochronous serial interval production (ISIP), that is, hand/finger movements with a regular beat. ISIP accuracy is related to both music practice and intelligence. Here we present a study of these associations in a large twin cohort, demonstrating that the effects of music practice and intelligence on motor timing are additive, with no significant multiplicative (interaction) effect. Furthermore, the association between music practice and motor timing was analyzed with the use of a co-twin control design using intrapair differences. These analyses revealed that the phenotypic association disappeared when all genetic and common environmental factors were controlled. This suggests that the observed association may not reflect a causal effect of music practice on ISIP performance but rather reflect common influences (e.g., genetic effects) on both outcomes. The relevance of these findings for models of practice and expert performance is discussed. © 2014 New York Academy of Sciences.

Postactivation Potentation Effects From Accommodating Resistance Combined With Heavy Back Squats on Short Sprint Performance.

PubMed

Wyland, Timothy P; Van Dorin, Joshua D; Reyes, G Francis Cisco

2015-11-01

Applying accommodating resistance combined with isoinertial resistance has been demonstrated to be effective in improving neuromuscular attributes important for sport performance. The main purpose of this study was to determine whether short sprints can be acutely enhanced after several sets of back squats with or without accommodating resistance. Twenty recreationally resistance-trained males (age: 23.3 ± 4.4 years; height: 178.9 ± 6.5 cm; weight: 88.3 ± 10.8 kg) performed pre-post testing on 9.1-m sprint time. Three different interventions were implemented in randomized order between pre-post 9.1-m sprints. On 3 separate days, subjects either sat for 5 minutes (CTRL), performed 5 sets of 3 repetitions at 85% of their 1 repetition maximum (1RM) with isoinertial load (STND), or performed 5 sets of 3 repetitions at 85% of their 1RM, with 30% of the total resistance coming from elastic band tension (BAND) between pre-post 9.1-m sprint testing. Posttesting for 9.1-m sprint time occurred immediately after the last set of squats (Post-Immediate) and on every minute for 4 minutes after the last set of squats (Post-1min, Post-2min, Post-3min, and Post-4min). Repeated-measures analysis of variance statistical analyses revealed no significant changes in sprint time across posttesting times during the CTRL and STND condition. During the BAND condition, sprint time significantly decreased from Post-Immediate to Post-4min (p = 0.002). The uniqueness of accommodating resistance could create an optimal postactivation potentiation effect to increase neuromuscular performance. Coaches and athletes can implement heavy accommodating resistance exercises to their warm-up when improving acute sprint time is desired.

A single robotic session that guides or increases movement error in survivors post-chronic stroke: which intervention is best to boost the learning of a timing task?

PubMed

Bouchard, Amy E; Corriveau, Hélène; Milot, Marie-Hélène

2017-08-01

Timing deficits can have a negative impact on the lives of survivors post-chronic stroke. Studies evaluating ways to improve timing post stroke are scarce. The goal of the study was to evaluate the impact of a single session of haptic guidance (HG) and error amplification (EA) robotic training interventions on the improvement of post-stroke timing accuracy. Thirty-four survivors post-chronic stroke were randomly assigned to HG or EA. Participants played a computerized pinball-like game with their affected hand positioned in a robot that either helped them perform better (HG) or worse (EA) during the task. A baseline and retention phase preceded and followed HG and EA, respectively, in order to assess their efficiency at improving absolute timing errors. The impact of the side of the stroke lesion on the participants' performance during the timing task was also explored for each training group. An improvement in timing performance was only noted following HG (8.9 ± 4.9 ms versus 7.8 ± 5.3 ms, p = 0.032). Moreover, for the EA group only, participants with a left-sided stroke lesion showed a worsening in performance as compared to those with a right-sided stroke lesion (p = 0.001). Helping survivors post-chronic stroke perform a timing-based task is beneficial to learning. Future studies should explore longer and more frequent HG training sessions in order to further promote post stroke motor recovery. Implications for Rehabilitation Timing is crucial for the accomplishment of daily tasks. The number of studies dedicated to improving timing is scarce in the literature, even though timing deficits are common post stroke. This innovative study evaluated the impact of a single session of haptic guidance-HG and error amplification-EA robotic training interventions on improvements in timing accuracy among survivors post chronic stroke. HG robotic training improves timing accuracy more than EA among survivors post chronic stroke.

The Effects of Preexercise Caffeinated Coffee Ingestion on Endurance Performance: An Evidence-Based Review.

PubMed

Higgins, Simon; Straight, Chad R; Lewis, Richard D

2016-06-01

Endurance athletes commonly ingest caffeine as a means to enhance training intensity and competitive performance. A widely-used source of caffeine is coffee, however conflicting evidence exists regarding the efficacy of coffee in improving endurance performance. In this context, the aims of this evidence-based review were threefold: 1) to evaluate the effects of preexercise coffee on endurance performance, 2) to evaluate the effects of coffee on perceived exertion during endurance performance, and 3) to translate the research into usable information for athletes to make an informed decision regarding the intake of caffeine via coffee as a potential ergogenic aid. Searches of three major databases were performed using terms caffeine and coffee, or coffee-caffeine, and endurance, or aerobic. Included studies (n = 9) evaluated the effects of caffeinated coffee on human subjects, provided the caffeine dose administered, administered caffeine ≥ 45 min before testing, and included a measure of endurance performance (e.g., time trial). Significant improvements in endurance performance were observed in five of nine studies, which were on average 24.2% over controls for time to exhaustion trials, and 3.1% for time to completion trials. Three of six studies found that coffee reduced perceived exertion during performance measures significantly more than control conditions (p < .05). Based on the reviewed studies there is moderate evidence supporting the use of coffee as an ergogenic aid to improve performance in endurance cycling and running. Coffee providing 3-8.1 mg/kg (1.36-3.68 mg/lb) of caffeine may be used as a safe alternative to anhydrous caffeine to improve endurance performance.

NAS-Wide Fast-Time Simulation Study for Evaluating Performance of UAS Detect-and-Avoid Alerting and Guidance Systems

NASA Technical Reports Server (NTRS)

Lee, Seung Man; Park, Chunki; Cone, Andrew Clayton; Thipphavong, David P.; Santiago, Confesor

2016-01-01

This presentation contains the analysis results of NAS-wide fast-time simulations with UAS and VFR traffic for a single day for evaluating the performance of Detect-and-Avoid (DAA) alerting and guidance systems. This purpose of this study was to help refine and validate MOPS alerting and guidance requirements. In this study, we generated plots of all performance metrics that are specified by RTCA SC-228 Minimum Operational Performance Standards (MOPS): 1) to evaluate the sensitivity of alerting parameters on the performance metrics of each DAA alert type: Preventive, Corrective, and Warning alerts and 2) to evaluate the effect of sensor uncertainty on DAA alerting and guidance performance.

"I Think Everyone's Been Thrilled": Music Teachers' Perspectives on School Music Performance Collaborations

ERIC Educational Resources Information Center

Sutherland, Andrew Thomas

2017-01-01

Thanks to the efforts of music teachers in arranging concerts, young musicians develop a multitude of skills when performing with others. Music teachers are notoriously time-poor with the pressures of various curricular and co-curricular demands. To find time to provide performance opportunities for students that involve other schools adds layers…

General Slowing and Education Mediate Task Switching Performance Across the Life-Span

PubMed Central

Moretti, Luca; Semenza, Carlo; Vallesi, Antonino

2018-01-01

Objective: This study considered the potential role of both protective factors (cognitive reserve, CR) and adverse ones (general slowing) in modulating cognitive flexibility in the adult life-span. Method: Ninety-eight individuals performed a task-switching (TS) paradigm in which we adopted a manipulation concerning the timing between the cue and the target. Working memory demands were minimized by using transparent cues. Additionally, indices of cognitive integrity, depression, processing speed and different CR dimensions were collected and used in linear models accounting for TS performance under the different time constraints. Results: The main results showed similar mixing costs and higher switching costs in older adults, with an overall age-dependent effect of general slowing on these costs. The link between processing speed and TS performance was attenuated when participants had more time to prepare. Among the different CR indices, formal education only was associated with reduced switch costs under time pressure. Discussion: Even though CR is often operationalized as a unitary construct, the present research confirms the benefits of using tools designed to distinguish between different CR dimensions. Furthermore, our results provide empirical support to the assumption that processing speed influence on executive performance depends on time constraints. Finally, it is suggested that whether age differences appear in terms of switch or mixing costs depends on working memory demands (which were low in our tasks with transparent cues). PMID:29780341

Impact of scatterometer wind (ASCAT-A/B) data assimilation on semi real-time forecast system at KIAPS

NASA Astrophysics Data System (ADS)

Han, H. J.; Kang, J. H.

2016-12-01

Since Jul. 2015, KIAPS (Korea Institute of Atmospheric Prediction Systems) has been performing the semi real-time forecast system to assess the performance of their forecast system as a NWP model. KPOP (KIAPS Protocol for Observation Processing) is a part of KIAPS data assimilation system and has been performing well in KIAPS semi real-time forecast system. In this study, due to the fact that KPOP would be able to treat the scatterometer wind data, we analyze the effect of scatterometer wind (ASCAT-A/B) on KIAPS semi real-time forecast system. O-B global distribution and statistics of scatterometer wind give use two information which are the difference between background field and observation is not too large and KPOP processed the scatterometer wind data well. The changes of analysis increment because of O-B global distribution appear remarkably at the bottom of atmospheric field. It also shows that scatterometer wind data cover wide ocean where data would be able to short. Performance of scatterometer wind data can be checked through the vertical error reduction against IFS between background and analysis field and vertical statistics of O-A. By these analysis result, we can notice that scatterometer wind data will influence the positive effect on lower level performance of semi real-time forecast system at KIAPS. After, long-term result based on effect of scatterometer wind data will be analyzed.

System performance testing of the DSN radio science system, Mark 3-78

NASA Technical Reports Server (NTRS)

Berman, A. L.; Mehta, J. S.

1978-01-01

System performance tests are required to evaluate system performance following initial system implementation and subsequent modification, and to validate system performance prior to actual operational usage. Non-real-time end-to-end Radio Science system performance tests are described that are based on the comparison of open-loop radio science data to equivalent closed-loop radio metric data, as well as an abbreviated Radio Science real-time system performance test that validates critical Radio Science System elements at the Deep Space Station prior to actual operational usage.

A Novel Connectionist Network for Solving Long Time-Lag Prediction Tasks

NASA Astrophysics Data System (ADS)

Johnson, Keith; MacNish, Cara

Traditional Recurrent Neural Networks (RNNs) perform poorly on learning tasks involving long time-lag dependencies. More recent approaches such as LSTM and its variants significantly improve on RNNs ability to learn this type of problem. We present an alternative approach to encoding temporal dependencies that associates temporal features with nodes rather than state values, where the nodes explicitly encode dependencies over variable time delays. We show promising results comparing the network's performance to LSTM variants on an extended Reber grammar task.

Multi-domain computerized cognitive training program improves performance of bookkeeping tasks: a matched-sampling active-controlled trial

PubMed Central

Lampit, Amit; Ebster, Claus; Valenzuela, Michael

2014-01-01

Cognitive skills are important predictors of job performance, but the extent to which computerized cognitive training (CCT) can improve job performance in healthy adults is unclear. We report, for the first time, that a CCT program aimed at attention, memory, reasoning and visuo-spatial abilities can enhance productivity in healthy younger adults on bookkeeping tasks with high relevance to real-world job performance. 44 business students (77.3% female, mean age 21.4 ± 2.6 years) were assigned to either (a) 20 h of CCT, or (b) 20 h of computerized arithmetic training (active control) by a matched sampling procedure. Both interventions were conducted over a period of 6 weeks, 3–4 1-h sessions per week. Transfer of skills to performance on a 60-min paper-based bookkeeping task was measured at three time points—baseline, after 10 h and after 20 h of training. Repeated measures ANOVA found a significant Group X Time effect on productivity (F = 7.033, df = 1.745; 73.273, p = 0.003) with a significant interaction at both the 10-h (Relative Cohen's effect size = 0.38, p = 0.014) and 20-h time points (Relative Cohen's effect size = 0.40, p = 0.003). No significant effects were found on accuracy or on Conners' Continuous Performance Test, a measure of sustained attention. The results are discussed in reference to previous findings on the relationship between brain plasticity and job performance. Generalization of results requires further study. PMID:25120510

Independent Analysis of Real-Time, Measured Performance Data From Microcogenerative Fuel Cell Systems Installed in Buildings

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

Dillon, Heather E.; Colella, Whitney G.

2015-06-01

Pacific Northwest National Laboratory (PNNL) is working with industry to independently monitor up to 15 distinct 5 kW-electric (kWe) combined heat and power (CHP) high temperature (HT) proton exchange membrane (PEM) fuel cell systems (FCSs) installed in light commercial buildings. This research paper discusses an evaluation of the first six months of measured performance data acquired at a 1 s sampling rate from real-time monitoring equipment attached to the FCSs at building sites. Engineering performance parameters are independently evaluated. Based on an analysis of the first few months of measured operating data, FCS performance is consistent with manufacturer-stated performance. Initialmore » data indicate that the FCSs have relatively stable performance and a long-term average production of about 4.57 kWe of power. This value is consistent with, but slightly below, the manufacturer's stated rated electric power output of 5 kWe. The measured system net electric efficiency has averaged 33.7%, based on the higher heating value (HHV) of natural gas fuel. This value, also, is consistent with, but slightly below, the manufacturer's stated rated electric efficiency of 36%. The FCSs provide low-grade hot water to the building at a measured average temperature of about 48.4 degrees C, lower than the manufacturer's stated maximum hot water delivery temperature of 65 degrees C. The uptime of the systems is also evaluated. System availability can be defined as the quotient of total operating time compared to time since commissioning. The average values for system availability vary between 96.1 and 97.3%, depending on the FCS evaluated in the field. Performance at rated value for electrical efficiency (PRVeff) can be defined as the quotient of the system time operating at or above the rated electric efficiency and the time since commissioning. The PRVeff varies between 5.6% and 31.6%, depending on the FCS field unit evaluated. Performance at rated value for electrical power (PRVp) can be defined as the quotient of the system time operating at or above the rated electric power and the time since commissioning. PRVp varies between 6.5% and 16.2%. Performance at rated value for electrical efficiency and power (PRVt) can be defined as the quotient of the system time operating at or above both the rated electric efficiency and the electric power output compared to the time since commissioning. PRVt varies between 0.2% and 1.4%. Optimization to determine the manufacturer rating required to achieve PRVt greater than 80% has been performed based on the collected data. For example, for FCS Unit 130 to achieve a PRVt of 95%, it would have to be down-rated to an electrical power output of 3.2 kWe and an electrical efficiency of 29%. The use of PRV as an assessment metric for FCSs has been developed and reported for the first time in this paper. For FCS Unit 130, a maximum decline in electric power output of approximately 18% was observed over a 500 h period in Jan. 2012.« less

Improving cognition by adherence to physical or mental exercise: a moderated mediation analysis.

PubMed

Evers, Andrea; Klusmann, Verena; Schwarzer, Ralf; Heuser, Isabella

2011-05-01

The role of adherence to an intervention is examined to further understand the relationship between performing new challenging activities (either mental or physical ones) and their putative cognitive benefits. Healthy older women (N = 229, age range: 70-93 years) took part in a six-month randomised controlled trial, covering either a physical or mental activity (three × weekly). They completed five tests, measuring episodic and working memory pre- and post-intervention. A moderated mediation model was specified to test the strength of the indirect effect of the activity mode (i.e. physical vs. mental) through adherence (i.e. time spent on course attendance) on levels of baseline cognitive performance. Both physical and mental activity groups performed better over time than the control group (p < 0.001). Adherence predicted cognitive performance (p = 0.011). The indirect effect of the activity mode on cognitive performance through adherence was especially seen when levels of baseline composite scores were low (p = 0.023). Older healthy women can improve episodic and working memory through spending time on a challenging physical or mental activity. Results are most promising for cognitively less fit women. Time spent on course attendance can be interpreted as an adherence indicator that makes a difference for various cognitive outcomes of the intervention.

The effect of extrinsic motivation on cycle time trial performance.

PubMed

Hulleman, Michiel; De Koning, Jos J; Hettinga, Florentina J; Foster, Carl

2007-04-01

Athletes occasionally follow pacing patterns that seem unreasonably aggressive compared with those of prerace performances, potentially because of the motivation provided by competition. This study evaluated the effect of extrinsic motivation on cyclists' time trial performance. Well-trained recreational cyclists (N=7) completed four 1500-m laboratory time trials including a practice trial, two self-paced trials, and a trial where a monetary reward was offered. Time, total power output, power output attributable to aerobic and anaerobic metabolic sources, VO2, and HR were measured. The time required for the second, third, and last (extrinsically motivated) time trials was 133.1 +/- 2.1, 134.1 +/- 3.4, and 133.6 +/- 3.0 s, respectively, and was not different (P>0.05). There were no differences for total (396 +/- 19, 397 +/- 23, and 401 +/- 17 W), aerobic (253 +/- 12, 254 +/- 10, and 246 +/- 13 W), and anaerobic (143 +/- 14, 143 +/- 21, and 155 +/- 11 W) power output. The highest VO2 was not different over consecutive time trials (3.76 +/- 0.19, 3.73 +/- 0.16, and 3.71 +/- 0.22 L x min(-1)). When ranked by performance, without reference to the extrinsic motivation (131.9 +/- 2.4, 133.4 +/- 2.4, and 135.4 +/- 2.5 s), there was a significant difference for the first 100 m and from 100 to 300 m in power output, with a larger total power (560 +/- 102, 491 +/- 82, and 493 +/- 93; and 571 +/- 94, 513 +/- 41, and 484 +/- 88 W) and power attributable to anaerobic sources (446 +/- 100, 384 +/- 80, and 324 +/- 43; and 381 +/- 87, 383 +/- 90, and 289 +/- 91 W) for the fastest trial. Extrinsic motivation did not change the time trial performance, suggesting that 1500-m performance is extremely stable and not readily changeable with simple external motivation. The results suggest that spontaneous improvement in performance for time trials of this duration is attributable to greater early power output, which is primarily attributable to anaerobic metabolic sources.

Multi-AUV autonomous task planning based on the scroll time domain quantum bee colony optimization algorithm in uncertain environment

PubMed Central

Zhang, Rubo; Yang, Yu

2017-01-01

Research on distributed task planning model for multi-autonomous underwater vehicle (MAUV). A scroll time domain quantum artificial bee colony (STDQABC) optimization algorithm is proposed to solve the multi-AUV optimal task planning scheme. In the uncertain marine environment, the rolling time domain control technique is used to realize a numerical optimization in a narrowed time range. Rolling time domain control is one of the better task planning techniques, which can greatly reduce the computational workload and realize the tradeoff between AUV dynamics, environment and cost. Finally, a simulation experiment was performed to evaluate the distributed task planning performance of the scroll time domain quantum bee colony optimization algorithm. The simulation results demonstrate that the STDQABC algorithm converges faster than the QABC and ABC algorithms in terms of both iterations and running time. The STDQABC algorithm can effectively improve MAUV distributed tasking planning performance, complete the task goal and get the approximate optimal solution. PMID:29186166

Multi-AUV autonomous task planning based on the scroll time domain quantum bee colony optimization algorithm in uncertain environment.

PubMed

Li, Jianjun; Zhang, Rubo; Yang, Yu

2017-01-01

Research on distributed task planning model for multi-autonomous underwater vehicle (MAUV). A scroll time domain quantum artificial bee colony (STDQABC) optimization algorithm is proposed to solve the multi-AUV optimal task planning scheme. In the uncertain marine environment, the rolling time domain control technique is used to realize a numerical optimization in a narrowed time range. Rolling time domain control is one of the better task planning techniques, which can greatly reduce the computational workload and realize the tradeoff between AUV dynamics, environment and cost. Finally, a simulation experiment was performed to evaluate the distributed task planning performance of the scroll time domain quantum bee colony optimization algorithm. The simulation results demonstrate that the STDQABC algorithm converges faster than the QABC and ABC algorithms in terms of both iterations and running time. The STDQABC algorithm can effectively improve MAUV distributed tasking planning performance, complete the task goal and get the approximate optimal solution.

Effects of noise on the performance of a memory decision response task

NASA Technical Reports Server (NTRS)

Lawton, B. W.

1972-01-01

An investigation has been made to determine the effects of noise on human performance. Fourteen subjects performed a memory-decision-response task in relative quiet and while listening to tape recorded noises. Analysis of the data obtained indicates that performance was degraded in the presence of noise. Significant increases in problem solution times were found for impulsive noise conditions as compared with times found for the no-noise condition. Performance accuracy was also degraded. Significantly more error responses occurred at higher noise levels; a direct or positive relation was found between error responses and noise level experienced by the subjects.

Responses to Public Comments on EPA’s Standards of Performance for Municipal Solid Waste Landfills and Emission Guidelines and Compliance Times for Municipal Solid Waste Landfills: Proposed Rules - July 2016

EPA Pesticide Factsheets

Responses to Public Comments on EPA’s Standards of Performance for Municipal Solid Waste Landfills and Emission Guidelines and Compliance Times for Municipal Solid Waste Landfills: Proposed Rules - July 2016

Is Implicit Sequence Learning Impaired in Schizophrenia? A Meta-Analysis

ERIC Educational Resources Information Center

Siegert, Richard J.; Weatherall, Mark; Bell, Elliot M.

2008-01-01

Cognition in schizophrenia seems to be characterized by impaired performance on most tests of explicit or declarative learning contrasting with relatively intact performance on most tests of implicit or procedural learning. At the same time there have been conflicting results for studies that have used the Serial Reaction Time (SRT) task to…

Lecture Attendance, Study Time, and Academic Performance: A Panel Data Study

ERIC Educational Resources Information Center

Andrietti, Vincenzo; Velasco, Carlos

2015-01-01

The authors analyze matched administrative survey data on economics students enrolled in two econometrics courses offered in consecutive terms at a major public university in Spain to assess the impact of lecture attendance and study time on academic performance. Using proxy variables in a cross-sectional regression setting, they find a positive…

Improving laboratory results turnaround time by reducing pre analytical phase.

PubMed

Khalifa, Mohamed; Khalid, Parwaiz

2014-01-01

Laboratory turnaround time is considered one of the most important indicators of work efficiency in hospitals, physicians always need timely results to take effective clinical decisions especially in the emergency department where these results can guide physicians whether to admit patients to the hospital, discharge them home or do further investigations. A retrospective data analysis study was performed to identify the effects of ER and Lab staff training on new routines for sample collection and transportation on the pre-analytical phase of turnaround time. Renal profile tests requested by the ER and performed in 2013 has been selected as a sample, and data about 7,519 tests were retrieved and analyzed to compare turnaround time intervals before and after implementing new routines. Results showed significant time reduction on "Request to Sample Collection" and "Collection to In Lab Delivery" time intervals with less significant improvement on the analytical phase of the turnaround time.

Apollo 16 time and motion study

NASA Technical Reports Server (NTRS)

Kubis, J. F.; Elrod, J. T.; Rusnak, R.; Barnes, J. E.; Saxon, S. C.

1972-01-01

A time and motion study is presented of astronaut lunar surface activity on Apollo 16 which consists of five distinct analyses: an evaluation of lunar mobility, a comparison of task performance in 1-g training and lunar EVA, a study of metabolic costs and adaptation, a discussion of falls, and retrieval of fallen objects. Two basic mobility patterns, the hop or canter and the traditional walking gait, were consistently utilized in longer traverses. The metabolic rates associated with these two mobility types, each used by a different astronaut, were relatively equivalent. The time to perform tasks on the lunar surface was significantly longer (on the order of 70%) than the time to perform the same tasks during the last 1-g training session. These results corroborated the findings on Apollo 15 and were not significantly different from them. There was general improvement in lunar EVA performance upon repetition of tasks. Metabolic rate (BTU/hr.) and metabolic cost (BTU) decreased over successive EVAs. Specifically, the metabolic rate associated with riding the lunar roving vehicle (LRV) decreased by approximately 18% from EVA 1 to EVA 2 and by 15% from EVA 2 to EVA 3.

A Comparison Between the Time-Management Skills and Academic Performance of Mature and Traditional-Entry University Students.

ERIC Educational Resources Information Center

Trueman, Mark; Hartley, James

1996-01-01

A study of first-time university students, aged under 21 (n=172), 21-25 (n=50), and over 25 years (n=71) found that women in general reported more time-management skills than men and that older students had better time-management skills than younger students. Academic performance was only modestly predicted by age and scores on one component of…

Memory Shaped by Age Stereotypes over Time

PubMed Central

Zonderman, Alan B.; Slade, Martin D.; Ferrucci, Luigi

2012-01-01

Objectives. Previous studies showed that negative self-stereotypes detrimentally affect the cognitive performance of marginalized group members; however, these findings were confined to short-term experiments. In the present study, we considered whether stereotypes predicted memory over time, which had not been previously examined. We also considered whether self-relevance increased the influence of stereotypes on memory over time. Method. Multiple waves of memory performance were analyzed using individual growth models. The sample consisted of 395 participants in the Baltimore Longitudinal Study of Aging. Results. Those with more negative age stereotypes demonstrated significantly worse memory performance over 38 years than those with less negative age stereotypes, after adjusting for relevant covariates. The decline in memory performance for those aged 60 and above was 30.2% greater for the more negative age stereotype group than for the less negative age stereotype group. Also, the impact of age stereotypes on memory was significantly greater among those for whom the age stereotypes were self-relevant. Discussion. This study shows that the adverse influence of negative self-stereotypes on cognitive performance is not limited to a short-term laboratory effect. Rather, the findings demonstrate, for the first time, that stereotypes also predict memory performance over an extended period in the community. PMID:22056832

The storm-time assessment of GNSS-SBAS performance within low latitude African region using a testbed-like platform

NASA Astrophysics Data System (ADS)

Abe, O. E.; Paparini, C.; Ngaya, R. H.; Otero Villamide, X.; Radicella, S. M.; Nava, B.

2017-09-01

A Satellite Based Augmentation System (SBAS) is designed to improve Global Navigation Satellite Systems (GNSS) in terms of integrity, accuracy, availability and continuity. The main limitation to SBAS performance optimization is the ionosphere, and this is more critical in low latitude. During geomagnetically disturbed periods the role of storm-time winds is important because they modify the atmospheric composition toward low latitudes. An index of ionospheric disturbance, the relative percentage of deviation of the vertical Total Electron Content (TEC) from the quiet level (DvTEC) at each station was evaluated to study positive and negative phases of the geomagnetic storms. The rate of change of TEC index (ROTI) over all the GNSS stations was estimated to evaluate equatorial ionospheric gradients and irregularities. From the study it is observed that the positive deviations are more frequent than negative ones. The availability map, which is the mean of the combine Vertical Protection Level (VPL) and Horizontal Protection Level (HPL) are used for the SBAS performance. The cases of moderate and minor storms studied during the months of July and October 2013 showed that the SBAS system performance during the disturbed periods depends on the local time in which the storm occurs, geographic longitude and other phenomena that need further study. During the storm-time conditions considered, three out of seven geomagnetic storms indicated good SBAS performance and exceed monthly average of the availability map, three geomagnetic storms reduced the system performance below monthly average while one does not have effect on SBAS system performance in respect to monthly average. The present study indicates ROTI as a better proxy than geomagnetic indices for the assessment of storm-time effects on GNSS-SBAS performance.

Time-reversal imaging for classification of submerged elastic targets via Gibbs sampling and the Relevance Vector Machine.

PubMed

Dasgupta, Nilanjan; Carin, Lawrence

2005-04-01

Time-reversal imaging (TRI) is analogous to matched-field processing, although TRI is typically very wideband and is appropriate for subsequent target classification (in addition to localization). Time-reversal techniques, as applied to acoustic target classification, are highly sensitive to channel mismatch. Hence, it is crucial to estimate the channel parameters before time-reversal imaging is performed. The channel-parameter statistics are estimated here by applying a geoacoustic inversion technique based on Gibbs sampling. The maximum a posteriori (MAP) estimate of the channel parameters are then used to perform time-reversal imaging. Time-reversal implementation requires a fast forward model, implemented here by a normal-mode framework. In addition to imaging, extraction of features from the time-reversed images is explored, with these applied to subsequent target classification. The classification of time-reversed signatures is performed by the relevance vector machine (RVM). The efficacy of the technique is analyzed on simulated in-channel data generated by a free-field finite element method (FEM) code, in conjunction with a channel propagation model, wherein the final classification performance is demonstrated to be relatively insensitive to the associated channel parameters. The underlying theory of Gibbs sampling and TRI are presented along with the feature extraction and target classification via the RVM.

Undergraduate Time Use and Academic Outcomes: Results from the University of California Undergraduate Experiences Survey 2006

ERIC Educational Resources Information Center

Brint, Steven; Cantwell, Allison M.

2010-01-01

Background/Context: Previous research has established the significance of academic study time on undergraduate students' academic performance. The effects of other uses of time are, however, in dispute. Some researchers have argued that students involved in activities that require initiative and effort also perform better in class, while students…

Learning Management System Calendar Reminders and Effects on Time Management and Academic Performance

ERIC Educational Resources Information Center

Mei, Jianyang

2016-01-01

This research project uses a large research university in the Midwest as a research site to explore the time management skills of international students and analyzes how using the Course Hack, an online Learning Management System (LMS) calendar tool, improves participants' time management skills and positively impacts their academic performance,…

Time-on-task effects in children with and without ADHD: depletion of executive resources or depletion of motivation?

PubMed

Dekkers, Tycho J; Agelink van Rentergem, Joost A; Koole, Alette; van den Wildenberg, Wery P M; Popma, Arne; Bexkens, Anika; Stoffelsen, Reino; Diekmann, Anouk; Huizenga, Hilde M

2017-12-01

Children with attention-deficit/hyperactivity disorder (ADHD) are characterized by deficits in their executive functioning and motivation. In addition, these children are characterized by a decline in performance as time-on-task increases (i.e., time-on-task effects). However, it is unknown whether these time-on-task effects should be attributed to deficits in executive functioning or to deficits in motivation. Some studies in typically developing (TD) adults indicated that time-on-task effects should be interpreted as depletion of executive resources, but other studies suggested that they represent depletion of motivation. We, therefore, investigated, in children with and without ADHD, whether there were time-on-task effects on executive functions, such as inhibition and (in)attention, and whether these were best explained by depletion of executive resources or depletion of motivation. The stop-signal task (SST), which generates both indices of inhibition (stop-signal reaction time) and attention (reaction time variability and errors), was administered in 96 children (42 ADHD, 54 TD controls; aged 9-13). To differentiate between depletion of resources and depletion of motivation, the SST was administered twice. Half of the participants was reinforced during second task performance, potentially counteracting depletion of motivation. Multilevel analyses indicated that children with ADHD were more affected by time-on-task than controls on two measures of inattention, but not on inhibition. In the ADHD group, reinforcement only improved performance on one index of attention (i.e., reaction time variability). The current findings suggest that time-on-task effects in children with ADHD occur specifically in the attentional domain, and seem to originate in both depletion of executive resources and depletion of motivation. Clinical implications for diagnostics, psycho-education, and intervention are discussed.

Effects of Sport-Specific Training Intensity on Sleep Patterns and Psychomotor Performance in Adolescent Athletes.

PubMed

Suppiah, Haresh T; Low, Chee Yong; Chia, Michael

2016-11-01

Adolescent student-athletes face time constraints due to athletic and scholastic commitments, resulting in habitually shortened nocturnal sleep durations. However, there is a dearth of research on the effects of sleep debt on student-athlete performance. The study aimed to (i) examine the habitual sleep patterns (actigraphy) of high-level student-athletes during a week of training and academic activities, (ii) ascertain the effects of habitual sleep durations experienced by high-level student-athletes on psychomotor performance, and (iii) examine the impact of sport training intensities on the sleep patterns of high-level student-athletes that participate in low and high intensity sports. Sleep patterns of 29 high-level student-athletes (14.7 ± 1.3 yrs) were monitored over 7 days. A psychomotor vigilance task was administered on weekdays to ascertain the effects of habitual sleep durations. Weekend total sleep time was longer than weekdays along with a delay in bedtime, and waketimes. Psychomotor vigilance reaction times on Monday were faster than on Thursday and Friday, with reaction times on Tuesday also faster than on Friday. False starts and lapses were greater on Friday compared with Monday. There was a negative impact of sleep debt on student-athletes' psychomotor performance.

Motor intensive anti-gravity training improves performance in dynamic balance related tasks in persons with Parkinson's disease.

PubMed

Malling, Anne Sofie B; Jensen, Bente R

2016-01-01

Recent studies indicate that the effect of training on motor performance in persons with Parkinson's disease (PDP) is dependent on motor intensity. However, training of high motor intensity can be hard to apply in PDP due to e.g. bradykinesia, rigidity, tremor and postural instability. Therefore, the aim was to study the effect of motor intensive training performed in a safe anti-gravity environment using lower-body positive pressure (LBPP) technology on performance during dynamic balance related tasks. Thirteen male PDP went through an 8-week control period followed by 8 weeks of motor intensive antigravity training. Seventeen healthy males constituted a control group (CON). Performance during a five repetition sit-to-stand test (STS; sagittal plane) and a dynamic postural balance test (DPB; transversal plane) was evaluated. Effect measures were completion time, functional rates of force development, directional changes and force variance. STS completion time improved by 24% to the level of CON which was explained by shorter sitting-time and standing-time and larger numeric rate of force change during lowering to the chair, indicating faster vertical directional change and improved relaxation. DPB completion time tended to improve and was accompanied by improvements of functional medial and lateral rates of force development and higher vertical force variance during DPB. Our results suggest that the performance improvements may relate to improved inter-limb coordination. It is concluded that 8 weeks of motor intensive training in a safe LBPP environment improved performance during dynamic balance related tasks in PDP. Copyright © 2015 Elsevier B.V. All rights reserved.

The impact of crosstalk on three-dimensional laparoscopic performance and workload.

PubMed

Sakata, Shinichiro; Grove, Philip M; Watson, Marcus O; Stevenson, Andrew R L

2017-10-01

This is the first study to explore the effects of crosstalk from 3D laparoscopic displays on technical performance and workload. We studied crosstalk at magnitudes that may have been tolerated during laparoscopic surgery. Participants were 36 voluntary doctors. To minimize floor effects, participants completed their surgery rotations, and a laparoscopic suturing course for surgical trainees. We used a counterbalanced, within-subjects design in which participants were randomly assigned to complete laparoscopic tasks in one of six unique testing sequences. In a simulation laboratory, participants were randomly assigned to complete laparoscopic 'navigation in space' and suturing tasks in three viewing conditions: 2D, 3D without ghosting and 3D with ghosting. Participants calibrated their exposure to crosstalk as the maximum level of ghosting that they could tolerate without discomfort. The Randot® Stereotest was used to verify stereoacuity. The study performance metric was time to completion. The NASA TLX was used to measure workload. Normal threshold stereoacuity (40-20 second of arc) was verified in all participants. Comparing optimal 3D with 2D viewing conditions, mean performance times were 2.8 and 1.6 times faster in laparoscopic navigation in space and suturing tasks respectively (p< .001). Comparing optimal 3D with suboptimal 3D viewing conditions, mean performance times were 2.9 times faster in both tasks (p< .001). Mean workload in 2D was 1.5 and 1.3 times greater than in optimal 3D viewing, for navigation in space and suturing tasks respectively (p< .001). Mean workload associated with suboptimal 3D was 1.3 times greater than optimal 3D in both laparoscopic tasks (p< .001). There was no significant relationship between the magnitude of ghosting score, laparoscopic performance and workload. Our findings highlight the advantages of 3D displays when used optimally, and their shortcomings when used sub-optimally, on both laparoscopic performance and workload.

Conducting an acute intense interval exercise session during the Ramadan fasting month: what is the optimal time of the day?

PubMed

Aziz, Abdul Rashid; Chia, Michael Yong Hwa; Low, Chee Yong; Slater, Gary John; Png, Weileen; Teh, Kong Chuan

2012-10-01

This study examines the effects of Ramadan fasting on performance during an intense exercise session performed at three different times of the day, i.e., 08:00, 18:00, and 21:00 h. The purpose was to determine the optimal time of the day to perform an acute high-intensity interval exercise during the Ramadan fasting month. After familiarization, nine trained athletes performed six 30-s Wingate anaerobic test (WAnT) cycle bouts followed by a time-to-exhaustion (T(exh)) cycle on six separate randomized and counterbalanced occasions. The three time-of-day nonfasting (control, CON) exercise sessions were performed before the Ramadan month, and the three corresponding time-of-day Ramadan fasting (RAM) exercise sessions were performed during the Ramadan month. Note that the 21:00 h session during Ramadan month was conducted in the nonfasted state after the breaking of the day's fast. Total work (TW) completed during the six WAnT bouts was significantly lower during RAM compared to CON for the 08:00 and 18:00 h (p < .017; effect size [d] = .55 [small] and .39 [small], respectively) sessions, but not for the 21:00 h (p = .03, d = .18 [trivial]) session. The T(exh) cycle duration was significantly shorter during RAM than CON in the 18:00 (p < .017, d = .93 [moderate]) session, but not in the 08:00 (p = .03, d = .57 [small]) and 21:00 h (p = .96, d = .02 [trivial]) sessions. In conclusion, Ramadan fasting had a small to moderate, negative impact on quality of performance during an acute high-intensity exercise session, particularly during the period of the daytime fast. The optimal time to conduct an acute high-intensity exercise session during the Ramadan fasting month is in the evening, after the breaking of the day's fast.

Motor and Gaze Behaviors of Youth Basketball Players Taking Contested and Uncontested Jump Shots

PubMed Central

van Maarseveen, Mariëtte J. J.; Oudejans, Raôul R. D.

2018-01-01

In this study, we examined the effects of a defender contesting jump shots on performance and gaze behaviors of basketball players taking jump shots. Thirteen skilled youth basketball players performed 48 shots from about 5 m from the basket; 24 uncontested and 24 contested. The participants wore mobile eye tracking glasses to measure their gaze behavior. As expected, an approaching defender trying to contest the shot led to significant changes in movement execution and gaze behavior including shorter shot execution time, longer jump time, longer ball flight time, later final fixation onset, and longer fixation on the defender. Overall, no effects were found for shooting accuracy. However, the effects on shot accuracy were not similar for all participants: six participants showed worse performance and six participants showed better performance in the contested compared to the uncontested condition. These changes in performance were accompanied by differences in gaze behavior. The participants with worse performance showed shorter absolute and relative final fixation duration and a tendency for an earlier final fixation offset in the contested condition compared to the uncontested condition, whereas gaze behavior of the participants with better performance for contested shots was relatively unaffected. The results confirm that a defender contesting the shot is a relevant constraint for basketball shooting suggesting that representative training designs should also include contested shots, and more generally other constraints that are representative of the actual performance setting such as time or mental pressure. PMID:29867671

Effects of computing time delay on real-time control systems

NASA Technical Reports Server (NTRS)

Shin, Kang G.; Cui, Xianzhong

1988-01-01

The reliability of a real-time digital control system depends not only on the reliability of the hardware and software used, but also on the speed in executing control algorithms. The latter is due to the negative effects of computing time delay on control system performance. For a given sampling interval, the effects of computing time delay are classified into the delay problem and the loss problem. Analysis of these two problems is presented as a means of evaluating real-time control systems. As an example, both the self-tuning predicted (STP) control and Proportional-Integral-Derivative (PID) control are applied to the problem of tracking robot trajectories, and their respective effects of computing time delay on control performance are comparatively evaluated. For this example, the STP (PID) controller is shown to outperform the PID (STP) controller in coping with the delay (loss) problem.

Can a senior house officer's time be used more effectively?

PubMed

Mitchell, J; Hayhurst, C; Robinson, S M

2004-09-01

To determine the amount of time senior house officers (SHO) spent performing tasks that could be delegated to a technician or administrative assistant and therefore to quantify the expected benefit that could be obtained by employing such physicians' assistants (PA). SHOs working in the emergency department were observed for one week by pre-clinical students who had been trained to code and time each task performed by SHOs. Activity was grouped into four categories (clinical, technical, administrative, and other). Those activities in the technical and administrative categories were those we believed could be performed by a PA. The SHOs worked 430 hours in total, of which only 25 hours were not coded due to lack of an observer. Of the 405 hours observed 86.2% of time was accounted for by the various codes. The process of taking a history and examining patients accounted for an average of 22% of coded time. Writing the patient's notes accounted for an average of 20% of coded time. Discussion with relatives and patients accounted for 4.7% of coded time and performing procedures accounted for 5.2% of coded time. On average across all shifts, 15% of coded time was spent doing either technical or administrative tasks. In this department an average of 15% of coded SHOs working time was spent performing administrative and technical tasks, rising to 17% of coded time during a night shift. This is equivalent to an average time of 78 minutes per 10 hour shift/SHO. Most tasks included in these categories could be performed by PAs thus potentially decreasing patient waiting times, improving risk management, allowing doctors to spend more time with their patients, and possibly improving doctors' training.

Effects of working memory load and repeated scenario exposure on emergency braking performance.

PubMed

Engström, Johan; Aust, Mikael Ljung; Viström, Matias

2010-10-01

The objective of the present study was to examine the effect of working memory load on drivers' responses to a suddenly braking lead vehicle and whether this effect (if any) is moderated by repeated scenario exposure. Several experimental studies have found delayed braking responses to lead vehicle braking events during concurrent performance of nonvisual, working memory-loading tasks, such as hands-free phone conversation. However, the common use of repeated, and hence somewhat expected, braking events may undermine the generalizability of these results to naturalistic, unexpected, emergency braking scenarios. A critical lead vehicle braking scenario was implemented in a fixed-based simulator.The effects of working memory load and repeated scenario exposure on braking performance were examined. Brake response time was decomposed into accelerator pedal release time and accelerator-to-brake pedal movement time. Accelerator pedal release times were strongly reduced with repeated scenario exposure and were delayed by working memory load with a small but significant amount (178 ms).The two factors did not interact. There were no effects on accelerator-to-brake pedal movement time. The results suggest that effects of working memory load on response performance obtained from repeated critical lead vehicle braking scenarios may be validly generalized to real world unexpected events. The results have important implications for the interpretation of braking performance in experimental settings, in particular in the context of safety-related evaluation of in-vehicle information and communication technologies.

Does a 3D Image Improve Laparoscopic Motor Skills?

PubMed

Folaranmi, Semiu Eniola; Partridge, Roland W; Brennan, Paul M; Hennessey, Iain A M

2016-08-01

To quantitatively determine whether a three-dimensional (3D) image improves laparoscopic performance compared with a two-dimensional (2D) image. This is a prospective study with two groups of participants: novices (5) and experts (5). Individuals within each group undertook a validated laparoscopic task on a box simulator, alternating between 2D and a 3D laparoscopic image until they had repeated the task five times with each imaging modality. A dedicated motion capture camera was used to determine the time taken to complete the task (seconds) and instrument distance traveled (meters). Among the experts, the mean time taken to perform the task on the 3D image was significantly quicker than on the 2D image, 40.2 seconds versus 51.2 seconds, P < .0001. Among the novices, the mean task time again was significantly quicker on the 3D image, 56.4 seconds versus 82.7 seconds, P < .0001. There was no significant difference in the mean time it took a novice to perform the task using a 3D camera compared with an expert on a 2D camera, 56.4 seconds versus 51.3 seconds, P = .3341. The use of a 3D image confers a significant performance advantage over a 2D camera in quantitatively measured laparoscopic skills for both experts and novices. The use of a 3D image appears to improve a novice's performance to the extent that it is not statistically different from an expert using a 2D image.

[Effects of anxiety and the COMT gene on cortical evoked potentials and performance effectiveness of selective attention].

PubMed

Alfimova, M V; Golimbet, V E; Lebedeva, I S; Korovaĭtseva, G I; Lezheĭko, T V

2014-01-01

We studied influence of the anxiety-related trait Harm Avoidance and the COMT gene, which is an important modulator of prefrontal functioning, on event-related potentials in oddball paradigm and performance effectiveness of selective attention. For 50 individuals accuracy and time of searching words among letters at any desired rate and then under an instruction to perform the task as quickly and accurate as possible were measured. Scores on the Harm Avoidance scale from Cloninger's Temperament and Character Inventory, N100 and P300 parameters, and COMTVa1158Met genotypes were obtained for them as well. Searching accuracy and time were mainly related to N100 amplitude. The COMT genotype and Harm Avoidance did not affect N100 amplitude; however, the N100 amplitude modulated their effects on accuracy and time dynamics. Harm Avoidance was positively correlated with P300 latency. The results suggest that anxiety and the COMT gene effects on performance effectiveness of selective attention depend on cognitive processes reflected in N100 parameters.

Time-varying delays compensation algorithm for powertrain active damping of an electrified vehicle equipped with an axle motor during regenerative braking

NASA Astrophysics Data System (ADS)

Zhang, Junzhi; Li, Yutong; Lv, Chen; Gou, Jinfang; Yuan, Ye

2017-03-01

The flexibility of the electrified powertrain system elicits a negative effect upon the cooperative control performance between regenerative and hydraulic braking and the active damping control performance. Meanwhile, the connections among sensors, controllers, and actuators are realized via network communication, i.e., controller area network (CAN), that introduces time-varying delays and deteriorates the control performances of the closed-loop control systems. As such, the goal of this paper is to develop a control algorithm to cope with all these challenges. To this end, the models of the stochastic network induced time-varying delays, based on a real in-vehicle network topology and on a flexible electrified powertrain, were firstly built. In order to further enhance the control performances of active damping and cooperative control of regenerative and hydraulic braking, the time-varying delays compensation algorithm for the electrified powertrain active damping during regenerative braking was developed based on a predictive scheme. The augmented system is constructed and the H∞ performance is analyzed. Based on this analysis, the control gains are derived by solving a nonlinear minimization problem. The simulations and hardware-in-loop (HIL) tests were carried out to validate the effectiveness of the developed algorithm. The test results show that the active damping and cooperative control performances are enhanced significantly.

Analysing playing using the note-time playing path.

PubMed

de Graaff, Deborah L E; Schubert, Emery

2011-03-01

This article introduces a new method of data analysis that represents the playing of written music as a graph. The method, inspired by Miklaszewski, charts low-level note timings from a sound recording of a single-line instrument using high-precision audio-to-MIDI conversion software. Note onset times of pitch sequences are then plotted against the score-predicted timings to produce a Note-Time Playing Path (NTPP). The score-predicted onset time of each sequentially performed note (horizontal axis) unfolds in performed time down the page (vertical axis). NTPPs provide a visualisation that shows (1) tempo variations, (2) repetitive practice behaviours, (3) segmenting of material, (4) precise note time positions, and (5) time spent on playing or not playing. The NTPP can provide significant new insights into behaviour and cognition of music performance and may also be used to complement established traditional approaches such as think-alouds, interviews, and video coding.

A method to evaluate process performance by integrating time and resources

NASA Astrophysics Data System (ADS)

Wang, Yu; Wei, Qingjie; Jin, Shuang

2017-06-01

The purpose of process mining is to improve the existing process of the enterprise, so how to measure the performance of the process is particularly important. However, the current research on the performance evaluation method is still insufficient. The main methods of evaluation are mainly using time or resource. These basic statistics cannot evaluate process performance very well. In this paper, a method of evaluating the performance of the process based on time dimension and resource dimension is proposed. This method can be used to measure the utilization and redundancy of resources in the process. This paper will introduce the design principle and formula of the evaluation algorithm. Then, the design and the implementation of the evaluation method will be introduced. Finally, we will use the evaluating method to analyse the event log from a telephone maintenance process and propose an optimization plan.

DuPont qualicon BAX system real-time PCR assay for Escherichia coli O157:H7.

PubMed

Burns, Frank; Fleck, Lois; Andaloro, Bridget; Davis, Eugene; Rohrbeck, Jeff; Tice, George; Wallace, Morgan

2011-01-01

Evaluations were conducted to test the performance of the BAX System Real-Time PCR assay, which was certified as Performance Tested Method 031002 for screening E. coli O157:H7 in ground beef, beef trim, spinach, and lettuce. Method comparison studies performed on samples with low-level inoculates showed that the BAX System demonstrates a sensitivity equivalent or superior to the FDA-BAM and the USDA-FSIS culture methods, but with a significantly shorter time to result. Tests to evaluate inclusivity and exclusivity returned no false-negative and no false-positive results on a diverse panel of isolates, and tests for lot-to-lot variability and tablet stability demonstrated consistent performance. Ruggedness studies determined that none of the factors examined affect the performance of the assay. An accelerated shelf life study determined an initial 36 month shelf life for the test kit.

Examining the relationship between endogenous pain modulation capacity and endurance exercise performance.

PubMed

Flood, Andrew; Waddington, Gordon; Cathcart, Stuart

2017-01-01

The aim of the current study was to examine the relationship between pain modulatory capacity and endurance exercise performance. Twenty-seven recreationally active males between 18 and 35 years of age participated in the study. Pain modulation was assessed by examining the inhibitory effect of a noxious conditioning stimulus (cuff occlusion) on the perceived intensity of a second noxious stimulus (pressure pain threshold). Participants completed two, maximal voluntary contractions followed by a submaximal endurance time task. Both performance tasks involved an isometric contraction of the non-dominant leg. The main analysis uncovered a correlation between pain modulatory capacity and performance on the endurance time task (r = -.425, p = .027), such that those with elevated pain modulation produced longer endurance times. These findings are the first to demonstrate the relationship between pain modulation responses and endurance exercise performance.

Impact of 2D and 3D vision on performance of novice subjects using da Vinci robotic system.

PubMed

Blavier, A; Gaudissart, Q; Cadière, G B; Nyssen, A S

2006-01-01

The aim of this study was to evaluate the impact of 3D and 2D vision on performance of novice subjects using da Vinci robotic system. 224 nurses without any surgical experience were divided into two groups and executed a motor task with the robotic system in 2D for one group and with the robotic system in 3D for the other group. Time to perform the task was recorded. Our data showed significant better time performance in 3D view (24.67 +/- 11.2) than in 2D view (40.26 +/- 17.49, P < 0.001). Our findings emphasized the advantage of 3D vision over 2D view in performing surgical task, encouraging the development of efficient and less expensive 3D systems in order to improve the accuracy of surgical gesture, the resident training and the operating time.

Impact of hybrid delivery of education on student academic performance and the student experience.

PubMed

Congdon, Heather Brennan; Nutter, Douglas A; Charneski, Lisa; Butko, Peter

2009-11-12

To compare student academic performance and the student experience in the first-year doctor of pharmacy (PharmD) program between the main and newly opened satellite campuses of the University of Maryland. Student performance indicators including graded assessments, course averages, cumulative first-year grade point average (GPA), and introductory pharmacy practice experience (IPPE) evaluations were analyzed retrospectively. Student experience indicators were obtained via an online survey instrument and included involvement in student organizations; time-budgeting practices; and stress levels and their perceived effect on performance. Graded assessments, course averages, GPA, and IPPE evaluations were indistinguishable between campuses. Students' time allocation was not different between campuses, except for time spent attending class and watching lecture videos. There was no difference between students' stress levels at each campus. The implementation of a satellite campus to expand pharmacy education yielded academic performance and student engagement comparable to those from traditional delivery methods.

Delayed benefit of naps on motor learning in preschool children.

PubMed

Desrochers, Phillip C; Kurdziel, Laura B F; Spencer, Rebecca M C

2016-03-01

Sleep benefits memory consolidation across a variety of domains in young adults. However, while declarative memories benefit from sleep in young children, such improvements are not consistently seen for procedural skill learning. Here we examined whether performance improvements on a procedural task, although not immediately observed, are evident after a longer delay when augmented by overnight sleep (24 h after learning). We trained 47 children, aged 33-71 months, on a serial reaction time task and, using a within-subject design, evaluated performance at three time points: immediately after learning, after a daytime nap (nap condition) or equivalent wake opportunity (wake condition), and 24 h after learning. Consistent with previous studies, performance improvements following the nap did not differ from performance improvements following an equivalent interval spent awake. However, significant benefits of the nap were found when performance was assessed 24 h after learning. This research demonstrates that motor skill learning is benefited by sleep, but that this benefit is only evident after an extended period of time.

Dynamic Bus Travel Time Prediction Models on Road with Multiple Bus Routes

PubMed Central

Bai, Cong; Peng, Zhong-Ren; Lu, Qing-Chang; Sun, Jian

2015-01-01

Accurate and real-time travel time information for buses can help passengers better plan their trips and minimize waiting times. A dynamic travel time prediction model for buses addressing the cases on road with multiple bus routes is proposed in this paper, based on support vector machines (SVMs) and Kalman filtering-based algorithm. In the proposed model, the well-trained SVM model predicts the baseline bus travel times from the historical bus trip data; the Kalman filtering-based dynamic algorithm can adjust bus travel times with the latest bus operation information and the estimated baseline travel times. The performance of the proposed dynamic model is validated with the real-world data on road with multiple bus routes in Shenzhen, China. The results show that the proposed dynamic model is feasible and applicable for bus travel time prediction and has the best prediction performance among all the five models proposed in the study in terms of prediction accuracy on road with multiple bus routes. PMID:26294903

Dynamic Bus Travel Time Prediction Models on Road with Multiple Bus Routes.

PubMed

Bai, Cong; Peng, Zhong-Ren; Lu, Qing-Chang; Sun, Jian

2015-01-01

Accurate and real-time travel time information for buses can help passengers better plan their trips and minimize waiting times. A dynamic travel time prediction model for buses addressing the cases on road with multiple bus routes is proposed in this paper, based on support vector machines (SVMs) and Kalman filtering-based algorithm. In the proposed model, the well-trained SVM model predicts the baseline bus travel times from the historical bus trip data; the Kalman filtering-based dynamic algorithm can adjust bus travel times with the latest bus operation information and the estimated baseline travel times. The performance of the proposed dynamic model is validated with the real-world data on road with multiple bus routes in Shenzhen, China. The results show that the proposed dynamic model is feasible and applicable for bus travel time prediction and has the best prediction performance among all the five models proposed in the study in terms of prediction accuracy on road with multiple bus routes.

Emergency department waiting times: Do the raw data tell the whole story?

PubMed

Green, Janette; Dawber, James; Masso, Malcolm; Eagar, Kathy

2014-02-01

To determine whether there are real differences in emergency department (ED) performance between Australian states and territories. Cross-sectional analysis of 2009-10 attendances at an ED contributing to the Australian non-admitted patient ED care database. The main outcome measure was difference in waiting time across triage categories. There were more than 5.8 million ED attendances. Raw ED waiting times varied by a range of factors including jurisdiction, triage category, geographic location and hospital peer group. All variables were significant in a model designed to test the effect of jurisdiction on ED waiting times, including triage category, hospital peer group, patient socioeconomic status and patient remoteness. When the interaction between triage category and jurisdiction entered the model, it was found to have a significant effect on ED waiting times (P<0.001) and triage was also significant (P<0.001). Jurisdiction was no longer statistically significant (P=0.248 using all triage categories and 0.063 using only Australian Triage Scale 2 and 3). Although the Council of Australian Governments has adopted raw measures for its key ED performance indicators, raw waiting time statistics are misleading. There are no consistent differences in ED waiting times between states and territories after other factors are accounted for. WHAT IS KNOWN ABOUT THE TOPIC? The length of time patients wait to be treated after presenting at an ED is routinely used to measure ED performance. In national health agreements with the federal government, each state and territory in Australia is expected to meet waiting time performance targets for the five ED triage categories. The raw data indicate differences in performance between states and territories. WHAT DOES THIS PAPER ADD? Measuring ED performance using raw data gives misleading results. There are no consistent differences in ED waiting times between the states and territories after other factors are taken into account. WHAT ARE THE IMPLICATIONS FOR PRACTITIONERS? Judgements regarding differences in performance across states and territories for triage waiting times need to take into account the mix of patients and the mix of hospitals.

The effects of an exercise program on several abilities associated with driving performance in older adults.

PubMed

Marmeleira, José F; Godinho, Mário B; Fernandes, Orlando M

2009-01-01

The purpose of this study was to investigate the effects of participation in an exercise program on several abilities associated with driving performance in older adults. Thirty-two subjects were randomly assigned to either an exercise group (60-81 years, n=16) or a control group (60-82 years, n=16). The exercise program was planned to stress perceptive, cognitive, and physical abilities. It lasted 12 weeks with a periodicity of three sessions of 60 min per week. Assessments were conducted before and after the intervention on behavioral speed (in single- and dual-task conditions), visual attention, psychomotor performance, speed perception (time-to-contact), and executive functioning. Significant positive effects were found at 12-week follow-up resulting from participation in the exercise program. Behavioral speed improvements were found in reaction time, movement time, and response time (both in single- and dual-task conditions); visual attention improvements took place in speed processing and divided attention; psychomotor performance improvements occurred in lower limb mobility. These results showed that exercise is capable of enhancing several abilities relevant for driving performance and safety in older adults and, therefore, should be promoted.

Effects of increasing and decreasing physiological arousal on anticipation timing performance during competition and practice.

PubMed

Duncan, Michael J; Smith, Mike; Bryant, Elizabeth; Eyre, Emma; Cook, Kathryn; Hankey, Joanne; Tallis, Jason; Clarke, Neil; Jones, Marc V

2016-01-01

The aim of this study was to investigate if the effects of changes in physiological arousal on timing performance can be accurately predicted by the catastrophe model. Eighteen young adults (8 males, 10 females) volunteered to participate in the study following ethical approval. After familiarisation, coincidence anticipation was measured using the Bassin Anticipation Timer under four incremental exercise conditions: Increasing exercise intensity and low cognitive anxiety, increasing exercise intensity and high cognitive anxiety, decreasing exercise intensity and low cognitive anxiety and decreasing exercise intensity and high cognitive anxiety. Incremental exercise was performed on a treadmill at intensities of 30%, 50%, 70% and 90% heart rate reserve (HRR) respectively. Ratings of cognitive anxiety were taken at each intensity using the Mental Readiness Form 3 (MRF3) followed by performance of coincidence anticipation trials at speeds of 3 and 8 mph. Results indicated significant condition × intensity interactions for absolute error (AE; p = .0001) and MRF cognitive anxiety intensity scores (p = .05). Post hoc analysis indicated that there were no statistically significant differences in AE across exercise intensities in low-cognitive anxiety conditions. In high-cognitive anxiety conditions, timing performance AE was significantly poorer and cognitive anxiety higher at 90% HRR, compared to the other exercise intensities. There was no difference in timing responses at 90% HRR during competitive trials, irrespective of whether exercise intensity was increasing or decreasing. This study suggests that anticipation timing performance is negatively affected when physiological arousal and cognitive anxiety are high.

Increased reaction times and reduced response preparation already starts at middle age

PubMed Central

Wolkorte, Ria; Kamphuis, Janine; Zijdewind, Inge

2014-01-01

Generalized slowing characterizes aging and there is some evidence to suggest that this slowing already starts at midlife. This study aims to assess reaction time changes while performing a concurrent low-force and high-force motor task in young and middle-aged subjects. The high-force motor task is designed to induce muscle fatigue and thereby progressively increase the attentional demands. Twenty-five young (20–30 years, 12 males) and 16 middle-aged (35–55 years, 9 males) adults performed an auditory two-choice reaction time task (CRT) with and without a concurrent low- or high-force motor task. The CRT required subjects to respond to two different stimuli that occurred with a probability of 70 or 30%. The motor task consisted of index finger abduction, at either 10% (10%-dual-task) or 30% (30%-dual-task) of maximal voluntary force. Cognitive task performance was measured as percentage of correct responses and reaction times. Middle-aged subjects responded slower on the frequent but more accurately on the infrequent stimuli of CRT than young subjects. Both young and middle-aged subjects showed increased errors and reaction times while performing under dual-task conditions and both outcome measures increased further under fatiguing conditions. Only under 30%-dual-task demands, an age-effect on dual-task performance was present. Both single- and dual-task conditions showed that already at mid-life response preparation is seriously declined and that subjects implement different strategies to perform a CRT task. PMID:24808862

Effect of Above Real Time Training and Post Flight Feedback in Training of Novice Pilots in a PC-Based Flight Simulator

NASA Technical Reports Server (NTRS)

Khan, M. Javed; Rossi, Marcia; Heath, Bruce E.; Ali, Syed firasat; Crane, Peter; Knighten, Tremaine; Culpepper, Christi

2003-01-01

The use of Post-Flight Feedback (PFFB) and Above Real-Time Training (ARTT) while training novice pilots to perform a coordinated level turn on a PC-based flight simulator was investigated. One group trained at 1.5 ARTT followed by an equal number of flights at 2.0 ARTT; the second group experienced Real Time Training (RTT). The total number of flights for both groups was equal. Each group was further subdivided into two groups one of which was provided PFFB while the other was not. Then, all participants experienced two challenging evaluation missions in real time. Performance was assessed by comparing root-mean-square error in bank-angle and altitude. Participants in the 1.512.0 ARTT No-PFFB sequence did not show improvement in performance across training sessions. An ANOVA on performance in evaluation flights found that the PFFB groups performed significantly better than those with No-PFFB. Also, the RTT groups performed significantly better than the ARTT groups. Data from two additional groups trained under a 2.011.5 ARTT PFFB and No-PFFB regimes were collected and combined with data from the previously Trainers, Real-time simulation, Personal studied groups and reanalyzed to study the computers, Man-in-the-loop simulation influence of sequence. An ANOVA on test trials found no significant effects between groups. Under training situations involving ARTT we recommend that appropriate PFFB be provided.

Relationships of multitasking, physicians' strain, and performance: an observational study in ward physicians.

PubMed

Weigl, Matthias; Müller, Andreas; Sevdalis, Nick; Angerer, Peter

2013-03-01

Simultaneous task performance ("multitasking") is common in hospital physicians' work and is implicated as a major determinant for enhanced strain and detrimental performance. The aim was to determine the impact of multitasking by hospital physicians on their self reported strain and performance. A prospective observational time-and-motion study in a Community Hospital was conducted. Twenty-seven hospital physicians (surgical and internal specialties) were observed in 40 full-shift observations. Observed physicians reported twice on their self-monitored strain and performance during the observation time. Associations of observed multitasking events and subsequent strain and performance appraisals were calculated. About 21% of the working time physicians were engaged in simultaneous activities. The average time spent in multitasking activities correlated significantly with subsequently reported strain (r = 0.27, P = 0.018). The number of instances of multitasking activities correlated with self-monitored performance to a marginally significant level (r = 0.19, P = 0.098). Physicians who engage in multitasking activities tend to self-report better performance but at the cost of enhanced psychophysical strain. Hence, physicians do not perceive their own multitasking activities as a source for deficient performance, for example, medical errors. Readjustment of workload, improved organization of work for hospital physicians, and training programs to improve physicians' skills in dealing with multiple clinical demands, prioritization, and efficient task allocation may be useful avenues to explore to reduce the potentially negative impact of simultaneous task performance in clinical settings.

Morning-evening difference of team-handball-related short-term maximal physical performances in female team handball players.

PubMed

Mhenni, Thouraya; Michalsik, Lars Bojsen; Mejri, Mohamed Arbi; Yousfi, Narimen; Chaouachi, Anis; Souissi, Nizar; Chamari, Karim

2017-05-01

This study investigated the two different time-of-day effect on team-handball-related short-term maximal physical performances. At two different time-of-day, fifteen young female team handball players performed different physical tests: HandGrip (HG) test, Ball-Throwing Velocity (BTV) test, Modified Agility T-test (MAT) and Repeated Shuttle-Sprint and Jump Ability (RSSJA) test. Rating of perceived exertion (RPE) scale was determined following the termination of the last test. Measurements were performed at two separate testing sessions (i.e., in the morning (7:00-8:30 h) and in the early evening (17:00-18:30 h)) in a randomised and counter-balanced setting on non-consecutive days. The results showed that HG (P = 0.0013), BTV (P = 0.0027) and MAT (P < 0.001) performances were better in the evening compared with the morning. During RSSJA, both best and mean sprint times were shorter in the evening compared to the morning (P < 0.001). Moreover, during the latter test, mean jump performance was higher in the evening compared to the morning (P = 0.026). However, there was no morning-evening difference in the best jump performance during RSSJA. Likewise, jump performance decrement was not affected by the time-of-day of testing. On the other hand, RPE fluctuated, with morning nadirs and afternoon/early evening highest values. The findings suggest that in female team handball players, team-handball-related short-term maximal physical performances were better in the afternoon than in the morning.

Effects of a Flexibility/Support Intervention on Work Performance: Evidence From the Work, Family, and Health Network.

PubMed

Bray, Jeremy W; Hinde, Jesse M; Kaiser, David J; Mills, Michael J; Karuntzos, Georgia T; Genadek, Katie R; Kelly, Erin L; Kossek, Ellen E; Hurtado, David A

2018-05-01

To estimate the effects of a workplace initiative to reduce work-family conflict on employee performance. A group-randomized multisite controlled experimental study with longitudinal follow-up. An information technology firm. Employees randomized to the intervention (n = 348) and control condition (n = 345). An intervention, "Start. Transform. Achieve. Results." to enhance employees' control over their work time, to increase supervisors' support for this change, and to increase employees' and supervisors' focus on results. We estimated the effect of the intervention on 9 self-reported employee performance measures using a difference-in-differences approach with generalized linear mixed models. Performance measures included actual and expected hours worked, absenteeism, and presenteeism. This study found little evidence that an intervention targeting work-family conflict affected employee performance. The only significant effect of the intervention was an approximately 1-hour reduction in expected work hours. After Bonferroni correction, the intervention effect is marginally insignificant at 6 months and marginally significant at 12 and 18 months. The intervention reduced expected working time by 1 hour per week; effects on most other employee self-reported performance measures were statistically insignificant. When coupled with the other positive wellness and firm outcomes, this intervention may be useful for improving employee perceptions of increased access to personal time or personal wellness without sacrificing performance. The null effects on performance provide countervailing evidence to recent negative press on work-family and flex work initiatives.

The gender difference on the Mental Rotations test is not due to performance factors.

PubMed

Masters, M S

1998-05-01

Men score higher than women on the Mental Rotations test (MRT), and the magnitude of this gender difference is the largest of that on any spatial test. Goldstein, Haldane, and Mitchell (1990) reported finding that the gender difference on the MRT disappears when "performance factors" are controlled--specifically, when subjects are allowed sufficient time to attempt all items on the test or when a scoring procedure that controls for the number of items attempted is used. The present experiment also explored whether eliminating these performance factors results in a disappearance of the gender difference on the test. Male and female college students were allowed a short time period or unlimited time on the MRT. The tests were scored according to three different procedures. The results showed no evidence that the gender difference on the MRT was affected by the scoring method or the time limit. Regardless of the scoring procedure, men scored higher than women, and the magnitude of the gender difference persisted undiminished when subjects completed all items on the test. Thus there was no evidence that performance factors produced the gender difference on the MRT. These results are consistent with the results of other investigators who have attempted to replicate Goldstein et al.'s findings.

Altered Running Economy Directly Translates to Altered Distance-Running Performance.

PubMed

Hoogkamer, Wouter; Kipp, Shalaya; Spiering, Barry A; Kram, Rodger

2016-11-01

Our goal was to quantify if small (1%-3%) changes in running economy quantitatively affect distance-running performance. Based on the linear relationship between metabolic rate and running velocity and on earlier observations that added shoe mass increases metabolic rate by ~1% per 100 g per shoe, we hypothesized that adding 100 and 300 g per shoe would slow 3000-m time-trial performance by 1% and 3%, respectively. Eighteen male sub-20-min 5-km runners completed treadmill testing, and three 3000-m time trials wearing control shoes and identical shoes with 100 and 300 g of discreetly added mass. We measured rates of oxygen consumption and carbon dioxide production and calculated metabolic rates for the treadmill tests, and we recorded overall running time for the time trials. Adding mass to the shoes significantly increased metabolic rate at 3.5 m·s by 1.11% per 100 g per shoe (95% confidence interval = 0.88%-1.35%). While wearing the control shoes, participants ran the 3000-m time trial in 626.1 ± 55.6 s. Times averaged 0.65% ± 1.36% and 2.37% ± 2.09% slower for the +100-g and +300-g shoes, respectively (P < 0.001). On the basis of a linear fit of all the data, 3000-m time increased 0.78% per added 100 g per shoe (95% confidence interval = 0.52%-1.04%). Adding shoe mass predictably degrades running economy and slows 3000-m time-trial performance proportionally. Our data demonstrate that laboratory-based running economy measurements can accurately predict changes in distance-running race performance due to shoe modifications.

Differential effects of two types of formative assessment in predicting performance of first-year medical students.

PubMed

Krasne, Sally; Wimmers, Paul F; Relan, Anju; Drake, Thomas A

2006-05-01

Formative assessments are systematically designed instructional interventions to assess and provide feedback on students' strengths and weaknesses in the course of teaching and learning. Despite their known benefits to student attitudes and learning, medical school curricula have been slow to integrate such assessments into the curriculum. This study investigates how performance on two different modes of formative assessment relate to each other and to performance on summative assessments in an integrated, medical-school environment. Two types of formative assessment were administered to 146 first-year medical students each week over 8 weeks: a timed, closed-book component to assess factual recall and image recognition, and an un-timed, open-book component to assess higher order reasoning including the ability to identify and access appropriate resources and to integrate and apply knowledge. Analogous summative assessments were administered in the ninth week. Models relating formative and summative assessment performance were tested using Structural Equation Modeling. Two latent variables underlying achievement on formative and summative assessments could be identified; a "formative-assessment factor" and a "summative-assessment factor," with the former predicting the latter. A latent variable underlying achievement on open-book formative assessments was highly predictive of achievement on both open- and closed-book summative assessments, whereas a latent variable underlying closed-book assessments only predicted performance on the closed-book summative assessment. Formative assessments can be used as effective predictive tools of summative performance in medical school. Open-book, un-timed assessments of higher order processes appeared to be better predictors of overall summative performance than closed-book, timed assessments of factual recall and image recognition.

Why are you late? Investigating the role of time management in time-based prospective memory.

PubMed

Waldum, Emily R; McDaniel, Mark A

2016-08-01

Time-based prospective memory tasks (TBPM) are those that are to be performed at a specific future time. Contrary to typical laboratory TBPM tasks (e.g., hit the Z key every 5 min), many real-world TBPM tasks require more complex time-management processes. For instance, to attend an appointment on time, one must estimate the duration of the drive to the appointment and then use this estimate to create and execute a secondary TBPM intention (e.g., "I need to start driving by 1:30 to make my 2:00 appointment on time"). Future under- and overestimates of drive time can lead to inefficient TBPM performance with the former lending to missed appointments and the latter to long stints in the waiting room. Despite the common occurrence of complex TBPM tasks in everyday life, to date, no studies have investigated how components of time management, including time estimation, affect behavior in such complex TBPM tasks. Therefore, the current study aimed to investigate timing biases in both older and younger adults and, further, to determine how such biases along with additional time management components including planning and plan fidelity influence complex TBPM performance. Results suggest for the first time that younger and older adults do not always utilize similar timing strategies, and as a result, can produce differential timing biases under the exact same environmental conditions. These timing biases, in turn, play a vital role in how efficiently both younger and older adults perform a later TBPM task that requires them to utilize their earlier time estimate. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Postural stability, clicker reaction time and bow draw force predict performance in elite recurve archery.

PubMed

Spratford, Wayne; Campbell, Rhiannon

2017-06-01

Recurve archery is an Olympic sport that requires extreme precision, upper body strength and endurance. The purpose of this research was to quantify how postural stability variables both pre- and post-arrow release, draw force, flight time, arrow length and clicker reaction time, collectively, impacted on the performance or scoring outcomes in elite recurve archery athletes. Thirty-nine elite-level recurve archers (23 male and 16 female; mean age = 24.7 ± 7.3 years) from four different countries volunteered to participate in this study prior to competing at a World Cup event. An AMTI force platform (1000Hz) was used to obtain centre of pressure (COP) measurements 1s prior to arrow release and 0.5s post-arrow release. High-speed footage (200Hz) allowed for calculation of arrow flight time and score. Results identified clicker reaction time, draw force and maximum sway speed as the variables that best predicted shot performance. Specifically, reduced clicker reaction time, greater bow draw force and reduced postural sway speed post-arrow release were predictors of higher scoring shots. It is suggested that future research should focus on investigating shoulder muscle tremors at full draw in relation to clicker reaction time, and the effect of upper body strength interventions (specifically targeting the musculature around the shoulder girdle) on performance in recurve archers.

The JFK BIG study: the impact of LSVT BIG® on dual task walking and mobility in persons with Parkinson's disease.

PubMed

Isaacson, Sara; O'Brien, Ashley; Lazaro, Jennifer D; Ray, Arlen; Fluet, Gerard

2018-04-01

[Purpose] The aim of this study was to test the hypothesis that Lee Silverman Voice Treatment-BIG decreases the negative impact of hypokinesia on dual task performance in persons with Parkinson's disease. [Subjects and Methods] The records of 114 patients with Parkinson's admitted to outpatient rehabilitation at a suburban hospital were reviewed. Demographics and data for 8 outcome measures were extracted for subjects that completed 14 of 16 sessions of BIG. 93 of these subjects had records of pre and post-test Timed Up and Go, Timed Up and Go Motor, and Timed Up and Go Cognitive scores. Average age was 68.4 years (SD=10.6) and average disease duration was 4.9 years (SD=5.3). [Results] Subjects demonstrated statistically significant improvements for Timed Up and Go (3.3 SD=4.5), Timed Up and Go Motor (4.4 SD=5.8) and Timed Up and Go Cognitive (4.7 SD=5.4). Concurrent motor and cognitive performance remained stable. Dual task cost decreased at a statistically significant level for Timed Up and Go Cognitive (7% SD=31%) but not Motor (4% SD=32%). [Conclusion] These findings suggest that cueing strategies associated with LSVT BIG become internalized and decrease the negative impact of hypokinesia on mobility and cognitive performance while performing two tasks simultaneously in persons with Parkinson's.

Reducing adaptive optics latency using Xeon Phi many-core processors

NASA Astrophysics Data System (ADS)

Barr, David; Basden, Alastair; Dipper, Nigel; Schwartz, Noah

2015-11-01

The next generation of Extremely Large Telescopes (ELTs) for astronomy will rely heavily on the performance of their adaptive optics (AO) systems. Real-time control is at the heart of the critical technologies that will enable telescopes to deliver the best possible science and will require a very significant extrapolation from current AO hardware existing for 4-10 m telescopes. Investigating novel real-time computing architectures and testing their eligibility against anticipated challenges is one of the main priorities of technology development for the ELTs. This paper investigates the suitability of the Intel Xeon Phi, which is a commercial off-the-shelf hardware accelerator. We focus on wavefront reconstruction performance, implementing a straightforward matrix-vector multiplication (MVM) algorithm. We present benchmarking results of the Xeon Phi on a real-time Linux platform, both as a standalone processor and integrated into an existing real-time controller (RTC). Performance of single and multiple Xeon Phis are investigated. We show that this technology has the potential of greatly reducing the mean latency and variations in execution time (jitter) of large AO systems. We present both a detailed performance analysis of the Xeon Phi for a typical E-ELT first-light instrument along with a more general approach that enables us to extend to any AO system size. We show that systematic and detailed performance analysis is an essential part of testing novel real-time control hardware to guarantee optimal science results.

Resting sympatho-vagal balance is related to 10 km running performance in master endurance athletes.

PubMed

Cataldo, Angelo; Bianco, Antonino; Paoli, Antonio; Cerasola, Dario; Alagna, Saverio; Messina, Giuseppe; Zangla, Daniele; Traina, Marcello

2018-01-12

Relationships between heart rate recovery after exercise (HRR, baseline heart rate variability measures (HRV), and time to perform a 10Km running trial (t10Km) were evaluated in "master" athletes of endurance to assess whether the measured indexes may be useful for monitoring the training status of the athletes. Ten "master" athletes of endurance, aged 40-60 years, were recruited. After baseline measures of HRV, the athletes performed a graded maximal test on treadmill and HRR was measured at 1 and 2 minutes from recovery. Subsequently they performed a 10Km running trial and t10Km was related to HRV and HRR indexes. The time to perform a 10Km running trial was significantly correlated with baseline HRV indexes. No correlation was found between t10Km and HRR. Baseline HRV measures, but not HRR, were significantly correlated with the time of performance on 10km running in "master" athletes. The enhanced parasympathetic function at rest appears to be a condition to a better performance on 10km running. HRV can be simple and useful measurements for monitoring the training stratus of athletes and their physical condition in proximity of a competition.

Performance characteristics of a slagging gasifier for MHD combustor systems

NASA Technical Reports Server (NTRS)

Smith, K. O.

1979-01-01

The performance of a two stage, coal combustor concept for magnetohydrodynamic (MHD) systems was investigated analytically. The two stage MHD combustor is comprised of an entrained flow, slagging gasifier as the first stage, and a gas phase reactor as the second stage. The first stage was modeled by assuming instantaneous coal devolatilization, and volatiles combustion and char gasification by CO2 and H2O in plug flow. The second stage combustor was modeled assuming adiabatic instantaneous gas phase reactions. Of primary interest was the dependence of char gasification efficiency on first stage particle residence time. The influence of first stage stoichiometry, heat loss, coal moisture, coal size distribution, and degree of coal devolatilization on gasifier performance and second stage exhaust temperature was determined. Performance predictions indicate that particle residence times on the order of 500 msec would be required to achieve gasification efficiencies in the range of 90 to 95 percent. The use of a finer coal size distribution significantly reduces the required gasifier residence time for acceptable levels of fuel use efficiency. Residence time requirements are also decreased by increased levels of coal devolatilization. Combustor design efforts should maximize devolatilization by minimizing mixing times associated with coal injection.

Modeling time-lagged reciprocal psychological empowerment-performance relationships.

PubMed

Maynard, M Travis; Luciano, Margaret M; D'Innocenzo, Lauren; Mathieu, John E; Dean, Matthew D

2014-11-01

Employee psychological empowerment is widely accepted as a means for organizations to compete in increasingly dynamic environments. Previous empirical research and meta-analyses have demonstrated that employee psychological empowerment is positively related to several attitudinal and behavioral outcomes including job performance. While this research positions psychological empowerment as an antecedent influencing such outcomes, a close examination of the literature reveals that this relationship is primarily based on cross-sectional research. Notably, evidence supporting the presumed benefits of empowerment has failed to account for potential reciprocal relationships and endogeneity effects. Accordingly, using a multiwave, time-lagged design, we model reciprocal relationships between psychological empowerment and job performance using a sample of 441 nurses from 5 hospitals. Incorporating temporal effects in a staggered research design and using structural equation modeling techniques, our findings provide support for the conventional positive correlation between empowerment and subsequent performance. Moreover, accounting for the temporal stability of variables over time, we found support for empowerment levels as positive influences on subsequent changes in performance. Finally, we also found support for the reciprocal relationship, as performance levels were shown to relate positively to changes in empowerment over time. Theoretical and practical implications of the reciprocal psychological empowerment-performance relationships are discussed. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

Sensitivity to change of the field-based Wheelchair Mobility Performance Test in wheelchair basketball.

PubMed

de Witte, Annemarie M H; Sjaarda, Fleur; Helleman, Jochem; Berger, Monique A M; van der Woude, Lucas H V; Hoozemans, Marco J M

2018-06-15

The Wheelchair Mobility Performance (WMP) test is a reliable and valid measure to assess mobility performance in wheelchair basketball. The aim of this study was to examine the sensitivity to change of the WMP test by manipulating wheelchair configurations. Sixteen wheelchair basketball players performed the WMP test 3 times in their own wheelchair: (i) without adjustments ("control condition"); (ii) with 10 kg additional mass ("weighted condition"); and (iii) with 50% reduced tyre pressure ("tyre condition"). The outcome measure was time (s). If paired t-tests were significant (p <0.05) and differences between conditions were larger than the standard error of measurement, the effect sizes (ES) were used to evaluate the sensitivity to change. ES values ≥0.2 were regarded as sensitive to change. The overall performance times for the manipulations were significantly higher than the control condition, with mean differences of 4.40 s (weight - control, ES = 0.44) and 2.81 s (tyre - control, ES = 0.27). The overall performance time on the WMP test was judged as sensitive to change. For 8 of the 15 separate tasks on the WMP test, the tasks were judged as sensitive to change for at least one of the manipulations. The WMP test can detect change in mobility performance when wheelchair configurations are manipulated.

EEG alpha spindles and prolonged brake reaction times during auditory distraction in an on-road driving study.

PubMed

Sonnleitner, Andreas; Treder, Matthias Sebastian; Simon, Michael; Willmann, Sven; Ewald, Arne; Buchner, Axel; Schrauf, Michael

2014-01-01

Driver distraction is responsible for a substantial number of traffic accidents. This paper describes the impact of an auditory secondary task on drivers' mental states during a primary driving task. N=20 participants performed the test procedure in a car following task with repeated forced braking on a non-public test track. Performance measures (provoked reaction time to brake lights) and brain activity (EEG alpha spindles) were analyzed to describe distracted drivers. Further, a classification approach was used to investigate whether alpha spindles can predict drivers' mental states. Results show that reaction times and alpha spindle rate increased with time-on-task. Moreover, brake reaction times and alpha spindle rate were significantly higher while driving with auditory secondary task opposed to driving only. In single-trial classification, a combination of spindle parameters yielded a median classification error of about 8% in discriminating the distracted from the alert driving. Reduced driving performance (i.e., prolonged brake reaction times) during increased cognitive load is assumed to be indicated by EEG alpha spindles, enabling the quantification of driver distraction in experiments on public roads without verbally assessing the drivers' mental states. Copyright © 2013 Elsevier Ltd. All rights reserved.

On time scales and time synchronization using LORAN-C as a time reference signal

NASA Technical Reports Server (NTRS)

Chi, A. R.

1974-01-01

The long term performance of the eight LORAN-C chains is presented in terms of the Coordinated Universal Time (UTC) of the U.S. Naval Observatory (USNO); and the use of the LORAN-C navigation system for maintaining the user's clock to a UTC scale is described. The atomic time scale and the UTC of several national laboratories and observatories relative to the international atomic time are reported. Typical performance of several NASA tracking station clocks, relative to the USNO master clock, is also presented.

Performance Dependences of Multiplication Layer Thickness for InP/InGaAs Avalanche Photodiodes Based on Time Domain Modeling

NASA Technical Reports Server (NTRS)

Xiao, Yegao; Bhat, Ishwara; Abedin, M. Nurul

2005-01-01

InP/InGaAs avalanche photodiodes (APDs) are being widely utilized in optical receivers for modern long haul and high bit-rate optical fiber communication systems. The separate absorption, grading, charge, and multiplication (SAGCM) structure is an important design consideration for APDs with high performance characteristics. Time domain modeling techniques have been previously developed to provide better understanding and optimize design issues by saving time and cost for the APD research and development. In this work, performance dependences on multiplication layer thickness have been investigated by time domain modeling. These performance characteristics include breakdown field and breakdown voltage, multiplication gain, excess noise factor, frequency response and bandwidth etc. The simulations are performed versus various multiplication layer thicknesses with certain fixed values for the areal charge sheet density whereas the values for the other structure and material parameters are kept unchanged. The frequency response is obtained from the impulse response by fast Fourier transformation. The modeling results are presented and discussed, and design considerations, especially for high speed operation at 10 Gbit/s, are further analyzed.

Implicit and Explicit Knowledge Both Improve Dual Task Performance in a Continuous Pursuit Tracking Task.

PubMed

Ewolds, Harald E; Bröker, Laura; de Oliveira, Rita F; Raab, Markus; Künzell, Stefan

2017-01-01

The goal of this study was to investigate the effect of predictability on dual-task performance in a continuous tracking task. Participants practiced either informed (explicit group) or uninformed (implicit group) about a repeated segment in the curves they had to track. In Experiment 1 participants practices the tracking task only, dual-task performance was assessed after by combining the tracking task with an auditory reaction time task. Results showed both groups learned equally well and tracking performance on a predictable segment in the dual-task condition was better than on random segments. However, reaction times did not benefit from a predictable tracking segment. To investigate the effect of learning under dual-task situation participants in Experiment 2 practiced the tracking task while simultaneously performing the auditory reaction time task. No learning of the repeated segment could be demonstrated for either group during the training blocks, in contrast to the test-block and retention test, where participants performed better on the repeated segment in both dual-task and single-task conditions. Only the explicit group improved from test-block to retention test. As in Experiment 1, reaction times while tracking a predictable segment were no better than reaction times while tracking a random segment. We concluded that predictability has a positive effect only on the predictable task itself possibly because of a task-shielding mechanism. For dual-task training there seems to be an initial negative effect of explicit instructions, possibly because of fatigue, but the advantage of explicit instructions was demonstrated in a retention test. This might be due to the explicit memory system informing or aiding the implicit memory system.

Improvement of Performance and Reduction of Fatigue With Low-Level Laser Therapy in Competitive Cyclists.

PubMed

Lanferdini, Fábio J; Bini, Rodrigo R; Baroni, Bruno M; Klein, Kelli D; Carpes, Felipe P; Vaz, Marco A

2018-01-01

Evidence indicates that low-level laser therapy (LLLT) minimizes fatigue effects on muscle performance. However, the ideal LLLT dosage to improve athletes'performance during sports activities such as cycling is still unclear. Therefore, the goal of this study was to investigate the effects of different LLLT dosages on cyclists'performance in time-to-exhaustion tests. In addition, the effects of LLLT on the frequency content of the EMG signals to assess fatigue mechanisms were examined. Twenty male competitive cyclists participated in a crossover, randomized, double-blind, placebo-controlled trial. They performed an incremental cycling test to exhaustion (on day 1) followed by 4 time-to-exhaustion tests (on days 2-5) at their individual maximal power output. Before each time-to-exhaustion test, different dosages of LLLT (135, 270, and 405 J/thigh, respectively) or placebo were applied at the quadriceps muscle bilaterally. Power output and muscle activation from both lower limbs were recorded throughout the tests. Increased performance in time-to-exhaustion tests was observed with the LLLT-135 J (∼22 s; P < .01), LLLT-270 J (∼13 s; P = .03), and LLLT-405 J (∼13 s; P = .02) compared to placebo (149 ± 23 s). Although LLLT-270 J and LLLT-405 J did not show significant differences in muscle activation compared with placebo, LLLT-135 J led to an increased high-frequency content compared with placebo in both limbs at the end of the exhaustion test (P ≤ .03). In conclusion, LLLT increased time to exhaustion in competitive cyclists, suggesting this intervention as a possible nonpharmacological ergogenic agent in cycling. Among the different dosages, LLLT-135 J seems to promote the best effects.

Implicit and Explicit Knowledge Both Improve Dual Task Performance in a Continuous Pursuit Tracking Task

PubMed Central

Ewolds, Harald E.; Bröker, Laura; de Oliveira, Rita F.; Raab, Markus; Künzell, Stefan

2017-01-01

The goal of this study was to investigate the effect of predictability on dual-task performance in a continuous tracking task. Participants practiced either informed (explicit group) or uninformed (implicit group) about a repeated segment in the curves they had to track. In Experiment 1 participants practices the tracking task only, dual-task performance was assessed after by combining the tracking task with an auditory reaction time task. Results showed both groups learned equally well and tracking performance on a predictable segment in the dual-task condition was better than on random segments. However, reaction times did not benefit from a predictable tracking segment. To investigate the effect of learning under dual-task situation participants in Experiment 2 practiced the tracking task while simultaneously performing the auditory reaction time task. No learning of the repeated segment could be demonstrated for either group during the training blocks, in contrast to the test-block and retention test, where participants performed better on the repeated segment in both dual-task and single-task conditions. Only the explicit group improved from test-block to retention test. As in Experiment 1, reaction times while tracking a predictable segment were no better than reaction times while tracking a random segment. We concluded that predictability has a positive effect only on the predictable task itself possibly because of a task-shielding mechanism. For dual-task training there seems to be an initial negative effect of explicit instructions, possibly because of fatigue, but the advantage of explicit instructions was demonstrated in a retention test. This might be due to the explicit memory system informing or aiding the implicit memory system. PMID:29312083

What to do? The effects of discrepancies, incentives, and time on dynamic goal prioritization.

PubMed

Schmidt, Aaron M; DeShon, Richard P

2007-07-01

This study examined factors that influence the dynamic pursuit of multiple goals over time. As hypothesized, goal-performance discrepancies were significantly related to subsequent time allocation. Greater distance from a given goal resulted in greater time subsequently allocated to that goal. In addition, the incentives offered for goal attainment determined the relative influence of discrepancies for each goal. When the incentives for each goal were equivalent, progress toward each goal exhibited equal influence, with greater time allocated to whichever goal was furthest from completion at the time. However, with an incentive available for only 1 of the 2 goals, time allocation was largely determined by progress toward the rewarded goal. Likewise, when incentives for each task differed in their approach-avoidance framing, progress toward the avoidance-framed goal was a stronger predictor of subsequent allocation than was progress toward the approach-framed goal. Finally, the influence of goal-performance discrepancies differed as a function of the time remaining for goal pursuit. The implications for future work on dynamic goal prioritization and the provision of performance incentives are discussed.

Effects of static stretching on 1-mile uphill run performance.

PubMed

Lowery, Ryan P; Joy, Jordan M; Brown, Lee E; Oliveira de Souza, Eduardo; Wistocki, David R; Davis, Gregory S; Naimo, Marshall A; Zito, Gina A; Wilson, Jacob M

2014-01-01

It is previously demonstrated that static stretching was associated with a decrease in running economy and distance run during a 30-minute time trial in trained runners. Recently, the detrimental effects of static stretching on economy were found to be limited to the first few minutes of an endurance bout. However, economy remains to be studied for its direct effects on performance during shorter endurance events. The aim of this study was to investigate the effects of static stretching on 1-mile uphill run performance, electromyography (EMG), ground contact time (GCT), and flexibility. Ten trained male distance runners aged 24 ± 5 years with an average VO2max of 64.9 ± 6.5 mL·kg-1·min-1 were recruited. Subjects reported to the laboratory on 3 separate days interspersed by 72 hours. On day 1, anthropometrics and V[Combining Dot Above]O2max were determined on a motor-driven treadmill. On days 2 and 3, subjects performed a 5-minute treadmill warm-up and either performed a series of 6 lower-body stretches for three 30-second repetitions or sat still for 10 minutes. Time to complete a 1-mile run under stretching and nonstretching conditions took place in randomized order. For the performance run, subjects were instructed to run as fast as possible at a set incline of 5% until a distance of 1 mile was completed. Flexibility from the sit and reach test, EMG, GCT, and performance, determined by time to complete the 1-mile run, were recorded after each condition. Time to complete the run was significantly less (6:51 ± 0:28 minutes) in the nonstretching condition as compared with the stretching condition (7:04 ± 0:32 minutes). A significant condition-by-time interaction for muscle activation existed, with no change in the nonstretching condition (pre 91.3 ± 11.6 mV to post 92.2 ± 12.9 mV) but increased in the stretching condition (pre 91.0 ± 11.6 mV to post 105.3 ± 12.9 mV). A significant condition-by-time interaction for GCT was also present, with no changes in the nonstretching condition (pre 211.4 ± 20.8 ms to post 212.5 ± 21.7 ms) but increased in the stretching trial (pre 210.7 ± 19.6 ms to post 237.21 ± 22.4 ms). A significant condition-by-time interaction for flexibility was found, which was increased in the stretching condition (pre 33.1 ± 2 to post 38.8 ± 2) but unchanged in the nonstretching condition (pre 33.5 ± 2 to post 35.2 ± 2). Study findings indicate that static stretching decreases performance in short endurance bouts (∼8%) while increasing GCT and muscle activation. Coaches and athletes may be at risk for decreased performance after a static stretching bout. Therefore, static stretching should be avoided before a short endurance bout.

Effect of olympic weight category on performance in the roundhouse kick to the head in taekwondo.

PubMed

Estevan, Isaac; Falco, Coral; Alvarez, Octavio; Molina-García, Javier

2012-03-01

In taekwondo, kick performance is generally measured using impact force and time. This study aimed to analyse performance in the roundhouse kick to the head according to execution distance between and within Olympic weight categories. The participants were 36 male athletes divided into three categories: featherweight (n = 10), welterweight (n = 15) and heavyweight (n = 11). Our results show that taekwondo athletes in all weight categories generate a similar relative impact force. However, the results indicate that weight has a large impact on kick performance, particularly in relation to total response time.

Effect of Olympic Weight Category on Performance in the Roundhouse Kick to the Head in Taekwondo

PubMed Central

Estevan, Isaac; Falco, Coral; Álvarez, Octavio; Molina-García, Javier

2012-01-01

In taekwondo, kick performance is generally measured using impact force and time. This study aimed to analyse performance in the roundhouse kick to the head according to execution distance between and within Olympic weight categories. The participants were 36 male athletes divided into three categories: featherweight (n = 10), welterweight (n = 15) and heavyweight (n = 11). Our results show that taekwondo athletes in all weight categories generate a similar relative impact force. However, the results indicate that weight has a large impact on kick performance, particularly in relation to total response time. PMID:23486074

Materials and processes laboratory composite materials characterization task, part 1. Damage tolerance

NASA Technical Reports Server (NTRS)

Nettles, A. T.; Tucker, D. S.; Patterson, W. J.; Franklin, S. W.; Gordon, G. H.; Hart, L.; Hodge, A. J.; Lance, D. G.; Russel, S. S.

1991-01-01

A test run was performed on IM6/3501-6 carbon-epoxy in which the material was processed, machined into specimens, and tested for damage tolerance capabilities. Nondestructive test data played a major role in this element of composite characterization. A time chart was produced showing the time the composite material spent within each Branch or Division in order to identify those areas which produce a long turnaround time. Instrumented drop weight testing was performed on the specimens with nondestructive evaluation being performed before and after the impacts. Destructive testing in the form of cross-sectional photomicrography and compression-after-impact testing were used. Results show that the processing and machining steps needed to be performed more rapidly if data on composite material is to be collected within a reasonable timeframe. The results of the damage tolerance testing showed that IM6/3501-6 is a brittle material that is very susceptible to impact damage.

Study protocol to examine the effects of spaceflight and a spaceflight analog on neurocognitive performance: extent, longevity, and neural bases.

PubMed

Koppelmans, Vincent; Erdeniz, Burak; De Dios, Yiri E; Wood, Scott J; Reuter-Lorenz, Patricia A; Kofman, Igor; Bloomberg, Jacob J; Mulavara, Ajitkumar P; Seidler, Rachael D

2013-12-18

Long duration spaceflight (i.e., 22 days or longer) has been associated with changes in sensorimotor systems, resulting in difficulties that astronauts experience with posture control, locomotion, and manual control. The microgravity environment is an important causal factor for spaceflight induced sensorimotor changes. Whether spaceflight also affects other central nervous system functions such as cognition is yet largely unknown, but of importance in consideration of the health and performance of crewmembers both in- and post-flight. We are therefore conducting a controlled prospective longitudinal study to investigate the effects of spaceflight on the extent, longevity and neural bases of sensorimotor and cognitive performance changes. Here we present the protocol of our study. This study includes three groups (astronauts, bed rest subjects, ground-based control subjects) for which each the design is single group with repeated measures. The effects of spaceflight on the brain will be investigated in astronauts who will be assessed at two time points pre-, at three time points during-, and at four time points following a spaceflight mission of six months. To parse out the effect of microgravity from the overall effects of spaceflight, we investigate the effects of seventy days head-down tilted bed rest. Bed rest subjects will be assessed at two time points before-, two time points during-, and three time points post-bed rest. A third group of ground based controls will be measured at four time points to assess reliability of our measures over time. For all participants and at all time points, except in flight, measures of neurocognitive performance, fine motor control, gait, balance, structural MRI (T1, DTI), task fMRI, and functional connectivity MRI will be obtained. In flight, astronauts will complete some of the tasks that they complete pre- and post flight, including tasks measuring spatial working memory, sensorimotor adaptation, and fine motor performance. Potential changes over time and associations between cognition, motor-behavior, and brain structure and function will be analyzed. This study explores how spaceflight induced brain changes impact functional performance. This understanding could aid in the design of targeted countermeasures to mitigate the negative effects of long-duration spaceflight.

Teaching high-performance skills using above-real-time training

NASA Technical Reports Server (NTRS)

Guckenberger, Dutch; Uliano, Kevin C.; Lane, Norman E.

1993-01-01

The above real-time training (ARTT) concept is an approach to teaching high-performance skills. ARTT refers to a training paradigm that places the operator in a simulated environment that functions at faster than normal time. It represents a departure from the intuitive, but not often supported, feeling that the best practice is determined by the training environment with the highest fidelity. This approach is hypothesized to provide greater 'transfer value' per simulation trial, by incorporating training techniques and instructional features into the simulator. Two related experiments are discussed. In the first, 25 naive male subjects performed three tank gunnery tasks on a simulator under varying levels of time acceleration (i.e., 1.0x, 1.6x, 2.0x, sequential, and mixed). They were then transferred to a standard (1.0x) condition for testing. Every accelerated condition or combination of conditions produced better training and transfer than the standard condition. Most effective was the presentation of trials at 1.0x, 1.6x, and 2.0x in a random order during training. Overall, the best ARTT group scored about 50 percent higher and trained in 25 percent less time compared to the real-time control group. In the second experiment, 24 mission-capable F-16 pilots performed three tasks on a part-task F-16A flight simulator under varying levels of time compression (i.e., 1.0x, 1.5x, 2.0x, and random). All subjects were then tested in a real-time environment. The emergency procedure (EP) task results showed increased accuracy for the ARTT groups. In testing (transfer), the ARTT groups not only performed the EP more accurately, but dealt with a simultaneous enemy significantly better than a real-time control group. Although the findings on an air combat maneuvering task and stern conversion task were mixed, most measures indicated that the ARTT groups performed better and faster than a real-time control group. Other implications for ARTT are discussed along with future research directions.

Multimodal Pilot Behavior in Multi-Axis Tracking Tasks with Time-Varying Motion Cueing Gains

NASA Technical Reports Server (NTRS)

Zaal, P. M. T; Pool, D. M.

2014-01-01

In a large number of motion-base simulators, adaptive motion filters are utilized to maximize the use of the available motion envelope of the motion system. However, not much is known about how the time-varying characteristics of such adaptive filters affect pilots when performing manual aircraft control. This paper presents the results of a study investigating the effects of time-varying motion filter gains on pilot control behavior and performance. An experiment was performed in a motion-base simulator where participants performed a simultaneous roll and pitch tracking task, while the roll and/or pitch motion filter gains changed over time. Results indicate that performance increases over time with increasing motion gains. This increase is a result of a time-varying adaptation of pilots' equalization dynamics, characterized by increased visual and motion response gains and decreased visual lead time constants. Opposite trends are found for decreasing motion filter gains. Even though the trends in both controlled axes are found to be largely the same, effects are less significant in roll. In addition, results indicate minor cross-coupling effects between pitch and roll, where a cueing variation in one axis affects the behavior adopted in the other axis.

[Nursing care time in a teaching hospital].

PubMed

Rogenski, Karin Emília; Fugulin, Fernanda Maria Togeiro; Gaidzinski, Raquel Rapone; Rogenski, Noemi Marisa Brunet

2011-03-01

This is a quantitative exploratory, descriptive study performed with the objective to identify and analyze the performance of the average time of nursing care delivered to patients of the Inpatient Units of the University Hospital at University of São Paulo (UH-USP), from 2001 to 2005. The average nursing care time delivered to patients of the referred units was identified by applying of a mathematical equation proposed in the literature, after surveying data from the Medical and Statistical Service and based on the monthly working shifts of the nursing professionals. Data analysis was performed using descriptive statistics. The average nursing care time observed in most units, despite some variations, remained stable during the analyzed period. Based on this observed stability, it is concluded that the nursing staff in the referred HU-USP units has been continuously evaluated with the purposes of maintaining the average time of assistance and, thus, the quality of the care being delivered.

Combining instruction prefetching with partial cache locking to improve WCET in real-time systems.

PubMed

Ni, Fan; Long, Xiang; Wan, Han; Gao, Xiaopeng

2013-01-01

Caches play an important role in embedded systems to bridge the performance gap between fast processor and slow memory. And prefetching mechanisms are proposed to further improve the cache performance. While in real-time systems, the application of caches complicates the Worst-Case Execution Time (WCET) analysis due to its unpredictable behavior. Modern embedded processors often equip locking mechanism to improve timing predictability of the instruction cache. However, locking the whole cache may degrade the cache performance and increase the WCET of the real-time application. In this paper, we proposed an instruction-prefetching combined partial cache locking mechanism, which combines an instruction prefetching mechanism (termed as BBIP) with partial cache locking to improve the WCET estimates of real-time applications. BBIP is an instruction prefetching mechanism we have already proposed to improve the worst-case cache performance and in turn the worst-case execution time. The estimations on typical real-time applications show that the partial cache locking mechanism shows remarkable WCET improvement over static analysis and full cache locking.

Combining Instruction Prefetching with Partial Cache Locking to Improve WCET in Real-Time Systems

PubMed Central

Ni, Fan; Long, Xiang; Wan, Han; Gao, Xiaopeng

2013-01-01

Caches play an important role in embedded systems to bridge the performance gap between fast processor and slow memory. And prefetching mechanisms are proposed to further improve the cache performance. While in real-time systems, the application of caches complicates the Worst-Case Execution Time (WCET) analysis due to its unpredictable behavior. Modern embedded processors often equip locking mechanism to improve timing predictability of the instruction cache. However, locking the whole cache may degrade the cache performance and increase the WCET of the real-time application. In this paper, we proposed an instruction-prefetching combined partial cache locking mechanism, which combines an instruction prefetching mechanism (termed as BBIP) with partial cache locking to improve the WCET estimates of real-time applications. BBIP is an instruction prefetching mechanism we have already proposed to improve the worst-case cache performance and in turn the worst-case execution time. The estimations on typical real-time applications show that the partial cache locking mechanism shows remarkable WCET improvement over static analysis and full cache locking. PMID:24386133

Performance-Based Funding & Online Learning: Maximizing Resources for Student Success

ERIC Educational Resources Information Center

Patrick, Susan; Myers, John; Silverstein, Justin; Brown, Amanda; Watson, John

2015-01-01

There is a new conversation taking place in public education on creating systemic incentives through school finance to encourage schools to innovate and be rewarded for positive student outcomes and performance. What if education funding was not based on seat-time, but on rewarding student performance? Performance-based funding is a term that…

[Which surgical technique should we perform for benign renal disease in children?].

PubMed

Saura, L; Aparicio, L García; Julià, V; Ribó, J M; Rovira, J; Rodó, J; Tarrado, X; Prat, J; Cáceres, F; Morales, L

2007-01-01

The aim of this paper is to analyze our experience in different surgical techniques to perform a nephrectomy for benign renal diseases in children. From 1993 to 2005 we have performed 98 nephrectomies. We have three groups of patients depending on the surgical technique: open nephrectomy (ON), transperitoneal laparoscopic nephrectomy (TLN) and retroperitoneal laparoscopic nephrectomy (RLN). ON was performed in 36 patients. Mean age was 3.3 years. TLN was performed in 39 patients. Mean age was 4.7 years old. RLN was performed in 23 patients. Mean age was 3.6 years old. Criteria to nephrectomy was a renographic function under 19%. We have compared the three surgical techniques in relation with surgical time and mean hospital stay. Mean operative time was 126.2 minutes in ON, 132.3 minutes in TLN and 134.1 minutes in RLN. Mean stay was 5.02 days in ON, 2.35 days in TLN and 1.86 days in RLN. The median hospital stay of the ON group is significantly longer than that of NLT and NR groups (p < 0.05). However, there are no differences related to surgical time between all the groups. Nephrectomy may be performed for benign disease in children using less invasive surgical techniques. They are associated with minimal morbidity, minimal postoperative discomfort, improve cosmesis and a shorter hospital stay. However, we haven't found differences between TLN and RLN.

Real-Time Performance Feedback for the Manual Control of Spacecraft

NASA Astrophysics Data System (ADS)

Karasinski, John Austin

Real-time performance metrics were developed to quantify workload, situational awareness, and manual task performance for use as visual feedback to pilots of aerospace vehicles. Results from prior lunar lander experiments with variable levels of automation were replicated and extended to provide insights for the development of real-time metrics. Increased levels of automation resulted in increased flight performance, lower workload, and increased situational awareness. Automated Speech Recognition (ASR) was employed to detect verbal callouts as a limited measure of subjects' situational awareness. A one-dimensional manual tracking task and simple instructor-model visual feedback scheme was developed. This feedback was indicated to the operator by changing the color of a guidance element on the primary flight display, similar to how a flight instructor points out elements of a display to a student pilot. Experiments showed that for this low-complexity task, visual feedback did not change subject performance, but did increase the subjects' measured workload. Insights gained from these experiments were applied to a Simplified Aid for EVA Rescue (SAFER) inspection task. The effects of variations of an instructor-model performance-feedback strategy on human performance in a novel SAFER inspection task were investigated. Real-time feedback was found to have a statistically significant effect of improving subject performance and decreasing workload in this complicated four degree of freedom manual control task with two secondary tasks.

Cross-Layer Modeling Framework for Energy-Efficient Resilience

DTIC Science & Technology

2014-04-01

functional block diagram of the software architecture of PEARL, which stands for: Power Efficient and Resilient Embedded Processing with Real - Time ... DVFS ). The goal of the run- time manager is to minimize power consumption, while maintaining system resilience targets (on average) and meeting... real - time performance targets. The integrated performance, power and resilience models are nothing but the analytical modeling toolkit described in

Results of SEI Independent Research and Development Projects

DTIC Science & Technology

2009-12-01

Achieving Predictable Performance in Multicore Embedded Real - Time Systems Dionisio de Niz, Jeffrey Hansen, Gabriel Moreno, Daniel Plakosh, Jorgen Hanson...Description Languages.‖ Fourth Congress on Embedded Real - Time Systems (ERTS), January 2008. [Hansson 2008b] J. Hansson, P. H. Feiler, & J. Morley...Predictable Performance in Multicore Embedded Real - Time Systems Dionisio de Niz, Jeffrey Hansen, Gabriel Moreno, Daniel Plakosh, Jorgen Hanson, Mark

Exploring the Effects of Changes in Future Time Perspective and Perceived Instrumentality on Graded Performance

ERIC Educational Resources Information Center

Eren, Altay

2009-01-01

Introduction: This study aimed to explore the possible changes in the Future Time Perspective (FTP) and Perceived Instrumentality (PI) over time as long as one academic semester, as well as to explore whether those changes in FTP and PI explained students' Graded Performance (GP) with regard to a specific course; educational psychology. Method: A…

Measuring Metacognition and Reaction Time: Further Findings on the Performances of General Education, Low-Achieving, and Institutionally Raised Students

ERIC Educational Resources Information Center

Al-Hilawani, Yasser A.; Abdullah, Ahmad A.

2010-01-01

The purpose of this study was to use the picture format to examine in depth the metacognitive performances and reaction time in general education, low-achieving, and institutionally raised students. Results revealed that institutionally raised students, unlike low-achieving students, took significantly the longest reaction time to finish the test…

14 CFR Appendix A to Part 187 - Methodology for Computation of Fees for Certification Services Performed Outside the United States

Code of Federal Regulations, 2010 CFR

2010-01-01

... persons outside the United States. (b) These rates are based on aviation safety inspector time rather than calculating a separate rate for managerial or clerical time because the inspector is the individual performing the actual service. Charging for inspector time, while building in all costs into the rate base...

14 CFR Appendix A to Part 187 - Methodology for Computation of Fees for Certification Services Performed Outside the United States

Code of Federal Regulations, 2014 CFR

2014-01-01

... persons outside the United States. (b) These rates are based on aviation safety inspector time rather than calculating a separate rate for managerial or clerical time because the inspector is the individual performing the actual service. Charging for inspector time, while building in all costs into the rate base...

14 CFR Appendix A to Part 187 - Methodology for Computation of Fees for Certification Services Performed Outside the United States

Code of Federal Regulations, 2012 CFR

2012-01-01

... persons outside the United States. (b) These rates are based on aviation safety inspector time rather than calculating a separate rate for managerial or clerical time because the inspector is the individual performing the actual service. Charging for inspector time, while building in all costs into the rate base...

14 CFR Appendix A to Part 187 - Methodology for Computation of Fees for Certification Services Performed Outside the United States

Code of Federal Regulations, 2011 CFR

2011-01-01

... persons outside the United States. (b) These rates are based on aviation safety inspector time rather than calculating a separate rate for managerial or clerical time because the inspector is the individual performing the actual service. Charging for inspector time, while building in all costs into the rate base...

A Primer on the Statistical Modelling of Learning Curves in Health Professions Education

ERIC Educational Resources Information Center

Pusic, Martin V.; Boutis, Kathy; Pecaric, Martin R.; Savenkov, Oleksander; Beckstead, Jason W.; Jaber, Mohamad Y.

2017-01-01

Learning curves are a useful way of representing the rate of learning over time. Features include an index of baseline performance (y-intercept), the efficiency of learning over time (slope parameter) and the maximal theoretical performance achievable (upper asymptote). Each of these parameters can be statistically modelled on an individual and…

Distributing Frequency And Time Signals On Optical Fibers

NASA Technical Reports Server (NTRS)

Lutes, George F.

1993-01-01

Paper reports progress in distribution of frequency and time reference signals over optical fibers. Describes current performance at frequencies of 100 MHz, 1 GHz, and 8.4 GHz. Also describes transmitting and receiving equipment and discusses tradeoff between cost and performance. Concludes with discussion of likely future development and effects of developments on systems using distributed frequency reference signals.

Performance analysis of parallel gravitational N-body codes on large GPU clusters

NASA Astrophysics Data System (ADS)

Huang, Si-Yi; Spurzem, Rainer; Berczik, Peter

2016-01-01

We compare the performance of two very different parallel gravitational N-body codes for astrophysical simulations on large Graphics Processing Unit (GPU) clusters, both of which are pioneers in their own fields as well as on certain mutual scales - NBODY6++ and Bonsai. We carry out benchmarks of the two codes by analyzing their performance, accuracy and efficiency through the modeling of structure decomposition and timing measurements. We find that both codes are heavily optimized to leverage the computational potential of GPUs as their performance has approached half of the maximum single precision performance of the underlying GPU cards. With such performance we predict that a speed-up of 200 - 300 can be achieved when up to 1k processors and GPUs are employed simultaneously. We discuss the quantitative information about comparisons of the two codes, finding that in the same cases Bonsai adopts larger time steps as well as larger relative energy errors than NBODY6++, typically ranging from 10 - 50 times larger, depending on the chosen parameters of the codes. Although the two codes are built for different astrophysical applications, in specified conditions they may overlap in performance at certain physical scales, thus allowing the user to choose either one by fine-tuning parameters accordingly.

The effects of consecutive night shifts and shift length on cognitive performance and sleepiness: a field study.

PubMed

Haidarimoghadam, Rashid; Kazemi, Reza; Motamedzadeh, Majid; Golmohamadi, Rostam; Soltanian, Alireza; Zoghipaydar, Mohamad Reza

2017-06-01

The aim of this study was to evaluate the effects of consecutive night shifts (CNS) and shift length on cognitive performance and sleepiness. This study evaluated the sleepiness and performance of 30 control room operators (CROs) working in 7 nights, 7 days, 7 days off (7N7D7O) and 30 CROs working in 4 nights, 7 days, 3 nights, 7 days off (4N7D3N7O) shift patterns in a petrochemical complex on the last night shift before swinging into the day shift. To assess cognitive performance, the n-back test, continuous performance test and simple reaction time test were employed. To assess sleepiness, the Karolinska sleepiness scale was used. Both schedules indicated that the correct responses and response times of working memory were reduced (p = 0.001), while intentional errors and sleepiness increased during the shift work (p = 0.001). CNS had a significant impact on reaction time and commission errors (p = 0.001). The main duty of CROs at a petrochemical plant is checking hazardous processes which require appropriate alertness and cognitive performance. As a result, planning for appropriate working hours and suitable number of CNS in a rotating shift system is a contribution to improving CRO performance and enhancing safety.

Terahertz radar cross section measurements.

PubMed

Iwaszczuk, Krzysztof; Heiselberg, Henning; Jepsen, Peter Uhd

2010-12-06

We perform angle- and frequency-resolved radar cross section (RCS) measurements on objects at terahertz frequencies. Our RCS measurements are performed on a scale model aircraft of size 5-10 cm in polar and azimuthal configurations, and correspond closely to RCS measurements with conventional radar on full-size objects. The measurements are performed in a terahertz time-domain system with freely propagating terahertz pulses generated by tilted pulse front excitation of lithium niobate crystals and measured with sub-picosecond time resolution. The application of a time domain system provides ranging information and also allows for identification of scattering points such as weaponry attached to the aircraft. The shapes of the models and positions of reflecting parts are retrieved by the filtered back projection algorithm.

On the Optimization of Aerospace Plane Ascent Trajectory

NASA Astrophysics Data System (ADS)

Al-Garni, Ahmed; Kassem, Ayman Hamdy

A hybrid heuristic optimization technique based on genetic algorithms and particle swarm optimization has been developed and tested for trajectory optimization problems with multi-constraints and a multi-objective cost function. The technique is used to calculate control settings for two types for ascending trajectories (constant dynamic pressure and minimum-fuel-minimum-heat) for a two-dimensional model of an aerospace plane. A thorough statistical analysis is done on the hybrid technique to make comparisons with both basic genetic algorithms and particle swarm optimization techniques with respect to convergence and execution time. Genetic algorithm optimization showed better execution time performance while particle swarm optimization showed better convergence performance. The hybrid optimization technique, benefiting from both techniques, showed superior robust performance compromising convergence trends and execution time.

Evaluation of emergency department performance – a systematic review on recommended performance and quality-in-care measures

PubMed Central

2013-01-01

Background Evaluation of emergency department (ED) performance remains a difficult task due to the lack of consensus on performance measures that reflects high quality, efficiency, and sustainability. Aim To describe, map, and critically evaluate which performance measures that the published literature regard as being most relevant in assessing overall ED performance. Methods Following the PRISMA guidelines, a systematic literature review of review articles reporting accentuated ED performance measures was conducted in the databases of PubMed, Cochrane Library, and Web of Science. Study eligibility criteria includes: 1) the main purpose was to discuss, analyse, or promote performance measures best reflecting ED performance, 2) the article was a review article, and 3) the article reported macro-level performance measures, thus reflecting an overall departmental performance level. Results A number of articles addresses this study’s objective (n = 14 of 46 unique hits). Time intervals and patient-related measures were dominant in the identified performance measures in review articles from US, UK, Sweden and Canada. Length of stay (LOS), time between patient arrival to initial clinical assessment, and time between patient arrivals to admission were highlighted by the majority of articles. Concurrently, “patients left without being seen” (LWBS), unplanned re-attendance within a maximum of 72 hours, mortality/morbidity, and number of unintended incidents were the most highlighted performance measures that related directly to the patient. Performance measures related to employees were only stated in two of the 14 included articles. Conclusions A total of 55 ED performance measures were identified. ED time intervals were the most recommended performance measures followed by patient centeredness and safety performance measures. ED employee related performance measures were rarely mentioned in the investigated literature. The study’s results allow for advancement towards improved performance measurement and standardised assessment across EDs. PMID:23938117

Effects of reaction time variability and age on brain activity during Stroop task performance.

PubMed

Tam, Angela; Luedke, Angela C; Walsh, Jeremy J; Fernandez-Ruiz, Juan; Garcia, Angeles

2015-09-01

Variability in reaction time during task performance may reflect fluctuations in attention and cause reduced performance in goal-directed tasks, yet it is unclear whether the mechanisms behind this phenomenon change with age. Using fMRI, we tested young and cognitively healthy older adults with the Stroop task to determine whether aging affects the neural mechanisms underlying intra-individual reaction time variability. We found significant between-group differences in BOLD activity modulated by reaction time. In older adults, longer reaction times were associated with greater activity in frontoparietal attentional areas, while in younger adults longer reaction times were associated with greater activity in default mode network areas. Our results suggest that the neural correlates of reaction time variability change with healthy aging, reinforcing the concept of functional plasticity to maintain high cognitive function throughout the lifespan.

ACTS Multibeam Antenna On-Orbit Performance

NASA Technical Reports Server (NTRS)

Acosta, R.; Wright, D.; Mitchell, Kenneth

1996-01-01

The Advanced Communications Technology Satellite (ACTS) launched in September 1993 introduces several new technologies including a multibeam antenna (MBA) operating at Ka-band. The MBA with fixed and rapidly reconfigurable spot beams serves users equipped with small aperture terminals within the coverage area. The antenna produces spot beams with approximately 0.3 degrees beamwidth and gains of approximately 50 dBi. A number of MBA performance evaluations have been performed since the ACTS launch. These evaluations were designed to assess MBA performance (e.g., beam pointing stability, beam shape, gain, etc.) in the space environment. The on-orbit measurements found systematic environmental perturbation to the MBA beam pointing. These perturbations were found to be imposed by satellite attitude control system, antenna and spacecraft mechanical alignments, on-orbit thermal effects, etc. As a result, the footprint coverage of the MBA may not exactly cover the intended service area at all times. This report describes the space environment effects on the ACTS MBA performance as a function of time of the day and time of the year and compensation approaches for these effects.

Command and Telemetry Latency Effects on Operator Performance during International Space Station Robotics Operations

NASA Technical Reports Server (NTRS)

Currie, Nancy J.; Rochlis, Jennifer

2004-01-01

International Space Station (ISS) operations will require the on-board crew to perform numerous robotic-assisted assembly, maintenance, and inspection activities. Current estimates for some robotically performed maintenance timelines are disproportionate and potentially exceed crew availability and duty times. Ground-based control of the ISS robotic manipulators, specifically the Special Purpose Dexterous Manipulator (SPDM), is being examined as one potential solution to alleviate the excessive amounts of crew time required for extravehicular robotic maintenance and inspection tasks.

A comparison of the effect of mobile phone use and alcohol consumption on driving simulation performance.

PubMed

Leung, Sumie; Croft, Rodney J; Jackson, Melinda L; Howard, Mark E; McKenzie, Raymond J

2012-01-01

The present study compared the effects of a variety of mobile phone usage conditions to different levels of alcohol intoxication on simulated driving performance and psychomotor vigilance. Twelve healthy volunteers participated in a crossover design in which each participant completed a simulated driving task on 2 days, separated by a 1-week washout period. On the mobile phone day, participants performed the simulated driving task under each of 4 conditions: no phone usage, a hands-free naturalistic conversation, a hands-free cognitively demanding conversation, and texting. On the alcohol day, participants performed the simulated driving task at four different blood alcohol concentration (BAC) levels: 0.00, 0.04, 0.07, and 0.10. Driving performance was assessed by variables including time within target speed range, time spent speeding, braking reaction time, speed deviation, and lateral lane position deviation. In the BAC 0.07 and 0.10 alcohol conditions, participants spent less time in the target speed range and more time speeding and took longer to brake in the BAC 0.04, 0.07, and 0.10 than in the BAC 0.00 condition. In the mobile phone condition, participants took longer to brake in the natural hands-free conversation, cognitively demanding hands-free conversation and texting conditions and spent less time in the target speed range and more time speeding in the cognitively demanding, hands-free conversation, and texting conditions. When comparing the 2 conditions, the naturalistic conversation was comparable to the legally permissible BAC level (0.04), and the cognitively demanding and texting conversations were similar to the BAC 0.07 to 0.10 results. The findings of the current laboratory study suggest that very simple conversations on a mobile phone may not represent a significant driving risk (compared to legally permissible BAC levels), whereas cognitively demanding, hands-free conversation, and particularly texting represent significant risks to driving.

A novel adaptive finite time controller for bilateral teleoperation system

NASA Astrophysics Data System (ADS)

Wang, Ziwei; Chen, Zhang; Liang, Bin; Zhang, Bo

2018-03-01

Most bilateral teleoperation researches focus on the system stability within time-delays. However, practical teleoperation tasks require high performances besides system stability, such as convergence rate and accuracy. This paper investigates bilateral teleoperation controller design with transient performances. To ensure the transient performances and system stability simultaneously, an adaptive non-singular fast terminal mode controller is proposed to achieve practical finite-time stability considering system uncertainties and time delays. In addition, a novel switching scheme is introduced, in which way the singularity problem of conventional terminal sliding manifold is avoided. Finally, numerical simulations demonstrate the effectiveness and validity of the proposed method.

Time-of-day effects on voice range profile performance in young, vocally untrained adult females.

PubMed

van Mersbergen, M R; Verdolini, K; Titze, I R

1999-12-01

Time-of-day effects on voice range profile performance were investigated in 20 vocally healthy untrained women between the ages of 18 and 35 years. Each subject produced two complete voice range profiles: one in the morning and one in the evening, about 36 hours apart. The order of morning and evening trials was counterbalanced across subjects. Dependent variables were (1) average minimum and average maximum intensity, (2) Voice range profile area and (3) center of gravity (median semitone pitch and median intensity). In this study, the results failed to reveal any clear evidence of time-of-day effects on voice range profile performance, for any of the dependent variables. However, a reliable interaction of time-of-day and trial order was obtained for average minimum intensity. Investigation of other subject populations, in particular trained vocalists or those with laryngeal lesions, is required for any generalization of the results.

Dispersion analysis for baseline reference mission 2

NASA Technical Reports Server (NTRS)

Snow, L. S.

1975-01-01

A dispersion analysis considering uncertainties (or perturbations) in platform, vehicle, and environmental parameters was performed for baseline reference mission (BRM) 2. The dispersion analysis is based on the nominal trajectory for BRM 2. The analysis was performed to determine state vector and performance dispersions (or variations) which result from the indicated uncertainties. The dispersions are determined at major mission events and fixed times from liftoff (time slices). The dispersion results will be used to evaluate the capability of the vehicle to perform the mission within a specified level of confidence and to determine flight performance reserves.

Changing behavior and accuracy with time on task in mammography screening

NASA Astrophysics Data System (ADS)

Taylor-Phillips, Sian; Jenkinson, David; Stinton, Chris; Wallis, Matthew G.; Clarke, Aileen

2017-03-01

Background: The vigilance decrement and prevalence effect both describe changes to speed and accuracy with time on task. Whilst there is much laboratory based research on these effects, little is known about whether they occur in real world mammography practice. Methods: The Changing Case Order to Optimise Patterns of Performance in Screening (CO-OPS) trial randomised 37,724 batches containing 1.2 million women attending breast screening to intervention or control (222,208 from the Midlands of England). In the control arm the batch was examined in the same order by both readers, in the intervention arm it was examined in a different order by both readers. Time taken, recall decision by both readers, and cancers detected were recorded for each case, and used to examine patterns of performance with time on task. Results: 49,575 women were recalled and 10,484 had cancer detected. Median time taken to examine each case was 35 seconds (out of cases where time taken was 10 minutes or less). The intervention did not affect overall cancer detection rates or recall rates. A more detailed analysis of the Midlands data indicates cancer detection rate did not change when reading up to 60 cases in a batch, but recall rate reduced. Time taken per case reduced with time on task, from a median 41 seconds when examining the second case in the batch to 28.5 seconds examining the 60th case. Conclusion: Reader behavior and performance systematically changes with time on task in breast screening.

The role of mental rotation and memory scanning on the performance of laparoscopic skills: a study on the effect of camera rotational angle.

PubMed

Conrad, J; Shah, A H; Divino, C M; Schluender, S; Gurland, B; Shlasko, E; Szold, A

2006-03-01

The rotational angle of the laparoscopic image relative to the true horizon has an unknown influence on performance in laparoscopic procedures. This study evaluates the effect of increasing rotational angle on surgical performance. Surgical residents (group 1) (n = 6) and attending surgeons (group 2) (n = 4) were tested on two laparoscopic skills. The tasks consisted of passing a suture through an aperture, and laparoscopic knot tying. These tasks were assessed at 15 degrees intervals between 0 degrees and 90 degrees , on three consecutive repetitions. The participant's performance was evaluated based on the time required to complete the tasks and number of errors incurred. There was an increasing deterioration in suturing performance as the degree of image rotation was increased. Participants showed a statistically significant 20-120% progressive increase in time to completion of the tasks (p = 0.004), with error rates increasing from 10% to 30% (p = 0.04) as the angle increased from 0 degrees to 90 degrees. Knot-tying performance similarly showed a decrease in performance that was evident in the less experienced surgeons (p = 0.02) but with no obvious effect on the advanced laparoscopic surgeons. When evaluated independently and as a group, both novice and experienced laparoscopic surgeons showed significant prolongation to completion of suturing tasks with increased errors as the rotational angle increased. The knot-tying task shows that experienced surgeons may be able to overcome rotational effects to some extent. This is consistent with results from cognitive neuroscience research evaluating the processing of directional information in spatial motor tasks. It appears that these tasks utilize the time-consuming processes of mental rotation and memory scanning. Optimal performance during laparoscopic procedures requires that the rotation of the camera, and thus the image, be kept to a minimum to maintain a stable horizon. New technology that corrects the rotational angle may benefit the surgeon, decrease operating time, and help to prevent adverse outcomes.

The role of musical training in emergent and event-based timing.

PubMed

Baer, L H; Thibodeau, J L N; Gralnick, T M; Li, K Z H; Penhune, V B

2013-01-01

Musical performance is thought to rely predominantly on event-based timing involving a clock-like neural process and an explicit internal representation of the time interval. Some aspects of musical performance may rely on emergent timing, which is established through the optimization of movement kinematics, and can be maintained without reference to any explicit representation of the time interval. We predicted that musical training would have its largest effect on event-based timing, supporting the dissociability of these timing processes and the dominance of event-based timing in musical performance. We compared 22 musicians and 17 non-musicians on the prototypical event-based timing task of finger tapping and on the typically emergently timed task of circle drawing. For each task, participants first responded in synchrony with a metronome (Paced) and then responded at the same rate without the metronome (Unpaced). Analyses of the Unpaced phase revealed that non-musicians were more variable in their inter-response intervals for finger tapping compared to circle drawing. Musicians did not differ between the two tasks. Between groups, non-musicians were more variable than musicians for tapping but not for drawing. We were able to show that the differences were due to less timer variability in musicians on the tapping task. Correlational analyses of movement jerk and inter-response interval variability revealed a negative association for tapping and a positive association for drawing in non-musicians only. These results suggest that musical training affects temporal variability in tapping but not drawing. Additionally, musicians and non-musicians may be employing different movement strategies to maintain accurate timing in the two tasks. These findings add to our understanding of how musical training affects timing and support the dissociability of event-based and emergent timing modes.

Validity of Treadmill-Derived Critical Speed on Predicting 5000-Meter Track-Running Performance.

PubMed

Nimmerichter, Alfred; Novak, Nina; Triska, Christoph; Prinz, Bernhard; Breese, Brynmor C

2017-03-01

Nimmerichter, A, Novak, N, Triska, C, Prinz, B, and Breese, BC. Validity of treadmill-derived critical speed on predicting 5,000-meter track-running performance. J Strength Cond Res 31(3): 706-714, 2017-To evaluate 3 models of critical speed (CS) for the prediction of 5,000-m running performance, 16 trained athletes completed an incremental test on a treadmill to determine maximal aerobic speed (MAS) and 3 randomly ordered runs to exhaustion at the [INCREMENT]70% intensity, at 110% and 98% of MAS. Critical speed and the distance covered above CS (D') were calculated using the hyperbolic speed-time (HYP), the linear distance-time (LIN), and the linear speed inverse-time model (INV). Five thousand meter performance was determined on a 400-m running track. Individual predictions of 5,000-m running time (t = [5,000-D']/CS) and speed (s = D'/t + CS) were calculated across the 3 models in addition to multiple regression analyses. Prediction accuracy was assessed with the standard error of estimate (SEE) from linear regression analysis and the mean difference expressed in units of measurement and coefficient of variation (%). Five thousand meter running performance (speed: 4.29 ± 0.39 m·s; time: 1,176 ± 117 seconds) was significantly better than the predictions from all 3 models (p < 0.0001). The mean difference was 65-105 seconds (5.7-9.4%) for time and -0.22 to -0.34 m·s (-5.0 to -7.5%) for speed. Predictions from multiple regression analyses with CS and D' as predictor variables were not significantly different from actual running performance (-1.0 to 1.1%). The SEE across all models and predictions was approximately 65 seconds or 0.20 m·s and is therefore considered as moderate. The results of this study have shown the importance of aerobic and anaerobic energy system contribution to predict 5,000-m running performance. Using estimates of CS and D' is valuable for predicting performance over race distances of 5,000 m.

PAVENET OS: A Compact Hard Real-Time Operating System for Precise Sampling in Wireless Sensor Networks

NASA Astrophysics Data System (ADS)

Saruwatari, Shunsuke; Suzuki, Makoto; Morikawa, Hiroyuki

The paper shows a compact hard real-time operating system for wireless sensor nodes called PAVENET OS. PAVENET OS provides hybrid multithreading: preemptive multithreading and cooperative multithreading. Both of the multithreading are optimized for two kinds of tasks on wireless sensor networks, and those are real-time tasks and best-effort ones. PAVENET OS can efficiently perform hard real-time tasks that cannot be performed by TinyOS. The paper demonstrates the hybrid multithreading realizes compactness and low overheads, which are comparable to those of TinyOS, through quantitative evaluation. The evaluation results show PAVENET OS performs 100 Hz sensor sampling with 0.01% jitter while performing wireless communication tasks, whereas optimized TinyOS has 0.62% jitter. In addition, PAVENET OS has a small footprint and low overheads (minimum RAM size: 29 bytes, minimum ROM size: 490 bytes, minimum task switch time: 23 cycles).

Individual Differences in Motor Timing and Its Relation to Cognitive and Fine Motor Skills

PubMed Central

Lorås, Håvard; Stensdotter, Ann-Katrin; Öhberg, Fredrik; Sigmundsson, Hermundur

2013-01-01

The present study investigated the relationship between individual differences in timing movements at the level of milliseconds and performance on selected cognitive and fine motor skills. For this purpose, young adult participants (N = 100) performed a repetitive movement task paced by an auditory metronome at different rates. Psychometric measures included the digit-span and symbol search subtasks from the Wechsler battery as well as the Raven SPM. Fine motor skills were assessed with the Purdue Pegboard test. Motor timing performance was significantly related (mean r = .3) to cognitive measures, and explained both unique and shared variance with information-processing speed of Raven's scores. No significant relations were found between motor timing measures and fine motor skills. These results show that individual differences in cognitive and motor timing performance is to some extent dependent upon shared processing not associated with individual differences in manual dexterity. PMID:23874952

Individual differences in motor timing and its relation to cognitive and fine motor skills.

PubMed

Lorås, Håvard; Stensdotter, Ann-Katrin; Öhberg, Fredrik; Sigmundsson, Hermundur

2013-01-01

The present study investigated the relationship between individual differences in timing movements at the level of milliseconds and performance on selected cognitive and fine motor skills. For this purpose, young adult participants (N = 100) performed a repetitive movement task paced by an auditory metronome at different rates. Psychometric measures included the digit-span and symbol search subtasks from the Wechsler battery as well as the Raven SPM. Fine motor skills were assessed with the Purdue Pegboard test. Motor timing performance was significantly related (mean r = .3) to cognitive measures, and explained both unique and shared variance with information-processing speed of Raven's scores. No significant relations were found between motor timing measures and fine motor skills. These results show that individual differences in cognitive and motor timing performance is to some extent dependent upon shared processing not associated with individual differences in manual dexterity.

Test techniques for determining laser ranging system performance

NASA Technical Reports Server (NTRS)

Zagwodzki, T. W.

1981-01-01

Procedures and results of an on going test program intended to evaluate laser ranging system performance levels in the field as well as in the laboratory are summarized. Tests show that laser ranging system design requires consideration of time biases and RMS jitters of individual system components. All simple Q switched lasers tested were found to be inadequate for 10 centimeter ranging systems. Timing discriminators operating over a typical 100:1 dynamic signal range may introduce as much as 7 to 9 centimeters of range bias. Time interval units commercially available today are capable of half centimeter performance and are adequate for all field systems currently deployed. Photomultipliers tested show typical tube time biases of one centimeter with single photoelectron transit time jitter of approximately 10 centimeters. Test results demonstrate that NASA's Mobile Laser Ranging System (MOBLAS) receiver configuration is limiting system performance below the 100 photoelectron level.

Impact of Official Matches on Soccer Referees' Power Performance.

PubMed

Castillo, Daniel; Yanci, Javier; Cámara, Jesús

2018-03-01

The evaluation of match officials' neuromuscular performance is now an important consideration and the vertical jump test is considered suitable for assessing lower limb power, partly because it is directly related to refereeing. The aim of this study, therefore, was to determine the effect of soccer matches on match officials' vertical jump performance by assessing various biomechanical variables. Eighteen field referees (FRs) and 36 assistant referees (ARs) who officiated in 18 official matches participated in this study. Before the match, at half time and immediately after the match, officials performed two countermovement jumps. Flight phase time (FT), maximum force production (MFpropulsion), time to production of maximum force (TMFpropulsion), production of maximum power (MP), maximum landing force (MFlanding) and time to stabilization (TTS) were calculated for all jumps. There was a tendency for match officials' jumping performance to improve after matches than beforehand (FR: effect size (ES) = 0.19 ± 0.36, possibly trivial; AR: ES = 0.07 ± 0.17, likely trivial). There were also likely small and very likely moderate differences between FRs' MP in pre-match and half-time jumps (ES = 0.46 ± 0.47) and in their pre- and post-match jumps (ES = 0.71 ± 0.48). These results indicate that refereeing soccer matches does not reduce vertical jump performance; the subsequent neuromuscular fatigue is not sufficient to affect landing technique.

Design and performance of a high spatial resolution, time-of-flight PET detector

PubMed Central

Krishnamoorthy, Srilalan; LeGeyt, Benjamin; Werner, Matthew E.; Kaul, Madhuri; Newcomer, F. M.; Karp, Joel S.; Surti, Suleman

2014-01-01

This paper describes the design and performance of a high spatial resolution PET detector with time-of-flight capabilities. With an emphasis on high spatial resolution and sensitivity, we initially evaluated the performance of several 1.5 × 1.5 and 2.0 × 2.0 mm2 and 12–15 mm long LYSO crystals read out by several appropriately sized PMTs. Experiments to evaluate the impact of reflector on detector performance were performed and the final detector consisted of a 32 × 32 array of 1.5 × 1.5 × 15 mm3 LYSO crystals packed with a diffuse reflector and read out by a single Hamamatsu 64 channel multi-anode PMT. Such a design made it compact, modular and offered a cost-effective solution to obtaining excellent energy and timing resolution. To minimize the number of readout signals, a compact front-end readout electronics that summed anode signals along each of the orthogonal directions was also developed. Experimental evaluation of detector performance demonstrates clear discrimination of the crystals within the detector. An average energy resolution (FWHM) of 12.7 ± 2.6% and average coincidence timing resolution (FWHM) of 348 ps was measured, demonstrating suitability for use in the development of a high spatial resolution time-of-flight scanner for dedicated breast PET imaging. PMID:25246711

The Effects of Different Lengths of Pretask Planning Time on L2 Learners' Oral Test Performance

ERIC Educational Resources Information Center

Li, Lanlan; Chen, Jiliang; Sun, Lan

2015-01-01

The effect of planning on second language (L2) learners' oral performance is a hotly debated topic in the field of second language acquisition. However, studies on the effect of different amounts of planning time have been quite limited, especially in a testing context. The present study investigated the effects of different lengths of…

Report on Sabbatical activities - Dr. Ronnie Shepherd - 05/25/2014 to 08/21/2014

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

Shepherd, Ronnie

2014-10-09

The sabbatical performed by Dr. Ronnie Shepherd from 05/25/2014 to 08/21/2014 had two central goals: 1) write three proposals for future collaborative experiments at Ecole Polytechnique (and possibly LLNL) 2) if laser time was granted (based on the proposal), perform a preliminary experiment in preparation for the campaign of laser time based on proposal submission.

Virtual reality, ultrasound-guided liver biopsy simulator: development and performance discrimination.

PubMed

Johnson, S J; Hunt, C M; Woolnough, H M; Crawshaw, M; Kilkenny, C; Gould, D A; England, A; Sinha, A; Villard, P F

2012-05-01

The aim of this article was to identify and prospectively investigate simulated ultrasound-guided targeted liver biopsy performance metrics as differentiators between levels of expertise in interventional radiology. Task analysis produced detailed procedural step documentation allowing identification of critical procedure steps and performance metrics for use in a virtual reality ultrasound-guided targeted liver biopsy procedure. Consultant (n=14; male=11, female=3) and trainee (n=26; male=19, female=7) scores on the performance metrics were compared. Ethical approval was granted by the Liverpool Research Ethics Committee (UK). Independent t-tests and analysis of variance (ANOVA) investigated differences between groups. Independent t-tests revealed significant differences between trainees and consultants on three performance metrics: targeting, p=0.018, t=-2.487 (-2.040 to -0.207); probe usage time, p = 0.040, t=2.132 (11.064 to 427.983); mean needle length in beam, p=0.029, t=-2.272 (-0.028 to -0.002). ANOVA reported significant differences across years of experience (0-1, 1-2, 3+ years) on seven performance metrics: no-go area touched, p=0.012; targeting, p=0.025; length of session, p=0.024; probe usage time, p=0.025; total needle distance moved, p=0.038; number of skin contacts, p<0.001; total time in no-go area, p=0.008. More experienced participants consistently received better performance scores on all 19 performance metrics. It is possible to measure and monitor performance using simulation, with performance metrics providing feedback on skill level and differentiating levels of expertise. However, a transfer of training study is required.

Criterion-based laparoscopic training reduces total training time.

PubMed

Brinkman, Willem M; Buzink, Sonja N; Alevizos, Leonidas; de Hingh, Ignace H J T; Jakimowicz, Jack J

2012-04-01

The benefits of criterion-based laparoscopic training over time-oriented training are unclear. The purpose of this study is to compare these types of training based on training outcome and time efficiency. During four training sessions within 1 week (one session per day) 34 medical interns (no laparoscopic experience) practiced on two basic tasks on the Simbionix LAP Mentor virtual-reality (VR) simulator: 'clipping and grasping' and 'cutting'. Group C (criterion-based) (N = 17) trained to reach predefined criteria and stopped training in each session when these criteria were met, with a maximum training time of 1 h. Group T (time-based) (N = 17) trained for a fixed time of 1 h each session. Retention of skills was assessed 1 week after training. In addition, transferability of skills was established using the Haptica ProMIS augmented-reality simulator. Both groups improved their performance significantly over the course of the training sessions (Wilcoxon signed ranks, P < 0.05). Both groups showed skill transferability and skill retention. When comparing the performance parameters of group C and group T, their performances in the first, the last and the retention training sessions did not differ significantly (Mann-Whitney U test, P > 0.05). The average number of repetitions needed to meet the criteria also did not differ between the groups. Overall, group C spent less time training on the simulator than did group T (74:48 and 120:10 min, respectively; P < 0.001). Group C performed significantly fewer repetitions of each task, overall and in session 2, 3 and 4. Criterion-based training of basic laparoscopic skills can reduce the overall training time with no impact on training outcome, transferability or retention of skills. Criterion-based should be the training of choice in laparoscopic skills curricula.

Virtual Reality Simulation as a Tool to Monitor Surgical Performance Indicators: VIRESI Observational Study.

PubMed

Muralha, Nuno; Oliveira, Manuel; Ferreira, Maria Amélia; Costa-Maia, José

2017-05-31

Virtual reality simulation is a topic of discussion as a complementary tool to traditional laparoscopic surgical training in the operating room. However, it is unclear whether virtual reality training can have an impact on the surgical performance of advanced laparoscopic procedures. Our objective was to assess the ability of the virtual reality simulator LAP Mentor to identify and quantify changes in surgical performance indicators, after LAP Mentor training for digestive anastomosis. Twelve surgeons from Centro Hospitalar de São João in Porto (Portugal) performed two sessions of advanced task 5: anastomosis in LAP Mentor, before and after completing the tutorial, and were evaluated on 34 surgical performance indicators. The results show that six surgical performance indicators significantly changed after LAP Mentor training. The surgeons performed the task significantly faster as the median 'total time' significantly reduced (p < 0.05) from 759.5 to 523.5 seconds. Significant decreases (p < 0.05) were also found in median 'total needle loading time' (303.3 to 107.8 seconds), 'average needle loading time' (38.5 to 31.0 seconds), 'number of passages in which the needle passed precisely through the entrance dots' (2.5 to 1.0), 'time the needle was held outside the visible field' (20.9 to 2.4 seconds), and 'total time the needle-holders' ends are kept outside the predefined operative field' (88.2 to 49.6 seconds). This study raises the possibility of using virtual reality training simulation as a benchmark tool to assess the surgical performance of Portuguese surgeons. LAP Mentor is able to identify variations in surgical performance indicators of digestive anastomosis.

Spanish version of the Time Management Behavior Questionnaire for university students.

PubMed

García-Ros, Rafael; Pérez-González, Francisco

2012-11-01

The main objective of the study is to analyze the psychometric properties and predictive capacity on academic performance in university contexts of a Spanish adaptation of the Time Management Behavior Questionnaire. The scale was applied to 462 students newly admitted at the Universitat de València in the 2006-2007 school year. The analyses performed made it possible to reproduce the factorial structure of the original version of the questionnaire with slight modifications in the ascription of various items. The underlying factorial structure includes four interrelated dimensions (Establishing objectives and priorities, Time management tools, Perception of time control and Preference for disorganization), which present satisfactory levels of reliability and an adequate convergent validity with the Time management subscale of the Motivated Strategies for Learning Questionnaire. The scores on the dimensions of time management show significant levels of association with academic performance in the first year of university studies, especially highlighting the predictive capacity of the subscale dealing with the Establishment of objectives and priorities. These results show the reliability and validity of this adaptation of the scale for evaluating how the students manage their academic time, and predicting their performance in the year they initiate the degree program, thus aiding in the development of intervention proposals directed towards improving these skills.

Effects of and preference for pay for performance: an analogue analysis.

PubMed

Long, Robert D; Wilder, David A; Betz, Alison; Dutta, Ami

2012-01-01

We examined the effects of 2 payment systems on the rate of check processing and time spent on task by participants in a simulated work setting. Three participants experienced individual pay-for-performance (PFP) without base pay and pay-for-time (PFT) conditions. In the last phase, we asked participants to choose which system they preferred. For all participants, the PFP condition produced higher rates of check processing and more time spent on task than did the PFT condition, but choice of payment system varied both within and across participants.

Multigrid methods with space–time concurrency

DOE PAGES

Falgout, R. D.; Friedhoff, S.; Kolev, Tz. V.; ...

2017-10-06

Here, we consider the comparison of multigrid methods for parabolic partial differential equations that allow space–time concurrency. With current trends in computer architectures leading towards systems with more, but not faster, processors, space–time concurrency is crucial for speeding up time-integration simulations. In contrast, traditional time-integration techniques impose serious limitations on parallel performance due to the sequential nature of the time-stepping approach, allowing spatial concurrency only. This paper considers the three basic options of multigrid algorithms on space–time grids that allow parallelism in space and time: coarsening in space and time, semicoarsening in the spatial dimensions, and semicoarsening in the temporalmore » dimension. We develop parallel software and performance models to study the three methods at scales of up to 16K cores and introduce an extension of one of them for handling multistep time integration. We then discuss advantages and disadvantages of the different approaches and their benefit compared to traditional space-parallel algorithms with sequential time stepping on modern architectures.« less

Multigrid methods with space–time concurrency

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

Falgout, R. D.; Friedhoff, S.; Kolev, Tz. V.

Here, we consider the comparison of multigrid methods for parabolic partial differential equations that allow space–time concurrency. With current trends in computer architectures leading towards systems with more, but not faster, processors, space–time concurrency is crucial for speeding up time-integration simulations. In contrast, traditional time-integration techniques impose serious limitations on parallel performance due to the sequential nature of the time-stepping approach, allowing spatial concurrency only. This paper considers the three basic options of multigrid algorithms on space–time grids that allow parallelism in space and time: coarsening in space and time, semicoarsening in the spatial dimensions, and semicoarsening in the temporalmore » dimension. We develop parallel software and performance models to study the three methods at scales of up to 16K cores and introduce an extension of one of them for handling multistep time integration. We then discuss advantages and disadvantages of the different approaches and their benefit compared to traditional space-parallel algorithms with sequential time stepping on modern architectures.« less

Fast Timing for High-Rate Environments with Micromegas

NASA Astrophysics Data System (ADS)

Papaevangelou, Thomas; Desforge, Daniel; Ferrer-Ribas, Esther; Giomataris, Ioannis; Godinot, Cyprien; Diaz, Diego Gonzalez; Gustavsson, Thomas; Kebbiri, Mariam; Oliveri, Eraldo; Resnati, Filippo; Ropelewski, Leszek; Tsiledakis, Georgios; Veenhof, Rob; White, Sebastian

2018-02-01

The current state of the art in fast timing resolution for existing experiments is of the order of 100 ps on the time of arrival of both charged particles and electromagnetic showers. Current R&D on charged particle timing is approaching the level of 10 ps but is not primarily directed at sustained performance at high rates and under high radiation (as would be needed for HL-LHC pileup mitigation). We demonstrate aMicromegas based solution to reach this level of performance. The Micromegas acts as a photomultiplier coupled to a Cerenkovradiator front window, which produces sufficient UV photons to convert the ˜100 ps single-photoelectron jitter into a timing response of the order of 10-20 ps per incident charged particle. A prototype has been built in order to demonstrate this performance. The first laboratory tests with a pico-second laser have shown a time resolution of the order of 27 ps for ˜50 primary photoelectrons, using a bulk Micromegas readout.

The effect of modeled absolute timing variability and relative timing variability on observational learning.

PubMed

Grierson, Lawrence E M; Roberts, James W; Welsher, Arthur M

2017-05-01

There is much evidence to suggest that skill learning is enhanced by skill observation. Recent research on this phenomenon indicates a benefit of observing variable/erred demonstrations. In this study, we explore whether it is variability within the relative organization or absolute parameterization of a movement that facilitates skill learning through observation. To do so, participants were randomly allocated into groups that observed a model with no variability, absolute timing variability, relative timing variability, or variability in both absolute and relative timing. All participants performed a four-segment movement pattern with specific absolute and relative timing goals prior to and following the observational intervention, as well as in a 24h retention test and transfers tests that featured new relative and absolute timing goals. Absolute timing error indicated that all groups initially acquired the absolute timing, maintained their performance at 24h retention, and exhibited performance deterioration in both transfer tests. Relative timing error revealed that the observation of no variability and relative timing variability produced greater performance at the post-test, 24h retention and relative timing transfer tests, but for the no variability group, deteriorated at absolute timing transfer test. The results suggest that the learning of absolute timing following observation unfolds irrespective of model variability. However, the learning of relative timing benefits from holding the absolute features constant, while the observation of no variability partially fails in transfer. We suggest learning by observing no variability and variable/erred models unfolds via similar neural mechanisms, although the latter benefits from the additional coding of information pertaining to movements that require a correction. Copyright © 2017 Elsevier B.V. All rights reserved.

Cognitive timing: neuropsychology and anatomic basis.

PubMed

Coslett, H Branch; Shenton, Jeff; Dyer, Tamarah; Wiener, Martin

2009-02-13

We report data from 31 subjects with focal hemisphere lesions (15 left hemisphere) as well as 16 normal controls on a battery of tasks assessing the estimation, production and reproduction of time intervals ranging from 2-12 s. Both visual and auditory stimuli were employed for the estimation and production tasks. First, ANOVAs were performed to assess the effect of stimulus modality on estimation and production tasks; a significant effect of stimulus modality was observed for the production but not the estimation task. Second, accuracy was significantly different for the 2 s interval as compared to longer intervals. Subsequent analyses of the data from 4-12 s stimuli demonstrated that patients with brain lesions were more variable than controls on the estimation and reproduction tasks. Additionally, patients with brain lesions but not controls exhibited significant differences in performance on the different tasks; patients with brain lesions under-produced but over-estimated time intervals of 4-12 s but performed relatively well on the reproduction task, a pattern of performance consistent with a "fast clock". There was a significant correlation between impaired performance and lesions of the parietal lobe but there was no effect of laterality of lesion or correlation between lateral frontal lobe lesions and impairment on any task.

No Clear Association between Impaired Short-Term or Working Memory Storage and Time Reproduction Capacity in Adult ADHD Patients.

PubMed

Mette, Christian; Grabemann, Marco; Zimmermann, Marco; Strunz, Laura; Scherbaum, Norbert; Wiltfang, Jens; Kis, Bernhard

2015-01-01

Altered time reproduction is exhibited by patients with adult attention deficit hyperactivity disorder (ADHD). It remains unclear whether memory capacity influences the ability of adults with ADHD to reproduce time intervals. We conducted a behavioral study on 30 ADHD patients who were medicated with methylphenidate, 29 unmedicated adult ADHD patients and 32 healthy controls (HCs). We assessed time reproduction using six time intervals (1 s, 4 s, 6 s, 10 s, 24 s and 60 s) and assessed memory performance using the Wechsler memory scale. The patients with ADHD exhibited lower memory performance scores than the HCs. No significant differences in the raw scores for any of the time intervals (p > .05), with the exception of the variability at the short time intervals (1 s, 4 s and 6 s) (p < .01), were found between the groups. The overall analyses failed to reveal any significant correlations between time reproduction at any of the time intervals examined in the time reproduction task and working memory performance (p > .05). We detected no findings indicating that working memory might influence time reproduction in adult patients with ADHD. Therefore, further studies concerning time reproduction and memory capacity among adult patients with ADHD must be performed to verify and replicate the present findings.

Association between television, movie, and video game exposure and school performance.

PubMed

Sharif, Iman; Sargent, James D

2006-10-01

The relationship between media exposure and school performance has not been studied extensively in adolescents. The purpose of this work was to test the relative effects of television, movie, and video game screen time and content on adolescent school performance. We conducted a population-based cross-sectional survey of middle school students (grades 5-8) in the Northeastern United States. We looked at weekday television and video game screen time, weekend television and video game screen time, cable movie channel availability, parental R-rated movie restriction, and television content restriction. The main outcome was self-report of school performance (excellent, good, average, or below average). We used ordinal logistic-regression analysis to test the independent effects of each variable, adjusting for demographics, child personality, and parenting style. There were 4508 students who participated in the study; gender was equally represented, and 95% were white. In multivariate analyses, after adjusting for other covariates, the odds of poorer school performance increased with increasing weekday television screen time and cable movie channel availability and decreased with parental restriction of television content restriction. As compared with children whose parents never allowed them to watch R-rated movies, children who watched R-rated movies once in a while, sometimes, or all of the time had significantly increased cumulative odds of poorer school performance. Weekend screen time and video game use were not associated with school performance. We found that both content exposure and screen time had independent detrimental associations with school performance. These findings support parental enforcement of American Academy of Pediatrics guidelines for media time (particularly weekdays) and content limits to enhance school success.

Latency study of the High Performance Time to Digital Converter for the ATLAS Muon Spectrometer trigger upgrade

NASA Astrophysics Data System (ADS)

Meng, X. T.; Levin, D. S.; Chapman, J. W.; Li, D. C.; Yao, Z. E.; Zhou, B.

2017-02-01

The High Performance Time to Digital Converter (HPTDC), a multi-channel ASIC designed by the CERN Microelectronics group, has been proposed for the digitization of the thin-Resistive Plate Chambers (tRPC) in the ATLAS Muon Spectrometer Phase-1 upgrade project. These chambers, to be staged for higher luminosity LHC operation, will increase trigger acceptance and reduce or eliminate the fake muon trigger rates in the barrel-endcap transition region, corresponding to pseudo-rapidity range 1<|η|<1.3. Low level trigger candidates must be flagged within a maximum latency of 1075 ns, thus imposing stringent signal processing time performance requirements on the readout system in general, and on the digitization electronics in particular. This paper investigates the HPTDC signal latency performance based on a specially designed evaluation board coupled with an external FPGA evaluation board, when operated in triggerless mode, and under hit rate conditions expected in Phase-I. This hardware based study confirms previous simulations and demonstrates that the HPTDC in triggerless operation satisfies the digitization timing requirements in both leading edge and pair modes.

Acceleration of high-pressure-ratio single-spool turbojet engine as determined from component performance characteristics I : effect of air bleed at compressor outlet

NASA Technical Reports Server (NTRS)

Rebeske, John J , Jr; Rohlik, Harold E

1953-01-01

An analytical investigation was made to determine from component performance characteristics the effect of air bleed at the compressor outlet on the acceleration characteristics of a typical high-pressure-ratio single-spool turbojet engine. Consideration of several operating lines on the compressor performance map with two turbine-inlet temperatures showed that for a minimum acceleration time the turbine-inlet temperature should be the maximum allowable, and the operating line on the compressor map should be as close to the surge region as possible throughout the speed range. Operation along such a line would require a continuously varying bleed area. A relatively simple two-step area bleed gives only a small increase in acceleration time over a corresponding variable-area bleed. For the modes of operation considered, over 84 percent of the total acceleration time was required to accelerate through the low-speed range ; therefore, better low-speed compressor performance (higher pressure ratios and efficiencies) would give a significant reduction in acceleration time.

Real-time automatic registration in optical surgical navigation

NASA Astrophysics Data System (ADS)

Lin, Qinyong; Yang, Rongqian; Cai, Ken; Si, Xuan; Chen, Xiuwen; Wu, Xiaoming

2016-05-01

An image-guided surgical navigation system requires the improvement of the patient-to-image registration time to enhance the convenience of the registration procedure. A critical step in achieving this aim is performing a fully automatic patient-to-image registration. This study reports on a design of custom fiducial markers and the performance of a real-time automatic patient-to-image registration method using these markers on the basis of an optical tracking system for rigid anatomy. The custom fiducial markers are designed to be automatically localized in both patient and image spaces. An automatic localization method is performed by registering a point cloud sampled from the three dimensional (3D) pedestal model surface of a fiducial marker to each pedestal of fiducial markers searched in image space. A head phantom is constructed to estimate the performance of the real-time automatic registration method under four fiducial configurations. The head phantom experimental results demonstrate that the real-time automatic registration method is more convenient, rapid, and accurate than the manual method. The time required for each registration is approximately 0.1 s. The automatic localization method precisely localizes the fiducial markers in image space. The averaged target registration error for the four configurations is approximately 0.7 mm. The automatic registration performance is independent of the positions relative to the tracking system and the movement of the patient during the operation.

2B-Alert Web: An Open-Access Tool for Predicting the Effects of Sleep/Wake Schedules and Caffeine Consumption on Neurobehavioral Performance.

PubMed

Reifman, Jaques; Kumar, Kamal; Wesensten, Nancy J; Tountas, Nikolaos A; Balkin, Thomas J; Ramakrishnan, Sridhar

2016-12-01

Computational tools that predict the effects of daily sleep/wake amounts on neurobehavioral performance are critical components of fatigue management systems, allowing for the identification of periods during which individuals are at increased risk for performance errors. However, none of the existing computational tools is publicly available, and the commercially available tools do not account for the beneficial effects of caffeine on performance, limiting their practical utility. Here, we introduce 2B-Alert Web, an open-access tool for predicting neurobehavioral performance, which accounts for the effects of sleep/wake schedules, time of day, and caffeine consumption, while incorporating the latest scientific findings in sleep restriction, sleep extension, and recovery sleep. We combined our validated Unified Model of Performance and our validated caffeine model to form a single, integrated modeling framework instantiated as a Web-enabled tool. 2B-Alert Web allows users to input daily sleep/wake schedules and caffeine consumption (dosage and time) to obtain group-average predictions of neurobehavioral performance based on psychomotor vigilance tasks. 2B-Alert Web is accessible at: https://2b-alert-web.bhsai.org. The 2B-Alert Web tool allows users to obtain predictions for mean response time, mean reciprocal response time, and number of lapses. The graphing tool allows for simultaneous display of up to seven different sleep/wake and caffeine schedules. The schedules and corresponding predicted outputs can be saved as a Microsoft Excel file; the corresponding plots can be saved as an image file. The schedules and predictions are erased when the user logs off, thereby maintaining privacy and confidentiality. The publicly accessible 2B-Alert Web tool is available for operators, schedulers, and neurobehavioral scientists as well as the general public to determine the impact of any given sleep/wake schedule, caffeine consumption, and time of day on performance of a group of individuals. This evidence-based tool can be used as a decision aid to design effective work schedules, guide the design of future sleep restriction and caffeine studies, and increase public awareness of the effects of sleep amounts, time of day, and caffeine on alertness. © 2016 Associated Professional Sleep Societies, LLC.

The validity of ACT-PEP test scores for predicting academic performance of registered nurses in BSN programs.

PubMed

Yang, J C; Noble, J

1990-01-01

This study investigated the validity of three American College Testing-Proficiency Examination Program (ACT-PEP) tests (Maternal and Child Nursing, Psychiatric/Mental Health Nursing, Adult Nursing) for predicting the academic performance of registered nurses (RNs) enrolled in bachelor's degree BSN programs nationwide. This study also examined RN students' performance on the ACT-PEP tests by their demographic characteristics: student's age, sex, race, student status (full- or part-time), and employment status (full- or part-time). The total sample for the three tests comprised 2,600 students from eight institutions nationwide. The median correlation coefficients between the three ACT-PEP tests and the semester grade point averages ranged from .36 to .56. Median correlation coefficients increased over time, supporting the stability of ACT-PEP test scores for predicting academic performance over time. The relative importance of selected independent variables for predicting academic performance was also examined; the most important variable for predicting academic performance was typically the ACT-PEP test score. Across the institutions, student demographic characteristics did not contribute significantly to explaining academic performance, over and above ACT-PEP scores.

Why are they late? Timing abilities and executive control among students with learning disabilities.

PubMed

Grinblat, Nufar; Rosenblum, Sara

2016-12-01

While a deficient ability to perform daily tasks on time has been reported among students with learning disabilities (LD), the underlying mechanism behind their 'being late' is still unclear. This study aimed to evaluate the organization in time, time estimation abilities, actual performance time pertaining to specific daily activities, as well as the executive functions of students with LD in comparison to those of controls, and to assess the relationships between these domains among each group. The participants were 27 students with LD, aged 20-30, and 32 gender and age-matched controls who completed the Time Organization and Participation Scale (TOPS) and the Behavioral Rating Inventory of Executive Function-Adult version (BRIEF-A). In addition, their ability to estimate the time needed to complete the task of preparing a cup of coffee as well as their actual performance time were evaluated. The results indicated that in comparison to controls, students with LD showed significantly inferior organization in time (TOPS) and executive function abilities (BRIEF-A). Furthermore, their time estimation abilities were significantly inferior and they required significantly more time to prepare a cup of coffee. Regression analysis identified the variables that predicted organization in time and task performance time among each group. The significance of the results for both theoretical and clinical implications are discussed. What this paper adds? This study examines the underlying mechanism of the phenomena of being late among students with LD. Following a recent call for using ecologically valid assessments, the functional daily ability of students with LD to prepare a cup of coffee and to organize time were investigated. Furthermore, their time estimation and executive control abilities were examined as a possible underlying mechanism for their lateness. Although previous studies have indicated executive control deficits among students with LD, to our knowledge, this is the first analysis of the relationships between their executive control and time estimation deficits and their influence upon their daily function and organization in time abilities. Our findings demonstrate that students with LD need more time in order to execute simple daily activities, such as preparing a cup of coffee. Deficient working memory, retrospective time estimation ability and inhibition predicted their performance time and organization in time abilities. Therefore, this paper sheds light on the mechanism behind daily performance in time among students with LD and emphasizes the need for future development of focused intervention programs to meet their unique needs. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Performance of Noncoherent Orthogonal M-FSK in the Presence of Timing and Frequency Errors

NASA Technical Reports Server (NTRS)

Hinedi, Sami; Simon, Marvin K.; Raphaeli, Dan

1993-01-01

Practical M-FSK systems experience a combination of time and frequency offsets (errors). This paper assesses the deleterious effect of these offsets, first individually and then combined, on the average bit error probability performance of the system.

Seven Q-Tracks monitors of laboratory quality drive general performance improvement: experience from the College of American Pathologists Q-Tracks program 1999-2011.

PubMed

Meier, Frederick A; Souers, Rhona J; Howanitz, Peter J; Tworek, Joseph A; Perrotta, Peter L; Nakhleh, Raouf E; Karcher, Donald S; Bashleben, Christine; Darcy, Teresa P; Schifman, Ron B; Jones, Bruce A

2015-06-01

Many production systems employ standardized statistical monitors that measure defect rates and cycle times, as indices of performance quality. Clinical laboratory testing, a system that produces test results, is amenable to such monitoring. To demonstrate patterns in clinical laboratory testing defect rates and cycle time using 7 College of American Pathologists Q-Tracks program monitors. Subscribers measured monthly rates of outpatient order-entry errors, identification band defects, and specimen rejections; median troponin order-to-report cycle times and rates of STAT test receipt-to-report turnaround time outliers; and critical values reporting event defects, and corrected reports. From these submissions Q-Tracks program staff produced quarterly and annual reports. These charted each subscriber's performance relative to other participating laboratories and aggregate and subgroup performance over time, dividing participants into best and median performers and performers with the most room to improve. Each monitor's patterns of change present percentile distributions of subscribers' performance in relation to monitoring durations and numbers of participating subscribers. Changes over time in defect frequencies and the cycle duration quantify effects on performance of monitor participation. All monitors showed significant decreases in defect rates as the 7 monitors ran variously for 6, 6, 7, 11, 12, 13, and 13 years. The most striking decreases occurred among performers who initially had the most room to improve and among subscribers who participated the longest. All 7 monitors registered significant improvement. Participation effects improved between 0.85% and 5.1% per quarter of participation. Using statistical quality measures, collecting data monthly, and receiving reports quarterly and yearly, subscribers to a comparative monitoring program documented significant decreases in defect rates and shortening of a cycle time for 6 to 13 years in all 7 ongoing clinical laboratory quality monitors.

Cerebral Small Vessel Disease Burden Is Associated with Motor Performance of Lower and Upper Extremities in Community-Dwelling Populations

PubMed Central

Su, Ning; Zhai, Fei-Fei; Zhou, Li-Xin; Ni, Jun; Yao, Ming; Li, Ming-Li; Jin, Zheng-Yu; Gong, Gao-Lang; Zhang, Shu-Yang; Cui, Li-Ying; Tian, Feng; Zhu, Yi-Cheng

2017-01-01

Objective: To investigate the correlation between cerebral small vessel disease (CSVD) burden and motor performance of lower and upper extremities in community-dwelling populations. Methods: We performed a cross-sectional analysis on 770 participants enrolled in the Shunyi study, which is a population-based cohort study. CSVD burden, including white matter hyperintensities (WMH), lacunes, cerebral microbleeds (CMBs), perivascular spaces (PVS), and brain atrophy were measured using 3T magnetic resonance imaging. All participants underwent quantitative motor assessment of lower and upper extremities, which included 3-m walking speed, 5-repeat chair-stand time, 10-repeat pronation–supination time, and 10-repeat finger-tapping time. Data on demographic characteristics, vascular risk factors, and cognitive functions were collected. General linear model analysis was performed to identify potential correlations between motor performance measures and imaging markers of CSVD after controlling for confounding factors. Results: For motor performance of the lower extremities, WMH was negatively associated with gait speed (standardized β = -0.092, p = 0.022) and positively associated with chair-stand time (standardized β = 0.153, p < 0.0001, surviving FDR correction). For motor performance of the upper extremities, pronation–supination time was positively associated with WMH (standardized β = 0.155, p < 0.0001, surviving FDR correction) and negatively with brain parenchymal fraction (BPF; standardized β = -0.125, p = 0.011, surviving FDR correction). Only BPF was found to be negatively associated with finger-tapping time (standardized β = -0.123, p = 0.012). However, lacunes, CMBs, or PVS were not found to be associated with motor performance of lower or upper extremities in multivariable analysis. Conclusion: Our findings suggest that cerebral microstructural changes related to CSVD may affect motor performance of both lower and upper extremities. WMH and brain atrophy are most strongly associated with motor function deterioration in community-dwelling populations. PMID:29021757

Cerebral Small Vessel Disease Burden Is Associated with Motor Performance of Lower and Upper Extremities in Community-Dwelling Populations.

PubMed

Su, Ning; Zhai, Fei-Fei; Zhou, Li-Xin; Ni, Jun; Yao, Ming; Li, Ming-Li; Jin, Zheng-Yu; Gong, Gao-Lang; Zhang, Shu-Yang; Cui, Li-Ying; Tian, Feng; Zhu, Yi-Cheng

2017-01-01

Objective: To investigate the correlation between cerebral small vessel disease (CSVD) burden and motor performance of lower and upper extremities in community-dwelling populations. Methods: We performed a cross-sectional analysis on 770 participants enrolled in the Shunyi study, which is a population-based cohort study. CSVD burden, including white matter hyperintensities (WMH), lacunes, cerebral microbleeds (CMBs), perivascular spaces (PVS), and brain atrophy were measured using 3T magnetic resonance imaging. All participants underwent quantitative motor assessment of lower and upper extremities, which included 3-m walking speed, 5-repeat chair-stand time, 10-repeat pronation-supination time, and 10-repeat finger-tapping time. Data on demographic characteristics, vascular risk factors, and cognitive functions were collected. General linear model analysis was performed to identify potential correlations between motor performance measures and imaging markers of CSVD after controlling for confounding factors. Results: For motor performance of the lower extremities, WMH was negatively associated with gait speed (standardized β = -0.092, p = 0.022) and positively associated with chair-stand time (standardized β = 0.153, p < 0.0001, surviving FDR correction). For motor performance of the upper extremities, pronation-supination time was positively associated with WMH (standardized β = 0.155, p < 0.0001, surviving FDR correction) and negatively with brain parenchymal fraction (BPF; standardized β = -0.125, p = 0.011, surviving FDR correction). Only BPF was found to be negatively associated with finger-tapping time (standardized β = -0.123, p = 0.012). However, lacunes, CMBs, or PVS were not found to be associated with motor performance of lower or upper extremities in multivariable analysis. Conclusion: Our findings suggest that cerebral microstructural changes related to CSVD may affect motor performance of both lower and upper extremities. WMH and brain atrophy are most strongly associated with motor function deterioration in community-dwelling populations.

Tracking performance under time sharing conditions with a digit processing task: A feedback control theory analysis. [attention sharing effect on operator performance

NASA Technical Reports Server (NTRS)

Gopher, D.; Wickens, C. D.

1975-01-01

A one dimensional compensatory tracking task and a digit processing reaction time task were combined in a three phase experiment designed to investigate tracking performance in time sharing. Adaptive techniques, elaborate feedback devices, and on line standardization procedures were used to adjust task difficulty to the ability of each individual subject and manipulate time sharing demands. Feedback control analysis techniques were employed in the description of tracking performance. The experimental results show that when the dynamics of a system are constrained, in such a manner that man machine system stability is no longer a major concern of the operator, he tends to adopt a first order control describing function, even with tracking systems of higher order. Attention diversion to a concurrent task leads to an increase in remnant level, or nonlinear power. This decrease in linearity is reflected both in the output magnitude spectra of the subjects, and in the linear fit of the amplitude ratio functions.

The effect of music on 10-km cycle time-trial performance.

PubMed

Hagen, Jana; Foster, Carl; Rodríguez-Marroyo, Jose; de Koning, Jos J; Mikat, Richard P; Hendrix, Charles R; Porcari, John P

2013-01-01

Music is widely used as an ergogenic aid in sport, but there is little evidence of its effectiveness during closed-loop athletic events. In order to determine the effectiveness of music as an ergogenic aid, well-trained and task-habituated cyclists performed 10-km cycle time trials either while listening to self-selected motivational music or with auditory input blocked. There were no statistically significant differences in performance time or physiological or psychological markers related to music (time-trial duration17.75 ± 2.10 vs 17.81 ± 2.06 min, mean power output 222 ± 66 vs 220 ± 65 W, peak heart rate184 ± 9 vs 183 ± 8 beats/min, peak blood lactate12.1 ± 2.6 vs 11.9 ± 2.1 mmol/L, and final rating of perceived exertion 8.4 ± 1.5 vs 8.5 ± 1.6). It is concluded that during exercise at competitive intensity, there is no meaningful effect of music on either performance or physiology.

Association Between Extraversion and Exercise Performance Among Elderly Persons Receiving a Videogame Intervention.

PubMed

Zaitsu, Kosuke; Nishimura, Yuki; Matsuguma, Hiroyuki; Higuchi, Shigekazu

2015-10-01

We examined the effects of an exergame intervention on exercise performance, as well as the influence of players' personality traits on the effects of the intervention. In total, 16 elderly persons (>65 years old) participated in the study for 12 weeks. Participants were required to complete the Big Five Scale. We measured the number of times that the sit-to-stand exercise was performed during the interventions with and without exergames. We compared the average number of times that the sit-to-stand exercise was performed per day in each of the two conditions. The average number of times that exercise was undertaken with exergame use was greater than that without exergame use; however, no significant difference was found. The difference between the average number of times that exercise occurred with and without exergame use was positively correlated with neuroticism, negatively correlated with extraversion, and not associated with conscientiousness. The intervention comprising the use of exergames has a positive motivational influence among less extraverted elderly persons.

Evaluation of bus transit reliability in the District of Columbia.

DOT National Transportation Integrated Search

2013-11-01

Several performance metrics can be used to assess the reliability of a transit system. These include on-time arrivals, travel-time : adherence, run-time adherence, and customer satisfaction, among others. On-time arrival at bus stops is one of the pe...

A perturbative approach for enhancing the performance of time series forecasting.

PubMed

de Mattos Neto, Paulo S G; Ferreira, Tiago A E; Lima, Aranildo R; Vasconcelos, Germano C; Cavalcanti, George D C

2017-04-01

This paper proposes a method to perform time series prediction based on perturbation theory. The approach is based on continuously adjusting an initial forecasting model to asymptotically approximate a desired time series model. First, a predictive model generates an initial forecasting for a time series. Second, a residual time series is calculated as the difference between the original time series and the initial forecasting. If that residual series is not white noise, then it can be used to improve the accuracy of the initial model and a new predictive model is adjusted using residual series. The whole process is repeated until convergence or the residual series becomes white noise. The output of the method is then given by summing up the outputs of all trained predictive models in a perturbative sense. To test the method, an experimental investigation was conducted on six real world time series. A comparison was made with six other methods experimented and ten other results found in the literature. Results show that not only the performance of the initial model is significantly improved but also the proposed method outperforms the other results previously published. Copyright © 2017 Elsevier Ltd. All rights reserved.

Long Term Performance Metrics of the GD SDR on the SCaN Testbed: The First Year on the ISS

NASA Technical Reports Server (NTRS)

Nappier, Jennifer; Wilson, Molly C.

2014-01-01

The General Dynamics (GD) S-Band software defined radio (SDR) in the Space Communications and Navigation (SCaN) Testbed on the International Space Station (ISS) provides experimenters an opportunity to develop and demonstrate experimental waveforms in space. The SCaN Testbed was installed on the ISS in August of 2012. After installation, the initial checkout and commissioning phases were completed and experimental operations commenced. One goal of the SCaN Testbed is to collect long term performance metrics for SDRs operating in space in order to demonstrate long term reliability. These metrics include the time the SDR powered on, the time the power amplifier (PA) is powered on, temperature trends, error detection and correction (EDAC) behavior, and waveform operational usage time. This paper describes the performance of the GD SDR over the first year of operations on the ISS.

Pre-task music improves swimming performance.

PubMed

Smirmaul, B P; Dos Santos, R V; Da Silva Neto, L V

2015-12-01

The purpose of this study was to investigate the effects of pre-task music on swimming performance and other psychological variables. A randomized counterbalanced within-subjects (experimental and control condition) design was employed. Eighteen regional level male swimmers performed two 200-m freestyle swimming time trials. Participants were exposed to either 5 minutes of self-selected music (pre-task music condition) or 5 minutes of silence (control condition) and, after 1 minute, performed the swimming task. Swimming time was significantly shorter (-1.44%) in the pre-task music condition. Listening to pre-task music increased motivation to perform the swimming task, while arousal remained unchanged. While fatigue increased after the swimming task in both conditions, vigor, ratings of perceived exertion and affective valence were unaltered. It is concluded, for the first time, that pre-task music improves swimming performance.

5nsec Dead time multichannel scaling system for Mössbauer spectrometer

NASA Astrophysics Data System (ADS)

Verrastro, C.; Trombetta, G.; Pita, A.; Saragovi, C.; Duhalde, S.

1991-11-01

A PC programmable and fast multichannel scaling module has been designed to use a commercial Mössbauer spectrometer. This module is based on a 10 single chip 8 bits microcomputer (MC6805) and on a 35 fast ALU, which allows a high performance and low cost system. The module can operate in a stand-alone mode. Data analysis are performed in real time display, on XT/AT IBM PC or compatibles. The channels are ranged between 256 and 4096, the maximum number of counts is 232-1 per channel, the dwell time is 3 μsec and the dead time between channels is 5 nsec. A friendly software display the real time spectrum and offers menues with different options at each state.

No evidence of reaction time slowing in autism spectrum disorder.

PubMed

Ferraro, F Richard

2016-01-01

A total of 32 studies comprising 238 simple reaction time and choice reaction time conditions were examined in individuals with autism spectrum disorder (n = 964) and controls (n = 1032). A Brinley plot/multiple regression analysis was performed on mean reaction times, regressing autism spectrum disorder performance onto the control performance as a way to examine any generalized simple reaction time/choice reaction time slowing exhibited by the autism spectrum disorder group. The resulting regression equation was Y (autism spectrum disorder) = 0.99 × (control) + 87.93, which accounted for 92.3% of the variance. These results suggest that there are little if any simple reaction time/choice reaction time slowing in this sample of individual with autism spectrum disorder, in comparison with controls. While many cognitive and information processing domains are compromised in autism spectrum disorder, it appears that simple reaction time/choice reaction time remain relatively unaffected in autism spectrum disorder. © The Author(s) 2014.

Choosing colors for map display icons using models of visual search.

PubMed

Shive, Joshua; Francis, Gregory

2013-04-01

We show how to choose colors for icons on maps to minimize search time using predictions of a model of visual search. The model analyzes digital images of a search target (an icon on a map) and a search display (the map containing the icon) and predicts search time as a function of target-distractor color distinctiveness and target eccentricity. We parameterized the model using data from a visual search task and performed a series of optimization tasks to test the model's ability to choose colors for icons to minimize search time across icons. Map display designs made by this procedure were tested experimentally. In a follow-up experiment, we examined the model's flexibility to assign colors in novel search situations. The model fits human performance, performs well on the optimization tasks, and can choose colors for icons on maps with novel stimuli to minimize search time without requiring additional model parameter fitting. Models of visual search can suggest color choices that produce search time reductions for display icons. Designers should consider constructing visual search models as a low-cost method of evaluating color assignments.

Neuromuscular and athletic performance following core strength training in elite youth soccer: Role of instability.

PubMed

Prieske, O; Muehlbauer, T; Borde, R; Gube, M; Bruhn, S; Behm, D G; Granacher, U

2016-01-01

Cross-sectional studies revealed that inclusion of unstable elements in core-strengthening exercises produced increases in trunk muscle activity and thus potential extra stimuli to induce more pronounced performance enhancements in youth athletes. Thus, the purpose of the study was to investigate changes in neuromuscular and athletic performance following core strength training performed on unstable (CSTU) compared with stable surfaces (CSTS) in youth soccer players. Thirty-nine male elite soccer players (age: 17 ± 1 years) were assigned to two groups performing a progressive core strength-training program for 9 weeks (2-3 times/week) in addition to regular in-season soccer training. CSTS group conducted core exercises on stable (i.e., floor, bench) and CSTU group on unstable (e.g., Thera-Band® Stability Trainer, Togu© Swiss ball) surfaces. Measurements included tests for assessing trunk muscle strength/activation, countermovement jump height, sprint time, agility time, and kicking performance. Statistical analysis revealed significant main effects of test (pre vs post) for trunk extensor strength (5%, P < 0.05, d = 0.86), 10-20-m sprint time (3%, P < 0.05, d = 2.56), and kicking performance (1%, P < 0.01, d = 1.28). No significant Group × test interactions were observed for any variable. In conclusion, trunk muscle strength, sprint, and kicking performance improved following CSTU and CSTS when conducted in combination with regular soccer training. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Grayscale image segmentation for real-time traffic sign recognition: the hardware point of view

NASA Astrophysics Data System (ADS)

Cao, Tam P.; Deng, Guang; Elton, Darrell

2009-02-01

In this paper, we study several grayscale-based image segmentation methods for real-time road sign recognition applications on an FPGA hardware platform. The performance of different image segmentation algorithms in different lighting conditions are initially compared using PC simulation. Based on these results and analysis, suitable algorithms are implemented and tested on a real-time FPGA speed sign detection system. Experimental results show that the system using segmented images uses significantly less hardware resources on an FPGA while maintaining comparable system's performance. The system is capable of processing 60 live video frames per second.

Active eye fixation performance in 940 young men: effects of IQ, schizotypy, anxiety and depression.

PubMed

Smyrnis, N; Kattoulas, E; Evdokimidis, I; Stefanis, N C; Avramopoulos, D; Pantes, G; Theleritis, C; Stefanis, C N

2004-05-01

A total of 940 young men performed a task in which they actively maintained fixation for 50 s in three conditions: a). on a visual target, b). on a visual target while distracting targets appeared briefly on the periphery and c). with no visual target present. The same individuals completed psychometric evaluation tests measuring IQ, schizotypy and current state-dependent psychopathology. The proportion of fixation time decreased and saccade frequency increased in condition b compared wih condition a, and sequentially in condition c compared with condition b. A trend towards a decrease in proportion of fixation time and increase in saccade frequency was found as the subjects maintained fixation during the task and this time-dependent deterioration of performance was again most pronounced in condition c, less so in condition b and absent in condition a. Psychometric test scores were significantly correlated with fixation performance in the population. Worse performance in all three fixation conditions was observed for individuals with lower IQ scores. A deterioration of fixation performance with time in condition b was correlated with disorganization characteristics of schizotypy, suggesting that these individuals had difficulty maintaining active fixation in the presence of increased inhibitory load. A connection of such a difficulty with the frontal lobes and their role in the control of voluntary inhibitory functions is discussed.

Airplane takeoff and landing performance monitoring system

NASA Technical Reports Server (NTRS)

Middleton, David B. (Inventor); Srivatsan, Raghavachari (Inventor); Person, Jr., Lee H. (Inventor)

1991-01-01

The invention is a real-time takeoff and landing performance monitoring system for an aircraft which provides a pilot with graphic and metric information to assist in decisions related to achieving rotation speed (V.sub.R) within the safe zone of a runway, or stopping the aircraft on the runway after landing or take-off abort. The system processes information in two segments: a pretakeoff segment and a real-time segment. One-time inputs of ambient conditions and airplane configuration information are used in the pretakeoff segment to generate scheduled performance data. The real-time segment uses the scheduled performance data, runway length data and transducer measured parameters to monitor the performance of the airplane throughout the takeoff roll. Airplane and engine performance deficiencies are detected and annunciated. A novel and important feature of this segment is that it updates the estimated runway rolling friction coefficient. Airplane performance predictions also reflect changes in head wind occurring as the takeoff roll progresses. The system provides a head-down display and a head-up display. The head-up display is projected onto a partially reflective transparent surface through which the pilot views the runway. By comparing the present performance of the airplane with a predicted nominal performance based upon given conditions, performance deficiencies are detected by the system.

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

NASA Astrophysics Data System (ADS)

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

2016-11-01

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

Physiological and performance effects of carbohydrate gels consumed prior to the extra-time period of prolonged simulated soccer match-play.

PubMed

Harper, Liam D; Briggs, Marc A; McNamee, Ged; West, Daniel J; Kilduff, Liam P; Stevenson, Emma; Russell, Mark

2016-06-01

The physiological and performance effects of carbohydrate-electrolyte gels consumed before the 30min extra-time period of prolonged soccer-specific exercise were investigated. Randomised, double-blind, crossover. Eight English Premier League academy soccer players performed 120min of soccer-specific exercise on two occasions while consuming fluid-electrolyte beverages before exercise, at half-time and 90min. Carbohydrate-electrolyte (0.7±0.1gkg(-1) BM) or energy-free placebo gels were consumed ∼5min before extra-time. Blood samples were taken before exercise, at half-time and every 15min during exercise. Physical (15-m and 30-m sprint speed, 30-m sprint maintenance and countermovement jump height) and technical (soccer dribbling) performance was assessed throughout each trial. Carbohydrate-electrolyte gels improved dribbling precision (+29±20%) and raised blood glucose concentrations by 0.7±0.8mmoll(-1) during extra-time (both p<0.01). Supplementation did not affect sprint velocities (15m and 30m), 30-m sprint maintenance or dribbling speed as reductions compared to 0-15min values occurred at 105-120min irrespective of trial (all p<0.05). Plasma osmolality and blood sodium concentrations increased post-exercise vs. the opening 15min (p<0.05) but no effect of supplementation existed. Selected markers of physical performance (jump height, 30-m sprint velocity and 30-m repeated sprint maintenance) also reduced by >3% during half-time (all p<0.05). Carbohydrate-electrolyte gel ingestion raised blood glucose concentrations and improved dribbling performance during the extra-time period of simulated soccer match-play. Supplementation did not attenuate reductions in physical performance and hydration status that occurred during extra-time. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Time perception impairment in early-to-moderate stages of Huntington's disease is related to memory deficits.

PubMed

Righi, Stefania; Galli, Luca; Paganini, Marco; Bertini, Elisabetta; Viggiano, Maria Pia; Piacentini, Silvia

2016-01-01

Huntington's disease (HD) primarily affects striatum and prefrontal dopaminergic circuits which are fundamental neural correlates of the timekeeping mechanism. The few studies on HD mainly investigated motor timing performance in second durations. The present work explored time perception in early-to-moderate symptomatic HD patients for seconds and milliseconds with the aim to clarify which component of the scalar expectancy theory (SET) is mainly responsible for HD timing defect. Eleven HD patients were compared to 11 controls employing two separate temporal bisection tasks in second and millisecond ranges. Our results revealed the same time perception deficits for seconds and milliseconds in HD patients. Time perception impairment in early-to-moderate stages of Huntington's disease is related to memory deficits. Furthermore, both the non-systematical defect of temporal sensitivity and the main impairment of timing performance in the extreme value of the psychophysical curves suggested an HD deficit in the memory component of the SET. This result was further confirmed by the significant correlations between time perception performance and long-term memory test scores. Our findings added important preliminary data for both a deeper comprehension of HD time-keeping deficits and possible implications on neuro-rehabilitation practices.

Evaluating stereoscopic displays: both efficiency measures and perceived workload sensitive to manipulations in binocular disparity

NASA Astrophysics Data System (ADS)

van Beurden, Maurice H. P. H.; Ijsselsteijn, Wijnand A.; de Kort, Yvonne A. W.

2011-03-01

Stereoscopic displays are known to offer a number of key advantages in visualizing complex 3D structures or datasets. The large majority of studies that focus on evaluating stereoscopic displays for professional applications use completion time and/or the percentage of correct answers to measure potential performance advantages. However, completion time and accuracy may not fully reflect all the benefits of stereoscopic displays. In this paper, we argue that perceived workload is an additional valuable indicator reflecting the extent to which users can benefit from using stereoscopic displays. We performed an experiment in which participants were asked to perform a visual path-tracing task within a convoluted 3D wireframe structure, varying in level of complexity of the visualised structure and level of disparity of the visualisation. The results showed that an optimal performance (completion time, accuracy and workload), depend both on task difficulty and disparity level. Stereoscopic disparity revealed a faster and more accurate task performance, whereas we observed a trend that performance on difficult tasks stands to benefit more from higher levels of disparity than performance on easy tasks. Perceived workload (as measured using the NASA-TLX) showed a similar response pattern, providing evidence that perceived workload is sensitive to variations in disparity as well as task difficulty. This suggests that perceived workload could be a useful concept, in addition to standard performance indicators, in characterising and measuring human performance advantages when using stereoscopic displays.

Database Performance Monitoring for the Photovoltaic Systems

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

Klise, Katherine A.

The Database Performance Monitoring (DPM) software (copyright in processes) is being developed at Sandia National Laboratories to perform quality control analysis on time series data. The software loads time indexed databases (currently csv format), performs a series of quality control tests defined by the user, and creates reports which include summary statistics, tables, and graphics. DPM can be setup to run on an automated schedule defined by the user. For example, the software can be run once per day to analyze data collected on the previous day. HTML formatted reports can be sent via email or hosted on a website.more » To compare performance of several databases, summary statistics and graphics can be gathered in a dashboard view which links to detailed reporting information for each database. The software can be customized for specific applications.« less

Methylphenidate, modafinil, and caffeine for cognitive enhancement in chess: A double-blind, randomised controlled trial.

PubMed

Franke, Andreas G; Gränsmark, Patrik; Agricola, Alexandra; Schühle, Kai; Rommel, Thilo; Sebastian, Alexandra; Balló, Harald E; Gorbulev, Stanislav; Gerdes, Christer; Frank, Björn; Ruckes, Christian; Tüscher, Oliver; Lieb, Klaus

2017-03-01

Stimulants and caffeine have been proposed for cognitive enhancement by healthy subjects. This study investigated whether performance in chess - a competitive mind game requiring highly complex cognitive skills - can be enhanced by methylphenidate, modafinil or caffeine. In a phase IV, randomized, double-blind, placebo-controlled trial, 39 male chess players received 2×200mg modafinil, 2×20mg methylphenidate, and 2×200mg caffeine or placebo in a 4×4 crossover design. They played twenty 15-minute games during two sessions against a chess program (Fritz 12; adapted to players' strength) and completed several neuropsychological tests. Marked substance effects were observed since all three substances significantly increased average reflection time per game compared to placebo resulting in a significantly increased number of games lost on time with all three treatments. Treatment effects on chess performance were not seen if all games (n=3059) were analysed. Only when controlling for game duration as well as when excluding those games lost on time, both modafinil and methylphenidate enhanced chess performance as demonstrated by significantly higher scores in the remaining 2876 games compared to placebo. In conjunction with results from neuropsychological testing we conclude that modifying effects of stimulants on complex cognitive tasks may in particular result from more reflective decision making processes. When not under time pressure, such effects may result in enhanced performance. Yet, under time constraints more reflective decision making may not improve or even have detrimental effects on complex task performance. Copyright © 2017 Elsevier B.V. and ECNP. All rights reserved.

Physical performance measurement in persons with patellofemoral osteoarthritis: A pilot study.

PubMed

Hoglund, Lisa T; Lockard, Margery A; Barbe, Mary F; Hillstrom, Howard J; Song, Jinsup; Reinus, William R; Barr-Gillespie, Ann E

2015-01-01

Patellofemoral osteoarthritis (PFOA) is associated with pain and decreased self-reported function. The impact of PFOA on actual physical performance is currently unknown. To investigate the impact of PFOA on physical performance and pain. Eight participants aged 40-65 years with bilateral, symptomatic, radiographic PFOA and 7 age- and gender-matched pain-free control participants without radiographic PFOA were studied. Physical performance was measured with the Timed-Up-and-Go (TUG) and 50-foot Fast-Paced-Walk (FPW) tests. Dependent variables included time to complete the TUG and FPW; pretest-posttest change in pain intensity (TUG and FPW); and self-reports of perceived knee pain, stiffness, and physical function. Data were analyzed with nonparametric statistics. The PFOA group TUG time was longer than the control group (p=0.01). No difference between groups was found for FPW time. Pretest-posttest pain increased for the TUG and FPW in PFOA participants (p< 0.05). The PFOA group reported greater knee pain, stiffness, and less physical function than controls (previous 48 hours) (p < 0.01). Symptomatic, radiographic PFOA is associated with increased pain during the TUG and FPW tests and longer time required to complete the TUG. The TUG may be a more sensitive test of physical performance in PFOA.

Development, construct validity and test-retest reliability of a field-based wheelchair mobility performance test for wheelchair basketball.

PubMed

de Witte, Annemarie M H; Hoozemans, Marco J M; Berger, Monique A M; van der Slikke, Rienk M A; van der Woude, Lucas H V; Veeger, Dirkjan H E J

2018-01-01

The aim of this study was to develop and describe a wheelchair mobility performance test in wheelchair basketball and to assess its construct validity and reliability. To mimic mobility performance of wheelchair basketball matches in a standardised manner, a test was designed based on observation of wheelchair basketball matches and expert judgement. Forty-six players performed the test to determine its validity and 23 players performed the test twice for reliability. Independent-samples t-tests were used to assess whether the times needed to complete the test were different for classifications, playing standards and sex. Intraclass correlation coefficients (ICC) were calculated to quantify reliability of performance times. Males performed better than females (P < 0.001, effect size [ES] = -1.26) and international men performed better than national men (P < 0.001, ES = -1.62). Performance time of low (≤2.5) and high (≥3.0) classification players was borderline not significant with a moderate ES (P = 0.06, ES = 0.58). The reliability was excellent for overall performance time (ICC = 0.95). These results show that the test can be used as a standardised mobility performance test to validly and reliably assess the capacity in mobility performance of elite wheelchair basketball athletes. Furthermore, the described methodology of development is recommended for use in other sports to develop sport-specific tests.

Microsurgical Performance After Sleep Interruption: A NeuroTouch Simulator Study.

PubMed

Micko, Alexander; Knopp, Karoline; Knosp, Engelbert; Wolfsberger, Stefan

2017-10-01

In times of the ubiquitous debate about doctors' working hour restrictions, it is still questionable if the physician's performance is impaired by high work load and long shifts. In this study, we evaluated the impact of sleep interruption on neurosurgical performance. Ten medical students and 10 neurosurgical residents were tested on the virtual-reality simulator NeuroTouch by performing an identical microsurgical task, well rested (baseline test), and after sleep interruption at night (stress test). Deviation of total score, timing, and excessive force on tissue were evaluated. In addition, vital parameters and self-assessment were analyzed. After sleep interruption, total performance score increased significantly (45.1 vs. 48.7, baseline vs. stress test, P = 0.048) while timing remained stable (10.1 vs. 10.4 minutes for baseline vs. stress test, P > 0.05) for both students and residents. Excessive force decreased in both groups during the stress test for the nondominant hand (P = 0.05). For the dominant hand, an increase of excessive force was encountered in the group of residents (P = 0.05). In contrast to their results, participants of both groups assessed their performance worse during the stress test. In our study, we found an increase of neurosurgical simulator performance in neurosurgical residents and medical students under simulated night shift conditions. Further, microsurgical dexterity remained unchanged. Based on our results and the data in the available literature, we cannot confirm that working hour restrictions will have a positive effect on neurosurgical performance. Copyright © 2017 Elsevier Inc. All rights reserved.

Computerized Maze Navigation and On-Road Performance by Drivers With Dementia

PubMed Central

Ott, Brian R.; Festa, Elena K.; Amick, Melissa M.; Grace, Janet; Davis, Jennifer D.; Heindel, William C.

2012-01-01

This study examined the ability of computerized maze test performance to predict the road test performance of cognitively impaired and normal older drivers. The authors examined 133 older drivers, including 65 with probable Alzheimer disease, 23 with possible Alzheimer disease, and 45 control subjects without cognitive impairment. Subjects completed 5 computerized maze tasks employing a touch screen and pointer as well as a battery of standard neuropsychological tests. Parameters measured for mazes included errors, planning time, drawing time, and total time. Within 2 weeks, subjects were examined by a professional driving instructor on a standardized road test modeled after the Washington University Road Test. Road test total score was significantly correlated with total time across the 5 mazes. This maze score was significant for both Alzheimer disease subjects and control subjects. One maze in particular, requiring less than 2 minutes to complete, was highly correlated with driving performance. For the standard neuropsychological tests, highest correlations were seen with Trail Making A (TrailsA) and the Hopkins Verbal Learning Tests Trial 1 (HVLT1). Multiple regression models for road test score using stepwise subtraction of maze and neuropsychological test variables revealed significant independent contributions for total maze time, HVLT1, and TrailsA for the entire group; total maze time and HVLT1 for Alzheimer disease subjects; and TrailsA for normal subjects. As a visual analog of driving, a brief computerized test of maze navigation time compares well to standard neuropsychological tests of psychomotor speed, scanning, attention, and working memory as a predictor of driving performance by persons with early Alzheimer disease and normal elders. Measurement of maze task performance appears to be useful in the assessment of older drivers at risk for hazardous driving. PMID:18287166

Exploring the Effects of Working Memory on Time Perception in Attention Deficit Hyperactivity Disorder.

PubMed

Lee, Hom-Yi; Yang, En-Lin

2018-01-01

Children with attention deficit hyperactivity disorder (ADHD) are often reported to have deficits of time perception. However, there is a strong relation between performance on tasks of working memory and time perception. Thus, it is possible that the poor performance of children with ADHD on time perception results from their deficit of working memory. In this study, the working memory of participants was separately assessed; therefore, we could explore the relationship between working memory and time perception of children with ADHD. Fifty-six children with ADHD and those of healthy controls completed tasks measuring working memory and time perception. The results showed that the time discrimination ability of children with ADHD was poorer than that of controls. However, there was a strong association between time perception and working memory. After controlling working memory and intelligence, the time discrimination ability of children with ADHD was not significantly poorer than that of controls. We suggest that there is an interdependent relationship between time perception and working memory for children with ADHD.

Relationships among Testing Medium, Test Performance, and Testing Time of High School Students Who Are Visually Impaired

ERIC Educational Resources Information Center

Erin, Jane N.; Hong, Sunggye; Schoch, Christina; Kuo, YaJu

2006-01-01

This study compared the test scores and time required by high school students who are blind, sighted, or have low vision to complete tests administered in written and oral formats. The quantitative results showed that the blind students performed better on multiple-choice tests in braille and needed more time while taking tests in braille. The…

Pacing and Performance in Competitive Middle-Distance Speed Skating

ERIC Educational Resources Information Center

Muehlbauer, Thomas; Schindler, Christian; Panzer, Stefan

2010-01-01

Data from speed skating during World Cup 1,500-m middle-distance races were analyzed to (a) determine the time/velocity distribution during the race and (b) assess the impact of time spent in several race sectors on performance outcome. Absolute and relative sector times for the first 300 m (S1) and the following three 400-m laps (S2-S4) and their…

Early Life Manipulations Alter Learning and Memory in Rats

PubMed Central

Kosten, Therese A; Kim, Jeansok J; Lee, Hongjoo J.

2012-01-01

Much research shows early life manipulations have enduring behavioral, neural, and hormonal effects. However, findings of learning and memory performance vary widely across studies. We reviewed studies in which pre-weaning rat pups were exposed to stressors and tested on learning and memory tasks in adulthood. Tasks were classified as aversive conditioning, inhibitory learning, or spatial/relational memory. Variables of duration, type, and timing of neonatal manipulation and sex and strain of animals were examined to determine if any predict enhanced or impaired performance. Brief separations enhanced and prolonged separations impaired performance on spatial/relational tasks. Performance was impaired in aversive conditioning and enhanced in inhibitory learning tasks regardless of manipulation duration. Opposing effects on performance for spatial/relational memory also depended upon timing of manipulation. Enhanced performance was likely if the manipulation occurred during postnatal week 3 but performance was impaired if it was confined to the first two postnatal weeks. Thus, the relationship between early life experiences and adulthood learning and memory performance is multifaceted and decidedly task-dependent. PMID:22819985

Motor Timing Deficits in Sequential Movements in Parkinson Disease Are Related to Action Planning: A Motor Imagery Study

PubMed Central

Avanzino, Laura; Pelosin, Elisa; Martino, Davide; Abbruzzese, Giovanni

2013-01-01

Timing of sequential movements is altered in Parkinson disease (PD). Whether timing deficits in internally generated sequential movements in PD depends also on difficulties in motor planning, rather than merely on a defective ability to materially perform the planned movement is still undefined. To unveil this issue, we adopted a modified version of an established test for motor timing, i.e. the synchronization–continuation paradigm, by introducing a motor imagery task. Motor imagery is thought to involve mainly processes of movement preparation, with reduced involvement of end-stage movement execution-related processes. Fourteen patients with PD and twelve matched healthy volunteers were asked to tap in synchrony with a metronome cue (SYNC) and then, when the tone stopped, to keep tapping, trying to maintain the same rhythm (CONT-EXE) or to imagine tapping at the same rhythm, rather than actually performing it (CONT-MI). We tested both a sub-second and a supra-second inter-stimulus interval between the cues. Performance was recorded using a sensor-engineered glove and analyzed measuring the temporal error and the interval reproduction accuracy index. PD patients were less accurate than healthy subjects in the supra-second time reproduction task when performing both continuation tasks (CONT-MI and CONT-EXE), whereas no difference was detected in the synchronization task and on all tasks involving a sub-second interval. Our findings suggest that PD patients exhibit a selective deficit in motor timing for sequential movements that are separated by a supra-second interval and that this deficit may be explained by a defect of motor planning. Further, we propose that difficulties in motor planning are of a sufficient degree of severity in PD to affect also the motor performance in the supra-second time reproduction task. PMID:24086534

Integrated software health management for aerospace guidance, navigation, and control systems: A probabilistic reasoning approach

NASA Astrophysics Data System (ADS)

Mbaya, Timmy

Embedded Aerospace Systems have to perform safety and mission critical operations in a real-time environment where timing and functional correctness are extremely important. Guidance, Navigation, and Control (GN&C) systems substantially rely on complex software interfacing with hardware in real-time; any faults in software or hardware, or their interaction could result in fatal consequences. Integrated Software Health Management (ISWHM) provides an approach for detection and diagnosis of software failures while the software is in operation. The ISWHM approach is based on probabilistic modeling of software and hardware sensors using a Bayesian network. To meet memory and timing constraints of real-time embedded execution, the Bayesian network is compiled into an Arithmetic Circuit, which is used for on-line monitoring. This type of system monitoring, using an ISWHM, provides automated reasoning capabilities that compute diagnoses in a timely manner when failures occur. This reasoning capability enables time-critical mitigating decisions and relieves the human agent from the time-consuming and arduous task of foraging through a multitude of isolated---and often contradictory---diagnosis data. For the purpose of demonstrating the relevance of ISWHM, modeling and reasoning is performed on a simple simulated aerospace system running on a real-time operating system emulator, the OSEK/Trampoline platform. Models for a small satellite and an F-16 fighter jet GN&C (Guidance, Navigation, and Control) system have been implemented. Analysis of the ISWHM is then performed by injecting faults and analyzing the ISWHM's diagnoses.

The Impact of Library Resource Utilization on Undergraduate Students' Academic Performance: A Propensity Score Matching Design

ERIC Educational Resources Information Center

Kot, Felly Chiteng; Jones, Jennifer L.

2015-01-01

This study uses three cohorts of first-time, full-time undergraduate students (N = 8,652) at a large, metropolitan, public research university to examine the impact of student use of three library resources (workstations, study rooms, and research clinics) on academic performance. To deal with self-selection bias and estimate this impact more…

Ada (Tradename) Compiler Validation Summary Report. Harris Corporation. HARRIS Ada Compiler, Version 1.0. Harris H1200 and H800.

DTIC Science & Technology

This Validations Summary Report (VSR) summarizes the results and conclusions of validation testing performed on the HARRIS Ada Compiler, Version 1.0...at compile time, at link time, or during execution. On-site testing was performed 28 APR 1986 through 30 APR 1986 at Harris Corporation, Ft. Lauderdale

Evaluation of response to bovine viral diarrhea virus type 2 vaccination and timing of weaning on yearling ultrasound body composition, performance, and carcass quality traits in Angus calves

USDA-ARS?s Scientific Manuscript database

There are concerns about antagonisms between immunity and animal productivity in livestock production. The objective of this study was to evaluate the effect of antibody levels through a response to vaccination protocol, weaning timing, and their interaction on performance and carcass quality traits...

Effects of and Preference for Pay for Performance: An Analogue Analysis

ERIC Educational Resources Information Center

Long, Robert D., III; Wilder, David A.; Betz, Alison; Dutta, Ami

2012-01-01

We examined the effects of 2 payment systems on the rate of check processing and time spent on task by participants in a simulated work setting. Three participants experienced individual pay-for-performance (PFP) without base pay and pay-for-time (PFT) conditions. In the last phase, we asked participants to choose which system they preferred. For…

Interpreting Secondary Students' Performance on a Timed, Multiple-Choice Reading Comprehension Assessment: The Prevalence and Impact of Non-Attempted Items

ERIC Educational Resources Information Center

Clemens, Nathan H.; Davis, John L.; Simmons, Leslie E.; Oslund, Eric L.; Simmons, Deborah C.

2015-01-01

Standardized measures are often used as an index of students' reading comprehension and scores have important implications, particularly for students who perform below expectations. This study examined secondary-level students' patterns of responding and the prevalence and impact of non-attempted items on a timed, group-administered,…

How work-self conflict/facilitation influences exhaustion and task performance: A three-wave study on the role of personal resources.

PubMed

Demerouti, Evangelia; Sanz-Vergel, Ana Isabel; Petrou, Paraskevas; van den Heuvel, Machteld

2016-10-01

Although work and family are undoubtedly important life domains, individuals are also active in other life roles which are also important to them (like pursuing personal interests). Building on identity theory and the resource perspective on work-home interface, we examined whether there is an indirect effect of work-self conflict/facilitation on exhaustion and task performance over time through personal resources (i.e., self-efficacy and optimism). The sample was composed of 368 Dutch police officers. Results of the 3-wave longitudinal study confirmed that work-self conflict was related to lower levels of self-efficacy, whereas work-self facilitation was related to improved optimism over time. In turn, self-efficacy was related to higher task performance, whereas optimism was related to diminished levels of exhaustion over time. Further analysis supported the negative, indirect effect of work-self facilitation on exhaustion through optimism over time, and only a few reversed causal effects emerged. The study contributes to the literature on interrole management by showing the role of personal resources in the process of conflict or facilitation over time. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

High-performance electronics for time-of-flight PET systems

NASA Astrophysics Data System (ADS)

Choong, W.-S.; Peng, Q.; Vu, C. Q.; Turko, B. T.; Moses, W. W.

2013-01-01

We have designed and built a high-performance readout electronics system for time-of-flight positron emission tomography (TOF PET) cameras. The electronics architecture is based on the electronics for a commercial whole-body PET camera (Siemens/CPS Cardinal electronics), modified to improve the timing performance. The fundamental contributions in the electronics that can limit the timing resolution include the constant fraction discriminator (CFD), which converts the analog electrical signal from the photo-detector to a digital signal whose leading edge is time-correlated with the input signal, and the time-to-digital converter (TDC), which provides a time stamp for the CFD output. Coincident events are identified by digitally comparing the values of the time stamps. In the Cardinal electronics, the front-end processing electronics are performed by an Analog subsection board, which has two application-specific integrated circuits (ASICs), each servicing a PET block detector module. The ASIC has a built-in CFD and TDC. We found that a significant degradation in the timing resolution comes from the ASIC's CFD and TDC. Therefore, we have designed and built an improved Analog subsection board that replaces the ASIC's CFD and TDC with a high-performance CFD (made with discrete components) and TDC (using the CERN high-performance TDC ASIC). The improved Analog subsection board is used in a custom single-ring LSO-based TOF PET camera. The electronics system achieves a timing resolution of 60 ps FWHM. Prototype TOF detector modules are read out with the electronics system and give coincidence timing resolutions of 259 ps FWHM and 156 ps FWHM for detector modules coupled to LSO and LaBr3 crystals respectively.

High-performance electronics for time-of-flight PET systems.

PubMed

Choong, W-S; Peng, Q; Vu, C Q; Turko, B T; Moses, W W

2013-01-01

We have designed and built a high-performance readout electronics system for time-of-flight positron emission tomography (TOF PET) cameras. The electronics architecture is based on the electronics for a commercial whole-body PET camera (Siemens/CPS Cardinal electronics), modified to improve the timing performance. The fundamental contributions in the electronics that can limit the timing resolution include the constant fraction discriminator (CFD), which converts the analog electrical signal from the photo-detector to a digital signal whose leading edge is time-correlated with the input signal, and the time-to-digital converter (TDC), which provides a time stamp for the CFD output. Coincident events are identified by digitally comparing the values of the time stamps. In the Cardinal electronics, the front-end processing electronics are performed by an Analog subsection board, which has two application-specific integrated circuits (ASICs), each servicing a PET block detector module. The ASIC has a built-in CFD and TDC. We found that a significant degradation in the timing resolution comes from the ASIC's CFD and TDC. Therefore, we have designed and built an improved Analog subsection board that replaces the ASIC's CFD and TDC with a high-performance CFD (made with discrete components) and TDC (using the CERN high-performance TDC ASIC). The improved Analog subsection board is used in a custom single-ring LSO-based TOF PET camera. The electronics system achieves a timing resolution of 60 ps FWHM. Prototype TOF detector modules are read out with the electronics system and give coincidence timing resolutions of 259 ps FWHM and 156 ps FWHM for detector modules coupled to LSO and LaBr 3 crystals respectively.

Impact of the initial classic section during a simulated cross-country skiing skiathlon on the cardiopulmonary responses during the subsequent period of skate skiing.

PubMed

Mourot, Laurent; Fabre, Nicolas; Andersson, Erik; Willis, Sarah J; Hébert-Losier, Kim; Holmberg, Hans-Christer

2014-08-01

The aim of this study was to assess potential changes in the performance and cardiorespiratory responses of elite cross-country skiers following transition from the classic (CL) to the skating (SK) technique during a simulated skiathlon. Eight elite male skiers performed two 6 km (2 × 3 km) roller-skiing time trials on a treadmill at racing speed: one starting with the classic and switching to the skating technique (CL1-SK2) and another employing the skating technique throughout (SK1-SK2), with continuous monitoring of gas exchanges, heart rates, and kinematics (video). The overall performance times in the CL1-SK2 (21:12 ± 1:24) and SK1-SK2 (20:48 ± 2:00) trials were similar, and during the second section of each performance times and overall cardiopulmonary responses were also comparable. However, in comparison with SK1-SK2, the CL1-SK2 trial involved significantly higher increases in minute ventilation (V̇E, 89.8 ± 26.8 vs. 106.8 ± 17.6 L·min(-1)) and oxygen uptake (V̇O2; 3.1 ± 0.8 vs 3.5 ± 0.5 L·min(-1)) 2 min after the transition as well as longer time constants for V̇E, V̇O2, and heart rate during the first 3 min after the transition. This higher cardiopulmonary exertion was associated with ∼3% faster cycle rates. In conclusion, overall performance during the 2 time trials did not differ. The similar performance times during the second sections were achieved with comparable mean cardiopulmonary responses. However, the observation that during the initial 3-min post-transition following classic skiing cardiopulmonary responses and cycle rates were slightly higher supports the conclusion that an initial section of classic skiing exerts an impact on performance during a subsequent section of skate skiing.

Emergency skill training--a randomized controlled study on the effectiveness of the 4-stage approach compared to traditional clinical teaching.

PubMed

Greif, Robert; Egger, Lars; Basciani, Reto M; Lockey, Andrew; Vogt, Andreas

2010-12-01

The "4-stage approach" has been widely accepted for practical skill training replacing the traditional 2 stages ("see one, do one"). However, the superior effectiveness of the 4-stage approach was never proved. To evaluate whether skill training with the 4-stage approach results in shorter performance time needed for a successful percutaneous needle-puncture cricothyroidotomy, and consequently in a reduced number of attempts needed to perform the skill in <60s compared to traditional teaching. Randomized controlled single-blinded parallel group study at the University Hospital Bern. With IRB approval and informed consent 128 undergraduate medical students were randomized in four groups: traditional teaching, no stage 2, no stage 3, and 4-stage approach for the training of cricothyroidotomy. Everyone watched a video of the cricothyroidotomy as stage 1 followed by skill training in the respective teaching group. Participants had to perform the cricothyroidotomy 10 times on skin-covered pig larynxes. Performance time was measured from skin palpation to trachea ventilation. Study participants filled out a self-rating on competency during the training. Performance time for each attempt was comparable in all groups and improved similarly to reach a performance time of <60 s. Self-rating revealed that all groups felt equally competent throughout. Even if the 4-stage approach is widely accepted and used as a didactic method for skill teaching we could not find evidence that its use or omitting stage 2 or 3 results in superior learning of an emergency skill compared to traditional teaching. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Does a multicomponent exercise program improve dual-task performance in amnestic mild cognitive impairment? A randomized controlled trial.

PubMed

Makizako, Hyuma; Doi, Takehiko; Shimada, Hiroyuki; Yoshida, Daisuke; Tsutsumimoto, Kota; Uemura, Kazuki; Suzuki, Takao

2012-12-01

There has been much interest in exercise interventions as a primary behavioral prevention strategy against cognitive decline. The aim of this study was to evaluate the effect of a multicomponent exercise program on physical and dual-task performances in community-dwelling older adults with amnestic mild cognitive impairment (aMCI). Fifty older adults (23 women) with aMCI (mean age, 76 years) were randomized to an intervention (n=25) or a control group (n=25). The intervention group received a multicomponent exercise program for 90 minutes/day, 2 days/week, or 40 times over six months. The multicomponent exercises included aerobic exercise, muscle strength training and postural balance retraining, which was conducted under multi-task conditions to stimulate attention and memory. Participants in the control group attended two health promotion education classes within six months. Physical and dual-task performances were measured before randomization and after six months. Dual-task performances using reaction times with balance and cognitive demands were measured. The improvement effects on dual-task performances with both balance and cognitive demands were not statistically significant: reaction time with balance demand F1,45=3.3, p=0.07, and cognitive demand F1,45=2.6, p=0.12. However, there was a significant group-by-time interaction on maximal walking speed, which decreased significantly in the control group (F1,45=5.9, p=0.02). This six-month multicomponent exercise program improved maximal walking speed in older adults with aMCI; however, it did not improve dual-task performances assessed by reaction times.

The effect of different training exercises on the performance outcome on the da Vinci Skills Simulator.

PubMed

Walliczek-Dworschak, U; Schmitt, M; Dworschak, P; Diogo, I; Ecke, A; Mandapathil, M; Teymoortash, A; Güldner, C

2017-06-01

Increasing usage of robotic surgery presents surgeons with the question of how to acquire the special skills required. This study aimed to analyze the effect of different exercises on their performance outcomes. This prospective study was conducted on the da Vinci Skills Simulator from December 2014 till August 2015. Sixty robotic novices were included and randomized to three groups of 20 participants each. Each group performed three different exercises with comparable difficulty levels. The exercises were performed three times in a row within two training sessions, with an interval of 1 week in between. On the final training day, two new exercises were added and a questionnaire was completed. Technical metrics of performance (overall score, time to complete, economy of motion, instrument collisions, excessive instrument force, instruments out of view, master work space range, drops, missed targets, misapplied energy time, blood loss and broken vessels) were recorded by the simulator software for further analysis. Training with different exercises led to comparable results in performance metrics for the final exercises among the three groups. A significant skills gain was recorded between the first and last exercises, with improved performance in overall score, time to complete and economy of motion for all exercises in all three groups. As training with different exercises led to comparable results in robotic training, the type of exercise seems to play a minor role in the outcome. For a robotic training curriculum, it might be important to choose exercises with comparable difficulty levels. In addition, it seems to be advantageous to limit the duration of the training to maintain the concentration throughout the entire session.

Effects of reward and punishment on task performance, mood and autonomic nervous function, and the interaction with personality.

PubMed

Sakuragi, Sokichi; Sugiyama, Yoshiki

2009-06-01

The effects of reward and punishment are different, and there are individual differences in sensitivity to reward and punishment. The purpose of this study was to investigate the effects of reward and punishment on task performance, mood, and autonomic nervous function, along with the interaction with personality. Twenty-one healthy female subjects volunteered for the experiment. The task performance was evaluated by required time and total errors while performing a Wisconsin Card Sorting Test. We assessed their personalities using the Minnesota Multiphasic Personality Inventory (MMPI) questionnaire, and mood states by a profile of mood states. Autonomic nervous function was estimated by a spectral analysis of heart rate variability, baroreflex sensitivity, and blood pressure. Repeated measures analysis of variance (ANOVA) revealed significant interaction of condition x time course on mood and autonomic nervous activity, which would indicate a less stressed state under the rewarding condition, but revealed no significant interaction of condition x time course on the task performance. The interactions with personality were further analyzed by repeated measures ANOVA applying the clinical scales of MMPI as independent variables, and significant interactions of condition x time course x Pt (psychasthenia) on task performance, mood, and blood pressure, were revealed. That is, the high Pt group, whose members tend to be sensitive and prone to worry, showed gradual improvement of task performance under the punishing situation with slight increase in systolic blood pressure, while showed no improvement under the rewarding situation with fatigue sense attenuation. In contrast, the low Pt group, whose members tend to be adaptive and self-confident, showed gradual improvement under the rewarding situation. Therefore, we should carefully choose the strategy of reward or punishment, considering the interaction with personality as well as the context in which it is given.

The influence of time on task on mind wandering and visual working memory.

PubMed

Krimsky, Marissa; Forster, Daniel E; Llabre, Maria M; Jha, Amishi P

2017-12-01

Working memory relies on executive resources for successful task performance, with higher demands necessitating greater resource engagement. In addition to mnemonic demands, prior studies suggest that internal sources of distraction, such as mind wandering (i.e., having off-task thoughts) and greater time on task, may tax executive resources. Herein, the consequences of mnemonic demand, mind wandering, and time on task were investigated during a visual working memory task. Participants (N=143) completed a delayed-recognition visual working memory task, with mnemonic load for visual objects manipulated across trials (1 item=low load; 2 items=high load) and subjective mind wandering assessed intermittently throughout the experiment using a self-report Likert-type scale (1=on-task, 6=off-task). Task performance (correct/incorrect response) and self-reported mind wandering data were evaluated by hierarchical linear modeling to track trial-by-trial fluctuations. Performance declined with greater time on task, and the rate of decline was steeper for high vs low load trials. Self-reported mind wandering increased over time, and significantly varied asa function of both load and time on task. Participants reported greater mind wandering at the beginning of the experiment for low vs. high load trials; however, with greater time on task, more mind wandering was reported during high vs. low load trials. These results suggest that the availability of executive resources in support of working memory maintenance processes fluctuates in a demand-sensitive manner with time on task, and may be commandeered by mind wandering. Copyright © 2017 Elsevier B.V. All rights reserved.

The LINC-NIRVANA fringe and flexure tracker: Linux real-time solutions

NASA Astrophysics Data System (ADS)

Wang, Yeping; Bertram, Thomas; Straubmeier, Christian; Rost, Steffen; Eckart, Andreas

2006-06-01

The correction of atmospheric differential piston and instrumental flexure effects is mandatory for optimum interferometric performance of the LBT NIR interferometric imaging camera LINC-NIRVANA. The task of the Fringe and Flexure Tracking System (FFTS) is to detect and correct these effects in a real-time closed loop. On a timescale of milliseconds, image data of the order of 4K bytes has to be retrieved from the FFTS detector, analyzed, and the results have to be sent to the control system. The need for a reliable communication between several processes within a confined period of time calls for solutions with good real-time performance. We investigated two soft real-time options for the Linux platform. The design we present takes advantage of several features that follow the POSIX standard with improved real-time performance, which were implemented in the new Linux kernel (2.6.12). Several concepts, such as synchronization, shared memory, and preemptive scheduling are considered and the performance of the most time-critical parts of the FFTS software is tested.

Simulation of reaction diffusion processes over biologically relevant size and time scales using multi-GPU workstations

PubMed Central

Hallock, Michael J.; Stone, John E.; Roberts, Elijah; Fry, Corey; Luthey-Schulten, Zaida

2014-01-01

Simulation of in vivo cellular processes with the reaction-diffusion master equation (RDME) is a computationally expensive task. Our previous software enabled simulation of inhomogeneous biochemical systems for small bacteria over long time scales using the MPD-RDME method on a single GPU. Simulations of larger eukaryotic systems exceed the on-board memory capacity of individual GPUs, and long time simulations of modest-sized cells such as yeast are impractical on a single GPU. We present a new multi-GPU parallel implementation of the MPD-RDME method based on a spatial decomposition approach that supports dynamic load balancing for workstations containing GPUs of varying performance and memory capacity. We take advantage of high-performance features of CUDA for peer-to-peer GPU memory transfers and evaluate the performance of our algorithms on state-of-the-art GPU devices. We present parallel e ciency and performance results for simulations using multiple GPUs as system size, particle counts, and number of reactions grow. We also demonstrate multi-GPU performance in simulations of the Min protein system in E. coli. Moreover, our multi-GPU decomposition and load balancing approach can be generalized to other lattice-based problems. PMID:24882911

Simulation of reaction diffusion processes over biologically relevant size and time scales using multi-GPU workstations.

PubMed

Hallock, Michael J; Stone, John E; Roberts, Elijah; Fry, Corey; Luthey-Schulten, Zaida

2014-05-01

Simulation of in vivo cellular processes with the reaction-diffusion master equation (RDME) is a computationally expensive task. Our previous software enabled simulation of inhomogeneous biochemical systems for small bacteria over long time scales using the MPD-RDME method on a single GPU. Simulations of larger eukaryotic systems exceed the on-board memory capacity of individual GPUs, and long time simulations of modest-sized cells such as yeast are impractical on a single GPU. We present a new multi-GPU parallel implementation of the MPD-RDME method based on a spatial decomposition approach that supports dynamic load balancing for workstations containing GPUs of varying performance and memory capacity. We take advantage of high-performance features of CUDA for peer-to-peer GPU memory transfers and evaluate the performance of our algorithms on state-of-the-art GPU devices. We present parallel e ciency and performance results for simulations using multiple GPUs as system size, particle counts, and number of reactions grow. We also demonstrate multi-GPU performance in simulations of the Min protein system in E. coli . Moreover, our multi-GPU decomposition and load balancing approach can be generalized to other lattice-based problems.

Prospects for a precision timing upgrade of the CMS PbWO crystal electromagnetic calorimeter for the HL-LHC

NASA Astrophysics Data System (ADS)

Massironi, A.

2018-04-01

The upgrade of the Compact Muon Solenoid (CMS) crystal electromagnetic calorimeter (ECAL), which will operate at the High Luminosity Large Hadron Collider (HL-LHC), will achieve a timing resolution of around 30 ps for high energy photons and electrons. In this talk we will discuss the benefits of precision timing for the ECAL event reconstruction at HL-LHC. Simulation studies focused on the timing properties of PbWO4 crystals, as well as the impact of the photosensors and the readout electronics on the timing performance, will be presented. Test beam studies intended to measure the timing performance of the PbWO4 crystals with different photosensors and readout electronics will be shown.

Effects of Total SAT® Test Time on Performance and Fatigue. Research Notes. RN-37

ERIC Educational Resources Information Center

Ackerman, Phillip L.; Kanfer, Ruth; Wolman, Stacey D.

2005-01-01

The current study was designed to examine performance effects and fatigue effects associated with different total SAT testing times. In addition, the researchers examined personality, motivation, and other determinants of individual differences in examinee fatigue before, during, and after testing.

Are Full-Time MBAs Performing?

ERIC Educational Resources Information Center

Rowland, Caroline Ann; Hall, Roger David

2012-01-01

Full-time MBA students amount to about one-third of the 26,000 students enrolled on MBA programmes at UK universities. The programmes have become increasingly international in student composition and concerns have been expressed about performance, quality and comparability between programmes. Research into predictors of MBA success has been…

Effect of Overhydration on Time-Trial Swim Performance.

ERIC Educational Resources Information Center

Maresh, Carl M.; Bergeron, Michael E.; Kenefick, Robert W.; Castellani, John W.; Hoffman, Jay R.; Armstrong, Lawrence E.

2001-01-01

Examined whether moderate overhydration would enhance the performance of otherwise euhydrated collegiate swimmers during two 183-meter time-trial swims held 3 days apart. Participants swam in alternate, randomized euhydrated, and overhydrated states. Results indicated that euhydration before an intense, short-duration swim was adequate for peak…

Microprocessor utilization in search and rescue missions

NASA Technical Reports Server (NTRS)

Schwartz, M.

1977-01-01

The feasibility of performing the same task in real time using microprocessor technology was determined. The least square algorithm was implemented on an Intel 8080 microprocessor. Results indicated that a microprocessor could easily match the IBM implementation in accuracy and be performed inside the time limitations set.

Experimental investigation of stress-inducing properties of system response times.

PubMed

Kuhmann, W

1989-03-01

System response times are regarded as a major stressor in human-computer interaction. In two earlier studies short (2s) and long (8s) response times were found to have differential effects on psychological, subjective, and performance variables, but results did not favour either response time. Therefore, in another laboratory study with 48 subjects in four independent groups working at a stimulated computer workplace, system response times of 2, 4, 6 and 8s were introduced in the same error detection task as used before, during 3 training and 5 working trials of 20 min each, and the same physiological, subjective and performance measures were obtained. There were no global effects on physiological variables, possibly due to low work load as a result of missing time pressure, but subjective and performance variables clearly favoured the longer system response times. When task periods and response time-periods were analysed separately, a shift of electrodermal activity could be observed from task- to response time-periods during the course of trials in the 8s condition. This did not appear in any other condition, which points to psychophysiological excitement that develops when system response times are too long, thus providing support for the concept of optimal system response times.

Effect of time span and task load on pilot mental workload

NASA Technical Reports Server (NTRS)

Berg, S. L.; Sheridan, T. B.

1986-01-01

Two sets of simulations designed to examine how a pilot's mental workload is affected by continuous manual-control activity versus discrete mental tasks that included the length of time between receiving an assignment and executing it are described. The first experiment evaluated two types of measures: objective performance indicators and subjective ratings. Subjective ratings for the two missions were different, but the objective performance measures were similar. In the second experiments, workload levels were increased and a second performance measure was taken. Mental workload had no influence on either performance-based workload measure. Subjective ratings discriminated among the scenarios and correlated with performance measures for high-workload flights. The number of mental tasks performed did not influence error rates, although high manual workloads did increase errors.

A cloud masking algorithm for EARLINET lidar systems

NASA Astrophysics Data System (ADS)

Binietoglou, Ioannis; Baars, Holger; D'Amico, Giuseppe; Nicolae, Doina

2015-04-01

Cloud masking is an important first step in any aerosol lidar processing chain as most data processing algorithms can only be applied on cloud free observations. Up to now, the selection of a cloud-free time interval for data processing is typically performed manually, and this is one of the outstanding problems for automatic processing of lidar data in networks such as EARLINET. In this contribution we present initial developments of a cloud masking algorithm that permits the selection of the appropriate time intervals for lidar data processing based on uncalibrated lidar signals. The algorithm is based on a signal normalization procedure using the range of observed values of lidar returns, designed to work with different lidar systems with minimal user input. This normalization procedure can be applied to measurement periods of only few hours, even if no suitable cloud-free interval exists, and thus can be used even when only a short period of lidar measurements is available. Clouds are detected based on a combination of criteria including the magnitude of the normalized lidar signal and time-space edge detection performed using the Sobel operator. In this way the algorithm avoids misclassification of strong aerosol layers as clouds. Cloud detection is performed using the highest available time and vertical resolution of the lidar signals, allowing the effective detection of low-level clouds (e.g. cumulus humilis). Special attention is given to suppress false cloud detection due to signal noise that can affect the algorithm's performance, especially during day-time. In this contribution we present the details of algorithm, the effect of lidar characteristics (space-time resolution, available wavelengths, signal-to-noise ratio) to detection performance, and highlight the current strengths and limitations of the algorithm using lidar scenes from different lidar systems in different locations across Europe.