Success in Real-Time: Using Real-Time Labor Market Information to Build Better Middle-Skill STEM Pathways. Executive Summary

ERIC Educational Resources Information Center

Rosenblum, Ian; Spence, Christopher

2015-01-01

The gap that separates so many workers from the prospect of good-paying, stable jobs demands urgent action by states--even as the unrelenting fast pace of economic change makes a sound response all the more difficult and as the "rules of the game" continue to evolve. This is especially true in the Science, Technology, Engineering and…

Open source acceleration of wave optics simulations on energy efficient high-performance computing platforms

NASA Astrophysics Data System (ADS)

Beck, Jeffrey; Bos, Jeremy P.

2017-05-01

We compare several modifications to the open-source wave optics package, WavePy, intended to improve execution time. Specifically, we compare the relative performance of the Intel MKL, a CPU based OpenCV distribution, and GPU-based version. Performance is compared between distributions both on the same compute platform and between a fully-featured computing workstation and the NVIDIA Jetson TX1 platform. Comparisons are drawn in terms of both execution time and power consumption. We have found that substituting the Fast Fourier Transform operation from OpenCV provides a marked improvement on all platforms. In addition, we show that embedded platforms offer some possibility for extensive improvement in terms of efficiency compared to a fully featured workstation.

Mental Rotation of Tactical Instruction Displays Affects Information Processing Demand and Execution Accuracy in Basketball.

PubMed

Koopmann, Till; Steggemann-Weinrich, Yvonne; Baumeister, Jochen; Krause, Daniel

2017-09-01

In sports games, coaches often use tactic boards to present tactical instructions during time-outs (e.g., 20 s to 60 s in basketball). Instructions should be presented in a way that enables fast and errorless information processing for the players. The aim of this study was to test the effect of different orientations of visual tactical displays on observation time and execution performance. High affordances in visual-spatial transformation (e.g., mental rotation processes) might impede information processing and might decrease execution performance with regard to the instructed playing patterns. In a within-subjects design with 1 factor, 10 novice students were instructed with visual tactical instructions of basketball playing patterns with different orientations either showing the playing pattern with low spatial disparity to the players' on-court perspective (basket on top) or upside down (basket on bottom). The self-chosen time for watching the pattern before execution was significantly shorter and spatial accuracy in pattern execution was significantly higher when the instructional perspective and the real perspective on the basketball court had a congruent orientation. The effects might be explained by interfering mental rotation processes that are necessary to transform the instructional perspective into the players' actual perspective while standing on the court or imagining themselves standing on the court. According to these results, coaches should align their tactic boards to their players' on-court viewing perspective.

Designing a Syntax-Based Retrieval System for Supporting Language Learning

ERIC Educational Resources Information Center

Tsao, Nai-Lung; Kuo, Chin-Hwa; Wible, David; Hung, Tsung-Fu

2009-01-01

In this paper, we propose a syntax-based text retrieval system for on-line language learning and use a fast regular expression search engine as its main component. Regular expression searches provide more scalable querying and search results than keyword-based searches. However, without a well-designed index scheme, the execution time of regular…

Children's executive function and high-calorie, low-nutrient food intake: mediating effects of child-perceived adult fast food intake.

PubMed

Tate, Eleanor B; Unger, Jennifer B; Chou, Chih-Ping; Spruijt-Metz, Donna; Pentz, Mary Ann; Riggs, Nathaniel R

2015-04-01

This study tested the relationships among child executive function (EF), child-perceived parent fast food intake, and child self-reported subsequent consumption of high-calorie, low-nutrient (HCLN) food. One year and 6-month longitudinal observation from a larger randomized controlled trial. Southern California elementary schools. Fourth- and fifth-grade children (N = 1,005) participating in the Pathways to Health obesity prevention program. Child EF problems were associated with higher concurrent HCLN intake (B = 0.29, SE = 0.10, p < .001) and had a significant indirect effect through higher perceived frequency of parent fast food intake (indirect effect = 0.17, 95% confidence interval [CI] = [0.11, 0.25], p < .001). Longitudinally, child EF problems did not significantly predict higher HCLN intake a year and a half later (B = 0.01, SE = 0.10, p = .92, n = 848) but did have a significant indirect effect through higher perceived parent fast food intake (indirect effect = 0.05, 95% CI = [0.02, 0.10], p < .001). Children's EF difficulties may increase their perception of parent concurrent fast food intake, contributing to their own unhealthy food intake. However, EF problems may not directly affect HCLN intake across time, except when problems are associated with child perception of more frequent parent consumption of convenience foods. Future research is needed to investigate the possibility that helping children perceive and understand role models' convenience food consumption may improve child dietary consumption patterns. © 2014 Society for Public Health Education.

Diabetes, impaired fasting glucose, and cognitive decline in a population of elderly community residents.

PubMed

Rouch, Isabelle; Roche, Frédéric; Dauphinot, Virginie; Laurent, Bernard; Antérion, Catherine Thomas; Celle, Sébastien; Krolak-Salmon, Pierre; Barthélémy, Jean-Claude

2012-08-01

Diabetes and impaired fasting glucose, as well as cognitive impairment, are common in the elderly. Although several cross-sectional studies have demonstrated the influence of diabetes on cognitive impairment, only a few longitudinal studies have assessed the relationship between diabetes, impaired fasting glucose and cognitive decline in non-demented elderly community dwellers, by means of extensive neuropsychological batteries. The present study assesses the relationship between baseline diabetes, impaired fasting glucose (IFG) and 2- year evolution of memory, attention and executive performance in a sample of non-demented elderly subjects. Population-based cohort study [(PROgnostic indicator OF cardiovascular and cerebrovascular events (PROOF)]. One hundred and sixty-three community dwellers aged 65 years without dementia at recruitment. Memory, attention and executive performance. A significant association was observed between baseline diabetes mellitus and a higher 2-year decline in the Trial Making Test B and Stroop test exploring attention and executive function. This effect remained significant after adjusting for age, gender, education, anxiety and depressive symptoms, as well as other cardiovascular risk factors (F=2.41; p=0.007). Instead, no relationship was observed between IFG and cognitive decline. Our study showed that, in a sample of elderly non-demented community dwellers, diabetes mellitus (but not IFG) is associated with a higher decline in selective attention and executive functioning. These results emphasize the importance of detecting and man- aging diabetes and impaired fasting glucose, in order to prevent cognitive impairment and dementia.

Image Display and Manipulation System (IDAMS) program documentation, Appendixes A-D. [including routines, convolution filtering, image expansion, and fast Fourier transformation

NASA Technical Reports Server (NTRS)

Cecil, R. W.; White, R. A.; Szczur, M. R.

1972-01-01

The IDAMS Processor is a package of task routines and support software that performs convolution filtering, image expansion, fast Fourier transformation, and other operations on a digital image tape. A unique task control card for that program, together with any necessary parameter cards, selects each processing technique to be applied to the input image. A variable number of tasks can be selected for execution by including the proper task and parameter cards in the input deck. An executive maintains control of the run; it initiates execution of each task in turn and handles any necessary error processing.

qtcm 0.1.2: A Python Implementation of the Neelin-Zeng Quasi-Equilibrium Tropical Circulation model

NASA Astrophysics Data System (ADS)

Lin, J. W.-B.

2008-10-01

Historically, climate models have been developed incrementally and in compiled languages like Fortran. While the use of legacy compiled languages results in fast, time-tested code, the resulting model is limited in its modularity and cannot take advantage of functionality available with modern computer languages. Here we describe an effort at using the open-source, object-oriented language Python to create more flexible climate models: the package qtcm, a Python implementation of the intermediate-level Neelin-Zeng Quasi-Equilibrium Tropical Circulation model (QTCM1) of the atmosphere. The qtcm package retains the core numerics of QTCM1, written in Fortran to optimize model performance, but uses Python structures and utilities to wrap the QTCM1 Fortran routines and manage model execution. The resulting "mixed language" modeling package allows order and choice of subroutine execution to be altered at run time, and model analysis and visualization to be integrated in interactively with model execution at run time. This flexibility facilitates more complex scientific analysis using less complex code than would be possible using traditional languages alone, and provides tools to transform the traditional "formulate hypothesis → write and test code → run model → analyze results" sequence into a feedback loop that can be executed automatically by the computer.

qtcm 0.1.2: a Python implementation of the Neelin-Zeng Quasi-Equilibrium Tropical Circulation Model

NASA Astrophysics Data System (ADS)

Lin, J. W.-B.

2009-02-01

Historically, climate models have been developed incrementally and in compiled languages like Fortran. While the use of legacy compiled languages results in fast, time-tested code, the resulting model is limited in its modularity and cannot take advantage of functionality available with modern computer languages. Here we describe an effort at using the open-source, object-oriented language Python to create more flexible climate models: the package qtcm, a Python implementation of the intermediate-level Neelin-Zeng Quasi-Equilibrium Tropical Circulation model (QTCM1) of the atmosphere. The qtcm package retains the core numerics of QTCM1, written in Fortran to optimize model performance, but uses Python structures and utilities to wrap the QTCM1 Fortran routines and manage model execution. The resulting "mixed language" modeling package allows order and choice of subroutine execution to be altered at run time, and model analysis and visualization to be integrated in interactively with model execution at run time. This flexibility facilitates more complex scientific analysis using less complex code than would be possible using traditional languages alone, and provides tools to transform the traditional "formulate hypothesis → write and test code → run model → analyze results" sequence into a feedback loop that can be executed automatically by the computer.

A Python Implementation of an Intermediate-Level Tropical Circulation Model and Implications for How Modeling Science is Done

NASA Astrophysics Data System (ADS)

Lin, J. W. B.

2015-12-01

Historically, climate models have been developed incrementally and in compiled languages like Fortran. While the use of legacy compiledlanguages results in fast, time-tested code, the resulting model is limited in its modularity and cannot take advantage of functionalityavailable with modern computer languages. Here we describe an effort at using the open-source, object-oriented language Pythonto create more flexible climate models: the package qtcm, a Python implementation of the intermediate-level Neelin-Zeng Quasi-Equilibrium Tropical Circulation model (QTCM1) of the atmosphere. The qtcm package retains the core numerics of QTCM1, written in Fortran, to optimize model performance but uses Python structures and utilities to wrap the QTCM1 Fortran routines and manage model execution. The resulting "mixed language" modeling package allows order and choice of subroutine execution to be altered at run time, and model analysis and visualization to be integrated in interactively with model execution at run time. This flexibility facilitates more complex scientific analysis using less complex code than would be possible using traditional languages alone and provides tools to transform the traditional "formulate hypothesis → write and test code → run model → analyze results" sequence into a feedback loop that can be executed automatically by the computer.

A Hierarchical and Distributed Approach for Mapping Large Applications to Heterogeneous Grids using Genetic Algorithms

NASA Technical Reports Server (NTRS)

Sanyal, Soumya; Jain, Amit; Das, Sajal K.; Biswas, Rupak

2003-01-01

In this paper, we propose a distributed approach for mapping a single large application to a heterogeneous grid environment. To minimize the execution time of the parallel application, we distribute the mapping overhead to the available nodes of the grid. This approach not only provides a fast mapping of tasks to resources but is also scalable. We adopt a hierarchical grid model and accomplish the job of mapping tasks to this topology using a scheduler tree. Results show that our three-phase algorithm provides high quality mappings, and is fast and scalable.

GPU and APU computations of Finite Time Lyapunov Exponent fields

NASA Astrophysics Data System (ADS)

Conti, Christian; Rossinelli, Diego; Koumoutsakos, Petros

2012-03-01

We present GPU and APU accelerated computations of Finite-Time Lyapunov Exponent (FTLE) fields. The calculation of FTLEs is a computationally intensive process, as in order to obtain the sharp ridges associated with the Lagrangian Coherent Structures an extensive resampling of the flow field is required. The computational performance of this resampling is limited by the memory bandwidth of the underlying computer architecture. The present technique harnesses data-parallel execution of many-core architectures and relies on fast and accurate evaluations of moment conserving functions for the mesh to particle interpolations. We demonstrate how the computation of FTLEs can be efficiently performed on a GPU and on an APU through OpenCL and we report over one order of magnitude improvements over multi-threaded executions in FTLE computations of bluff body flows.

Determinants of the effectiveness of fast break actions in elite and sub-elite Italian men's basketball games.

PubMed

Conte, D; Favero, T G; Niederhausen, M; Capranica, L; Tessitore, A

2017-06-01

The aim of this study was to examine the determinants of successful and unsuccessful fast-break (FB) actions in elite and sub-elite basketball games. Fifteen 1 st -division (elite) and fifteen 3 rd -division (sub-elite) Italian men's championship games were analysed across two seasons (2012/2013 and 2013/2014). A binary logistic regression analysis was performed, and the fast-break outcome (successful vs. unsuccessful) was adopted as the dependent variable separately in both elite and sub-elite games. FB execution (initiation, advance and completion phases), typology (primary and secondary break) and the number of players involved (equal number or superiority) were used as independent variables. The results showed that the rate of success of FB actions was 63.5% and 59.7% in elite and sub-elite games, respectively. Moreover, successful FBs were more likely to be completed in the lane in relation to unsuccessful ones in both elite and sub-elite games (p<0.05). Finally, descriptive statistics showed that both elite and sub-elite teams executed FBs similarly. This study highlighted that completion zone was the only predictor of a successful fast break in basketball, while the typology and number of players involved did not predict fast break effectiveness. Moreover, elite and sub-elite teams executed fast break actions similarly. These findings might be useful for basketball coaches to optimize the training of FB actions.

Observations & modeling of solar-wind/magnetospheric interactions

NASA Astrophysics Data System (ADS)

Hoilijoki, Sanni; Von Alfthan, Sebastian; Pfau-Kempf, Yann; Palmroth, Minna; Ganse, Urs

2016-07-01

The majority of the global magnetospheric dynamics is driven by magnetic reconnection, indicating the need to understand and predict reconnection processes and their global consequences. So far, global magnetospheric dynamics has been simulated using mainly magnetohydrodynamic (MHD) models, which are approximate but fast enough to be executed in real time or near-real time. Due to their fast computation times, MHD models are currently the only possible frameworks for space weather predictions. However, in MHD models reconnection is not treated kinetically. In this presentation we will compare the results from global kinetic (hybrid-Vlasov) and global MHD simulations. Both simulations are compared with in-situ measurements. We will show that the kinetic processes at the bow shock, in the magnetosheath and at the magnetopause affect global dynamics even during steady solar wind conditions. Foreshock processes cause an asymmetry in the magnetosheath plasma, indicating that the plasma entering the magnetosphere is not symmetrical on different sides of the magnetosphere. Behind the bow shock in the magnetosheath kinetic wave modes appear. Some of these waves propagate to the magnetopause and have an effect on the magnetopause reconnection. Therefore we find that kinetic phenomena have a significant role in the interaction between the solar wind and the magnetosphere. While kinetic models cannot be executed in real time currently, they could be used to extract heuristics to be added in the faster MHD models.

A static data flow simulation study at Ames Research Center

NASA Technical Reports Server (NTRS)

Barszcz, Eric; Howard, Lauri S.

1987-01-01

Demands in computational power, particularly in the area of computational fluid dynamics (CFD), led NASA Ames Research Center to study advanced computer architectures. One architecture being studied is the static data flow architecture based on research done by Jack B. Dennis at MIT. To improve understanding of this architecture, a static data flow simulator, written in Pascal, has been implemented for use on a Cray X-MP/48. A matrix multiply and a two-dimensional fast Fourier transform (FFT), two algorithms used in CFD work at Ames, have been run on the simulator. Execution times can vary by a factor of more than 2 depending on the partitioning method used to assign instructions to processing elements. Service time for matching tokens has proved to be a major bottleneck. Loop control and array address calculation overhead can double the execution time. The best sustained MFLOPS rates were less than 50% of the maximum capability of the machine.

One-dimensional biomass fast pyrolysis model with reaction kinetics integrated in an Aspen Plus Biorefinery Process Model

DOE PAGES

Humbird, David; Trendewicz, Anna; Braun, Robert; ...

2017-01-12

A biomass fast pyrolysis reactor model with detailed reaction kinetics and one-dimensional fluid dynamics was implemented in an equation-oriented modeling environment (Aspen Custom Modeler). Portions of this work were detailed in previous publications; further modifications have been made here to improve stability and reduce execution time of the model to make it compatible for use in large process flowsheets. The detailed reactor model was integrated into a larger process simulation in Aspen Plus and was stable for different feedstocks over a range of reactor temperatures. Sample results are presented that indicate general agreement with experimental results, but with higher gasmore » losses caused by stripping of the bio-oil by the fluidizing gas in the simulated absorber/condenser. Lastly, this integrated modeling approach can be extended to other well-defined, predictive reactor models for fast pyrolysis, catalytic fast pyrolysis, as well as other processes.« less

Method of developing all-optical trinary JK, D-type, and T-type flip-flops using semiconductor optical amplifiers.

PubMed

Garai, Sisir Kumar

2012-04-10

To meet the demand of very fast and agile optical networks, the optical processors in a network system should have a very fast execution rate, large information handling, and large information storage capacities. Multivalued logic operations and multistate optical flip-flops are the basic building blocks for such fast running optical computing and data processing systems. In the past two decades, many methods of implementing all-optical flip-flops have been proposed. Most of these suffer from speed limitations because of the low switching response of active devices. The frequency encoding technique has been used because of its many advantages. It can preserve its identity throughout data communication irrespective of loss of light energy due to reflection, refraction, attenuation, etc. The action of polarization-rotation-based very fast switching of semiconductor optical amplifiers increases processing speed. At the same time, tristate optical flip-flops increase information handling capacity.

One-dimensional biomass fast pyrolysis model with reaction kinetics integrated in an Aspen Plus Biorefinery Process Model

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

Humbird, David; Trendewicz, Anna; Braun, Robert

A biomass fast pyrolysis reactor model with detailed reaction kinetics and one-dimensional fluid dynamics was implemented in an equation-oriented modeling environment (Aspen Custom Modeler). Portions of this work were detailed in previous publications; further modifications have been made here to improve stability and reduce execution time of the model to make it compatible for use in large process flowsheets. The detailed reactor model was integrated into a larger process simulation in Aspen Plus and was stable for different feedstocks over a range of reactor temperatures. Sample results are presented that indicate general agreement with experimental results, but with higher gasmore » losses caused by stripping of the bio-oil by the fluidizing gas in the simulated absorber/condenser. Lastly, this integrated modeling approach can be extended to other well-defined, predictive reactor models for fast pyrolysis, catalytic fast pyrolysis, as well as other processes.« less

48 CFR 13.403 - Preparation and execution of orders.

Code of Federal Regulations, 2012 CFR

2012-10-01

... REGULATION CONTRACTING METHODS AND CONTRACT TYPES SIMPLIFIED ACQUISITION PROCEDURES Fast Payment Procedure 13... the fast payment procedure shall include the following: (a) A requirement that the supplies be shipped...

48 CFR 13.403 - Preparation and execution of orders.

Code of Federal Regulations, 2011 CFR

2011-10-01

... REGULATION CONTRACTING METHODS AND CONTRACT TYPES SIMPLIFIED ACQUISITION PROCEDURES Fast Payment Procedure 13... the fast payment procedure shall include the following: (a) A requirement that the supplies be shipped...

48 CFR 13.403 - Preparation and execution of orders.

Code of Federal Regulations, 2014 CFR

2014-10-01

... REGULATION CONTRACTING METHODS AND CONTRACT TYPES SIMPLIFIED ACQUISITION PROCEDURES Fast Payment Procedure 13... the fast payment procedure shall include the following: (a) A requirement that the supplies be shipped...

48 CFR 13.403 - Preparation and execution of orders.

Code of Federal Regulations, 2010 CFR

2010-10-01

... REGULATION CONTRACTING METHODS AND CONTRACT TYPES SIMPLIFIED ACQUISITION PROCEDURES Fast Payment Procedure 13... the fast payment procedure shall include the following: (a) A requirement that the supplies be shipped...

48 CFR 13.403 - Preparation and execution of orders.

Code of Federal Regulations, 2013 CFR

2013-10-01

... REGULATION CONTRACTING METHODS AND CONTRACT TYPES SIMPLIFIED ACQUISITION PROCEDURES Fast Payment Procedure 13... the fast payment procedure shall include the following: (a) A requirement that the supplies be shipped...

Voluntary stepping behavior under single- and dual-task conditions in chronic stroke survivors: A comparison between the involved and uninvolved legs.

PubMed

Melzer, Itshak; Goldring, Melissa; Melzer, Yehudit; Green, Elad; Tzedek, Irit

2010-12-01

If balance is lost, quick step execution can prevent falls. Research has shown that speed of voluntary stepping was able to predict future falls in old adults. The aim of the study was to investigate voluntary stepping behavior, as well as to compare timing and leg push-off force-time relation parameters of involved and uninvolved legs in stroke survivors during single- and dual-task conditions. We also aimed to compare timing and leg push-off force-time relation parameters between stroke survivors and healthy individuals in both task conditions. Ten stroke survivors performed a voluntary step execution test with their involved and uninvolved legs under two conditions: while focusing only on the stepping task and while a separate attention-demanding task was performed simultaneously. Temporal parameters related to the step time were measured including the duration of the step initiation phase, the preparatory phase, the swing phase, and the total step time. In addition, force-time parameters representing the push-off power during stepping were calculated from ground reaction data and compared with 10 healthy controls. The involved legs of stroke survivors had a significantly slower stepping time than uninvolved legs due to increased swing phase duration during both single- and dual-task conditions. For dual compared to single task, the stepping time increased significantly due to a significant increase in the duration of step initiation. In general, the force time parameters were significantly different in both legs of stroke survivors as compared to healthy controls, with no significant effect of dual compared with single-task conditions in both groups. The inability of stroke survivors to swing the involved leg quickly may be the most significant factor contributing to the large number of falls to the paretic side. The results suggest that stroke survivors were unable to rapidly produce muscle force in fast actions. This may be the mechanism of delayed execution of a fast step when balance is lost, thus increasing the likelihood of falls in stroke survivors. Copyright © 2010 Elsevier Ltd. All rights reserved.

A fast and reliable method for daily quality assurance in spot scanning proton therapy with a compact and inexpensive phantom.

PubMed

Bizzocchi, Nicola; Fracchiolla, Francesco; Schwarz, Marco; Algranati, Carlo

2017-01-01

In a radiotherapy center, daily quality assurance (QA) measurements are performed to ensure that the equipment can be safely used for patient treatment on that day. In a pencil beam scanning (PBS) proton therapy center, spot positioning, spot size, range, and dose output are usually verified every day before treatments. We designed, built, and tested a new, reliable, sensitive, and inexpensive phantom, coupled with an array of ionization chambers, for daily QA that reduces the execution times while preserving the reliability of the test. The phantom is provided with 2 pairs of wedges to sample the Bragg peak at different depths to have a transposition on the transverse plane of the depth dose. Three "boxes" are used to check spot positioning and delivered dose. The box thickness helps spread the single spot and to fit a Gaussian profile on a low resolution detector. We tested whether our new QA solution could detect errors larger than our action levels: 1 mm in spot positioning, 2 mm in range, and 10% in spot size. Execution time was also investigated. Our method is able to correctly detect 98% of spots that are actually in tolerance for spot positioning and 99% of spots out of 1 mm tolerance. All range variations greater than the threshold (2 mm) were correctly detected. The analysis performed over 1 month showed a very good repeatability of spot characteristics. The time taken to perform the daily quality assurance is 20 minutes, a half of the execution time of the former multidevice procedure. This "in-house build" phantom substitutes 2 very expensive detectors (a multilayer ionization chamber [MLIC] and a strip chamber, reducing by 5 times the cost of the equipment. We designed, built, and validated a phantom that allows for accurate, sensitive, fast, and inexpensive daily QA procedures in proton therapy with PBS. Copyright © 2017 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

Mental Rotation of Tactical Instruction Displays Affects Information Processing Demand and Execution Accuracy in Basketball

ERIC Educational Resources Information Center

Koopmann, Till; Steggemann-Weinrich, Yvonne; Baumeister, Jochen; Krause, Daniel

2017-01-01

Purpose: In sports games, coaches often use tactic boards to present tactical instructions during time-outs (e.g., 20 s to 60 s in basketball). Instructions should be presented in a way that enables fast and errorless information processing for the players. The aim of this study was to test the effect of different orientations of visual tactical…

Fast Ss-Ilm a Computationally Efficient Algorithm to Discover Socially Important Locations

NASA Astrophysics Data System (ADS)

Dokuz, A. S.; Celik, M.

2017-11-01

Socially important locations are places which are frequently visited by social media users in their social media lifetime. Discovering socially important locations provide several valuable information about user behaviours on social media networking sites. However, discovering socially important locations are challenging due to data volume and dimensions, spatial and temporal calculations, location sparseness in social media datasets, and inefficiency of current algorithms. In the literature, several studies are conducted to discover important locations, however, the proposed approaches do not work in computationally efficient manner. In this study, we propose Fast SS-ILM algorithm by modifying the algorithm of SS-ILM to mine socially important locations efficiently. Experimental results show that proposed Fast SS-ILM algorithm decreases execution time of socially important locations discovery process up to 20 %.

Personal Computer and Workstation Operating Systems Tutorial

DTIC Science & Technology

1994-03-01

to a RAM area where it is executed by the CPU. The program consists of instructions that perform operations on data. The CPU will perform two basic...memory to improve system performance. More often the user will buy a new fixed disk so the computer will hold more programs internally. The trend today...MHZ. Another way to view how fast the information is going into the register is in a time domain rather than a frequency domain knowing that time and

[Spanish translation and validation of an Executive Battery 25 (EB25) and its shortened version (ABE12) for executive dysfunction screening in dementia].

PubMed

Serrani Azcurra, D J L

2013-10-01

There is a need for clinically administered instruments capable of detecting executive dysfunction in dementia. The translation and validation of Executive Battery 25 (EB25) and a short version for screening of executive dysfunction in dementia. The original battery was translated and validated using convergent and divergent correlation in 66 mild dementia patients (CDR 1) matched with 66 controls. EB25 consists of 25 items which detect executive dysfunction. Convergent correlation was made with 7 tests assessing executive dysfunction, the Frontal Systems Behaviour Scale (FrSBe) and Disability Fast Assessment Scale. Patients had higher scores than controls and correlated with the Stroop Test, verbal fluency test and Frontal Behaviour Inventory. Only 12 out of 25 items were needed to separate both groups, which were used to build an abbreviated Executive Battery with equal psychometric properties and discriminative power. The cut-off point for EB25 was 12, and 7 for the abbreviated version. A cut-off point of 12 was able to discriminate between ¿Alzheimer's disease? (AD) and frontotemporal lobe dementia (FTLD). EB25 and AEB12 enable executive dysfunction to be detected in mild dementia. On the other hand, AEB12 exhibits better psychometric properties than the original battery, allowing discrimination between AD and FTLD and is completed in less time. Copyright © 2010 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

Determinants of the effectiveness of fast break actions in elite and sub-elite Italian men’s basketball games

PubMed Central

Favero, TG; Niederhausen, M; Capranica, L; Tessitore, A

2017-01-01

The aim of this study was to examine the determinants of successful and unsuccessful fast-break (FB) actions in elite and sub-elite basketball games. Fifteen 1st-division (elite) and fifteen 3rd-division (sub-elite) Italian men’s championship games were analysed across two seasons (2012/2013 and 2013/2014). A binary logistic regression analysis was performed, and the fast-break outcome (successful vs. unsuccessful) was adopted as the dependent variable separately in both elite and sub-elite games. FB execution (initiation, advance and completion phases), typology (primary and secondary break) and the number of players involved (equal number or superiority) were used as independent variables. The results showed that the rate of success of FB actions was 63.5% and 59.7% in elite and sub-elite games, respectively. Moreover, successful FBs were more likely to be completed in the lane in relation to unsuccessful ones in both elite and sub-elite games (p<0.05). Finally, descriptive statistics showed that both elite and sub-elite teams executed FBs similarly. This study highlighted that completion zone was the only predictor of a successful fast break in basketball, while the typology and number of players involved did not predict fast break effectiveness. Moreover, elite and sub-elite teams executed fast break actions similarly. These findings might be useful for basketball coaches to optimize the training of FB actions. PMID:28566812

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

A fast reconstruction algorithm for fluorescence optical diffusion tomography based on preiteration.

PubMed

Song, Xiaolei; Xiong, Xiaoyun; Bai, Jing

2007-01-01

Fluorescence optical diffusion tomography in the near-infrared (NIR) bandwidth is considered to be one of the most promising ways for noninvasive molecular-based imaging. Many reconstructive approaches to it utilize iterative methods for data inversion. However, they are time-consuming and they are far from meeting the real-time imaging demands. In this work, a fast preiteration algorithm based on the generalized inverse matrix is proposed. This method needs only one step of matrix-vector multiplication online, by pushing the iteration process to be executed offline. In the preiteration process, the second-order iterative format is employed to exponentially accelerate the convergence. Simulations based on an analytical diffusion model show that the distribution of fluorescent yield can be well estimated by this algorithm and the reconstructed speed is remarkably increased.

A UNIX-based real-time data acquisition system for microprobe analysis using an advanced X11 window toolkit

NASA Astrophysics Data System (ADS)

Kramer, J. L. A. M.; Ullings, A. H.; Vis, R. D.

1993-05-01

A real-time data acquisition system for microprobe analysis has been developed at the Free University of Amsterdam. The system is composed of two parts: a front-end real-time and a back-end monitoring system. The front-end consists of a VMEbus based system which reads out a CAMAC crate. The back-end is implemented on a Sun work station running the UNIX operating system. This separation allows the integration of a minimal, and consequently very fast, real-time executive within the sophisticated possibilities of advanced UNIX work stations.

FAST: A fully asynchronous and status-tracking pattern for geoprocessing services orchestration

NASA Astrophysics Data System (ADS)

Wu, Huayi; You, Lan; Gui, Zhipeng; Gao, Shuang; Li, Zhenqiang; Yu, Jingmin

2014-09-01

Geoprocessing service orchestration (GSO) provides a unified and flexible way to implement cross-application, long-lived, and multi-step geoprocessing service workflows by coordinating geoprocessing services collaboratively. Usually, geoprocessing services and geoprocessing service workflows are data and/or computing intensive. The intensity feature may make the execution process of a workflow time-consuming. Since it initials an execution request without blocking other interactions on the client side, an asynchronous mechanism is especially appropriate for GSO workflows. Many critical problems remain to be solved in existing asynchronous patterns for GSO including difficulties in improving performance, status tracking, and clarifying the workflow structure. These problems are a challenge when orchestrating performance efficiency, making statuses instantly available, and constructing clearly structured GSO workflows. A Fully Asynchronous and Status-Tracking (FAST) pattern that adopts asynchronous interactions throughout the whole communication tier of a workflow is proposed for GSO. The proposed FAST pattern includes a mechanism that actively pushes the latest status to clients instantly and economically. An independent proxy was designed to isolate the status tracking logic from the geoprocessing business logic, which assists the formation of a clear GSO workflow structure. A workflow was implemented in the FAST pattern to simulate the flooding process in the Poyang Lake region. Experimental results show that the proposed FAST pattern can efficiently tackle data/computing intensive geoprocessing tasks. The performance of all collaborative partners was improved due to the asynchronous mechanism throughout communication tier. A status-tracking mechanism helps users retrieve the latest running status of a GSO workflow in an efficient and instant way. The clear structure of the GSO workflow lowers the barriers for geospatial domain experts and model designers to compose asynchronous GSO workflows. Most importantly, it provides better support for locating and diagnosing potential exceptions.

High-Frequency Replanning Under Uncertainty Using Parallel Sampling-Based Motion Planning

PubMed Central

Sun, Wen; Patil, Sachin; Alterovitz, Ron

2015-01-01

As sampling-based motion planners become faster, they can be re-executed more frequently by a robot during task execution to react to uncertainty in robot motion, obstacle motion, sensing noise, and uncertainty in the robot’s kinematic model. We investigate and analyze high-frequency replanning (HFR), where, during each period, fast sampling-based motion planners are executed in parallel as the robot simultaneously executes the first action of the best motion plan from the previous period. We consider discrete-time systems with stochastic nonlinear (but linearizable) dynamics and observation models with noise drawn from zero mean Gaussian distributions. The objective is to maximize the probability of success (i.e., avoid collision with obstacles and reach the goal) or to minimize path length subject to a lower bound on the probability of success. We show that, as parallel computation power increases, HFR offers asymptotic optimality for these objectives during each period for goal-oriented problems. We then demonstrate the effectiveness of HFR for holonomic and nonholonomic robots including car-like vehicles and steerable medical needles. PMID:26279645

Adaptive Monocular Visual-Inertial SLAM for Real-Time Augmented Reality Applications in Mobile Devices.

PubMed

Piao, Jin-Chun; Kim, Shin-Dug

2017-11-07

Simultaneous localization and mapping (SLAM) is emerging as a prominent issue in computer vision and next-generation core technology for robots, autonomous navigation and augmented reality. In augmented reality applications, fast camera pose estimation and true scale are important. In this paper, we present an adaptive monocular visual-inertial SLAM method for real-time augmented reality applications in mobile devices. First, the SLAM system is implemented based on the visual-inertial odometry method that combines data from a mobile device camera and inertial measurement unit sensor. Second, we present an optical-flow-based fast visual odometry method for real-time camera pose estimation. Finally, an adaptive monocular visual-inertial SLAM is implemented by presenting an adaptive execution module that dynamically selects visual-inertial odometry or optical-flow-based fast visual odometry. Experimental results show that the average translation root-mean-square error of keyframe trajectory is approximately 0.0617 m with the EuRoC dataset. The average tracking time is reduced by 7.8%, 12.9%, and 18.8% when different level-set adaptive policies are applied. Moreover, we conducted experiments with real mobile device sensors, and the results demonstrate the effectiveness of performance improvement using the proposed method.

Facilitating Goal-Oriented Behaviour in the Stroop Task: When Executive Control Is Influenced by Automatic Processing

PubMed Central

Parris, Benjamin A.; Bate, Sarah; Brown, Scott D.; Hodgson, Timothy L.

2012-01-01

A portion of Stroop interference is thought to arise from a failure to maintain goal-oriented behaviour (or goal neglect). The aim of the present study was to investigate whether goal- relevant primes could enhance goal maintenance and reduce the Stroop interference effect. Here it is shown that primes related to the goal of responding quickly in the Stroop task (e.g. fast, quick, hurry) substantially reduced Stroop interference by reducing reaction times to incongruent trials but increasing reaction times to congruent and neutral trials. No effects of the primes were observed on errors. The effects on incongruent, congruent and neutral trials are explained in terms of the influence of the primes on goal maintenance. The results show that goal priming can facilitate goal-oriented behaviour and indicate that automatic processing can modulate executive control. PMID:23056553

Cortical Specializations Underlying Fast Computations

PubMed Central

Volgushev, Maxim

2016-01-01

The time course of behaviorally relevant environmental events sets temporal constraints on neuronal processing. How does the mammalian brain make use of the increasingly complex networks of the neocortex, while making decisions and executing behavioral reactions within a reasonable time? The key parameter determining the speed of computations in neuronal networks is a time interval that neuronal ensembles need to process changes at their input and communicate results of this processing to downstream neurons. Theoretical analysis identified basic requirements for fast processing: use of neuronal populations for encoding, background activity, and fast onset dynamics of action potentials in neurons. Experimental evidence shows that populations of neocortical neurons fulfil these requirements. Indeed, they can change firing rate in response to input perturbations very quickly, within 1 to 3 ms, and encode high-frequency components of the input by phase-locking their spiking to frequencies up to 300 to 1000 Hz. This implies that time unit of computations by cortical ensembles is only few, 1 to 3 ms, which is considerably faster than the membrane time constant of individual neurons. The ability of cortical neuronal ensembles to communicate on a millisecond time scale allows for complex, multiple-step processing and precise coordination of neuronal activity in parallel processing streams, while keeping the speed of behavioral reactions within environmentally set temporal constraints. PMID:25689988

Real time processor for array speckle interferometry

NASA Astrophysics Data System (ADS)

Chin, Gordon; Florez, Jose; Borelli, Renan; Fong, Wai; Miko, Joseph; Trujillo, Carlos

1989-02-01

The authors are constructing a real-time processor to acquire image frames, perform array flat-fielding, execute a 64 x 64 element two-dimensional complex FFT (fast Fourier transform) and average the power spectrum, all within the 25 ms coherence time for speckles at near-IR (infrared) wavelength. The processor will be a compact unit controlled by a PC with real-time display and data storage capability. This will provide the ability to optimize observations and obtain results on the telescope rather than waiting several weeks before the data can be analyzed and viewed with offline methods. The image acquisition and processing, design criteria, and processor architecture are described.

Real time processor for array speckle interferometry

NASA Technical Reports Server (NTRS)

Chin, Gordon; Florez, Jose; Borelli, Renan; Fong, Wai; Miko, Joseph; Trujillo, Carlos

1989-01-01

The authors are constructing a real-time processor to acquire image frames, perform array flat-fielding, execute a 64 x 64 element two-dimensional complex FFT (fast Fourier transform) and average the power spectrum, all within the 25 ms coherence time for speckles at near-IR (infrared) wavelength. The processor will be a compact unit controlled by a PC with real-time display and data storage capability. This will provide the ability to optimize observations and obtain results on the telescope rather than waiting several weeks before the data can be analyzed and viewed with offline methods. The image acquisition and processing, design criteria, and processor architecture are described.

A systematic review of the effects of experimental fasting on cognition.

PubMed

Benau, Erik M; Orloff, Natalia C; Janke, E Amy; Serpell, Lucy; Timko, C Alix

2014-06-01

Numerous investigations have been conducted on the impact of short-term fasting on cognition in healthy individuals. Some studies have suggested that fasting is associated with executive function deficits; however, findings have been inconsistent. The lack of consensus regarding the impact of short-term fasting in healthy controls has impeded investigation of the impact of starvation or malnutrition in clinical groups, such as anorexia nervosa (AN). One method of disentangling these effects is to examine acute episodes of starvation experimentally. The present review systematically investigated the impact of short-term fasting on cognition. Studies investigating attentional bias to food-related stimuli were excluded so as to focus on general cognition. Ten articles were included in the review. The combined results are equivocal: several studies report no observable differences as a result of fasting and others show specific deficits on tasks designed to test psychomotor speed, executive function, and mental rotation. This inconsistent profile of fasting in healthy individuals demonstrates the complexity of the role of short-term fasting in cognition; the variety of tasks used, composition of the sample, and type and duration of fasting across studies may also have contributed to the inconsistent profile. Additional focused studies on neuropsychological profiles of healthy individuals are warranted in order to better develop an understanding of the role of hunger in cognition. Copyright © 2014 Elsevier Ltd. All rights reserved.

Reconstruction of shifting elbow joint compliant characteristics during fast and slow movements.

PubMed

Latash, M L; Gottlieb, G L

1991-01-01

The purpose of this study was to experimentally investigate the applicability of the equilibrium-point hypothesis to the dynamics of single-joint movements. Subjects were trained to perform relatively slow (movement time 600-1000 ms) or fast (movement time 200-300 ms) single-joint elbow flexion movements against a constant extending torque bias. They were instructed to reproduce the same time pattern of central motor command for a series of movements when the external torque could slowly and unpredictably increase, decrease, or remain constant. For fast movements, the total muscle torque was calculated as a sum of external and inertial components. Analysis of the data allowed reconstruction of the elbow joint compliant characteristics at different times during execution of the learned motor command. "Virtual" trajectories of the movements, representing time-varying changes in a central control parameter, were reconstructed and compared with the "actual" trajectories. For slow movements, the actual trajectories lagged behind the virtual ones. There were no consistent changes in the joint stiffness during slow movements. Similar analysis of experiments without voluntary movements demonstrated a lack of changes in the central parameters, supporting the assumption that the subjects were able to keep the same central motor command in spite of externally imposed unexpected torque perturbations. For the fast movements, the virtual trajectories were N-shaped, and the joint stiffness demonstrated a considerable increase near the middle of the movement. These findings contradict an hypothesis of monotonic joint compliant characteristic translation at a nearly constant rate during such movements.

Specific Early Number Skills Mediate the Association between Executive Functioning Skills and Mathematics Achievement

ERIC Educational Resources Information Center

Fuhs, Mary Wagner; Hornburg, Caroline Byrd; McNeil, Nicole M.

2016-01-01

A growing literature reports significant associations between children's executive functioning skills and their mathematics achievement. The purpose of this study was to examine if specific early number skills, such as quantity discrimination, number line estimation, number sets identification, fast counting, and number word comprehension, mediate…

Compute-unified device architecture implementation of a block-matching algorithm for multiple graphical processing unit cards

PubMed Central

Massanes, Francesc; Cadennes, Marie; Brankov, Jovan G.

2012-01-01

In this paper we describe and evaluate a fast implementation of a classical block matching motion estimation algorithm for multiple Graphical Processing Units (GPUs) using the Compute Unified Device Architecture (CUDA) computing engine. The implemented block matching algorithm (BMA) uses summed absolute difference (SAD) error criterion and full grid search (FS) for finding optimal block displacement. In this evaluation we compared the execution time of a GPU and CPU implementation for images of various sizes, using integer and non-integer search grids. The results show that use of a GPU card can shorten computation time by a factor of 200 times for integer and 1000 times for a non-integer search grid. The additional speedup for non-integer search grid comes from the fact that GPU has built-in hardware for image interpolation. Further, when using multiple GPU cards, the presented evaluation shows the importance of the data splitting method across multiple cards, but an almost linear speedup with a number of cards is achievable. In addition we compared execution time of the proposed FS GPU implementation with two existing, highly optimized non-full grid search CPU based motion estimations methods, namely implementation of the Pyramidal Lucas Kanade Optical flow algorithm in OpenCV and Simplified Unsymmetrical multi-Hexagon search in H.264/AVC standard. In these comparisons, FS GPU implementation still showed modest improvement even though the computational complexity of FS GPU implementation is substantially higher than non-FS CPU implementation. We also demonstrated that for an image sequence of 720×480 pixels in resolution, commonly used in video surveillance, the proposed GPU implementation is sufficiently fast for real-time motion estimation at 30 frames-per-second using two NVIDIA C1060 Tesla GPU cards. PMID:22347787

Compute-unified device architecture implementation of a block-matching algorithm for multiple graphical processing unit cards.

PubMed

Massanes, Francesc; Cadennes, Marie; Brankov, Jovan G

2011-07-01

In this paper we describe and evaluate a fast implementation of a classical block matching motion estimation algorithm for multiple Graphical Processing Units (GPUs) using the Compute Unified Device Architecture (CUDA) computing engine. The implemented block matching algorithm (BMA) uses summed absolute difference (SAD) error criterion and full grid search (FS) for finding optimal block displacement. In this evaluation we compared the execution time of a GPU and CPU implementation for images of various sizes, using integer and non-integer search grids.The results show that use of a GPU card can shorten computation time by a factor of 200 times for integer and 1000 times for a non-integer search grid. The additional speedup for non-integer search grid comes from the fact that GPU has built-in hardware for image interpolation. Further, when using multiple GPU cards, the presented evaluation shows the importance of the data splitting method across multiple cards, but an almost linear speedup with a number of cards is achievable.In addition we compared execution time of the proposed FS GPU implementation with two existing, highly optimized non-full grid search CPU based motion estimations methods, namely implementation of the Pyramidal Lucas Kanade Optical flow algorithm in OpenCV and Simplified Unsymmetrical multi-Hexagon search in H.264/AVC standard. In these comparisons, FS GPU implementation still showed modest improvement even though the computational complexity of FS GPU implementation is substantially higher than non-FS CPU implementation.We also demonstrated that for an image sequence of 720×480 pixels in resolution, commonly used in video surveillance, the proposed GPU implementation is sufficiently fast for real-time motion estimation at 30 frames-per-second using two NVIDIA C1060 Tesla GPU cards.

Execution of saccadic eye movements affects speed perception

PubMed Central

Goettker, Alexander; Braun, Doris I.; Schütz, Alexander C.; Gegenfurtner, Karl R.

2018-01-01

Due to the foveal organization of our visual system we have to constantly move our eyes to gain precise information about our environment. Doing so massively alters the retinal input. This is problematic for the perception of moving objects, because physical motion and retinal motion become decoupled and the brain has to discount the eye movements to recover the speed of moving objects. Two different types of eye movements, pursuit and saccades, are combined for tracking. We investigated how the way we track moving targets can affect the perceived target speed. We found that the execution of corrective saccades during pursuit initiation modifies how fast the target is perceived compared with pure pursuit. When participants executed a forward (catch-up) saccade they perceived the target to be moving faster. When they executed a backward saccade they perceived the target to be moving more slowly. Variations in pursuit velocity without corrective saccades did not affect perceptual judgments. We present a model for these effects, assuming that the eye velocity signal for small corrective saccades gets integrated with the retinal velocity signal during pursuit. In our model, the execution of corrective saccades modulates the integration of these two signals by giving less weight to the retinal information around the time of corrective saccades. PMID:29440494

Fast algorithm for automatically computing Strahler stream order

USGS Publications Warehouse

Lanfear, Kenneth J.

1990-01-01

An efficient algorithm was developed to determine Strahler stream order for segments of stream networks represented in a Geographic Information System (GIS). The algorithm correctly assigns Strahler stream order in topologically complex situations such as braided streams and multiple drainage outlets. Execution time varies nearly linearly with the number of stream segments in the network. This technique is expected to be particularly useful for studying the topology of dense stream networks derived from digital elevation model data.

An equilibrium-point model for fast, single-joint movement: I. Emergence of strategy-dependent EMG patterns.

PubMed

Latash, M L; Gottlieb, G L

1991-09-01

We describe a model for the regulation of fast, single-joint movements, based on the equilibrium-point hypothesis. Limb movement follows constant rate shifts of independently regulated neuromuscular variables. The independently regulated variables are tentatively identified as thresholds of a length sensitive reflex for each of the participating muscles. We use the model to predict EMG patterns associated with changes in the conditions of movement execution, specifically, changes in movement times, velocities, amplitudes, and moments of limb inertia. The approach provides a theoretical neural framework for the dual-strategy hypothesis, which considers certain movements to be results of one of two basic, speed-sensitive or speed-insensitive strategies. This model is advanced as an alternative to pattern-imposing models based on explicit regulation of timing and amplitudes of signals that are explicitly manifest in the EMG patterns.

Associations between Markers of Glucose and Insulin Function and Cognitive Function in Healthy African American Elders

PubMed Central

Skinner, Jeannine S.; Morgan, Amy; Hernandez-Saucedo, Hector; Hansen, Angela; Corbett, Selena; Arbuckle, Matthew; Leverenz, James BA; Wilkins, Consuelo H.; Craft, Suzanne; Baker, Laura D.

2015-01-01

Background Glucose and insulin are important moderators of cognitive function. African Americans have poorer glycemic control across the glycemic spectrum and are at increased risk for type 2 diabetes and poor cognitive health. It is unclear which glucoregulatory markers predict cognitive function in this at-risk population. The purpose of this study was to examine the association between cognitive function and common markers of glucoregulation in non-diabetic African Americans elders. Methods Thirty-four, community-dwelling African Americans, aged 50-75 years completed cognitive testing and blood collection as part of a health screening assessment. Cognitive outcomes were composite scores derived from neuropsychological tests of executive function and verbal memory. Linear regression was used to examine relationships between cognitive composite scores and fasting blood levels of glucose, insulin, and hemoglobin A1C, with adjustments for age, education, body mass index, and antihypertensive medication use. Results Fasting plasma glucose was negatively associated with executive function (β=−0.41, p=0.03). There was a trend of an association between fasting plasma glucose and verbal memory (β=−0.34, p=0.06). Fasting insulin and hemoglobin A1c were not associated with cognitive function. Conclusion High non-diabetic fasting glucose levels were associated with poorer executive function and verbal memory. These results provide preliminary support for proactive glucose control in older African Americans even before glycemic criteria for type 2 diabetes are met. Our findings suggests that high-normal FPG levels may represent an early red-flag to signify increased risk of cognitive impairment or decline. PMID:26798567

Adaptive Monocular Visual–Inertial SLAM for Real-Time Augmented Reality Applications in Mobile Devices

PubMed Central

Piao, Jin-Chun; Kim, Shin-Dug

2017-01-01

Simultaneous localization and mapping (SLAM) is emerging as a prominent issue in computer vision and next-generation core technology for robots, autonomous navigation and augmented reality. In augmented reality applications, fast camera pose estimation and true scale are important. In this paper, we present an adaptive monocular visual–inertial SLAM method for real-time augmented reality applications in mobile devices. First, the SLAM system is implemented based on the visual–inertial odometry method that combines data from a mobile device camera and inertial measurement unit sensor. Second, we present an optical-flow-based fast visual odometry method for real-time camera pose estimation. Finally, an adaptive monocular visual–inertial SLAM is implemented by presenting an adaptive execution module that dynamically selects visual–inertial odometry or optical-flow-based fast visual odometry. Experimental results show that the average translation root-mean-square error of keyframe trajectory is approximately 0.0617 m with the EuRoC dataset. The average tracking time is reduced by 7.8%, 12.9%, and 18.8% when different level-set adaptive policies are applied. Moreover, we conducted experiments with real mobile device sensors, and the results demonstrate the effectiveness of performance improvement using the proposed method. PMID:29112143

Topography of Slow Sigma Power during Sleep is Associated with Processing Speed in Preschool Children.

PubMed

Doucette, Margaret R; Kurth, Salome; Chevalier, Nicolas; Munakata, Yuko; LeBourgeois, Monique K

2015-11-04

Cognitive development is influenced by maturational changes in processing speed, a construct reflecting the rapidity of executing cognitive operations. Although cognitive ability and processing speed are linked to spindles and sigma power in the sleep electroencephalogram (EEG), little is known about such associations in early childhood, a time of major neuronal refinement. We calculated EEG power for slow (10-13 Hz) and fast (13.25-17 Hz) sigma power from all-night high-density electroencephalography (EEG) in a cross-sectional sample of healthy preschool children (n = 10, 4.3 ± 1.0 years). Processing speed was assessed as simple reaction time. On average, reaction time was 1409 ± 251 ms; slow sigma power was 4.0 ± 1.5 μV²; and fast sigma power was 0.9 ± 0.2 μV². Both slow and fast sigma power predominated over central areas. Only slow sigma power was correlated with processing speed in a large parietal electrode cluster (p < 0.05, r ranging from -0.6 to -0.8), such that greater power predicted faster reaction time. Our findings indicate regional correlates between sigma power and processing speed that are specific to early childhood and provide novel insights into the neurobiological features of the EEG that may underlie developing cognitive abilities.

Feasibility study, software design, layout and simulation of a two-dimensional Fast Fourier Transform machine for use in optical array interferometry

NASA Technical Reports Server (NTRS)

Boriakoff, Valentin

1994-01-01

The goal of this project was the feasibility study of a particular architecture of a digital signal processing machine operating in real time which could do in a pipeline fashion the computation of the fast Fourier transform (FFT) of a time-domain sampled complex digital data stream. The particular architecture makes use of simple identical processors (called inner product processors) in a linear organization called a systolic array. Through computer simulation the new architecture to compute the FFT with systolic arrays was proved to be viable, and computed the FFT correctly and with the predicted particulars of operation. Integrated circuits to compute the operations expected of the vital node of the systolic architecture were proven feasible, and even with a 2 micron VLSI technology can execute the required operations in the required time. Actual construction of the integrated circuits was successful in one variant (fixed point) and unsuccessful in the other (floating point).

Exact numerical calculation of fixation probability and time on graphs.

PubMed

Hindersin, Laura; Möller, Marius; Traulsen, Arne; Bauer, Benedikt

2016-12-01

The Moran process on graphs is a popular model to study the dynamics of evolution in a spatially structured population. Exact analytical solutions for the fixation probability and time of a new mutant have been found for only a few classes of graphs so far. Simulations are time-expensive and many realizations are necessary, as the variance of the fixation times is high. We present an algorithm that numerically computes these quantities for arbitrary small graphs by an approach based on the transition matrix. The advantage over simulations is that the calculation has to be executed only once. Building the transition matrix is automated by our algorithm. This enables a fast and interactive study of different graph structures and their effect on fixation probability and time. We provide a fast implementation in C with this note (Hindersin et al., 2016). Our code is very flexible, as it can handle two different update mechanisms (Birth-death or death-Birth), as well as arbitrary directed or undirected graphs. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Fast Context Switching in Real-Time Propositional Reasoning

NASA Technical Reports Server (NTRS)

Nayak, P. Pandurang; Williams, Brian C.

1997-01-01

The trend to increasingly capable and affordable control processors has generated an explosion of embedded real-time gadgets that serve almost every function imaginable. The daunting task of programming these gadgets is greatly alleviated with real-time deductive engines that perform all execution and monitoring functions from a single core model, Fast response times are achieved using an incremental propositional deductive database (an LTMS). Ideally the cost of an LTMS's incremental update should be linear in the number of labels that change between successive contexts. Unfortunately an LTMS can expend a significant percentage of its time working on labels that remain constant between contexts. This is caused by the LTMS's conservative approach: a context switch first removes all consequences of deleted clauses, whether or not those consequences hold in the new context. This paper presents a more aggressive incremental TMS, called the ITMS, that avoids processing a significant number of these consequences that are unchanged. Our empirical evaluation for spacecraft control shows that the overhead of processing unchanged consequences can be reduced by a factor of seven.

Performance Characterization of Obstacle Detection Algorithms for Aircraft Navigation

NASA Technical Reports Server (NTRS)

Kasturi, Rangachar; Camps, Octavia; Coraor, Lee; Gandhi, Tarak; Hartman, Kerry; Yang, Mau-Tsuen

2000-01-01

The research reported here is a part of NASA's Synthetic Vision System (SVS) project for the development of a High Speed Civil Transport Aircraft (HSCT). One of the components of the SVS is a module for detection of potential obstacles in the aircraft's flight path by analyzing the images captured by an on-board camera in real-time. Design of such a module includes the selection and characterization of robust, reliable, and fast techniques and their implementation for execution in real-time. This report describes the results of our research in realizing such a design.

Manned and Unmanned Aircraft Effectiveness in Fast Attack Craft / Fast Inshore Attack Craft ASUW Kill Chain Execution

DTIC Science & Technology

2016-09-01

par. 4) Based on a RED projected size of 22.16 m, a sample calculation for the unadjusted single shot probability of kill for HELLFIRE missiles is...framework based on intelligent objects (SIMIO) environment to model a fast attack craft/fast inshore attack craft anti-surface warfare expanded kill chain...concept of operation efficiency. Based on the operational environment, low cost and less capable unmanned aircraft provide an alternative to the

Fast solution of elliptic partial differential equations using linear combinations of plane waves.

PubMed

Pérez-Jordá, José M

2016-02-01

Given an arbitrary elliptic partial differential equation (PDE), a procedure for obtaining its solution is proposed based on the method of Ritz: the solution is written as a linear combination of plane waves and the coefficients are obtained by variational minimization. The PDE to be solved is cast as a system of linear equations Ax=b, where the matrix A is not sparse, which prevents the straightforward application of standard iterative methods in order to solve it. This sparseness problem can be circumvented by means of a recursive bisection approach based on the fast Fourier transform, which makes it possible to implement fast versions of some stationary iterative methods (such as Gauss-Seidel) consuming O(NlogN) memory and executing an iteration in O(Nlog(2)N) time, N being the number of plane waves used. In a similar way, fast versions of Krylov subspace methods and multigrid methods can also be implemented. These procedures are tested on Poisson's equation expressed in adaptive coordinates. It is found that the best results are obtained with the GMRES method using a multigrid preconditioner with Gauss-Seidel relaxation steps.

Resources on Social and Emotional Development and Early Learning Standards. CEELO FastFacts

ERIC Educational Resources Information Center

Connors-Tadros, L.

2013-01-01

In this "FastFacts," a state's Department of Education requests information from the Center on Enhancing Early Learning Outcomes (CEELO) on how the research defines skills in social-emotional development, approaches to learning, and executive function, to inform planned revisions to the early childhood indicators of progress for children…

FastDart : a fast, accurate and friendly version of DART code.

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

Rest, J.; Taboada, H.

2000-11-08

A new enhanced, visual version of DART code is presented. DART is a mechanistic model based code, developed for the performance calculation and assessment of aluminum dispersion fuel. Major issues of this new version are the development of a new, time saving calculation routine, able to be run on PC, a friendly visual input interface and a plotting facility. This version, available for silicide and U-Mo fuels,adds to the classical accuracy of DART models for fuel performance prediction, a faster execution and visual interfaces. It is part of a collaboration agreement between ANL and CNEA in the area of Lowmore » Enriched Uranium Advanced Fuels, held by the Implementation Arrangement for Technical Exchange and Cooperation in the Area of Peaceful Uses of Nuclear Energy.« less

Music intervention as system: reversing hyper systemising in autism spectrum disorders to the comprehension of music as intervention.

PubMed

Jaschke, Artur C

2014-01-01

This paper seeks to combine the notion of the Empathising-Systemising (E-S) theory and the resulting twist from the executive dysfunction theory in autism spectrum conditions (ASC) in light of music intervention as system. To achieve these points it will be important to re-visit, nonetheless briefly, the above mentioned theories and re-define music intervention in the light of these. Furthermore there is the need to adjust the executive dysfunction theory to a theory of dysfunctioning executive functions. These notions will create a different understanding of music intervention in this context, allowing the development of future and existing music intervention programs applied clinically. These applications will evolve around a structuralised approach to music intervention as system, proposing five consecutive systems. It will therefore argue the aspects of expanding existing theories in ASC together with the call for generalised interventions to better assess autism from a theoretical point of view. Theories have to be updated in a time of fast and ever-changing development. Copyright © 2013 Elsevier Ltd. All rights reserved.

A pipeline VLSI design of fast singular value decomposition processor for real-time EEG system based on on-line recursive independent component analysis.

PubMed

Huang, Kuan-Ju; Shih, Wei-Yeh; Chang, Jui Chung; Feng, Chih Wei; Fang, Wai-Chi

2013-01-01

This paper presents a pipeline VLSI design of fast singular value decomposition (SVD) processor for real-time electroencephalography (EEG) system based on on-line recursive independent component analysis (ORICA). Since SVD is used frequently in computations of the real-time EEG system, a low-latency and high-accuracy SVD processor is essential. During the EEG system process, the proposed SVD processor aims to solve the diagonal, inverse and inverse square root matrices of the target matrices in real time. Generally, SVD requires a huge amount of computation in hardware implementation. Therefore, this work proposes a novel design concept for data flow updating to assist the pipeline VLSI implementation. The SVD processor can greatly improve the feasibility of real-time EEG system applications such as brain computer interfaces (BCIs). The proposed architecture is implemented using TSMC 90 nm CMOS technology. The sample rate of EEG raw data adopts 128 Hz. The core size of the SVD processor is 580×580 um(2), and the speed of operation frequency is 20MHz. It consumes 0.774mW of power during the 8-channel EEG system per execution time.

Learning fast accurate movements requires intact frontostriatal circuits

PubMed Central

Shabbott, Britne; Ravindran, Roshni; Schumacher, Joseph W.; Wasserman, Paula B.; Marder, Karen S.; Mazzoni, Pietro

2013-01-01

The basal ganglia are known to play a crucial role in movement execution, but their importance for motor skill learning remains unclear. Obstacles to our understanding include the lack of a universally accepted definition of motor skill learning (definition confound), and difficulties in distinguishing learning deficits from execution impairments (performance confound). We studied how healthy subjects and subjects with a basal ganglia disorder learn fast accurate reaching movements. We addressed the definition and performance confounds by: (1) focusing on an operationally defined core element of motor skill learning (speed-accuracy learning), and (2) using normal variation in initial performance to separate movement execution impairment from motor learning abnormalities. We measured motor skill learning as performance improvement in a reaching task with a speed-accuracy trade-off. We compared the performance of subjects with Huntington's disease (HD), a neurodegenerative basal ganglia disorder, to that of premanifest carriers of the HD mutation and of control subjects. The initial movements of HD subjects were less skilled (slower and/or less accurate) than those of control subjects. To factor out these differences in initial execution, we modeled the relationship between learning and baseline performance in control subjects. Subjects with HD exhibited a clear learning impairment that was not explained by differences in initial performance. These results support a role for the basal ganglia in both movement execution and motor skill learning. PMID:24312037

Topography of Slow Sigma Power during Sleep is Associated with Processing Speed in Preschool Children

PubMed Central

Doucette, Margaret R.; Kurth, Salome; Chevalier, Nicolas; Munakata, Yuko; LeBourgeois, Monique K.

2015-01-01

Cognitive development is influenced by maturational changes in processing speed, a construct reflecting the rapidity of executing cognitive operations. Although cognitive ability and processing speed are linked to spindles and sigma power in the sleep electroencephalogram (EEG), little is known about such associations in early childhood, a time of major neuronal refinement. We calculated EEG power for slow (10–13 Hz) and fast (13.25–17 Hz) sigma power from all-night high-density electroencephalography (EEG) in a cross-sectional sample of healthy preschool children (n = 10, 4.3 ± 1.0 years). Processing speed was assessed as simple reaction time. On average, reaction time was 1409 ± 251 ms; slow sigma power was 4.0 ± 1.5 μV2; and fast sigma power was 0.9 ± 0.2 μV2. Both slow and fast sigma power predominated over central areas. Only slow sigma power was correlated with processing speed in a large parietal electrode cluster (p < 0.05, r ranging from −0.6 to −0.8), such that greater power predicted faster reaction time. Our findings indicate regional correlates between sigma power and processing speed that are specific to early childhood and provide novel insights into the neurobiological features of the EEG that may underlie developing cognitive abilities. PMID:26556377

When music tempo affects the temporal congruence between physical practice and motor imagery.

PubMed

Debarnot, Ursula; Guillot, Aymeric

2014-06-01

When people listen to music, they hear beat and a metrical structure in the rhythm; these perceived patterns enable coordination with the music. A clear correspondence between the tempo of actual movement (e.g., walking) and that of music has been demonstrated, but whether similar coordination occurs during motor imagery is unknown. Twenty participants walked naturally for 8m, either physically or mentally, while listening to slow and fast music, or not listening to anything at all (control condition). Executed and imagined walking times were recorded to assess the temporal congruence between physical practice (PP) and motor imagery (MI). Results showed a difference when comparing slow and fast time conditions, but each of these durations did not differ from soundless condition times, hence showing that body movement may not necessarily change in order to synchronize with music. However, the main finding revealed that the ability to achieve temporal congruence between PP and MI times was altered when listening to either slow or fast music. These data suggest that when physical movement is modulated with respect to the musical tempo, the MI efficacy of the corresponding movement may be affected by the rhythm of the music. Practical applications in sport are discussed as athletes frequently listen to music before competing while they mentally practice their movements to be performed. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of Fasting During Ramadan Month on Cognitive Function in Muslim Athletes

PubMed Central

Tian, Ho-Heng; Aziz, Abdul-Rashid; Png, Weileen; Wahid, Mohamed Faizul; Yeo, Donald; Constance Png, Ai-Li

2011-01-01

Purpose Our study aimed to profile the effect of fasting during the Ramadan month on cognitive function in a group of healthy Muslim athletes. Methods Eighteen male athletes underwent computerized neuropsychological testing during (fasting) and after (non-fasting) Ramadan. Diet was standardized, and tests were performed at 0900h and 1600h to characterize potential time-of-day (TOD) interactions. Psychomotor function (processing speed), vigilance (visual attention), visual learning and memory, working memory (executive function), verbal learning and memory were examined. Capillary glucose, body temperature, urine specific gravity, and sleep volume were also recorded. Results Fasting effects were observed for psychomotor function (Cohen's d=1.3, P=0.01) and vigilance (d=0.6, P=0.004), with improved performance at 0900h during fasting; verbal learning and memory was poorer at 1600h (d=-0.8, P=0.03). A TOD effect was present for psychomotor function (d=-0.4, P<0.001), visual learning (d=-0.5, P=0.04), verbal learning and memory (d=-1.3, P=0.001), with poorer performances at 1600h. There was no significant fasting effect on visual learning and working memory. Conclusions Our results show that the effect of fasting on cognition is heterogeneous and domain-specific. Performance in functions requiring sustained rapid responses was better in the morning, declining in the late afternoon, whereas performance in non-speed dependent accuracy measures was more resilient. PMID:22375233

Fast Detection of Material Deformation through Structural Dissimilarity

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

Ushizima, Daniela; Perciano, Talita; Parkinson, Dilworth

2015-10-29

Designing materials that are resistant to extreme temperatures and brittleness relies on assessing structural dynamics of samples. Algorithms are critically important to characterize material deformation under stress conditions. Here, we report on our design of coarse-grain parallel algorithms for image quality assessment based on structural information and on crack detection of gigabyte-scale experimental datasets. We show how key steps can be decomposed into distinct processing flows, one based on structural similarity (SSIM) quality measure, and another on spectral content. These algorithms act upon image blocks that fit into memory, and can execute independently. We discuss the scientific relevance of themore » problem, key developments, and decomposition of complementary tasks into separate executions. We show how to apply SSIM to detect material degradation, and illustrate how this metric can be allied to spectral analysis for structure probing, while using tiled multi-resolution pyramids stored in HDF5 chunked multi-dimensional arrays. Results show that the proposed experimental data representation supports an average compression rate of 10X, and data compression scales linearly with the data size. We also illustrate how to correlate SSIM to crack formation, and how to use our numerical schemes to enable fast detection of deformation from 3D datasets evolving in time.« less

Further Examination of the Immediate Impact of Television on Children's Executive Function

ERIC Educational Resources Information Center

Lillard, Angeline S.; Drell, Marissa B.; Richey, Eve M.; Boguszewski, Katherine; Smith, Eric D.

2015-01-01

Three studies examined the short-term impact of television (TV) on children's executive function (EF). Study 1 (N = 160) showed that 4- and 6-year-olds' EF is impaired after watching 2 different fast and fantastical shows, relative to that of children who watched a slow, realistic show or played. In Study 2 (N = 60), 4-year-olds' EF was as…

Gaussian process tomography for soft x-ray spectroscopy at WEST without equilibrium information

NASA Astrophysics Data System (ADS)

Wang, T.; Mazon, D.; Svensson, J.; Li, D.; Jardin, A.; Verdoolaege, G.

2018-06-01

Gaussian process tomography (GPT) is a recently developed tomography method based on the Bayesian probability theory [J. Svensson, JET Internal Report EFDA-JET-PR(11)24, 2011 and Li et al., Rev. Sci. Instrum. 84, 083506 (2013)]. By modeling the soft X-ray (SXR) emissivity field in a poloidal cross section as a Gaussian process, the Bayesian SXR tomography can be carried out in a robust and extremely fast way. Owing to the short execution time of the algorithm, GPT is an important candidate for providing real-time reconstructions with a view to impurity transport and fast magnetohydrodynamic control. In addition, the Bayesian formalism allows quantifying uncertainty on the inferred parameters. In this paper, the GPT technique is validated using a synthetic data set expected from the WEST tokamak, and the results are shown of its application to the reconstruction of SXR emissivity profiles measured on Tore Supra. The method is compared with the standard algorithm based on minimization of the Fisher information.

Fast Dynamical Decoupling of the Mølmer-Sørensen Entangling Gate.

PubMed

Manovitz, Tom; Rotem, Amit; Shaniv, Ravid; Cohen, Itsik; Shapira, Yotam; Akerman, Nitzan; Retzker, Alex; Ozeri, Roee

2017-12-01

Engineering entanglement between quantum systems often involves coupling through a bosonic mediator, which should be disentangled from the systems at the operation's end. The quality of such an operation is generally limited by environmental and control noise. One of the prime techniques for suppressing noise is by dynamical decoupling, where one actively applies pulses at a rate that is faster than the typical time scale of the noise. However, for boson-mediated gates, current dynamical decoupling schemes require executing the pulses only when the boson and the quantum systems are disentangled. This restriction implies an increase of the gate time by a factor of sqrt[N], with N being the number of pulses applied. Here we propose and realize a method that enables dynamical decoupling in a boson-mediated system where the pulses can be applied while spin-boson entanglement persists, resulting in an increase in time that is at most a factor of π/2, independently of the number of pulses applied. We experimentally demonstrate the robustness of our entangling gate with fast dynamical decoupling to σ_{z} noise using ions in a Paul trap.

Faster Heavy Ion Transport for HZETRN

NASA Technical Reports Server (NTRS)

Slaba, Tony C.

2013-01-01

The deterministic particle transport code HZETRN was developed to enable fast and accurate space radiation transport through materials. As more complex transport solutions are implemented for neutrons, light ions (Z < 2), mesons, and leptons, it is important to maintain overall computational efficiency. In this work, the heavy ion (Z > 2) transport algorithm in HZETRN is reviewed, and a simple modification is shown to provide an approximate 5x decrease in execution time for galactic cosmic ray transport. Convergence tests and other comparisons are carried out to verify that numerical accuracy is maintained in the new algorithm.

Pulseq-Graphical Programming Interface: Open source visual environment for prototyping pulse sequences and integrated magnetic resonance imaging algorithm development.

PubMed

Ravi, Keerthi Sravan; Potdar, Sneha; Poojar, Pavan; Reddy, Ashok Kumar; Kroboth, Stefan; Nielsen, Jon-Fredrik; Zaitsev, Maxim; Venkatesan, Ramesh; Geethanath, Sairam

2018-03-11

To provide a single open-source platform for comprehensive MR algorithm development inclusive of simulations, pulse sequence design and deployment, reconstruction, and image analysis. We integrated the "Pulseq" platform for vendor-independent pulse programming with Graphical Programming Interface (GPI), a scientific development environment based on Python. Our integrated platform, Pulseq-GPI, permits sequences to be defined visually and exported to the Pulseq file format for execution on an MR scanner. For comparison, Pulseq files using either MATLAB only ("MATLAB-Pulseq") or Python only ("Python-Pulseq") were generated. We demonstrated three fundamental sequences on a 1.5 T scanner. Execution times of the three variants of implementation were compared on two operating systems. In vitro phantom images indicate equivalence with the vendor supplied implementations and MATLAB-Pulseq. The examples demonstrated in this work illustrate the unifying capability of Pulseq-GPI. The execution times of all the three implementations were fast (a few seconds). The software is capable of user-interface based development and/or command line programming. The tool demonstrated here, Pulseq-GPI, integrates the open-source simulation, reconstruction and analysis capabilities of GPI Lab with the pulse sequence design and deployment features of Pulseq. Current and future work includes providing an ISMRMRD interface and incorporating Specific Absorption Ratio and Peripheral Nerve Stimulation computations. Copyright © 2018 Elsevier Inc. All rights reserved.

Hybrid deterministic/stochastic simulation of complex biochemical systems.

PubMed

Lecca, Paola; Bagagiolo, Fabio; Scarpa, Marina

2017-11-21

In a biological cell, cellular functions and the genetic regulatory apparatus are implemented and controlled by complex networks of chemical reactions involving genes, proteins, and enzymes. Accurate computational models are indispensable means for understanding the mechanisms behind the evolution of a complex system, not always explored with wet lab experiments. To serve their purpose, computational models, however, should be able to describe and simulate the complexity of a biological system in many of its aspects. Moreover, it should be implemented by efficient algorithms requiring the shortest possible execution time, to avoid enlarging excessively the time elapsing between data analysis and any subsequent experiment. Besides the features of their topological structure, the complexity of biological networks also refers to their dynamics, that is often non-linear and stiff. The stiffness is due to the presence of molecular species whose abundance fluctuates by many orders of magnitude. A fully stochastic simulation of a stiff system is computationally time-expensive. On the other hand, continuous models are less costly, but they fail to capture the stochastic behaviour of small populations of molecular species. We introduce a new efficient hybrid stochastic-deterministic computational model and the software tool MoBioS (MOlecular Biology Simulator) implementing it. The mathematical model of MoBioS uses continuous differential equations to describe the deterministic reactions and a Gillespie-like algorithm to describe the stochastic ones. Unlike the majority of current hybrid methods, the MoBioS algorithm divides the reactions' set into fast reactions, moderate reactions, and slow reactions and implements a hysteresis switching between the stochastic model and the deterministic model. Fast reactions are approximated as continuous-deterministic processes and modelled by deterministic rate equations. Moderate reactions are those whose reaction waiting time is greater than the fast reaction waiting time but smaller than the slow reaction waiting time. A moderate reaction is approximated as a stochastic (deterministic) process if it was classified as a stochastic (deterministic) process at the time at which it crosses the threshold of low (high) waiting time. A Gillespie First Reaction Method is implemented to select and execute the slow reactions. The performances of MoBios were tested on a typical example of hybrid dynamics: that is the DNA transcription regulation. The simulated dynamic profile of the reagents' abundance and the estimate of the error introduced by the fully deterministic approach were used to evaluate the consistency of the computational model and that of the software tool.

An EMG study on characteristics of premotor and motor components in an agility reaction time test on athletes.

PubMed

Zhang, J; Chen, R; Wu, Y; Li, K; Wang, D; Liu, Y; Li, Y

2013-10-01

How do athletes control their foot movement so they can react fast in sports? Which component of the process may be more sensitive to training? These questions related to athletes' agility performance have long been important to the field of sport sciences, but are still unclear. The present study used surface electromyography (EMG) on the tibialis anterior (TA) and gastrocnemius medial (GM) of both left and right to assess if there would be any different contributions between premotor time (PRT) and motor time (MT) to the overall reaction time (RT). Fifty-five right-footed male college athletes (M=20.62 years old; SD=1.01) were required to respond to a random visual stimulus using foot movement as fast as possible in four different directions (i.e., forward and backward in their left or right foot). High correlation coefficients between PMT and RT in all four directions (ranging from 0.866 to 0.909) were revealed, but not between MT and RT (ranging from 0.131 to 0.336). Lateral and sagittal axes significantly interacted based on RT. The left forward direction was slowest among all directions. The process of decision making, not the preparation of execution, plays a significant role in fast and accurate reactive responses; the slowest RT in the forward direction of the left foot may be related to response programming. The corresponding training should be emphasized in order to improve athletes' agility performance.

Near-infrared imaging of the effects of glucose ingestion and regulation on prefrontal activation during dual-task execution in healthy fasting older adults.

PubMed

Gagnon, Christine; Desjardins-Crépeau, Laurence; Tournier, Isabelle; Desjardins, Michèle; Lesage, Frédéric; Greenwood, Carol E; Bherer, Louis

2012-06-15

Glucose enhancing effects in older adults have mostly been observed for episodic memory, but have recently been found for attentional control performance. Yet, brain activation patterns underlying these effects are still unknown. The present study examined the acute effects of glucose ingestion on prefrontal brain activation during the execution of a divided attention task in fasting non-diabetic older adults. Twenty older adults (60 years and older) took part in the study that included two experimental sessions. After an overnight fast, participants received either a glucose drink (50 g) or a placebo (saccharin) drink, following which they completed a dual-task. During task execution, prefrontal activation was recorded with functional near-infrared spectroscopy (fNIRS). A repeated-measures design was used such that each participant served as his or her own control. The two experimental sessions were counterbalanced among participants and were performed two weeks apart. When participants were in the glucose condition, they showed similar dual-task costs for both tasks, whereas in the placebo condition they prioritized one task over the other, with a significantly larger dual-task cost for the non-prioritized task (p<0.01). Differential brain activation was also observed in right ventral-lateral prefrontal regions for oxygenated hemoglobin and deoxygenated hemoglobin, with more activation apparent in the glucose condition (p<0.05). Furthermore, behavioral and activation data were influenced by individual differences in glucose regulation. Glucose ingestion appears to momentarily enhance fasting seniors' capacity to coordinate more equally two concurrent tasks and this is reflected in brain activation patterns. Copyright © 2012 Elsevier B.V. All rights reserved.

MAGI: many-component galaxy initializer

NASA Astrophysics Data System (ADS)

Miki, Yohei; Umemura, Masayuki

2018-04-01

Providing initial conditions is an essential procedure for numerical simulations of galaxies. The initial conditions for idealized individual galaxies in N-body simulations should resemble observed galaxies and be dynamically stable for time-scales much longer than their characteristic dynamical times. However, generating a galaxy model ab initio as a system in dynamical equilibrium is a difficult task, since a galaxy contains several components, including a bulge, disc, and halo. Moreover, it is desirable that the initial-condition generator be fast and easy to use. We have now developed an initial-condition generator for galactic N-body simulations that satisfies these requirements. The developed generator adopts a distribution-function-based method, and it supports various kinds of density models, including custom-tabulated inputs and the presence of more than one disc. We tested the dynamical stability of systems generated by our code, representing early- and late-type galaxies, with N = 2097 152 and 8388 608 particles, respectively, and we found that the model galaxies maintain their initial distributions for at least 1 Gyr. The execution times required to generate the two models were 8.5 and 221.7 seconds, respectively, which is negligible compared to typical execution times for N-body simulations. The code is provided as open-source software and is publicly and freely available at https://bitbucket.org/ymiki/magi.

Implementation and characterization of active feed-forward for deterministic linear optics quantum computing

NASA Astrophysics Data System (ADS)

Böhi, P.; Prevedel, R.; Jennewein, T.; Stefanov, A.; Tiefenbacher, F.; Zeilinger, A.

2007-12-01

In general, quantum computer architectures which are based on the dynamical evolution of quantum states, also require the processing of classical information, obtained by measurements of the actual qubits that make up the computer. This classical processing involves fast, active adaptation of subsequent measurements and real-time error correction (feed-forward), so that quantum gates and algorithms can be executed in a deterministic and hence error-free fashion. This is also true in the linear optical regime, where the quantum information is stored in the polarization state of photons. The adaptation of the photon’s polarization can be achieved in a very fast manner by employing electro-optical modulators, which change the polarization of a trespassing photon upon appliance of a high voltage. In this paper we discuss techniques for implementing fast, active feed-forward at the single photon level and we present their application in the context of photonic quantum computing. This includes the working principles and the characterization of the EOMs as well as a description of the switching logics, both of which allow quantum computation at an unprecedented speed.

Fast noninvasive eye-tracking and eye-gaze determination for biomedical and remote monitoring applications

NASA Astrophysics Data System (ADS)

Talukder, Ashit; Morookian, John M.; Monacos, Steve P.; Lam, Raymond K.; Lebaw, C.; Bond, A.

2004-04-01

Eyetracking is one of the latest technologies that has shown potential in several areas including human-computer interaction for people with and without disabilities, and for noninvasive monitoring, detection, and even diagnosis of physiological and neurological problems in individuals. Current non-invasive eyetracking methods achieve a 30 Hz rate with possibly low accuracy in gaze estimation, that is insufficient for many applications. We propose a new non-invasive visual eyetracking system that is capable of operating at speeds as high as 6-12 KHz. A new CCD video camera and hardware architecture is used, and a novel fast image processing algorithm leverages specific features of the input CCD camera to yield a real-time eyetracking system. A field programmable gate array (FPGA) is used to control the CCD camera and execute the image processing operations. Initial results show the excellent performance of our system under severe head motion and low contrast conditions.

The chief information officer--capturing healthcare's rare bird.

PubMed

Krinsky, M L

1986-08-01

While we occasionally conducted MIS executive searches during the 1970s, the recent pace has quickened substantially. Healthcare corporations need the MIS executive or CIO to keep the organization technologically and managerially current. Downsizing of acute-care facilities, expansion of outpatient services and creation of new programs have put a premium on current, computer-generated data. Skilled managers must rely on an efficient, flexible data processing department to evaluate options and make decisions about corporate strategy and program development. A presentable, articulate, personable MIS executive is a key ingredient in a successful management team. The position will continue to grow in importance and prominence in the fast-changing healthcare delivery industry.

F2Dock: Fast Fourier Protein-Protein Docking

PubMed Central

Bajaj, Chandrajit; Chowdhury, Rezaul; Siddavanahalli, Vinay

2009-01-01

The functions of proteins is often realized through their mutual interactions. Determining a relative transformation for a pair of proteins and their conformations which form a stable complex, reproducible in nature, is known as docking. It is an important step in drug design, structure determination and understanding function and structure relationships. In this paper we extend our non-uniform fast Fourier transform docking algorithm to include an adaptive search phase (both translational and rotational) and thereby speed up its execution. We have also implemented a multithreaded version of the adaptive docking algorithm for even faster execution on multicore machines. We call this protein-protein docking code F2Dock (F2 = Fast Fourier). We have calibrated F2Dock based on an extensive experimental study on a list of benchmark complexes and conclude that F2Dock works very well in practice. Though all docking results reported in this paper use shape complementarity and Coulombic potential based scores only, F2Dock is structured to incorporate Lennard-Jones potential and re-ranking docking solutions based on desolvation energy. PMID:21071796

Fast and predictable video compression in software design and implementation of an H.261 codec

NASA Astrophysics Data System (ADS)

Geske, Dagmar; Hess, Robert

1998-09-01

The use of software codecs for video compression becomes commonplace in several videoconferencing applications. In order to reduce conflicts with other applications used at the same time, mechanisms for resource reservation on endsystems need to determine an upper bound for computing time used by the codec. This leads to the demand for predictable execution times of compression/decompression. Since compression schemes as H.261 inherently depend on the motion contained in the video, an adaptive admission control is required. This paper presents a data driven approach based on dynamical reduction of the number of processed macroblocks in peak situations. Besides the absolute speed is a point of interest. The question, whether and how software compression of high quality video is feasible on today's desktop computers, is examined.

A fast sequence assembly method based on compressed data structures.

PubMed

Liang, Peifeng; Zhang, Yancong; Lin, Kui; Hu, Jinglu

2014-01-01

Assembling a large genome using next generation sequencing reads requires large computer memory and a long execution time. To reduce these requirements, a memory and time efficient assembler is presented from applying FM-index in JR-Assembler, called FMJ-Assembler, where FM stand for FMR-index derived from the FM-index and BWT and J for jumping extension. The FMJ-Assembler uses expanded FM-index and BWT to compress data of reads to save memory and jumping extension method make it faster in CPU time. An extensive comparison of the FMJ-Assembler with current assemblers shows that the FMJ-Assembler achieves a better or comparable overall assembly quality and requires lower memory use and less CPU time. All these advantages of the FMJ-Assembler indicate that the FMJ-Assembler will be an efficient assembly method in next generation sequencing technology.

“No-o-o-o Peeking”: Preschoolers’ Executive Control, Social Competence, and Classroom Adjustment

PubMed Central

Denham, Susanne A.; Bassett, Hideko H.; Sirotkin, Yana S.; Brown, Chavaughn; Morris, Carol S.

2015-01-01

The goals of this study were to evaluate (1) how specific aspects of executive control, briefly assessed, predict social competence and classroom adjustment during preschool; and (2) differences between two aspects of executive control, according to child’s age, socioeconomic risk status, and gender. The facets of executive control were defined as cool executive control (CEC; affectively neutral, slow acting, and late developing) and hot executive control (HEC; more emotional, fast acting, and early developing). Two hundred eighty-seven 3- to 5-year-old children from private child care and Head Start centers were directly assessed during executive control tasks, and preschool teachers provided information on their school success. Aspects of executive control varied with age, socioeconomic risk, and gender. Specifically, older children performed better on CEC tasks across three age levels; for HEC tasks, change was seen only between 3-year-olds and 4-year-olds. Children of mothers with less formal education performed less well on CEC than those whose mothers had more education; girls performed better than boys on HEC tasks. Further, facets of executive control were differentially related to later social competence and classroom adjustment. HEC predicted social competence, whereas CEC uniquely predicted classroom adjustment. Implications for everyday practice and specific curricula formulation are discussed. PMID:26166925

CQPSO scheduling algorithm for heterogeneous multi-core DAG task model

NASA Astrophysics Data System (ADS)

Zhai, Wenzheng; Hu, Yue-Li; Ran, Feng

2017-07-01

Efficient task scheduling is critical to achieve high performance in a heterogeneous multi-core computing environment. The paper focuses on the heterogeneous multi-core directed acyclic graph (DAG) task model and proposes a novel task scheduling method based on an improved chaotic quantum-behaved particle swarm optimization (CQPSO) algorithm. A task priority scheduling list was built. A processor with minimum cumulative earliest finish time (EFT) was acted as the object of the first task assignment. The task precedence relationships were satisfied and the total execution time of all tasks was minimized. The experimental results show that the proposed algorithm has the advantage of optimization abilities, simple and feasible, fast convergence, and can be applied to the task scheduling optimization for other heterogeneous and distributed environment.

Ultra-High Capacity Networking Enabled By Optical Technologies

DTIC Science & Technology

2003-08-01

interface that raises an interrupt regardless of what the kernel may be doing. Piglet also uses fast wakeup signals to optimise scheduling in certain...executed which switches context driectly to the now-runnable application i.e., without invoking the scheduler . Since the fast wakeup handler does not...and scheduling , the first one has been built and tested. 10 Gb/s data patterns have been generated with this board. A systems experiment has

OBJ-1, A Study in Executable Algebraic Formal Specification.

DTIC Science & Technology

1981-07-01

natural way; 2. Achievement of a high level of abstraction in a natural way; 3. The possibility of executing test cases; 4I. User definition of data types...languages. Goguen has defined a new data type, called symboltree, in OBJ. The purpose of this data type is to provide for fast checking of certain... data type work, is given in Appendix C of this report. K. Parsaye-Ghomi, with A. B. C. Sampaio of UCLA, has written a specification of a hardware

Context-dependent urgency influences speed-accuracy trade-offs in decision-making and movement execution.

PubMed

Thura, David; Cos, Ignasi; Trung, Jessica; Cisek, Paul

2014-12-03

Speed-accuracy tradeoffs (SATs) exist in both decision-making and movement control, and are generally studied separately. However, in natural behavior animals are free to adjust the time invested in deciding and moving so as to maximize their reward rate. Here, we investigate whether shared mechanisms exist for SAT adjustment in both decisions and actions. Two monkeys performed a reach decision task in which they watched 15 tokens jump, one every 200 ms, from a central circle to one of two peripheral targets, and had to guess which target would ultimately receive the majority of tokens. The monkeys could decide at any time, and once a target was reached, the remaining token movements accelerated to either 50 ms ("fast" block) or 150 ms ("slow" block). Decisions were generally earlier and less accurate in fast than slow blocks, and in both blocks, the criterion of accuracy decreased over time within each trial. This could be explained by a simple model in which sensory information is combined with a linearly growing urgency signal. Remarkably, the duration of the reaching movements produced after the decision decreased over time in a similar block-dependent manner as the criterion of accuracy estimated by the model. This suggests that SATs for deciding and acting are influenced by a shared urgency/vigor signal. Consistent with this, we observed that the vigor of saccades performed during the decision process was higher in fast than in slow blocks, suggesting the influence of a context-dependent global arousal. Copyright © 2014 the authors 0270-6474/14/3416442-13$15.00/0.

Lifetime Prediction of IGBT in a STATCOM Using Modified-Graphical Rainflow Counting Algorithm

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

Gopi Reddy, Lakshmi Reddy; Tolbert, Leon M; Ozpineci, Burak

Rainflow algorithms are one of the best counting methods used in fatigue and failure analysis [17]. There have been many approaches to the rainflow algorithm, some proposing modifications. Graphical Rainflow Method (GRM) was proposed recently with a claim of faster execution times [10]. However, the steps of the graphical method of rainflow algorithm, when implemented, do not generate the same output as the four-point or ASTM standard algorithm. A modified graphical method is presented and discussed in this paper to overcome the shortcomings of graphical rainflow algorithm. A fast rainflow algorithm based on four-point algorithm but considering point comparison thanmore » range comparison is also presented. A comparison between the performances of the common rainflow algorithms [6-10], including the proposed methods, in terms of execution time, memory used, and efficiency, complexity, and load sequences is presented. Finally, the rainflow algorithm is applied to temperature data of an IGBT in assessing the lifetime of a STATCOM operating for power factor correction of the load. From 5-minute data load profiles available, the lifetime is estimated to be at 3.4 years.« less

Alternate Tritium Production Methods Using A Liquid Lithium Target

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

Wilson, J.

For over 60 years, the Savannah River Site’s primary mission has been the production of tritium. From the beginning, the Savannah River National Laboratory (SRNL) has provided the technical foundation to ensure the successful execution of this critical defense mission. SRNL has developed most of the processes used in the tritium mission and provides the research and development necessary to supply this critical component. This project was executed by first developing reactor models that could be used as a neutron source. In parallel to this development calculations were carried out testing the feasibility of accelerator technologies that could also bemore » used for tritium production. Targets were designed with internal moderating material and optimized target was calculated to be capable of 3000 grams using a 1400 MWt sodium fast reactor, 850 grams using a 400 MWt sodium fast reactor, and 100 grams using a 62 MWt reactor, annually.« less

The fast and the slow of skilled bimanual rhythm production: parallel versus integrated timing.

PubMed

Krampe, R T; Kliegl, R; Mayr, U; Engbert, R; Vorberg, D

2000-02-01

Professional pianists performed 2 bimanual rhythms at a wide range of different tempos. The polyrhythmic task required the combination of 2 isochronous sequences (3 against 4) between the hands; in the syncopated rhythm task successive keystrokes formed intervals of identical (isochronous) durations. At slower tempos, pianists relied on integrated timing control merging successive intervals between the hands into a common reference frame. A timer-motor model is proposed based on the concepts of rate fluctuation and the distinction between target specification and timekeeper execution processes as a quantitative account of performance at slow tempos. At rapid rates expert pianists used hand-independent, parallel timing control. In alternative to a model based on a single central clock, findings support a model of flexible control structures with multiple timekeepers that can work in parallel to accommodate specific task constraints.

Fast GPU-based Monte Carlo simulations for LDR prostate brachytherapy.

PubMed

Bonenfant, Éric; Magnoux, Vincent; Hissoiny, Sami; Ozell, Benoît; Beaulieu, Luc; Després, Philippe

2015-07-07

The aim of this study was to evaluate the potential of bGPUMCD, a Monte Carlo algorithm executed on Graphics Processing Units (GPUs), for fast dose calculations in permanent prostate implant dosimetry. It also aimed to validate a low dose rate brachytherapy source in terms of TG-43 metrics and to use this source to compute dose distributions for permanent prostate implant in very short times. The physics of bGPUMCD was reviewed and extended to include Rayleigh scattering and fluorescence from photoelectric interactions for all materials involved. The radial and anisotropy functions were obtained for the Nucletron SelectSeed in TG-43 conditions. These functions were compared to those found in the MD Anderson Imaging and Radiation Oncology Core brachytherapy source registry which are considered the TG-43 reference values. After appropriate calibration of the source, permanent prostate implant dose distributions were calculated for four patients and compared to an already validated Geant4 algorithm. The radial function calculated from bGPUMCD showed excellent agreement (differences within 1.3%) with TG-43 accepted values. The anisotropy functions at r = 1 cm and r = 4 cm were within 2% of TG-43 values for angles over 17.5°. For permanent prostate implants, Monte Carlo-based dose distributions with a statistical uncertainty of 1% or less for the target volume were obtained in 30 s or less for 1 × 1 × 1 mm(3) calculation grids. Dosimetric indices were very similar (within 2.7%) to those obtained with a validated, independent Monte Carlo code (Geant4) performing the calculations for the same cases in a much longer time (tens of minutes to more than a hour). bGPUMCD is a promising code that lets envision the use of Monte Carlo techniques in a clinical environment, with sub-minute execution times on a standard workstation. Future work will explore the use of this code with an inverse planning method to provide a complete Monte Carlo-based planning solution.

Fast GPU-based Monte Carlo simulations for LDR prostate brachytherapy

NASA Astrophysics Data System (ADS)

Bonenfant, Éric; Magnoux, Vincent; Hissoiny, Sami; Ozell, Benoît; Beaulieu, Luc; Després, Philippe

2015-07-01

The aim of this study was to evaluate the potential of bGPUMCD, a Monte Carlo algorithm executed on Graphics Processing Units (GPUs), for fast dose calculations in permanent prostate implant dosimetry. It also aimed to validate a low dose rate brachytherapy source in terms of TG-43 metrics and to use this source to compute dose distributions for permanent prostate implant in very short times. The physics of bGPUMCD was reviewed and extended to include Rayleigh scattering and fluorescence from photoelectric interactions for all materials involved. The radial and anisotropy functions were obtained for the Nucletron SelectSeed in TG-43 conditions. These functions were compared to those found in the MD Anderson Imaging and Radiation Oncology Core brachytherapy source registry which are considered the TG-43 reference values. After appropriate calibration of the source, permanent prostate implant dose distributions were calculated for four patients and compared to an already validated Geant4 algorithm. The radial function calculated from bGPUMCD showed excellent agreement (differences within 1.3%) with TG-43 accepted values. The anisotropy functions at r = 1 cm and r = 4 cm were within 2% of TG-43 values for angles over 17.5°. For permanent prostate implants, Monte Carlo-based dose distributions with a statistical uncertainty of 1% or less for the target volume were obtained in 30 s or less for 1 × 1 × 1 mm3 calculation grids. Dosimetric indices were very similar (within 2.7%) to those obtained with a validated, independent Monte Carlo code (Geant4) performing the calculations for the same cases in a much longer time (tens of minutes to more than a hour). bGPUMCD is a promising code that lets envision the use of Monte Carlo techniques in a clinical environment, with sub-minute execution times on a standard workstation. Future work will explore the use of this code with an inverse planning method to provide a complete Monte Carlo-based planning solution.

Fast Depiction Invariant Visual Similarity for Content Based Image Retrieval Based on Data-driven Visual Similarity using Linear Discriminant Analysis

NASA Astrophysics Data System (ADS)

Wihardi, Y.; Setiawan, W.; Nugraha, E.

2018-01-01

On this research we try to build CBIRS based on Learning Distance/Similarity Function using Linear Discriminant Analysis (LDA) and Histogram of Oriented Gradient (HoG) feature. Our method is invariant to depiction of image, such as similarity of image to image, sketch to image, and painting to image. LDA can decrease execution time compared to state of the art method, but it still needs an improvement in term of accuracy. Inaccuracy in our experiment happen because we did not perform sliding windows search and because of low number of negative samples as natural-world images.

Employing OpenCL to Accelerate Ab Initio Calculations on Graphics Processing Units.

PubMed

Kussmann, Jörg; Ochsenfeld, Christian

2017-06-13

We present an extension of our graphics processing units (GPU)-accelerated quantum chemistry package to employ OpenCL compute kernels, which can be executed on a wide range of computing devices like CPUs, Intel Xeon Phi, and AMD GPUs. Here, we focus on the use of AMD GPUs and discuss differences as compared to CUDA-based calculations on NVIDIA GPUs. First illustrative timings are presented for hybrid density functional theory calculations using serial as well as parallel compute environments. The results show that AMD GPUs are as fast or faster than comparable NVIDIA GPUs and provide a viable alternative for quantum chemical applications.

Impact force and time analysis influenced by execution distance in a roundhouse kick to the head in taekwondo.

PubMed

Estevan, Isaac; Alvarez, Octavio; Falco, Coral; Molina-García, Javier; Castillo, Isabel

2011-10-01

The execution distance is a tactic factor that affects mechanical performance and execution technique in taekwondo. This study analyzes the roundhouse kick to the head by comparing the maximum impact force, execution time, and impact time in 3 distances according to the athletes' competition level. It also analyzes the relationship between impact force and weight in each group. It examines whether the execution distance affects the maximum impact force, execution time, and impact time, in each level group or 2 different competition levels. Participants were 27 male taekwondo players (13 medallists and 14 nonmedallists). The medallists executed the roundhouse kick to the head with greater impact force and in a shorter execution time than did the nonmedallists when they kicked from any distance different to their combat distance. However, the results showed that the execution distance is influential in the execution time and impact time in the nonmedallist group. It is considered appropriate to orientate the high-level competitors to train for offensive actions from any distance similar to the long execution distance because it offers equally effectiveness and a greater security against the opponent. Also, practitioners should focus their training to improve time performance because it is more affected by distance than impact force.

Potential of adult mammalian lumbosacral spinal cord to execute and acquire improved locomotion in the absence of supraspinal input

NASA Technical Reports Server (NTRS)

Edgerton, V. R.; Roy, R. R.; Hodgson, J. A.; Prober, R. J.; de Guzman, C. P.; de Leon, R.

1992-01-01

The neural circuitry of the lumbar spinal cord can generate alternating extension and flexion of the hindlimbs. The hindlimbs of adult cats with complete transection of the spinal cord at a low thoracic level (T12-T13) can perform full weight-supporting locomotion on a treadmill belt moving at a range of speeds. Some limitations in the locomotor capacity can be associated with a deficit in the recruitment level of the fast extensors during the stance phase and the flexors during the swing phase of a step cycle. The level of locomotor performance, however, can be enhanced by daily training on a treadmill while emphasizing full weight-support stepping and by providing appropriately timed sensory stimulation, loading, and/or pharmacologic stimulation of the hindlimb neuromuscular apparatus. Furthermore, there appears to be an interactive effect of these interventions. For example, the maximum treadmill speed that a spinal adult cat can attain and maintain is significantly improved with daily full weight-supporting treadmill training, but progressive recruitment of fast extensors becomes apparent only when the hindlimbs are loaded by gently pulling down on the tail during the stepping. Stimulation of the sural nerve at the initiation of the flexion phase of the step cycle can likewise markedly improve the locomotor capability. Administration of clonidine, in particular in combination with an elevated load, resulted in the most distinct and consistent alternating bursts of electromyographic activity during spinal stepping. These data indicate that the spinal cord has the ability to execute alternating activation of the extensor and flexor musculature of the hindlimbs (stepping) and that this ability can be improved by several interventions such as training, sensory stimulation, and use of some pharmacologic agents. Thus, it appears that the spinal cord, without supraspinal input, is highly plastic and has the potential to "learn," that is, to acquire and improve its ability to execute full weight-supporting locomotion on a treadmill belt.

IpexT: Integrated Planning and Execution for Military Satellite Tele-Communications

NASA Technical Reports Server (NTRS)

Plaunt, Christian; Rajan, Kanna

2004-01-01

The next generation of military communications satellites may be designed as a fast packet-switched constellation of spacecraft able to withstand substantial bandwidth capacity fluctuation in the face of dynamic resource utilization and rapid environmental changes including jamming of communication frequencies and unstable weather phenomena. We are in the process of designing an integrated scheduling and execution tool which will aid in the analysis of the design parameters needed for building such a distributed system for nominal and battlefield communications. This paper discusses the design of such a system based on a temporal constraint posting planner/scheduler and a smart executive which can cope with a dynamic environment to make a more optimal utilization of bandwidth than the current circuit switched based approach.

Speed and accuracy improvements in FLAASH atmospheric correction of hyperspectral imagery

NASA Astrophysics Data System (ADS)

Perkins, Timothy; Adler-Golden, Steven; Matthew, Michael W.; Berk, Alexander; Bernstein, Lawrence S.; Lee, Jamine; Fox, Marsha

2012-11-01

Remotely sensed spectral imagery of the earth's surface can be used to fullest advantage when the influence of the atmosphere has been removed and the measurements are reduced to units of reflectance. Here, we provide a comprehensive summary of the latest version of the Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes atmospheric correction algorithm. We also report some new code improvements for speed and accuracy. These include the re-working of the original algorithm in C-language code parallelized with message passing interface and containing a new radiative transfer look-up table option, which replaces executions of the MODTRAN model. With computation times now as low as ~10 s per image per computer processor, automated, real-time, on-board atmospheric correction of hyper- and multi-spectral imagery is within reach.

A new Lagrangian random choice method for steady two-dimensional supersonic/hypersonic flow

NASA Technical Reports Server (NTRS)

Loh, C. Y.; Hui, W. H.

1991-01-01

Glimm's (1965) random choice method has been successfully applied to compute steady two-dimensional supersonic/hypersonic flow using a new Lagrangian formulation. The method is easy to program, fast to execute, yet it is very accurate and robust. It requires no grid generation, resolves slipline and shock discontinuities crisply, can handle boundary conditions most easily, and is applicable to hypersonic as well as supersonic flow. It represents an accurate and fast alternative to the existing Eulerian methods. Many computed examples are given.

Performance enhancement of various real-time image processing techniques via speculative execution

NASA Astrophysics Data System (ADS)

Younis, Mohamed F.; Sinha, Purnendu; Marlowe, Thomas J.; Stoyenko, Alexander D.

1996-03-01

In real-time image processing, an application must satisfy a set of timing constraints while ensuring the semantic correctness of the system. Because of the natural structure of digital data, pure data and task parallelism have been used extensively in real-time image processing to accelerate the handling time of image data. These types of parallelism are based on splitting the execution load performed by a single processor across multiple nodes. However, execution of all parallel threads is mandatory for correctness of the algorithm. On the other hand, speculative execution is an optimistic execution of part(s) of the program based on assumptions on program control flow or variable values. Rollback may be required if the assumptions turn out to be invalid. Speculative execution can enhance average, and sometimes worst-case, execution time. In this paper, we target various image processing techniques to investigate applicability of speculative execution. We identify opportunities for safe and profitable speculative execution in image compression, edge detection, morphological filters, and blob recognition.

The transience and nature of cognitive impairments in transient global amnesia: a meta-analysis.

PubMed

Jäger, Theodor; Bäzner, Hansjörg; Kliegel, Matthias; Szabo, Kristina; Hennerici, Michael G

2009-01-01

Transient global amnesia (TGA) is a clinical syndrome characterized by the sudden onset of severe amnesia without concomitant focal neurological symptoms. This meta-analysis of the cognitive characteristics of TGA addressed two main issues. First, we examined the hypothesis that the acute phase of TGA is associated with changes of anterograde and retrograde episodic long-term memory sparing semantic and short-term memory, while we had no clear prediction for potential reductions of executive functions due to the relative lack of previous studies addressing this issue. Second, we analyzed the time-course of changes in cognitive functions throughout three time intervals--acute (0-24 hours after TGA onset), postacute (24 hours to 5 days), and long-term phase (5-30 days)--to reveal whether there is a fast versus a delayed recovery. The results of the meta-analysis on 152 effect sizes from 25 studies showed that TGA is characterized by an extraordinarily large reduction of anterograde (d* = 1.89) and a somewhat milder reduction of retrograde (d* = 1.28) episodic long-term memory. Moreover, our results indicate the existence of additional, nonamnestic cognitive changes during TGA, because executive functions were also diminished (d* = 0.79). Reductions in both anterograde episodic long-term memory and executive function recover slowly, as slightly poorer performance in these cognitive domains can be found in the postacute phase (d*s = 0.32 and 0.44). All cognitive diminutions resolved within the long-term phase, by this calling into question previous reports of poorer performance of TGA patients relative to comparison subjects weeks or months after the attack.

Efficient Helicopter Aerodynamic and Aeroacoustic Predictions on Parallel Computers

NASA Technical Reports Server (NTRS)

Wissink, Andrew M.; Lyrintzis, Anastasios S.; Strawn, Roger C.; Oliker, Leonid; Biswas, Rupak

1996-01-01

This paper presents parallel implementations of two codes used in a combined CFD/Kirchhoff methodology to predict the aerodynamics and aeroacoustics properties of helicopters. The rotorcraft Navier-Stokes code, TURNS, computes the aerodynamic flowfield near the helicopter blades and the Kirchhoff acoustics code computes the noise in the far field, using the TURNS solution as input. The overall parallel strategy adds MPI message passing calls to the existing serial codes to allow for communication between processors. As a result, the total code modifications required for parallel execution are relatively small. The biggest bottleneck in running the TURNS code in parallel comes from the LU-SGS algorithm that solves the implicit system of equations. We use a new hybrid domain decomposition implementation of LU-SGS to obtain good parallel performance on the SP-2. TURNS demonstrates excellent parallel speedups for quasi-steady and unsteady three-dimensional calculations of a helicopter blade in forward flight. The execution rate attained by the code on 114 processors is six times faster than the same cases run on one processor of the Cray C-90. The parallel Kirchhoff code also shows excellent parallel speedups and fast execution rates. As a performance demonstration, unsteady acoustic pressures are computed at 1886 far-field observer locations for a sample acoustics problem. The calculation requires over two hundred hours of CPU time on one C-90 processor but takes only a few hours on 80 processors of the SP2. The resultant far-field acoustic field is analyzed with state of-the-art audio and video rendering of the propagating acoustic signals.

A fast algorithm for forward-modeling of gravitational fields in spherical coordinates with 3D Gauss-Legendre quadrature

NASA Astrophysics Data System (ADS)

Zhao, G.; Liu, J.; Chen, B.; Guo, R.; Chen, L.

2017-12-01

Forward modeling of gravitational fields at large-scale requires to consider the curvature of the Earth and to evaluate the Newton's volume integral in spherical coordinates. To acquire fast and accurate gravitational effects for subsurface structures, subsurface mass distribution is usually discretized into small spherical prisms (called tesseroids). The gravity fields of tesseroids are generally calculated numerically. One of the commonly used numerical methods is the 3D Gauss-Legendre quadrature (GLQ). However, the traditional GLQ integration suffers from low computational efficiency and relatively poor accuracy when the observation surface is close to the source region. We developed a fast and high accuracy 3D GLQ integration based on the equivalence of kernel matrix, adaptive discretization and parallelization using OpenMP. The equivalence of kernel matrix strategy increases efficiency and reduces memory consumption by calculating and storing the same matrix elements in each kernel matrix just one time. In this method, the adaptive discretization strategy is used to improve the accuracy. The numerical investigations show that the executing time of the proposed method is reduced by two orders of magnitude compared with the traditional method that without these optimized strategies. High accuracy results can also be guaranteed no matter how close the computation points to the source region. In addition, the algorithm dramatically reduces the memory requirement by N times compared with the traditional method, where N is the number of discretization of the source region in the longitudinal direction. It makes the large-scale gravity forward modeling and inversion with a fine discretization possible.

A window-based time series feature extraction method.

PubMed

Katircioglu-Öztürk, Deniz; Güvenir, H Altay; Ravens, Ursula; Baykal, Nazife

2017-10-01

This study proposes a robust similarity score-based time series feature extraction method that is termed as Window-based Time series Feature ExtraCtion (WTC). Specifically, WTC generates domain-interpretable results and involves significantly low computational complexity thereby rendering itself useful for densely sampled and populated time series datasets. In this study, WTC is applied to a proprietary action potential (AP) time series dataset on human cardiomyocytes and three precordial leads from a publicly available electrocardiogram (ECG) dataset. This is followed by comparing WTC in terms of predictive accuracy and computational complexity with shapelet transform and fast shapelet transform (which constitutes an accelerated variant of the shapelet transform). The results indicate that WTC achieves a slightly higher classification performance with significantly lower execution time when compared to its shapelet-based alternatives. With respect to its interpretable features, WTC has a potential to enable medical experts to explore definitive common trends in novel datasets. Copyright © 2017 Elsevier Ltd. All rights reserved.

Contributions from associative and explicit sequence knowledge to the execution of discrete keying sequences.

PubMed

Verwey, Willem B

2015-05-01

Research has provided many indications that highly practiced 6-key sequences are carried out in a chunking mode in which key-specific stimuli past the first are largely ignored. When in such sequences a deviating stimulus occasionally occurs at an unpredictable location, participants fall back to responding to individual stimuli (Verwey & Abrahamse, 2012). The observation that in such a situation execution still benefits from prior practice has been attributed to the possibility to operate in an associative mode. To better understand the contribution to the execution of keying sequences of motor chunks, associative sequence knowledge and also of explicit sequence knowledge, the present study tested three alternative accounts for the earlier finding of an execution rate increase at the end of 6-key sequences performed in the associative mode. The results provide evidence that the earlier observed execution rate increase can be attributed to the use of explicit sequence knowledge. In the present experiment this benefit was limited to sequences that are executed at the moderately fast rates of the associative mode, and occurred at both the earlier and final elements of the sequences. Copyright © 2015 Elsevier B.V. All rights reserved.

Message passing with queues and channels

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

Dozsa, Gabor J; Heidelberger, Philip; Kumar, Sameer

In an embodiment, a reception thread receives a source node identifier, a type, and a data pointer from an application and, in response, creates a receive request. If the source node identifier specifies a source node, the reception thread adds the receive request to a fast-post queue. If a message received from a network does not match a receive request on a posted queue, a polling thread adds a receive request that represents the message to an unexpected queue. If the fast-post queue contains the receive request, the polling thread removes the receive request from the fast-post queue. If themore » receive request that was removed from the fast-post queue does not match the receive request on the unexpected queue, the polling thread adds the receive request that was removed from the fast-post queue to the posted queue. The reception thread and the polling thread execute asynchronously from each other.« less

Development of the Fully Adaptive Storm Tide (FAST) Model for hurricane induced storm surges and associated inundation

NASA Astrophysics Data System (ADS)

Teng, Y. C.; Kelly, D.; Li, Y.; Zhang, K.

2016-02-01

A new state-of-the-art model (the Fully Adaptive Storm Tide model, FAST) for the prediction of storm surges over complex landscapes is presented. The FAST model is based on the conservation form of the full non-linear depth-averaged long wave equations. The equations are solved via an explicit finite volume scheme with interfacial fluxes being computed via Osher's approximate Riemann solver. Geometric source terms are treated in a high order manner that is well-balanced. The numerical solution technique has been chosen to enable the accurate simulation of wetting and drying over complex topography. Another important feature of the FAST model is the use of a simple underlying Cartesian mesh with tree-based static and dynamic adaptive mesh refinement (AMR). This permits the simulation of unsteady flows over varying landscapes (including localized features such as canals) by locally increasing (or relaxing) grid resolution in a dynamic fashion. The use of (dynamic) AMR lowers the computational cost of the storm surge model whilst retaining high resolution (and thus accuracy) where and when it is required. In additional, the FAST model has been designed to execute in a parallel computational environment with localized time-stepping. The FAST model has already been carefully verified against a series of benchmark type problems (Kelly et al. 2015). Here we present two simulations of the storm tide due to Hurricane Ike(2008) and Hurricane Sandy (2012). The model incorporates high resolution LIDAR data for the major portion of the New York City. Results compare favorably with water elevations measured by NOAA tidal gauges, by mobile sensors deployed and high water marks collected by the USGS.

Subthalamic nucleus gamma activity increases not only during movement but also during movement inhibition

PubMed Central

Fischer, Petra; Pogosyan, Alek; Herz, Damian M; Cheeran, Binith; Green, Alexander L; Fitzgerald, James; Aziz, Tipu Z; Hyam, Jonathan; Little, Simon; Foltynie, Thomas; Limousin, Patricia; Zrinzo, Ludvic; Brown, Peter; Tan, Huiling

2017-01-01

Gamma activity in the subthalamic nucleus (STN) is widely viewed as a pro-kinetic rhythm. Here we test the hypothesis that rather than being specifically linked to movement execution, gamma activity reflects dynamic processing in this nucleus. We investigated the role of gamma during fast stopping and recorded scalp electroencephalogram and local field potentials from deep brain stimulation electrodes in 9 Parkinson’s disease patients. Patients interrupted finger tapping (paced by a metronome) in response to a stop-signal sound, which was timed such that successful stopping would occur only in ~50% of all trials. STN gamma (60–90 Hz) increased most strongly when the tap was successfully stopped, whereas phase-based connectivity between the contralateral STN and motor cortex decreased. Beta or theta power seemed less directly related to stopping. In summary, STN gamma activity may support flexible motor control as it did not only increase during movement execution but also during rapid action-stopping. DOI: http://dx.doi.org/10.7554/eLife.23947.001 PMID:28742498

Utility functions and resource management in an oversubscribed heterogeneous computing environment

DOE PAGES

Khemka, Bhavesh; Friese, Ryan; Briceno, Luis Diego; ...

2014-09-26

We model an oversubscribed heterogeneous computing system where tasks arrive dynamically and a scheduler maps the tasks to machines for execution. The environment and workloads are based on those being investigated by the Extreme Scale Systems Center at Oak Ridge National Laboratory. Utility functions that are designed based on specifications from the system owner and users are used to create a metric for the performance of resource allocation heuristics. Each task has a time-varying utility (importance) that the enterprise will earn based on when the task successfully completes execution. We design multiple heuristics, which include a technique to drop lowmore » utility-earning tasks, to maximize the total utility that can be earned by completing tasks. The heuristics are evaluated using simulation experiments with two levels of oversubscription. The results show the benefit of having fast heuristics that account for the importance of a task and the heterogeneity of the environment when making allocation decisions in an oversubscribed environment. Furthermore, the ability to drop low utility-earning tasks allow the heuristics to tolerate the high oversubscription as well as earn significant utility.« less

A Sampling Based Approach to Spacecraft Autonomous Maneuvering with Safety Specifications

NASA Technical Reports Server (NTRS)

Starek, Joseph A.; Barbee, Brent W.; Pavone, Marco

2015-01-01

This paper presents a methods for safe spacecraft autonomous maneuvering that leverages robotic motion-planning techniques to spacecraft control. Specifically the scenario we consider is an in-plan rendezvous of a chaser spacecraft in proximity to a target spacecraft at the origin of the Clohessy Wiltshire Hill frame. The trajectory for the chaser spacecraft is generated in a receding horizon fashion by executing a sampling based robotic motion planning algorithm name Fast Marching Trees (FMT) which efficiently grows a tree of trajectories over a set of probabillistically drawn samples in the state space. To enforce safety the tree is only grown over actively safe samples for which there exists a one-burn collision avoidance maneuver that circularizes the spacecraft orbit along a collision-free coasting arc and that can be executed under potential thrusters failures. The overall approach establishes a provably correct framework for the systematic encoding of safety specifications into the spacecraft trajectory generations process and appears amenable to real time implementation on orbit. Simulation results are presented for a two-fault tolerant spacecraft during autonomous approach to a single client in Low Earth Orbit.

Detecting wrong notes in advance: neuronal correlates of error monitoring in pianists.

PubMed

Ruiz, María Herrojo; Jabusch, Hans-Christian; Altenmüller, Eckart

2009-11-01

Music performance is an extremely rapid process with low incidence of errors even at the fast rates of production required. This is possible only due to the fast functioning of the self-monitoring system. Surprisingly, no specific data about error monitoring have been published in the music domain. Consequently, the present study investigated the electrophysiological correlates of executive control mechanisms, in particular error detection, during piano performance. Our target was to extend the previous research efforts on understanding of the human action-monitoring system by selecting a highly skilled multimodal task. Pianists had to retrieve memorized music pieces at a fast tempo in the presence or absence of auditory feedback. Our main interest was to study the interplay between auditory and sensorimotor information in the processes triggered by an erroneous action, considering only wrong pitches as errors. We found that around 70 ms prior to errors a negative component is elicited in the event-related potentials and is generated by the anterior cingulate cortex. Interestingly, this component was independent of the auditory feedback. However, the auditory information did modulate the processing of the errors after their execution, as reflected in a larger error positivity (Pe). Our data are interpreted within the context of feedforward models and the auditory-motor coupling.

RCQ-GA: RDF Chain Query Optimization Using Genetic Algorithms

NASA Astrophysics Data System (ADS)

Hogenboom, Alexander; Milea, Viorel; Frasincar, Flavius; Kaymak, Uzay

The application of Semantic Web technologies in an Electronic Commerce environment implies a need for good support tools. Fast query engines are needed for efficient querying of large amounts of data, usually represented using RDF. We focus on optimizing a special class of SPARQL queries, the so-called RDF chain queries. For this purpose, we devise a genetic algorithm called RCQ-GA that determines the order in which joins need to be performed for an efficient evaluation of RDF chain queries. The approach is benchmarked against a two-phase optimization algorithm, previously proposed in literature. The more complex a query is, the more RCQ-GA outperforms the benchmark in solution quality, execution time needed, and consistency of solution quality. When the algorithms are constrained by a time limit, the overall performance of RCQ-GA compared to the benchmark further improves.

Disentangling Complexity in Bayesian Automatic Adaptive Quadrature

NASA Astrophysics Data System (ADS)

Adam, Gheorghe; Adam, Sanda

2018-02-01

The paper describes a Bayesian automatic adaptive quadrature (BAAQ) solution for numerical integration which is simultaneously robust, reliable, and efficient. Detailed discussion is provided of three main factors which contribute to the enhancement of these features: (1) refinement of the m-panel automatic adaptive scheme through the use of integration-domain-length-scale-adapted quadrature sums; (2) fast early problem complexity assessment - enables the non-transitive choice among three execution paths: (i) immediate termination (exceptional cases); (ii) pessimistic - involves time and resource consuming Bayesian inference resulting in radical reformulation of the problem to be solved; (iii) optimistic - asks exclusively for subrange subdivision by bisection; (3) use of the weaker accuracy target from the two possible ones (the input accuracy specifications and the intrinsic integrand properties respectively) - results in maximum possible solution accuracy under minimum possible computing time.

Aridopsis COBRA-LIKE 10, a GPI-anchored protien, mediates directional growth of pollen tubes

USDA-ARS?s Scientific Manuscript database

Successful reproduction of flowering plants requires constant communication between female tissues and growing pollen tubes. Female cells secrete molecules and peptides as nutrients or guidance cues for fast and directional tube growth, which is executed by dynamic changes of intracellular activitie...

Limbic and Basal Ganglia Neuroanatomical Correlates of Gait and Executive Function: Older Adults With Mild Cognitive Impairment and Intact Cognition.

PubMed

McGough, Ellen L; Kelly, Valerie E; Weaver, Kurt E; Logsdon, Rebecca G; McCurry, Susan M; Pike, Kenneth C; Grabowski, Thomas J; Teri, Linda

2018-04-01

This study aimed to examine differences in spatiotemporal gait parameters between older adults with amnestic mild cognitive impairment and normal cognition and to examine limbic and basal ganglia neural correlates of gait and executive function in older adults without dementia. This was a cross-sectional study of 46 community-dwelling older adults, ages 70-95 yrs, with amnestic mild cognitive impairment (n = 23) and normal cognition (n = 23). Structural magnetic resonance imaging was used to attain volumetric measures of limbic and basal ganglia structures. Quantitative motion analysis was used to measure spatiotemporal parameters of gait. The Trail Making Test was used to assess executive function. During fast-paced walking, older adults with amnestic mild cognitive impairment demonstrated significantly slower gait speed and shorter stride length compared with older adults with normal cognition. Stride length was positively correlated with hippocampal, anterior cingulate, and nucleus accumbens volumes (P < 0.05). Executive function was positively correlated with hippocampal, anterior cingulate, and posterior cingulate volumes (P < 0.05). Compared with older adults with normal cognition, those with amnestic mild cognitive impairment demonstrated slower gait speed and shorter stride length, during fast-paced walking, and lower executive function. Hippocampal and anterior cingulate volumes demonstrated moderate positive correlation with both gait and executive function, after adjusting for age. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) discuss gait performance and cognitive function in older adults with amnestic mild cognitive impairment versus normal cognition, (2) discuss neurocorrelates of gait and executive function in older adults without dementia, and (3) recognize the importance of assessing gait speed and cognitive function in the clinical management of older adults at risk for dementia. Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 0.5 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Closha: bioinformatics workflow system for the analysis of massive sequencing data.

PubMed

Ko, GunHwan; Kim, Pan-Gyu; Yoon, Jongcheol; Han, Gukhee; Park, Seong-Jin; Song, Wangho; Lee, Byungwook

2018-02-19

While next-generation sequencing (NGS) costs have fallen in recent years, the cost and complexity of computation remain substantial obstacles to the use of NGS in bio-medical care and genomic research. The rapidly increasing amounts of data available from the new high-throughput methods have made data processing infeasible without automated pipelines. The integration of data and analytic resources into workflow systems provides a solution to the problem by simplifying the task of data analysis. To address this challenge, we developed a cloud-based workflow management system, Closha, to provide fast and cost-effective analysis of massive genomic data. We implemented complex workflows making optimal use of high-performance computing clusters. Closha allows users to create multi-step analyses using drag and drop functionality and to modify the parameters of pipeline tools. Users can also import the Galaxy pipelines into Closha. Closha is a hybrid system that enables users to use both analysis programs providing traditional tools and MapReduce-based big data analysis programs simultaneously in a single pipeline. Thus, the execution of analytics algorithms can be parallelized, speeding up the whole process. We also developed a high-speed data transmission solution, KoDS, to transmit a large amount of data at a fast rate. KoDS has a file transfer speed of up to 10 times that of normal FTP and HTTP. The computer hardware for Closha is 660 CPU cores and 800 TB of disk storage, enabling 500 jobs to run at the same time. Closha is a scalable, cost-effective, and publicly available web service for large-scale genomic data analysis. Closha supports the reliable and highly scalable execution of sequencing analysis workflows in a fully automated manner. Closha provides a user-friendly interface to all genomic scientists to try to derive accurate results from NGS platform data. The Closha cloud server is freely available for use from http://closha.kobic.re.kr/ .

Toward Real-Time Classification of Wake Regimes from Sensor Measurements

NASA Astrophysics Data System (ADS)

Wang, Mengying; Hemati, Maziar S.

2017-11-01

Hydrodynamic signals can transmit information that can be used by marine swimmers to detect disturbances in the local environment. Biological swimmers are able to sense and detect these signals with their hydrodynamic receptor systems. Recently, similar flow sensing systems have been developed with an aim to improve swimming efficiency in human-engineered underwater vehicles. A key part of the sensing strategy is to first classify wake structures in the external fluid, then to execute suitable control actions accordingly. In our previous work, we showed that a variety of 2S and 2P wakes can be distinguished based on time signatures of surface sensor measurements. However, we assumed access to the full dataset. In this talk, we extend our previous findings to classify wake regimes from sensor measurements in real-time, using a recursive Fast Fourier Transform algorithm. Wakes in different dynamical regimes, which may also vary in time, can be distinguished using our approach. Our results provide insights for enhancing hydrodynamic sensory capabilities in human-engineered systems.

CUDASW++ 3.0: accelerating Smith-Waterman protein database search by coupling CPU and GPU SIMD instructions.

PubMed

Liu, Yongchao; Wirawan, Adrianto; Schmidt, Bertil

2013-04-04

The maximal sensitivity for local alignments makes the Smith-Waterman algorithm a popular choice for protein sequence database search based on pairwise alignment. However, the algorithm is compute-intensive due to a quadratic time complexity. Corresponding runtimes are further compounded by the rapid growth of sequence databases. We present CUDASW++ 3.0, a fast Smith-Waterman protein database search algorithm, which couples CPU and GPU SIMD instructions and carries out concurrent CPU and GPU computations. For the CPU computation, this algorithm employs SSE-based vector execution units as accelerators. For the GPU computation, we have investigated for the first time a GPU SIMD parallelization, which employs CUDA PTX SIMD video instructions to gain more data parallelism beyond the SIMT execution model. Moreover, sequence alignment workloads are automatically distributed over CPUs and GPUs based on their respective compute capabilities. Evaluation on the Swiss-Prot database shows that CUDASW++ 3.0 gains a performance improvement over CUDASW++ 2.0 up to 2.9 and 3.2, with a maximum performance of 119.0 and 185.6 GCUPS, on a single-GPU GeForce GTX 680 and a dual-GPU GeForce GTX 690 graphics card, respectively. In addition, our algorithm has demonstrated significant speedups over other top-performing tools: SWIPE and BLAST+. CUDASW++ 3.0 is written in CUDA C++ and PTX assembly languages, targeting GPUs based on the Kepler architecture. This algorithm obtains significant speedups over its predecessor: CUDASW++ 2.0, by benefiting from the use of CPU and GPU SIMD instructions as well as the concurrent execution on CPUs and GPUs. The source code and the simulated data are available at http://cudasw.sourceforge.net.

Juggling with Language Learning Theories. [Videotape

ERIC Educational Resources Information Center

Murphey, Tim

2005-01-01

Learning to juggle has become popular among corporate training programs because it shows participants how to appreciate mistakes and use "Intelligent Fast Failure" (learning quickly by daring to make a lot of simple mistakes at the beginning of a process). Big business also likes the way juggling can get executives "out of the…

Recipients of RTT Aid Struggling

ERIC Educational Resources Information Center

McNeil, Michele

2012-01-01

The 12 winners of the federal Race to the Top competition have experienced near-universal challenges in turning their sweeping, multifaceted proposals into reality, among them a limited state capacity to execute fast, dramatic change and deeply rooted teacher-evaluation systems that have proved hard to transform. Reports unveiled by the U.S.…

Intended actions and unexpected outcomes: automatic and controlled processing in a rapid motor task

PubMed Central

Cheyne, Douglas O.; Ferrari, Paul; Cheyne, James A.

2012-01-01

Human action involves a combination of controlled and automatic behavior. These processes may interact in tasks requiring rapid response selection or inhibition, where temporal constraints preclude timely intervention by conscious, controlled processes over automatized prepotent responses. Such contexts tend to produce frequent errors, but also rapidly executed correct responses, both of which may sometimes be perceived as surprising, unintended, or “automatic”. In order to identify neural processes underlying these two aspects of cognitive control, we measured neuromagnetic brain activity in 12 right-handed subjects during manual responses to rapidly presented digits, with an infrequent target digit that required switching response hand (bimanual task) or response finger (unimanual task). Automaticity of responding was evidenced by response speeding (shorter response times) prior to both failed and fast correct switches. Consistent with this automaticity interpretation of fast correct switches, we observed bilateral motor preparation, as indexed by suppression of beta band (15–30 Hz) oscillations in motor cortex, prior to processing of the switch cue in the bimanual task. In contrast, right frontal theta activity (4–8 Hz) accompanying correct switch responses began after cue onset, suggesting that it reflected controlled inhibition of the default response. Further, this activity was reduced on fast correct switch trials suggesting a more automatic mode of inhibitory control. We also observed post-movement (event-related negativity) ERN-like responses and theta band increases in medial and anterior frontal regions that were significantly larger on error trials, and may reflect a combination of error and delayed inhibitory signals. We conclude that both automatic and controlled processes are engaged in parallel during rapid motor tasks, and that the relative strength and timing of these processes may underlie both optimal task performance and subjective experiences of automaticity or control. PMID:22912612

Motor and Executive Control in Repetitive Timing of Brief Intervals

ERIC Educational Resources Information Center

Holm, Linus; Ullen, Fredrik; Madison, Guy

2013-01-01

We investigated the causal role of executive control functions in the production of brief time intervals by means of a concurrent task paradigm. To isolate the influence of executive functions on timing from motor coordination effects, we dissociated executive load from the number of effectors used in the dual task situation. In 3 experiments,…

The key to success in elite athletes? Explicit and implicit motor learning in youth elite and non-elite soccer players.

PubMed

Verburgh, L; Scherder, E J A; van Lange, P A M; Oosterlaan, J

2016-09-01

In sports, fast and accurate execution of movements is required. It has been shown that implicitly learned movements might be less vulnerable than explicitly learned movements to stressful and fast changing circumstances that exist at the elite sports level. The present study provides insight in explicit and implicit motor learning in youth soccer players with different expertise levels. Twenty-seven youth elite soccer players and 25 non-elite soccer players (aged 10-12) performed a serial reaction time task (SRTT). In the SRTT, one of the sequences must be learned explicitly, the other was implicitly learned. No main effect of group was found for implicit and explicit learning on mean reaction time (MRT) and accuracy. However, for MRT, an interaction was found between learning condition, learning phase and group. Analyses showed no group effects for the explicit learning condition, but youth elite soccer players showed better learning in the implicit learning condition. In particular, during implicit motor learning youth elite soccer showed faster MRTs in the early learning phase and earlier reached asymptote performance in terms of MRT. Present findings may be important for sports because children with superior implicit learning abilities in early learning phases may be able to learn more (durable) motor skills in a shorter time period as compared to other children.

Real-time distributed scheduling algorithm for supporting QoS over WDM networks

NASA Astrophysics Data System (ADS)

Kam, Anthony C.; Siu, Kai-Yeung

1998-10-01

Most existing or proposed WDM networks employ circuit switching, typically with one session having exclusive use of one entire wavelength. Consequently they are not suitable for data applications involving bursty traffic patterns. The MIT AON Consortium has developed an all-optical LAN/MAN testbed which provides time-slotted WDM service and employs fast-tunable transceivers in each optical terminal. In this paper, we explore extensions of this service to achieve fine-grained statistical multiplexing with different virtual circuits time-sharing the wavelengths in a fair manner. In particular, we develop a real-time distributed protocol for best-effort traffic over this time-slotted WDM service with near-optical fairness and throughput characteristics. As an additional design feature, our protocol supports the allocation of guaranteed bandwidths to selected connections. This feature acts as a first step towards supporting integrated services and quality-of-service guarantees over WDM networks. To achieve high throughput, our approach is based on scheduling transmissions, as opposed to collision- based schemes. Our distributed protocol involves one MAN scheduler and several LAN schedulers (one per LAN) in a master-slave arrangement. Because of propagation delays and limits on control channel capacities, all schedulers are designed to work with partial, delayed traffic information. Our distributed protocol is of the `greedy' type to ensure fast execution in real-time in response to dynamic traffic changes. It employs a hybrid form of rate and credit control for resource allocation. We have performed extensive simulations, which show that our protocol allocates resources (transmitters, receivers, wavelengths) fairly with high throughput, and supports bandwidth guarantees.

A novel algorithm for fast grasping of unknown objects using C-shape configuration

NASA Astrophysics Data System (ADS)

Lei, Qujiang; Chen, Guangming; Meijer, Jonathan; Wisse, Martijn

2018-02-01

Increasing grasping efficiency is very important for the robots to grasp unknown objects especially subjected to unfamiliar environments. To achieve this, a new algorithm is proposed based on the C-shape configuration. Specifically, the geometric model of the used under-actuated gripper is approximated as a C-shape. To obtain an appropriate graspable position, this C-shape configuration is applied to fit geometric model of an unknown object. The geometric model of unknown object is constructed by using a single-view partial point cloud. To examine the algorithm using simulations, a comparison of the commonly used motion planners is made. The motion planner with the highest number of solved runs, lowest computing time and the shortest path length is chosen to execute grasps found by this grasping algorithm. The simulation results demonstrate that excellent grasping efficiency is achieved by adopting our algorithm. To validate this algorithm, experiment tests are carried out using a UR5 robot arm and an under-actuated gripper. The experimental results show that steady grasping actions are obtained. Hence, this research provides a novel algorithm for fast grasping of unknown objects.

[Development of a video image system for wireless capsule endoscopes based on DSP].

PubMed

Yang, Li; Peng, Chenglin; Wu, Huafeng; Zhao, Dechun; Zhang, Jinhua

2008-02-01

A video image recorder to record video picture for wireless capsule endoscopes was designed. TMS320C6211 DSP of Texas Instruments Inc. is the core processor of this system. Images are periodically acquired from Composite Video Broadcast Signal (CVBS) source and scaled by video decoder (SAA7114H). Video data is transported from high speed buffer First-in First-out (FIFO) to Digital Signal Processor (DSP) under the control of Complex Programmable Logic Device (CPLD). This paper adopts JPEG algorithm for image coding, and the compressed data in DSP was stored to Compact Flash (CF) card. TMS320C6211 DSP is mainly used for image compression and data transporting. Fast Discrete Cosine Transform (DCT) algorithm and fast coefficient quantization algorithm are used to accelerate operation speed of DSP and decrease the executing code. At the same time, proper address is assigned for each memory, which has different speed;the memory structure is also optimized. In addition, this system uses plenty of Extended Direct Memory Access (EDMA) to transport and process image data, which results in stable and high performance.

The difference engine: a model of diversity in speeded cognition.

PubMed

Myerson, Joel; Hale, Sandra; Zheng, Yingye; Jenkins, Lisa; Widaman, Keith F

2003-06-01

A theory of diversity in speeded cognition, the difference engine, is proposed, in which information processing is represented as a series of generic computational steps. Some individuals tend to perform all of these computations relatively quickly and other individuals tend to perform them all relatively slowly, reflecting the existence of a general cognitive speed factor, but the time required for response selection and execution is assumed to be independent of cognitive speed. The difference engine correctly predicts the positively accelerated form of the relation between diversity of performance, as measured by the standard deviation for the group, and task difficulty, as indexed by the mean response time (RT) for the group. In addition, the difference engine correctly predicts approximately linear relations between the RTs of any individual and average performance for the group, with the regression lines for fast individuals having slopes less than 1.0 (and positive intercepts) and the regression lines for slow individuals having slopes greater than 1.0 (and negative intercepts). Similar predictions are made for comparisons of slow, average, and fast subgroups, regardless of whether those subgroups are formed on the basis of differences in ability, age, or health status. These predictions are consistent with evidence from studies of healthy young and older adults as well as from studies of depressed and age-matched control groups.

LCFM - LIVING COLOR FRAME MAKER: PC GRAPHICS GENERATION AND MANAGEMENT TOOL FOR REAL-TIME APPLICATIONS

NASA Technical Reports Server (NTRS)

Truong, L. V.

1994-01-01

Computer graphics are often applied for better understanding and interpretation of data under observation. These graphics become more complicated when animation is required during "run-time", as found in many typical modern artificial intelligence and expert systems. Living Color Frame Maker is a solution to many of these real-time graphics problems. Living Color Frame Maker (LCFM) is a graphics generation and management tool for IBM or IBM compatible personal computers. To eliminate graphics programming, the graphic designer can use LCFM to generate computer graphics frames. The graphical frames are then saved as text files, in a readable and disclosed format, which can be easily accessed and manipulated by user programs for a wide range of "real-time" visual information applications. For example, LCFM can be implemented in a frame-based expert system for visual aids in management of systems. For monitoring, diagnosis, and/or controlling purposes, circuit or systems diagrams can be brought to "life" by using designated video colors and intensities to symbolize the status of hardware components (via real-time feedback from sensors). Thus status of the system itself can be displayed. The Living Color Frame Maker is user friendly with graphical interfaces, and provides on-line help instructions. All options are executed using mouse commands and are displayed on a single menu for fast and easy operation. LCFM is written in C++ using the Borland C++ 2.0 compiler for IBM PC series computers and compatible computers running MS-DOS. The program requires a mouse and an EGA/VGA display. A minimum of 77K of RAM is also required for execution. The documentation is provided in electronic form on the distribution medium in WordPerfect format. A sample MS-DOS executable is provided on the distribution medium. The standard distribution medium for this program is one 5.25 inch 360K MS-DOS format diskette. The contents of the diskette are compressed using the PKWARE archiving tools. The utility to unarchive the files, PKUNZIP.EXE, is included. The Living Color Frame Maker tool was developed in 1992.

Reconstruction for time-domain in vivo EPR 3D multigradient oximetric imaging--a parallel processing perspective.

PubMed

Dharmaraj, Christopher D; Thadikonda, Kishan; Fletcher, Anthony R; Doan, Phuc N; Devasahayam, Nallathamby; Matsumoto, Shingo; Johnson, Calvin A; Cook, John A; Mitchell, James B; Subramanian, Sankaran; Krishna, Murali C

2009-01-01

Three-dimensional Oximetric Electron Paramagnetic Resonance Imaging using the Single Point Imaging modality generates unpaired spin density and oxygen images that can readily distinguish between normal and tumor tissues in small animals. It is also possible with fast imaging to track the changes in tissue oxygenation in response to the oxygen content in the breathing air. However, this involves dealing with gigabytes of data for each 3D oximetric imaging experiment involving digital band pass filtering and background noise subtraction, followed by 3D Fourier reconstruction. This process is rather slow in a conventional uniprocessor system. This paper presents a parallelization framework using OpenMP runtime support and parallel MATLAB to execute such computationally intensive programs. The Intel compiler is used to develop a parallel C++ code based on OpenMP. The code is executed on four Dual-Core AMD Opteron shared memory processors, to reduce the computational burden of the filtration task significantly. The results show that the parallel code for filtration has achieved a speed up factor of 46.66 as against the equivalent serial MATLAB code. In addition, a parallel MATLAB code has been developed to perform 3D Fourier reconstruction. Speedup factors of 4.57 and 4.25 have been achieved during the reconstruction process and oximetry computation, for a data set with 23 x 23 x 23 gradient steps. The execution time has been computed for both the serial and parallel implementations using different dimensions of the data and presented for comparison. The reported system has been designed to be easily accessible even from low-cost personal computers through local internet (NIHnet). The experimental results demonstrate that the parallel computing provides a source of high computational power to obtain biophysical parameters from 3D EPR oximetric imaging, almost in real-time.

Computer Simulation Results for the Two-Point Probability Function of Composite Media

NASA Astrophysics Data System (ADS)

Smith, P.; Torquato, S.

1988-05-01

Computer simulation results are reported for the two-point matrix probability function S2 of two-phase random media composed of disks distributed with an arbitrary degree of impenetrability λ. The novel technique employed to sample S2( r) (which gives the probability of finding the endpoints of a line segment of length r in the matrix) is very accurate and has a fast execution time. Results for the limiting cases λ = 0 (fully penetrable disks) and λ = 1 (hard disks), respectively, compare very favorably with theoretical predictions made by Torquato and Beasley and by Torquato and Lado. Results are also reported for several values of λ. that lie between these two extremes: cases which heretofore have not been examined.

Barista: A Framework for Concurrent Speech Processing by USC-SAIL

PubMed Central

Can, Doğan; Gibson, James; Vaz, Colin; Georgiou, Panayiotis G.; Narayanan, Shrikanth S.

2016-01-01

We present Barista, an open-source framework for concurrent speech processing based on the Kaldi speech recognition toolkit and the libcppa actor library. With Barista, we aim to provide an easy-to-use, extensible framework for constructing highly customizable concurrent (and/or distributed) networks for a variety of speech processing tasks. Each Barista network specifies a flow of data between simple actors, concurrent entities communicating by message passing, modeled after Kaldi tools. Leveraging the fast and reliable concurrency and distribution mechanisms provided by libcppa, Barista lets demanding speech processing tasks, such as real-time speech recognizers and complex training workflows, to be scheduled and executed on parallel (and/or distributed) hardware. Barista is released under the Apache License v2.0. PMID:27610047

Barista: A Framework for Concurrent Speech Processing by USC-SAIL.

PubMed

Can, Doğan; Gibson, James; Vaz, Colin; Georgiou, Panayiotis G; Narayanan, Shrikanth S

2014-05-01

We present Barista, an open-source framework for concurrent speech processing based on the Kaldi speech recognition toolkit and the libcppa actor library. With Barista, we aim to provide an easy-to-use, extensible framework for constructing highly customizable concurrent (and/or distributed) networks for a variety of speech processing tasks. Each Barista network specifies a flow of data between simple actors, concurrent entities communicating by message passing, modeled after Kaldi tools. Leveraging the fast and reliable concurrency and distribution mechanisms provided by libcppa, Barista lets demanding speech processing tasks, such as real-time speech recognizers and complex training workflows, to be scheduled and executed on parallel (and/or distributed) hardware. Barista is released under the Apache License v2.0.

Strength-balance supplemented with computerized cognitive training to improve dual task gait and divided attention in older adults: a multicenter randomized-controlled trial.

PubMed

van het Reve, Eva; de Bruin, Eling D

2014-12-15

Exercise interventions often do not combine physical and cognitive training. However, this combination is assumed to be more beneficial in improving walking and cognitive functioning compared to isolated cognitive or physical training. A multicenter parallel randomized controlled trial was conducted to compare a motor to a cognitive-motor exercise program. A total of 182 eligible residents of homes-for-the-aged (n = 159) or elderly living in the vicinity of the homes (n = 23) were randomly assigned to either strength-balance (SB) or strength-balance-cognitive (SBC) training. Both groups conducted similar strength-balance training during 12 weeks. SBC additionally absolved computerized cognitive training. Outcomes were dual task costs of walking, physical performance, simple reaction time, executive functions, divided attention, fear of falling and fall rate. Participants were analysed with an intention to treat approach. The 182 participants (mean age ± SD: 81.5 ± 7.3 years) were allocated to either SB (n = 98) or SBC (n = 84). The attrition rate was 14.3%. Interaction effects were observed for dual task costs of step length (preferred walking speed: F(1,174) = 4.94, p = 0.028, η2 = 0.027, fast walking speed: F(1,166) = 6.14, p = 0.009, η2 = 0.040) and dual task costs of the standard deviation of step length (F(1,166) = 6.14, p = 0.014, η2 = 0.036), in favor of SBC. Significant interactions in favor of SBC revealed for in gait initiation (F(1,166) = 9.16, p = 0.003, η2 = 0.052), 'reaction time' (F(1,180) = 5.243, p = 0.023, η² = 0.028) & 'missed answers' (F(1,180) = 11.839, p = 0.001, η² = 0.062) as part of the test for divided attention. Within-group comparison revealed significant improvements in dual task costs of walking (preferred speed; velocity (p = 0.002), step time (p = 0.018), step length (p = 0.028), fast speed; velocity (p < 0.001), step time (p = 0.035), step length (p = 0.001)), simple reaction time (p < 0.001), executive functioning (Trail making test B; p < 0.001), divided attention (p < 0.001), fear of falling (p < 0.001), and fall rate (p < 0.001). Combining strength-balance training with specific cognitive training has a positive additional effect on dual task costs of walking, gait initiation, and divided attention. The findings further confirm previous research showing that strength-balance training improves executive functions and reduces falls. This trial has been registered under ISRCTN75134517.

PLAT: An Automated Fault and Behavioural Anomaly Detection Tool for PLC Controlled Manufacturing Systems.

PubMed

Ghosh, Arup; Qin, Shiming; Lee, Jooyeoun; Wang, Gi-Nam

2016-01-01

Operational faults and behavioural anomalies associated with PLC control processes take place often in a manufacturing system. Real time identification of these operational faults and behavioural anomalies is necessary in the manufacturing industry. In this paper, we present an automated tool, called PLC Log-Data Analysis Tool (PLAT) that can detect them by using log-data records of the PLC signals. PLAT automatically creates a nominal model of the PLC control process and employs a novel hash table based indexing and searching scheme to satisfy those purposes. Our experiments show that PLAT is significantly fast, provides real time identification of operational faults and behavioural anomalies, and can execute within a small memory footprint. In addition, PLAT can easily handle a large manufacturing system with a reasonable computing configuration and can be installed in parallel to the data logging system to identify operational faults and behavioural anomalies effectively.

PLAT: An Automated Fault and Behavioural Anomaly Detection Tool for PLC Controlled Manufacturing Systems

PubMed Central

Ghosh, Arup; Qin, Shiming; Lee, Jooyeoun

2016-01-01

Operational faults and behavioural anomalies associated with PLC control processes take place often in a manufacturing system. Real time identification of these operational faults and behavioural anomalies is necessary in the manufacturing industry. In this paper, we present an automated tool, called PLC Log-Data Analysis Tool (PLAT) that can detect them by using log-data records of the PLC signals. PLAT automatically creates a nominal model of the PLC control process and employs a novel hash table based indexing and searching scheme to satisfy those purposes. Our experiments show that PLAT is significantly fast, provides real time identification of operational faults and behavioural anomalies, and can execute within a small memory footprint. In addition, PLAT can easily handle a large manufacturing system with a reasonable computing configuration and can be installed in parallel to the data logging system to identify operational faults and behavioural anomalies effectively. PMID:27974882

A space-efficient quantum computer simulator suitable for high-speed FPGA implementation

NASA Astrophysics Data System (ADS)

Frank, Michael P.; Oniciuc, Liviu; Meyer-Baese, Uwe H.; Chiorescu, Irinel

2009-05-01

Conventional vector-based simulators for quantum computers are quite limited in the size of the quantum circuits they can handle, due to the worst-case exponential growth of even sparse representations of the full quantum state vector as a function of the number of quantum operations applied. However, this exponential-space requirement can be avoided by using general space-time tradeoffs long known to complexity theorists, which can be appropriately optimized for this particular problem in a way that also illustrates some interesting reformulations of quantum mechanics. In this paper, we describe the design and empirical space/time complexity measurements of a working software prototype of a quantum computer simulator that avoids excessive space requirements. Due to its space-efficiency, this design is well-suited to embedding in single-chip environments, permitting especially fast execution that avoids access latencies to main memory. We plan to prototype our design on a standard FPGA development board.

Formulation of the rotational transformation of wave fields and their application to digital holography.

PubMed

Matsushima, Kyoji

2008-07-01

Rotational transformation based on coordinate rotation in Fourier space is a useful technique for simulating wave field propagation between nonparallel planes. This technique is characterized by fast computation because the transformation only requires executing a fast Fourier transform twice and a single interpolation. It is proved that the formula of the rotational transformation mathematically satisfies the Helmholtz equation. Moreover, to verify the formulation and its usefulness in wave optics, it is also demonstrated that the transformation makes it possible to reconstruct an image on arbitrarily tilted planes from a wave field captured experimentally by using digital holography.

Daily modulation of the speed-accuracy trade-off.

PubMed

Gueugneau, Nicolas; Pozzo, Thierry; Darlot, Christian; Papaxanthis, Charalambos

2017-07-25

Goal-oriented arm movements are characterized by a balance between speed and accuracy. The relation between speed and accuracy has been formalized by Fitts' law and predicts a linear increase in movement duration with task constraints. Up to now this relation has been investigated on a short-time scale only, that is during a single experimental session, although chronobiological studies report that the motor system is shaped by circadian rhythms. Here, we examine whether the speed-accuracy trade-off could vary during the day. Healthy adults carried out arm-pointing movements as accurately and fast as possible toward targets of different sizes at various hours of the day, and variations in Fitts' law parameters were scrutinized. To investigate whether the potential modulation of the speed-accuracy trade-off has peripheral and/or central origins, a motor imagery paradigm was used as well. Results indicated a daily (circadian-like) variation for the durations of both executed and mentally simulated movements, in strictly controlled accuracy conditions. While Fitts' law was held for the whole sessions of the day, the slope of the relation between movement duration and task difficulty expressed a clear modulation, with the lowest values in the afternoon. This variation of the speed-accuracy trade-off in executed and mental movements suggests that, beyond execution parameters, motor planning mechanisms are modulated during the day. Daily update of forward models is discussed as a potential mechanism. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Influence of stimulant medication and response speed on lateralization of movement-related potentials in attention-deficit/hyperactivity disorder.

PubMed

Bender, Stephan; Resch, Franz; Klein, Christoph; Renner, Tobias; Fallgatter, Andreas J; Weisbrod, Matthias; Romanos, Marcel

2012-01-01

Hyperactivity is one of the core symptoms in attention deficit hyperactivity disorder (ADHD). However, it remains unclear in which way the motor system itself and its development are affected by the disorder. Movement-related potentials (MRP) can separate different stages of movement execution, from the programming of a movement to motor post-processing and memory traces. Pre-movement MRP are absent or positive during early childhood and display a developmental increase of negativity. We examined the influences of response-speed, an indicator of the level of attention, and stimulant medication on lateralized MRP in 16 children with combined type ADHD compared to 20 matched healthy controls. We detected a significantly diminished lateralisation of MRP over the pre-motor and primary motor cortex during movement execution (initial motor potential peak, iMP) in patients with ADHD. Fast reactions (indicating increased visuo-motor attention) led to increased lateralized negativity during movement execution only in healthy controls, while in children with ADHD faster reaction times were associated with more positive amplitudes. Even though stimulant medication had some effect on attenuating group differences in lateralized MRP, this effect was insufficient to normalize lateralized iMP amplitudes. A reduced focal (lateralized) motor cortex activation during the command to muscle contraction points towards an immature motor system and a maturation delay of the (pre-) motor cortex in children with ADHD. A delayed maturation of the neuronal circuitry, which involves primary motor cortex, may contribute to ADHD pathophysiology.

Safe teleoperation based on flexible intraoperative planning for robot-assisted laser microsurgery.

PubMed

Mattos, Leonardo S; Caldwell, Darwin G

2012-01-01

This paper describes a new intraoperative planning system created to improve precision and safety in teleoperated laser microsurgeries. It addresses major safety issues related to real-time control of a surgical laser during teleoperated procedures, which are related to the reliability and robustness of the telecommunication channels. Here, a safe solution is presented, consisting in a new planning system architecture that maintains the flexibility and benefits of real-time teleoperation and keeps the surgeon in control of all surgical actions. The developed system is based on our virtual scalpel system for robot-assisted laser microsurgery, and allows the intuitive use of stylus to create surgical plans directly over live video of the surgical field. In this case, surgical plans are defined as graphic objects overlaid on the live video, which can be easily modified or replaced as needed, and which are transmitted to the main surgical system controller for subsequent safe execution. In the process of improving safety, this new planning system also resulted in improved laser aiming precision and improved capability for higher quality laser procedures, both due to the new surgical plan execution module, which allows very fast and precise laser aiming control. Experimental results presented herein show that, in addition to the safety improvements, the new planning system resulted in a 48% improvement in laser aiming precision when compared to the previous virtual scalpel system.

Two-dimensional systolic-array architecture for pixel-level vision tasks

NASA Astrophysics Data System (ADS)

Vijverberg, Julien A.; de With, Peter H. N.

2010-05-01

This paper presents ongoing work on the design of a two-dimensional (2D) systolic array for image processing. This component is designed to operate on a multi-processor system-on-chip. In contrast with other 2D systolic-array architectures and many other hardware accelerators, we investigate the applicability of executing multiple tasks in a time-interleaved fashion on the Systolic Array (SA). This leads to a lower external memory bandwidth and better load balancing of the tasks on the different processing tiles. To enable the interleaving of tasks, we add a shadow-state register for fast task switching. To reduce the number of accesses to the external memory, we propose to share the communication assist between consecutive tasks. A preliminary, non-functional version of the SA has been synthesized for an XV4S25 FPGA device and yields a maximum clock frequency of 150 MHz requiring 1,447 slices and 5 memory blocks. Mapping tasks from video content-analysis applications from literature on the SA yields reductions in the execution time of 1-2 orders of magnitude compared to the software implementation. We conclude that the choice for an SA architecture is useful, but a scaled version of the SA featuring less logic with fewer processing and pipeline stages yielding a lower clock frequency, would be sufficient for a video analysis system-on-chip.

MutScan: fast detection and visualization of target mutations by scanning FASTQ data.

PubMed

Chen, Shifu; Huang, Tanxiao; Wen, Tiexiang; Li, Hong; Xu, Mingyan; Gu, Jia

2018-01-22

Some types of clinical genetic tests, such as cancer testing using circulating tumor DNA (ctDNA), require sensitive detection of known target mutations. However, conventional next-generation sequencing (NGS) data analysis pipelines typically involve different steps of filtering, which may cause miss-detection of key mutations with low frequencies. Variant validation is also indicated for key mutations detected by bioinformatics pipelines. Typically, this process can be executed using alignment visualization tools such as IGV or GenomeBrowse. However, these tools are too heavy and therefore unsuitable for validating mutations in ultra-deep sequencing data. We developed MutScan to address problems of sensitive detection and efficient validation for target mutations. MutScan involves highly optimized string-searching algorithms, which can scan input FASTQ files to grab all reads that support target mutations. The collected supporting reads for each target mutation will be piled up and visualized using web technologies such as HTML and JavaScript. Algorithms such as rolling hash and bloom filter are applied to accelerate scanning and make MutScan applicable to detect or visualize target mutations in a very fast way. MutScan is a tool for the detection and visualization of target mutations by only scanning FASTQ raw data directly. Compared to conventional pipelines, this offers a very high performance, executing about 20 times faster, and offering maximal sensitivity since it can grab mutations with even one single supporting read. MutScan visualizes detected mutations by generating interactive pile-ups using web technologies. These can serve to validate target mutations, thus avoiding false positives. Furthermore, MutScan can visualize all mutation records in a VCF file to HTML pages for cloud-friendly VCF validation. MutScan is an open source tool available at GitHub: https://github.com/OpenGene/MutScan.

Modelling Limit Order Execution Times from Market Data

NASA Astrophysics Data System (ADS)

Kim, Adlar; Farmer, Doyne; Lo, Andrew

2007-03-01

Although the term ``liquidity'' is widely used in finance literatures, its meaning is very loosely defined and there is no quantitative measure for it. Generally, ``liquidity'' means an ability to quickly trade stocks without causing a significant impact on the stock price. From this definition, we identified two facets of liquidity -- 1.execution time of limit orders, and 2.price impact of market orders. The limit order is an order to transact a prespecified number of shares at a prespecified price, which will not cause an immediate execution. On the other hand, the market order is an order to transact a prespecified number of shares at a market price, which will cause an immediate execution, but are subject to price impact. Therefore, when the stock is liquid, market participants will experience quick limit order executions and small market order impacts. As a first step to understand market liquidity, we studied the facet of liquidity related to limit order executions -- execution times. In this talk, we propose a novel approach of modeling limit order execution times and show how they are affected by size and price of orders. We used q-Weibull distribution, which is a generalized form of Weibull distribution that can control the fatness of tail to model limit order execution times.

cljam: a library for handling DNA sequence alignment/map (SAM) with parallel processing.

PubMed

Takeuchi, Toshiki; Yamada, Atsuo; Aoki, Takashi; Nishimura, Kunihiro

2016-01-01

Next-generation sequencing can determine DNA bases and the results of sequence alignments are generally stored in files in the Sequence Alignment/Map (SAM) format and the compressed binary version (BAM) of it. SAMtools is a typical tool for dealing with files in the SAM/BAM format. SAMtools has various functions, including detection of variants, visualization of alignments, indexing, extraction of parts of the data and loci, and conversion of file formats. It is written in C and can execute fast. However, SAMtools requires an additional implementation to be used in parallel with, for example, OpenMP (Open Multi-Processing) libraries. For the accumulation of next-generation sequencing data, a simple parallelization program, which can support cloud and PC cluster environments, is required. We have developed cljam using the Clojure programming language, which simplifies parallel programming, to handle SAM/BAM data. Cljam can run in a Java runtime environment (e.g., Windows, Linux, Mac OS X) with Clojure. Cljam can process and analyze SAM/BAM files in parallel and at high speed. The execution time with cljam is almost the same as with SAMtools. The cljam code is written in Clojure and has fewer lines than other similar tools.

The effect of executive function on stress, depression, anxiety, and quality of life in multiple sclerosis.

PubMed

Grech, Lisa B; Kiropoulos, Litza A; Kirby, Katherine M; Butler, Ernest; Paine, Mark; Hester, Robert

2015-01-01

The experience of cognitive deficits and emotional dysfunction are prevalent in people with multiple sclerosis (PwMS), although research examining their interaction has provided inconsistent findings. The current study examined the ability of executive function to predict psychosocial adjustment in PwMS. One hundred and seven PwMS underwent cognitive assessment and completed measures of stress, depression, anxiety, and quality of life (QoL). There was limited support for a relationship. There was no relationship between objective cognitive tasks and state or trait anxiety, mental health QoL, overall QoL, or stress frequency. The only relationship with depression was found when the Beck Depression Inventory Fast-Screen was used, with a task of planning when the timing element was removed. A measure of error rates on a task of cognitive flexibility predicted physical health QoL, and severity, but not frequency, of stress was predicted by a task of working memory. The results of this study highlight the need for further research into the relationship between cognitive deficits and psychosocial adjustment because of the conflicting findings between studies and call for a common measurement framework for future investigation.

Reduced variability and execution time to reach a target with a needle GPS system: Comparison between physicians, residents and nurse anaesthetists.

PubMed

Fevre, Marie-Cécile; Vincent, Caroline; Picard, Julien; Vighetti, Arnaud; Chapuis, Claire; Detavernier, Maxime; Allenet, Benoît; Payen, Jean-François; Bosson, Jean-Luc; Albaladejo, Pierre

2018-02-01

Ultrasound (US) guided needle positioning is safer than anatomical landmark techniques for central venous access. Hand-eye coordination and execution time depend on the professional's ability, previous training and personal skills. Needle guidance positioning systems (GPS) may theoretically reduce execution time and facilitate needle positioning in specific targets, thus improving patient comfort and safety. Three groups of healthcare professionals (41 anaesthesiologists and intensivists, 41 residents in anaesthesiology and intensive care, 39 nurse anaesthetists) were included and required to perform 3 tasks (positioning the tip of a needle in three different targets in a silicon phantom) by using successively a conventional US-guided needle positioning and a needle GPS. We measured execution times to perform the tasks, hand-eye coordination and the number of repositioning occurrences or errors in handling the needle or the probe. Without the GPS system, we observed a significant inter-individual difference for execution time (P<0.05), hand-eye coordination and the number of errors/needle repositioning between physicians, residents and nurse anaesthetists. US training and video gaming were found to be independent factors associated with a shorter execution time. Use of GPS attenuated the inter-individual and group variability. We observed a reduced execution time and improved hand-eye coordination in all groups as compared to US without GPS. Neither US training, video gaming nor demographic personal or professional factors were found to be significantly associated with reduced execution time when GPS was used. US associated with GPS systems may improve safety and decrease execution time by reducing inter-individual variability between professionals for needle-handling procedures. Copyright © 2016 Société française d'anesthésie et de réanimation (Sfar). Published by Elsevier Masson SAS. All rights reserved.

Obstacle Detection Algorithms for Aircraft Navigation: Performance Characterization of Obstacle Detection Algorithms for Aircraft Navigation

NASA Technical Reports Server (NTRS)

Kasturi, Rangachar; Camps, Octavia; Coraor, Lee

2000-01-01

The research reported here is a part of NASA's Synthetic Vision System (SVS) project for the development of a High Speed Civil Transport Aircraft (HSCT). One of the components of the SVS is a module for detection of potential obstacles in the aircraft's flight path by analyzing the images captured by an on-board camera in real-time. Design of such a module includes the selection and characterization of robust, reliable, and fast techniques and their implementation for execution in real-time. This report describes the results of our research in realizing such a design. It is organized into three parts. Part I. Data modeling and camera characterization; Part II. Algorithms for detecting airborne obstacles; and Part III. Real time implementation of obstacle detection algorithms on the Datacube MaxPCI architecture. A list of publications resulting from this grant as well as a list of relevant publications resulting from prior NASA grants on this topic are presented.

A direct-execution parallel architecture for the Advanced Continuous Simulation Language (ACSL)

NASA Technical Reports Server (NTRS)

Carroll, Chester C.; Owen, Jeffrey E.

1988-01-01

A direct-execution parallel architecture for the Advanced Continuous Simulation Language (ACSL) is presented which overcomes the traditional disadvantages of simulations executed on a digital computer. The incorporation of parallel processing allows the mapping of simulations into a digital computer to be done in the same inherently parallel manner as they are currently mapped onto an analog computer. The direct-execution format maximizes the efficiency of the executed code since the need for a high level language compiler is eliminated. Resolution is greatly increased over that which is available with an analog computer without the sacrifice in execution speed normally expected with digitial computer simulations. Although this report covers all aspects of the new architecture, key emphasis is placed on the processing element configuration and the microprogramming of the ACLS constructs. The execution times for all ACLS constructs are computed using a model of a processing element based on the AMD 29000 CPU and the AMD 29027 FPU. The increase in execution speed provided by parallel processing is exemplified by comparing the derived execution times of two ACSL programs with the execution times for the same programs executed on a similar sequential architecture.

Statistical fingerprinting for malware detection and classification

DOEpatents

Prowell, Stacy J.; Rathgeb, Christopher T.

2015-09-15

A system detects malware in a computing architecture with an unknown pedigree. The system includes a first computing device having a known pedigree and operating free of malware. The first computing device executes a series of instrumented functions that, when executed, provide a statistical baseline that is representative of the time it takes the software application to run on a computing device having a known pedigree. A second computing device executes a second series of instrumented functions that, when executed, provides an actual time that is representative of the time the known software application runs on the second computing device. The system detects malware when there is a difference in execution times between the first and the second computing devices.

Adaptations of Prefrontal Brain Activity, Executive Functions, and Gait in Healthy Elderly Following Exergame and Balance Training: A Randomized-Controlled Study

PubMed Central

Schättin, Alexandra; Arner, Rendel; Gennaro, Federico; de Bruin, Eling D.

2016-01-01

During aging, the prefrontal cortex (PFC) undergoes age-dependent neuronal changes influencing cognitive and motor functions. Motor-learning interventions are hypothesized to ameliorate motor and cognitive deficits in older adults. Especially, video game-based physical exercise might have the potential to train motor in combination with cognitive abilities in older adults. The aim of this study was to compare conventional balance training with video game-based physical exercise, a so-called exergame, on the relative power (RP) of electroencephalographic (EEG) frequencies over the PFC, executive function (EF), and gait performance. Twenty-seven participants (mean age 79.2 ± 7.3 years) were randomly assigned to one of two groups. All participants completed 24 trainings including three times a 30 min session/week. The EEG measurements showed that theta RP significantly decreased in favor of the exergame group [L(14) = 6.23, p = 0.007]. Comparing pre- vs. post-test, EFs improved both within the exergame (working memory: z = −2.28, p = 0.021; divided attention auditory: z = −2.51, p = 0.009; divided attention visual: z = −2.06, p = 0.040; go/no-go: z = −2.55, p = 0.008; set-shifting: z = −2.90, p = 0.002) and within the balance group (set-shifting: z = −2.04, p = 0.042). Moreover, spatio-temporal gait parameters primarily improved within the exergame group under dual-task conditions (speed normal walking: z = −2.90, p = 0.002; speed fast walking: z = −2.97, p = 0.001; cadence normal walking: z = −2.97, p = 0.001; stride length fast walking: z = −2.69, p = 0.005) and within the balance group under single-task conditions (speed normal walking: z = −2.54, p = 0.009; speed fast walking: z = −1.98, p = 0.049; cadence normal walking: z = −2.79, p = 0.003). These results indicate that exergame training as well as balance training positively influence prefrontal cortex activity and/or function in varying proportion. PMID:27932975

Robust feature estimation by non-rigid hierarchical image registration and its application in disparity measurement

NASA Astrophysics Data System (ADS)

Badshah, Amir; Choudhry, Aadil Jaleel; Ullah, Shan

2017-03-01

Industries are moving towards automation in order to increase productivity and ensure quality. Variety of electronic and electromagnetic systems are being employed to assist human operator in fast and accurate quality inspection of products. Majority of these systems are equipped with cameras and rely on diverse image processing algorithms. Information is lost in 2D image, therefore acquiring accurate 3D data from 2D images is an open issue. FAST, SURF and SIFT are well-known spatial domain techniques for features extraction and henceforth image registration to find correspondence between images. The efficiency of these methods is measured in terms of the number of perfect matches found. A novel fast and robust technique for stereo-image processing is proposed. It is based on non-rigid registration using modified normalized phase correlation. The proposed method registers two images in hierarchical fashion using quad-tree structure. The registration process works through global to local level resulting in robust matches even in presence of blur and noise. The computed matches can further be utilized to determine disparity and depth for industrial product inspection. The same can be used in driver assistance systems. The preliminary tests on Middlebury dataset produced satisfactory results. The execution time for a 413 x 370 stereo-pair is 500ms approximately on a low cost DSP.

Fast Neural Solution Of A Nonlinear Wave Equation

NASA Technical Reports Server (NTRS)

Barhen, Jacob; Toomarian, Nikzad

1996-01-01

Neural algorithm for simulation of class of nonlinear wave phenomena devised. Numerically solves special one-dimensional case of Korteweg-deVries equation. Intended to be executed rapidly by neural network implemented as charge-coupled-device/charge-injection device, very-large-scale integrated-circuit analog data processor of type described in "CCD/CID Processors Would Offer Greater Precision" (NPO-18972).

77 FR 42780 - Self-Regulatory Organizations; NASDAQ OMX PHLX LLC; Notice of Filing of Proposed Rule Change...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-20

... strategies effectively via STOs,\\8\\ particularly in the current fast and volatile multi-faceted trading and... proposal, to allow execution of more effective trading and hedging strategies on the Exchange. See... strategies on the Exchange. The Exchange believes that this precision is increasingly necessary, and in fact...

Exploring Liquid Sequential Injection Chromatography to Teach Fundamentals of Separation Methods: A Very Fast Analytical Chemistry Experiment

ERIC Educational Resources Information Center

Penteado, Jose C.; Masini, Jorge Cesar

2011-01-01

Influence of the solvent strength determined by the addition of a mobile-phase organic modifier and pH on chromatographic separation of sorbic acid and vanillin has been investigated by the relatively new technique, liquid sequential injection chromatography (SIC). This technique uses reversed-phase monolithic stationary phase to execute fast…

Turbo-Satori: a neurofeedback and brain-computer interface toolbox for real-time functional near-infrared spectroscopy.

PubMed

Lührs, Michael; Goebel, Rainer

2017-10-01

Turbo-Satori is a neurofeedback and brain-computer interface (BCI) toolbox for real-time functional near-infrared spectroscopy (fNIRS). It incorporates multiple pipelines from real-time preprocessing and analysis to neurofeedback and BCI applications. The toolbox is designed with a focus in usability, enabling a fast setup and execution of real-time experiments. Turbo-Satori uses an incremental recursive least-squares procedure for real-time general linear model calculation and support vector machine classifiers for advanced BCI applications. It communicates directly with common NIRx fNIRS hardware and was tested extensively ensuring that the calculations can be performed in real time without a significant change in calculation times for all sampling intervals during ongoing experiments of up to 6 h of recording. Enabling immediate access to advanced processing features also allows the use of this toolbox for students and nonexperts in the field of fNIRS data acquisition and processing. Flexible network interfaces allow third party stimulus applications to access the processed data and calculated statistics in real time so that this information can be easily incorporated in neurofeedback or BCI presentations.

ADHD symptoms and benefit from extended time testing accommodations.

PubMed

Lovett, Benjamin J; Leja, Ashley M

2015-02-01

To investigate the relationship between ADHD symptoms, executive functioning problems, and benefit from extended time testing accommodations. College students completed a battery of measures assessing processing speed and reading fluency, reading comprehension (under two different time limits), symptoms of ADHD, executive functioning deficits, and perceptions of need for extended time. Students reporting more symptoms of ADHD and executive functioning deficits actually benefited less from extended time, and students' perceptions of their timing needs did not predict benefit. Students with more ADHD symptoms are less likely to use extended time effectively, possibly because of their associated executive functioning problems. These results suggest there may be little justification for examining a student's ADHD symptoms when making extended time accommodation decisions. © 2013 SAGE Publications.

FAST User Guide

NASA Technical Reports Server (NTRS)

Walatka, Pamela P.; Clucas, Jean; McCabe, R. Kevin; Plessel, Todd; Potter, R.; Cooper, D. M. (Technical Monitor)

1994-01-01

The Flow Analysis Software Toolkit, FAST, is a software environment for visualizing data. FAST is a collection of separate programs (modules) that run simultaneously and allow the user to examine the results of numerical and experimental simulations. The user can load data files, perform calculations on the data, visualize the results of these calculations, construct scenes of 3D graphical objects, and plot, animate and record the scenes. Computational Fluid Dynamics (CFD) visualization is the primary intended use of FAST, but FAST can also assist in the analysis of other types of data. FAST combines the capabilities of such programs as PLOT3D, RIP, SURF, and GAS into one environment with modules that share data. Sharing data between modules eliminates the drudgery of transferring data between programs. All the modules in the FAST environment have a consistent, highly interactive graphical user interface. Most commands are entered by pointing and'clicking. The modular construction of FAST makes it flexible and extensible. The environment can be custom configured and new modules can be developed and added as needed. The following modules have been developed for FAST: VIEWER, FILE IO, CALCULATOR, SURFER, TOPOLOGY, PLOTTER, TITLER, TRACER, ARCGRAPH, GQ, SURFERU, SHOTET, and ISOLEVU. A utility is also included to make the inclusion of user defined modules in the FAST environment easy. The VIEWER module is the central control for the FAST environment. From VIEWER, the user can-change object attributes, interactively position objects in three-dimensional space, define and save scenes, create animations, spawn new FAST modules, add additional view windows, and save and execute command scripts. The FAST User Guide uses text and FAST MAPS (graphical representations of the entire user interface) to guide the user through the use of FAST. Chapters include: Maps, Overview, Tips, Getting Started Tutorial, a separate chapter for each module, file formats, and system administration.

Sub-Second Parallel State Estimation

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

Chen, Yousu; Rice, Mark J.; Glaesemann, Kurt R.

This report describes the performance of Pacific Northwest National Laboratory (PNNL) sub-second parallel state estimation (PSE) tool using the utility data from the Bonneville Power Administrative (BPA) and discusses the benefits of the fast computational speed for power system applications. The test data were provided by BPA. They are two-days’ worth of hourly snapshots that include power system data and measurement sets in a commercial tool format. These data are extracted out from the commercial tool box and fed into the PSE tool. With the help of advanced solvers, the PSE tool is able to solve each BPA hourly statemore » estimation problem within one second, which is more than 10 times faster than today’s commercial tool. This improved computational performance can help increase the reliability value of state estimation in many aspects: (1) the shorter the time required for execution of state estimation, the more time remains for operators to take appropriate actions, and/or to apply automatic or manual corrective control actions. This increases the chances of arresting or mitigating the impact of cascading failures; (2) the SE can be executed multiple times within time allowance. Therefore, the robustness of SE can be enhanced by repeating the execution of the SE with adaptive adjustments, including removing bad data and/or adjusting different initial conditions to compute a better estimate within the same time as a traditional state estimator’s single estimate. There are other benefits with the sub-second SE, such as that the PSE results can potentially be used in local and/or wide-area automatic corrective control actions that are currently dependent on raw measurements to minimize the impact of bad measurements, and provides opportunities to enhance the power grid reliability and efficiency. PSE also can enable other advanced tools that rely on SE outputs and could be used to further improve operators’ actions and automated controls to mitigate effects of severe events on the grid. The power grid continues to grow and the number of measurements is increasing at an accelerated rate due to the variety of smart grid devices being introduced. A parallel state estimation implementation will have better performance than traditional, sequential state estimation by utilizing the power of high performance computing (HPC). This increased performance positions parallel state estimators as valuable tools for operating the increasingly more complex power grid.« less

Selecting and Improving Quasi-Experimental Designs in Effectiveness and Implementation Research.

PubMed

Handley, Margaret A; Lyles, Courtney R; McCulloch, Charles; Cattamanchi, Adithya

2018-04-01

Interventional researchers face many design challenges when assessing intervention implementation in real-world settings. Intervention implementation requires holding fast on internal validity needs while incorporating external validity considerations (such as uptake by diverse subpopulations, acceptability, cost, and sustainability). Quasi-experimental designs (QEDs) are increasingly employed to achieve a balance between internal and external validity. Although these designs are often referred to and summarized in terms of logistical benefits, there is still uncertainty about (a) selecting from among various QEDs and (b) developing strategies to strengthen the internal and external validity of QEDs. We focus here on commonly used QEDs (prepost designs with nonequivalent control groups, interrupted time series, and stepped-wedge designs) and discuss several variants that maximize internal and external validity at the design, execution and implementation, and analysis stages.

Liborg: a lidar-based robot for efficient 3D mapping

NASA Astrophysics Data System (ADS)

Vlaminck, Michiel; Luong, Hiep; Philips, Wilfried

2017-09-01

In this work we present Liborg, a spatial mapping and localization system that is able to acquire 3D models on the y using data originated from lidar sensors. The novelty of this work is in the highly efficient way we deal with the tremendous amount of data to guarantee fast execution times while preserving sufficiently high accuracy. The proposed solution is based on a multi-resolution technique based on octrees. The paper discusses and evaluates the main benefits of our approach including its efficiency regarding building and updating the map and its compactness regarding compressing the map. In addition, the paper presents a working prototype consisting of a robot equipped with a Velodyne Lidar Puck (VLP-16) and controlled by a Raspberry Pi serving as an independent acquisition platform.

Dynamically Reconfigurable Systolic Array Accelerator

NASA Technical Reports Server (NTRS)

Dasu, Aravind; Barnes, Robert

2012-01-01

A polymorphic systolic array framework has been developed that works in conjunction with an embedded microprocessor on a field-programmable gate array (FPGA), which allows for dynamic and complimentary scaling of acceleration levels of two algorithms active concurrently on the FPGA. Use is made of systolic arrays and a hardware-software co-design to obtain an efficient multi-application acceleration system. The flexible and simple framework allows hosting of a broader range of algorithms, and is extendable to more complex applications in the area of aerospace embedded systems. FPGA chips can be responsive to realtime demands for changing applications needs, but only if the electronic fabric can respond fast enough. This systolic array framework allows for rapid partial and dynamic reconfiguration of the chip in response to the real-time needs of scalability, and adaptability of executables.

A GPU-Based Architecture for Real-Time Data Assessment at Synchrotron Experiments

NASA Astrophysics Data System (ADS)

Chilingaryan, Suren; Mirone, Alessandro; Hammersley, Andrew; Ferrero, Claudio; Helfen, Lukas; Kopmann, Andreas; Rolo, Tomy dos Santos; Vagovic, Patrik

2011-08-01

Advances in digital detector technology leads presently to rapidly increasing data rates in imaging experiments. Using fast two-dimensional detectors in computed tomography, the data acquisition can be much faster than the reconstruction if no adequate measures are taken, especially when a high photon flux at synchrotron sources is used. We have optimized the reconstruction software employed at the micro-tomography beamlines of our synchrotron facilities to use the computational power of modern graphic cards. The main paradigm of our approach is the full utilization of all system resources. We use a pipelined architecture, where the GPUs are used as compute coprocessors to reconstruct slices, while the CPUs are preparing the next ones. Special attention is devoted to minimize data transfers between the host and GPU memory and to execute memory transfers in parallel with the computations. We were able to reduce the reconstruction time by a factor 30 and process a typical data set of 20 GB in 40 seconds. The time needed for the first evaluation of the reconstructed sample is reduced significantly and quasi real-time visualization is now possible.

Fast DRR generation for 2D to 3D registration on GPUs.

PubMed

Tornai, Gábor János; Cserey, György; Pappas, Ion

2012-08-01

The generation of digitally reconstructed radiographs (DRRs) is the most time consuming step on the CPU in intensity based two-dimensional x-ray to three-dimensional (CT or 3D rotational x-ray) medical image registration, which has application in several image guided interventions. This work presents optimized DRR rendering on graphical processor units (GPUs) and compares performance achievable on four commercially available devices. A ray-cast based DRR rendering was implemented for a 512 × 512 × 72 CT volume. The block size parameter was optimized for four different GPUs for a region of interest (ROI) of 400 × 225 pixels with different sampling ratios (1.1%-9.1% and 100%). Performance was statistically evaluated and compared for the four GPUs. The method and the block size dependence were validated on the latest GPU for several parameter settings with a public gold standard dataset (512 × 512 × 825 CT) for registration purposes. Depending on the GPU, the full ROI is rendered in 2.7-5.2 ms. If sampling ratio of 1.1%-9.1% is applied, execution time is in the range of 0.3-7.3 ms. On all GPUs, the mean of the execution time increased linearly with respect to the number of pixels if sampling was used. The presented results outperform other results from the literature. This indicates that automatic 2D to 3D registration, which typically requires a couple of hundred DRR renderings to converge, can be performed quasi on-line, in less than a second or depending on the application and hardware in less than a couple of seconds. Accordingly, a whole new field of applications is opened for image guided interventions, where the registration is continuously performed to match the real-time x-ray.

Accelerated Monte Carlo Simulation on the Chemical Stage in Water Radiolysis using GPU

PubMed Central

Tian, Zhen; Jiang, Steve B.; Jia, Xun

2018-01-01

The accurate simulation of water radiolysis is an important step to understand the mechanisms of radiobiology and quantitatively test some hypotheses regarding radiobiological effects. However, the simulation of water radiolysis is highly time consuming, taking hours or even days to be completed by a conventional CPU processor. This time limitation hinders cell-level simulations for a number of research studies. We recently initiated efforts to develop gMicroMC, a GPU-based fast microscopic MC simulation package for water radiolysis. The first step of this project focused on accelerating the simulation of the chemical stage, the most time consuming stage in the entire water radiolysis process. A GPU-friendly parallelization strategy was designed to address the highly correlated many-body simulation problem caused by the mutual competitive chemical reactions between the radiolytic molecules. Two cases were tested, using a 750 keV electron and a 5 MeV proton incident in pure water, respectively. The time-dependent yields of all the radiolytic species during the chemical stage were used to evaluate the accuracy of the simulation. The relative differences between our simulation and the Geant4-DNA simulation were on average 5.3% and 4.4% for the two cases. Our package, executed on an Nvidia Titan black GPU card, successfully completed the chemical stage simulation of the two cases within 599.2 s and 489.0 s. As compared with Geant4-DNA that was executed on an Intel i7-5500U CPU processor and needed 28.6 h and 26.8 h for the two cases using a single CPU core, our package achieved a speed-up factor of 171.1-197.2. PMID:28323637

Accelerated Monte Carlo simulation on the chemical stage in water radiolysis using GPU

NASA Astrophysics Data System (ADS)

Tian, Zhen; Jiang, Steve B.; Jia, Xun

2017-04-01

The accurate simulation of water radiolysis is an important step to understand the mechanisms of radiobiology and quantitatively test some hypotheses regarding radiobiological effects. However, the simulation of water radiolysis is highly time consuming, taking hours or even days to be completed by a conventional CPU processor. This time limitation hinders cell-level simulations for a number of research studies. We recently initiated efforts to develop gMicroMC, a GPU-based fast microscopic MC simulation package for water radiolysis. The first step of this project focused on accelerating the simulation of the chemical stage, the most time consuming stage in the entire water radiolysis process. A GPU-friendly parallelization strategy was designed to address the highly correlated many-body simulation problem caused by the mutual competitive chemical reactions between the radiolytic molecules. Two cases were tested, using a 750 keV electron and a 5 MeV proton incident in pure water, respectively. The time-dependent yields of all the radiolytic species during the chemical stage were used to evaluate the accuracy of the simulation. The relative differences between our simulation and the Geant4-DNA simulation were on average 5.3% and 4.4% for the two cases. Our package, executed on an Nvidia Titan black GPU card, successfully completed the chemical stage simulation of the two cases within 599.2 s and 489.0 s. As compared with Geant4-DNA that was executed on an Intel i7-5500U CPU processor and needed 28.6 h and 26.8 h for the two cases using a single CPU core, our package achieved a speed-up factor of 171.1-197.2.

Accelerated Monte Carlo simulation on the chemical stage in water radiolysis using GPU.

PubMed

Tian, Zhen; Jiang, Steve B; Jia, Xun

2017-04-21

The accurate simulation of water radiolysis is an important step to understand the mechanisms of radiobiology and quantitatively test some hypotheses regarding radiobiological effects. However, the simulation of water radiolysis is highly time consuming, taking hours or even days to be completed by a conventional CPU processor. This time limitation hinders cell-level simulations for a number of research studies. We recently initiated efforts to develop gMicroMC, a GPU-based fast microscopic MC simulation package for water radiolysis. The first step of this project focused on accelerating the simulation of the chemical stage, the most time consuming stage in the entire water radiolysis process. A GPU-friendly parallelization strategy was designed to address the highly correlated many-body simulation problem caused by the mutual competitive chemical reactions between the radiolytic molecules. Two cases were tested, using a 750 keV electron and a 5 MeV proton incident in pure water, respectively. The time-dependent yields of all the radiolytic species during the chemical stage were used to evaluate the accuracy of the simulation. The relative differences between our simulation and the Geant4-DNA simulation were on average 5.3% and 4.4% for the two cases. Our package, executed on an Nvidia Titan black GPU card, successfully completed the chemical stage simulation of the two cases within 599.2 s and 489.0 s. As compared with Geant4-DNA that was executed on an Intel i7-5500U CPU processor and needed 28.6 h and 26.8 h for the two cases using a single CPU core, our package achieved a speed-up factor of 171.1-197.2.

Scalable asynchronous execution of cellular automata

NASA Astrophysics Data System (ADS)

Folino, Gianluigi; Giordano, Andrea; Mastroianni, Carlo

2016-10-01

The performance and scalability of cellular automata, when executed on parallel/distributed machines, are limited by the necessity of synchronizing all the nodes at each time step, i.e., a node can execute only after the execution of the previous step at all the other nodes. However, these synchronization requirements can be relaxed: a node can execute one step after synchronizing only with the adjacent nodes. In this fashion, different nodes can execute different time steps. This can be a notable advantageous in many novel and increasingly popular applications of cellular automata, such as smart city applications, simulation of natural phenomena, etc., in which the execution times can be different and variable, due to the heterogeneity of machines and/or data and/or executed functions. Indeed, a longer execution time at a node does not slow down the execution at all the other nodes but only at the neighboring nodes. This is particularly advantageous when the nodes that act as bottlenecks vary during the application execution. The goal of the paper is to analyze the benefits that can be achieved with the described asynchronous implementation of cellular automata, when compared to the classical all-to-all synchronization pattern. The performance and scalability have been evaluated through a Petri net model, as this model is very useful to represent the synchronization barrier among nodes. We examined the usual case in which the territory is partitioned into a number of regions, and the computation associated with a region is assigned to a computing node. We considered both the cases of mono-dimensional and two-dimensional partitioning. The results show that the advantage obtained through the asynchronous execution, when compared to the all-to-all synchronous approach is notable, and it can be as large as 90% in terms of speedup.

Very fast motion planning for highly dexterous-articulated robots

NASA Technical Reports Server (NTRS)

Challou, Daniel J.; Gini, Maria; Kumar, Vipin

1994-01-01

Due to the inherent danger of space exploration, the need for greater use of teleoperated and autonomous robotic systems in space-based applications has long been apparent. Autonomous and semi-autonomous robotic devices have been proposed for carrying out routine functions associated with scientific experiments aboard the shuttle and space station. Finally, research into the use of such devices for planetary exploration continues. To accomplish their assigned tasks, all such autonomous and semi-autonomous devices will require the ability to move themselves through space without hitting themselves or the objects which surround them. In space it is important to execute the necessary motions correctly when they are first attempted because repositioning is expensive in terms of both time and resources (e.g., fuel). Finally, such devices will have to function in a variety of different environments. Given these constraints, a means for fast motion planning to insure the correct movement of robotic devices would be ideal. Unfortunately, motion planning algorithms are rarely used in practice because of their computational complexity. Fast methods have been developed for detecting imminent collisions, but the more general problem of motion planning remains computationally intractable. However, in this paper we show how the use of multicomputers and appropriate parallel algorithms can substantially reduce the time required to synthesize paths for dexterous articulated robots with a large number of joints. We have developed a parallel formulation of the Randomized Path Planner proposed by Barraquand and Latombe. We have shown that our parallel formulation is capable of formulating plans in a few seconds or less on various parallel architectures including: the nCUBE2 multicomputer with up to 1024 processors (nCUBE2 is a registered trademark of the nCUBE corporation), and a network of workstations.

Ghrelin is a possible new predictor associated with executive function in patients with type 2 diabetes mellitus.

PubMed

Chen, Siting; Zuo, Xuyang; Li, Yuan; Jiang, Tian; Zhang, Nan; Dai, Fang; Chen, Qiaoer; Zhang, Qiu

2017-05-01

The aim of the present research was to study the ghrelin level, executive function and their possible association in patients with type 2 diabetes mellitus. A total of 370 people were recruited between March 2015 and March 2016 in this study. Among them, 212 participants were patients with type 2 diabetes mellitus and 158 participants were included as the control group. Their blood sample was analyzed for the level of ghrelin and other clinical indexes. Cognitive function was measured by the Montreal Cognitive Assessment, and executive function was evaluated by the Wisconsin Card Sorting Test. In the type 2 diabetes mellitus group, age, years of education, duration of diabetes, fasting blood glucose, glycated hemoglobin, hypertension and waist-to-hip ratio were correlated with total Montreal Cognitive Assessment scores. No association was found between ghrelin level and total Montreal Cognitive Assessment score in patients with type 2 diabetes mellitus. However, ghrelin was found to be a significant predictor for executive function impairment measured by the Wisconsin Card Sorting Test in patients with type 2 diabetes mellitus. The level of serum ghrelin might be a biomarker of executive function and become a strong predictor of executive function impairment in patients with type 2 diabetes mellitus. Ghrelin might have a potential protective effect against cognitive function impairment in type 2 diabetes patients. © 2016 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

Decision making in high-velocity environments: implications for healthcare.

PubMed

Stepanovich, P L; Uhrig, J D

1999-01-01

Healthcare can be considered a high-velocity environment and, as such, can benefit from research conducted in other industries regarding strategic decision making. Strategic planning is not only relevant to firms in high-velocity environments, but is also important for high performance and survival. Specifically, decision-making speed seems to be instrumental in differentiating between high and low performers; fast decision makers outperform slow decision makers. This article outlines the differences between fast and slow decision makers, identifies five paralyses that can slow decision making in healthcare, and outlines the role of a planning department in circumventing these paralyses. Executives can use the proposed planning structure to improve both the speed and quality of strategic decisions. The structure uses planning facilitators to avoid the following five paralyses: 1. Analysis. Decision makers can no longer afford the luxury of lengthy, detailed analysis but must develop real-time systems that provide appropriate, timely information. 2. Alternatives. Many alternatives (beyond the traditional two or three) need to be considered and the alternatives must be evaluated simultaneously. 3. Group Think. Decision makers must avoid limited mind-sets and autocratic leadership styles by seeking out independent, knowledgeable counselors. 4. Process. Decision makers need to resolve conflicts through "consensus with qualification," as opposed to waiting for everyone to come on board. 5. Separation. Successful implementation requires a structured process that cuts across disciplines and levels.

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

Associations between daily physical activity and executive functioning in primary school-aged children.

PubMed

van der Niet, Anneke G; Smith, Joanne; Scherder, Erik J A; Oosterlaan, Jaap; Hartman, Esther; Visscher, Chris

2015-11-01

While there is some evidence that aerobic fitness is positively associated with executive functioning in children, evidence for a relation between children's daily physical activity and their executive functioning is limited. The objective was to examine associations between objectively measured daily physical activity (total volume, sedentary behavior, moderate to vigorous physical activity) and executive functioning in children. Cross-sectional. Eighty primary school children (36 boys, 44 girls) aged 8-12 years old participated in the study. Physical activity was measured using accelerometers. Executive functions measured included inhibition (Stroop test), working memory (Visual Memory Span test), cognitive flexibility (Trailmaking test), and planning (Tower of London). Total volume of physical activity, time spent in sedentary behavior and moderate to vigorous physical activity were calculated and related to performance on executive functioning. More time spent in sedentary behavior was related to worse inhibition (r = -0.24). A higher total volume of physical activity was associated with better planning ability, as reflected by both a higher score on the Tower of London (r = 0.24) and a shorter total execution time (r = -0.29). Also, a significant moderate correlation was found between time spent in moderate to vigorous physical activity and the total execution time of the Tower of London (r = -0.29). Children should limit time spent in sedentary behavior, and increasing their total physical activity. Total volume of physical activity, which consisted mostly of light intensity physical activity, is related to executive functioning. This opens up new possibilities to explore both the quantity and quality of physical activity in relation to cognition in children. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Less-structured time in children's daily lives predicts self-directed executive functioning.

PubMed

Barker, Jane E; Semenov, Andrei D; Michaelson, Laura; Provan, Lindsay S; Snyder, Hannah R; Munakata, Yuko

2014-01-01

Executive functions (EFs) in childhood predict important life outcomes. Thus, there is great interest in attempts to improve EFs early in life. Many interventions are led by trained adults, including structured training activities in the lab, and less-structured activities implemented in schools. Such programs have yielded gains in children's externally-driven executive functioning, where they are instructed on what goal-directed actions to carry out and when. However, it is less clear how children's experiences relate to their development of self-directed executive functioning, where they must determine on their own what goal-directed actions to carry out and when. We hypothesized that time spent in less-structured activities would give children opportunities to practice self-directed executive functioning, and lead to benefits. To investigate this possibility, we collected information from parents about their 6-7 year-old children's daily, annual, and typical schedules. We categorized children's activities as "structured" or "less-structured" based on categorization schemes from prior studies on child leisure time use. We assessed children's self-directed executive functioning using a well-established verbal fluency task, in which children generate members of a category and can decide on their own when to switch from one subcategory to another. The more time that children spent in less-structured activities, the better their self-directed executive functioning. The opposite was true of structured activities, which predicted poorer self-directed executive functioning. These relationships were robust (holding across increasingly strict classifications of structured and less-structured time) and specific (time use did not predict externally-driven executive functioning). We discuss implications, caveats, and ways in which potential interpretations can be distinguished in future work, to advance an understanding of this fundamental aspect of growing up.

Less-structured time in children's daily lives predicts self-directed executive functioning

PubMed Central

Barker, Jane E.; Semenov, Andrei D.; Michaelson, Laura; Provan, Lindsay S.; Snyder, Hannah R.; Munakata, Yuko

2014-01-01

Executive functions (EFs) in childhood predict important life outcomes. Thus, there is great interest in attempts to improve EFs early in life. Many interventions are led by trained adults, including structured training activities in the lab, and less-structured activities implemented in schools. Such programs have yielded gains in children's externally-driven executive functioning, where they are instructed on what goal-directed actions to carry out and when. However, it is less clear how children's experiences relate to their development of self-directed executive functioning, where they must determine on their own what goal-directed actions to carry out and when. We hypothesized that time spent in less-structured activities would give children opportunities to practice self-directed executive functioning, and lead to benefits. To investigate this possibility, we collected information from parents about their 6–7 year-old children's daily, annual, and typical schedules. We categorized children's activities as “structured” or “less-structured” based on categorization schemes from prior studies on child leisure time use. We assessed children's self-directed executive functioning using a well-established verbal fluency task, in which children generate members of a category and can decide on their own when to switch from one subcategory to another. The more time that children spent in less-structured activities, the better their self-directed executive functioning. The opposite was true of structured activities, which predicted poorer self-directed executive functioning. These relationships were robust (holding across increasingly strict classifications of structured and less-structured time) and specific (time use did not predict externally-driven executive functioning). We discuss implications, caveats, and ways in which potential interpretations can be distinguished in future work, to advance an understanding of this fundamental aspect of growing up. PMID:25071617

The mindful nurse leader: Key take-away: Go slow before you go fast.

PubMed

Doucette, Jeffrey N; Cotton, Amy; Arnow, Debra; Pipe, Teri; FitzPatrick, Kate

2016-11-01

The first and second articles in this three-part series on mindfulness described the production of the video "In the Moment: Stories of Mindfulness in Nursing" as part of the authors' Robert Wood Johnson Foundation Executive Nurse Fellowship program. In this final installment, we discuss our leadership approaches and lessons learned, both as a team and individuals.

Pharmacological Fingerprints of Contextual Uncertainty

PubMed Central

Ruge, Diane; Stephan, Klaas E.

2016-01-01

Successful interaction with the environment requires flexible updating of our beliefs about the world. By estimating the likelihood of future events, it is possible to prepare appropriate actions in advance and execute fast, accurate motor responses. According to theoretical proposals, agents track the variability arising from changing environments by computing various forms of uncertainty. Several neuromodulators have been linked to uncertainty signalling, but comprehensive empirical characterisation of their relative contributions to perceptual belief updating, and to the selection of motor responses, is lacking. Here we assess the roles of noradrenaline, acetylcholine, and dopamine within a single, unified computational framework of uncertainty. Using pharmacological interventions in a sample of 128 healthy human volunteers and a hierarchical Bayesian learning model, we characterise the influences of noradrenergic, cholinergic, and dopaminergic receptor antagonism on individual computations of uncertainty during a probabilistic serial reaction time task. We propose that noradrenaline influences learning of uncertain events arising from unexpected changes in the environment. In contrast, acetylcholine balances attribution of uncertainty to chance fluctuations within an environmental context, defined by a stable set of probabilistic associations, or to gross environmental violations following a contextual switch. Dopamine supports the use of uncertainty representations to engender fast, adaptive responses. PMID:27846219

A Fast Proceduere for Optimizing Thermal Protection Systems of Re-Entry Vehicles

NASA Astrophysics Data System (ADS)

Ferraiuolo, M.; Riccio, A.; Tescione, D.; Gigliotti, M.

The aim of the present work is to introduce a fast procedure to optimize thermal protection systems for re-entry vehicles subjected to high thermal loads. A simplified one-dimensional optimization process, performed in order to find the optimum design variables (lengths, sections etc.), is the first step of the proposed design procedure. Simultaneously, the most suitable materials able to sustain high temperatures and meeting the weight requirements are selected and positioned within the design layout. In this stage of the design procedure, simplified (generalized plane strain) FEM models are used when boundary and geometrical conditions allow the reduction of the degrees of freedom. Those simplified local FEM models can be useful because they are time-saving and very simple to build; they are essentially one dimensional and can be used for optimization processes in order to determine the optimum configuration with regard to weight, temperature and stresses. A triple-layer and a double-layer body, subjected to the same aero-thermal loads, have been optimized to minimize the overall weight. Full two and three-dimensional analyses are performed in order to validate those simplified models. Thermal-structural analyses and optimizations are executed by adopting the Ansys FEM code.

HMM based automated wheelchair navigation using EOG traces in EEG

NASA Astrophysics Data System (ADS)

Aziz, Fayeem; Arof, Hamzah; Mokhtar, Norrima; Mubin, Marizan

2014-10-01

This paper presents a wheelchair navigation system based on a hidden Markov model (HMM), which we developed to assist those with restricted mobility. The semi-autonomous system is equipped with obstacle/collision avoidance sensors and it takes the electrooculography (EOG) signal traces from the user as commands to maneuver the wheelchair. The EOG traces originate from eyeball and eyelid movements and they are embedded in EEG signals collected from the scalp of the user at three different locations. Features extracted from the EOG traces are used to determine whether the eyes are open or closed, and whether the eyes are gazing to the right, center, or left. These features are utilized as inputs to a few support vector machine (SVM) classifiers, whose outputs are regarded as observations to an HMM. The HMM determines the state of the system and generates commands for navigating the wheelchair accordingly. The use of simple features and the implementation of a sliding window that captures important signatures in the EOG traces result in a fast execution time and high classification rates. The wheelchair is equipped with a proximity sensor and it can move forward and backward in three directions. The asynchronous system achieved an average classification rate of 98% when tested with online data while its average execution time was less than 1 s. It was also tested in a navigation experiment where all of the participants managed to complete the tasks successfully without collisions.

HMM based automated wheelchair navigation using EOG traces in EEG.

PubMed

Aziz, Fayeem; Arof, Hamzah; Mokhtar, Norrima; Mubin, Marizan

2014-10-01

This paper presents a wheelchair navigation system based on a hidden Markov model (HMM), which we developed to assist those with restricted mobility. The semi-autonomous system is equipped with obstacle/collision avoidance sensors and it takes the electrooculography (EOG) signal traces from the user as commands to maneuver the wheelchair. The EOG traces originate from eyeball and eyelid movements and they are embedded in EEG signals collected from the scalp of the user at three different locations. Features extracted from the EOG traces are used to determine whether the eyes are open or closed, and whether the eyes are gazing to the right, center, or left. These features are utilized as inputs to a few support vector machine (SVM) classifiers, whose outputs are regarded as observations to an HMM. The HMM determines the state of the system and generates commands for navigating the wheelchair accordingly. The use of simple features and the implementation of a sliding window that captures important signatures in the EOG traces result in a fast execution time and high classification rates. The wheelchair is equipped with a proximity sensor and it can move forward and backward in three directions. The asynchronous system achieved an average classification rate of 98% when tested with online data while its average execution time was less than 1 s. It was also tested in a navigation experiment where all of the participants managed to complete the tasks successfully without collisions.

Clues for minimal hepatic encephalopathy in children with noncirrhotic portal hypertension.

PubMed

D'Antiga, Lorenzo; Dacchille, Patrizia; Boniver, Clementina; Poledri, Sara; Schiff, Sami; Zancan, Lucia; Amodio, Piero

2014-12-01

In children with noncirrhotic extrahepatic portal vein obstruction (EHPVO), minimal hepatic encephalopathy (MHE) was reported in a few series, but neither is it routinely investigated nor does consensus about its diagnosis exist. In this prospective observational study we aimed at detecting the prevalence of MHE in children with EHPVO and providing a practical diagnostic protocol. A consecutive sample of 13 noncirrhotic children (age range 4-18 years) with EHPVO underwent a screening for MHE based on level of fasting ammonia, quantified electroencephalogram (EEG) evaluation, and a wide battery of 26 psychometric tests exploring learning ability, abstract reasoning, phonemic and semantic fluency, selective attention, executive functions, short-term verbal and visual memory, long-term verbal memory, and visuopractic ability. Five children had at least 2 altered psychometric tests. Selective attention, executive function, and short-term visual memory were the domains more frequently altered, and 4 tests were enough to detect 80% of these children. Fasting ammonia plasma level was increased in 6 children. EEG mean dominant frequency adjusted for age was associated with serum ammonia concentration (β = -0.44 ± 0.19, P < 0.05). As a whole, children with EHPVO showed trends for lower α (median 41% vs 49%) and higher θ power than controls (median 41% vs 49% and 29% vs 20%, respectively). MHE affects approximately 50% of children with EHPVO and, therefore, is worthwhile to be investigated. Three simple tools, serum ammonia, quantified EEG, and neuropsychological examination, focused on selective attention, executive function, and short-term visual memory can be used effectively in the evaluation of MHE in this setting.

Executive functioning complaints and escitalopram treatment response in late-life depression.

PubMed

Manning, Kevin J; Alexopoulos, George S; Banerjee, Samprit; Morimoto, Sarah Shizuko; Seirup, Joanna K; Klimstra, Sibel A; Yuen, Genevieve; Kanellopoulos, Theodora; Gunning-Dixon, Faith

2015-05-01

Executive dysfunction may play a key role in the pathophysiology of late-life depression. Executive dysfunction can be assessed with cognitive tests and subjective report of difficulties with executive skills. The present study investigated the association between subjective report of executive functioning complaints and time to escitalopram treatment response in older adults with major depressive disorder (MDD). 100 older adults with MDD (58 with executive functioning complaints and 42 without executive functioning complaints) completed a 12-week trial of escitalopram. Treatment response over 12 weeks, as measured by repeated Hamilton Depression Rating Scale scores, was compared for adults with and without executive complaints using mixed-effects modeling. Mixed effects analysis revealed a significant group × time interaction, F(1, 523.34) = 6.00, p = 0.01. Depressed older adults who reported executive functioning complaints at baseline demonstrated a slower response to escitalopram treatment than those without executive functioning complaints. Self-report of executive functioning difficulties may be a useful prognostic indicator for subsequent speed of response to antidepressant medication. Copyright © 2015 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

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.

TH-A-18C-09: Ultra-Fast Monte Carlo Simulation for Cone Beam CT Imaging of Brain Trauma

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

Sisniega, A; Zbijewski, W; Stayman, J

Purpose: Application of cone-beam CT (CBCT) to low-contrast soft tissue imaging, such as in detection of traumatic brain injury, is challenged by high levels of scatter. A fast, accurate scatter correction method based on Monte Carlo (MC) estimation is developed for application in high-quality CBCT imaging of acute brain injury. Methods: The correction involves MC scatter estimation executed on an NVIDIA GTX 780 GPU (MC-GPU), with baseline simulation speed of ~1e7 photons/sec. MC-GPU is accelerated by a novel, GPU-optimized implementation of variance reduction (VR) techniques (forced detection and photon splitting). The number of simulated tracks and projections is reduced formore » additional speed-up. Residual noise is removed and the missing scatter projections are estimated via kernel smoothing (KS) in projection plane and across gantry angles. The method is assessed using CBCT images of a head phantom presenting a realistic simulation of fresh intracranial hemorrhage (100 kVp, 180 mAs, 720 projections, source-detector distance 700 mm, source-axis distance 480 mm). Results: For a fixed run-time of ~1 sec/projection, GPU-optimized VR reduces the noise in MC-GPU scatter estimates by a factor of 4. For scatter correction, MC-GPU with VR is executed with 4-fold angular downsampling and 1e5 photons/projection, yielding 3.5 minute run-time per scan, and de-noised with optimized KS. Corrected CBCT images demonstrate uniformity improvement of 18 HU and contrast improvement of 26 HU compared to no correction, and a 52% increase in contrast-tonoise ratio in simulated hemorrhage compared to “oracle” constant fraction correction. Conclusion: Acceleration of MC-GPU achieved through GPU-optimized variance reduction and kernel smoothing yields an efficient (<5 min/scan) and accurate scatter correction that does not rely on additional hardware or simplifying assumptions about the scatter distribution. The method is undergoing implementation in a novel CBCT dedicated to brain trauma imaging at the point of care in sports and military applications. Research grant from Carestream Health. JY is an employee of Carestream Health.« less

Resource conflict detection and removal strategy for nondeterministic emergency response processes using Petri nets

NASA Astrophysics Data System (ADS)

Zeng, Qingtian; Liu, Cong; Duan, Hua

2016-09-01

Correctness of an emergency response process specification is critical to emergency mission success. Therefore, errors in the specification should be detected and corrected at build-time. In this paper, we propose a resource conflict detection approach and removal strategy for emergency response processes constrained by resources and time. In this kind of emergency response process, there are two timing functions representing the minimum and maximum execution time for each activity, respectively, and many activities require resources to be executed. Based on the RT_ERP_Net, the earliest time to start each activity and the ideal execution time of the process can be obtained. To detect and remove the resource conflicts in the process, the conflict detection algorithms and a priority-activity-first resolution strategy are given. In this way, real execution time for each activity is obtained and a conflict-free RT_ERP_Net is constructed by adding virtual activities. By experiments, it is proved that the resolution strategy proposed can shorten the execution time of the whole process to a great degree.

Estimation Accuracy on Execution Time of Run-Time Tasks in a Heterogeneous Distributed Environment.

PubMed

Liu, Qi; Cai, Weidong; Jin, Dandan; Shen, Jian; Fu, Zhangjie; Liu, Xiaodong; Linge, Nigel

2016-08-30

Distributed Computing has achieved tremendous development since cloud computing was proposed in 2006, and played a vital role promoting rapid growth of data collecting and analysis models, e.g., Internet of things, Cyber-Physical Systems, Big Data Analytics, etc. Hadoop has become a data convergence platform for sensor networks. As one of the core components, MapReduce facilitates allocating, processing and mining of collected large-scale data, where speculative execution strategies help solve straggler problems. However, there is still no efficient solution for accurate estimation on execution time of run-time tasks, which can affect task allocation and distribution in MapReduce. In this paper, task execution data have been collected and employed for the estimation. A two-phase regression (TPR) method is proposed to predict the finishing time of each task accurately. Detailed data of each task have drawn interests with detailed analysis report being made. According to the results, the prediction accuracy of concurrent tasks' execution time can be improved, in particular for some regular jobs.

System matrix computation vs storage on GPU: A comparative study in cone beam CT.

PubMed

Matenine, Dmitri; Côté, Geoffroi; Mascolo-Fortin, Julia; Goussard, Yves; Després, Philippe

2018-02-01

Iterative reconstruction algorithms in computed tomography (CT) require a fast method for computing the intersection distances between the trajectories of photons and the object, also called ray tracing or system matrix computation. This work focused on the thin-ray model is aimed at comparing different system matrix handling strategies using graphical processing units (GPUs). In this work, the system matrix is modeled by thin rays intersecting a regular grid of box-shaped voxels, known to be an accurate representation of the forward projection operator in CT. However, an uncompressed system matrix exceeds the random access memory (RAM) capacities of typical computers by one order of magnitude or more. Considering the RAM limitations of GPU hardware, several system matrix handling methods were compared: full storage of a compressed system matrix, on-the-fly computation of its coefficients, and partial storage of the system matrix with partial on-the-fly computation. These methods were tested on geometries mimicking a cone beam CT (CBCT) acquisition of a human head. Execution times of three routines of interest were compared: forward projection, backprojection, and ordered-subsets convex (OSC) iteration. A fully stored system matrix yielded the shortest backprojection and OSC iteration times, with a 1.52× acceleration for OSC when compared to the on-the-fly approach. Nevertheless, the maximum problem size was bound by the available GPU RAM and geometrical symmetries. On-the-fly coefficient computation did not require symmetries and was shown to be the fastest for forward projection. It also offered reasonable execution times of about 176.4 ms per view per OSC iteration for a detector of 512 × 448 pixels and a volume of 384 3 voxels, using commodity GPU hardware. Partial system matrix storage has shown a performance similar to the on-the-fly approach, while still relying on symmetries. Partial system matrix storage was shown to yield the lowest relative performance. On-the-fly ray tracing was shown to be the most flexible method, yielding reasonable execution times. A fully stored system matrix allowed for the lowest backprojection and OSC iteration times and may be of interest for certain performance-oriented applications. © 2017 American Association of Physicists in Medicine.

Mobile Cloud Computing with SOAP and REST Web Services

NASA Astrophysics Data System (ADS)

Ali, Mushtaq; Fadli Zolkipli, Mohamad; Mohamad Zain, Jasni; Anwar, Shahid

2018-05-01

Mobile computing in conjunction with Mobile web services drives a strong approach where the limitations of mobile devices may possibly be tackled. Mobile Web Services are based on two types of technologies; SOAP and REST, which works with the existing protocols to develop Web services. Both the approaches carry their own distinct features, yet to keep the constraint features of mobile devices in mind, the better in two is considered to be the one which minimize the computation and transmission overhead while offloading. The load transferring of mobile device to remote servers for execution called computational offloading. There are numerous approaches to implement computational offloading a viable solution for eradicating the resources constraints of mobile device, yet a dynamic method of computational offloading is always required for a smooth and simple migration of complex tasks. The intention of this work is to present a distinctive approach which may not engage the mobile resources for longer time. The concept of web services utilized in our work to delegate the computational intensive tasks for remote execution. We tested both SOAP Web services approach and REST Web Services for mobile computing. Two parameters considered in our lab experiments to test; Execution Time and Energy Consumption. The results show that RESTful Web services execution is far better than executing the same application by SOAP Web services approach, in terms of execution time and energy consumption. Conducting experiments with the developed prototype matrix multiplication app, REST execution time is about 200% better than SOAP execution approach. In case of energy consumption REST execution is about 250% better than SOAP execution approach.

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.

Rapid processing of PET list-mode data for efficient uncertainty estimation and data analysis

NASA Astrophysics Data System (ADS)

Markiewicz, P. J.; Thielemans, K.; Schott, J. M.; Atkinson, D.; Arridge, S. R.; Hutton, B. F.; Ourselin, S.

2016-07-01

In this technical note we propose a rapid and scalable software solution for the processing of PET list-mode data, which allows the efficient integration of list mode data processing into the workflow of image reconstruction and analysis. All processing is performed on the graphics processing unit (GPU), making use of streamed and concurrent kernel execution together with data transfers between disk and CPU memory as well as CPU and GPU memory. This approach leads to fast generation of multiple bootstrap realisations, and when combined with fast image reconstruction and analysis, it enables assessment of uncertainties of any image statistic and of any component of the image generation process (e.g. random correction, image processing) within reasonable time frames (e.g. within five minutes per realisation). This is of particular value when handling complex chains of image generation and processing. The software outputs the following: (1) estimate of expected random event data for noise reduction; (2) dynamic prompt and random sinograms of span-1 and span-11 and (3) variance estimates based on multiple bootstrap realisations of (1) and (2) assuming reasonable count levels for acceptable accuracy. In addition, the software produces statistics and visualisations for immediate quality control and crude motion detection, such as: (1) count rate curves; (2) centre of mass plots of the radiodistribution for motion detection; (3) video of dynamic projection views for fast visual list-mode skimming and inspection; (4) full normalisation factor sinograms. To demonstrate the software, we present an example of the above processing for fast uncertainty estimation of regional SUVR (standard uptake value ratio) calculation for a single PET scan of 18F-florbetapir using the Siemens Biograph mMR scanner.

A prospective investigation of rumination and executive control in predicting overgeneral autobiographical memory in adolescence.

PubMed

Stewart, Tracy M; Hunter, Simon C; Rhodes, Sinéad M

2018-04-01

The CaR-FA-X model (Williams et al., 2007), or capture and rumination (CaR), functional avoidance (FA), and impaired executive control (X), is a model of overgeneral autobiographical memory (OGM). Two mechanisms of the model, rumination and executive control, were examined in isolation and in interaction in order to investigate OGM over time. Across two time points, six months apart, a total of 149 adolescents (13-16 years) completed the minimal-instruction autobiographical memory test, a measure of executive control with both emotional and nonemotional stimuli, and measures of brooding rumination and reflective pondering. The results showed that executive control for emotional information was negatively associated with OGM, but only when reflective pondering levels were high. Therefore, in the context of higher levels of reflective pondering, greater switch costs (i.e., lower executive control) when processing emotional information predicted a decrease in OGM over time.

Motor Execution Affects Action Prediction

ERIC Educational Resources Information Center

Springer, Anne; Brandstadter, Simone; Liepelt, Roman; Birngruber, Teresa; Giese, Martin; Mechsner, Franz; Prinz, Wolfgang

2011-01-01

Previous studies provided evidence of the claim that the prediction of occluded action involves real-time simulation. We report two experiments that aimed to study how real-time simulation is affected by simultaneous action execution under conditions of full, partial or no overlap between observed and executed actions. This overlap was analysed by…

Participation of Part-time Faculty on the Executive Committee of the Academic Senate for California Community Colleges.

ERIC Educational Resources Information Center

Academic Senate for California Community Colleges, Sacramento.

At the 1996 Spring Plenary Session, the Academic Senate for California Community Colleges (ASCCC) passed resolution S961.5, which authorizes the participation of part-time faculty on the Executive Committee. The assurance of participation of part-time faculty on the Executive Committee of the ASCCC at first appeared a simple proposal, but was soon…

HEALPix: A Framework for High-Resolution Discretization and Fast Analysis of Data Distributed on the Sphere

NASA Technical Reports Server (NTRS)

Gorski, K. M.; Hivon, Eric; Banday, A. J.; Wandelt, Benjamin D.; Hansen, Frode K.; Reinecke, Mstvos; Bartelmann, Matthia

2005-01-01

HEALPix the Hierarchical Equal Area isoLatitude Pixelization is a versatile structure for the pixelization of data on the sphere. An associated library of computational algorithms and visualization software supports fast scientific applications executable directly on discretized spherical maps generated from very large volumes of astronomical data. Originally developed to address the data processing and analysis needs of the present generation of cosmic microwave background experiments (e.g., BOOMERANG, WMAP), HEALPix can be expanded to meet many of the profound challenges that will arise in confrontation with the observational output of future missions and experiments, including, e.g., Planck, Herschel, SAFIR, and the Beyond Einstein inflation probe. In this paper we consider the requirements and implementation constraints on a framework that simultaneously enables an efficient discretization with associated hierarchical indexation and fast analysis/synthesis of functions defined on the sphere. We demonstrate how these are explicitly satisfied by HEALPix.

Application-oriented offloading in heterogeneous networks for mobile cloud computing

NASA Astrophysics Data System (ADS)

Tseng, Fan-Hsun; Cho, Hsin-Hung; Chang, Kai-Di; Li, Jheng-Cong; Shih, Timothy K.

2018-04-01

Nowadays Internet applications have become more complicated that mobile device needs more computing resources for shorter execution time but it is restricted to limited battery capacity. Mobile cloud computing (MCC) is emerged to tackle the finite resource problem of mobile device. MCC offloads the tasks and jobs of mobile devices to cloud and fog environments by using offloading scheme. It is vital to MCC that which task should be offloaded and how to offload efficiently. In the paper, we formulate the offloading problem between mobile device and cloud data center and propose two algorithms based on application-oriented for minimum execution time, i.e. the Minimum Offloading Time for Mobile device (MOTM) algorithm and the Minimum Execution Time for Cloud data center (METC) algorithm. The MOTM algorithm minimizes offloading time by selecting appropriate offloading links based on application categories. The METC algorithm minimizes execution time in cloud data center by selecting virtual and physical machines with corresponding resource requirements of applications. Simulation results show that the proposed mechanism not only minimizes total execution time for mobile devices but also decreases their energy consumption.

The Effects of Breakfast and Breakfast Composition on Cognition in Adults123

PubMed Central

Spitznagel, Mary Beth

2016-01-01

Extensive literature has addressed the acute cognitive effects of breaking a fast. Recent reviews in this line of work have synthesized available research on the cognitive consequences of fasting compared with nutrient intake and the cognitive effects of macronutrient consumption. These largely have been inconclusive, possibly in part because of selection criteria limiting the scope of studies covered. The purpose of the current review is to integrate the results of the literature examining the cognitive effects of breakfast and breakfast composition in adults with the use of a flexible definition of breakfast, specifically, any caloric intake after a fasting period of ≥8 h. This review includes 38 studies that examine the acute cognitive impact of breakfast and 16 studies that examine the effects of breakfast composition. Results suggest that healthy adults show a small but robust advantage for memory (particularly delayed recall) from consuming breakfast. Largely equivocal results emerge for attention and motor and executive function; there were no effects from breakfast on language. Regarding breakfast composition, a smaller number of studies and widely disparate methodology addressing this question preclude definitive conclusions about the effects of cognition. A subset of this literature examines these questions in the context of glucoregulation; the findings emphasize the importance of considering differences in glucoregulation in research designs, even among healthy cohorts. The limitations of this literature include methodologic differences, such as the use of different tests to measure cognitive constructs, as well as the effects of timing in test administration. PMID:27184286

Makalu: fast recoverable allocation of non-volatile memory

DOE PAGES

Bhandari, Kumud; Chakrabarti, Dhruva R.; Boehm, Hans-J.

2016-10-19

Byte addressable non-volatile memory (NVRAM) is likely to supplement, and perhaps eventually replace, DRAM. Applications can then persist data structures directly in memory instead of serializing them and storing them onto a durable block device. However, failures during execution can leave data structures in NVRAM unreachable or corrupt. In this paper, we present Makalu, a system that addresses non-volatile memory management. Makalu offers an integrated allocator and recovery-time garbage collector that maintains internal consistency, avoids NVRAM memory leaks, and is efficient, all in the face of failures. We show that a careful allocator design can support a less restrictive andmore » a much more familiar programming model than existing persistent memory allocators. Our allocator significantly reduces the per allocation persistence overhead by lazily persisting non-essential metadata and by employing a post-failure recovery-time garbage collector. Experimental results show that the resulting online speed and scalability of our allocator are comparable to well-known transient allocators, and significantly better than state-of-the-art persistent allocators.« less

GPU-based streaming architectures for fast cone-beam CT image reconstruction and demons deformable registration.

PubMed

Sharp, G C; Kandasamy, N; Singh, H; Folkert, M

2007-10-07

This paper shows how to significantly accelerate cone-beam CT reconstruction and 3D deformable image registration using the stream-processing model. We describe data-parallel designs for the Feldkamp, Davis and Kress (FDK) reconstruction algorithm, and the demons deformable registration algorithm, suitable for use on a commodity graphics processing unit. The streaming versions of these algorithms are implemented using the Brook programming environment and executed on an NVidia 8800 GPU. Performance results using CT data of a preserved swine lung indicate that the GPU-based implementations of the FDK and demons algorithms achieve a substantial speedup--up to 80 times for FDK and 70 times for demons when compared to an optimized reference implementation on a 2.8 GHz Intel processor. In addition, the accuracy of the GPU-based implementations was found to be excellent. Compared with CPU-based implementations, the RMS differences were less than 0.1 Hounsfield unit for reconstruction and less than 0.1 mm for deformable registration.

Nobody Is Perfect: ERP Effects Prior to Performance Errors in Musicians Indicate Fast Monitoring Processes

PubMed Central

Maidhof, Clemens; Rieger, Martina; Prinz, Wolfgang; Koelsch, Stefan

2009-01-01

Background One central question in the context of motor control and action monitoring is at what point in time errors can be detected. Previous electrophysiological studies investigating this issue focused on brain potentials elicited after erroneous responses, mainly in simple speeded response tasks. In the present study, we investigated brain potentials before the commission of errors in a natural and complex situation. Methodology/Principal Findings Expert pianists bimanually played scales and patterns while the electroencephalogram (EEG) was recorded. Event-related potentials (ERPs) were computed for correct and incorrect performances. Results revealed differences already 100 ms prior to the onset of a note (i.e., prior to auditory feedback). We further observed that erroneous keystrokes were delayed in time and pressed more slowly. Conclusions Our data reveal neural mechanisms in musicians that are able to detect errors prior to the execution of erroneous movements. The underlying mechanism probably relies on predictive control processes that compare the predicted outcome of an action with the action goal. PMID:19337379

Makalu: fast recoverable allocation of non-volatile memory

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

Bhandari, Kumud; Chakrabarti, Dhruva R.; Boehm, Hans-J.

Byte addressable non-volatile memory (NVRAM) is likely to supplement, and perhaps eventually replace, DRAM. Applications can then persist data structures directly in memory instead of serializing them and storing them onto a durable block device. However, failures during execution can leave data structures in NVRAM unreachable or corrupt. In this paper, we present Makalu, a system that addresses non-volatile memory management. Makalu offers an integrated allocator and recovery-time garbage collector that maintains internal consistency, avoids NVRAM memory leaks, and is efficient, all in the face of failures. We show that a careful allocator design can support a less restrictive andmore » a much more familiar programming model than existing persistent memory allocators. Our allocator significantly reduces the per allocation persistence overhead by lazily persisting non-essential metadata and by employing a post-failure recovery-time garbage collector. Experimental results show that the resulting online speed and scalability of our allocator are comparable to well-known transient allocators, and significantly better than state-of-the-art persistent allocators.« less

Comparison of cognitive functions between male and female medical students: a pilot study.

PubMed

Upadhayay, Namrata; Guragain, Sanjeev

2014-06-01

There are gender differences in cognitive abilities. The major enigma is whether males or females perform better in various cognitive tasks. The reports were found to be contradictory. Studies have shown that oestrogen and testosterone accentuate cognitive functions. But the effects of progesterone on cognitive functions are still contradictory. To assess and compare the cognitive functions between male and female students. This study was conducted on healthy male (n=21) and female (n=21) volunteers who were aged between 19-37 years. Cognitive functions which were assessed in males (one time) and females (two times: during preovulatory and postovulatory phases of the menstrual cycle) were attentional: visual reaction time (VRT) and Go/No-Go VRT; perceptual: fast counting (FC), executive: Erisken Flanker Test (EFT) and Stroop Test (ST), and working memory. Data were compared by using Mann-Whitney U-test. Cognitive functions in female preovulatory phase were comparable to male cognitive functions. In addition, the female postovulatory phase cognitive functions were also similar to those of males in all the tasks, except those seen in VRT and ST. Male performed better than females in VRT (M: 331.66 ms, IQR: 286.99-375.33 vs. M: 367.8 ms, IQR: 340.66-435.66; p=0.05). However, in ST, females showed higher accuracies in reading colour interferences than males (M: 100%, IQR: 95.12-100 vs. M: 95.24%, IQR: 86.36-100; p=0.04). In addition, males showed trend of a poorer performance than females in Go/No-Go VRT, ST colour reading normal time and interference time and in working-memory time. Male cognitive functions were comparable to female preovulatory phase cognitive functions. However, females, during postovulatory phase of their cycle, may have advantages in executive tasks (Stroop test) and disadvantages in attentional tasks (VRT), as compared to males.

A bidirectional relationship between physical activity and executive function in older adults

PubMed Central

Daly, Michael; McMinn, David; Allan, Julia L.

2015-01-01

Physically active lifestyles contribute to better executive function. However, it is unclear whether high levels of executive function lead people to be more active. This study uses a large sample and multi-wave data to identify whether a reciprocal association exists between physical activity and executive function. Participants were 4555 older adults tracked across four waves of the English Longitudinal Study of Aging. In each wave executive function was assessed using a verbal fluency test and a letter cancelation task and participants reported their physical activity levels. Fixed effects regressions showed that changes in executive function corresponded with changes in physical activity. In longitudinal multilevel models low levels of physical activity led to subsequent declines in executive function. Importantly, poor executive function predicted reductions in physical activity over time. This association was found to be over 50% larger in magnitude than the contribution of physical activity to changes in executive function. This is the first study to identify evidence for a robust bidirectional link between executive function and physical activity in a large sample of older adults tracked over time. PMID:25628552

A dangerous seaplane landing condition

NASA Technical Reports Server (NTRS)

Carroll, Thomas

1928-01-01

A peculiar phenomena in seaplane landing is observed and reported. The seaplane having executed a normal fast landing at low incidence, a forward movement of the control stick effected an unusual condition in that the seaplane left the water suddenly in an abnormal attitude. The observations describing this phenomena are offered as a warning against possible accident and as a conjectural cause of seaplane landing accidents of a certain kind.

3D Hybrid Simulations of Interactions of High-Velocity Plasmoids with Obstacles

NASA Astrophysics Data System (ADS)

Omelchenko, Y. A.; Weber, T. E.; Smith, R. J.

2015-11-01

Interactions of fast plasma streams and objects with magnetic obstacles (dipoles, mirrors, etc) lie at the core of many space and laboratory plasma phenomena ranging from magnetoshells and solar wind interactions with planetary magnetospheres to compact fusion plasmas (spheromaks and FRCs) to astrophysics-in-lab experiments. Properly modeling ion kinetic, finite-Larmor radius and Hall effects is essential for describing large-scale plasma dynamics, turbulence and heating in complex magnetic field geometries. Using an asynchronous parallel hybrid code, HYPERS, we conduct 3D hybrid (particle-in-cell ion, fluid electron) simulations of such interactions under realistic conditions that include magnetic flux coils, ion-ion collisions and the Chodura resistivity. HYPERS does not step simulation variables synchronously in time but instead performs time integration by executing asynchronous discrete events: updates of particles and fields carried out as frequently as dictated by local physical time scales. Simulations are compared with data from the MSX experiment which studies the physics of magnetized collisionless shocks through the acceleration and subsequent stagnation of FRC plasmoids against a strong magnetic mirror and flux-conserving boundary.

The effect of state anxiety on the online and offline control of fast target-directed movements.

PubMed

Lawrence, Gavin P; Khan, Michael A; Hardy, Lew

2013-07-01

In target-directed aiming, afferent information is used to adjust limb trajectories during movement execution (i.e. online) and to enhance the programming of subsequent trials (i.e. offline). The objective of the present study was to determine the influence of state anxiety on both online and offline afferent information processing for the first time. Participants practiced either a directional aiming task (Experiment 1) or an amplitude aiming task (Experiment 2) without anxiety before being transferred to a high anxiety condition. In both experiments, results revealed that anxiety resulted in a decrement in performance. Furthermore, use of afferent information to adjust movement trajectories online was disrupted when movements were performed with anxiety, whereas there were no differences in the offline processing of afferent information between the low anxiety and high anxiety conditions.

Horizontal decomposition of data table for finding one reduct

NASA Astrophysics Data System (ADS)

Hońko, Piotr

2018-04-01

Attribute reduction, being one of the most essential tasks in rough set theory, is a challenge for data that does not fit in the available memory. This paper proposes new definitions of attribute reduction using horizontal data decomposition. Algorithms for computing superreduct and subsequently exact reducts of a data table are developed and experimentally verified. In the proposed approach, the size of subtables obtained during the decomposition can be arbitrarily small. Reducts of the subtables are computed independently from one another using any heuristic method for finding one reduct. Compared with standard attribute reduction methods, the proposed approach can produce superreducts that usually inconsiderably differ from an exact reduct. The approach needs comparable time and much less memory to reduce the attribute set. The method proposed for removing unnecessary attributes from superreducts executes relatively fast for bigger databases.

Job-mix modeling and system analysis of an aerospace multiprocessor.

NASA Technical Reports Server (NTRS)

Mallach, E. G.

1972-01-01

An aerospace guidance computer organization, consisting of multiple processors and memory units attached to a central time-multiplexed data bus, is described. A job mix for this type of computer is obtained by analysis of Apollo mission programs. Multiprocessor performance is then analyzed using: 1) queuing theory, under certain 'limiting case' assumptions; 2) Markov process methods; and 3) system simulation. Results of the analyses indicate: 1) Markov process analysis is a useful and efficient predictor of simulation results; 2) efficient job execution is not seriously impaired even when the system is so overloaded that new jobs are inordinately delayed in starting; 3) job scheduling is significant in determining system performance; and 4) a system having many slow processors may or may not perform better than a system of equal power having few fast processors, but will not perform significantly worse.

SubspaceEM: A Fast Maximum-a-posteriori Algorithm for Cryo-EM Single Particle Reconstruction

PubMed Central

Dvornek, Nicha C.; Sigworth, Fred J.; Tagare, Hemant D.

2015-01-01

Single particle reconstruction methods based on the maximum-likelihood principle and the expectation-maximization (E–M) algorithm are popular because of their ability to produce high resolution structures. However, these algorithms are computationally very expensive, requiring a network of computational servers. To overcome this computational bottleneck, we propose a new mathematical framework for accelerating maximum-likelihood reconstructions. The speedup is by orders of magnitude and the proposed algorithm produces similar quality reconstructions compared to the standard maximum-likelihood formulation. Our approach uses subspace approximations of the cryo-electron microscopy (cryo-EM) data and projection images, greatly reducing the number of image transformations and comparisons that are computed. Experiments using simulated and actual cryo-EM data show that speedup in overall execution time compared to traditional maximum-likelihood reconstruction reaches factors of over 300. PMID:25839831

Multithreaded implicitly dealiased convolutions

NASA Astrophysics Data System (ADS)

Roberts, Malcolm; Bowman, John C.

2018-03-01

Implicit dealiasing is a method for computing in-place linear convolutions via fast Fourier transforms that decouples work memory from input data. It offers easier memory management and, for long one-dimensional input sequences, greater efficiency than conventional zero-padding. Furthermore, for convolutions of multidimensional data, the segregation of data and work buffers can be exploited to reduce memory usage and execution time significantly. This is accomplished by processing and discarding data as it is generated, allowing work memory to be reused, for greater data locality and performance. A multithreaded implementation of implicit dealiasing that accepts an arbitrary number of input and output vectors and a general multiplication operator is presented, along with an improved one-dimensional Hermitian convolution that avoids the loop dependency inherent in previous work. An alternate data format that can accommodate a Nyquist mode and enhance cache efficiency is also proposed.

Cone beam computed tomography and intraoral radiography for diagnosis of dental abnormalities in dogs and cats

PubMed Central

Silva, Luiz Antonio F.; Barriviera, Mauricio; Januário, Alessandro L.; Bezerra, Ana Cristina B.; Fioravanti, Maria Clorinda S.

2011-01-01

The development of veterinary dentistry has substantially improved the ability to diagnose canine and feline dental abnormalities. Consequently, examinations previously performed only on humans are now available for small animals, thus improving the diagnostic quality. This has increased the need for technical qualification of veterinary professionals and increased technological investments. This study evaluated the use of cone beam computed tomography and intraoral radiography as complementary exams for diagnosing dental abnormalities in dogs and cats. Cone beam computed tomography was provided faster image acquisition with high image quality, was associated with low ionizing radiation levels, enabled image editing, and reduced the exam duration. Our results showed that radiography was an effective method for dental radiographic examination with low cost and fast execution times, and can be performed during surgical procedures. PMID:22122905

28 CFR 26.3 - Date, time, place, and method of execution.

Code of Federal Regulations, 2010 CFR

2010-07-01

... intravenous injection of a lethal substance or substances in a quantity sufficient to cause death, such... execution. 26.3 Section 26.3 Judicial Administration DEPARTMENT OF JUSTICE DEATH SENTENCES PROCEDURES Implementation of Death Sentences in Federal Cases § 26.3 Date, time, place, and method of execution. (a) Except...

5 CFR 843.205 - Designation of beneficiary-form and execution.

Code of Federal Regulations, 2010 CFR

2010-01-01

... execution. 843.205 Section 843.205 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL... One-time Payments § 843.205 Designation of beneficiary—form and execution. (a) A designation of..., corporation, or legal entity may be named as beneficiary. (e) A change of beneficiary may be made at any time...

Dissociable contributions of motor-execution and action-observation to intramanual transfer.

PubMed

Hayes, Spencer J; Elliott, Digby; Andrew, Matthew; Roberts, James W; Bennett, Simon J

2012-09-01

We examined the hypothesis that different processes and representations are associated with the learning of a movement sequence through motor-execution and action-observation. Following a pre-test in which participants attempted to achieve an absolute, and relative, time goal in a sequential goal-directed aiming movement, participants received either physical or observational practice with feedback. Post-test performance indicated that motor-execution and action-observation participants learned equally well. Participants then transferred to conditions where the gain between the limb movements and their visual consequences were manipulated. Under both bigger and smaller transfer conditions, motor-execution and action-observation participants exhibited similar intramanual transfer of absolute timing. However, participants in the action-observation group exhibited superior transfer of relative timing than the motor-execution group. These findings suggest that learning via action-observation is underpinned by a visual-spatial representation, while learning via motor-execution depends more on specific force-time planning (feed forward) and afferent processing associated with sensorimotor feedback. These behavioural effects are discussed with reference to neural processes associated with striatum, cerebellum and motor cortical regions (pre-motor cortex; SMA; pre-SMA).

Transition in the waiting-time distribution of price-change events in a global socioeconomic system

NASA Astrophysics Data System (ADS)

Zhao, Guannan; McDonald, Mark; Fenn, Dan; Williams, Stacy; Johnson, Nicholas; Johnson, Neil F.

2013-12-01

The goal of developing a firmer theoretical understanding of inhomogeneous temporal processes-in particular, the waiting times in some collective dynamical system-is attracting significant interest among physicists. Quantifying the deviations between the waiting-time distribution and the distribution generated by a random process may help unravel the feedback mechanisms that drive the underlying dynamics. We analyze the waiting-time distributions of high-frequency foreign exchange data for the best executable bid-ask prices across all major currencies. We find that the lognormal distribution yields a good overall fit for the waiting-time distribution between currency rate changes if both short and long waiting times are included. If we restrict our study to long waiting times, each currency pair’s distribution is consistent with a power-law tail with exponent near to 3.5. However, for short waiting times, the overall distribution resembles one generated by an archetypal complex systems model in which boundedly rational agents compete for limited resources. Our findings suggest that a gradual transition arises in trading behavior between a fast regime in which traders act in a boundedly rational way and a slower one in which traders’ decisions are driven by generic feedback mechanisms across multiple timescales and hence produce similar power-law tails irrespective of currency type.

Real-time trajectory optimization on parallel processors

NASA Technical Reports Server (NTRS)

Psiaki, Mark L.

1993-01-01

A parallel algorithm has been developed for rapidly solving trajectory optimization problems. The goal of the work has been to develop an algorithm that is suitable to do real-time, on-line optimal guidance through repeated solution of a trajectory optimization problem. The algorithm has been developed on an INTEL iPSC/860 message passing parallel processor. It uses a zero-order-hold discretization of a continuous-time problem and solves the resulting nonlinear programming problem using a custom-designed augmented Lagrangian nonlinear programming algorithm. The algorithm achieves parallelism of function, derivative, and search direction calculations through the principle of domain decomposition applied along the time axis. It has been encoded and tested on 3 example problems, the Goddard problem, the acceleration-limited, planar minimum-time to the origin problem, and a National Aerospace Plane minimum-fuel ascent guidance problem. Execution times as fast as 118 sec of wall clock time have been achieved for a 128-stage Goddard problem solved on 32 processors. A 32-stage minimum-time problem has been solved in 151 sec on 32 processors. A 32-stage National Aerospace Plane problem required 2 hours when solved on 32 processors. A speed-up factor of 7.2 has been achieved by using 32-nodes instead of 1-node to solve a 64-stage Goddard problem.

Estimation Accuracy on Execution Time of Run-Time Tasks in a Heterogeneous Distributed Environment

PubMed Central

Liu, Qi; Cai, Weidong; Jin, Dandan; Shen, Jian; Fu, Zhangjie; Liu, Xiaodong; Linge, Nigel

2016-01-01

Distributed Computing has achieved tremendous development since cloud computing was proposed in 2006, and played a vital role promoting rapid growth of data collecting and analysis models, e.g., Internet of things, Cyber-Physical Systems, Big Data Analytics, etc. Hadoop has become a data convergence platform for sensor networks. As one of the core components, MapReduce facilitates allocating, processing and mining of collected large-scale data, where speculative execution strategies help solve straggler problems. However, there is still no efficient solution for accurate estimation on execution time of run-time tasks, which can affect task allocation and distribution in MapReduce. In this paper, task execution data have been collected and employed for the estimation. A two-phase regression (TPR) method is proposed to predict the finishing time of each task accurately. Detailed data of each task have drawn interests with detailed analysis report being made. According to the results, the prediction accuracy of concurrent tasks’ execution time can be improved, in particular for some regular jobs. PMID:27589753

High-speed parallel implementation of a modified PBR algorithm on DSP-based EH topology

NASA Astrophysics Data System (ADS)

Rajan, K.; Patnaik, L. M.; Ramakrishna, J.

1997-08-01

Algebraic Reconstruction Technique (ART) is an age-old method used for solving the problem of three-dimensional (3-D) reconstruction from projections in electron microscopy and radiology. In medical applications, direct 3-D reconstruction is at the forefront of investigation. The simultaneous iterative reconstruction technique (SIRT) is an ART-type algorithm with the potential of generating in a few iterations tomographic images of a quality comparable to that of convolution backprojection (CBP) methods. Pixel-based reconstruction (PBR) is similar to SIRT reconstruction, and it has been shown that PBR algorithms give better quality pictures compared to those produced by SIRT algorithms. In this work, we propose a few modifications to the PBR algorithms. The modified algorithms are shown to give better quality pictures compared to PBR algorithms. The PBR algorithm and the modified PBR algorithms are highly compute intensive, Not many attempts have been made to reconstruct objects in the true 3-D sense because of the high computational overhead. In this study, we have developed parallel two-dimensional (2-D) and 3-D reconstruction algorithms based on modified PBR. We attempt to solve the two problems encountered by the PBR and modified PBR algorithms, i.e., the long computational time and the large memory requirements, by parallelizing the algorithm on a multiprocessor system. We investigate the possible task and data partitioning schemes by exploiting the potential parallelism in the PBR algorithm subject to minimizing the memory requirement. We have implemented an extended hypercube (EH) architecture for the high-speed execution of the 3-D reconstruction algorithm using the commercially available fast floating point digital signal processor (DSP) chips as the processing elements (PEs) and dual-port random access memories (DPR) as channels between the PEs. We discuss and compare the performances of the PBR algorithm on an IBM 6000 RISC workstation, on a Silicon Graphics Indigo 2 workstation, and on an EH system. The results show that an EH(3,1) using DSP chips as PEs executes the modified PBR algorithm about 100 times faster than an LBM 6000 RISC workstation. We have executed the algorithms on a 4-node IBM SP2 parallel computer. The results show that execution time of the algorithm on an EH(3,1) is better than that of a 4-node IBM SP2 system. The speed-up of an EH(3,1) system with eight PEs and one network controller is approximately 7.85.

Embedded algorithms within an FPGA-based system to process nonlinear time series data

NASA Astrophysics Data System (ADS)

Jones, Jonathan D.; Pei, Jin-Song; Tull, Monte P.

2008-03-01

This paper presents some preliminary results of an ongoing project. A pattern classification algorithm is being developed and embedded into a Field-Programmable Gate Array (FPGA) and microprocessor-based data processing core in this project. The goal is to enable and optimize the functionality of onboard data processing of nonlinear, nonstationary data for smart wireless sensing in structural health monitoring. Compared with traditional microprocessor-based systems, fast growing FPGA technology offers a more powerful, efficient, and flexible hardware platform including on-site (field-programmable) reconfiguration capability of hardware. An existing nonlinear identification algorithm is used as the baseline in this study. The implementation within a hardware-based system is presented in this paper, detailing the design requirements, validation, tradeoffs, optimization, and challenges in embedding this algorithm. An off-the-shelf high-level abstraction tool along with the Matlab/Simulink environment is utilized to program the FPGA, rather than coding the hardware description language (HDL) manually. The implementation is validated by comparing the simulation results with those from Matlab. In particular, the Hilbert Transform is embedded into the FPGA hardware and applied to the baseline algorithm as the centerpiece in processing nonlinear time histories and extracting instantaneous features of nonstationary dynamic data. The selection of proper numerical methods for the hardware execution of the selected identification algorithm and consideration of the fixed-point representation are elaborated. Other challenges include the issues of the timing in the hardware execution cycle of the design, resource consumption, approximation accuracy, and user flexibility of input data types limited by the simplicity of this preliminary design. Future work includes making an FPGA and microprocessor operate together to embed a further developed algorithm that yields better computational and power efficiency.

Pointing to double-step visual stimuli from a standing position: motor corrections when the speed-accuracy trade-off is unexpectedly modified in-flight. A breakdown of the perception-action coupling.

PubMed

Fautrelle, L; Barbieri, G; Ballay, Y; Bonnetblanc, F

2011-10-27

The time required to complete a fast and accurate movement is a function of its amplitude and the target size. This phenomenon refers to the well known speed-accuracy trade-off. Some interpretations have suggested that the speed-accuracy trade-off is already integrated into the movement planning phase. More specifically, pointing movements may be planned to minimize the variance of the final hand position. However, goal-directed movements can be altered at any time, if for instance, the target location is changed during execution. Thus, one possible limitation of these interpretations may be that they underestimate feedback processes. To further investigate this hypothesis we designed an experiment in which the speed-accuracy trade-off was unexpectedly varied at the hand movement onset by modifying separately the target distance or size, or by modifying both of them simultaneously. These pointing movements were executed from an upright standing position. Our main results showed that the movement time increased when there was a change to the size or location of the target. In addition, the terminal variability of finger position did not change. In other words, it showed that the movement velocity is modulated according to the target size and distance during motor programming or during the final approach, independently of the final variability of the hand position. It suggests that when the speed-accuracy trade-off is unexpectedly modified, terminal feedbacks based on intermediate representations of the endpoint velocity are used to monitor and control the hand displacement. There is clearly no obvious perception-action coupling in this case but rather intermediate processing that may be involved. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

An equation-free probabilistic steady-state approximation: dynamic application to the stochastic simulation of biochemical reaction networks.

PubMed

Salis, Howard; Kaznessis, Yiannis N

2005-12-01

Stochastic chemical kinetics more accurately describes the dynamics of "small" chemical systems, such as biological cells. Many real systems contain dynamical stiffness, which causes the exact stochastic simulation algorithm or other kinetic Monte Carlo methods to spend the majority of their time executing frequently occurring reaction events. Previous methods have successfully applied a type of probabilistic steady-state approximation by deriving an evolution equation, such as the chemical master equation, for the relaxed fast dynamics and using the solution of that equation to determine the slow dynamics. However, because the solution of the chemical master equation is limited to small, carefully selected, or linear reaction networks, an alternate equation-free method would be highly useful. We present a probabilistic steady-state approximation that separates the time scales of an arbitrary reaction network, detects the convergence of a marginal distribution to a quasi-steady-state, directly samples the underlying distribution, and uses those samples to accurately predict the state of the system, including the effects of the slow dynamics, at future times. The numerical method produces an accurate solution of both the fast and slow reaction dynamics while, for stiff systems, reducing the computational time by orders of magnitude. The developed theory makes no approximations on the shape or form of the underlying steady-state distribution and only assumes that it is ergodic. We demonstrate the accuracy and efficiency of the method using multiple interesting examples, including a highly nonlinear protein-protein interaction network. The developed theory may be applied to any type of kinetic Monte Carlo simulation to more efficiently simulate dynamically stiff systems, including existing exact, approximate, or hybrid stochastic simulation techniques.

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.

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Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-17

... Time. Contact Person for More Information: Stephen Llewellyn, Executive Officer, on (202) 663-4070. Dated: November 15, 2010. Stephen Llewellyn, Executive Officer, Executive Secretariat. This Notice...

Reorganization of large-scale cognitive networks during automation of imagination of a complex sequential movement.

PubMed

Sauvage, C; De Greef, N; Manto, M; Jissendi, P; Nioche, C; Habas, C

2015-04-01

We investigated the functional reconfiguration of the cerebral networks involved in imagination of sequential movements of the left foot, both performed at regular and fast speed after mental imagery training. Thirty-five volunteers were scanned with a 3T MRI while they imagined a sequence of ankle movements (dorsiflexion, plantar flexion, varus and valgus) before and after mental practice. Subjects were distributed in two groups: the first group executed regular movements whereas the second group made fast movements. We applied the general linear model (GLM) and model-free, exploratory tensorial independent component analytic (TICA) approaches to identify plastic post-training effects on brain activation. GLM showed that post-training imagination of movement was accompanied by a dual effect: a specific recruitment of a medial prefronto-cingulo-parietal circuit reminiscent of the default-mode network, with the left putamen, and a decreased activity of a lateral fronto-parietal network. Training-related subcortical changes only consisted in an increased activity in the left striatum. Unexpectedly, no difference was observed in the cerebellum. TICA also revealed involvement of the left executive network, and of the dorsal control executive network but no significant differences were found between pre- and post-training phases. Therefore, repetitive motor mental imagery induced specific putamen (motor rehearsal) recruitment that one previously observed during learning of overt movements, and, simultaneously, a specific shift of activity from the dorsolateral prefrontal cortex (attention, working memory) to the medial posterior parietal and cingulate cortices (mental imagery and memory rehearsal). Our data complement and confirm the notion that differential and coupled recruitment of cognitive networks can constitute a neural marker of training effects. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Maximizing Total QoS-Provisioning of Image Streams with Limited Energy Budget

NASA Astrophysics Data System (ADS)

Lee, Wan Yeon; Kim, Kyong Hoon; Ko, Young Woong

To fully utilize the limited battery energy of mobile electronic devices, we propose an adaptive adjustment method of processing quality for multiple image stream tasks running with widely varying execution times. This adjustment method completes the worst-case executions of the tasks with a given budget of energy, and maximizes the total reward value of processing quality obtained during their executions by exploiting the probability distribution of task execution times. The proposed method derives the maximum reward value for the tasks being executable with arbitrary processing quality, and near maximum value for the tasks being executable with a finite number of processing qualities. Our evaluation on a prototype system shows that the proposed method achieves larger reward values, by up to 57%, than the previous method.

Fast GPU-based computation of spatial multigrid multiframe LMEM for PET.

PubMed

Nassiri, Moulay Ali; Carrier, Jean-François; Després, Philippe

2015-09-01

Significant efforts were invested during the last decade to accelerate PET list-mode reconstructions, notably with GPU devices. However, the computation time per event is still relatively long, and the list-mode efficiency on the GPU is well below the histogram-mode efficiency. Since list-mode data are not arranged in any regular pattern, costly accesses to the GPU global memory can hardly be optimized and geometrical symmetries cannot be used. To overcome obstacles that limit the acceleration of reconstruction from list-mode on the GPU, a multigrid and multiframe approach of an expectation-maximization algorithm was developed. The reconstruction process is started during data acquisition, and calculations are executed concurrently on the GPU and the CPU, while the system matrix is computed on-the-fly. A new convergence criterion also was introduced, which is computationally more efficient on the GPU. The implementation was tested on a Tesla C2050 GPU device for a Gemini GXL PET system geometry. The results show that the proposed algorithm (multigrid and multiframe list-mode expectation-maximization, MGMF-LMEM) converges to the same solution as the LMEM algorithm more than three times faster. The execution time of the MGMF-LMEM algorithm was 1.1 s per million of events on the Tesla C2050 hardware used, for a reconstructed space of 188 x 188 x 57 voxels of 2 x 2 x 3.15 mm3. For 17- and 22-mm simulated hot lesions, the MGMF-LMEM algorithm led on the first iteration to contrast recovery coefficients (CRC) of more than 75 % of the maximum CRC while achieving a minimum in the relative mean square error. Therefore, the MGMF-LMEM algorithm can be used as a one-pass method to perform real-time reconstructions for low-count acquisitions, as in list-mode gated studies. The computation time for one iteration and 60 millions of events was approximately 66 s.

Falling from the top: the fired physician executive.

PubMed

Coile, R C; Tyler, J L

2000-01-01

Today's health care market is volatile, and the job of a physician executive is becoming more risky. Recognizing signs of trouble and taking immediate action is essential. Ten early warning signs that you could be fired are: (1) Net profits dip unexpectedly; (2) investment income can't cover operating losses; (3) bond rating is downgraded; (4) revenues are not rising as fast as costs; (5) senior executives leave the team; (6) wage increases don't improve nursing vacancy rate; (7) unions begin whisper campaign; (8) medical staff elect an SOB; (9) hospital is slapped with a costly lawsuit; and (10) recruiters call to check on your status. Physician executives are quickly learning what it takes to overcome tough challenges and prevent premature job termination: Communication; no-surprise performance; continuous monitoring of key indicators; openness and plain talk; and no-more-business-as-usual attitude. What can you do to make your job loss as painless as possible? (1) Negotiate a contract upfront; (2) don't lose your temper; (3) ask for your wish list quickly; (4) be reluctant to sue your former employer; (5) tell your family as soon as possible; (6) take only a brief vacation; (7) consider a temporary assignment; (8) be prepared to be re-employed by your former employer; and (9) keep a positive attitude.

A Differential Deficit in Time- versus Event-based Prospective Memory in Parkinson's Disease

PubMed Central

Raskin, Sarah A.; Woods, Steven Paul; Poquette, Amelia J.; McTaggart, April B.; Sethna, Jim; Williams, Rebecca C.; Tröster, Alexander I.

2010-01-01

Objective The aim of the current study was to clarify the nature and extent of impairment in time- versus event-based prospective memory in Parkinson's disease (PD). Prospective memory is thought to involve cognitive processes that are mediated by prefrontal systems and are executive in nature. Given that individuals with PD frequently show executive dysfunction, it is important to determine whether these individuals may have deficits in prospective memory that could impact daily functions, such as taking medications. Although it has been reported that individuals with PD evidence impairment in prospective memory, it is still unclear whether they show a greater deficit for time- versus event-based cues. Method Fifty-four individuals with PD and 34 demographically similar healthy adults were administered a standardized measure of prospective memory that allows for a direct comparison of time-based and event-based cues. In addition, participants were administered a series of standardized measures of retrospective memory and executive functions. Results Individuals with PD demonstrated impaired prospective memory performance compared to the healthy adults, with a greater impairment demonstrated for the time-based tasks. Time-based prospective memory performance was moderately correlated with measures of executive functioning, but only the Stroop Neuropsychological Screening Test emerged as a unique predictor in a linear regression. Conclusions Findings are interpreted within the context of McDaniel and Einstein's (2000) multi-process theory to suggest that individuals with PD experience particular difficulty executing a future intention when the cue to execute the prescribed intention requires higher levels of executive control. PMID:21090895

Development and Validation of a Fast, Accurate and Cost-Effective Aeroservoelastic Method on Advanced Parallel Computing Systems

NASA Technical Reports Server (NTRS)

Goodwin, Sabine A.; Raj, P.

1999-01-01

Progress to date towards the development and validation of a fast, accurate and cost-effective aeroelastic method for advanced parallel computing platforms such as the IBM SP2 and the SGI Origin 2000 is presented in this paper. The ENSAERO code, developed at the NASA-Ames Research Center has been selected for this effort. The code allows for the computation of aeroelastic responses by simultaneously integrating the Euler or Navier-Stokes equations and the modal structural equations of motion. To assess the computational performance and accuracy of the ENSAERO code, this paper reports the results of the Navier-Stokes simulations of the transonic flow over a flexible aeroelastic wing body configuration. In addition, a forced harmonic oscillation analysis in the frequency domain and an analysis in the time domain are done on a wing undergoing a rigid pitch and plunge motion. Finally, to demonstrate the ENSAERO flutter-analysis capability, aeroelastic Euler and Navier-Stokes computations on an L-1011 wind tunnel model including pylon, nacelle and empennage are underway. All computational solutions are compared with experimental data to assess the level of accuracy of ENSAERO. As the computations described above are performed, a meticulous log of computational performance in terms of wall clock time, execution speed, memory and disk storage is kept. Code scalability is also demonstrated by studying the impact of varying the number of processors on computational performance on the IBM SP2 and the Origin 2000 systems.

Similar Findings, Different Interpretations: A Response to the Commentary by Bootsma et al. (2010)

ERIC Educational Resources Information Center

van Soest, A. J.; Beek, Peter J.

2010-01-01

In this paper, we respond to the commentary by R. J. Bootsma, L. Fernandez, A. H. P. Morice, and G. Montagne (2010) concerning our original study on the role of vision during the execution of fast interceptive actions (A. J. van Soest, L. J. R. Casius, W. de Kok, M. Krijger, M. Meeder, and P. J. Beek, 2010), that was inspired by the seminal study…

ICPL: Intelligent Cooperative Planning and Learning for Multi-agent Systems

DTIC Science & Technology

2012-02-29

objective was to develop a new planning approach for teams!of multiple UAVs that tightly integrates learning and cooperative!control algorithms at... algorithms at multiple levels of the planning architecture. The research results enabled a team of mobile agents to learn to adapt and react to uncertainty in...expressive representation that incorporates feature conjunctions. Our algorithm is simple to implement, fast to execute, and can be combined with any

Statistics of Narrowband White Noise Derived from Clipped Broadband White Noise

DTIC Science & Technology

1992-02-01

e -26’lnN (7) A=1 with the inverse transform given by I N C(nAt) X D (lAf)e 2N. (8) The validity of this transform pair can be established by means...of the identity N I e (x"- ’ N = 8n.k+IN. (9) NARROWBAND STATISTICS The discrete Fourier transform and inverse transform can be executed via the fast

Executive functioning and processing speed in age-related differences in time estimation: a comparison of young, old, and very old adults.

PubMed

Baudouin, Alexia; Isingrini, Michel; Vanneste, Sandrine

2018-01-25

Age-related differences in time estimation were examined by comparing the temporal performance of young, young-old, and old-old adults, in relation to two major theories of cognitive aging: executive decline and cognitive slowing. We tested the hypothesis that processing speed and executive function are differentially involved in timing depending on the temporal task used. We also tested the assumption of greater age-related effects in time estimation in old-old participants. Participants performed two standard temporal tasks: duration production and duration reproduction. They also completed tests measuring executive function and processing speed. Findings supported the view that executive function is the best mediator of reproduction performance and inversely that processing speed is the best mediator of production performance. They also showed that young-old participants provide relatively accurate temporal judgments compared to old-old participants. These findings are discussed in terms of compensation mechanisms in aging.

A Multirate Control Strategy to the Slow Sensors Problem: An Interactive Simulation Tool for Controller Assisted Design

PubMed Central

Salt, Julián; Cuenca, Ángel; Palau, Francisco; Dormido, Sebastián

2014-01-01

In many control applications, the sensor technology used for the measurement of the variable to be controlled is not able to maintain a restricted sampling period. In this context, the assumption of regular and uniform sampling pattern is questionable. Moreover, if the control action updating can be faster than the output measurement frequency in order to fulfill the proposed closed loop behavior, the solution is usually a multirate controller. There are some known aspects to be careful of when a multirate system (MR) is going to be designed. The proper multiplicity between input-output sampling periods, the proper controller structure, the existence of ripples and others issues need to be considered. A useful way to save time and achieve good results is to have an assisted computer design tool. An interactive simulation tool to deal with MR seems to be the right solution. In this paper this kind of simulation application is presented. It allows an easy understanding of the performance degrading or improvement when changing the multirate sampling pattern parameters. The tool was developed using Sysquake, a Matlab-like language with fast execution and powerful graphic facilities. It can be delivered as an executable. In the paper a detailed explanation of MR treatment is also included and the design of four different MR controllers with flexible structure to be adapted to different schemes will also be presented. The Smith's predictor in these MR schemes is also explained, justified and used when time delays appear. Finally some interesting observations achieved using this interactive tool are included. PMID:24583971

Fast grasping of unknown objects using cylinder searching on a single point cloud

NASA Astrophysics Data System (ADS)

Lei, Qujiang; Wisse, Martijn

2017-03-01

Grasping of unknown objects with neither appearance data nor object models given in advance is very important for robots that work in an unfamiliar environment. The goal of this paper is to quickly synthesize an executable grasp for one unknown object by using cylinder searching on a single point cloud. Specifically, a 3D camera is first used to obtain a partial point cloud of the target unknown object. An original method is then employed to do post treatment on the partial point cloud to minimize the uncertainty which may lead to grasp failure. In order to accelerate the grasp searching, surface normal of the target object is then used to constrain the synthetization of the cylinder grasp candidates. Operability analysis is then used to select out all executable grasp candidates followed by force balance optimization to choose the most reliable grasp as the final grasp execution. In order to verify the effectiveness of our algorithm, Simulations on a Universal Robot arm UR5 and an under-actuated Lacquey Fetch gripper are used to examine the performance of this algorithm, and successful results are obtained.

Functional Role of Internal and External Visual Imagery: Preliminary Evidences from Pilates

PubMed Central

Montuori, Simone; Sorrentino, Pierpaolo; Belloni, Lidia; Sorrentino, Giuseppe

2018-01-01

The present study investigates whether a functional difference between the visualization of a sequence of movements in the perspective of the first- (internal VMI-I) or third- (external VMI-E) person exists, which might be relevant to promote learning. By using a mental chronometry experimental paradigm, we have compared the time or execution, imagination in the VMI-I perspective, and imagination in the VMI-E perspective of two kinds of Pilates exercises. The analysis was carried out in individuals with different levels of competence (expert, novice, and no-practice individuals). Our results showed that in the Expert group, in the VMI-I perspective, the imagination time was similar to the execution time, while in the VMI-E perspective, the imagination time was significantly lower than the execution time. An opposite pattern was found in the Novice group, in which the time of imagination was similar to that of execution only in the VMI-E perspective, while in the VMI-I perspective, the time of imagination was significantly lower than the time of execution. In the control group, the times of both modalities of imagination were significantly lower than the execution time for each exercise. The present data suggest that, while the VMI-I serves to train an already internalised gesture, the VMI-E perspective could be useful to learn, and then improve, the recently acquired sequence of movements. Moreover, visual imagery is not useful for individuals that lack a specific motor experience. The present data offer new insights in the application of mental training techniques, especially in field of sports. However, further investigations are needed to better understand the functional role of internal and external visual imagery. PMID:29849565

A single aerobic exercise session accelerates movement execution but not central processing.

PubMed

Beyer, Kit B; Sage, Michael D; Staines, W Richard; Middleton, Laura E; McIlroy, William E

2017-03-27

Previous research has demonstrated that aerobic exercise has disparate effects on speed of processing and movement execution. In simple and choice reaction tasks, aerobic exercise appears to increase speed of movement execution while speed of processing is unaffected. In the flanker task, aerobic exercise has been shown to reduce response time on incongruent trials more than congruent trials, purportedly reflecting a selective influence on speed of processing related to cognitive control. However, it is unclear how changes in speed of processing and movement execution contribute to these exercise-induced changes in response time during the flanker task. This study examined how a single session of aerobic exercise influences speed of processing and movement execution during a flanker task using electromyography to partition response time into reaction time and movement time, respectively. Movement time decreased during aerobic exercise regardless of flanker congruence but returned to pre-exercise levels immediately after exercise. Reaction time during incongruent flanker trials decreased over time in both an aerobic exercise and non-exercise control condition indicating it was not specifically influenced by exercise. This disparate influence of aerobic exercise on movement time and reaction time indicates the importance of partitioning response time when examining the influence of aerobic exercise on speed of processing. The decrease in reaction time over time independent of aerobic exercise indicates that interpreting pre-to-post exercise changes in behavior requires caution. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Prototyping Control and Data Acquisition for the ITER Neutral Beam Test Facility

NASA Astrophysics Data System (ADS)

Luchetta, Adriano; Manduchi, Gabriele; Taliercio, Cesare; Soppelsa, Anton; Paolucci, Francesco; Sartori, Filippo; Barbato, Paolo; Breda, Mauro; Capobianco, Roberto; Molon, Federico; Moressa, Modesto; Polato, Sandro; Simionato, Paola; Zampiva, Enrico

2013-10-01

The ITER Neutral Beam Test Facility will be the project's R&D facility for heating neutral beam injectors (HNB) for fusion research operating with H/D negative ions. Its mission is to develop technology to build the HNB prototype injector meeting the stringent HNB requirements (16.5 MW injection power, -1 MeV acceleration energy, 40 A ion current and one hour continuous operation). Two test-beds will be built in sequence in the facility: first SPIDER, the ion source test-bed, to optimize the negative ion source performance, second MITICA, the actual prototype injector, to optimize ion beam acceleration and neutralization. The SPIDER control and data acquisition system is under design. To validate the main architectural choices, a system prototype has been assembled and performance tests have been executed to assess the prototype's capability to meet the control and data acquisition system requirements. The prototype is based on open-source software frameworks running under Linux. EPICS is the slow control engine, MDSplus is the data handler and MARTe is the fast control manager. The prototype addresses low and high-frequency data acquisition, 10 kS/s and 10 MS/s respectively, camera image acquisition, data archiving, data streaming, data retrieval and visualization, real time fast control with 100 μs control cycle and supervisory control.

Predicting Operator Execution Times Using CogTool

NASA Technical Reports Server (NTRS)

Santiago-Espada, Yamira; Latorella, Kara A.

2013-01-01

Researchers and developers of NextGen systems can use predictive human performance modeling tools as an initial approach to obtain skilled user performance times analytically, before system testing with users. This paper describes the CogTool models for a two pilot crew executing two different types of a datalink clearance acceptance tasks, and on two different simulation platforms. The CogTool time estimates for accepting and executing Required Time of Arrival and Interval Management clearances were compared to empirical data observed in video tapes and registered in simulation files. Results indicate no statistically significant difference between empirical data and the CogTool predictions. A population comparison test found no significant differences between the CogTool estimates and the empirical execution times for any of the four test conditions. We discuss modeling caveats and considerations for applying CogTool to crew performance modeling in advanced cockpit environments.

Executive Compensation: Is It Better to be Lucky Than Good

DTIC Science & Technology

2013-07-30

are executives paid so much? Executive compensation has for years sparked interest from main street (citizens) to Wall Street (shareholders) to Capitol...from the luck of working for the right firm in the right industry at the right time. To clarify this muddied picture, Jeffrey Brookman at Idaho...luck best explains executive salaries . They ultimately conclude executives are compensated for their skills. Study Design and Method In their

Age-related differences in the motor planning of a lower leg target matching task.

PubMed

Davies, Brenda L; Gehringer, James E; Kurz, Max J

2015-12-01

While the development and execution of upper extremity motor plans have been well explored, little is known about how individuals plan and execute rapid, goal-directed motor tasks with the lower extremities. Furthermore, the amount of time needed to integrate the proper amount of visual and proprioceptive feedback before being able to accurately execute a goal-directed movement is not well understood; especially in children. Therefore, the purpose of this study was to initially interrogate how the amount of motor planning time provided to a child before movement execution may influence the preparation and execution of a lower leg goal-directed movement. The results displayed that the amount of pre-movement motor planning time provided may influence the reaction time and accuracy of a goal directed leg movement. All subjects in the study had longer reaction times and less accurate movements when no pre-movement motor planning time was provided. In addition, the children had slower reaction times, slower movements, and less accurate movements than the adults for all the presented targets and motor planning times. These results highlight that children may require more time to successfully plan a goal directed movement with the lower extremity. This suggests that children may potentially have less robust internal models than adults for these types of motor skills. Copyright © 2015 Elsevier B.V. All rights reserved.

Computational modelling of oxygenation processes in enzymes and biomimetic model complexes.

PubMed

de Visser, Sam P; Quesne, Matthew G; Martin, Bodo; Comba, Peter; Ryde, Ulf

2014-01-11

With computational resources becoming more efficient and more powerful and at the same time cheaper, computational methods have become more and more popular for studies on biochemical and biomimetic systems. Although large efforts from the scientific community have gone into exploring the possibilities of computational methods for studies on large biochemical systems, such studies are not without pitfalls and often cannot be routinely done but require expert execution. In this review we summarize and highlight advances in computational methodology and its application to enzymatic and biomimetic model complexes. In particular, we emphasize on topical and state-of-the-art methodologies that are able to either reproduce experimental findings, e.g., spectroscopic parameters and rate constants, accurately or make predictions of short-lived intermediates and fast reaction processes in nature. Moreover, we give examples of processes where certain computational methods dramatically fail.

NASTRAN internal improvements for 1992 release

NASA Technical Reports Server (NTRS)

Chan, Gordon C.

1992-01-01

The 1992 NASTRAN release incorporates a number of improvements transparent to users. The NASTRAN executable was made smaller by 70 pct. for the RISC base Unix machines by linking NASTRAN into a single program, freeing some 33 megabytes of system disc space that can be used by NASTRAN for solving larger problems. Some basic matrix operations, such as forward-backward substitution (FBS), multiply-add (MPYAD), matrix transpose, and fast eigensolution extraction routine (FEER), have been made more efficient by including new methods, new logic, new I/O techniques, and, in some cases, new subroutines. Some of the improvements provide ground work ready for system vectorization. These are finite element basic operations, and are used repeatedly in a finite element program such as NASTRAN. Any improvements on these basic operations can be translated into substantial cost and cpu time savings. NASTRAN is also discussed in various computer platforms.

An optical Fourier transform coprocessor with direct phase determination.

PubMed

Macfaden, Alexander J; Gordon, George S D; Wilkinson, Timothy D

2017-10-20

The Fourier transform is a ubiquitous mathematical operation which arises naturally in optics. We propose and demonstrate a practical method to optically evaluate a complex-to-complex discrete Fourier transform. By implementing the Fourier transform optically we can overcome the limiting O(nlogn) complexity of fast Fourier transform algorithms. Efficiently extracting the phase from the well-known optical Fourier transform is challenging. By appropriately decomposing the input and exploiting symmetries of the Fourier transform we are able to determine the phase directly from straightforward intensity measurements, creating an optical Fourier transform with O(n) apparent complexity. Performing larger optical Fourier transforms requires higher resolution spatial light modulators, but the execution time remains unchanged. This method could unlock the potential of the optical Fourier transform to permit 2D complex-to-complex discrete Fourier transforms with a performance that is currently untenable, with applications across information processing and computational physics.

Time-resolved determination of the potential of zero charge at polycrystalline Au/ionic liquid interfaces

NASA Astrophysics Data System (ADS)

Vargas-Barbosa, Nella M.; Roling, Bernhard

2018-05-01

The potential of zero charge (PZC) is a fundamental property that describes the electrode/electrolyte interface. The determination of the PZC at electrode/ionic liquid interfaces has been challenging due to the lack of models that fully describe these complex interfaces as well as the non-standardized approaches used to characterize them. In this work, we present a method that combines electrode immersion transient and impedance measurements for the determination of the PZC. This combined approach allows the distinction of the potential of zero free charge (pzfc), related to fast double layer charging on a millisecond timescale, from a potential of zero charge on a timescale of tens of seconds related to slower ion transport processes at the interface. Our method highlights the complementarity of these electrochemical techniques and the importance of selecting the correct timescale to execute experiments and interpret the results.

Fast polar decomposition of an arbitrary matrix

NASA Technical Reports Server (NTRS)

Higham, Nicholas J.; Schreiber, Robert S.

1988-01-01

The polar decomposition of an m x n matrix A of full rank, where m is greater than or equal to n, can be computed using a quadratically convergent algorithm. The algorithm is based on a Newton iteration involving a matrix inverse. With the use of a preliminary complete orthogonal decomposition the algorithm can be extended to arbitrary A. How to use the algorithm to compute the positive semi-definite square root of a Hermitian positive semi-definite matrix is described. A hybrid algorithm which adaptively switches from the matrix inversion based iteration to a matrix multiplication based iteration due to Kovarik, and to Bjorck and Bowie is formulated. The decision when to switch is made using a condition estimator. This matrix multiplication rich algorithm is shown to be more efficient on machines for which matrix multiplication can be executed 1.5 times faster than matrix inversion.

Relating Memory To Functional Performance In Normal Aging to Dementia Using Hierarchical Bayesian Cognitive Processing Models

PubMed Central

Shankle, William R.; Pooley, James P.; Steyvers, Mark; Hara, Junko; Mangrola, Tushar; Reisberg, Barry; Lee, Michael D.

2012-01-01

Determining how cognition affects functional abilities is important in Alzheimer’s disease and related disorders (ADRD). 280 patients (normal or ADRD) received a total of 1,514 assessments using the Functional Assessment Staging Test (FAST) procedure and the MCI Screen (MCIS). A hierarchical Bayesian cognitive processing (HBCP) model was created by embedding a signal detection theory (SDT) model of the MCIS delayed recognition memory task into a hierarchical Bayesian framework. The SDT model used latent parameters of discriminability (memory process) and response bias (executive function) to predict, simultaneously, recognition memory performance for each patient and each FAST severity group. The observed recognition memory data did not distinguish the six FAST severity stages, but the latent parameters completely separated them. The latent parameters were also used successfully to transform the ordinal FAST measure into a continuous measure reflecting the underlying continuum of functional severity. HBCP models applied to recognition memory data from clinical practice settings accurately translated a latent measure of cognition to a continuous measure of functional severity for both individuals and FAST groups. Such a translation links two levels of brain information processing, and may enable more accurate correlations with other levels, such as those characterized by biomarkers. PMID:22407225

Relating memory to functional performance in normal aging to dementia using hierarchical Bayesian cognitive processing models.

PubMed

Shankle, William R; Pooley, James P; Steyvers, Mark; Hara, Junko; Mangrola, Tushar; Reisberg, Barry; Lee, Michael D

2013-01-01

Determining how cognition affects functional abilities is important in Alzheimer disease and related disorders. A total of 280 patients (normal or Alzheimer disease and related disorders) received a total of 1514 assessments using the functional assessment staging test (FAST) procedure and the MCI Screen. A hierarchical Bayesian cognitive processing model was created by embedding a signal detection theory model of the MCI Screen-delayed recognition memory task into a hierarchical Bayesian framework. The signal detection theory model used latent parameters of discriminability (memory process) and response bias (executive function) to predict, simultaneously, recognition memory performance for each patient and each FAST severity group. The observed recognition memory data did not distinguish the 6 FAST severity stages, but the latent parameters completely separated them. The latent parameters were also used successfully to transform the ordinal FAST measure into a continuous measure reflecting the underlying continuum of functional severity. Hierarchical Bayesian cognitive processing models applied to recognition memory data from clinical practice settings accurately translated a latent measure of cognition into a continuous measure of functional severity for both individuals and FAST groups. Such a translation links 2 levels of brain information processing and may enable more accurate correlations with other levels, such as those characterized by biomarkers.

Hyperactivity in boys with attention-deficit/hyperactivity disorder (ADHD): The role of executive and non-executive functions.

PubMed

Hudec, Kristen L; Alderson, R Matt; Patros, Connor H G; Lea, Sarah E; Tarle, Stephanie J; Kasper, Lisa J

2015-01-01

Motor activity of boys (age 8-12 years) with (n=19) and without (n=18) ADHD was objectively measured with actigraphy across experimental conditions that varied with regard to demands on executive functions. Activity exhibited during two n-back (1-back, 2-back) working memory tasks was compared to activity during a choice-reaction time (CRT) task that placed relatively fewer demands on executive processes and during a simple reaction time (SRT) task that required mostly automatic processing with minimal executive demands. Results indicated that children in the ADHD group exhibited greater activity compared to children in the non-ADHD group. Further, both groups exhibited the greatest activity during conditions with high working memory demands, followed by the reaction time and control task conditions, respectively. The findings indicate that large-magnitude increases in motor activity are predominantly associated with increased demands on working memory, though demands on non-executive processes are sufficient to elicit small to moderate increases in motor activity as well. Published by Elsevier Ltd.

Kinematic Patterns Associated with the Vertical Force Produced during the Eggbeater Kick.

PubMed

Oliveira, Nuno; Chiu, Chuang-Yuan; Sanders, Ross H

2015-01-01

The purpose of this study was to determine the kinematic patterns that maximized the vertical force produced during the water polo eggbeater kick. Twelve water polo players were tested executing the eggbeater kick with the trunk aligned vertically and with the upper limbs above water while trying to maintain as high a position as possible out of the water for nine eggbeater kick cycles. Lower limb joint angular kinematics, pitch angles and speed of the feet were calculated. The vertical force produced during the eggbeater kick cycle was calculated using inverse dynamics for the independent lower body segments and combined upper body segments, and a participant-specific second-degree regression equation for the weight and buoyancy contributions. Vertical force normalized to body weight was associated with hip flexion (average, r = 0.691; maximum, r = 0.791; range of motion, r = 0.710), hip abduction (maximum, r = 0.654), knee flexion (average, r = 0.716; minimum, r = 0.653) and knee flexion-extension angular velocity (r = 0.758). Effective orientation of the hips resulted in fast horizontal motion of the feet with positive pitch angles. Vertical motion of the feet was negatively associated with vertical force. A multiple regression model comprising the non-collinear variables of maximum hip abduction, hip flexion range of motion and knee flexion angular velocity accounted for 81% of the variance in normalized vertical force. For high performance in the water polo, eggbeater kick players should execute fast horizontal motion with the feet by having large abduction and flexion of the hips, and fast extension and flexion of the knees.

Executive and arousal vigilance decrement in the context of the attentional networks: The ANTI-Vea task.

PubMed

Luna, Fernando Gabriel; Marino, Julián; Roca, Javier; Lupiáñez, Juan

2018-05-20

Vigilance is generally understood as the ability to detect infrequent critical events through long time periods. In tasks like the Sustained Attention to Response Task (SART), participants tend to detect fewer events across time, a phenomenon known as "vigilance decrement". However, vigilance might also involve sustaining a tonic arousal level. In the Psychomotor Vigilance Test (PVT), the vigilance decrement corresponds to an increment across time in both mean and variability of reaction time. The present study aimed to develop a single task -Attentional Networks Test for Interactions and Vigilance - executive and arousal components (ANTI-Vea)- to simultaneously assess both components of vigilance (i.e., the executive vigilance as in the SART, and the arousal vigilance as in the PVT), while measuring the classic attentional functions (phasic alertness, orienting, and executive control). In Experiment #1, the executive vigilance decrement was found as an increment in response bias. In Experiment #2, this result was replicated, and the arousal vigilance decrement was simultaneously observed as an increment in reaction time. The ANTI-Vea solves some issues observed in the previous ANTI-V task with the executive vigilance measure (e.g., a low hit rate and no vigilance decrement). Furthermore, the new ANTI-Vea task assesses both components of vigilance together with others typical attentional functions. The new attentional networks test developed here may be useful to provide a better understanding of the human attentional system. The role of sensitivity and response bias in the executive vigilance decrement are discussed. Copyright © 2018 Elsevier B.V. All rights reserved.

CASPER Version 2.0

NASA Technical Reports Server (NTRS)

Chien, Steve; Rabideau, Gregg; Tran, Daniel; Knight, Russell; Chouinard, Caroline; Estlin, Tara; Gaines, Daniel; Clement, Bradley; Barrett, Anthony

2007-01-01

CASPER is designed to perform automated planning of interdependent activities within a system subject to requirements, constraints, and limitations on resources. In contradistinction to the traditional concept of batch planning followed by execution, CASPER implements a concept of continuous planning and replanning in response to unanticipated changes (including failures), integrated with execution. Improvements over other, similar software that have been incorporated into CASPER version 2.0 include an enhanced executable interface to facilitate integration with a wide range of execution software systems and supporting software libraries; features to support execution while reasoning about urgency, importance, and impending deadlines; features that enable accommodation to a wide range of computing environments that include various central processing units and random- access-memory capacities; and improved generic time-server and time-control features.

Executive Functioning Mediates the Effect of Behavioral Problems on Depression in Mothers of Children With Developmental Disabilities

PubMed Central

Chan, Wai; Smith, Leann E.; Greenberg, Jan S.; Hong, Jinkuk; Mailick, Marsha R.

2017-01-01

The present investigation explored long-term relationships of behavioral symptoms of adolescents and adults with developmental disabilities with the mental health of their mothers. Fragile X premutation carrier mothers of an adolescent or adult child with fragile X syndrome (n = 95), and mothers of a grown child with autism (n = 213) were included. Behavioral symptoms at Time 1 were hypothesized to predict maternal depressive symptoms at Time 3 via maternal executive dysfunction at Time 2. Results provided support for the mediating pathway of executive dysfunction. Additionally, the association of behavioral symptoms with executive dysfunction differed across the two groups, suggesting that premutation carriers may be more susceptible to caregiving stress due to their genotype. PMID:28095060

A Platform for Developing Autonomy Technologies for Small Military Robots

DTIC Science & Technology

2008-12-01

angular increments around the disk so described. A line scanner oriented so the plane of detected points is horizontal (e.g., the axis about which...behaviors can be implemented. Thus it will contain the custom scripts , executables, and data that compose the actual behavior of the robot. Currently, the...operating system was constructed to be relatively small and boot fast. Debian GNU/Linux, however, provides an installation script that downloads a

Automatic recognition of vector and parallel operations in a higher level language

NASA Technical Reports Server (NTRS)

Schneck, P. B.

1971-01-01

A compiler for recognizing statements of a FORTRAN program which are suited for fast execution on a parallel or pipeline machine such as Illiac-4, Star or ASC is described. The technique employs interval analysis to provide flow information to the vector/parallel recognizer. Where profitable the compiler changes scalar variables to subscripted variables. The output of the compiler is an extension to FORTRAN which shows parallel and vector operations explicitly.

The balanced scorecard--measures that drive performance.

PubMed

Kaplan, R S; Norton, D P

1992-01-01

Frustrated by the inadequacies of traditional performance measurement systems, some managers have abandoned financial measures like return on equity and earnings per share. "Make operational improvements and the numbers will follow," the argument goes. But managers do not want to choose between financial and operational measures. Executives want a balanced presentation of measures that allow them to view the company from several perspectives simultaneously. During a year-long research project with 12 companies at the leading edge of performance measurement, the authors developed a "balanced scorecard," a new performance measurement system that gives top managers a fast but comprehensive view of the business. The balanced scorecard includes financial measures that tell the results of actions already taken. And it complements those financial measures with three sets of operational measures having to do with customer satisfaction, internal processes, and the organization's ability to learn and improve--the activities that drive future financial performance. Managers can create a balanced scorecard by translating their company's strategy and mission statements into specific goals and measures. To create the part of the scorecard that focuses on the customer perspective, for example, executives at Electronic Circuits Inc. established general goals for customer performance: get standard products to market sooner, improve customers' time-to-market, become customers' supplier of choice through partnerships, and develop innovative products tailored to customer needs. Managers translated these elements of strategy into four specific goals and identified a measure for each.

Expected Utility Distributions for Flexible, Contingent Execution

NASA Technical Reports Server (NTRS)

Bresina, John L.; Washington, Richard

2000-01-01

This paper presents a method for using expected utility distributions in the execution of flexible, contingent plans. A utility distribution maps the possible start times of an action to the expected utility of the plan suffix starting with that action. The contingent plan encodes a tree of possible courses of action and includes flexible temporal constraints and resource constraints. When execution reaches a branch point, the eligible option with the highest expected utility at that point in time is selected. The utility distributions make this selection sensitive to the runtime context, yet still efficient. Our approach uses predictions of action duration uncertainty as well as expectations of resource usage and availability to determine when an action can execute and with what probability. Execution windows and probabilities inevitably change as execution proceeds, but such changes do not invalidate the cached utility distributions, thus, dynamic updating of utility information is minimized.

Estimating the executive demands of a one-back choice reaction time task by means of the selective interference paradigm.

PubMed

Szmalec, Arnaud; Vandierendonck, André

2007-08-01

The present study proposes a new executive task, the one-back choice reaction time (RT) task, and implements the selective interference paradigm to estimate the executive demands of the processing components involved in this task. Based on the similarities between a one-back choice RT task and the n-back updating task, it was hypothesized that one-back delaying of a choice reaction involves executive control. In three experiments, framed within Baddeley's (1986) working-memory model, a one-back choice RT task, a choice RT task, articulatory suppression, and matrix tapping were performed concurrently with primary tasks involving verbal, visuospatial, and executive processing. The results demonstrate that one-back delaying of a choice reaction interferes with tasks requiring executive control, while the potential interference at the level of the verbal or visuospatial working memory slave systems remains minimal.

STOP-IT: Windows executable software for the stop-signal paradigm.

PubMed

Verbruggen, Frederick; Logan, Gordon D; Stevens, Michaël A

2008-05-01

The stop-signal paradigm is a useful tool for the investigation of response inhibition. In this paradigm, subjects are instructed to respond as fast as possible to a stimulus unless a stop signal is presented after a variable delay. However, programming the stop-signal task is typically considered to be difficult. To overcome this issue, we present software called STOP-IT, for running the stop-signal task, as well as an additional analyzing program called ANALYZE-IT. The main advantage of both programs is that they are a precompiled executable, and for basic use there is no need for additional programming. STOP-IT and ANALYZE-IT are completely based on free software, are distributed under the GNU General Public License, and are available at the personal Web sites of the first two authors or at expsy.ugent.be/tscope/stop.html.

Flexibility of orthographic and graphomotor coordination during a handwritten copy task: effect of time pressure

PubMed Central

Sausset, Solen; Lambert, Eric; Olive, Thierry

2013-01-01

The coordination of the various processes involved in language production is a subject of keen debate in writing research. Some authors hold that writing processes can be flexibly coordinated according to task demands, whereas others claim that process coordination is entirely inflexible. For instance, orthographic planning has been shown to be resource-dependent during handwriting, but inflexible in typing, even under time pressure. The present study therefore went one step further in studying flexibility in the coordination of orthographic processing and graphomotor execution, by measuring the impact of time pressure during a handwritten copy task. Orthographic and graphomotor processes were observed via syllable processing. Writers copied out two- and three-syllable words three times in a row, with and without time pressure. Latencies and letter measures at syllable boundaries were analyzed. We hypothesized that if coordination is flexible and varies according to task demands, it should be modified by time pressure, affecting both latency before execution and duration of execution. We therefore predicted that the extent of syllable processing before execution would be reduced under time pressure and, as a consequence, syllable effects during execution would be more salient. Results showed, however, that time pressure interacted neither with syllable number nor with syllable structure. Accordingly, syllable processing appears to remain the same regardless of time pressure. The flexibility of process coordination during handwriting is discussed, as is the operationalization of time pressure constraints. PMID:24319435

Fast structure similarity searches among protein models: efficient clustering of protein fragments

PubMed Central

2012-01-01

Background For many predictive applications a large number of models is generated and later clustered in subsets based on structure similarity. In most clustering algorithms an all-vs-all root mean square deviation (RMSD) comparison is performed. Most of the time is typically spent on comparison of non-similar structures. For sets with more than, say, 10,000 models this procedure is very time-consuming and alternative faster algorithms, restricting comparisons only to most similar structures would be useful. Results We exploit the inverse triangle inequality on the RMSD between two structures given the RMSDs with a third structure. The lower bound on RMSD may be used, when restricting the search of similarity to a reasonably low RMSD threshold value, to speed up similarity searches significantly. Tests are performed on large sets of decoys which are widely used as test cases for predictive methods, with a speed-up of up to 100 times with respect to all-vs-all comparison depending on the set and parameters used. Sample applications are shown. Conclusions The algorithm presented here allows fast comparison of large data sets of structures with limited memory requirements. As an example of application we present clustering of more than 100000 fragments of length 5 from the top500H dataset into few hundred representative fragments. A more realistic scenario is provided by the search of similarity within the very large decoy sets used for the tests. Other applications regard filtering nearly-indentical conformation in selected CASP9 datasets and clustering molecular dynamics snapshots. Availability A linux executable and a Perl script with examples are given in the supplementary material (Additional file 1). The source code is available upon request from the authors. PMID:22642815

Software Aids Visualization of Computed Unsteady Flow

NASA Technical Reports Server (NTRS)

Kao, David; Kenwright, David

2003-01-01

Unsteady Flow Analysis Toolkit (UFAT) is a computer program that synthesizes motions of time-dependent flows represented by very large sets of data generated in computational fluid dynamics simulations. Prior to the development of UFAT, it was necessary to rely on static, single-snapshot depictions of time-dependent flows generated by flow-visualization software designed for steady flows. Whereas it typically takes weeks to analyze the results of a largescale unsteady-flow simulation by use of steady-flow visualization software, the analysis time is reduced to hours when UFAT is used. UFAT can be used to generate graphical objects of flow visualization results using multi-block curvilinear grids in the format of a previously developed NASA data-visualization program, PLOT3D. These graphical objects can be rendered using FAST, another popular flow visualization software developed at NASA. Flow-visualization techniques that can be exploited by use of UFAT include time-dependent tracking of particles, detection of vortex cores, extractions of stream ribbons and surfaces, and tetrahedral decomposition for optimal particle tracking. Unique computational features of UFAT include capabilities for automatic (batch) processing, restart, memory mapping, and parallel processing. These capabilities significantly reduce analysis time and storage requirements, relative to those of prior flow-visualization software. UFAT can be executed on a variety of supercomputers.

Executive Mind, Timely Action.

ERIC Educational Resources Information Center

Torbert, William R.

1983-01-01

The idea of "Executive Mind" carries with it the notion of purposeful and effective action. Part I of this paper characterizes three complements to "Executive Mind"--"Observing Mind,""Theorizing Mind," and "Passionate Mind"--and offers historical figures exemplifying all four types. The concluding…

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.

Atomicity violation detection using access interleaving invariants

DOEpatents

Zhou, Yuanyuan; Lu, Shan; Tucek, Joseph Andrew

2013-09-10

During execution of a program, the situation where the atomicity of a pair of instructions that are to be executed atomically is violated is identified, and a bug is detected as occurring in the program at the pair of instructions. The pairs of instructions that are to be executed atomically can be identified in different manners, such as by executing a program multiple times and using the results of those executions to automatically identify the pairs of instructions.

Two approaches to estimating the effect of parenting on the development of executive function in early childhood.

PubMed

Blair, Clancy; Raver, C Cybele; Berry, Daniel J

2014-02-01

In the current article, we contrast 2 analytical approaches to estimate the relation of parenting to executive function development in a sample of 1,292 children assessed longitudinally between the ages of 36 and 60 months of age. Children were administered a newly developed and validated battery of 6 executive function tasks tapping inhibitory control, working memory, and attention shifting. Residualized change analysis indicated that higher quality parenting as indicated by higher scores on widely used measures of parenting at both earlier and later time points predicted more positive gain in executive function at 60 months. Latent change score models in which parenting and executive function over time were held to standards of longitudinal measurement invariance provided additional evidence of the association between change in parenting quality and change in executive function. In these models, cross-lagged paths indicated that in addition to parenting predicting change in executive function, executive function bidirectionally predicted change in parenting quality. Results were robust with the addition of covariates, including child sex, race, maternal education, and household income-to-need. Strengths and drawbacks of the 2 analytic approaches are discussed, and the findings are considered in light of emerging methodological innovations for testing the extent to which executive function is malleable and open to the influence of experience.

Fast MPEG-CDVS Encoder With GPU-CPU Hybrid Computing

NASA Astrophysics Data System (ADS)

Duan, Ling-Yu; Sun, Wei; Zhang, Xinfeng; Wang, Shiqi; Chen, Jie; Yin, Jianxiong; See, Simon; Huang, Tiejun; Kot, Alex C.; Gao, Wen

2018-05-01

The compact descriptors for visual search (CDVS) standard from ISO/IEC moving pictures experts group (MPEG) has succeeded in enabling the interoperability for efficient and effective image retrieval by standardizing the bitstream syntax of compact feature descriptors. However, the intensive computation of CDVS encoder unfortunately hinders its widely deployment in industry for large-scale visual search. In this paper, we revisit the merits of low complexity design of CDVS core techniques and present a very fast CDVS encoder by leveraging the massive parallel execution resources of GPU. We elegantly shift the computation-intensive and parallel-friendly modules to the state-of-the-arts GPU platforms, in which the thread block allocation and the memory access are jointly optimized to eliminate performance loss. In addition, those operations with heavy data dependence are allocated to CPU to resolve the extra but non-necessary computation burden for GPU. Furthermore, we have demonstrated the proposed fast CDVS encoder can work well with those convolution neural network approaches which has harmoniously leveraged the advantages of GPU platforms, and yielded significant performance improvements. Comprehensive experimental results over benchmarks are evaluated, which has shown that the fast CDVS encoder using GPU-CPU hybrid computing is promising for scalable visual search.

Analysis of slow- and fast-α band asymmetry during performance of a saccadic eye movement task: dissociation between memory- and attention-driven systems.

PubMed

Sanfim, Antonio; Velasques, Bruna; Machado, Sergio; Arias-Carrión, Oscar; Paes, Flávia; Teixeira, Silmar; Santos, Joana Luz; Bittencourt, Juliana; Basile, Luis F; Cagy, Mauricio; Piedade, Roberto; Sack, Alexander T; Nardi, Antonio Egídio; Ribeiro, Pedro

2012-01-15

This study aimed at analyzing the relationship between slow- and fast-alpha asymmetry within frontal cortex and the planning, execution and voluntary control of saccadic eye movements (SEM), and quantitative electroencephalography (qEEG) was recorded using a 20-channel EEG system in 12 healthy participants performing a fixed (i.e., memory-driven) and a random SEM (i.e., stimulus-driven) condition. We find main effects for SEM condition in slow- and fast-alpha asymmetry at electrodes F3-F4, which are located over premotor cortex, specifically a negative asymmetry between conditions. When analyzing electrodes F7-F8, which are located over prefrontal cortex, we found a main effect for condition in slow-alpha asymmetry, particularly a positive asymmetry between conditions. In conclusion, the present approach supports the association of slow- and fast-alpha bands with the planning and preparation of SEM, and the specific role of these sub-bands for both, the attention network and the coordination and integration of sensory information with a (oculo)-motor response. Copyright © 2011 Elsevier B.V. All rights reserved.

Fast software-based volume rendering using multimedia instructions on PC platforms and its application to virtual endoscopy

NASA Astrophysics Data System (ADS)

Mori, Kensaku; Suenaga, Yasuhito; Toriwaki, Jun-ichiro

2003-05-01

This paper describes a software-based fast volume rendering (VolR) method on a PC platform by using multimedia instructions, such as SIMD instructions, which are currently available in PCs' CPUs. This method achieves fast rendering speed through highly optimizing software rather than an improved rendering algorithm. In volume rendering using a ray casting method, the system requires fast execution of the following processes: (a) interpolation of voxel or color values at sample points, (b) computation of normal vectors (gray-level gradient vectors), (c) calculation of shaded values obtained by dot-products of normal vectors and light source direction vectors, (d) memory access to a huge area, and (e) efficient ray skipping at translucent regions. The proposed software implements these fundamental processes in volume rending by using special instruction sets for multimedia processing. The proposed software can generate virtual endoscopic images of a 3-D volume of 512x512x489 voxel size by volume rendering with perspective projection, specular reflection, and on-the-fly normal vector computation on a conventional PC without any special hardware at thirteen frames per second. Semi-translucent display is also possible.

Relationships of Attention and Executive Functions to Oral Language, Reading, and Writing Skills and Systems in Middle Childhood and Early Adolescence.

PubMed

Berninger, Virginia; Abbott, Robert; Cook, Clayton R; Nagy, William

Relationships between attention/executive functions and language learning were investigated in students in Grades 4 to 9 ( N = 88) with and without specific learning disabilities (SLDs) in multiword syntax in oral and written language (OWL LD), word reading and spelling (dyslexia), and subword letter writing (dysgraphia). Prior attention-deficit/hyperactivity disorder (ADHD) diagnosis was correlated only with impaired handwriting. Parental ratings of inattention, but not hyperactivity, correlated with measures of written language but not oral language. Sustaining switching attention correlated with writing the alphabet from memory in manuscript or by keyboard and fast copying of a sentence with all the letters of the alphabet. Multiple regressions based on a principal component for composites of multiple levels of language (subword, word, and syntax/text) showed that measures of attention and executive function involving language processing rather than ratings of attention and executive function not specifically related to language accounted for more variance and identified more unique predictors in the composite outcomes for oral language, reading, and writing systems. Inhibition related to focused attention uniquely predicted outcomes for the oral language system. Findings are discussed in reference to implications for assessing and teaching students who are still learning to pay attention to heard and written language and self-regulate their language learning during middle childhood and adolescence.

5 CFR 317.306 - Conversion of employees under time limited appointments.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Conversion of employees under time... CIVIL SERVICE REGULATIONS EMPLOYMENT IN THE SENIOR EXECUTIVE SERVICE Conversion to the Senior Executive Service § 317.306 Conversion of employees under time limited appointments. (a) Coverage. This section...

17 CFR 37.900 - Core Principle 9-Timely publication of trading information.

Code of Federal Regulations, 2014 CFR

2014-04-01

... publication of trading information. 37.900 Section 37.900 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION SWAP EXECUTION FACILITIES Timely Publication of Trading Information § 37.900 Core Principle 9—Timely publication of trading information. (a) In general. The swap execution facility shall...

Putting time into proof outlines

NASA Technical Reports Server (NTRS)

Schneider, Fred B.; Bloom, Bard; Marzullo, Keith

1991-01-01

A logic for reasoning about timing of concurrent programs is presented. The logic is based on proof outlines and can handle maximal parallelism as well as resource-constrained execution environments. The correctness proof for a mutual exclusion protocol that uses execution timings in a subtle way illustrates the logic in action.

Parallel program debugging with flowback analysis

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

Choi, Jongdeok.

1989-01-01

This thesis describes the design and implementation of an integrated debugging system for parallel programs running on shared memory multi-processors. The goal of the debugging system is to present to the programmer a graphical view of the dynamic program dependences while keeping the execution-time overhead low. The author first describes the use of flowback analysis to provide information on causal relationship between events in a programs' execution without re-executing the program for debugging. Execution time overhead is kept low by recording only a small amount of trace during a program's execution. He uses semantic analysis and a technique called incrementalmore » tracing to keep the time and space overhead low. As part of the semantic analysis, he uses a static program dependence graph structure that reduces the amount of work done at compile time and takes advantage of the dynamic information produced during execution time. The cornerstone of the incremental tracing concept is to generate a coarse trace during execution and fill incrementally, during the interactive portion of the debugging session, the gap between the information gathered in the coarse trace and the information needed to do the flowback analysis using the coarse trace. Then, he describes how to extend the flowback analysis to parallel programs. The flowback analysis can span process boundaries; i.e., the most recent modification to a shared variable might be traced to a different process than the one that contains the current reference. The static and dynamic program dependence graphs of the individual processes are tied together with synchronization and data dependence information to form complete graphs that represent the entire program.« less

A Hierarchical Auction-Based Mechanism for Real-Time Resource Allocation in Cloud Robotic Systems.

PubMed

Wang, Lujia; Liu, Ming; Meng, Max Q-H

2017-02-01

Cloud computing enables users to share computing resources on-demand. The cloud computing framework cannot be directly mapped to cloud robotic systems with ad hoc networks since cloud robotic systems have additional constraints such as limited bandwidth and dynamic structure. However, most multirobotic applications with cooperative control adopt this decentralized approach to avoid a single point of failure. Robots need to continuously update intensive data to execute tasks in a coordinated manner, which implies real-time requirements. Thus, a resource allocation strategy is required, especially in such resource-constrained environments. This paper proposes a hierarchical auction-based mechanism, namely link quality matrix (LQM) auction, which is suitable for ad hoc networks by introducing a link quality indicator. The proposed algorithm produces a fast and robust method that is accurate and scalable. It reduces both global communication and unnecessary repeated computation. The proposed method is designed for firm real-time resource retrieval for physical multirobot systems. A joint surveillance scenario empirically validates the proposed mechanism by assessing several practical metrics. The results show that the proposed LQM auction outperforms state-of-the-art algorithms for resource allocation.

A new and inexpensive non-bit-for-bit solution reproducibility test based on time step convergence (TSC1.0)

NASA Astrophysics Data System (ADS)

Wan, Hui; Zhang, Kai; Rasch, Philip J.; Singh, Balwinder; Chen, Xingyuan; Edwards, Jim

2017-02-01

A test procedure is proposed for identifying numerically significant solution changes in evolution equations used in atmospheric models. The test issues a fail signal when any code modifications or computing environment changes lead to solution differences that exceed the known time step sensitivity of the reference model. Initial evidence is provided using the Community Atmosphere Model (CAM) version 5.3 that the proposed procedure can be used to distinguish rounding-level solution changes from impacts of compiler optimization or parameter perturbation, which are known to cause substantial differences in the simulated climate. The test is not exhaustive since it does not detect issues associated with diagnostic calculations that do not feedback to the model state variables. Nevertheless, it provides a practical and objective way to assess the significance of solution changes. The short simulation length implies low computational cost. The independence between ensemble members allows for parallel execution of all simulations, thus facilitating fast turnaround. The new method is simple to implement since it does not require any code modifications. We expect that the same methodology can be used for any geophysical model to which the concept of time step convergence is applicable.

Effective conductivity of suspensions of hard spheres by Brownian motion simulation

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

Chan Kim, I.; Torquato, S.

1991-02-15

A generalized Brownian motion simulation technique developed by Kim and Torquato (J. Appl. Phys. {bold 68}, 3892 (1990)) is applied to compute exactly'' the effective conductivity {sigma}{sub {ital e}} of heterogeneous media composed of regular and random distributions of hard spheres of conductivity {sigma}{sub 2} in a matrix of conductivity {sigma}{sub 1} for virtually the entire volume fraction range and for several values of the conductivity ratio {alpha}={sigma}{sub 2}/{sigma}{sub 1}, including superconducting spheres ({alpha}={infinity}) and perfectly insulating spheres ({alpha}=0). A key feature of the procedure is the use of {ital first}-{ital passage}-{ital time} equations in the two homogeneous phases andmore » at the two-phase interface. The method is shown to yield {sigma}{sub {ital e}} accurately with a comparatively fast execution time. The microstructure-sensitive analytical approximation of {sigma}{sub {ital e}} for dispersions derived by Torquato (J. Appl. Phys. {bold 58}, 3790 (1985)) is shown to be in excellent agreement with our data for random suspensions for the wide range of conditions reported here.« less

A Multiagent Energy Management System for a Small Microgrid Equipped with Power Sources and Energy Storage Units

NASA Astrophysics Data System (ADS)

Radziszewska, Weronika; Nahorski, Zbigniew

An Energy Management System (EMS) for a small microgrid is presented, with both demand and production side management. The microgrid is equipped with renewable and controllable power sources (like a micro gas turbine), energy storage units (batteries and flywheels). Energy load is partially scheduled to avoid extreme peaks of power demand and to possibly match forecasted energy supply from the renewable power sources. To balance the energy in the network on line, a multiagent system is used. Intelligent agents of each device are proactively acting towards balancing the energy in the network, and at the same time optimizing the cost of operation of the whole system. A semi-market mechanism is used to match a demand and a production of the energy. Simulations show that the time of reaching a balanced state does not exceed 1 s, which is fast enough to let execute proper balancing actions, e.g. change an operating point of a controllable energy source. Simulators of sources and consumption devices were implemented in order to carry out exhaustive tests.

Malware detection and analysis

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

Chiang, Ken; Lloyd, Levi; Crussell, Jonathan

Embodiments of the invention describe systems and methods for malicious software detection and analysis. A binary executable comprising obfuscated malware on a host device may be received, and incident data indicating a time when the binary executable was received and identifying processes operating on the host device may be recorded. The binary executable is analyzed via a scalable plurality of execution environments, including one or more non-virtual execution environments and one or more virtual execution environments, to generate runtime data and deobfuscation data attributable to the binary executable. At least some of the runtime data and deobfuscation data attributable tomore » the binary executable is stored in a shared database, while at least some of the incident data is stored in a private, non-shared database.« less

Software for Automation of Real-Time Agents, Version 2

NASA Technical Reports Server (NTRS)

Fisher, Forest; Estlin, Tara; Gaines, Daniel; Schaffer, Steve; Chouinard, Caroline; Engelhardt, Barbara; Wilklow, Colette; Mutz, Darren; Knight, Russell; Rabideau, Gregg;

Development of a Computer Architecture to Support the Optical Plume Anomaly Detection (OPAD) System

NASA Technical Reports Server (NTRS)

Katsinis, Constantine

1996-01-01

The NASA OPAD spectrometer system relies heavily on extensive software which repetitively extracts spectral information from the engine plume and reports the amounts of metals which are present in the plume. The development of this software is at a sufficiently advanced stage where it can be used in actual engine tests to provide valuable data on engine operation and health. This activity will continue and, in addition, the OPAD system is planned to be used in flight aboard space vehicles. The two implementations, test-stand and in-flight, may have some differing requirements. For example, the data stored during a test-stand experiment are much more extensive than in the in-flight case. In both cases though, the majority of the requirements are similar. New data from the spectrograph is generated at a rate of once every 0.5 sec or faster. All processing must be completed within this period of time to maintain real-time performance. Every 0.5 sec, the OPAD system must report the amounts of specific metals within the engine plume, given the spectral data. At present, the software in the OPAD system performs this function by solving the inverse problem. It uses powerful physics-based computational models (the SPECTRA code), which receive amounts of metals as inputs to produce the spectral data that would have been observed, had the same metal amounts been present in the engine plume. During the experiment, for every spectrum that is observed, an initial approximation is performed using neural networks to establish an initial metal composition which approximates as accurately as possible the real one. Then, using optimization techniques, the SPECTRA code is repetitively used to produce a fit to the data, by adjusting the metal input amounts until the produced spectrum matches the observed one to within a given level of tolerance. This iterative solution to the original problem of determining the metal composition in the plume requires a relatively long period of time to execute the software in a modern single-processor workstation, and therefore real-time operation is currently not possible. A different number of iterations may be required to perform spectral data fitting per spectral sample. Yet, the OPAD system must be designed to maintain real-time performance in all cases. Although faster single-processor workstations are available for execution of the fitting and SPECTRA software, this option is unattractive due to the excessive cost associated with very fast workstations and also due to the fact that such hardware is not easily expandable to accommodate future versions of the software which may require more processing power. Initial research has already demonstrated that the OPAD software can take advantage of a parallel computer architecture to achieve the necessary speedup. Current work has improved the software by converting it into a form which is easily parallelizable. Timing experiments have been performed to establish the computational complexity and execution speed of major components of the software. This work provides the foundation of future work which will create a fully parallel version of the software executing in a shared-memory multiprocessor system.

Human whole-body reaching in normal gravity and microgravity reveals a strong temporal coordination between postural and focal task components.

PubMed

Patron, Jerome; Stapley, Paul; Pozzo, Thierry

2005-08-01

Previous experiments by our group in normal gravity (1 G) have revealed spatial relationships between postural and focal components of whole-body reaching and pointing movements. We suggested that these relationships could be explained partly through the use of gravity to displace the CoM and attain the object or target position. In this study we compared human whole-body reaching in 1 G and microgravity (0 G) in order to more fully investigate how gravity contributes to strategies adopted for task execution and to determine possible invariant temporal relationships between multiple segments. Whole-body reaching movements made from the standing position in two experimental conditions of execution speed (naturally paced and as fast as possible) were recorded during periods of 1 G and 0 G in parabolic flight. Overall, at each speed of reaching, movement times were significantly slower when performed in 0 G than in 1 G for two of the three subjects, but all subjects were able to produce significantly faster movements in 0 G than in 1 G. Despite similar general trends across subjects observed in 1 G, angular displacements of reaching movements performed in 0 G differed greatly between subjects. There were changes at all joints, but above all at the shoulder and the ankle. However, despite a high intersubject and intratrial variability in 0 G, in both gravity conditions all subjects demonstrated times to peak curvilinear velocity for the finger (end effector) and the whole-body centre of mass (CoM) that coincided, regardless of the speed of execution. Moreover, cross-correlations between multiple segment curvilinear velocities and those of the CoM revealed tight, highly correlated temporal relationships between segments proximal to the CoM (which was expected). However, for more distal segments, the correlations were weaker, and the movements lagged behind movements of the CoM. The major and most interesting finding of this study was that although the finger was the most distal within the segment chain, with respect to the CoM, it was highly correlated with the CoM (0.99--0.98, all conditions) and with no time lag. Despite the large intersubject and inter-environmental variability recorded in this study, temporal relationships between postural task components (CoM displacements) and those of the focal movement (end-effector trajectory) were consistently conserved.

Naps Enhance Executive Attention in Preschool-Aged Children.

PubMed

Cremone, Amanda; McDermott, Jennifer M; Spencer, Rebecca M C

2017-09-01

Executive attention is impaired following sleep loss in school-aged children, adolescents, and adults. Whether naps improve attention relative to nap deprivation in preschool-aged children is unknown. The aim of this study was to compare executive attention in preschool children following a nap and an interval of wake. Sixty-nine children, 35-70 months of age, completed a Flanker task to assess executive attention following a nap and an equivalent interval of wake. Overall, accuracy was greater after the nap compared with the wake interval. Reaction time(s) did not differ between the nap and wake intervals. Results did not differ between children who napped consistently and those who napped inconsistently, suggesting that naps benefit executive attention of preschoolers regardless of nap habituality. These results indicate that naps enhance attention in preschool children. As executive attention supports executive functioning and learning, nap promotion may improve early education outcomes. © The Author 2017. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Timing, sequencing, and executive control in repetitive movement production.

PubMed

Krampe, Ralf Th; Mayr, Ulrich; Kliegl, Reinhold

2005-06-01

The authors demonstrate that the timing and sequencing of target durations require low-level timing and executive control. Sixteen young (M-sub(age) = 19 years) and 16 older (M-sub(age) = 70 years) adults participated in 2 experiments. In Experiment 1, individual mean-variance functions for low-level timing (isochronous tapping) and the sequencing of multiple targets (rhythm production) revealed (a) a dissociation of low-level timing and sequencing in both age groups, (b) negligible age differences for low-level timing, and (c) large age differences for sequencing. Experiment 2 supported the distinction between low-level timing and executive functions: Selection against a dominant rhythm and switching between rhythms impaired performances in both age groups and induced pronounced perseveration of the dominant pattern in older adults. ((c) 2005 APA, all rights reserved).

Ten Years of Change in Executive Education.

ERIC Educational Resources Information Center

Bolt, James F.

1993-01-01

As recently as the 1980s, most companies did not pay much attention to executive education. In the 1990s, many see executive education as a must for revamping competitive strategies, increasing productivity, improving quality, reducing cycle time, and revitalizing corporate culture. (Author/JOW)

Revisiting nurse turnover costs: adjusting for inflation.

PubMed

Jones, Cheryl Bland

2008-01-01

Organizational knowledge of nurse turnover costs is important, but gathering these data frequently may not always be feasible in today's fast-paced and complex healthcare environment. The author presents a method to inflation adjust baseline nurse turnover costs using the Consumer Price Index. This approach allows nurse executives to gain current knowledge of organizational nurse turnover costs when primary data collection is not practical and to determine costs and potential savings if nurse retention investments are made.

A Review of Sparsity-Based Methods for Analysing Radar Returns from Helicopter Rotor Blades

DTIC Science & Technology

2016-09-01

UNCLASSIFIED A Review of Sparsity-Based Methods for Analysing Radar Returns from Helicopter Rotor Blades Ngoc Hung Nguyen 1, Hai-Tan Tran 2, Kutluyıl...TR–3292 ABSTRACT Radar imaging of rotating blade -like objects, such as helicopter rotors, using narrowband radar has lately been of significant...Methods for Analysing Radar Returns from Helicopter Rotor Blades Executive Summary Signal analysis and radar imaging of fast-rotating objects such as

Shortened preoperative fasting for prevention of complications associated with laparoscopic cholecystectomy: a meta-analysis.

PubMed

Xu, Duo; Zhu, Xuejiao; Xu, Yuan; Zhang, Liqing

2017-02-01

Objective Routine fasting (12 h) is always applied before laparoscopic cholecystectomy, but prolonged preoperative fasting causes thirst, hunger, and irritability as well as dehydration, low blood glucose, insulin resistance and other adverse reactions. We assessed the safety and efficacy of a shortened preoperative fasting period in patients undergoing laparoscopic cholecystectomy. Methods We searched PubMed, Embase and Cochrane Central Register of Controlled Trials up to 20 November 2015 and selected controlled trials with a shortened fasting time before laparoscopic cholecystectomy. We assessed the results by performing a meta-analysis using a variety of outcome measures and investigated the heterogeneity by subgroup analysis. Results Eleven trials were included. Forest plots showed that a shortened fasting time reduced the operative risk and patient discomfort. A shortened fasting time also reduced postoperative nausea and vomiting as well as operative vomiting. With respect to glucose metabolism, a shortened fasting time significantly reduced abnormalities in the ratio of insulin sensitivity. The C-reactive protein concentration was also reduced by a shortened fasting time. Conclusions A shortened preoperative fasting time increases patients' postoperative comfort, improves insulin resistance, and reduces stress responses. This evidence supports the clinical application of a shortened fasting time before laparoscopic cholecystectomy.

Individual differences in executive control relate to metaphor processing: an eye movement study of sentence reading

PubMed Central

Columbus, Georgie; Sheikh, Naveed A.; Côté-Lecaldare, Marilena; Häuser, Katja; Baum, Shari R.; Titone, Debra

2015-01-01

Metaphors are common elements of language that allow us to creatively stretch the limits of word meaning. However, metaphors vary in their degree of novelty, which determines whether people must create new meanings on-line or retrieve previously known metaphorical meanings from memory. Such variations affect the degree to which general cognitive capacities such as executive control are required for successful comprehension. We investigated whether individual differences in executive control relate to metaphor processing using eye movement measures of reading. Thirty-nine participants read sentences including metaphors or idioms, another form of figurative language that is more likely to rely on meaning retrieval. They also completed the AX-CPT, a domain-general executive control task. In Experiment 1, we examined sentences containing metaphorical or literal uses of verbs, presented with or without prior context. In Experiment 2, we examined sentences containing idioms or literal phrases for the same participants to determine whether the link to executive control was qualitatively similar or different to Experiment 1. When metaphors were low familiar, all people read verbs used as metaphors more slowly than verbs used literally (this difference was smaller for high familiar metaphors). Executive control capacity modulated this pattern in that high executive control readers spent more time reading verbs when a prior context forced a particular interpretation (metaphorical or literal), and they had faster total metaphor reading times when there was a prior context. Interestingly, executive control did not relate to idiom processing for the same readers. Here, all readers had faster total reading times for high familiar idioms than literal phrases. Thus, executive control relates to metaphor but not idiom processing for these readers, and for the particular metaphor and idiom reading manipulations presented. PMID:25628557

Individual Differences in Childhood Sleep Problems Predict Later Cognitive Executive Control

PubMed Central

Friedman, Naomi P.; Corley, Robin P.; Hewitt, John K.; Wright, Kenneth P.

2009-01-01

Study Objective: To determine whether individual differences in developmental patterns of general sleep problems are associated with 3 executive function abilities—inhibiting, updating working memory, and task shifting—in late adolescence. Participants: 916 twins (465 female, 451 male) and parents from the Colorado Longitudinal Twin Study. Measurements and Results: Parents reported their children's sleep problems at ages 4 years, 5 y, 7 y, and 9–16 y based on a 7-item scale from the Child-Behavior Checklist; a subset of children (n = 568) completed laboratory assessments of executive functions at age 17. Latent variable growth curve analyses were used to model individual differences in longitudinal trajectories of childhood sleep problems. Sleep problems declined over time, with ~70% of children having ≥ 1 problem at age 4 and ~33% of children at age 16. However, significant individual differences in both the initial levels of problems (intercept) and changes across time (slope) were observed. When executive function latent variables were added to the model, the intercept did not significantly correlate with the later executive function latent variables; however, the slope variable significantly (P < 0.05) negatively correlated with inhibiting (r = −0.27) and updating (r = −0.21), but not shifting (r = −0.10) abilities. Further analyses suggested that the slope variable predicted the variance common to the 3 executive functions (r = −0.29). Conclusions: Early levels of sleep problems do not seem to have appreciable implications for later executive functioning. However, individuals whose sleep problems decrease more across time show better general executive control in late adolescence. Citation: Friedman NP; Corley RP; Hewitt JK; Wright KP. Individual differences in childhood sleep problems predict later cognitive executive control. SLEEP 2009;32(3):323-333. PMID:19294952

Individual differences in executive control relate to metaphor processing: an eye movement study of sentence reading.

PubMed

Columbus, Georgie; Sheikh, Naveed A; Côté-Lecaldare, Marilena; Häuser, Katja; Baum, Shari R; Titone, Debra

2014-01-01

Metaphors are common elements of language that allow us to creatively stretch the limits of word meaning. However, metaphors vary in their degree of novelty, which determines whether people must create new meanings on-line or retrieve previously known metaphorical meanings from memory. Such variations affect the degree to which general cognitive capacities such as executive control are required for successful comprehension. We investigated whether individual differences in executive control relate to metaphor processing using eye movement measures of reading. Thirty-nine participants read sentences including metaphors or idioms, another form of figurative language that is more likely to rely on meaning retrieval. They also completed the AX-CPT, a domain-general executive control task. In Experiment 1, we examined sentences containing metaphorical or literal uses of verbs, presented with or without prior context. In Experiment 2, we examined sentences containing idioms or literal phrases for the same participants to determine whether the link to executive control was qualitatively similar or different to Experiment 1. When metaphors were low familiar, all people read verbs used as metaphors more slowly than verbs used literally (this difference was smaller for high familiar metaphors). Executive control capacity modulated this pattern in that high executive control readers spent more time reading verbs when a prior context forced a particular interpretation (metaphorical or literal), and they had faster total metaphor reading times when there was a prior context. Interestingly, executive control did not relate to idiom processing for the same readers. Here, all readers had faster total reading times for high familiar idioms than literal phrases. Thus, executive control relates to metaphor but not idiom processing for these readers, and for the particular metaphor and idiom reading manipulations presented.

Executive functioning independently predicts self-rated health and improvement in self-rated health over time among community-dwelling older adults.

PubMed

McHugh, Joanna Edel; Lawlor, Brian A

2016-01-01

Self-rated health, as distinct from objective measures of health, is a clinically informative metric among older adults. The purpose of our study was to examine the cognitive and psychosocial factors associated with self-rated health. 624 participants over the age of 60 were assessed at baseline, and of these, 510 were contacted for a follow-up two years later. Measures of executive function and self-rated health were assessed at baseline, and self-rated health was assessed at follow-up. We employed multiple linear regression analyses to investigate the relationship between executive functioning and self-rated health, while controlling for demographic, psychosocial and biological variables. Controlling for other relevant variables, executive functioning independently and solely predicted self-rated health, both at a cross-sectional level, and also over time. Loneliness was also found to cross-sectionally predict self-rated health, although this relationship was not present at a longitudinal level. Older adults' self-rated health may be related to their executive functioning and to their loneliness. Self-rated health appeared to improve over time, and the extent of this improvement was also related to executive functioning at baseline. Self-rated health may be a judgement made of one's functioning, especially executive functioning, which changes with age and therefore may be particularly salient in the reflections of older adults.

Heterogeneous computing architecture for fast detection of SNP-SNP interactions.

PubMed

Sluga, Davor; Curk, Tomaz; Zupan, Blaz; Lotric, Uros

2014-06-25

The extent of data in a typical genome-wide association study (GWAS) poses considerable computational challenges to software tools for gene-gene interaction discovery. Exhaustive evaluation of all interactions among hundreds of thousands to millions of single nucleotide polymorphisms (SNPs) may require weeks or even months of computation. Massively parallel hardware within a modern Graphic Processing Unit (GPU) and Many Integrated Core (MIC) coprocessors can shorten the run time considerably. While the utility of GPU-based implementations in bioinformatics has been well studied, MIC architecture has been introduced only recently and may provide a number of comparative advantages that have yet to be explored and tested. We have developed a heterogeneous, GPU and Intel MIC-accelerated software module for SNP-SNP interaction discovery to replace the previously single-threaded computational core in the interactive web-based data exploration program SNPsyn. We report on differences between these two modern massively parallel architectures and their software environments. Their utility resulted in an order of magnitude shorter execution times when compared to the single-threaded CPU implementation. GPU implementation on a single Nvidia Tesla K20 runs twice as fast as that for the MIC architecture-based Xeon Phi P5110 coprocessor, but also requires considerably more programming effort. General purpose GPUs are a mature platform with large amounts of computing power capable of tackling inherently parallel problems, but can prove demanding for the programmer. On the other hand the new MIC architecture, albeit lacking in performance reduces the programming effort and makes it up with a more general architecture suitable for a wider range of problems.

Heterogeneous computing architecture for fast detection of SNP-SNP interactions

PubMed Central

2014-01-01

Background The extent of data in a typical genome-wide association study (GWAS) poses considerable computational challenges to software tools for gene-gene interaction discovery. Exhaustive evaluation of all interactions among hundreds of thousands to millions of single nucleotide polymorphisms (SNPs) may require weeks or even months of computation. Massively parallel hardware within a modern Graphic Processing Unit (GPU) and Many Integrated Core (MIC) coprocessors can shorten the run time considerably. While the utility of GPU-based implementations in bioinformatics has been well studied, MIC architecture has been introduced only recently and may provide a number of comparative advantages that have yet to be explored and tested. Results We have developed a heterogeneous, GPU and Intel MIC-accelerated software module for SNP-SNP interaction discovery to replace the previously single-threaded computational core in the interactive web-based data exploration program SNPsyn. We report on differences between these two modern massively parallel architectures and their software environments. Their utility resulted in an order of magnitude shorter execution times when compared to the single-threaded CPU implementation. GPU implementation on a single Nvidia Tesla K20 runs twice as fast as that for the MIC architecture-based Xeon Phi P5110 coprocessor, but also requires considerably more programming effort. Conclusions General purpose GPUs are a mature platform with large amounts of computing power capable of tackling inherently parallel problems, but can prove demanding for the programmer. On the other hand the new MIC architecture, albeit lacking in performance reduces the programming effort and makes it up with a more general architecture suitable for a wider range of problems. PMID:24964802

GOSSIP: a method for fast and accurate global alignment of protein structures.

PubMed

Kifer, I; Nussinov, R; Wolfson, H J

2011-04-01

The database of known protein structures (PDB) is increasing rapidly. This results in a growing need for methods that can cope with the vast amount of structural data. To analyze the accumulating data, it is important to have a fast tool for identifying similar structures and clustering them by structural resemblance. Several excellent tools have been developed for the comparison of protein structures. These usually address the task of local structure alignment, an important yet computationally intensive problem due to its complexity. It is difficult to use such tools for comparing a large number of structures to each other at a reasonable time. Here we present GOSSIP, a novel method for a global all-against-all alignment of any set of protein structures. The method detects similarities between structures down to a certain cutoff (a parameter of the program), hence allowing it to detect similar structures at a much higher speed than local structure alignment methods. GOSSIP compares many structures in times which are several orders of magnitude faster than well-known available structure alignment servers, and it is also faster than a database scanning method. We evaluate GOSSIP both on a dataset of short structural fragments and on two large sequence-diverse structural benchmarks. Our conclusions are that for a threshold of 0.6 and above, the speed of GOSSIP is obtained with no compromise of the accuracy of the alignments or of the number of detected global similarities. A server, as well as an executable for download, are available at http://bioinfo3d.cs.tau.ac.il/gossip/.

Individual differences in the components of children's and adults' information processing for simple symbolic and non-symbolic numeric decisions.

PubMed

Thompson, Clarissa A; Ratcliff, Roger; McKoon, Gail

2016-10-01

How do speed and accuracy trade off, and what components of information processing develop as children and adults make simple numeric comparisons? Data from symbolic and non-symbolic number tasks were collected from 19 first graders (Mage=7.12 years), 26 second/third graders (Mage=8.20 years), 27 fourth/fifth graders (Mage=10.46 years), and 19 seventh/eighth graders (Mage=13.22 years). The non-symbolic task asked children to decide whether an array of asterisks had a larger or smaller number than 50, and the symbolic task asked whether a two-digit number was greater than or less than 50. We used a diffusion model analysis to estimate components of processing in tasks from accuracy, correct and error response times, and response time (RT) distributions. Participants who were accurate on one task were accurate on the other task, and participants who made fast decisions on one task made fast decisions on the other task. Older participants extracted a higher quality of information from the stimulus arrays, were more willing to make a decision, and were faster at encoding, transforming the stimulus representation, and executing their responses. Individual participants' accuracy and RTs were uncorrelated. Drift rate and boundary settings were significantly related across tasks, but they were unrelated to each other. Accuracy was mainly determined by drift rate, and RT was mainly determined by boundary separation. We concluded that RT and accuracy operate largely independently. Copyright © 2016 Elsevier Inc. All rights reserved.

78 FR 71695 - Self-Regulatory Organizations; Financial Industry Regulatory Authority, Inc.; Notice of Filing of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-29

... inquiries and investigations. The current approach of requiring members to report the reference time instead... proposing amendments to the equity trade reporting rules relating to reporting (i) an additional time field for specified trades, (ii) execution time in milliseconds, (iii) reversals, (iv) trades executed on...

Computer architecture for efficient algorithmic executions in real-time systems: New technology for avionics systems and advanced space vehicles

NASA Technical Reports Server (NTRS)

Carroll, Chester C.; Youngblood, John N.; Saha, Aindam

1987-01-01

Improvements and advances in the development of computer architecture now provide innovative technology for the recasting of traditional sequential solutions into high-performance, low-cost, parallel system to increase system performance. Research conducted in development of specialized computer architecture for the algorithmic execution of an avionics system, guidance and control problem in real time is described. A comprehensive treatment of both the hardware and software structures of a customized computer which performs real-time computation of guidance commands with updated estimates of target motion and time-to-go is presented. An optimal, real-time allocation algorithm was developed which maps the algorithmic tasks onto the processing elements. This allocation is based on the critical path analysis. The final stage is the design and development of the hardware structures suitable for the efficient execution of the allocated task graph. The processing element is designed for rapid execution of the allocated tasks. Fault tolerance is a key feature of the overall architecture. Parallel numerical integration techniques, tasks definitions, and allocation algorithms are discussed. The parallel implementation is analytically verified and the experimental results are presented. The design of the data-driven computer architecture, customized for the execution of the particular algorithm, is discussed.

Computer architecture for efficient algorithmic executions in real-time systems: new technology for avionics systems and advanced space vehicles

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

Carroll, C.C.; Youngblood, J.N.; Saha, A.

1987-12-01

Improvements and advances in the development of computer architecture now provide innovative technology for the recasting of traditional sequential solutions into high-performance, low-cost, parallel system to increase system performance. Research conducted in development of specialized computer architecture for the algorithmic execution of an avionics system, guidance and control problem in real time is described. A comprehensive treatment of both the hardware and software structures of a customized computer which performs real-time computation of guidance commands with updated estimates of target motion and time-to-go is presented. An optimal, real-time allocation algorithm was developed which maps the algorithmic tasks onto the processingmore » elements. This allocation is based on the critical path analysis. The final stage is the design and development of the hardware structures suitable for the efficient execution of the allocated task graph. The processing element is designed for rapid execution of the allocated tasks. Fault tolerance is a key feature of the overall architecture. Parallel numerical integration techniques, tasks definitions, and allocation algorithms are discussed. The parallel implementation is analytically verified and the experimental results are presented. The design of the data-driven computer architecture, customized for the execution of the particular algorithm, is discussed.« less

Accelerating next generation sequencing data analysis with system level optimizations.

PubMed

Kathiresan, Nagarajan; Temanni, Ramzi; Almabrazi, Hakeem; Syed, Najeeb; Jithesh, Puthen V; Al-Ali, Rashid

2017-08-22

Next generation sequencing (NGS) data analysis is highly compute intensive. In-memory computing, vectorization, bulk data transfer, CPU frequency scaling are some of the hardware features in the modern computing architectures. To get the best execution time and utilize these hardware features, it is necessary to tune the system level parameters before running the application. We studied the GATK-HaplotypeCaller which is part of common NGS workflows, that consume more than 43% of the total execution time. Multiple GATK 3.x versions were benchmarked and the execution time of HaplotypeCaller was optimized by various system level parameters which included: (i) tuning the parallel garbage collection and kernel shared memory to simulate in-memory computing, (ii) architecture-specific tuning in the PairHMM library for vectorization, (iii) including Java 1.8 features through GATK source code compilation and building a runtime environment for parallel sorting and bulk data transfer (iv) the default 'on-demand' mode of CPU frequency is over-clocked by using 'performance-mode' to accelerate the Java multi-threads. As a result, the HaplotypeCaller execution time was reduced by 82.66% in GATK 3.3 and 42.61% in GATK 3.7. Overall, the execution time of NGS pipeline was reduced to 70.60% and 34.14% for GATK 3.3 and GATK 3.7 respectively.

Evaluation of Fast-Time Wake Vortex Prediction Models

NASA Technical Reports Server (NTRS)

Proctor, Fred H.; Hamilton, David W.

2009-01-01

Current fast-time wake models are reviewed and three basic types are defined. Predictions from several of the fast-time models are compared. Previous statistical evaluations of the APA-Sarpkaya and D2P fast-time models are discussed. Root Mean Square errors between fast-time model predictions and Lidar wake measurements are examined for a 24 hr period at Denver International Airport. Shortcomings in current methodology for evaluating wake errors are also discussed.

Conceptualization and Operationalization of Executive Function

ERIC Educational Resources Information Center

Baggetta, Peter; Alexander, Patricia A.

2016-01-01

Executive function is comprised of different behavioral and cognitive elements and is considered to play a significant role in learning and academic achievement. Educational researchers frequently study the construct. However, because of its complexity functionally, the research on executive function can at times be both confusing and…

A design fix to supervisory control for fault-tolerant scheduling of real-time multiprocessor systems with aperiodic tasks

NASA Astrophysics Data System (ADS)

Devaraj, Rajesh; Sarkar, Arnab; Biswas, Santosh

2015-11-01

In the article 'Supervisory control for fault-tolerant scheduling of real-time multiprocessor systems with aperiodic tasks', Park and Cho presented a systematic way of computing a largest fault-tolerant and schedulable language that provides information on whether the scheduler (i.e., supervisor) should accept or reject a newly arrived aperiodic task. The computation of such a language is mainly dependent on the task execution model presented in their paper. However, the task execution model is unable to capture the situation when the fault of a processor occurs even before the task has arrived. Consequently, a task execution model that does not capture this fact may possibly be assigned for execution on a faulty processor. This problem has been illustrated with an appropriate example. Then, the task execution model of Park and Cho has been modified to strengthen the requirement that none of the tasks are assigned for execution on a faulty processor.

Automatic analysis (aa): efficient neuroimaging workflows and parallel processing using Matlab and XML.

PubMed

Cusack, Rhodri; Vicente-Grabovetsky, Alejandro; Mitchell, Daniel J; Wild, Conor J; Auer, Tibor; Linke, Annika C; Peelle, Jonathan E

2014-01-01

Recent years have seen neuroimaging data sets becoming richer, with larger cohorts of participants, a greater variety of acquisition techniques, and increasingly complex analyses. These advances have made data analysis pipelines complicated to set up and run (increasing the risk of human error) and time consuming to execute (restricting what analyses are attempted). Here we present an open-source framework, automatic analysis (aa), to address these concerns. Human efficiency is increased by making code modular and reusable, and managing its execution with a processing engine that tracks what has been completed and what needs to be (re)done. Analysis is accelerated by optional parallel processing of independent tasks on cluster or cloud computing resources. A pipeline comprises a series of modules that each perform a specific task. The processing engine keeps track of the data, calculating a map of upstream and downstream dependencies for each module. Existing modules are available for many analysis tasks, such as SPM-based fMRI preprocessing, individual and group level statistics, voxel-based morphometry, tractography, and multi-voxel pattern analyses (MVPA). However, aa also allows for full customization, and encourages efficient management of code: new modules may be written with only a small code overhead. aa has been used by more than 50 researchers in hundreds of neuroimaging studies comprising thousands of subjects. It has been found to be robust, fast, and efficient, for simple-single subject studies up to multimodal pipelines on hundreds of subjects. It is attractive to both novice and experienced users. aa can reduce the amount of time neuroimaging laboratories spend performing analyses and reduce errors, expanding the range of scientific questions it is practical to address.

Motor dysfunction and alterations in glutathione concentration, cholinesterase activity, and BDNF expression in substantia nigra pars compacta in rats with pedunculopontine lesion.

PubMed

Blanco-Lezcano, Lisette; Jimenez-Martin, Javier; Díaz-Hung, Mei-Li; Alberti-Amador, Esteban; Wong-Guerra, Maylin; González-Fraguela, Ma Elena; Estupiñán-Díaz, Bárbara; Serrano-Sánchez, Teresa; Francis-Turner, Liliana; Delgado-Ocaña, Susana; Núñez-Figueredo, Yanier; Vega-Hurtado, Yamilé; Fernández-Jiménez, Isabel

2017-04-21

Pedunculopontine nucleus (PPN) has been considered a critically important region in the regulation of some of the physiological functions that fail during the progression of Parkinson's disease (PD). In this paper, the effects of unilateral neurotoxic lesion of the PPN [through the injection of N-methyl-d-aspartate (NMDA) solution (concentration: 0.1M; volume: 0.5µL)] in motor execution and gait disorders and the changes in cellular and molecular indicators in rat nigral tissue were evaluated. The motor execution was assessed using the beam test (BT) and the gait disorders by footprint test. Glutathione (GSH) concentrations, acetyl cholinesterase enzymatic activity (AChE EA), and brain-derived neurotrophic factor (BDNF) mRNA expression in nigral tissue were analyzed. NMDA-lesioned rats showed fine motor dysfunction with a significant increase in the slow (p≤0.01) and fast movement (p≤0.01) time and in path deviation (p≤0.01) on the smaller diameter beams. Moreover, NMDA-lesioned rats exhibited an imprecise path with moments of advances and setbacks, alternating with left and right deviations, suspensions, and inverted positions. Footprint test revealed slight gait disorders, which were manifested by a reduction in the left and right stride lengths, the intra-step distance, and the support area (p≤0.01). Biochemical studies showed that 48h after the PPN neurotoxic injury, the GSH concentrations and BDNF expression were significantly increased (p≤0.01). These variables returned to normal values 7days after the PPN lesion; the AChE EA showed a significant increase at this time. These functional changes in nigral tissue could be a plastic responses associated with early PD. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Language-motor interference reflected in MEG beta oscillations.

PubMed

Klepp, Anne; Niccolai, Valentina; Buccino, Giovanni; Schnitzler, Alfons; Biermann-Ruben, Katja

2015-04-01

The involvement of the brain's motor system in action-related language processing can lead to overt interference with simultaneous action execution. The aim of the current study was to find evidence for this behavioural interference effect and to investigate its neurophysiological correlates using oscillatory MEG analysis. Subjects performed a semantic decision task on single action verbs, describing actions executed with the hands or the feet, and abstract verbs. Right hand button press responses were given for concrete verbs only. Therefore, longer response latencies for hand compared to foot verbs should reflect interference. We found interference effects to depend on verb imageability: overall response latencies for hand verbs did not differ significantly from foot verbs. However, imageability interacted with effector: while response latencies to hand and foot verbs with low imageability were equally fast, those for highly imageable hand verbs were longer than for highly imageable foot verbs. The difference is reflected in motor-related MEG beta band power suppression, which was weaker for highly imageable hand verbs compared with highly imageable foot verbs. This provides a putative neuronal mechanism for language-motor interference where the involvement of cortical hand motor areas in hand verb processing interacts with the typical beta suppression seen before movements. We found that the facilitatory effect of higher imageability on action verb processing time is perturbed when verb and motor response relate to the same body part. Importantly, this effect is accompanied by neurophysiological effects in beta band oscillations. The attenuated power suppression around the time of movement, reflecting decreased cortical excitability, seems to result from motor simulation during action-related language processing. This is in line with embodied cognition theories. Copyright © 2015. Published by Elsevier Inc.

Application of Fast Dynamic Allan Variance for the Characterization of FOGs-Based Measurement While Drilling.

PubMed

Wang, Lu; Zhang, Chunxi; Gao, Shuang; Wang, Tao; Lin, Tie; Li, Xianmu

2016-12-07

The stability of a fiber optic gyroscope (FOG) in measurement while drilling (MWD) could vary with time because of changing temperature, high vibration, and sudden power failure. The dynamic Allan variance (DAVAR) is a sliding version of the Allan variance. It is a practical tool that could represent the non-stationary behavior of the gyroscope signal. Since the normal DAVAR takes too long to deal with long time series, a fast DAVAR algorithm has been developed to accelerate the computation speed. However, both the normal DAVAR algorithm and the fast algorithm become invalid for discontinuous time series. What is worse, the FOG-based MWD underground often keeps working for several days; the gyro data collected aboveground is not only very time-consuming, but also sometimes discontinuous in the timeline. In this article, on the basis of the fast algorithm for DAVAR, we make a further advance in the fast algorithm (improved fast DAVAR) to extend the fast DAVAR to discontinuous time series. The improved fast DAVAR and the normal DAVAR are used to responsively characterize two sets of simulation data. The simulation results show that when the length of the time series is short, the improved fast DAVAR saves 78.93% of calculation time. When the length of the time series is long ( 6 × 10 5 samples), the improved fast DAVAR reduces calculation time by 97.09%. Another set of simulation data with missing data is characterized by the improved fast DAVAR. Its simulation results prove that the improved fast DAVAR could successfully deal with discontinuous data. In the end, a vibration experiment with FOGs-based MWD has been implemented to validate the good performance of the improved fast DAVAR. The results of the experience testify that the improved fast DAVAR not only shortens computation time, but could also analyze discontinuous time series.

Application of Fast Dynamic Allan Variance for the Characterization of FOGs-Based Measurement While Drilling

PubMed Central

Wang, Lu; Zhang, Chunxi; Gao, Shuang; Wang, Tao; Lin, Tie; Li, Xianmu

2016-01-01

The stability of a fiber optic gyroscope (FOG) in measurement while drilling (MWD) could vary with time because of changing temperature, high vibration, and sudden power failure. The dynamic Allan variance (DAVAR) is a sliding version of the Allan variance. It is a practical tool that could represent the non-stationary behavior of the gyroscope signal. Since the normal DAVAR takes too long to deal with long time series, a fast DAVAR algorithm has been developed to accelerate the computation speed. However, both the normal DAVAR algorithm and the fast algorithm become invalid for discontinuous time series. What is worse, the FOG-based MWD underground often keeps working for several days; the gyro data collected aboveground is not only very time-consuming, but also sometimes discontinuous in the timeline. In this article, on the basis of the fast algorithm for DAVAR, we make a further advance in the fast algorithm (improved fast DAVAR) to extend the fast DAVAR to discontinuous time series. The improved fast DAVAR and the normal DAVAR are used to responsively characterize two sets of simulation data. The simulation results show that when the length of the time series is short, the improved fast DAVAR saves 78.93% of calculation time. When the length of the time series is long (6×105 samples), the improved fast DAVAR reduces calculation time by 97.09%. Another set of simulation data with missing data is characterized by the improved fast DAVAR. Its simulation results prove that the improved fast DAVAR could successfully deal with discontinuous data. In the end, a vibration experiment with FOGs-based MWD has been implemented to validate the good performance of the improved fast DAVAR. The results of the experience testify that the improved fast DAVAR not only shortens computation time, but could also analyze discontinuous time series. PMID:27941600

An enhanced Ada run-time system for real-time embedded processors

NASA Technical Reports Server (NTRS)

Sims, J. T.

1991-01-01

An enhanced Ada run-time system has been developed to support real-time embedded processor applications. The primary focus of this development effort has been on the tasking system and the memory management facilities of the run-time system. The tasking system has been extended to support efficient and precise periodic task execution as required for control applications. Event-driven task execution providing a means of task-asynchronous control and communication among Ada tasks is supported in this system. Inter-task control is even provided among tasks distributed on separate physical processors. The memory management system has been enhanced to provide object allocation and protected access support for memory shared between disjoint processors, each of which is executing a distinct Ada program.

Spaceborne computer executive routine functional design specification. Volume 2: Computer executive design for space station/base

NASA Technical Reports Server (NTRS)

Kennedy, J. R.; Fitzpatrick, W. S.

1971-01-01

The computer executive functional system design concepts derived from study of the Space Station/Base are presented. Information Management System hardware configuration as directly influencing the executive design is reviewed. The hardware configuration and generic executive design requirements are considered in detail in a previous report (System Configuration and Executive Requirements Specifications for Reusable Shuttle and Space Station/Base, 9/25/70). This report defines basic system primitives and delineates processes and process control. Supervisor states are considered for describing basic multiprogramming and multiprocessing systems. A high-level computer executive including control of scheduling, allocation of resources, system interactions, and real-time supervisory functions is defined. The description is oriented to provide a baseline for a functional simulation of the computer executive system.

Acute effects of moderate aerobic exercise on specific aspects of executive function in different age and fitness groups: A meta-analysis.

PubMed

Ludyga, Sebastian; Gerber, Markus; Brand, Serge; Holsboer-Trachsler, Edith; Pühse, Uwe

2016-11-01

Whereas a wealth of studies have investigated acute effects of moderate aerobic exercise on executive function, the roles of age, fitness, and the component of executive function in this relationship still remain unclear. Therefore, the present meta-analysis investigates exercise-induced benefits on specific aspects of executive function in different age and aerobic fitness subgroups. Based on data from 40 experimental studies, a small effect of aerobic exercise on time-dependent measures (g = .35) and accuracy (g = .22) in executive function tasks was confirmed. The results further suggest that preadolescent children (g = .54) and older adults (g = .67) compared to other age groups benefit more from aerobic exercise when reaction time is considered as dependent variable. In contrast to age, aerobic fitness and the executive function component had no influence on the obtained effect sizes. Consequently, high aerobic fitness is no prerequisite for temporary improvements of the executive control system, and low- as well as high-fit individuals seem to benefit from exercise in a similar way. However, a higher sensitivity of executive function to acute aerobic exercise was found in individuals undergoing developmental changes. Therefore, preadolescent children and older adults in particular might strategically use a single aerobic exercise session to prepare for a situation demanding high executive control. © 2016 Society for Psychophysiological Research.

Two Approaches to Estimating the Effect of Parenting on the Development of Executive Function in Early Childhood

PubMed Central

Blair, Clancy; Raver, C. Cybele; Berry, Daniel J.

2015-01-01

In the current article, we contrast 2 analytical approaches to estimate the relation of parenting to executive function development in a sample of 1,292 children assessed longitudinally between the ages of 36 and 60 months of age. Children were administered a newly developed and validated battery of 6 executive function tasks tapping inhibitory control, working memory, and attention shifting. Residualized change analysis indicated that higher quality parenting as indicated by higher scores on widely used measures of parenting at both earlier and later time points predicted more positive gain in executive function at 60 months. Latent change score models in which parenting and executive function over time were held to standards of longitudinal measurement invariance provided additional evidence of the association between change in parenting quality and change in executive function. In these models, cross-lagged paths indicated that in addition to parenting predicting change in executive function, executive function bidirectionally predicted change in parenting quality. Results were robust with the addition of covariates, including child sex, race, maternal education, and household income-to-need. Strengths and drawbacks of the 2 analytic approaches are discussed, and the findings are considered in light of emerging methodological innovations for testing the extent to which executive function is malleable and open to the influence of experience. PMID:23834294

Dynamic Reorganization of the Cytoskeleton during Apoptosis: The Two Coffins Hypothesis.

PubMed

Povea-Cabello, Suleva; Oropesa-Ávila, Manuel; de la Cruz-Ojeda, Patricia; Villanueva-Paz, Marina; de la Mata, Mario; Suárez-Rivero, Juan Miguel; Álvarez-Córdoba, Mónica; Villalón-García, Irene; Cotán, David; Ybot-González, Patricia; Sánchez-Alcázar, José A

2017-11-11

During apoptosis, cells undergo characteristic morphological changes in which the cytoskeleton plays an active role. The cytoskeleton rearrangements have been mainly attributed to actinomyosin ring contraction, while microtubule and intermediate filaments are depolymerized at early stages of apoptosis. However, recent results have shown that microtubules are reorganized during the execution phase of apoptosis forming an apoptotic microtubule network (AMN). Evidence suggests that AMN is required to maintain plasma membrane integrity and cell morphology during the execution phase of apoptosis. The new "two coffins" hypothesis proposes that both AMN and apoptotic cells can adopt two morphological patterns, round or irregular, which result from different cytoskeleton kinetic reorganization during the execution phase of apoptosis induced by genotoxic agents. In addition, round and irregular-shaped apoptosis showed different biological properties with respect to AMN maintenance, plasma membrane integrity and phagocyte responses. These findings suggest that knowing the type of apoptosis may be important to predict how fast apoptotic cells undergo secondary necrosis and the subsequent immune response. From a pathological point of view, round-shaped apoptosis can be seen as a physiological and controlled type of apoptosis, while irregular-shaped apoptosis can be considered as a pathological type of cell death closer to necrosis.

Dynamic Reorganization of the Cytoskeleton during Apoptosis: The Two Coffins Hypothesis

PubMed Central

Povea-Cabello, Suleva; Oropesa-Ávila, Manuel; de la Cruz-Ojeda, Patricia; Villanueva-Paz, Marina; de la Mata, Mario; Álvarez-Córdoba, Mónica; Villalón-García, Irene; Cotán, David; Ybot-González, Patricia

2017-01-01

During apoptosis, cells undergo characteristic morphological changes in which the cytoskeleton plays an active role. The cytoskeleton rearrangements have been mainly attributed to actinomyosin ring contraction, while microtubule and intermediate filaments are depolymerized at early stages of apoptosis. However, recent results have shown that microtubules are reorganized during the execution phase of apoptosis forming an apoptotic microtubule network (AMN). Evidence suggests that AMN is required to maintain plasma membrane integrity and cell morphology during the execution phase of apoptosis. The new “two coffins” hypothesis proposes that both AMN and apoptotic cells can adopt two morphological patterns, round or irregular, which result from different cytoskeleton kinetic reorganization during the execution phase of apoptosis induced by genotoxic agents. In addition, round and irregular-shaped apoptosis showed different biological properties with respect to AMN maintenance, plasma membrane integrity and phagocyte responses. These findings suggest that knowing the type of apoptosis may be important to predict how fast apoptotic cells undergo secondary necrosis and the subsequent immune response. From a pathological point of view, round-shaped apoptosis can be seen as a physiological and controlled type of apoptosis, while irregular-shaped apoptosis can be considered as a pathological type of cell death closer to necrosis. PMID:29137119

Branch-Based Centralized Data Collection for Smart Grids Using Wireless Sensor Networks

PubMed Central

Kim, Kwangsoo; Jin, Seong-il

2015-01-01

A smart grid is one of the most important applications in smart cities. In a smart grid, a smart meter acts as a sensor node in a sensor network, and a central device collects power usage from every smart meter. This paper focuses on a centralized data collection problem of how to collect every power usage from every meter without collisions in an environment in which the time synchronization among smart meters is not guaranteed. To solve the problem, we divide a tree that a sensor network constructs into several branches. A conflict-free query schedule is generated based on the branches. Each power usage is collected according to the schedule. The proposed method has important features: shortening query processing time and avoiding collisions between a query and query responses. We evaluate this method using the ns-2 simulator. The experimental results show that this method can achieve both collision avoidance and fast query processing at the same time. The success rate of data collection at a sink node executing this method is 100%. Its running time is about 35 percent faster than that of the round-robin method, and its memory size is reduced to about 10% of that of the depth-first search method. PMID:26007734

QuickProbs—A Fast Multiple Sequence Alignment Algorithm Designed for Graphics Processors

PubMed Central

Gudyś, Adam; Deorowicz, Sebastian

2014-01-01

Multiple sequence alignment is a crucial task in a number of biological analyses like secondary structure prediction, domain searching, phylogeny, etc. MSAProbs is currently the most accurate alignment algorithm, but its effectiveness is obtained at the expense of computational time. In the paper we present QuickProbs, the variant of MSAProbs customised for graphics processors. We selected the two most time consuming stages of MSAProbs to be redesigned for GPU execution: the posterior matrices calculation and the consistency transformation. Experiments on three popular benchmarks (BAliBASE, PREFAB, OXBench-X) on quad-core PC equipped with high-end graphics card show QuickProbs to be 5.7 to 9.7 times faster than original CPU-parallel MSAProbs. Additional tests performed on several protein families from Pfam database give overall speed-up of 6.7. Compared to other algorithms like MAFFT, MUSCLE, or ClustalW, QuickProbs proved to be much more accurate at similar speed. Additionally we introduce a tuned variant of QuickProbs which is significantly more accurate on sets of distantly related sequences than MSAProbs without exceeding its computation time. The GPU part of QuickProbs was implemented in OpenCL, thus the package is suitable for graphics processors produced by all major vendors. PMID:24586435

Branch-based centralized data collection for smart grids using wireless sensor networks.

PubMed

Kim, Kwangsoo; Jin, Seong-il

2015-05-21

A smart grid is one of the most important applications in smart cities. In a smart grid, a smart meter acts as a sensor node in a sensor network, and a central device collects power usage from every smart meter. This paper focuses on a centralized data collection problem of how to collect every power usage from every meter without collisions in an environment in which the time synchronization among smart meters is not guaranteed. To solve the problem, we divide a tree that a sensor network constructs into several branches. A conflict-free query schedule is generated based on the branches. Each power usage is collected according to the schedule. The proposed method has important features: shortening query processing time and avoiding collisions between a query and query responses. We evaluate this method using the ns-2 simulator. The experimental results show that this method can achieve both collision avoidance and fast query processing at the same time. The success rate of data collection at a sink node executing this method is 100%. Its running time is about 35 percent faster than that of the round-robin method, and its memory size is reduced to about 10% of that of the depth-first search method.

Real-time Java for flight applications: an update

NASA Technical Reports Server (NTRS)

Dvorak, D.

2003-01-01

The RTSJ is a specification for supporting real-time execution in the Java programming language. The specification has been shaped by several guiding principles, particularly: predictable execution as the first priority in all tradeoffs, no syntactic extensions to Java, and backward compatibility.

Literacy in the Workplace: The Executive Perspective. A Qualitative Research Study.

ERIC Educational Resources Information Center

Omega Group, Inc., Haverford, PA.

Twenty-eight in-depth interviews were conducted with top executives in Philadelphia to discover issues and concerns about committing organizational resources over time to workplace literacy programs. Participants represented major organizations and institutions, both manufacturing and service. The executives reported that the manifestations of…

Developing high-level change and innovation agents: competencies and challenges for executive leadership.

PubMed

Malloch, Kathy; Melnyk, Bernadette Mazurek

2013-01-01

The work of health care reform and revolution requires leadership competencies that integrate the digital realities of time, space, and media. Leadership skills and behaviors of command, control, and directing from predigital times are no longer effective, given the impacts of the digital changes. Developing leadership competence in evidence-driven processes, facilitation, collaborative teamwork, and instilling a sense of urgency is the work of today's executive leaders. Ten competencies necessary for contemporary executive leadership are presented in this article.

Levinson's Dream Theory and Its Relevance in an Academic Executive Mentoring Program: An Exploratory Study of Executive Mentors' Practice and Individuation

ERIC Educational Resources Information Center

Scherer, Douglas Martin

2010-01-01

The purpose of this study was to explore the relevance that executive mentors' Dream journeys had for their mentoring practices. Dream journeys are the visions of where young adults see themselves in the future, and how they integrate themselves into the adult world over time. It was anticipated that a better understanding of executive mentors'…

Functionality of disintegrants and their mixtures in enabling fast disintegration of tablets by a quality by design approach.

PubMed

Desai, Parind Mahendrakumar; Er, Patrick Xuan Hua; Liew, Celine Valeria; Heng, Paul Wan Sia

2014-10-01

Investigation of the effect of disintegrants on the disintegration time and hardness of rapidly disintegrating tablets (RDTs) was carried out using a quality by design (QbD) paradigm. Ascorbic acid, aspirin, and ibuprofen, which have different water solubilities, were chosen as the drug models. Disintegration time and hardness of RDTs were determined and modeled by executing combined optimal design. The generated models were validated and used for further analysis. Sodium starch glycolate, croscarmellose sodium, and crospovidone were found to lengthen disintegration time when utilized at high concentrations. Sodium starch glycolate and crospovidone worked synergistically in aspirin RDTs to decrease disintegration time. Sodium starch glycolate-crospovidone mixtures, as well as croscarmellose sodium-crospovidone mixtures, also decreased disintegration time in ibuprofen RDTs at high compression pressures as compared to the disintegrants used alone. The use of sodium starch glycolate in RDTs with highly water soluble active ingredients like ascorbic acid slowed disintegration, while microcrystalline cellulose and crospovidone drew water into the tablet rapidly and quickened disintegration. Graphical optimization analysis demonstrated that the RDTs with desired disintegration times and hardness can be formulated with a larger area of design space by combining disintegrants at difference compression pressures. QbD was an efficient and effective paradigm in understanding formulation and process parameters and building quality in to RDT formulated systems.

76 FR 34281 - Self-Regulatory Organizations; The NASDAQ Stock Market LLC; Notice of Filing of Proposed Rule...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-13

...''). The specified time period will commence for an option when a transaction occurs in any series in such... contracts executed among all series during the specified time period that represents an issue percentage... executed among all series during the specified time period that represents an issue percentage equal to the...

AN OPTIMIZED 64X64 POINT TWO-DIMENSIONAL FAST FOURIER TRANSFORM

NASA Technical Reports Server (NTRS)

Miko, J.

1994-01-01

Scientists at Goddard have developed an efficient and powerful program-- An Optimized 64x64 Point Two-Dimensional Fast Fourier Transform-- which combines the performance of real and complex valued one-dimensional Fast Fourier Transforms (FFT's) to execute a two-dimensional FFT and its power spectrum coefficients. These coefficients can be used in many applications, including spectrum analysis, convolution, digital filtering, image processing, and data compression. The program's efficiency results from its technique of expanding all arithmetic operations within one 64-point FFT; its high processing rate results from its operation on a high-speed digital signal processor. For non-real-time analysis, the program requires as input an ASCII data file of 64x64 (4096) real valued data points. As output, this analysis produces an ASCII data file of 64x64 power spectrum coefficients. To generate these coefficients, the program employs a row-column decomposition technique. First, it performs a radix-4 one-dimensional FFT on each row of input, producing complex valued results. Then, it performs a one-dimensional FFT on each column of these results to produce complex valued two-dimensional FFT results. Finally, the program sums the squares of the real and imaginary values to generate the power spectrum coefficients. The program requires a Banshee accelerator board with 128K bytes of memory from Atlanta Signal Processors (404/892-7265) installed on an IBM PC/AT compatible computer (DOS ver. 3.0 or higher) with at least one 16-bit expansion slot. For real-time operation, an ASPI daughter board is also needed. The real-time configuration reads 16-bit integer input data directly into the accelerator board, operating on 64x64 point frames of data. The program's memory management also allows accumulation of the coefficient results. The real-time processing rate to calculate and accumulate the 64x64 power spectrum output coefficients is less than 17.0 mSec. Documentation is included in the price of the program. Source code is written in C, 8086 Assembly, and Texas Instruments TMS320C30 Assembly Languages. This program is available on a 5.25 inch 360K MS-DOS format diskette. IBM and IBM PC are registered trademarks of International Business Machines. MS-DOS is a registered trademark of Microsoft Corporation.

Is capacity for pleasure associated with executive career success?

PubMed

Clark, D C; Morrison, D E; Fawcett, J

1984-01-01

Executives with a low capacity for pleasure were examined to determine if they evidence less occupational and social success than those with normal or high capacity. Data on pleasure capacity and depressive symptoms were collected from 88 senior executive officers, and scores were compared with independent ratings of career success. The 11% of executives with serious work-related or personal problems showed significantly higher pleasure scores than the rest. It is hypothesized that the relatively high pleasure scores of the least successful executives reflect a defensive process of denial or reaction formation rather than an excessively joyful personality trait. A longitudinal study of executives is proposed to clarify whether the high pleasure capacity scores of the least successful executives change situationally over time.

This Working Life.

ERIC Educational Resources Information Center

Boothe, James W.; And Others

1994-01-01

Recent "Executive Educator" survey of 900 out of 6,200 randomly selected school executives found high school principals had the longest work week; 95.3% reported working over 50 hours weekly. Fully 78% of school executives are devoting more time to educational improvement changes. Despite stressors and salary complaints, most are content with…

78 FR 22225 - Meeting: African Development Foundation, Board of Directors Executive Session Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-15

...;and investigations, committee meetings, agency decisions and rulings, #0;delegations of authority... Executive Session Meeting Meeting: African Development Foundation, Board of Directors Executive Session Meeting Time: Tuesday, April 23, 2013 11:15 a.m. to 2:15 p.m. Place: 1400 Eye Street NW., Suite 1000...

Serum 25-hydroxyvitamin D is associated with cognitive executive function in Dutch prefrail and frail elderly: a cross-sectional study exploring the associations of 25-hydroxyvitamin D with glucose metabolism, cognitive performance and depression.

PubMed

Brouwer-Brolsma, Elske M; van de Rest, Ondine; Tieland, Michael; van der Zwaluw, Nikita L; Steegenga, Wilma T; Adam, Jos J; van Loon, Luc J C; Feskens, Edith J M; de Groot, Lisette C P G M

2013-11-01

The primary objective was to explore the possible association of serum 25-hydroxyvitamin D (25[OH]D) and vitamin D intake with markers of glucose metabolism, depression, and cognitive performance. In addition, we examined to what extent the associations between vitamin D and cognitive performance were modified or mediated by fasting plasma glucose (FPG) levels. Cross-sectional study using data of 127 frail or prefrail Dutch elderly, aged 65 years or older. Frailty was defined according to the criteria of Fried and colleagues. A participant was classified prefrail when 1 to 2 criteria were met; frailty was classified as the presence of 3 or more criteria. Associations of 25(OH)D and vitamin D intake with markers of glucose metabolism and domain-specific cognitive performance were examined by multivariable regression analyses. The possible association of vitamin D with depression and global cognitive performance was explored by Poisson regression. No associations were observed for 25(OH)D with FPG, fasting plasma insulin (FPI), Homeostasis Model Assessment-estimated Insulin Resistance (HOMA-IR), or depression. In contrast, serum 25(OH)D was positively associated with executive functioning (β 0.007, P = .01) and tended to be associated with information-processing speed (β 0.006, P = .06). FPG did not modify or mediate these associations. Vitamin D intake was not associated with cognitive performance, glucose metabolism, or depression. This cross-sectional study suggests an association of serum 25(OH)D with domain-specific cognitive performance, in particular executive functioning and possibly information-processing speed, but not with FPG, FPI, HOMA-IR, or depression. Whether these associations are causal is yet to be demonstrated. Copyright © 2013 American Medical Directors Association, Inc. Published by Elsevier Inc. All rights reserved.

Effects of a Six-Week Strength Training Programme on Change of Direction Performance in Youth Team Sport Athletes

PubMed Central

Bourgeois, Frank A.; Gamble, Paul; Gill, Nic D.; McGuigan, Mike R.

2017-01-01

This study investigated the effects of eccentric phase-emphasis strength training (EPE) on unilateral strength and performance in 180- and 45-degree change of direction (COD) tasks in rugby union players. A 12-week cross-over design was used to compare the efficacy of resistance training executed with 3 s eccentric duration (EPE, n = 12) against conventional strength training, with no constraints on tempo (CON, n = 6). Players in each condition were categorised as ‘fast’ (FAST) or ‘slow’ (SLOW) using median trial times from baseline testing. Players recorded greater isometric strength improvements following EPE (ES = −0.54 to 1.80). Whilst these changes were not immediate, players improved in strength following cessation. Improvements in 180-degree COD performance was recorded at all test-points following EPE (ES = −1.32 to −0.15). Improvements in 45-degree COD performance were apparent for FAST following CON (ES = −0.96 to 0.10), but CON was deleterious for SLOW (ES = −0.60 to 1.53). Eccentric phase-emphasis strength training shows potential for sustained strength enhancement. Positive performance changes in COD tasks were category- and condition-specific. The data indicate the greatest improvement occurred at nine weeks following resistance training in these players. Performance benefits may also be specific to COD task, player category, and relative to emphasis on eccentric phase activity. PMID:29910443

Effects of stop-signal probability in the stop-signal paradigm: the N2/P3 complex further validated.

PubMed

Ramautar, J R; Kok, A; Ridderinkhof, K R

2004-11-01

The aim of this study was to examine the effects of frequency of occurrence of stop signals in the stop-signal paradigm. Presenting stop signals less frequently resulted in faster reaction times to the go stimulus and a lower probability of inhibition. Also, go stimuli elicited larger and somewhat earlier P3 responses when stop signals occurred less frequently. Since the amplitude effect was more pronounced on trials when go signals were followed by fast than slow reactions, it probably reflected a stronger set to produce fast responses. N2 and P3 components to stop signals were observed to be larger and of longer latency when stop signals occurred less frequently. The amplitude enhancement of these N2 and P3 components were more pronounced for unsuccessful than for successful stop-signal trials. Moreover, the successfully inhibited stop trials elicited a frontocentral P3 whereas unsuccessfully inhibited stop trials elicited a more posterior P3 that resembled the classical P3b. P3 amplitude in the unsuccessfully inhibited condition also differed between waveforms synchronized with the stop signal and waveforms synchronized with response onset whereas N2 amplitude did not. Taken together these findings suggest that N2 reflected a greater significance of failed inhibitions after low probability stop signals while P3 reflected continued processing of the erroneous response after response execution.

PCM-Based Durable Write Cache for Fast Disk I/O

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

Liu, Zhuo; Wang, Bin; Carpenter, Patrick

2012-01-01

Flash based solid-state devices (FSSDs) have been adopted within the memory hierarchy to improve the performance of hard disk drive (HDD) based storage system. However, with the fast development of storage-class memories, new storage technologies with better performance and higher write endurance than FSSDs are emerging, e.g., phase-change memory (PCM). Understanding how to leverage these state-of-the-art storage technologies for modern computing systems is important to solve challenging data intensive computing problems. In this paper, we propose to leverage PCM for a hybrid PCM-HDD storage architecture. We identify the limitations of traditional LRU caching algorithms for PCM-based caches, and develop amore » novel hash-based write caching scheme called HALO to improve random write performance of hard disks. To address the limited durability of PCM devices and solve the degraded spatial locality in traditional wear-leveling techniques, we further propose novel PCM management algorithms that provide effective wear-leveling while maximizing access parallelism. We have evaluated this PCM-based hybrid storage architecture using applications with a diverse set of I/O access patterns. Our experimental results demonstrate that the HALO caching scheme leads to an average reduction of 36.8% in execution time compared to the LRU caching scheme, and that the SFC wear leveling extends the lifetime of PCM by a factor of 21.6.« less

The fast azimuthal integration Python library: pyFAI.

PubMed

Ashiotis, Giannis; Deschildre, Aurore; Nawaz, Zubair; Wright, Jonathan P; Karkoulis, Dimitrios; Picca, Frédéric Emmanuel; Kieffer, Jérôme

2015-04-01

pyFAI is an open-source software package designed to perform azimuthal integration and, correspondingly, two-dimensional regrouping on area-detector frames for small- and wide-angle X-ray scattering experiments. It is written in Python (with binary submodules for improved performance), a language widely accepted and used by the scientific community today, which enables users to easily incorporate the pyFAI library into their processing pipeline. This article focuses on recent work, especially the ease of calibration, its accuracy and the execution speed for integration.

Revising Army National Guard Officer Retention Boards

DTIC Science & Technology

2006-02-06

performance in the corporate world by a multi-national U. S . based corporation is McDonalds . This well known company, founded in 1955, was the... franchising ) to grow McDonalds into the premier fast food giant it has become. McDonald’s recently set a mandatory retirement age for its executives...Retention Boards 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) Keith Mabry 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK

The ADAMS interactive interpreter

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

Rietscha, E.R.

1990-12-17

The ADAMS (Advanced DAta Management System) project is exploring next generation database technology. Database management does not follow the usual programming paradigm. Instead, the database dictionary provides an additional name space environment that should be interactively created and tested before writing application code. This document describes the implementation and operation of the ADAMS Interpreter, an interactive interface to the ADAMS data dictionary and runtime system. The Interpreter executes individual statements of the ADAMS Interface Language, providing a fast, interactive mechanism to define and access persistent databases. 5 refs.

Floating-point function generation routines for 16-bit microcomputers

NASA Technical Reports Server (NTRS)

Mackin, M. A.; Soeder, J. F.

1984-01-01

Several computer subroutines have been developed that interpolate three types of nonanalytic functions: univariate, bivariate, and map. The routines use data in floating-point form. However, because they are written for use on a 16-bit Intel 8086 system with an 8087 mathematical coprocessor, they execute as fast as routines using data in scaled integer form. Although all of the routines are written in assembly language, they have been implemented in a modular fashion so as to facilitate their use with high-level languages.

Working Out the Tensions: Fast Track Authority as a Study in Executive/Congressional Cooperation

DTIC Science & Technology

1995-01-01

Le,olsiatl\\e purview, but Congress recognizes the I Execuhve IS the branch able to negohate mternatlonal deals cutting tariffs or opemng markets ...fought Canada over Its durum wheat esports to pick up the votes of wheat state senators angry oter nsrng sales of Canadian wheat and a findmg by an...NAFTA or some other free trade arrangement and to open East Asian markets Hoxsever, controversies m the mock mark-ups of the drafi Uruguay Round

Model-based Executive Control through Reactive Planning for Autonomous Rovers

NASA Technical Reports Server (NTRS)

Finzi, Alberto; Ingrand, Felix; Muscettola, Nicola

2004-01-01

This paper reports on the design and implementation of a real-time executive for a mobile rover that uses a model-based, declarative approach. The control system is based on the Intelligent Distributed Execution Architecture (IDEA), an approach to planning and execution that provides a unified representational and computational framework for an autonomous agent. The basic hypothesis of IDEA is that a large control system can be structured as a collection of interacting agents, each with the same fundamental structure. We show that planning and real-time response are compatible if the executive minimizes the size of the planning problem. We detail the implementation of this approach on an exploration rover (Gromit an RWI ATRV Junior at NASA Ames) presenting different IDEA controllers of the same domain and comparing them with more classical approaches. We demonstrate that the approach is scalable to complex coordination of functional modules needed for autonomous navigation and exploration.

Method and apparatus for fault tolerance

NASA Technical Reports Server (NTRS)

Masson, Gerald M. (Inventor); Sullivan, Gregory F. (Inventor)

1993-01-01

A method and apparatus for achieving fault tolerance in a computer system having at least a first central processing unit and a second central processing unit. The method comprises the steps of first executing a first algorithm in the first central processing unit on input which produces a first output as well as a certification trail. Next, executing a second algorithm in the second central processing unit on the input and on at least a portion of the certification trail which produces a second output. The second algorithm has a faster execution time than the first algorithm for a given input. Then, comparing the first and second outputs such that an error result is produced if the first and second outputs are not the same. The step of executing a first algorithm and the step of executing a second algorithm preferably takes place over essentially the same time period.

Triglycerides are negatively correlated with cognitive function in nondemented aging adults.

PubMed

Parthasarathy, Vishnu; Frazier, Darvis T; Bettcher, Brianne M; Jastrzab, Laura; Chao, Linda; Reed, Bruce; Mungas, Dan; Weiner, Michael; DeCarli, Charles; Chui, Helena; Kramer, Joel H

2017-09-01

Vascular risk factors like hyperlipidemia may adversely affect brain function. We hypothesized that increased serum triglycerides are associated with decreased executive function and memory in nondemented elderly subjects. We also researched possible vascular mediators and white matter microstructure as assessed with diffusion tensor imaging (DTI). Participants were 251 nondemented elderly adults (54% male) with a mean age of 78 (SD = 6.4; range: 62-94) years and a mean education of 15.6 (SD = 2.9; range: 8-23) years. Fasting blood samples were used to detect serum triglyceride and low-density lipoprotein (LDL) levels along with ApoE4 status. DTI was used to determine whole brain fractional anisotropy (FA). Composite executive and memory scores were derived from item response theory. Clinical Dementia Rating (CDR) scores provided informant-based measures of daily functioning. Triglyceride levels were inversely correlated with executive function, but there was no relationship with memory. Controlling for age, gender, and education did not affect this correlation. This relationship persisted after controlling for vascular risk factors like LDL, total cholesterol, CDR and ApoE4 status. Lastly, adding whole-brain FA to the model did not affect the correlation between triglycerides and executive function. Triglyceride levels are inversely correlated with executive function in nondemented elderly adults after controlling for age, education, gender, total cholesterol, LDL, ApoE4 status, CDR, and white-matter microstructure. The fact that the effect of triglycerides on cognition was not clearly mediated by vascular risks or cerebrovascular injury raises questions about widely held assumptions of how triglycerides might impact cognition function. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Fluid Intelligence as a Mediator of the Relationship between Executive Control and Balanced Time Perspective.

PubMed

Zajenkowski, Marcin; Stolarski, Maciej; Witowska, Joanna; Maciantowicz, Oliwia; Łowicki, Paweł

2016-01-01

This study examined the cognitive foundations of the balanced time perspective (BTP) proposed by Zimbardo and Boyd (1999). Although BTP is defined as the mental ability to switch effectively between different temporal perspectives, its connection with cognitive functioning has not yet been established. We addressed this by exploring the relationships between time perspectives and both fluid intelligence (measured with Raven's and Cattell's tests) and executive control (Go/No-go and anti-saccade tasks). An investigation conducted among Polish adults ( N = 233) revealed that more balanced TP profile was associated with higher fluid intelligence, and higher executive control. Moreover, we found that the relationship between executive control and BTP was completely mediated by fluid intelligence with the effect size (the ratio of the indirect effect to the total effect) of 0.75, which suggests that cognitive abilities play an important role in adoption of temporal balance. The findings have relevance to time perspective theory as they provide valuable insight into the mechanisms involved in assigning human experience to certain time frames.

RPYFMM: Parallel adaptive fast multipole method for Rotne-Prager-Yamakawa tensor in biomolecular hydrodynamics simulations

NASA Astrophysics Data System (ADS)

Guan, W.; Cheng, X.; Huang, J.; Huber, G.; Li, W.; McCammon, J. A.; Zhang, B.

2018-06-01

RPYFMM is a software package for the efficient evaluation of the potential field governed by the Rotne-Prager-Yamakawa (RPY) tensor interactions in biomolecular hydrodynamics simulations. In our algorithm, the RPY tensor is decomposed as a linear combination of four Laplace interactions, each of which is evaluated using the adaptive fast multipole method (FMM) (Greengard and Rokhlin, 1997) where the exponential expansions are applied to diagonalize the multipole-to-local translation operators. RPYFMM offers a unified execution on both shared and distributed memory computers by leveraging the DASHMM library (DeBuhr et al., 2016, 2018). Preliminary numerical results show that the interactions for a molecular system of 15 million particles (beads) can be computed within one second on a Cray XC30 cluster using 12,288 cores, while achieving approximately 54% strong-scaling efficiency.

Staying on Task: Age-Related Changes in the Relationship Between Executive Functioning and Response Time Consistency.

PubMed

Vasquez, Brandon P; Binns, Malcolm A; Anderson, Nicole D

2016-03-01

Little is known about the relationship of executive functioning with age-related increases in response time (RT) distribution indices (intraindividual standard deviation [ISD], and ex-Gaussian parameters mu, sigma, tau). The goals of this study were to (a) replicate findings of age-related changes in response time distribution indices during an engaging touch-screen RT task and (b) investigate age-related changes in the relationship between executive functioning and RT distribution indices. Healthy adults (24 young [aged 18-30], 24 young-old [aged 65-74], and 24 old-old [aged 75-85]) completed a touch-screen attention task and a battery of neuropsychological tests. The relationships between RT performance and executive functions were examined with structural equation modeling (SEM). ISD, mu, and tau, but not sigma, increased with age. SEM revealed tau as the most salient RT index associated with neuropsychological measures of executive functioning. Further analysis demonstrated that correlations between tau and a weighted executive function composite were significant only in the old-old group. Our results replicate findings of greater RT inconsistency in older adults and reveal that executive functioning is related to tau in adults aged 75-85. These results support literature identifying tau as a marker of cognitive control, which deteriorates in old age. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The AMchip04 and the processing unit prototype for the FastTracker

NASA Astrophysics Data System (ADS)

Andreani, A.; Annovi, A.; Beretta, M.; Bogdan, M.; Citterio, M.; Alberti, F.; Giannetti, P.; Lanza, A.; Magalotti, D.; Piendibene, M.; Shochet, M.; Stabile, A.; Tang, J.; Tompkins, L.; Volpi, G.

2012-08-01

Modern experiments search for extremely rare processes hidden in much larger background levels. As the experiment`s complexity, the accelerator backgrounds and luminosity increase we need increasingly complex and exclusive event selection. We present the first prototype of a new Processing Unit (PU), the core of the FastTracker processor (FTK). FTK is a real time tracking device for the ATLAS experiment`s trigger upgrade. The computing power of the PU is such that a few hundred of them will be able to reconstruct all the tracks with transverse momentum above 1 GeV/c in ATLAS events up to Phase II instantaneous luminosities (3 × 1034 cm-2 s-1) with an event input rate of 100 kHz and a latency below a hundred microseconds. The PU provides massive computing power to minimize the online execution time of complex tracking algorithms. The time consuming pattern recognition problem, generally referred to as the ``combinatorial challenge'', is solved by the Associative Memory (AM) technology exploiting parallelism to the maximum extent; it compares the event to all pre-calculated ``expectations'' or ``patterns'' (pattern matching) simultaneously, looking for candidate tracks called ``roads''. This approach reduces to a linear behavior the typical exponential complexity of the CPU based algorithms. Pattern recognition is completed by the time data are loaded into the AM devices. We report on the design of the first Processing Unit prototypes. The design had to address the most challenging aspects of this technology: a huge number of detector clusters (``hits'') must be distributed at high rate with very large fan-out to all patterns (10 Million patterns will be located on 128 chips placed on a single board) and a huge number of roads must be collected and sent back to the FTK post-pattern-recognition functions. A network of high speed serial links is used to solve the data distribution problem.

Mouth rinsing with a carbohydrate solution attenuates exercise-induced decline in executive function.

PubMed

Konishi, Kana; Kimura, Tetsuya; Yuhaku, Atsushi; Kurihara, Toshiyuki; Fujimoto, Masahiro; Hamaoka, Takafumi; Sanada, Kiyoshi

2017-01-01

A decline in executive function could have a negative influence on the control of actions in dynamic situations, such as sports activities. Mouth rinsing with a carbohydrate solution could serve as an effective treatment for preserving the executive function in exercise. The purpose of this study was to examine the effects of mouth rinsing with a carbohydrate solution on executive function after sustained moderately high-intensity exercise. Eight young healthy participants completed 65 min of running at 75% V̇O 2 max with two mouth-rinsing conditions: with a carbohydrate solution (CHO) or with water (CON). Executive function was assessed before and after exercise by using the incongruent task of the Stroop Color and Word Test. The levels of blood glucose; and plasma adrenocorticotropic hormone (ACTH), epinephrine, and norepinephrine (NE) were evaluated. A two-way repeated-measures ANOVA, with condition (CHO and CON) and time (pre-exercise and post-exercise) as factors, was used to examine the main and interaction effects on the outcome measures. The reaction time in the incongruent condition of the Stroop test significantly increased after exercise in CON (pre-exercise 529 ± 45 ms vs. post-exercise 547 ± 60 ms, P  = 0.029) but not in CHO (pre-exercise 531 ± 54 ms vs. post-exercise 522 ± 80 ms), which resulted in a significant interaction (condition × time) on the reaction time ( P  = 0.028). The increased reaction time in CON indicates a decline in the executive function, which was attenuated in CHO. Increases in plasma epinephrine and NE levels demonstrated a trend toward attenuation accompanying CHO ( P  < 0.085), which appeared to be associated with the preservation of executive function. The blood glucose concentration showed neither significant interactions nor main effects of condition. These findings indicate that mouth rinsing with a carbohydrate solution attenuated the decline in executive function induced by sustained moderately high-intensity exercise, and that such attenuation seems to be unrelated to carbohydrate metabolic pathway but rather attributed, in part, to the inhibition of the excessive release of stress hormones.

The SNAPSHOT study protocol: SNAcking, Physical activity, Self-regulation, and Heart rate Over Time.

PubMed

McMinn, David; Allan, Julia L

2014-09-26

The cognitive processes responsible for effortful behavioural regulation are known as the executive functions, and are implicated in several factors associated with behaviour control, including focussing on tasks, resisting temptations, planning future actions, and inhibiting prepotent responses. Similar to muscles, the executive functions become fatigued following intensive use (e.g. stressful situations, when tired or busy, and when regulating behaviour such as quitting smoking). Therefore, an individual may be more susceptible to engaging in unhealthy behaviours when their executive functions are depleted. In the present study we investigate associations between the executive functions, snack food consumption, and sedentary behaviour in real time. We hypothesise that individuals may be more susceptible to unhealthy snacking and sedentary behaviours during periods when their executive functions are depleted. We test this hypothesis using real-time objective within-person measurements. A sample of approximately 50 Scottish adults from varied socio-economic, working, and cultural backgrounds will participate in the three phases of the SNAcking, Physical activity, Self-regulation, and Heart rate Over Time (SNAPSHOT) study. Phase one will require participants to complete home-based questionnaires concerned with diet, eating behaviour, and physical activity (≈1.5 hours to complete). Phase two will constitute a 2-3 hour psychological laboratory testing session during which trait-level executive function, general intelligence, and diet and physical activity intentions, past behaviour, and automaticity will be measured. The final phase will involve a 7-day ambulatory protocol during which objective repeated assessments of executive function, snacking behaviour, physical activity, mood, heart rate, perceived energy level, current context and location will be measured during participants' daily routines. Multi-level regression analysis, accounting for observations nested within participants, will be used to investigate associations between fluctuations in the executive functions and health behaviours. Data from the SNAPSHOT study will provide ecologically valid information to help better understand the temporal associations between self-regulatory resources (executive functions) and deleterious health behaviours such as snacking and sedentary behaviour. If we can identify particular periods of the day or locations where self-regulatory resources become depleted and produce suboptimal health behaviour, then interventions can be designed and targeted accordingly.

A prospective audit of preprocedural fasting practices on a transplant ward: when fasting becomes starving.

PubMed

Vidot, Helen; Teevan, Kate; Carey, Sharon; Strasser, Simone; Shackel, Nicholas

2016-03-01

To investigate the prevalence and duration of preprocedural medically ordered fasting during a period of hospitalisation in an Australian population of patients with hepatic cirrhosis or following liver transplantation and to identify potential solutions to reduce fasting times. Protein-energy malnutrition is a common finding in patients with hepatic cirrhosis and can impact significantly on survival and quality of life. Protein and energy requirements in patients with cirrhosis are higher than those of healthy individuals. A significant feature of cirrhosis is the induction of starvation metabolism following seven to eight hours of food deprivation. Many investigative and interventional procedures for patients with cirrhosis necessitate a period of fasting to comply with anaesthesia guidelines. An observational study of the fasting episodes for 34 hospitalised patients with hepatic cirrhosis or following liver transplantation. Nutritional status was estimated using subjective global assessment and handgrip strength. The prevalence and duration of fasting practices for diagnostic or investigational procedures were estimated using electronic records and patient notes. Thirty-three patients (97%) were malnourished. Twenty-two patients (65%) were fasted during the observation period. There were 43 occasions of fasting with a median fasting time of 13·5 hours. On 40 occasions fasting times exceeded the maximum six-hour guideline recommended prior to the administration of anaesthesia by the majority of Anaesthesiology Societies. The majority of procedures (77%) requiring fasting occurred after midday. Eating breakfast on the day of the procedure reduced fasting time by 45%. Medically ordered preprocedural fasting times almost always exceed existing guidelines in this nutritionally compromised group. Adherence to fasting guidelines and eating breakfast before the procedure can reduce fasting times significantly and avoid the potential induction of starvation metabolism in this nutritionally at risk group. © 2016 John Wiley & Sons Ltd.

Executive Function, Survival, and Hospitalization in Chronic Obstructive Pulmonary Disease. A Longitudinal Analysis of the National Emphysema Treatment Trial (NETT).

PubMed

Dodd, James W; Novotny, Paul; Sciurba, Frank C; Benzo, Roberto P

2015-10-01

Cognitive dysfunction has been demonstrated in chronic obstructive pulmonary disease (COPD), but studies are limited to cross-sectional analyses or incompletely characterized populations. We examined longitudinal changes in sensitive measures of executive function in a well-characterized population of patients with severe COPD. This study was performed on patients enrolled in the National Emphysema Treatment Trial. To assess executive function, we analyzed trail making (TM) A and B times at enrollment in the trial (2,128 patients), and at 12 (731 patients) and 24 months (593 patients) after enrollment, adjusted for surgery, marriage status, age, education, income, depression, PaO2, PaCO2, and smoking. Associations with survival and hospitalizations were examined using Cox regression and linear regression models. The average age of the patients was 66.4 years, and the average FEV1 was 23.9% predicted. At the time of enrolment, 38% had executive dysfunction. Compared with those who did not, these patients were older, less educated, had higher oxygen use, higher PaCO2, worse quality of life as measured by the St. George's Respiratory Quotient, reduced well-being, and lower social function. There was no significant change over 2 years in TM A or B times after adjustment for covariables. Changes in TM B times were modestly associated with survival, but changes in TM B-A times were not. Changes in TM scores were not associated with frequency of hospitalization. Lung function, PaO2, smoking, survival, and hospitalizations were not significantly different in those with executive dysfunction. In this large population of patients with severe emphysema and heavy cigarette smoking exposure, there was no significant decline over 2 years in cognitive executive function as measured by TM tests. There was no association between executive function impairment and frequency of hospitalization, and there was a possible modest association with survival. It is plausible that cerebrovascular comorbidities explain previously described cognitive pathology in COPD.

A Hybrid Procedural/Deductive Executive for Autonomous Spacecraft

NASA Technical Reports Server (NTRS)

Pell, Barney; Gamble, Edward B.; Gat, Erann; Kessing, Ron; Kurien, James; Millar, William; Nayak, P. Pandurang; Plaunt, Christian; Williams, Brian C.; Lau, Sonie (Technical Monitor)

1998-01-01

The New Millennium Remote Agent (NMRA) will be the first AI system to control an actual spacecraft. The spacecraft domain places a strong premium on autonomy and requires dynamic recoveries and robust concurrent execution, all in the presence of tight real-time deadlines, changing goals, scarce resource constraints, and a wide variety of possible failures. To achieve this level of execution robustness, we have integrated a procedural executive based on generic procedures with a deductive model-based executive. A procedural executive provides sophisticated control constructs such as loops, parallel activity, locks, and synchronization which are used for robust schedule execution, hierarchical task decomposition, and routine configuration management. A deductive executive provides algorithms for sophisticated state inference and optimal failure recover), planning. The integrated executive enables designers to code knowledge via a combination of procedures and declarative models, yielding a rich modeling capability suitable to the challenges of real spacecraft control. The interface between the two executives ensures both that recovery sequences are smoothly merged into high-level schedule execution and that a high degree of reactivity is retained to effectively handle additional failures during recovery.

A study of workstation computational performance for real-time flight simulation

NASA Technical Reports Server (NTRS)

Maddalon, Jeffrey M.; Cleveland, Jeff I., II

1995-01-01

With recent advances in microprocessor technology, some have suggested that modern workstations provide enough computational power to properly operate a real-time simulation. This paper presents the results of a computational benchmark, based on actual real-time flight simulation code used at Langley Research Center, which was executed on various workstation-class machines. The benchmark was executed on different machines from several companies including: CONVEX Computer Corporation, Cray Research, Digital Equipment Corporation, Hewlett-Packard, Intel, International Business Machines, Silicon Graphics, and Sun Microsystems. The machines are compared by their execution speed, computational accuracy, and porting effort. The results of this study show that the raw computational power needed for real-time simulation is now offered by workstations.

A Conceptual Level Design for a Static Scheduler for Hard Real-Time Systems

DTIC Science & Technology

1988-03-01

The design of hard real - time systems is gaining a great deal of attention in the software engineering field as more and more real-world processes are...for these hard real - time systems . PSDL, as an executable design language, is supported by an execution support system consisting of a static scheduler, dynamic scheduler, and translator.

Choosing a software design method for real-time Ada applications: JSD process inversion as a means to tailor a design specification to the performance requirements and target machine

NASA Technical Reports Server (NTRS)

Withey, James V.

1986-01-01

The validity of real-time software is determined by its ability to execute on a computer within the time constraints of the physical system it is modeling. In many applications the time constraints are so critical that the details of process scheduling are elevated to the requirements analysis phase of the software development cycle. It is not uncommon to find specifications for a real-time cyclic executive program included to assumed in such requirements. It was found that prelininary designs structured around this implementation abscure the data flow of the real world system that is modeled and that it is consequently difficult and costly to maintain, update and reuse the resulting software. A cyclic executive is a software component that schedules and implicitly synchronizes the real-time software through periodic and repetitive subroutine calls. Therefore a design method is sought that allows the deferral of process scheduling to the later stages of design. The appropriate scheduling paradigm must be chosen given the performance constraints, the largest environment and the software's lifecycle. The concept of process inversion is explored with respect to the cyclic executive.

META-GLARE: A meta-system for defining your own computer interpretable guideline system-Architecture and acquisition.

PubMed

Bottrighi, Alessio; Terenziani, Paolo

2016-09-01

Several different computer-assisted management systems of computer interpretable guidelines (CIGs) have been developed by the Artificial Intelligence in Medicine community. Each CIG system is characterized by a specific formalism to represent CIGs, and usually provides a manager to acquire, consult and execute them. Though there are several commonalities between most formalisms in the literature, each formalism has its own peculiarities. The goal of our work is to provide a flexible support to the extension or definition of CIGs formalisms, and of their acquisition and execution engines. Instead of defining "yet another CIG formalism and its manager", we propose META-GLARE (META Guideline Acquisition, Representation, and Execution), a "meta"-system to define new CIG systems. In this paper, META-GLARE, a meta-system to define new CIG systems, is presented. We try to capture the commonalities among current CIG approaches, by providing (i) a general manager for the acquisition, consultation and execution of hierarchical graphs (representing the control flow of actions in CIGs), parameterized over the types of nodes and of arcs constituting it, and (ii) a library of different elementary components of guidelines nodes (actions) and arcs, in which each type definition involves the specification of how objects of this type can be acquired, consulted and executed. We provide generality and flexibility, by allowing free aggregations of such elementary components to define new primitive node and arc types. We have drawn several experiments, in which we have used META-GLARE to build a CIG system (Experiment 1 in Section 8), or to extend it (Experiments 2 and 3). Such experiments show that META-GLARE provides a useful and easy-to-use support to such tasks. For instance, re-building the Guideline Acquisition, Representation, and Execution (GLARE) system using META-GLARE required less than one day (Experiment 1). META-GLARE is a meta-system for CIGs supporting fast prototyping. Since META-GLARE provides acquisition and execution engines that are parametric over the specific CIG formalism, it supports easy update and construction of CIG systems. Copyright © 2016 Elsevier B.V. All rights reserved.

Implications of the Turing machine model of computation for processor and programming language design

NASA Astrophysics Data System (ADS)

Hunter, Geoffrey

2004-01-01

A computational process is classified according to the theoretical model that is capable of executing it; computational processes that require a non-predeterminable amount of intermediate storage for their execution are Turing-machine (TM) processes, while those whose storage are predeterminable are Finite Automation (FA) processes. Simple processes (such as traffic light controller) are executable by Finite Automation, whereas the most general kind of computation requires a Turing Machine for its execution. This implies that a TM process must have a non-predeterminable amount of memory allocated to it at intermediate instants of its execution; i.e. dynamic memory allocation. Many processes encountered in practice are TM processes. The implication for computational practice is that the hardware (CPU) architecture and its operating system must facilitate dynamic memory allocation, and that the programming language used to specify TM processes must have statements with the semantic attribute of dynamic memory allocation, for in Alan Turing"s thesis on computation (1936) the "standard description" of a process is invariant over the most general data that the process is designed to process; i.e. the program describing the process should never have to be modified to allow for differences in the data that is to be processed in different instantiations; i.e. data-invariant programming. Any non-trivial program is partitioned into sub-programs (procedures, subroutines, functions, modules, etc). Examination of the calls/returns between the subprograms reveals that they are nodes in a tree-structure; this tree-structure is independent of the programming language used to encode (define) the process. Each sub-program typically needs some memory for its own use (to store values intermediate between its received data and its computed results); this locally required memory is not needed before the subprogram commences execution, and it is not needed after its execution terminates; it may be allocated as its execution commences, and deallocated as its execution terminates, and if the amount of this local memory is not known until just before execution commencement, then it is essential that it be allocated dynamically as the first action of its execution. This dynamically allocated/deallocated storage of each subprogram"s intermediate values, conforms with the stack discipline; i.e. last allocated = first to be deallocated, an incidental benefit of which is automatic overlaying of variables. This stack-based dynamic memory allocation was a semantic implication of the nested block structure that originated in the ALGOL-60 programming language. AGLOL-60 was a TM language, because the amount of memory allocated on subprogram (block/procedure) entry (for arrays, etc) was computable at execution time. A more general requirement of a Turing machine process is for code generation at run-time; this mandates access to the source language processor (compiler/interpretor) during execution of the process. This fundamental aspect of computer science is important to the future of system design, because it has been overlooked throughout the 55 years since modern computing began in 1048. The popular computer systems of this first half-century of computing were constrained by compile-time (or even operating system boot-time) memory allocation, and were thus limited to executing FA processes. The practical effect was that the distinction between the data-invariant program and its variable data was blurred; programmers had to make trial and error executions, modifying the program"s compile-time constants (array dimensions) to iterate towards the values required at run-time by the data being processed. This era of trial and error computing still persists; it pervades the culture of current (2003) computing practice.

Fast MPEG-CDVS Encoder With GPU-CPU Hybrid Computing.

PubMed

Duan, Ling-Yu; Sun, Wei; Zhang, Xinfeng; Wang, Shiqi; Chen, Jie; Yin, Jianxiong; See, Simon; Huang, Tiejun; Kot, Alex C; Gao, Wen

2018-05-01

The compact descriptors for visual search (CDVS) standard from ISO/IEC moving pictures experts group has succeeded in enabling the interoperability for efficient and effective image retrieval by standardizing the bitstream syntax of compact feature descriptors. However, the intensive computation of a CDVS encoder unfortunately hinders its widely deployment in industry for large-scale visual search. In this paper, we revisit the merits of low complexity design of CDVS core techniques and present a very fast CDVS encoder by leveraging the massive parallel execution resources of graphics processing unit (GPU). We elegantly shift the computation-intensive and parallel-friendly modules to the state-of-the-arts GPU platforms, in which the thread block allocation as well as the memory access mechanism are jointly optimized to eliminate performance loss. In addition, those operations with heavy data dependence are allocated to CPU for resolving the extra but non-necessary computation burden for GPU. Furthermore, we have demonstrated the proposed fast CDVS encoder can work well with those convolution neural network approaches which enables to leverage the advantages of GPU platforms harmoniously, and yield significant performance improvements. Comprehensive experimental results over benchmarks are evaluated, which has shown that the fast CDVS encoder using GPU-CPU hybrid computing is promising for scalable visual search.

A FAST POLYNOMIAL TRANSFORM PROGRAM WITH A MODULARIZED STRUCTURE

NASA Technical Reports Server (NTRS)

Truong, T. K.

1994-01-01

This program utilizes a fast polynomial transformation (FPT) algorithm applicable to two-dimensional mathematical convolutions. Two-dimensional convolution has many applications, particularly in image processing. Two-dimensional cyclic convolutions can be converted to a one-dimensional convolution in a polynomial ring. Traditional FPT methods decompose the one-dimensional cyclic polynomial into polynomial convolutions of different lengths. This program will decompose a cyclic polynomial into polynomial convolutions of the same length. Thus, only FPTs and Fast Fourier Transforms of the same length are required. This modular approach can save computational resources. To further enhance its appeal, the program is written in the transportable 'C' language. The steps in the algorithm are: 1) formulate the modulus reduction equations, 2) calculate the polynomial transforms, 3) multiply the transforms using a generalized fast Fourier transformation, 4) compute the inverse polynomial transforms, and 5) reconstruct the final matrices using the Chinese remainder theorem. Input to this program is comprised of the row and column dimensions and the initial two matrices. The matrices are printed out at all steps, ending with the final reconstruction. This program is written in 'C' for batch execution and has been implemented on the IBM PC series of computers under DOS with a central memory requirement of approximately 18K of 8 bit bytes. This program was developed in 1986.

The reluctant entrepreneur.

PubMed

Veit, K

1992-01-01

Unlike a lot of corporate executives, Ken Veit never longed to be his own boss. But after 30 years on the fast track, he lost his high-powered job at one of the world's largest insurance companies and was forced to take an entrepreneurial leap of faith. In 1989, Veit signed a franchise agreement to own and operate a Cartoon Corner store in a mall in Scottsdale, Arizona. Cartoon Corner was based on the Disney store idea, but it carried hundreds of products featuring cartoon characters from every movie studio. Most important, Cartoon Corner offered extensive training and an elaborate management support system for its franchisees. The company planned to franchise 100 stores over the next few years, then go public. If all went well, its young executives claimed, the Cartoon Corner chain would build a market valuation of up to $100 million by the mid-1990s. In addition, the mall, which was in the planning stages when Veit signed on, was supposed to become a new kind of entertainment mall, with seven movie theaters, a space-flight simulator, and a shark-filled aquarium. It had all sounded too good to be true--and it was. Despite Veit's careful forecasting, he suffered a series of unexpected catastrophes. The mall failed to keep its promises. The franchisor lost its venture capital. The Gulf War dried up retail traffic. But it was too late to back out. Veit went forward on his own, truly alone for the first time in his life. When the mall and his store finally opened in May 1991, they did so in the midst of a recession. Despite the inspirational stories of other former executives, Veit has learned that the life of an entrepreneur is not all it's cracked up to be. As he notes, "I began with well-above-average experience, a proven concept, and excellent capitalization, yet in my case, personal bankruptcy remains a distinct possibility."

Applications of the pipeline environment for visual informatics and genomics computations

PubMed Central

2011-01-01

Background Contemporary informatics and genomics research require efficient, flexible and robust management of large heterogeneous data, advanced computational tools, powerful visualization, reliable hardware infrastructure, interoperability of computational resources, and detailed data and analysis-protocol provenance. The Pipeline is a client-server distributed computational environment that facilitates the visual graphical construction, execution, monitoring, validation and dissemination of advanced data analysis protocols. Results This paper reports on the applications of the LONI Pipeline environment to address two informatics challenges - graphical management of diverse genomics tools, and the interoperability of informatics software. Specifically, this manuscript presents the concrete details of deploying general informatics suites and individual software tools to new hardware infrastructures, the design, validation and execution of new visual analysis protocols via the Pipeline graphical interface, and integration of diverse informatics tools via the Pipeline eXtensible Markup Language syntax. We demonstrate each of these processes using several established informatics packages (e.g., miBLAST, EMBOSS, mrFAST, GWASS, MAQ, SAMtools, Bowtie) for basic local sequence alignment and search, molecular biology data analysis, and genome-wide association studies. These examples demonstrate the power of the Pipeline graphical workflow environment to enable integration of bioinformatics resources which provide a well-defined syntax for dynamic specification of the input/output parameters and the run-time execution controls. Conclusions The LONI Pipeline environment http://pipeline.loni.ucla.edu provides a flexible graphical infrastructure for efficient biomedical computing and distributed informatics research. The interactive Pipeline resource manager enables the utilization and interoperability of diverse types of informatics resources. The Pipeline client-server model provides computational power to a broad spectrum of informatics investigators - experienced developers and novice users, user with or without access to advanced computational-resources (e.g., Grid, data), as well as basic and translational scientists. The open development, validation and dissemination of computational networks (pipeline workflows) facilitates the sharing of knowledge, tools, protocols and best practices, and enables the unbiased validation and replication of scientific findings by the entire community. PMID:21791102

GPU accelerated generation of digitally reconstructed radiographs for 2-D/3-D image registration.

PubMed

Dorgham, Osama M; Laycock, Stephen D; Fisher, Mark H

2012-09-01

Recent advances in programming languages for graphics processing units (GPUs) provide developers with a convenient way of implementing applications which can be executed on the CPU and GPU interchangeably. GPUs are becoming relatively cheap, powerful, and widely available hardware components, which can be used to perform intensive calculations. The last decade of hardware performance developments shows that GPU-based computation is progressing significantly faster than CPU-based computation, particularly if one considers the execution of highly parallelisable algorithms. Future predictions illustrate that this trend is likely to continue. In this paper, we introduce a way of accelerating 2-D/3-D image registration by developing a hybrid system which executes on the CPU and utilizes the GPU for parallelizing the generation of digitally reconstructed radiographs (DRRs). Based on the advancements of the GPU over the CPU, it is timely to exploit the benefits of many-core GPU technology by developing algorithms for DRR generation. Although some previous work has investigated the rendering of DRRs using the GPU, this paper investigates approximations which reduce the computational overhead while still maintaining a quality consistent with that needed for 2-D/3-D registration with sufficient accuracy to be clinically acceptable in certain applications of radiation oncology. Furthermore, by comparing implementations of 2-D/3-D registration on the CPU and GPU, we investigate current performance and propose an optimal framework for PC implementations addressing the rigid registration problem. Using this framework, we are able to render DRR images from a 256×256×133 CT volume in ~24 ms using an NVidia GeForce 8800 GTX and in ~2 ms using NVidia GeForce GTX 580. In addition to applications requiring fast automatic patient setup, these levels of performance suggest image-guided radiation therapy at video frame rates is technically feasible using relatively low cost PC architecture.

Multi-INT Complex Event Processing using Approximate, Incremental Graph Pattern Search

DTIC Science & Technology

2012-06-01

graph pattern search and SPARQL queries . Total execution time for 10 executions each of 5 random pattern searches in synthetic data sets...01/11 1000 10000 100000 RDF triples Time (secs) 10 20 Graph pattern algorithm SPARQL queries Initial Performance Comparisons 09/18/11 2011 Thrust Area

Siblings, Theory of Mind, and Executive Functioning in Children Aged 3-6 Years: New Longitudinal Evidence

ERIC Educational Resources Information Center

McAlister, Anna R.; Peterson, Candida C.

2013-01-01

Longitudinal data were obtained from 157 children aged 3 years 3 months to 5 years 6 months at Time 1. At Time 2 these children had aged an average of 12 months. Theory of mind (ToM) and executive functioning (EF) were measured at both time points. Results suggest that Time 1 ToM scores predict Time 2 EF scores. Detailed examination of sibling…

Impact of Elevated Core Body Temperature on Attention Networks.

PubMed

Liu, Kai; Jiang, Qingjun; Li, Li; Li, Bo; Yang, Zhen; Qian, Shaowen; Li, Min; Sun, Gang

2015-12-01

Cognitive function can be impaired after passive heat exposure and with an elevation in core body temperature (Tcore). This study examined the dynamic correlation among passive heat exposure, Tcore, and cognition. We gave the Attention Network Test of alerting, orienting, and executive control to five groups of five young men who were being exposed to a hyperthermic condition (50°C, 40% relative humidity) for 0, 10, 20, 30, or 40 minutes. We used the participants' reaction time, accuracy (correct responses), efficiency (accuracy÷reaction time), and Tcore to estimate optimal curve models for best fit of data. We could not estimate an appropriate curve model for either alerting or orienting with Tcore, change in Tcore, or duration of passive heat exposure. We estimated quadratic models for Tcore and duration (adjusted R=0.752), change in Tcore and duration (0.906), executive control score and duration (0.509), and efficiency of executive control and duration (0.293). We estimated linear models for executive control score and Tcore (0.479), efficiency of executive control and Tcore (0.261), executive control score and change in Tcore (0.279), and efficiency of executive control and change in Tcore (0.262). Different attentional abilities had different sensitivities to thermal stress. Executive control of attention deteriorated linearly with a rise in Tcore within the normal physiologic range, but deteriorated nonlinearly with longer passive heat exposure.

Embedding Temporal Constraints For Coordinated Execution in Habitat Automation

NASA Technical Reports Server (NTRS)

Morris, Paul; Schwabacher, Mark; Dalal, Michael; Fry, Charles

2013-01-01

Future NASA plans call for long-duration deep space missions with human crews. Because of light-time delay and other considerations, increased autonomy will be needed. This will necessitate integration of tools in such areas as anomaly detection, diagnosis, planning, and execution. In this paper we investigate an approach that integrates planning and execution by embedding planner-derived temporal constraints in an execution procedure. To avoid the need for propagation, we convert the temporal constraints to dispatchable form. We handle some uncertainty in the durations without it affecting the execution; larger variations may cause activities to be skipped.

EYE-TRAC: monitoring attention and utility for mTBI

NASA Astrophysics Data System (ADS)

Maruta, Jun; Tong, Jianliang; Lee, Stephanie W.; Iqbal, Zarah; Schonberger, Alison; Ghajar, Jamshid

2012-06-01

Attention is a core function in cognition and also the most prevalent cognitive deficit in mild traumatic brain injury (mTBI). Predictive timing is an essential element of attention functioning because sensory processing and execution of goal-oriented behavior are facilitated by temporally accurate prediction. It is hypothesized that impaired synchronization between prediction and external events accounts for the attention deficit in mTBI. Other cognitive and somatic or affective symptoms associated with mTBI may be explained as secondary consequences of impaired predictive timing. Eye-Tracking Rapid Attention Computation (EYE-TRAC) is the quantification of predictive timing with indices of dynamic visuo-motor synchronization (DVS) between the gaze and the target during continuous predictive visual tracking. Such quantification allows for cognitive performance monitoring in comparison to the overall population as well as within individuals over time. We report preliminary results of normative data and data collected from subjects with a history of mTBI within 2 weeks of injury and post-concussive symptoms at the time of recruitment. A substantial proportion of mTBI subjects demonstrated DVS scores worse than 95% of normal subjects. In addition, longitudinal monitoring of acute mTBI subjects showed that initially abnormal DVS scores were followed by improvement toward the normal range. In summary, EYE-TRAC provides fast and objective indices of DVS that allow comparison of attention performance to a normative standard and monitoring of within-individual changes.

FASTING IN ELECTIVE SURGICAL PATIENTS: COMPARISON AMONG THE TIME PRESCRIBED, PERFORMED AND RECOMMENDED ON PERIOPERATIVE CARE PROTOCOLS

PubMed Central

FRANCISCO, Saionara Cristina; BATISTA, Sandra Teixeira; PENA, Geórgia das Graças

2015-01-01

Background: Prolonged preoperative fasting may impair nutritional status of the patient and their recovery. In contrast, some studies show that fasting abbreviation can improve the response to trauma and decrease the length of hospital stay. Aim: Investigate whether the prescribed perioperative fasting time and practiced by patients is in compliance with current multimodal protocols and identify the main factors associated. Methods: Cross-sectional study with 65 patients undergoing elective surgery of the digestive tract or abdominal wall. We investigated the fasting time in the perioperative period, hunger and thirst reports, physical status, diabetes diagnosis, type of surgery and anesthesia. Results: The patients were between 19 and 87 years, mostly female (73.8%). The most performed procedure was cholecystectomy (47.69%) and general anesthesia the most used (89.23%). The most common approach was to start fasting from midnight for liquids and solids, and most of the patients received grade II (64.6%) to the physical state. The real fasting average time was 16 h (9.5-41.58) was higher than prescribed (11 h, 6.58 -26.75). The patients submitted to surgery in the afternoon were in more fasting time than those who did in the morning (p<0.001). The intensity of hunger and thirst increased in postoperative fasting period (p=0.010 and 0.027). The average period of postoperative fasting was 18.25 h (3.33-91.83) and only 23.07% restarted feeding on the same day. Conclusion: Patients were fasted for prolonged time, higher even than the prescribed time and intensity of the signs of discomfort such as hunger and thirst increased over time. To better recovery and the patient's well-being, it is necessary to establish a preoperative fasting abbreviation protocol. PMID:26734794

Efficiently Scheduling Multi-core Guest Virtual Machines on Multi-core Hosts in Network Simulation

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

Yoginath, Srikanth B; Perumalla, Kalyan S

2011-01-01

Virtual machine (VM)-based simulation is a method used by network simulators to incorporate realistic application behaviors by executing actual VMs as high-fidelity surrogates for simulated end-hosts. A critical requirement in such a method is the simulation time-ordered scheduling and execution of the VMs. Prior approaches such as time dilation are less efficient due to the high degree of multiplexing possible when multiple multi-core VMs are simulated on multi-core host systems. We present a new simulation time-ordered scheduler to efficiently schedule multi-core VMs on multi-core real hosts, with a virtual clock realized on each virtual core. The distinguishing features of ourmore » approach are: (1) customizable granularity of the VM scheduling time unit on the simulation time axis, (2) ability to take arbitrary leaps in virtual time by VMs to maximize the utilization of host (real) cores when guest virtual cores idle, and (3) empirically determinable optimality in the tradeoff between total execution (real) time and time-ordering accuracy levels. Experiments show that it is possible to get nearly perfect time-ordered execution, with a slight cost in total run time, relative to optimized non-simulation VM schedulers. Interestingly, with our time-ordered scheduler, it is also possible to reduce the time-ordering error from over 50% of non-simulation scheduler to less than 1% realized by our scheduler, with almost the same run time efficiency as that of the highly efficient non-simulation VM schedulers.« less

Time and Memory Efficient Online Piecewise Linear Approximation of Sensor Signals.

PubMed

Grützmacher, Florian; Beichler, Benjamin; Hein, Albert; Kirste, Thomas; Haubelt, Christian

2018-05-23

Piecewise linear approximation of sensor signals is a well-known technique in the fields of Data Mining and Activity Recognition. In this context, several algorithms have been developed, some of them with the purpose to be performed on resource constrained microcontroller architectures of wireless sensor nodes. While microcontrollers are usually constrained in computational power and memory resources, all state-of-the-art piecewise linear approximation techniques either need to buffer sensor data or have an execution time depending on the segment’s length. In the paper at hand, we propose a novel piecewise linear approximation algorithm, with a constant computational complexity as well as a constant memory complexity. Our proposed algorithm’s worst-case execution time is one to three orders of magnitude smaller and its average execution time is three to seventy times smaller compared to the state-of-the-art Piecewise Linear Approximation (PLA) algorithms in our experiments. In our evaluations, we show that our algorithm is time and memory efficient without sacrificing the approximation quality compared to other state-of-the-art piecewise linear approximation techniques, while providing a maximum error guarantee per segment, a small parameter space of only one parameter, and a maximum latency of one sample period plus its worst-case execution time.

IGA-ADS: Isogeometric analysis FEM using ADS solver

NASA Astrophysics Data System (ADS)

Łoś, Marcin M.; Woźniak, Maciej; Paszyński, Maciej; Lenharth, Andrew; Hassaan, Muhamm Amber; Pingali, Keshav

2017-08-01

In this paper we present a fast explicit solver for solution of non-stationary problems using L2 projections with isogeometric finite element method. The solver has been implemented within GALOIS framework. It enables parallel multi-core simulations of different time-dependent problems, in 1D, 2D, or 3D. We have prepared the solver framework in a way that enables direct implementation of the selected PDE and corresponding boundary conditions. In this paper we describe the installation, implementation of exemplary three PDEs, and execution of the simulations on multi-core Linux cluster nodes. We consider three case studies, including heat transfer, linear elasticity, as well as non-linear flow in heterogeneous media. The presented package generates output suitable for interfacing with Gnuplot and ParaView visualization software. The exemplary simulations show near perfect scalability on Gilbert shared-memory node with four Intel® Xeon® CPU E7-4860 processors, each possessing 10 physical cores (for a total of 40 cores).

Unsupervised, Robust Estimation-based Clustering for Multispectral Images

NASA Technical Reports Server (NTRS)

Netanyahu, Nathan S.

1997-01-01

To prepare for the challenge of handling the archiving and querying of terabyte-sized scientific spatial databases, the NASA Goddard Space Flight Center's Applied Information Sciences Branch (AISB, Code 935) developed a number of characterization algorithms that rely on supervised clustering techniques. The research reported upon here has been aimed at continuing the evolution of some of these supervised techniques, namely the neural network and decision tree-based classifiers, plus extending the approach to incorporating unsupervised clustering algorithms, such as those based on robust estimation (RE) techniques. The algorithms developed under this task should be suited for use by the Intelligent Information Fusion System (IIFS) metadata extraction modules, and as such these algorithms must be fast, robust, and anytime in nature. Finally, so that the planner/schedule module of the IlFS can oversee the use and execution of these algorithms, all information required by the planner/scheduler must be provided to the IIFS development team to ensure the timely integration of these algorithms into the overall system.

Fast access to the CMS detector condition data employing HTML5 technologies

NASA Astrophysics Data System (ADS)

Pierro, Giuseppe Antonio; Cavallari, Francesca; Di Guida, Salvatore; Innocente, Vincenzo

2011-12-01

This paper focuses on using HTML version 5 (HTML5) for accessing condition data for the CMS experiment, evaluating the benefits and risks posed by the use of this technology. According to the authors of HTML5, this technology attempts to solve issues found in previous iterations of HTML and addresses the needs of web applications, an area previously not adequately covered by HTML. We demonstrate that employing HTML5 brings important benefits in terms of access performance to the CMS condition data. The combined use of web storage and web sockets allows increasing the performance and reducing the costs in term of computation power, memory usage and network bandwidth for client and server. Above all, the web workers allow creating different scripts that can be executed using multi-thread mode, exploiting multi-core microprocessors. Web workers have been employed in order to substantially decrease the web page rendering time to display the condition data stored in the CMS condition database.

Concurrent and Accurate Short Read Mapping on Multicore Processors.

PubMed

Martínez, Héctor; Tárraga, Joaquín; Medina, Ignacio; Barrachina, Sergio; Castillo, Maribel; Dopazo, Joaquín; Quintana-Ortí, Enrique S

2015-01-01

We introduce a parallel aligner with a work-flow organization for fast and accurate mapping of RNA sequences on servers equipped with multicore processors. Our software, HPG Aligner SA (HPG Aligner SA is an open-source application. The software is available at http://www.opencb.org, exploits a suffix array to rapidly map a large fraction of the RNA fragments (reads), as well as leverages the accuracy of the Smith-Waterman algorithm to deal with conflictive reads. The aligner is enhanced with a careful strategy to detect splice junctions based on an adaptive division of RNA reads into small segments (or seeds), which are then mapped onto a number of candidate alignment locations, providing crucial information for the successful alignment of the complete reads. The experimental results on a platform with Intel multicore technology report the parallel performance of HPG Aligner SA, on RNA reads of 100-400 nucleotides, which excels in execution time/sensitivity to state-of-the-art aligners such as TopHat 2+Bowtie 2, MapSplice, and STAR.

Vortex Formation and Acceleration of a Fish-Inspired Robot Performing Starts from Rest

NASA Astrophysics Data System (ADS)

Devoria, Adam; Bapst, Jonathan; Ringuette, Matthew

2009-11-01

We investigate the unsteady flow of a fish-inspired robot executing starts from rest, with the objective of understanding the connection among the kinematics, vortex formation, and acceleration performance. Several fish perform ``fast starts,'' where the body bends into a ``C'' or ``S'' shape while turning (phase I), followed by a straightening of the body and caudal fin and a linear acceleration (phase II). The resulting highly 3-D, unsteady vortex formation and its relationship to the acceleration are not well understood. The self-propelled robotic model contains motor-driven joints with programmable motion to emulate phase II of a simplified C-start. The experiments are conducted in a water tank, and the model is constrained to 1 direction along rails. The velocity is measured using digital particle image velocimetry (DPIV) in multiple planes. Vortex boundaries are identified using the finite-time Lyapunov exponent, then the unsteady vortex circulation is computed. The thrust is estimated from the identified vortices, and correlated with the circulation and model acceleration for different kinematics.

Putting time into proof outlines

NASA Technical Reports Server (NTRS)

Schneider, Fred B.; Bloom, Bard; Marzullo, Keith

1993-01-01

A logic for reasoning about timing properties of concurrent programs is presented. The logic is based on Hoare-style proof outlines and can handle maximal parallelism as well as certain resource-constrained execution environments. The correctness proof for a mutual exclusion protocol that uses execution timings in a subtle way illustrates the logic in action. A soundness proof using structural operational semantics is outlined in the appendix.

Executive function processes predict mobility outcomes in older adults.

PubMed

Gothe, Neha P; Fanning, Jason; Awick, Elizabeth; Chung, David; Wójcicki, Thomas R; Olson, Erin A; Mullen, Sean P; Voss, Michelle; Erickson, Kirk I; Kramer, Arthur F; McAuley, Edward

2014-02-01

To examine the relationship between performance on executive function measures and subsequent mobility outcomes in community-dwelling older adults. Randomized controlled clinical trial. Champaign-Urbana, Illinois. Community-dwelling older adults (N = 179; mean age 66.4). A 12-month exercise trial with two arms: an aerobic exercise group and a stretching and strengthening group. Established cognitive tests of executive function (flanker task, task switching, and a dual-task paradigm) and the Wisconsin card sort test. Mobility was assessed using the timed 8-foot up and go test and times to climb up and down a flight of stairs. Participants completed the cognitive tests at baseline and the mobility measures at baseline and after 12 months of the intervention. Multiple regression analyses were conducted to determine whether baseline executive function predicted postintervention functional performance after controlling for age, sex, education, cardiorespiratory fitness, and baseline mobility levels. Selective baseline executive function measurements, particularly performance on the flanker task (β = 0.15-0.17) and the Wisconsin card sort test (β = 0.11-0.16) consistently predicted mobility outcomes at 12 months. The estimates were in the expected direction, such that better baseline performance on the executive function measures predicted better performance on the timed mobility tests independent of intervention. Executive functions of inhibitory control, mental set shifting, and attentional flexibility were predictive of functional mobility. Given the literature associating mobility limitations with disability, morbidity, and mortality, these results are important for understanding the antecedents to poor mobility function that well-designed interventions to improve cognitive performance can attenuate. © 2014, Copyright the Authors Journal compilation © 2014, The American Geriatrics Society.

Leadership Characteristics for Health Care Managers: Perspectives of Chief Executive Officers in US Hospitals.

PubMed

Collins, Sandra K; McKinnies, Richard; Collins, Kevin S

2015-01-01

A study was conducted to determine the perceptions of chief executive officers in US hospitals regarding the most important characteristics aspiring health care executives should possess. The results of this 2012 study were compared with a previous study conducted in 2007 to determine if the perceptions had changed over time.

Fast prediction of pulsed nonlinear acoustic fields from clinically relevant sources using Time-Averaged Wave Envelope approach: comparison of numerical simulations and experimental results

PubMed Central

Wójcik, J.; Kujawska, T.; Nowicki, A.; Lewin, P.A.

2008-01-01

The primary goal of this work was to verify experimentally the applicability of the recently introduced Time-Averaged Wave Envelope (TAWE) method [1] as a tool for fast prediction of four dimensional (4D) pulsed nonlinear pressure fields from arbitrarily shaped acoustic sources in attenuating media. The experiments were performed in water at the fundamental frequency of 2.8 MHz for spherically focused (focal length F = 80 mm) square (20 × 20 mm) and rectangular (10 × 25 mm) sources similar to those used in the design of 1D linear arrays operating with ultrasonic imaging systems. The experimental results obtained with 10-cycle tone bursts at three different excitation levels corresponding to linear, moderately nonlinear and highly nonlinear propagation conditions (0.045, 0.225 and 0.45 MPa on-source pressure amplitude, respectively) were compared with those yielded using the TAWE approach [1]. The comparison of the experimental results and numerical simulations has shown that the TAWE approach is well suited to predict (to within ± 1 dB) both the spatial-temporal and spatial-spectral pressure variations in the pulsed nonlinear acoustic beams. The obtained results indicated that implementation of the TAWE approach enabled shortening of computation time in comparison with the time needed for prediction of the full 4D pulsed nonlinear acoustic fields using a conventional (Fourier-series) approach [2]. The reduction in computation time depends on several parameters, including the source geometry, dimensions, fundamental resonance frequency, excitation level as well as the strength of the medium nonlinearity. For the non-axisymmetric focused transducers mentioned above and excited by a tone burst corresponding to moderately nonlinear and highly nonlinear conditions the execution time of computations was 3 and 12 hours, respectively, when using a 1.5 GHz clock frequency, 32-bit processor PC laptop with 2 GB RAM memory, only. Such prediction of the full 4D pulsed field is not possible when using conventional, Fourier-series scheme as it would require increasing the RAM memory by at least 2 orders of magnitude. PMID:18474387

Implementation of and Ada real-time executive: A case study

NASA Technical Reports Server (NTRS)

Laird, James D.; Burton, Bruce A.; Koppes, Mary R.

1986-01-01

Current Ada language implementations and runtime environments are immature, unproven and are a key risk area for real-time embedded computer system (ECS). A test-case environment is provided in which the concerns of the real-time, ECS community are addressed. A priority driven executive is selected to be implemented in the Ada programming language. The model selected is representative of real-time executives tailored for embedded systems used missile, spacecraft, and avionics applications. An Ada-based design methodology is utilized, and two designs are considered. The first of these designs requires the use of vendor supplied runtime and tasking support. An alternative high-level design is also considered for an implementation requiring no vendor supplied runtime or tasking support. The former approach is carried through to implementation.

Task-dependent activation of distinct fast and slow(er) motor pathways during motor imagery.

PubMed

Keller, Martin; Taube, Wolfgang; Lauber, Benedikt

2018-02-22

Motor imagery and actual movements share overlapping activation of brain areas but little is known about task-specific activation of distinct motor pathways during mental simulation of movements. For real contractions, it was demonstrated that the slow(er) motor pathways are activated differently in ballistic compared to tonic contractions but it is unknown if this also holds true for imagined contractions. The aim of the present study was to assess the activity of fast and slow(er) motor pathways during mentally simulated movements of ballistic and tonic contractions. H-reflexes were conditioned with transcranial magnetic stimulation at different interstimulus intervals to assess the excitability of fast and slow(er) motor pathways during a) the execution of tonic and ballistic contractions, b) motor imagery of these contraction types, and c) at rest. In contrast to the fast motor pathways, the slow(er) pathways displayed a task-specific activation: for imagined ballistic as well as real ballistic contractions, the activation was reduced compared to rest whereas enhanced activation was found for imagined tonic and real tonic contractions. This study provides evidence that the excitability of fast and slow(er) motor pathways during motor imagery resembles the activation pattern observed during real contractions. The findings indicate that motor imagery results in task- and pathway-specific subliminal activation of distinct subsets of neurons in the primary motor cortex. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Replacing sedentary time with sleep, light, or moderate-to-vigorous physical activity: effects on self-regulation and executive functioning.

PubMed

Fanning, J; Porter, G; Awick, E A; Ehlers, D K; Roberts, S A; Cooke, G; Burzynska, A Z; Voss, M W; Kramer, A F; McAuley, E

2017-04-01

Recent attention has highlighted the importance of reducing sedentary time for maintaining health and quality of life. However, it is unclear how changing sedentary behavior may influence executive functions and self-regulatory strategy use, which are vital for the long-term maintenance of a health behavior regimen. The purpose of this cross-sectional study is to examine the estimated self-regulatory and executive functioning effects of substituting 30 min of sedentary behavior with 30 min of light activity, moderate-to-vigorous physical activity (MVPA), or sleep in a sample of older adults. This study reports baseline data collected from low-active healthy older adults (N = 247, mean age 65.4 ± 4.6 years) recruited to participate in a 6 month randomized controlled exercise trial examining the effects of various modes of exercise on brain health and function. Each participant completed assessments of physical activity self-regulatory strategy use (i.e., self-monitoring, goal-setting, social support, reinforcement, time management, and relapse prevention) and executive functioning. Physical activity and sedentary behaviors were measured using accelerometers during waking hours for seven consecutive days at each time point. Isotemporal substitution analyses were conducted to examine the effect on self-regulation and executive functioning should an individual substitute sedentary time with light activity, MVPA, or sleep. The substitution of sedentary time with both sleep and MVPA influenced both self-regulatory strategy use and executive functioning. Sleep was associated with greater self-monitoring (B = .23, p = .02), goal-setting (B = .32, p < .01), and social support (B = .18, p = .01) behaviors. Substitution of sedentary time with MVPA was associated with higher accuracy on 2-item (B = .03, p = .01) and 3-item (B = .02, p = .04) spatial working memory tasks, and with faster reaction times on single (B = -23.12, p = .03) and mixed-repeated task-switching blocks (B = -27.06, p = .04). Substitution of sedentary time with sleep was associated with marginally faster reaction time on mixed-repeated task-switching blocks (B = -12.20, p = .07) and faster reaction time on mixed-switch blocks (B = 17.21, p = .05), as well as reduced global reaction time switch cost (B = -16.86, p = .01). Substitution for light intensity physical activity did not produce significant effects. By replacing sedentary time with sleep and MVPA, individuals may bolster several important domains of self-regulatory behavior and executive functioning. This has important implications for the design of long-lasting health behavior interventions. Trial Registration clinicaltrials.gov identifier NCT00438347.

Neuropsychological assessment of executive functions following pediatric traumatic brain injury.

PubMed

Gaines, K Drorit; Soper, Henry V

2018-01-01

Assessment of executive functions in the adult is best captured at the stage where full maturation of brain development occurs. Assessment of executive functions of children, however, is considerably more complicated. First, assessment of executive functioning in children represents a snapshot of these developing functions at a particular time linked stage, which may have implications for further development. Second, neuropsychological measures available to assess executive functions in children are limited in number and scope and may not be sensitive to the gradual developmental changes. The present article provides an overview of the salient neurodevelopmental stages of executive functioning and discusses the utilization of recently developed neuropsychological measures to assess these stages. Comments on clinical implications of these findings regarding Traumatic Brain Injury will be provided.

FRAGSION: ultra-fast protein fragment library generation by IOHMM sampling.

PubMed

Bhattacharya, Debswapna; Adhikari, Badri; Li, Jilong; Cheng, Jianlin

2016-07-01

Speed, accuracy and robustness of building protein fragment library have important implications in de novo protein structure prediction since fragment-based methods are one of the most successful approaches in template-free modeling (FM). Majority of the existing fragment detection methods rely on database-driven search strategies to identify candidate fragments, which are inherently time-consuming and often hinder the possibility to locate longer fragments due to the limited sizes of databases. Also, it is difficult to alleviate the effect of noisy sequence-based predicted features such as secondary structures on the quality of fragment. Here, we present FRAGSION, a database-free method to efficiently generate protein fragment library by sampling from an Input-Output Hidden Markov Model. FRAGSION offers some unique features compared to existing approaches in that it (i) is lightning-fast, consuming only few seconds of CPU time to generate fragment library for a protein of typical length (300 residues); (ii) can generate dynamic-size fragments of any length (even for the whole protein sequence) and (iii) offers ways to handle noise in predicted secondary structure during fragment sampling. On a FM dataset from the most recent Critical Assessment of Structure Prediction, we demonstrate that FGRAGSION provides advantages over the state-of-the-art fragment picking protocol of ROSETTA suite by speeding up computation by several orders of magnitude while achieving comparable performance in fragment quality. Source code and executable versions of FRAGSION for Linux and MacOS is freely available to non-commercial users at http://sysbio.rnet.missouri.edu/FRAGSION/ It is bundled with a manual and example data. chengji@missouri.edu Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Basis for a neuronal version of Grover's quantum algorithm

PubMed Central

Clark, Kevin B.

2014-01-01

Grover's quantum (search) algorithm exploits principles of quantum information theory and computation to surpass the strong Church–Turing limit governing classical computers. The algorithm initializes a search field into superposed N (eigen)states to later execute nonclassical “subroutines” involving unitary phase shifts of measured states and to produce root-rate or quadratic gain in the algorithmic time (O(N1/2)) needed to find some “target” solution m. Akin to this fast technological search algorithm, single eukaryotic cells, such as differentiated neurons, perform natural quadratic speed-up in the search for appropriate store-operated Ca2+ response regulation of, among other processes, protein and lipid biosynthesis, cell energetics, stress responses, cell fate and death, synaptic plasticity, and immunoprotection. Such speed-up in cellular decision making results from spatiotemporal dynamics of networked intracellular Ca2+-induced Ca2+ release and the search (or signaling) velocity of Ca2+ wave propagation. As chemical processes, such as the duration of Ca2+ mobilization, become rate-limiting over interstore distances, Ca2+ waves quadratically decrease interstore-travel time from slow saltatory to fast continuous gradients proportional to the square-root of the classical Ca2+ diffusion coefficient, D1/2, matching the computing efficiency of Grover's quantum algorithm. In this Hypothesis and Theory article, I elaborate on these traits using a fire-diffuse-fire model of store-operated cytosolic Ca2+ signaling valid for glutamatergic neurons. Salient model features corresponding to Grover's quantum algorithm are parameterized to meet requirements for the Oracle Hadamard transform and Grover's iteration. A neuronal version of Grover's quantum algorithm figures to benefit signal coincidence detection and integration, bidirectional synaptic plasticity, and other vital cell functions by rapidly selecting, ordering, and/or counting optional response regulation choices. PMID:24860419

A Mismatch Between Athlete Practice and Current Sports Nutrition Guidelines Among Elite Female and Male Middle- and Long-Distance Athletes.

PubMed

Heikura, Ida A; Stellingwerff, Trent; Mero, Antti A; Uusitalo, Arja Leena Tuulia; Burke, Louise M

2017-08-01

Contemporary nutrition guidelines promote a variety of periodized and time-sensitive recommendations, but current information regarding the knowledge and practice of these strategies among world-class athletes is limited. The aim of this study was to investigate this theme by implementing a questionnaire on dietary periodization practices in national/international level female (n = 27) and male (n = 21) middle- and long-distance runners/race-walkers. The questionnaire aimed to gain information on between and within-day dietary choices, as well as timing of pre- and posttraining meals and practices of training with low or high carbohydrate (CHO) availability. Data are shown as percentage (%) of all athletes, with differences in responses between subgroups (sex or event) shown as Chi-square x 2 when p < .05. Nearly two-thirds of all athletes reported that they aim to eat more food on, or after, hard training days. Most athletes said they focus on adequate fueling (96%) and adequate CHO and protein (PRO) recovery (87%) around key sessions. Twenty-six percent of athletes (11% of middle vs 42% of long-distance athletes [x 2 (1, n = 46) = 4.308, p = .038, phi = 0.3])) reported to undertake training in the fasted state, while 11% said they periodically restrict CHO intake, with 30% ingesting CHO during training sessions. Our findings show that elite endurance athletes appear to execute pre- and post-key session nutrition recovery recommendations. However, very few athletes deliberately undertake some contemporary dietary periodization approaches, such as training in the fasted state or periodically restricting CHO intake. This study suggests mismatches between athlete practice and current and developing sports nutrition guidelines.

A new and inexpensive non-bit-for-bit solution reproducibility test based on time step convergence (TSC1.0)

DOE PAGES

Wan, Hui; Zhang, Kai; Rasch, Philip J.; ...

2017-02-03

A test procedure is proposed for identifying numerically significant solution changes in evolution equations used in atmospheric models. The test issues a fail signal when any code modifications or computing environment changes lead to solution differences that exceed the known time step sensitivity of the reference model. Initial evidence is provided using the Community Atmosphere Model (CAM) version 5.3 that the proposed procedure can be used to distinguish rounding-level solution changes from impacts of compiler optimization or parameter perturbation, which are known to cause substantial differences in the simulated climate. The test is not exhaustive since it does not detect issues associatedmore » with diagnostic calculations that do not feedback to the model state variables. Nevertheless, it provides a practical and objective way to assess the significance of solution changes. The short simulation length implies low computational cost. The independence between ensemble members allows for parallel execution of all simulations, thus facilitating fast turnaround. The new method is simple to implement since it does not require any code modifications. We expect that the same methodology can be used for any geophysical model to which the concept of time step  convergence is applicable.« less

Pulse shape discrimination of Cs2LiYCl6:Ce3+ detectors at high count rate based on triangular and trapezoidal filters

NASA Astrophysics Data System (ADS)

Wen, Xianfei; Enqvist, Andreas

2017-09-01

Cs2LiYCl6:Ce3+ (CLYC) detectors have demonstrated the capability to simultaneously detect γ-rays and thermal and fast neutrons with medium energy resolution, reasonable detection efficiency, and substantially high pulse shape discrimination performance. A disadvantage of CLYC detectors is the long scintillation decay times, which causes pulse pile-up at moderate input count rate. Pulse processing algorithms were developed based on triangular and trapezoidal filters to discriminate between neutrons and γ-rays at high count rate. The algorithms were first tested using low-rate data. They exhibit a pulse-shape discrimination performance comparable to that of the charge comparison method, at low rate. Then, they were evaluated at high count rate. Neutrons and γ-rays were adequately identified with high throughput at rates of up to 375 kcps. The algorithm developed using the triangular filter exhibits discrimination capability marginally higher than that of the trapezoidal filter based algorithm irrespective of low or high rate. The algorithms exhibit low computational complexity and are executable on an FPGA in real-time. They are also suitable for application to other radiation detectors whose pulses are piled-up at high rate owing to long scintillation decay times.

A combined joint diagonalization-MUSIC algorithm for subsurface targets localization

NASA Astrophysics Data System (ADS)

Wang, Yinlin; Sigman, John B.; Barrowes, Benjamin E.; O'Neill, Kevin; Shubitidze, Fridon

2014-06-01

This paper presents a combined joint diagonalization (JD) and multiple signal classification (MUSIC) algorithm for estimating subsurface objects locations from electromagnetic induction (EMI) sensor data, without solving ill-posed inverse-scattering problems. JD is a numerical technique that finds the common eigenvectors that diagonalize a set of multistatic response (MSR) matrices measured by a time-domain EMI sensor. Eigenvalues from targets of interest (TOI) can be then distinguished automatically from noise-related eigenvalues. Filtering is also carried out in JD to improve the signal-to-noise ratio (SNR) of the data. The MUSIC algorithm utilizes the orthogonality between the signal and noise subspaces in the MSR matrix, which can be separated with information provided by JD. An array of theoreticallycalculated Green's functions are then projected onto the noise subspace, and the location of the target is estimated by the minimum of the projection owing to the orthogonality. This combined method is applied to data from the Time-Domain Electromagnetic Multisensor Towed Array Detection System (TEMTADS). Examples of TEMTADS test stand data and field data collected at Spencer Range, Tennessee are analyzed and presented. Results indicate that due to its noniterative mechanism, the method can be executed fast enough to provide real-time estimation of objects' locations in the field.

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

Blind Seer: A Scalable Private DBMS

DTIC Science & Technology

2014-05-01

searchable index terms per DB row, in time comparable to (insecure) MySQL (many practical queries can be privately executed with work 1.2-3 times slower...than MySQL , although some queries are costlier). We support a rich query set, including searching on arbitrary boolean formulas on keywords and ranges...index terms per DB row, in time comparable to (insecure) MySQL (many practical queries can be privately executed with work 1.2-3 times slower than MySQL

Television and children's executive function.

PubMed

Lillard, Angeline S; Li, Hui; Boguszewski, Katie

2015-01-01

Children spend a lot of time watching television on its many platforms: directly, online, and via videos and DVDs. Many researchers are concerned that some types of television content appear to negatively influence children's executive function. Because (1) executive function predicts key developmental outcomes, (2) executive function appears to be influenced by some television content, and (3) American children watch large quantities of television (including the content of concern), the issues discussed here comprise a crucial public health issue. Further research is needed to reveal exactly what television content is implicated, what underlies television's effect on executive function, how long the effect lasts, and who is affected. © 2015 Elsevier Inc. All rights reserved.

Affordable Electro-Magnetic Interference (EMI) Testing on Large Space Vehicles

NASA Technical Reports Server (NTRS)

Aldridge, Edward; Curry, Bruce; Scully, Robert

2015-01-01

Objective: Perform System-Level EMI testing of the Orion Exploration Flight Test-1 (EFT-1) spacecraft in situ in the Kennedy Space Center's Neil Armstrong Operations & Checkout (O&C) Facility in 6 days. The only way to execute the system-level EMI testing and meet this schedule challenge was to perform the EMI testing in situ in the Final Assembly & System Test (FAST) Cell in a reverberant mode, not the direct illumination mode originally planned. This required the unplanned construction of a Faraday Cage around the vehicle and FAST Cell structure. The presence of massive steel platforms created many challenges to developing an efficient screen room to contain the RF energy and yield an effective reverberant chamber. An initial effectiveness test showed marginal performance, but improvements implemented afterward resulted in the final test performing surprisingly well! The paper will explain the design, the challenges, and the changes that made the difference in performance!

Analysis of nanopore arrangement and structural features of anodic alumina layers formed by two-step anodizing in oxalic acid using the dedicated executable software

NASA Astrophysics Data System (ADS)

Zaraska, Leszek; Stępniowski, Wojciech J.; Sulka, Grzegorz D.; Ciepiela, Eryk; Jaskuła, Marian

2014-02-01

Anodic porous alumina layers were fabricated by a two-step self-organized anodization in 0.3 M oxalic acid under various anodizing potentials ranging from 30 to 60 V at two different temperatures (10 and 17 ∘C). The effect of anodizing conditions on structural features and pore arrangement of AAO was investigated in detail by using the dedicated executable publication combined with ImageJ software. With increasing anodizing potential, a linear increase of the average pore diameter, interpore distance, wall thickness and barrier layer thickness, as well as a decrease of the pore density, were observed. In addition, the higher pore diameter and porosity values were obtained for samples anodized at the elevated temperature, independently of the anodizing potential. A degree of pore order was investigated on the basis of Delaunay triangulations (defect maps) and calculation of pair distribution or angle distribution functions (PDF or ADF), respectively. All methods confirmed that in order to obtain nanoporous alumina with the best, hexagonal pore arrangement, the potential of 40 V should be applied during anodization. It was confirmed that the dedicated executable publication can be used to a fast and complex analysis of nanopore arrangement and structural features of nanoporous oxide layers.

Attention and memory evaluation across the life span: heterogeneous effects of age and education.

PubMed

Gómez-Pérez, Esther; Ostrosky-Solís, Feggy

2006-05-01

The developmental sequences of attention and memory were studied by utilizing normative data derived from the neuropsychological battery named NEUROPSI ATTENTION AND MEMORY. A sample of 521 Spanish-speaking individuals, aged 6 to 85 years, participated in this study. In the adult sample, educational level ranged from 0 to 22 years of education. Data from subtests measuring orientation, attention and concentration, executive functions, working memory, immediate and delayed verbal memory, and immediate and delayed visual memory were included. The factor structure of the analyzed battery is presented. The effects of age and education on this structure were analyzed. Results suggested that although attention and memory are related, their developmental sequences are separated from one another. During childhood, the development of selective and sustained attention, attentional-working memory, and executive functions showed a fast improvement in performance. Development of verbal memory and place and person orientation showed a slower increment in scores. In the adult sample it was found that factors related to memory are sensitive to age, whereas those related to attention and executive functions are sensitive to education. The consideration of both the developmental sequence, as well as differential effects of education, can improve the sensitivity and specificity of neuropsychological measures, allowing early diagnosis of cognitive dysfunction and implementation of adequate rehabilitation programs.

A virtual data language and system for scientific workflow management in data grid environments

NASA Astrophysics Data System (ADS)

Zhao, Yong

With advances in scientific instrumentation and simulation, scientific data is growing fast in both size and analysis complexity. So-called Data Grids aim to provide high performance, distributed data analysis infrastructure for data- intensive sciences, where scientists distributed worldwide need to extract information from large collections of data, and to share both data products and the resources needed to produce and store them. However, the description, composition, and execution of even logically simple scientific workflows are often complicated by the need to deal with "messy" issues like heterogeneous storage formats and ad-hoc file system structures. We show how these difficulties can be overcome via a typed workflow notation called virtual data language, within which issues of physical representation are cleanly separated from logical typing, and by the implementation of this notation within the context of a powerful virtual data system that supports distributed execution. The resulting language and system are capable of expressing complex workflows in a simple compact form, enacting those workflows in distributed environments, monitoring and recording the execution processes, and tracing the derivation history of data products. We describe the motivation, design, implementation, and evaluation of the virtual data language and system, and the application of the virtual data paradigm in various science disciplines, including astronomy, cognitive neuroscience.

Efficient Irregular Wavefront Propagation Algorithms on Hybrid CPU-GPU Machines

PubMed Central

Teodoro, George; Pan, Tony; Kurc, Tahsin; Kong, Jun; Cooper, Lee; Saltz, Joel

2013-01-01

We address the problem of efficient execution of a computation pattern, referred to here as the irregular wavefront propagation pattern (IWPP), on hybrid systems with multiple CPUs and GPUs. The IWPP is common in several image processing operations. In the IWPP, data elements in the wavefront propagate waves to their neighboring elements on a grid if a propagation condition is satisfied. Elements receiving the propagated waves become part of the wavefront. This pattern results in irregular data accesses and computations. We develop and evaluate strategies for efficient computation and propagation of wavefronts using a multi-level queue structure. This queue structure improves the utilization of fast memories in a GPU and reduces synchronization overheads. We also develop a tile-based parallelization strategy to support execution on multiple CPUs and GPUs. We evaluate our approaches on a state-of-the-art GPU accelerated machine (equipped with 3 GPUs and 2 multicore CPUs) using the IWPP implementations of two widely used image processing operations: morphological reconstruction and euclidean distance transform. Our results show significant performance improvements on GPUs. The use of multiple CPUs and GPUs cooperatively attains speedups of 50× and 85× with respect to single core CPU executions for morphological reconstruction and euclidean distance transform, respectively. PMID:23908562

An Automatic Prediction of Epileptic Seizures Using Cloud Computing and Wireless Sensor Networks.

PubMed

Sareen, Sanjay; Sood, Sandeep K; Gupta, Sunil Kumar

2016-11-01

Epilepsy is one of the most common neurological disorders which is characterized by the spontaneous and unforeseeable occurrence of seizures. An automatic prediction of seizure can protect the patients from accidents and save their life. In this article, we proposed a mobile-based framework that automatically predict seizures using the information contained in electroencephalography (EEG) signals. The wireless sensor technology is used to capture the EEG signals of patients. The cloud-based services are used to collect and analyze the EEG data from the patient's mobile phone. The features from the EEG signal are extracted using the fast Walsh-Hadamard transform (FWHT). The Higher Order Spectral Analysis (HOSA) is applied to FWHT coefficients in order to select the features set relevant to normal, preictal and ictal states of seizure. We subsequently exploit the selected features as input to a k-means classifier to detect epileptic seizure states in a reasonable time. The performance of the proposed model is tested on Amazon EC2 cloud and compared in terms of execution time and accuracy. The findings show that with selected HOS based features, we were able to achieve a classification accuracy of 94.6 %.

Centroid stabilization in alignment of FOA corner cube: designing of a matched filter

NASA Astrophysics Data System (ADS)

Awwal, Abdul; Wilhelmsen, Karl; Roberts, Randy; Leach, Richard; Miller Kamm, Victoria; Ngo, Tony; Lowe-Webb, Roger

2015-02-01

The current automation of image-based alignment of NIF high energy laser beams is providing the capability of executing multiple target shots per day. An important aspect of performing multiple shots in a day is to reduce additional time spent aligning specific beams due to perturbations in those beam images. One such alignment is beam centration through the second and third harmonic generating crystals in the final optics assembly (FOA), which employs two retro-reflecting corner cubes to represent the beam center. The FOA houses the frequency conversion crystals for third harmonic generation as the beams enters the target chamber. Beam-to-beam variations and systematic beam changes over time in the FOA corner-cube images can lead to a reduction in accuracy as well as increased convergence durations for the template based centroid detector. This work presents a systematic approach of maintaining FOA corner cube centroid templates so that stable position estimation is applied thereby leading to fast convergence of alignment control loops. In the matched filtering approach, a template is designed based on most recent images taken in the last 60 days. The results show that new filter reduces the divergence of the position estimation of FOA images.

Preconditioning 2D Integer Data for Fast Convex Hull Computations.

PubMed

Cadenas, José Oswaldo; Megson, Graham M; Luengo Hendriks, Cris L

2016-01-01

In order to accelerate computing the convex hull on a set of n points, a heuristic procedure is often applied to reduce the number of points to a set of s points, s ≤ n, which also contains the same hull. We present an algorithm to precondition 2D data with integer coordinates bounded by a box of size p × q before building a 2D convex hull, with three distinct advantages. First, we prove that under the condition min(p, q) ≤ n the algorithm executes in time within O(n); second, no explicit sorting of data is required; and third, the reduced set of s points forms a simple polygonal chain and thus can be directly pipelined into an O(n) time convex hull algorithm. This paper empirically evaluates and quantifies the speed up gained by preconditioning a set of points by a method based on the proposed algorithm before using common convex hull algorithms to build the final hull. A speedup factor of at least four is consistently found from experiments on various datasets when the condition min(p, q) ≤ n holds; the smaller the ratio min(p, q)/n is in the dataset, the greater the speedup factor achieved.

Motor Variability Arises from a Slow Random Walk in Neural State

PubMed Central

Chaisanguanthum, Kris S.; Shen, Helen H.

2014-01-01

Even well practiced movements cannot be repeated without variability. This variability is thought to reflect “noise” in movement preparation or execution. However, we show that, for both professional baseball pitchers and macaque monkeys making reaching movements, motor variability can be decomposed into two statistical components, a slowly drifting mean and fast trial-by-trial fluctuations about the mean. The preparatory activity of dorsal premotor cortex/primary motor cortex neurons in monkey exhibits similar statistics. Although the neural and behavioral drifts appear to be correlated, neural activity does not account for trial-by-trial fluctuations in movement, which must arise elsewhere, likely downstream. The statistics of this drift are well modeled by a double-exponential autocorrelation function, with time constants similar across the neural and behavioral drifts in two monkeys, as well as the drifts observed in baseball pitching. These time constants can be explained by an error-corrective learning processes and agree with learning rates measured directly in previous experiments. Together, these results suggest that the central contributions to movement variability are not simply trial-by-trial fluctuations but are rather the result of longer-timescale processes that may arise from motor learning. PMID:25186752

Change Detection Algorithms for Surveillance in Visual IoT: A Comparative Study

NASA Astrophysics Data System (ADS)

Akram, Beenish Ayesha; Zafar, Amna; Akbar, Ali Hammad; Wajid, Bilal; Chaudhry, Shafique Ahmad

2018-01-01

The VIoT (Visual Internet of Things) connects virtual information world with real world objects using sensors and pervasive computing. For video surveillance in VIoT, ChD (Change Detection) is a critical component. ChD algorithms identify regions of change in multiple images of the same scene recorded at different time intervals for video surveillance. This paper presents performance comparison of histogram thresholding and classification ChD algorithms using quantitative measures for video surveillance in VIoT based on salient features of datasets. The thresholding algorithms Otsu, Kapur, Rosin and classification methods k-means, EM (Expectation Maximization) were simulated in MATLAB using diverse datasets. For performance evaluation, the quantitative measures used include OSR (Overall Success Rate), YC (Yule's Coefficient) and JC (Jaccard's Coefficient), execution time and memory consumption. Experimental results showed that Kapur's algorithm performed better for both indoor and outdoor environments with illumination changes, shadowing and medium to fast moving objects. However, it reflected degraded performance for small object size with minor changes. Otsu algorithm showed better results for indoor environments with slow to medium changes and nomadic object mobility. k-means showed good results in indoor environment with small object size producing slow change, no shadowing and scarce illumination changes.

Real-Time Data Processing in the muon system of the D0 detector.

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

Neeti Parashar et al.

2001-07-03

This paper presents a real-time application of the 16-bit fixed point Digital Signal Processors (DSPs), in the Muon System of the D0 detector located at the Fermilab Tevatron, presently the world's highest-energy hadron collider. As part of the Upgrade for a run beginning in the year 2000, the system is required to process data at an input event rate of 10 KHz without incurring significant deadtime in readout. The ADSP21csp01 processor has high I/O bandwidth, single cycle instruction execution and fast task switching support to provide efficient multisignal processing. The processor's internal memory consists of 4K words of Program Memorymore » and 4K words of Data Memory. In addition there is an external memory of 32K words for general event buffering and 16K words of Dual port Memory for input data queuing. This DSP fulfills the requirement of the Muon subdetector systems for data readout. All error handling, buffering, formatting and transferring of the data to the various trigger levels of the data acquisition system is done in software. The algorithms developed for the system complete these tasks in about 20 {micro}s per event.« less

Differential and relaxed image foresting transform for graph-cut segmentation of multiple 3D objects.

PubMed

Moya, Nikolas; Falcão, Alexandre X; Ciesielski, Krzysztof C; Udupa, Jayaram K

2014-01-01

Graph-cut algorithms have been extensively investigated for interactive binary segmentation, when the simultaneous delineation of multiple objects can save considerable user's time. We present an algorithm (named DRIFT) for 3D multiple object segmentation based on seed voxels and Differential Image Foresting Transforms (DIFTs) with relaxation. DRIFT stands behind efficient implementations of some state-of-the-art methods. The user can add/remove markers (seed voxels) along a sequence of executions of the DRIFT algorithm to improve segmentation. Its first execution takes linear time with the image's size, while the subsequent executions for corrections take sublinear time in practice. At each execution, DRIFT first runs the DIFT algorithm, then it applies diffusion filtering to smooth boundaries between objects (and background) and, finally, it corrects possible objects' disconnection occurrences with respect to their seeds. We evaluate DRIFT in 3D CT-images of the thorax for segmenting the arterial system, esophagus, left pleural cavity, right pleural cavity, trachea and bronchi, and the venous system.

Representation and Analysis of Real-Time Control Structures.

DTIC Science & Technology

1980-08-01

external processes which cannot be forced to cooperate with programmed processes through use of a synchronization primitive such as a semaphore [Dijkstre...amounts to each task, but the time slices are synchronized with program execution. The length of the codestrip is determined by the response time...which might be synchronous or asynchronous with respect to the executing task. The notation can represent total and partial orderings among its tasks, and

Mechanical analysis of the roundhouse kick according to height and distance in taekwondo.

PubMed

Estevan, I; Falco, C

2013-12-01

Competition regulation in taekwondo has experienced several changes during the last few years, for example, kicks to the head score more points than kicks to the chest. In addition, some external factors such as the height of target and execution distance seem to affect the kick performance. The aim of this study was to analyse selected biomechanical parameters (impact force, reaction time, and execution time) according to the height and execution distance in two different male groups (experts (n = 12) and novices (n = 21)). Athletes kicked twice from every execution distance (short, normal and long) and towards two different heights of target (chest and head) in a random order. Novices kicked to the head with a longer reaction time than to the chest (p < 0.05) but experts were able to kick with similar performance for both heights. From short and normal distances experts kicked with similar performance; whereas from the normal distance novices had longer reaction and execution time than from the short distance (p < 0.05). In conclusion, in counterattacking situations, experts should perform the roundhouse kick to the head instead of to the chest, because it produces better scores with similar performance; whereas novice athletes should avoid kicking to the head because they are not able to kick with similar performance. Moreover, it is recommended that during counterattacks higher-level taekwondo athletes should intend to kick from normal distances.

MECHANICAL ANALYSIS OF THE ROUNDHOUSE KICK ACCORDING TO HEIGHT AND DISTANCE IN TAEKWONDO

PubMed Central

Falco, C.

2013-01-01

Competition regulation in taekwondo has experienced several changes during the last few years, for example, kicks to the head score more points than kicks to the chest. In addition, some external factors such as the height of target and execution distance seem to affect the kick performance. The aim of this study was to analyse selected biomechanical parameters (impact force, reaction time, and execution time) according to the height and execution distance in two different male groups (experts (n = 12) and novices (n = 21)). Athletes kicked twice from every execution distance (short, normal and long) and towards two different heights of target (chest and head) in a random order. Novices kicked to the head with a longer reaction time than to the chest (p < 0.05) but experts were able to kick with similar performance for both heights. From short and normal distances experts kicked with similar performance; whereas from the normal distance novices had longer reaction and execution time than from the short distance (p < 0.05). In conclusion, in counterattacking situations, experts should perform the roundhouse kick to the head instead of to the chest, because it produces better scores with similar performance; whereas novice athletes should avoid kicking to the head because they are not able to kick with similar performance. Moreover, it is recommended that during counterattacks higher-level taekwondo athletes should intend to kick from normal distances. PMID:24744499

Performance Analysis of Polymorphous Computing Architectures

DTIC Science & Technology

2001-01-01

G H F Proc 5 : 4 : 3 11 1 Figure 3. Self-timed execution. D C B F G H E D B H EA CG...F D C B F G H E D B H EA CG F AProc 1 Proc 2 Proc 3 Proc 4 Proc 5 185 cution pattern when the application graph in Figure 2 is executed in a self...transform, a quadra- E Figure 10. Self-timed execution with first-iteration actors denoted by T. D B H E CG F D C B F G H E D B H EA CG F A 18 T T T

Preoperative fasting for elective surgery in a regional hospital in Oman.

PubMed

Abdullah Al Maqbali, Mohammed

2016-07-28

A fasting period before anesthesia is necessary to avoid the aspiration of stomach contents, which can be threatening to the patient's life. Guidelines from professional societies in the USA and UK recommend that healthy patients fast for 6 hours from solid food and 2 hours from liquids. Despite this, many institutions still practice nil-by-mouth after midnight. This can affect the patient's recovery after surgery, and increase the length of stay in hospital. The aim of this study was to assess the duration of fasting before elective surgery on the part of adult patients. A prospective study was conducted to identify the fasting time and complications among surgical patients undergoing elective surgery over a 4-month period. The patients were asked for preoperative fasting times, and the complication. The demographic data were taken from the patients' files. A total of 169 patients were included in the study, 88 male and 81 female. The minimum and maximum fasting hours with regard to food were 7 hours and 19 hours, respectively; all the patients fasted from food for longer than the recommended time. The minimum and maximum fasting hours for fluids were 4 hours and 19 hours, respectively; all the patients fasted from fluid for longer than the recommended time. Most of the patients fasted from food and fluids for more than the time recommended by the American Society of Anaesthesiologists, the Royal College of Nursing, the Association of Anaesthetists of Great Britain and Ireland and the Royal College of Anaesthetists. Excessive fasting could lead to discomfort and possible morbidity in surgical patients. The surgical team needs to collaborate to reduce the fasting time by revising the operative list.

Circadian Rhythms in Executive Function during the Transition to Adolescence: The Effect of Synchrony between Chronotype and Time of Day

ERIC Educational Resources Information Center

Hahn, Constanze; Cowell, Jason M.; Wiprzycka, Ursula J.; Goldstein, David; Ralph, Martin; Hasher, Lynn; Zelazo, Philip David

2012-01-01

To explore the influence of circadian rhythms on executive function during early adolescence, we administered a battery of executive function measures (including a Go-Nogo task, the Iowa Gambling Task, a Self-ordered Pointing task, and an Intra/Extradimensional Shift task) to Morning-preference and Evening-preference participants (N = 80) between…

The Touche Ross Survey of Business Executives on Non-Profit Boards. An Opinion Study Based on Interviews with 309 Business Executives.

ERIC Educational Resources Information Center

Research and Forecasts, Inc., New York, NY.

Three hundred eight business executives from boards of nonprofit educational, social service, or cultural organizations were surveyed for their opinions on their roles. It was found that a single overriding concern is the ever-increasing demand for commitment and accountability. This is reflected particularly in three issues: time, money, and…

Developing an effective business plan.

PubMed

Lehman, L B

1996-06-01

At some time, virtually all managed care executives, and most physician executives, will be asked to develop business plans. Business plans are thoughtful, comprehensive, and realistic descriptions of the many aspects of the formulation of a new business product or line for market. The author describes what goes into the writing of a business plan and how the physician executive should approach this task.

Data preprocessing for determining outer/inner parallelization in the nested loop problem using OpenMP

NASA Astrophysics Data System (ADS)

Handhika, T.; Bustamam, A.; Ernastuti, Kerami, D.

2017-07-01

Multi-thread programming using OpenMP on the shared-memory architecture with hyperthreading technology allows the resource to be accessed by multiple processors simultaneously. Each processor can execute more than one thread for a certain period of time. However, its speedup depends on the ability of the processor to execute threads in limited quantities, especially the sequential algorithm which contains a nested loop. The number of the outer loop iterations is greater than the maximum number of threads that can be executed by a processor. The thread distribution technique that had been found previously only be applied by the high-level programmer. This paper generates a parallelization procedure for low-level programmer in dealing with 2-level nested loop problems with the maximum number of threads that can be executed by a processor is smaller than the number of the outer loop iterations. Data preprocessing which is related to the number of the outer loop and the inner loop iterations, the computational time required to execute each iteration and the maximum number of threads that can be executed by a processor are used as a strategy to determine which parallel region that will produce optimal speedup.

The risk of shorter fasting time for pediatric deep sedation.

PubMed

Clark, Mathew; Birisci, Esma; Anderson, Jordan E; Anliker, Christina M; Bryant, Micheal A; Downs, Craig; Dalabih, Abdallah

2016-01-01

Current guidelines adopted by the American Academy of Pediatrics calls for prolonged fasting times before performing pediatric procedural sedation and analgesia (PSA). PSA is increasingly provided to children outside of the operating theater by sedation trained pediatric providers and does not require airway manipulation. We investigated the safety of a shorter fasting time compared to a longer and guideline compliant fasting time. We tried to identify the association between fasting time and sedation-related complications. This is a prospective observational study that included children 2 months to 18 years of age and had an American Society of Anesthesiologists physical status classification of I or II, who underwent deep sedation for elective procedures, performed by pediatric critical care providers. Procedures included radiologic imaging studies, electroencephalograms, auditory brainstem response, echocardiograms, Botox injections, and other minor surgical procedures. Subjects were divided into two groups depending on the length of their fasting time (4-6 h and >6 h). Complication rates were calculated and compared between the three groups. In the studied group of 2487 subjects, 1007 (40.5%) had fasting time of 4-6 h and the remaining 1480 (59.5%) subjects had fasted for >6 h. There were no statistically significant differences in any of the studied complications between the two groups. This study found no difference in complication rate in regard to the fasting time among our subjects cohort, which included only healthy children receiving elective procedures performed by sedation trained pediatric critical care providers. This suggests that using shorter fasting time may be safe for procedures performed outside of the operating theater that does not involve high-risk patients or airway manipulation.

Beauty and the beast: Some perspectives on efficient model analysis, surrogate models, and the future of modeling

NASA Astrophysics Data System (ADS)

Hill, M. C.; Jakeman, J.; Razavi, S.; Tolson, B.

2015-12-01

For many environmental systems model runtimes have remained very long as more capable computers have been used to add more processes and more time and space discretization. Scientists have also added more parameters and kinds of observations, and many model runs are needed to explore the models. Computational demand equals run time multiplied by number of model runs divided by parallelization opportunities. Model exploration is conducted using sensitivity analysis, optimization, and uncertainty quantification. Sensitivity analysis is used to reveal consequences of what may be very complex simulated relations, optimization is used to identify parameter values that fit the data best, or at least better, and uncertainty quantification is used to evaluate the precision of simulated results. The long execution times make such analyses a challenge. Methods for addressing this challenges include computationally frugal analysis of the demanding original model and a number of ingenious surrogate modeling methods. Both commonly use about 50-100 runs of the demanding original model. In this talk we consider the tradeoffs between (1) original model development decisions, (2) computationally frugal analysis of the original model, and (3) using many model runs of the fast surrogate model. Some questions of interest are as follows. If the added processes and discretization invested in (1) are compared with the restrictions and approximations in model analysis produced by long model execution times, is there a net benefit related of the goals of the model? Are there changes to the numerical methods that could reduce the computational demands while giving up less fidelity than is compromised by using computationally frugal methods or surrogate models for model analysis? Both the computationally frugal methods and surrogate models require that the solution of interest be a smooth function of the parameters or interest. How does the information obtained from the local methods typical of (2) and the global averaged methods typical of (3) compare for typical systems? The discussion will use examples of response of the Greenland glacier to global warming and surface and groundwater modeling.

Varying execution discipline to increase performance

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

Campbell, P.L.; Maccabe, A.B.

1993-12-22

This research investigates the relationship between execution discipline and performance. The hypothesis has two parts: 1. Different execution disciplines exhibit different performance for different computations, and 2. These differences can be effectively predicted by heuristics. A machine model is developed that can vary its execution discipline. That is, the model can execute a given program using either the control-driven, data-driven or demand-driven execution discipline. This model is referred to as a ``variable-execution-discipline`` machine. The instruction set for the model is the Program Dependence Web (PDW). The first part of the hypothesis will be tested by simulating the execution of themore » machine model on a suite of computations, based on the Livermore Fortran Kernel (LFK) Test (a.k.a. the Livermore Loops), using all three execution disciplines. Heuristics are developed to predict relative performance. These heuristics predict (a) the execution time under each discipline for one iteration of each loop and (b) the number of iterations taken by that loop; then the heuristics use those predictions to develop a prediction for the execution of the entire loop. Similar calculations are performed for branch statements. The second part of the hypothesis will be tested by comparing the results of the simulated execution with the predictions produced by the heuristics. If the hypothesis is supported, then the door is open for the development of machines that can vary execution discipline to increase performance.« less

76 FR 71092 - Self-Regulatory Organizations; Chicago Board Options Exchange, Incorporated; Notice of Filing of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-16

... quoted prices in the respective SPX series at the time of execution, each constituent execution will be... Demeterfi, Emanuel Derman, Michael Kamal and Joseph Zou, Goldman Sachs Quantitative Strategies Research... series. The following table shows the SPX option mid-quote prices prevailing at the time of the S&P 500...

Effects of Age, Intelligence and Executive Control Function on Saccadic Reaction Time in Persons with Intellectual Disabilities

ERIC Educational Resources Information Center

Haishi, Koichi; Okuzumi, Hideyuki; Kokubun, Mitsuru

2011-01-01

The current research aimed to clarify the influence of age, intelligence and executive control function on the central tendency and intraindividual variability of saccadic reaction time in persons with intellectual disabilities. Participants were 44 persons with intellectual disabilities aged between 13 and 57 years whose IQs were between 14 and…

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.

Preoperative fasting times in elective surgical patients at a referral Hospital in Botswana.

PubMed

Abebe, Worknehe Agegnehu; Rukewe, Ambrose; Bekele, Negussie Alula; Stoffel, Moeng; Dichabeng, Mompelegi Nicoh; Shifa, Jemal Zeberga

2016-01-01

Adults and children are required to fast before anaesthesia to reduce the risk of regurgitation and aspiration of gastric contents. However, prolonged periods of fasting are unnecessary and may cause complications. This study was conducted to evaluate preoperative fasting period in our centre and compare it with the ASA recommendations and factors that influence fasting periods. This is a cross-sectional study of preoperative fasting times among elective surgical patients. A total numbers of 260 patients were interviewed as they arrived at the reception area of operating theatre using questionnaire. Majority of patients (98.1%) were instructed to fast from midnight. Fifteen patients (5.8%) reported that they were told the importance of preoperative fasting. The mean fasting period were 15.9±2.5 h (range 12.0-25.3 h) for solids and 15.3±2.3 h (range 12.0-22.0 h) for liquids. The mean duration of fasting was significantly longer for patients operated after midday compared to those operated before midday, p<0.001. The mean fasting periods were 7.65 times longer for clear liquid and 2.5 times for solids than the ASA guidelines. It is imperative that the Hospital should establish Preoperative fasting policies and teach the staff who should ensure compliance with guidelines.

META-GLARE: a shell for CIG systems.

PubMed

Bottrighi, Alessio; Rubrichi, Stefania; Terenziani, Paolo

2015-01-01

In the last twenty years, many different approaches to deal with Computer-Interpretable clinical Guidelines (CIGs) have been developed, each one proposing its own representation formalism (mostly based on the Task-Network Model) execution engine. We propose META-GLARE a shell for easily defining new CIG systems. Using META-GLARE, CIG system designers can easily define their own systems (basically by defining their representation language), with a minimal programming effort. META-GLARE is thus a flexible and powerful vehicle for research about CIGs, since it supports easy and fast prototyping of new CIG systems.

Bit-parallel arithmetic in a massively-parallel associative processor

NASA Technical Reports Server (NTRS)

Scherson, Isaac D.; Kramer, David A.; Alleyne, Brian D.

1992-01-01

A simple but powerful new architecture based on a classical associative processor model is presented. Algorithms for performing the four basic arithmetic operations both for integer and floating point operands are described. For m-bit operands, the proposed architecture makes it possible to execute complex operations in O(m) cycles as opposed to O(m exp 2) for bit-serial machines. A word-parallel, bit-parallel, massively-parallel computing system can be constructed using this architecture with VLSI technology. The operation of this system is demonstrated for the fast Fourier transform and matrix multiplication.

Model-based engineering for medical-device software.

PubMed

Ray, Arnab; Jetley, Raoul; Jones, Paul L; Zhang, Yi

2010-01-01

This paper demonstrates the benefits of adopting model-based design techniques for engineering medical device software. By using a patient-controlled analgesic (PCA) infusion pump as a candidate medical device, the authors show how using models to capture design information allows for i) fast and efficient construction of executable device prototypes ii) creation of a standard, reusable baseline software architecture for a particular device family, iii) formal verification of the design against safety requirements, and iv) creation of a safety framework that reduces verification costs for future versions of the device software. 1.

Simulation of Needle-Type Corona Electrodes by the Finite Element Method

NASA Astrophysics Data System (ADS)

Yang, Shiyou; José Márcio, Machado; Nancy Mieko, Abe; Angelo, Passaro

2007-12-01

This paper describes a software tool, called LEVSOFT, suitable for the electric field simulations of corona electrodes by the Finite Element Method (FEM). Special attention was paid to the user friendly construction of geometries with corners and sharp points, and to the fast generation of highly refined triangular meshes and field maps. The execution of self-adaptive meshes was also implemented. These customized features make the code attractive for the simulation of needle-type corona electrodes. Some case examples involving needle type electrodes are presented.

Executive Function, Survival, and Hospitalization in Chronic Obstructive Pulmonary Disease. A Longitudinal Analysis of the National Emphysema Treatment Trial (NETT)

PubMed Central

Dodd, James W.; Novotny, Paul; Sciurba, Frank C.

2015-01-01

Rationale: Cognitive dysfunction has been demonstrated in chronic obstructive pulmonary disease (COPD), but studies are limited to cross-sectional analyses or incompletely characterized populations. Objectives: We examined longitudinal changes in sensitive measures of executive function in a well-characterized population of patients with severe COPD. Methods: This study was performed on patients enrolled in the National Emphysema Treatment Trial. To assess executive function, we analyzed trail making (TM) A and B times at enrollment in the trial (2,128 patients), and at 12 (731 patients) and 24 months (593 patients) after enrollment, adjusted for surgery, marriage status, age, education, income, depression, PaO2, PaCO2, and smoking. Associations with survival and hospitalizations were examined using Cox regression and linear regression models. Measurements and Main Results: The average age of the patients was 66.4 years, and the average FEV1 was 23.9% predicted. At the time of enrolment, 38% had executive dysfunction. Compared with those who did not, these patients were older, less educated, had higher oxygen use, higher PaCO2, worse quality of life as measured by the St. George’s Respiratory Quotient, reduced well-being, and lower social function. There was no significant change over 2 years in TM A or B times after adjustment for covariables. Changes in TM B times were modestly associated with survival, but changes in TM B − A times were not. Changes in TM scores were not associated with frequency of hospitalization. Lung function, PaO2, smoking, survival, and hospitalizations were not significantly different in those with executive dysfunction. Conclusions: In this large population of patients with severe emphysema and heavy cigarette smoking exposure, there was no significant decline over 2 years in cognitive executive function as measured by TM tests. There was no association between executive function impairment and frequency of hospitalization, and there was a possible modest association with survival. It is plausible that cerebrovascular comorbidities explain previously described cognitive pathology in COPD. PMID:26288391

Specific Features of Executive Dysfunction in Alzheimer-Type Mild Dementia Based on Computerized Cambridge Neuropsychological Test Automated Battery (CANTAB) Test Results.

PubMed

Kuzmickienė, Jurgita; Kaubrys, Gintaras

2016-10-08

BACKGROUND The primary manifestation of Alzheimer's disease (AD) is decline in memory. Dysexecutive symptoms have tremendous impact on functional activities and quality of life. Data regarding frontal-executive dysfunction in mild AD are controversial. The aim of this study was to assess the presence and specific features of executive dysfunction in mild AD based on Cambridge Neuropsychological Test Automated Battery (CANTAB) results. MATERIAL AND METHODS Fifty newly diagnosed, treatment-naïve, mild, late-onset AD patients (MMSE ≥20, AD group) and 25 control subjects (CG group) were recruited in this prospective, cross-sectional study. The CANTAB tests CRT, SOC, PAL, SWM were used for in-depth cognitive assessment. Comparisons were performed using the t test or Mann-Whitney U test, as appropriate. Correlations were evaluated by Pearson r or Spearman R. Statistical significance was set at p<0.05. RESULTS AD and CG groups did not differ according to age, education, gender, or depression. Few differences were found between groups in the SOC test for performance measures: Mean moves (minimum 3 moves): AD (Rank Sum=2227), CG (Rank Sum=623), p<0.001. However, all SOC test time measures differed significantly between groups: SOC Mean subsequent thinking time (4 moves): AD (Rank Sum=2406), CG (Rank Sum=444), p<0.001. Correlations were weak between executive function (SOC) and episodic/working memory (PAL, SWM) (R=0.01-0.38) or attention/psychomotor speed (CRT) (R=0.02-0.37). CONCLUSIONS Frontal-executive functions are impaired in mild AD patients. Executive dysfunction is highly prominent in time measures, but minimal in performance measures. Executive disorders do not correlate with a decline in episodic and working memory or psychomotor speed in mild AD.

Spaceborne computer executive routine functional design specification. Volume 1: Functional design of a flight computer executive program for the reusable shuttle

NASA Technical Reports Server (NTRS)

Curran, R. T.

1971-01-01

A flight computer functional executive design for the reusable shuttle is presented. The design is given in the form of functional flowcharts and prose description. Techniques utilized in the regulation of process flow to accomplish activation, resource allocation, suspension, termination, and error masking based on process primitives are considered. Preliminary estimates of main storage utilization by the Executive are furnished. Conclusions and recommendations for timely, effective software-hardware integration in the reusable shuttle avionics system are proposed.

SU-D-206-02: Evaluation of Partial Storage of the System Matrix for Cone Beam Computed Tomography Using a GPU Platform

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

Matenine, D; Cote, G; Mascolo-Fortin, J

2016-06-15

Purpose: Iterative reconstruction algorithms in computed tomography (CT) require a fast method for computing the intersections between the photons’ trajectories and the object, also called ray-tracing or system matrix computation. This work evaluates different ways to store the system matrix, aiming to reconstruct dense image grids in reasonable time. Methods: We propose an optimized implementation of the Siddon’s algorithm using graphics processing units (GPUs) with a novel data storage scheme. The algorithm computes a part of the system matrix on demand, typically, for one projection angle. The proposed method was enhanced with accelerating options: storage of larger subsets of themore » system matrix, systematic reuse of data via geometric symmetries, an arithmetic-rich parallel code and code configuration via machine learning. It was tested on geometries mimicking a cone beam CT acquisition of a human head. To realistically assess the execution time, the ray-tracing routines were integrated into a regularized Poisson-based reconstruction algorithm. The proposed scheme was also compared to a different approach, where the system matrix is fully pre-computed and loaded at reconstruction time. Results: Fast ray-tracing of realistic acquisition geometries, which often lack spatial symmetry properties, was enabled via the proposed method. Ray-tracing interleaved with projection and backprojection operations required significant additional time. In most cases, ray-tracing was shown to use about 66 % of the total reconstruction time. In absolute terms, tracing times varied from 3.6 s to 7.5 min, depending on the problem size. The presence of geometrical symmetries allowed for non-negligible ray-tracing and reconstruction time reduction. Arithmetic-rich parallel code and machine learning permitted a modest reconstruction time reduction, in the order of 1 %. Conclusion: Partial system matrix storage permitted the reconstruction of higher 3D image grid sizes and larger projection datasets at the cost of additional time, when compared to the fully pre-computed approach. This work was supported in part by the Fonds de recherche du Quebec - Nature et technologies (FRQ-NT). The authors acknowledge partial support by the CREATE Medical Physics Research Training Network grant of the Natural Sciences and Engineering Research Council of Canada (Grant No. 432290).« less

Understanding and Mitigating Protests of Department of Defense Acquisition Contracts

DTIC Science & Technology

2010-08-01

of delivery time that can lock out a rejected offeror from a market . Sixth, more complex contracts, like services versus products , generate more...The engineers, attorneys, or head of a business unit need to explain to the team that spent time working on a bid why the company lost. Executives...agency executives have to explain to their team, who also spent time working on the source solicitation, evaluation, and selection, why the company

Block-Parallel Data Analysis with DIY2

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

Morozov, Dmitriy; Peterka, Tom

DIY2 is a programming model and runtime for block-parallel analytics on distributed-memory machines. Its main abstraction is block-structured data parallelism: data are decomposed into blocks; blocks are assigned to processing elements (processes or threads); computation is described as iterations over these blocks, and communication between blocks is defined by reusable patterns. By expressing computation in this general form, the DIY2 runtime is free to optimize the movement of blocks between slow and fast memories (disk and flash vs. DRAM) and to concurrently execute blocks residing in memory with multiple threads. This enables the same program to execute in-core, out-of-core, serial,more » parallel, single-threaded, multithreaded, or combinations thereof. This paper describes the implementation of the main features of the DIY2 programming model and optimizations to improve performance. DIY2 is evaluated on benchmark test cases to establish baseline performance for several common patterns and on larger complete analysis codes running on large-scale HPC machines.« less

Accelerated gradient based diffuse optical tomographic image reconstruction.

PubMed

Biswas, Samir Kumar; Rajan, K; Vasu, R M

2011-01-01

Fast reconstruction of interior optical parameter distribution using a new approach called Broyden-based model iterative image reconstruction (BMOBIIR) and adjoint Broyden-based MOBIIR (ABMOBIIR) of a tissue and a tissue mimicking phantom from boundary measurement data in diffuse optical tomography (DOT). DOT is a nonlinear and ill-posed inverse problem. Newton-based MOBIIR algorithm, which is generally used, requires repeated evaluation of the Jacobian which consumes bulk of the computation time for reconstruction. In this study, we propose a Broyden approach-based accelerated scheme for Jacobian computation and it is combined with conjugate gradient scheme (CGS) for fast reconstruction. The method makes explicit use of secant and adjoint information that can be obtained from forward solution of the diffusion equation. This approach reduces the computational time many fold by approximating the system Jacobian successively through low-rank updates. Simulation studies have been carried out with single as well as multiple inhomogeneities. Algorithms are validated using an experimental study carried out on a pork tissue with fat acting as an inhomogeneity. The results obtained through the proposed BMOBIIR and ABMOBIIR approaches are compared with those of Newton-based MOBIIR algorithm. The mean squared error and execution time are used as metrics for comparing the results of reconstruction. We have shown through experimental and simulation studies that Broyden-based MOBIIR and adjoint Broyden-based methods are capable of reconstructing single as well as multiple inhomogeneities in tissue and a tissue-mimicking phantom. Broyden MOBIIR and adjoint Broyden MOBIIR methods are computationally simple and they result in much faster implementations because they avoid direct evaluation of Jacobian. The image reconstructions have been carried out with different initial values using Newton, Broyden, and adjoint Broyden approaches. These algorithms work well when the initial guess is close to the true solution. However, when initial guess is far away from true solution, Newton-based MOBIIR gives better reconstructed images. The proposed methods are found to be stable with noisy measurement data.

GateKeeper: a new hardware architecture for accelerating pre-alignment in DNA short read mapping.

PubMed

Alser, Mohammed; Hassan, Hasan; Xin, Hongyi; Ergin, Oguz; Mutlu, Onur; Alkan, Can

2017-11-01

High throughput DNA sequencing (HTS) technologies generate an excessive number of small DNA segments -called short reads- that cause significant computational burden. To analyze the entire genome, each of the billions of short reads must be mapped to a reference genome based on the similarity between a read and 'candidate' locations in that reference genome. The similarity measurement, called alignment, formulated as an approximate string matching problem, is the computational bottleneck because: (i) it is implemented using quadratic-time dynamic programming algorithms and (ii) the majority of candidate locations in the reference genome do not align with a given read due to high dissimilarity. Calculating the alignment of such incorrect candidate locations consumes an overwhelming majority of a modern read mapper's execution time. Therefore, it is crucial to develop a fast and effective filter that can detect incorrect candidate locations and eliminate them before invoking computationally costly alignment algorithms. We propose GateKeeper, a new hardware accelerator that functions as a pre-alignment step that quickly filters out most incorrect candidate locations. GateKeeper is the first design to accelerate pre-alignment using Field-Programmable Gate Arrays (FPGAs), which can perform pre-alignment much faster than software. When implemented on a single FPGA chip, GateKeeper maintains high accuracy (on average >96%) while providing, on average, 90-fold and 130-fold speedup over the state-of-the-art software pre-alignment techniques, Adjacency Filter and Shifted Hamming Distance (SHD), respectively. The addition of GateKeeper as a pre-alignment step can reduce the verification time of the mrFAST mapper by a factor of 10. https://github.com/BilkentCompGen/GateKeeper. mohammedalser@bilkent.edu.tr or onur.mutlu@inf.ethz.ch or calkan@cs.bilkent.edu.tr. Supplementary data are available at Bioinformatics online. © The Author (2017). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Near Real-Time Automatic Marine Vessel Detection on Optical Satellite Images

NASA Astrophysics Data System (ADS)

Máttyus, G.

2013-05-01

Vessel monitoring and surveillance is important for maritime safety and security, environment protection and border control. Ship monitoring systems based on Synthetic-aperture Radar (SAR) satellite images are operational. On SAR images the ships made of metal with sharp edges appear as bright dots and edges, therefore they can be well distinguished from the water. Since the radar is independent from the sun light and can acquire images also by cloudy weather and rain, it provides a reliable service. Vessel detection from spaceborne optical images (VDSOI) can extend the SAR based systems by providing more frequent revisit times and overcoming some drawbacks of the SAR images (e.g. lower spatial resolution, difficult human interpretation). Optical satellite images (OSI) can have a higher spatial resolution thus enabling the detection of smaller vessels and enhancing the vessel type classification. The human interpretation of an optical image is also easier than as of SAR image. In this paper I present a rapid automatic vessel detection method which uses pattern recognition methods, originally developed in the computer vision field. In the first step I train a binary classifier from image samples of vessels and background. The classifier uses simple features which can be calculated very fast. For the detection the classifier is slided along the image in various directions and scales. The detector has a cascade structure which rejects most of the background in the early stages which leads to faster execution. The detections are grouped together to avoid multiple detections. Finally the position, size(i.e. length and width) and heading of the vessels is extracted from the contours of the vessel. The presented method is parallelized, thus it runs fast (in minutes for 16000 × 16000 pixels image) on a multicore computer, enabling near real-time applications, e.g. one hour from image acquisition to end user.

Fasting, circadian rhythms, and time restricted feeding in healthy lifespan

PubMed Central

Longo, Valter D.; Panda, Satchidananda

2016-01-01

Summary Feeding in most animals is confined to a defined period, leaving short periods of fasting that coincide with sleep. Fasting enables organisms to enter alternative metabolic phases, which rely less on glucose and more on ketone body-like carbon sources. Both intermittent and periodic fasting result in benefits ranging from prevention to the enhanced treatment of diseases. Similarly, time-restricted feeding (TRF), in which feeding time is restricted to certain hours of the day, allows the daily fasting period to last >12 h, thus imparting pleiotropic benefits in multiple organisms. Understanding the mechanistic link between nutrients and the fasting benefits is leading to the identification of fasting mimicking diets (FMDs) that achieve changes similar to those caused by fasting. Given the pleiotropic and sustained benefits of TRF and FMD, both basic science and translational research are warranted to develop fasting-associated interventions into effective and inexpensive treatments with the potential to improve healthspan. PMID:27304506

Implementing forward recovery using checkpointing in distributed systems

NASA Technical Reports Server (NTRS)

Long, Junsheng; Fuchs, W. K.; Abraham, Jacob A.

1991-01-01

The paper describes the implementation of a forward recovery scheme using checkpoints and replicated tasks. The implementation is based on the concept of lookahead execution and rollback validation. In the experiment, two tasks are selected for the normal execution and one for rollback validation. It is shown that the recovery strategy has nearly error-free execution time and an average redundancy lower than TMR.

Exploiting Semantic Web Technologies to Develop OWL-Based Clinical Practice Guideline Execution Engines.

PubMed

Jafarpour, Borna; Abidi, Samina Raza; Abidi, Syed Sibte Raza

2016-01-01

Computerizing paper-based CPG and then executing them can provide evidence-informed decision support to physicians at the point of care. Semantic web technologies especially web ontology language (OWL) ontologies have been profusely used to represent computerized CPG. Using semantic web reasoning capabilities to execute OWL-based computerized CPG unties them from a specific custom-built CPG execution engine and increases their shareability as any OWL reasoner and triple store can be utilized for CPG execution. However, existing semantic web reasoning-based CPG execution engines suffer from lack of ability to execute CPG with high levels of expressivity, high cognitive load of computerization of paper-based CPG and updating their computerized versions. In order to address these limitations, we have developed three CPG execution engines based on OWL 1 DL, OWL 2 DL and OWL 2 DL + semantic web rule language (SWRL). OWL 1 DL serves as the base execution engine capable of executing a wide range of CPG constructs, however for executing highly complex CPG the OWL 2 DL and OWL 2 DL + SWRL offer additional executional capabilities. We evaluated the technical performance and medical correctness of our execution engines using a range of CPG. Technical evaluations show the efficiency of our CPG execution engines in terms of CPU time and validity of the generated recommendation in comparison to existing CPG execution engines. Medical evaluations by domain experts show the validity of the CPG-mediated therapy plans in terms of relevance, safety, and ordering for a wide range of patient scenarios.

AITRAC: Augmented Interactive Transient Radiation Analysis by Computer. User's information manual

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

Not Available

1977-10-01

AITRAC is a program designed for on-line, interactive, DC, and transient analysis of electronic circuits. The program solves linear and nonlinear simultaneous equations which characterize the mathematical models used to predict circuit response. The program features 100 external node--200 branch capability; conversional, free-format input language; built-in junction, FET, MOS, and switch models; sparse matrix algorithm with extended-precision H matrix and T vector calculations, for fast and accurate execution; linear transconductances: beta, GM, MU, ZM; accurate and fast radiation effects analysis; special interface for user-defined equations; selective control of multiple outputs; graphical outputs in wide and narrow formats; and on-line parametermore » modification capability. The user describes the problem by entering the circuit topology and part parameters. The program then automatically generates and solves the circuit equations, providing the user with printed or plotted output. The circuit topology and/or part values may then be changed by the user, and a new analysis, requested. Circuit descriptions may be saved on disk files for storage and later use. The program contains built-in standard models for resistors, voltage and current sources, capacitors, inductors including mutual couplings, switches, junction diodes and transistors, FETS, and MOS devices. Nonstandard models may be constructed from standard models or by using the special equations interface. Time functions may be described by straight-line segments or by sine, damped sine, and exponential functions. 42 figures, 1 table. (RWR)« less

PhosSA: Fast and accurate phosphorylation site assignment algorithm for mass spectrometry data.

PubMed

Saeed, Fahad; Pisitkun, Trairak; Hoffert, Jason D; Rashidian, Sara; Wang, Guanghui; Gucek, Marjan; Knepper, Mark A

2013-11-07

Phosphorylation site assignment of high throughput tandem mass spectrometry (LC-MS/MS) data is one of the most common and critical aspects of phosphoproteomics. Correctly assigning phosphorylated residues helps us understand their biological significance. The design of common search algorithms (such as Sequest, Mascot etc.) do not incorporate site assignment; therefore additional algorithms are essential to assign phosphorylation sites for mass spectrometry data. The main contribution of this study is the design and implementation of a linear time and space dynamic programming strategy for phosphorylation site assignment referred to as PhosSA. The proposed algorithm uses summation of peak intensities associated with theoretical spectra as an objective function. Quality control of the assigned sites is achieved using a post-processing redundancy criteria that indicates the signal-to-noise ratio properties of the fragmented spectra. The quality assessment of the algorithm was determined using experimentally generated data sets using synthetic peptides for which phosphorylation sites were known. We report that PhosSA was able to achieve a high degree of accuracy and sensitivity with all the experimentally generated mass spectrometry data sets. The implemented algorithm is shown to be extremely fast and scalable with increasing number of spectra (we report up to 0.5 million spectra/hour on a moderate workstation). The algorithm is designed to accept results from both Sequest and Mascot search engines. An executable is freely available at http://helixweb.nih.gov/ESBL/PhosSA/ for academic research purposes.

OPAD-EDIFIS Real-Time Processing

NASA Technical Reports Server (NTRS)

Katsinis, Constantine

1997-01-01

The Optical Plume Anomaly Detection (OPAD) detects engine hardware degradation of flight vehicles through identification and quantification of elemental species found in the plume by analyzing the plume emission spectra in a real-time mode. Real-time performance of OPAD relies on extensive software which must report metal amounts in the plume faster than once every 0.5 sec. OPAD software previously written by NASA scientists performed most necessary functions at speeds which were far below what is needed for real-time operation. The research presented in this report improved the execution speed of the software by optimizing the code without changing the algorithms and converting it into a parallelized form which is executed in a shared-memory multiprocessor system. The resulting code was subjected to extensive timing analysis. The report also provides suggestions for further performance improvement by (1) identifying areas of algorithm optimization, (2) recommending commercially available multiprocessor architectures and operating systems to support real-time execution and (3) presenting an initial study of fault-tolerance requirements.

Influence of the distance in a roundhouse kick's execution time and impact force in Taekwondo.

PubMed

Falco, Coral; Alvarez, Octavio; Castillo, Isabel; Estevan, Isaac; Martos, Julio; Mugarra, Fernando; Iradi, Antonio

2009-02-09

Taekwondo, originally a Korean martial art, is well known for its kicks. One of the most frequently used kicks in competition is Bandal Chagui or roundhouse kick. Excellence in Taekwondo relies on the ability to make contact with the opponent's trunk or face with enough force in as little time as possible, while at the same time avoiding being hit. Thus, the distance between contestants is an important variable to be taken into consideration. Thirty-one Taekwondo athletes in two different groups (expert and novice, according to experience in competition) took part in this study. The purpose of this study was to examine both impact force and execution time in a Bandal Chagui or roundhouse kick, and to explore the effect of execution distance in these two variables. A new model was developed in order to measure the force exerted by the body on a load. A force platform and a contact platform were used to measure these variables. The results showed that there are no significant differences in terms of impact force in relation to execution distance in expert competitors. Significant and positive correlations between body mass and impact force (p<.01) seem to mean that novice competitors use their body mass to generate high impact forces. Significant differences were found in competitive experience and execution time for the three different distances of kicking considered in the study. Standing at a certain further distance from the opponent should be an advantage for competitors who are used to kick from a further distance in their training.

Resource-Aware Mobile-Based Health Monitoring.

PubMed

Masud, Mohammad M; Adel Serhani, Mohamed; Navaz, Alramzana Nujum

2017-03-01

Monitoring heart diseases often requires frequent measurements of electrocardiogram (ECG) signals at different periods of the day, and at different situations (e.g., traveling, and exercising). This can only be implemented using mobile devices in order to cope with mobility of patients under monitoring, thus supporting continuous monitoring practices. However, these devices are energy-aware, have limited computing resources (e.g., CPU speed and memory), and might lose network connectivity, which makes it very challenging to maintain a continuity of the monitoring episode. In this paper, we propose a mobile monitoring solution to cope with these challenges by compromising on the fly resources availability, battery level, and network intermittence. In order to solve this problem, first we divide the whole process into several subtasks such that each subtask can be executed sequentially either in the server or in the mobile or in parallel in both devices. Then, we developed a mathematical model that considers all the constraints and finds a dynamic programing solution to obtain the best execution path (i.e., which substep should be done where). The solution guarantees an optimum execution time, while considering device battery availability, execution and transmission time, and network availability. We conducted a series of experiments to evaluate our proposed approach using some key monitoring tasks starting from preprocessing to classification and prediction. The results we have obtained proved that our approach gives the best (lowest) running time for any combination of factors including processing speed, input size, and network bandwidth. Compared to several greedy but nonoptimal solutions, the execution time of our approach was at least 10 times faster and consumed 90% less energy.

Dopamine Manipulation Affects Response Vigor Independently of Opportunity Cost.

PubMed

Zénon, Alexandre; Devesse, Sophie; Olivier, Etienne

2016-09-14

Dopamine is known to be involved in regulating effort investment in relation to reward, and the disruption of this mechanism is thought to be central in some pathological situations such as Parkinson's disease, addiction, and depression. According to an influential model, dopamine plays this role by encoding the opportunity cost, i.e., the average value of forfeited actions, which is an important parameter to take into account when making decisions about which action to undertake and how fast to execute it. We tested this hypothesis by asking healthy human participants to perform two effort-based decision-making tasks, following either placebo or levodopa intake in a double blind within-subject protocol. In the effort-constrained task, there was a trade-off between the amount of force exerted and the time spent in executing the task, such that investing more effort decreased the opportunity cost. In the time-constrained task, the effort duration was constant, but exerting more force allowed the subject to earn more substantial reward instead of saving time. Contrary to the model predictions, we found that levodopa caused an increase in the force exerted only in the time-constrained task, in which there was no trade-off between effort and opportunity cost. In addition, a computational model showed that dopamine manipulation left the opportunity cost factor unaffected but altered the ratio between the effort cost and reinforcement value. These findings suggest that dopamine does not represent the opportunity cost but rather modulates how much effort a given reward is worth. Dopamine has been proposed in a prevalent theory to signal the average reward rate, used to estimate the cost of investing time in an action, also referred to as opportunity cost. We contrasted the effect of dopamine manipulation in healthy participants in two tasks, in which increasing response vigor (i.e., the amount of effort invested in an action) allowed either to save time or to earn more reward. We found that levodopa-a synthetic precursor of dopamine-increases response vigor only in the latter situation, demonstrating that, rather than the opportunity cost, dopamine is involved in computing the expected value of effort. Copyright © 2016 the authors 0270-6474/16/369516-10$15.00/0.

Fast Marching Tree: a Fast Marching Sampling-Based Method for Optimal Motion Planning in Many Dimensions*

PubMed Central

Janson, Lucas; Schmerling, Edward; Clark, Ashley; Pavone, Marco

2015-01-01

In this paper we present a novel probabilistic sampling-based motion planning algorithm called the Fast Marching Tree algorithm (FMT*). The algorithm is specifically aimed at solving complex motion planning problems in high-dimensional configuration spaces. This algorithm is proven to be asymptotically optimal and is shown to converge to an optimal solution faster than its state-of-the-art counterparts, chiefly PRM* and RRT*. The FMT* algorithm performs a “lazy” dynamic programming recursion on a predetermined number of probabilistically-drawn samples to grow a tree of paths, which moves steadily outward in cost-to-arrive space. As such, this algorithm combines features of both single-query algorithms (chiefly RRT) and multiple-query algorithms (chiefly PRM), and is reminiscent of the Fast Marching Method for the solution of Eikonal equations. As a departure from previous analysis approaches that are based on the notion of almost sure convergence, the FMT* algorithm is analyzed under the notion of convergence in probability: the extra mathematical flexibility of this approach allows for convergence rate bounds—the first in the field of optimal sampling-based motion planning. Specifically, for a certain selection of tuning parameters and configuration spaces, we obtain a convergence rate bound of order O(n−1/d+ρ), where n is the number of sampled points, d is the dimension of the configuration space, and ρ is an arbitrarily small constant. We go on to demonstrate asymptotic optimality for a number of variations on FMT*, namely when the configuration space is sampled non-uniformly, when the cost is not arc length, and when connections are made based on the number of nearest neighbors instead of a fixed connection radius. Numerical experiments over a range of dimensions and obstacle configurations confirm our the-oretical and heuristic arguments by showing that FMT*, for a given execution time, returns substantially better solutions than either PRM* or RRT*, especially in high-dimensional configuration spaces and in scenarios where collision-checking is expensive. PMID:27003958

The generalized centroid difference method for picosecond sensitive determination of lifetimes of nuclear excited states using large fast-timing arrays

NASA Astrophysics Data System (ADS)

Régis, J.-M.; Mach, H.; Simpson, G. S.; Jolie, J.; Pascovici, G.; Saed-Samii, N.; Warr, N.; Bruce, A.; Degenkolb, J.; Fraile, L. M.; Fransen, C.; Ghita, D. G.; Kisyov, S.; Koester, U.; Korgul, A.; Lalkovski, S.; Mărginean, N.; Mutti, P.; Olaizola, B.; Podolyak, Z.; Regan, P. H.; Roberts, O. J.; Rudigier, M.; Stroe, L.; Urban, W.; Wilmsen, D.

2013-10-01

A novel method for direct electronic “fast-timing” lifetime measurements of nuclear excited states via γ-γ coincidences using an array equipped with N∈N equally shaped very fast high-resolution LaBr3(Ce) scintillator detectors is presented. Analogous to the mirror symmetric centroid difference method, the generalized centroid difference method provides two independent “start” and “stop” time spectra obtained by a superposition of the N(N-1)γ-γ time difference spectra of the N detector fast-timing system. The two fast-timing array time spectra correspond to a forward and reverse gating of a specific γ-γ cascade. Provided that the energy response and the electronic time pick-off of the detectors are almost equal, a mean prompt response difference between start and stop events is calibrated and used as a single correction for lifetime determination. These combined fast-timing arrays mean γ-γ time-walk characteristics can be determined for 40 keV

77 FR 29397 - Order Granting Application of BOX Options Exchange, LLC for a Limited Exemption From Exchange Act...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-17

... for strict price-time priority execution (``Trading System'').\\2\\ The BOX Book and the Exchange Rules...'') as set forth in Exchange Rule 7150 are an exception to the strict price-time priority execution that... in the Application, BOX will operate a fully automated electronic book (``BOX Book'') for orders to...

Two criteria for the selection of assembly plans - Maximizing the flexibility of sequencing the assembly tasks and minimizing the assembly time through parallel execution of assembly tasks

NASA Technical Reports Server (NTRS)

Homem De Mello, Luiz S.; Sanderson, Arthur C.

1991-01-01

The authors introduce two criteria for the evaluation and selection of assembly plans. The first criterion is to maximize the number of different sequences in which the assembly tasks can be executed. The second criterion is to minimize the total assembly time through simultaneous execution of assembly tasks. An algorithm that performs a heuristic search for the best assembly plan over the AND/OR graph representation of assembly plans is discussed. Admissible heuristics for each of the two criteria introduced are presented. Some implementation issues that affect the computational efficiency are addressed.

Acute hypoglycemia impairs executive cognitive function in adults with and without type 1 diabetes.

PubMed

Graveling, Alex J; Deary, Ian J; Frier, Brian M

2013-10-01

Acute hypoglycemia impairs cognitive function in several domains. Executive cognitive function governs organization of thoughts, prioritization of tasks, and time management. This study examined the effect of acute hypoglycemia on executive function in adults with and without diabetes. Thirty-two adults with and without type 1 diabetes with no vascular complications or impaired awareness of hypoglycemia were studied. Two hyperinsulinemic glucose clamps were performed at least 2 weeks apart in a single-blind, counterbalanced order, maintaining blood glucose at 4.5 mmol/L (euglycemia) or 2.5 mmol/L (hypoglycemia). Executive functions were assessed with a validated test suite (Delis-Kaplan Executive Function). A general linear model (repeated-measures ANOVA) was used. Glycemic condition (euglycemia or hypoglycemia) was the within-participant factor. Between-participant factors were order of session (euglycemia-hypoglycemia or hypoglycemia-euglycemia), test battery used, and diabetes status (with or without diabetes). Compared with euglycemia, executive functions (with one exception) were significantly impaired during hypoglycemia; lower test scores were recorded with more time required for completion. Large Cohen d values (>0.8) suggest that hypoglycemia induces decrements in aspects of executive function with large effect sizes. In some tests, the performance of participants with diabetes was more impaired than those without diabetes. Executive cognitive function, which is necessary to carry out many everyday activities, is impaired during hypoglycemia in adults with and without type 1 diabetes. This important aspect of cognition has not received previous systematic study with respect to hypoglycemia. The effect size is large in terms of both accuracy and speed.

Preoperative fasting: knowledge and perceptions.

PubMed

Baril, Patrice; Portman, Harriet

2007-10-01

Preoperative patient fasting is an essential element of the patient preparation process, but patients may be fasting for excessive lengths of time. Investigators at one facility used semi-structured interviews to explore the knowledge and beliefs of patients, nurses, and anesthesia care providers regarding the practice of preoperative patient fasting. Findings indicate that some patients had excessive fasting times, and practitioners had erroneous perceptions about patient knowledge regarding the rationale for fasting and compliance with instructions. Clinicians expressed concern about the effects of excessive fasting but were reluctant to relax the policy.

Preoperative fasting times in elective surgical patients at a referral Hospital in Botswana

PubMed Central

Abebe, Worknehe Agegnehu; Rukewe, Ambrose; Bekele, Negussie Alula; Stoffel, Moeng; Dichabeng, Mompelegi Nicoh; Shifa, Jemal Zeberga

2016-01-01

Introduction Adults and children are required to fast before anaesthesia to reduce the risk of regurgitation and aspiration of gastric contents. However, prolonged periods of fasting are unnecessary and may cause complications. This study was conducted to evaluate preoperative fasting period in our centre and compare it with the ASA recommendations and factors that influence fasting periods. Methods This is a cross-sectional study of preoperative fasting times among elective surgical patients. A total numbers of 260 patients were interviewed as they arrived at the reception area of operating theatre using questionnaire. Results Majority of patients (98.1%) were instructed to fast from midnight. Fifteen patients (5.8%) reported that they were told the importance of preoperative fasting. The mean fasting period were 15.9±2.5 h (range 12.0-25.3 h) for solids and 15.3±2.3 h (range 12.0-22.0 h) for liquids. The mean duration of fasting was significantly longer for patients operated after midday compared to those operated before midday, p<0.001. Conclusion The mean fasting periods were 7.65 times longer for clear liquid and 2.5 times for solids than the ASA guidelines. It is imperative that the Hospital should establish Preoperative fasting policies and teach the staff who should ensure compliance with guidelines. PMID:27222691

The international spinal cord injury endocrine and metabolic function basic data set.

PubMed

Bauman, W A; Biering-Sørensen, F; Krassioukov, A

2011-10-01

To develop the International Spinal Cord Injury (SCI) Endocrine and Metabolic Function Basic Data Set within the framework of the International SCI Data Sets that would facilitate consistent collection and reporting of basic endocrine and metabolic findings in the SCI population. International. The International SCI Endocrine and Metabolic Function Data Set was developed by a working group. The initial data set document was revised on the basis of suggestions from members of the Executive Committee of the International SCI Standards and Data Sets, the International Spinal Cord Society (ISCoS) Executive and Scientific Committees, American Spinal Injury Association (ASIA) Board, other interested organizations and societies, and individual reviewers. In addition, the data set was posted for 2 months on ISCoS and ASIA websites for comments. The final International SCI Endocrine and Metabolic Function Data Set contains questions on the endocrine and metabolic conditions diagnosed before and after spinal cord lesion. If available, information collected before injury is to be obtained only once, whereas information after injury may be collected at any time. These data include information on diabetes mellitus, lipid disorders, osteoporosis, thyroid disease, adrenal disease, gonadal disease and pituitary disease. The question of gonadal status includes stage of sexual development and that for females also includes menopausal status. Data will be collected for body mass index and for the fasting serum lipid profile. The complete instructions for data collection and the data sheet itself are freely available on the websites of ISCoS (http://www.iscos.org.uk) and ASIA (http://www.asia-spinalinjury.org).

Investigating the effects of caffeine on executive functions using traditional Stroop and a new ecologically-valid virtual reality task, the Jansari assessment of Executive Functions (JEF(©)).

PubMed

Soar, K; Chapman, E; Lavan, N; Jansari, A S; Turner, J J D

2016-10-01

Caffeine has been shown to have effects on certain areas of cognition, but in executive functioning the research is limited and also inconsistent. One reason could be the need for a more sensitive measure to detect the effects of caffeine on executive function. This study used a new non-immersive virtual reality assessment of executive functions known as JEF(©) (the Jansari Assessment of Executive Function) alongside the 'classic' Stroop Colour-Word task to assess the effects of a normal dose of caffeinated coffee on executive function. Using a double-blind, counterbalanced within participants procedure 43 participants were administered either a caffeinated or decaffeinated coffee and completed the 'JEF(©)' and Stroop tasks, as well as a subjective mood scale and blood pressure pre- and post condition on two separate occasions a week apart. JEF(©) yields measures for eight separate aspects of executive functions, in addition to a total average score. Findings indicate that performance was significantly improved on the planning, creative thinking, event-, time- and action-based prospective memory, as well as total JEF(©) score following caffeinated coffee relative to the decaffeinated coffee. The caffeinated beverage significantly decreased reaction times on the Stroop task, but there was no effect on Stroop interference. The results provide further support for the effects of a caffeinated beverage on cognitive functioning. In particular, it has demonstrated the ability of JEF(©) to detect the effects of caffeine across a number of executive functioning constructs, which weren't shown in the Stroop task, suggesting executive functioning improvements as a result of a 'typical' dose of caffeine may only be detected by the use of more real-world, ecologically valid tasks. Copyright © 2016 Elsevier Ltd. All rights reserved.

Can training in a real-time strategy video game attenuate cognitive decline in older adults?

PubMed

Basak, Chandramallika; Boot, Walter R; Voss, Michelle W; Kramer, Arthur F

2008-12-01

Declines in various cognitive abilities, particularly executive control functions, are observed in older adults. An important goal of cognitive training is to slow or reverse these age-related declines. However, opinion is divided in the literature regarding whether cognitive training can engender transfer to a variety of cognitive skills in older adults. In the current study, the authors trained older adults in a real-time strategy video game for 23.5 hr in an effort to improve their executive functions. A battery of cognitive tasks, including tasks of executive control and visuospatial skills, were assessed before, during, and after video-game training. The trainees improved significantly in the measures of game performance. They also improved significantly more than the control participants in executive control functions, such as task switching, working memory, visual short-term memory, and reasoning. Individual differences in changes in game performance were correlated with improvements in task switching. The study has implications for the enhancement of executive control processes of older adults. Copyright (c) 2009 APA, all rights reserved.

Supporting Real-Time Operations and Execution through Timeline and Scheduling Aids

NASA Technical Reports Server (NTRS)

Marquez, Jessica J.; Pyrzak, Guy; Hashemi, Sam; Ahmed, Samia; McMillin, Kevin Edward; Medwid, Joseph Daniel; Chen, Diana; Hurtle, Esten

2013-01-01

Since 2003, the NASA Ames Research Center has been actively involved in researching and advancing the state-of-the-art of planning and scheduling tools for NASA mission operations. Our planning toolkit SPIFe (Scheduling and Planning Interface for Exploration) has supported a variety of missions and field tests, scheduling activities for Mars rovers as well as crew on-board International Space Station and NASA earth analogs. The scheduled plan is the integration of all the activities for the day/s. In turn, the agents (rovers, landers, spaceships, crew) execute from this schedule while the mission support team members (e.g., flight controllers) follow the schedule during execution. Over the last couple of years, our team has begun to research and validate methods that will better support users during realtime operations and execution of scheduled activities. Our team utilizes human-computer interaction principles to research user needs, identify workflow processes, prototype software aids, and user test these. This paper discusses three specific prototypes developed and user tested to support real-time operations: Score Mobile, Playbook, and Mobile Assistant for Task Execution (MATE).

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.

24 CFR 886.334 - Execution of housing assistance payments contract.

Code of Federal Regulations, 2010 CFR

2010-04-01

... DIRECT LOAN PROGRAM, SECTION 202 SUPPORTIVE HOUSING FOR THE ELDERLY PROGRAM AND SECTION 811 SUPPORTIVE... Market Rent or the exception rent provided in § 886.310 in effect at the time of execution of the...

Post-game analysis: An initial experiment for heuristic-based resource management in concurrent systems

NASA Technical Reports Server (NTRS)

Yan, Jerry C.

1987-01-01

In concurrent systems, a major responsibility of the resource management system is to decide how the application program is to be mapped onto the multi-processor. Instead of using abstract program and machine models, a generate-and-test framework known as 'post-game analysis' that is based on data gathered during program execution is proposed. Each iteration consists of (1) (a simulation of) an execution of the program; (2) analysis of the data gathered; and (3) the proposal of a new mapping that would have a smaller execution time. These heuristics are applied to predict execution time changes in response to small perturbations applied to the current mapping. An initial experiment was carried out using simple strategies on 'pipeline-like' applications. The results obtained from four simple strategies demonstrated that for this kind of application, even simple strategies can produce acceptable speed-up with a small number of iterations.

Executive Functions and Prefrontal Cortex: A Matter of Persistence?

PubMed Central

Ball, Gareth; Stokes, Paul R.; Rhodes, Rebecca A.; Bose, Subrata K.; Rezek, Iead; Wink, Alle-Meije; Lord, Louis-David; Mehta, Mitul A.; Grasby, Paul M.; Turkheimer, Federico E.

2011-01-01

Executive function is thought to originates from the dynamics of frontal cortical networks. We examined the dynamic properties of the blood oxygen level dependent time-series measured with functional MRI (fMRI) within the prefrontal cortex (PFC) to test the hypothesis that temporally persistent neural activity underlies performance in three tasks of executive function. A numerical estimate of signal persistence, the Hurst exponent, postulated to represent the coherent firing of cortical networks, was determined and correlated with task performance. Increasing persistence in the lateral PFC was shown to correlate with improved performance during an n-back task. Conversely, we observed a correlation between persistence and increasing commission error – indicating a failure to inhibit a prepotent response – during a Go/No-Go task. We propose that persistence within the PFC reflects dynamic network formation and these findings underline the importance of frequency analysis of fMRI time-series in the study of executive functions. PMID:21286223

Acute stress affects prospective memory functions via associative memory processes.

PubMed

Szőllősi, Ágnes; Pajkossy, Péter; Demeter, Gyula; Kéri, Szabolcs; Racsmány, Mihály

2018-01-01

Recent findings suggest that acute stress can improve the execution of delayed intentions (prospective memory, PM). However, it is unclear whether this improvement can be explained by altered executive control processes or by altered associative memory functioning. To investigate this issue, we used physical-psychosocial stressors to induce acute stress in laboratory settings. Then participants completed event- and time-based PM tasks requiring the different contribution of control processes and a control task (letter fluency) frequently used to measure executive functions. According to our results, acute stress had no impact on ongoing task performance, time-based PM, and verbal fluency, whereas it enhanced event-based PM as measured by response speed for the prospective cues. Our findings indicate that, here, acute stress did not affect executive control processes. We suggest that stress affected event-based PM via associative memory processes. Copyright © 2017 Elsevier B.V. All rights reserved.

Power-Aware Compiler Controllable Chip Multiprocessor

NASA Astrophysics Data System (ADS)

Shikano, Hiroaki; Shirako, Jun; Wada, Yasutaka; Kimura, Keiji; Kasahara, Hironori

A power-aware compiler controllable chip multiprocessor (CMP) is presented and its performance and power consumption are evaluated with the optimally scheduled advanced multiprocessor (OSCAR) parallelizing compiler. The CMP is equipped with power control registers that change clock frequency and power supply voltage to functional units including processor cores, memories, and an interconnection network. The OSCAR compiler carries out coarse-grain task parallelization of programs and reduces power consumption using architectural power control support and the compiler's power saving scheme. The performance evaluation shows that MPEG-2 encoding on the proposed CMP with four CPUs results in 82.6% power reduction in real-time execution mode with a deadline constraint on its sequential execution time. Furthermore, MP3 encoding on a heterogeneous CMP with four CPUs and four accelerators results in 53.9% power reduction at 21.1-fold speed-up in performance against its sequential execution in the fastest execution mode.

Checkpoint-based forward recovery using lookahead execution and rollback validation in parallel and distributed systems. Ph.D. Thesis, 1992

NASA Technical Reports Server (NTRS)

Long, Junsheng

1994-01-01

This thesis studies a forward recovery strategy using checkpointing and optimistic execution in parallel and distributed systems. The approach uses replicated tasks executing on different processors for forwared recovery and checkpoint comparison for error detection. To reduce overall redundancy, this approach employs a lower static redundancy in the common error-free situation to detect error than the standard N Module Redundancy scheme (NMR) does to mask off errors. For the rare occurrence of an error, this approach uses some extra redundancy for recovery. To reduce the run-time recovery overhead, look-ahead processes are used to advance computation speculatively and a rollback process is used to produce a diagnosis for correct look-ahead processes without rollback of the whole system. Both analytical and experimental evaluation have shown that this strategy can provide a nearly error-free execution time even under faults with a lower average redundancy than NMR.

Bypassing Races in Live Applications with Execution Filters

DTIC Science & Technology

2010-01-01

LOOM creates the needed locks and semaphores on demand. The first time a lock or semaphore is refer- enced by one of the inserted synchronization ...runtime. LOOM provides a flexible and safe language for develop- ers to write execution filters that explicitly synchronize code. It then uses an...first compile their application with LOOM. At runtime, to workaround a race, an application developer writes an execution filter that synchronizes the

Reconfiguration in Robust Distributed Real-Time Systems Based on Global Checkpoints

DTIC Science & Technology

1991-12-01

achieved by utilizing distributed systems in which a single application program executes on multiple processors, connected to a network. The distributed...single application program executes on multiple proces- sors, connected to a network. The distributed nature of such systems make it possible to ...resident at every node. How - ever, the responsibility for execution of a particular function is assigned to only one node in this framework. This function

Assessment of executive functions in patients with obsessive compulsive disorder by NeuroVR.

PubMed

La Paglia, Filippo; La Cascia, Caterina; Rizzo, Rosalinda; Riva, Giuseppe; La Barbera, Daniele

2012-01-01

Executive functions are often impaired in obsessive-compulsive disorder (OCD). We used a Virtual Reality version of the Multiple Errand Test (VMET) - developed dusing the free NeuroVR software (http://www.neurovr.org) - to evaluate the executive functions in daily life in 10 OCD patients and 10 controls. It is performed in a shopping setting where there are items to be bought and information to be obtained. The execution time for the whole task was higher in patients with OCD compared to controls, suggesting that patients with OCD need more time in planning than controls. The same difference was found in the partial errors during the task. Furthermore, the mean rank for and for interpretation failures is higher for controls, while the values of divided attention and the of self correction seems to be lower in controls. We think that obsessive patients tend to work with greater diligence and observance of rules than controls. In conclusion, these results provide initial support for the feasibility of VMET as assessment tool of executive functions. Specifically, the significant correlation found between the VMET and the neuropsychological battery support the ecological validity of VMET as an instrument for the evaluation of executive functions in patients with OCD.

Does the circadian pattern for acute cardiac events presentation vary with fasting?

PubMed

Al Suwaidi, J; Bener, A; Gehani, A A; Behair, S; Al Mohanadi, D; Salam, A; Al Binali, H A

2006-01-01

Over one billion Muslims fast worldwide during the month of Ramadan. The impact of fasting on circadian presentation with acute cardiac events is unknown. To determine if fasting has any effect on the circadian presentation of acute cardiac events. A prospective study in a general hospital. Patients with acute coronary events were divided into two groups based on the history of fasting. Information about age, gender, cardiovascular risk factor profiles and outcome was collected. The relationship of time of presentation of initial symptoms with fasting was evaluated using Student's t-test, Mann-Whitney U-test and chi2 analysis. Of the 1019 patients hospitalized during the study period, 162 were fasting. Although, fasting patients were more likely to present to the emergency department in the time periods 5-6 AM (10.5% vs 6.3%) and 11 PM (11.1% vs 7.1%) and were less likely to present in the time periods 1-2 PM (3.7% vs 7.2%) and 5-6 PM (3.7% vs 7.0%); these differences were not statistically significant. Fasting patients were less likely to have their symptoms start between 5 and 8 AM (11.1% vs 19.4%) and more likely to have symptoms between 5 and 6 PM (11.1% vs 6.0%) and 3 and 4 AM (11.1% vs 6.9%). These differences for time of initial symptoms were statistically significant (P=0.002). Exogenous factors associated with fasting, namely, the changes in food intake and/or sleep timings, affect the circadian rhythm and influence the timing of presentation of acute coronary events.

Executive and Perceptual Distraction in Visual Working Memory

PubMed Central

2017-01-01

The contents of visual working memory are likely to reflect the influence of both executive control resources and information present in the environment. We investigated whether executive attention is critical in the ability to exclude unwanted stimuli by introducing concurrent potentially distracting irrelevant items to a visual working memory paradigm, and manipulating executive load using simple or more demanding secondary verbal tasks. Across 7 experiments varying in presentation format, timing, stimulus set, and distractor number, we observed clear disruptive effects of executive load and visual distraction, but relatively minimal evidence supporting an interactive relationship between these factors. These findings are in line with recent evidence using delay-based interference, and suggest that different forms of attentional selection operate relatively independently in visual working memory. PMID:28414499

Bilingualism, executive control, and age at diagnosis among people with early-stage Alzheimer's disease in Wales.

PubMed

Clare, Linda; Whitaker, Christopher J; Craik, Fergus I M; Bialystok, Ellen; Martyr, Anthony; Martin-Forbes, Pamela A; Bastable, Alexandra J M; Pye, Kirstie L; Quinn, Catherine; Thomas, Enlli M; Gathercole, Virginia C Mueller; Hindle, John V

2016-09-01

The observation of a bilingual advantage in executive control tasks involving inhibition and management of response conflict suggests that being bilingual might contribute to increased cognitive reserve. In support of this, recent evidence indicates that bilinguals develop Alzheimer's disease (AD) later than monolinguals, and may retain an advantage in performance on executive control tasks. We compared age at the time of receiving an AD diagnosis in bilingual Welsh/English speakers (n = 37) and monolingual English speakers (n = 49), and assessed the performance of bilinguals (n = 24) and monolinguals (n = 49) on a range of executive control tasks. There was a non-significant difference in age at the time of diagnosis, with bilinguals being on average 3 years older than monolinguals, but bilinguals were also significantly more cognitively impaired at the time of diagnosis. There were no significant differences between monolinguals and bilinguals in performance on executive function tests, but bilinguals appeared to show relative strengths in the domain of inhibition and response conflict. Bilingual Welsh/English speakers with AD do not show a clear advantage in executive function over monolingual English speakers, but may retain some benefits in inhibition and management of response conflict. There may be a delay in onset of AD in Welsh/English bilinguals, but if so, it is smaller than that found in some other clinical populations. In this Welsh sample, bilinguals with AD came to the attention of services later than monolinguals, and reasons for this pattern could be explored further. © 2014 The British Psychological Society.

The longitudinal development of social and executive functions in late adolescence and early adulthood

PubMed Central

Taylor, Sophie J.; Barker, Lynne A.; Heavey, Lisa; McHale, Sue

2015-01-01

Our earlier work suggests that, executive functions and social cognition show protracted development into late adolescence and early adulthood (Taylor et al., 2013). However, it remains unknown whether these functions develop linearly or non-linearly corresponding to dynamic changes to white matter density at these age ranges. Executive functions are particularly in demand during the transition to independence and autonomy associated with this age range (Ahmed and Miller, 2011). Previous research examining executive function (Romine and Reynolds, 2005) and social cognition (Dumontheil et al., 2010a) in late adolescence has utilized a cross sectional design. The current study employed a longitudinal design with 58 participants aged 17, 18, and 19 years completing social cognition and executive function tasks, Wechsler Abbreviated Scale of Intelligence (Wechsler, 1999), Positive and Negative Affect Schedule (Watson et al., 1988), and Hospital Anxiety and Depression Scale (Zigmond and Snaith, 1983) at Time 1 with follow up testing 12–16 months later. Inhibition, rule detection, strategy generation and planning executive functions and emotion recognition with dynamic stimuli showed longitudinal development between time points. Self-report empathy and emotion recognition functions using visual static and auditory stimuli were stable by age 17 whereas concept formation declined between time points. The protracted development of some functions may reflect continued brain maturation into late adolescence and early adulthood including synaptic pruning (Sowell et al., 2001) and changes to functional connectivity (Stevens et al., 2007) and/or environmental change. Clinical implications, such as assessing the effectiveness of rehabilitation following Head Injury, are discussed. PMID:26441579

Evaluating executive function in patients with temporal lobe epilepsy using the frontal assessment battery.

PubMed

Agah, Elmira; Asgari-Rad, Nasima; Ahmadi, Mona; Tafakhori, Abbas; Aghamollaii, Vajiheh

2017-07-01

Previous studies have demonstrated executive dysfunction in patients with temporal lobe epilepsy (TLE). Frontal assessment battery (FAB) is a short neuropsychological tool that was developed for assessment of frontal lobe function in a clinical setting. The aim of the present study is to evaluate the clinical utility of FAB for detection of executive dysfunction in TLE patients. Forty-eight TLE patients and 48 sex and age-matched healthy controls participated in this study. Compared to healthy participants, the total FAB score was significantly lower among the TLE patients. TLE patients performed significantly worse at the mental flexibility, motor programming, sensitivity to interference and inhibitory control tasks. The duration of time has been passed since the last seizure was the only significant predictor of FAB score and patients who had a seizure less than a week before the evaluation time, had significantly lower FAB scores. The number of antiepileptic drugs (AEDs) did not influence the executive function in this study; however, sodium valproate was found to affect the mental flexibility. In conclusion, impaired executive function is common in TLE patients, and we suggest that FAB is a clinically applicable tool to monitor it. Moreover, we found that the time of the last seizure is a significant predictor of executive functioning and patients' performance may become worse up to seven days after a seizure. We also recommend that clinicians evaluate the cognitive adverse effects of AEDs especially sodium valproate, which was found to affect the mental flexibility in this study. Copyright © 2017 Elsevier B.V. All rights reserved.

A common neural code for similar conscious experiences in different individuals

PubMed Central

Naci, Lorina; Cusack, Rhodri; Anello, Mimma; Owen, Adrian M.

2014-01-01

The interpretation of human consciousness from brain activity, without recourse to speech or action, is one of the most provoking and challenging frontiers of modern neuroscience. We asked whether there is a common neural code that underpins similar conscious experiences, which could be used to decode these experiences in the absence of behavior. To this end, we used richly evocative stimulation (an engaging movie) portraying real-world events to elicit a similar conscious experience in different people. Common neural correlates of conscious experience were quantified and related to measurable, quantitative and qualitative, executive components of the movie through two additional behavioral investigations. The movie’s executive demands drove synchronized brain activity across healthy participants’ frontal and parietal cortices in regions known to support executive function. Moreover, the timing of activity in these regions was predicted by participants’ highly similar qualitative experience of the movie’s moment-to-moment executive demands, suggesting that synchronization of activity across participants underpinned their similar experience. Thus we demonstrate, for the first time to our knowledge, that a neural index based on executive function reliably predicted every healthy individual’s similar conscious experience in response to real-world events unfolding over time. This approach provided strong evidence for the conscious experience of a brain-injured patient, who had remained entirely behaviorally nonresponsive for 16 y. The patient’s executive engagement and moment-to-moment perception of the movie content were highly similar to that of every healthy participant. These findings shed light on the common basis of human consciousness and enable the interpretation of conscious experience in the absence of behavior. PMID:25225384

Concurrent and Short-term Prospective Relations among Neurocognitive Functioning, Coping, and Depressive Symptoms in Youth

PubMed Central

Evans, Lindsay D.; Kouros, Chrystyna D.; Samanez-Larkin, Silvia; Garber, Judy

2016-01-01

Objective The present short-term longitudinal study examined the concurrent and prospective relations among executive functioning (i.e., working memory and cognitive flexibility), coping (primary and secondary control coping), and depressive symptoms in children. Method Participants were 192 children between 9 and 15 years old (mean age = 12.36 years, SD = 1.77) recruited from the community. Youth were individually administered neuropsychological measures of executive functioning and intelligence, and completed self-report measures of executive dysfunction, coping, and depressive symptoms in small groups; the latter two measures were completed again four months later (Time 2). Linear regression analyses were used to examine direct associations among executive functions, coping, and depressive symptoms, and a bootstrapping procedure was used to test indirect effects of executive functioning on depressive symptoms through coping. Results Significant prospective relations were found between working memory measured at Time 1 (T1) and both primary and secondary control coping measured at Time 2 (T2), controlling for T1 coping. T1 cognitive flexibility significantly predicted T2 secondary control coping, controlling for T1 coping. Working memory deficits significantly predicted increases in depressive symptoms four months later, controlling for T1 depressive symptoms. Bootstrap analyses revealed that primary and secondary control coping each partially mediated the relation between working memory and depressive symptoms; secondary control coping partially mediated the relation between cognitive flexibility and depressive symptoms. Conclusion Coping may be one pathway through which deficits in executive functioning contribute to children's symptoms of depression. PMID:25651455

Rule-Based Runtime Verification

NASA Technical Reports Server (NTRS)

Barringer, Howard; Goldberg, Allen; Havelund, Klaus; Sen, Koushik

2003-01-01

We present a rule-based framework for defining and implementing finite trace monitoring logics, including future and past time temporal logic, extended regular expressions, real-time logics, interval logics, forms of quantified temporal logics, and so on. Our logic, EAGLE, is implemented as a Java library and involves novel techniques for rule definition, manipulation and execution. Monitoring is done on a state-by-state basis, without storing the execution trace.

Repetitive thinking, executive functioning, and depressive mood in the elderly.

PubMed

Philippot, Pierre; Agrigoroaei, Stefan

2017-11-01

Previous findings and the depressive-executive dysfunction hypothesis suggest that the established association between executive functioning and depression is accounted for by repetitive thinking. Investigating the association between executive functioning, repetitive thinking, and depressive mood, the present study empirically tested this mediational model in a sample of older adults, while focusing on both concrete and abstract repetitive thinking. This latter distinction is important given the potential protective role of concrete repetitive thinking, in contrast to the depletive effect of abstract repetitive thinking. A sample of 43 elderly volunteers, between 75 and 95 years of age, completed tests of executive functioning (the Stroop test, the Trail Making test, and the Fluency test), and questionnaires of repetitive thinking and depression. Positive correlations were observed between abstract repetitive thinking and depressive mood, and between concrete repetitive thinking and executive functioning; a negative correlation was observed between depressive mood and executive functioning. Further, mediational analysis evidenced that the relation between executive functioning and depressive mood was mediated by abstract repetitive thinking. The present data provide, for the first time, empirical support to the depressive-executive dysfunction hypothesis: the lack of executive resources would favor a mode of abstract repetitive thinking, which in turn would deplete mood. It suggests that clinical intervention targeting depression in the elderly should take into consideration repetitive thinking modes and the executive resources needed to disengage from rumination.

Prospective memory in multiple sclerosis: The impact of cue distinctiveness and executive functioning.

PubMed

Dagenais, Emmanuelle; Rouleau, Isabelle; Tremblay, Alexandra; Demers, Mélanie; Roger, Élaine; Jobin, Céline; Duquette, Pierre

2016-11-01

Prospective memory (PM), the ability to remember to do something at the appropriate time in the future, is crucial in everyday life. One way to improve PM performance is to increase the salience of a cue announcing that it is time to act. Multiple sclerosis (MS) patients often report PM failures and there is growing evidence of PM deficits among this population. However, such deficits are poorly characterized and their relation to cognitive status remains unclear. To better understand PM deficits in MS patients, this study investigated the impact of cue salience on PM, and its relation to retrospective memory (RM) and executive deficits. Thirty-nine (39) MS patients were compared to 18 healthy controls on a PM task modulating cue salience during an ongoing general knowledge test. MS patients performed worse than controls on the PM task, regardless of cue salience. MS patients' executive functions contributed significantly to the variance in PM performance, whereas age, education and RM did not. Interestingly, low- and high-executive patients' performance differed when the cue was not salient, but not when it was, suggesting that low-executive MS patients benefited more from cue salience. These findings add to the growing evidence of PM deficits in MS and highlight the contribution of executive functions to certain aspects of PM. In low-executive MS patients, high cue salience improves PM performance by reducing the detection threshold and need for environmental monitoring. Copyright © 2016 Elsevier Inc. All rights reserved.

Attractors of relaxation discrete-time systems with chaotic dynamics on a fast time scale.

PubMed

Maslennikov, Oleg V; Nekorkin, Vladimir I

2016-07-01

In this work, a new type of relaxation systems is considered. Their prominent feature is that they comprise two distinct epochs, one is slow regular motion and another is fast chaotic motion. Unlike traditionally studied slow-fast systems that have smooth manifolds of slow motions in the phase space and fast trajectories between them, in this new type one observes, apart the same geometric objects, areas of transient chaos. Alternating periods of slow regular motions and fast chaotic ones as well as transitions between them result in a specific chaotic attractor with chaos on a fast time scale. We formulate basic properties of such attractors in the framework of discrete-time systems and consider several examples. Finally, we provide an important application of such systems, the neuronal electrical activity in the form of chaotic spike-burst oscillations.

Fast variogram analysis of remotely sensed images in HPC environment

NASA Astrophysics Data System (ADS)

Pesquer, Lluís; Cortés, Anna; Masó, Joan; Pons, Xavier

2013-04-01

Exploring and describing spatial variation of images is one of the main applications of geostatistics to remote sensing. The variogram is a very suitable tool to carry out this spatial pattern analysis. Variogram analysis is composed of two steps: empirical variogram generation and fitting a variogram model. The empirical variogram generation is a very quick procedure for most analyses of irregularly distributed samples, but time consuming increases quite significantly for remotely sensed images, because number of samples (pixels) involved is usually huge (more than 30 million for a Landsat TM scene), basically depending on extension and spatial resolution of images. In several remote sensing applications this type of analysis is repeated for each image, sometimes hundreds of scenes and sometimes for each radiometric band (high number in the case of hyperspectral images) so that there is a need for a fast implementation. In order to reduce this high execution time, we carried out a parallel solution of the variogram analyses. The solution adopted is the master/worker programming paradigm in which the master process distributes and coordinates the tasks executed by the worker processes. The code is written in ANSI-C language, including MPI (Message Passing Interface) as a message-passing library in order to communicate the master with the workers. This solution (ANSI-C + MPI) guarantees portability between different computer platforms. The High Performance Computing (HPC) environment is formed by 32 nodes, each with two Dual Core Intel(R) Xeon (R) 3.0 GHz processors with 12 Gb of RAM, communicated with integrated dual gigabit Ethernet. This IBM cluster is located in the research laboratory of the Computer Architecture and Operating Systems Department of the Universitat Autònoma de Barcelona. The performance results for a 15km x 15km subcene of 198-31 path-row Landsat TM image are shown in table 1. The proximity between empirical speedup behaviour and theoretical linear speedup confirms a suitable parallel design and implementation applied. N Workers Time (s) Speedup 0 2975.03 2 2112.33 1.41 4 1067.45 2.79 8 534.18 5.57 12 357.54 8.32 16 269.00 11.06 20 216.24 13.76 24 186.31 15.97 Furthermore, very similar performance results are obtained for CASI images (hyperspectral and finer spatial resolution than Landsat), showed in table 2, and demonstrating that the distributed load design is not specifically defined and optimized for unique type of images, but it is a flexible design that maintains a good balance and scalability suitable for different range of image dimensions. N Workers Time (s) Speedup 0 5485.03 2 3847.47 1.43 4 1921.62 2.85 8 965.55 5.68 12 644.26 8.51 16 483.40 11.35 20 393.67 13.93 24 347.15 15.80 28 306.33 17.91 32 304.39 18.02 Finally, we conclude that this significant time reduction underlines the utility of distributed environments for processing large amount of data as remotely sensed images.

Analysis of Interactive Graphics Display Equipment for an Automated Photo Interpretation System.

DTIC Science & Technology

1982-06-01

System provides the hardware and software for a range of graphics processor tasks. The IMAGE System employs the RSX- II M real - time operating . system in...One hard copy unit serves up to four work stations. The executive program of the IMAGE system is the DEC RSX- 11 M real - time operating system . In...picture controller. The PDP 11/34 executes programs concurrently under the RSX- I IM real - time operating system . Each graphics program consists of a

Intelligent Rover Execution for Detecting Life in the Atacama Desert

NASA Technical Reports Server (NTRS)

Baskaran, Vijayakumar; Muscettola, Nicola; Rijsman, David; Plaunt, Chris; Fry, Chuck

2006-01-01

On-board supervisory execution is crucial for the deployment of more capable and autonomous remote explorers. Planetary science is considering robotic explorers operating for long periods of time without ground supervision while interacting with a changing and often hostile environment. Effective and robust operations require on-board supervisory control with a high level of awareness of the principles of functioning of the environment and of the numerous internal subsystems that need to be coordinated. We describe an on-board rover executive that was deployed on a rover as past of the "Limits of Life in the Atacama Desert (LITA)" field campaign sponsored by the NASA ASTEP program. The executive was built using the Intelligent Distributed Execution Architecture (IDEA), an execution framework that uses model-based and plan-based supervisory control of its fundamental computational paradigm. We present the results of the third field experiment conducted in the Atacama desert (Chile) in August - October 2005.

The SUCCESS model for laboratory performance and execution of rapid molecular diagnostics in patients with sepsis.

PubMed

Dekmezian, Mhair; Beal, Stacy G; Damashek, Mary Jane; Benavides, Raul; Dhiman, Neelam

2015-04-01

Successful performance and execution of rapid diagnostics in a clinical laboratory hinges heavily on careful validation, accurate and timely communication of results, and real-time quality monitoring. Laboratories must develop strategies to integrate diagnostics with stewardship and evidence-based clinical practice guidelines. We present a collaborative SUCCESS model for execution and monitoring of rapid sepsis diagnostics to facilitate timely treatment. Six months after execution of the Verigene Gram-Positive Blood Culture (BC-GP) and the AdvanDx PNA-FISH assays, data were collected on 579 and 28 episodes of bacteremia and fungemia, respectively. Clinical testing was executed using a SUCCESS model comprising the following components: stewardship, utilization of resources, core strategies, concierge services, education, support, and surveillance. Stewardship needs were identified by evaluating the specialty services benefiting from new testing. Utilization of resources was optimized by reviewing current treatment strategies and antibiogram and formulary options. Core strategies consisted of input from infectious disease leadership, pharmacy, and laboratory staff. Concierge services included automated Micro-eUpdate and physician-friendly actionable reports. Education modules were user-specific, and support was provided through a dedicated 24/7 microbiology hotline. Surveillance was performed by daily audit by the director. Using the SUCCESS model, the turnaround time for the detailed report with actionable guidelines to the physician was ∼3 hours from the time of culture positivity. The overall correlation between rapid methods and culture was 94% (546/579). Discrepant results were predominantly contaminants such as a coagulase-negative staphylococci or viridans streptococci in mixed cultures. SUCCESS is a cost-effective and easily adaptable model for clinical laboratories with limited stewardship resources.

Performance comparison analysis library communication cluster system using merge sort

NASA Astrophysics Data System (ADS)

Wulandari, D. A. R.; Ramadhan, M. E.

2018-04-01

Begins by using a single processor, to increase the speed of computing time, the use of multi-processor was introduced. The second paradigm is known as parallel computing, example cluster. The cluster must have the communication potocol for processing, one of it is message passing Interface (MPI). MPI have many library, both of them OPENMPI and MPICH2. Performance of the cluster machine depend on suitable between performance characters of library communication and characters of the problem so this study aims to analyze the comparative performances libraries in handling parallel computing process. The case study in this research are MPICH2 and OpenMPI. This case research execute sorting’s problem to know the performance of cluster system. The sorting problem use mergesort method. The research method is by implementing OpenMPI and MPICH2 on a Linux-based cluster by using five computer virtual then analyze the performance of the system by different scenario tests and three parameters for to know the performance of MPICH2 and OpenMPI. These performances are execution time, speedup and efficiency. The results of this study showed that the addition of each data size makes OpenMPI and MPICH2 have an average speed-up and efficiency tend to increase but at a large data size decreases. increased data size doesn’t necessarily increased speed up and efficiency but only execution time example in 100000 data size. OpenMPI has a execution time greater than MPICH2 example in 1000 data size average execution time with MPICH2 is 0,009721 and OpenMPI is 0,003895 OpenMPI can customize communication needs.

20 strategies for marketing your managed care plan.

PubMed

Firshein, J

1996-01-01

In today's fiercely competitive managed care marketplace, healthcare executives must find a way to set their plans apart from the competition and build a sufficient customer base. At the same time, they must confront a growing anti-managed care backlash among a wary and confused public. Healthcare executive magazine talked with managed care experts to gather their views on key strategies to help executives meet both of these challenges. Here's what they suggest.

Star ratings. Stars of wonder.

PubMed

Dawes, David

2002-09-12

Analysis of trusts that changed their star-rating over the past two years indicates that a change of chief executive was not a significant factor. The length of time in post and the experience of the chief executive were also insignificant. This has serious implications for the theory behind franchising and the evaluation of franchised trusts. Holding chief executives to account for the organisation's performance within their first 12 months is unlikely to be effective.

Mission Data System Java Edition Version 7

NASA Technical Reports Server (NTRS)

Reinholtz, William K.; Wagner, David A.

2013-01-01

The Mission Data System framework defines closed-loop control system abstractions from State Analysis including interfaces for state variables, goals, estimators, and controllers that can be adapted to implement a goal-oriented control system. The framework further provides an execution environment that includes a goal scheduler, execution engine, and fault monitor that support the expression of goal network activity plans. Using these frameworks, adapters can build a goal-oriented control system where activity coordination is verified before execution begins (plan time), and continually during execution. Plan failures including violations of safety constraints expressed in the plan can be handled through automatic re-planning. This version optimizes a number of key interfaces and features to minimize dependencies, performance overhead, and improve reliability. Fault diagnosis and real-time projection capabilities are incorporated. This version enhances earlier versions primarily through optimizations and quality improvements that raise the technology readiness level. Goals explicitly constrain system states over explicit time intervals to eliminate ambiguity about intent, as compared to command-oriented control that only implies persistent intent until another command is sent. A goal network scheduling and verification process ensures that all goals in the plan are achievable before starting execution. Goal failures at runtime can be detected (including predicted failures) and handled by adapted response logic. Responses can include plan repairs (try an alternate tactic to achieve the same goal), goal shedding, ignoring the fault, cancelling the plan, or safing the system.

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

Nishimura, Takahiro, E-mail: t-nishimura@ist.osaka-u.ac.jp; Fujii, Ryo; Ogura, Yusuke

Molecular logic circuits represent a promising technology for observation and manipulation of biological systems at the molecular level. However, the implementation of molecular logic circuits for temporal and programmable operation remains challenging. In this paper, we demonstrate an optically controllable logic circuit that uses fluorescence resonance energy transfer (FRET) for signaling. The FRET-based signaling process is modulated by both molecular and optical inputs. Based on the distance dependence of FRET, the FRET pathways required to execute molecular logic operations are formed on a DNA nanostructure as a circuit based on its molecular inputs. In addition, the FRET pathways on themore » DNA nanostructure are controlled optically, using photoswitching fluorescent molecules to instruct the execution of the desired operation and the related timings. The behavior of the circuit can thus be controlled using external optical signals. As an example, a molecular logic circuit capable of executing two different logic operations was studied. The circuit contains functional DNAs and a DNA scaffold to construct two FRET routes for executing Input 1 AND Input 2 and Input 1 AND NOT Input 3 operations on molecular inputs. The circuit produced the correct outputs with all possible combinations of the inputs by following the light signals. Moreover, the operation execution timings were controlled based on light irradiation and the circuit responded to time-dependent inputs. The experimental results demonstrate that the circuit changes the output for the required operations following the input of temporal light signals.« less

Autonomous Real Time Requirements Tracing

NASA Technical Reports Server (NTRS)

Plattsmier, George I.; Stetson, Howard K.

2014-01-01

One of the more challenging aspects of software development is the ability to verify and validate the functional software requirements dictated by the Software Requirements Specification (SRS) and the Software Detail Design (SDD). Insuring the software has achieved the intended requirements is the responsibility of the Software Quality team and the Software Test team. The utilization of Timeliner-TLX(sup TM) Auto-Procedures for relocating ground operations positions to ISS automated on-board operations has begun the transition that would be required for manned deep space missions with minimal crew requirements. This transition also moves the auto-procedures from the procedure realm into the flight software arena and as such the operational requirements and testing will be more structured and rigorous. The autoprocedures would be required to meet NASA software standards as specified in the Software Safety Standard (NASASTD- 8719), the Software Engineering Requirements (NPR 7150), the Software Assurance Standard (NASA-STD-8739) and also the Human Rating Requirements (NPR-8705). The Autonomous Fluid Transfer System (AFTS) test-bed utilizes the Timeliner-TLX(sup TM) Language for development of autonomous command and control software. The Timeliner- TLX(sup TM) system has the unique feature of providing the current line of the statement in execution during real-time execution of the software. The feature of execution line number internal reporting unlocks the capability of monitoring the execution autonomously by use of a companion Timeliner-TLX(sup TM) sequence as the line number reporting is embedded inside the Timeliner-TLX(sup TM) execution engine. This negates I/O processing of this type data as the line number status of executing sequences is built-in as a function reference. This paper will outline the design and capabilities of the AFTS Autonomous Requirements Tracker, which traces and logs SRS requirements as they are being met during real-time execution of the targeted system. It is envisioned that real time requirements tracing will greatly assist the movement of autoprocedures to flight software enhancing the software assurance of auto-procedures and also their acceptance as reliable commanders

Autonomous Real Time Requirements Tracing

NASA Technical Reports Server (NTRS)

Plattsmier, George; Stetson, Howard

2014-01-01

One of the more challenging aspects of software development is the ability to verify and validate the functional software requirements dictated by the Software Requirements Specification (SRS) and the Software Detail Design (SDD). Insuring the software has achieved the intended requirements is the responsibility of the Software Quality team and the Software Test team. The utilization of Timeliner-TLX(sup TM) Auto- Procedures for relocating ground operations positions to ISS automated on-board operations has begun the transition that would be required for manned deep space missions with minimal crew requirements. This transition also moves the auto-procedures from the procedure realm into the flight software arena and as such the operational requirements and testing will be more structured and rigorous. The autoprocedures would be required to meet NASA software standards as specified in the Software Safety Standard (NASASTD- 8719), the Software Engineering Requirements (NPR 7150), the Software Assurance Standard (NASA-STD-8739) and also the Human Rating Requirements (NPR-8705). The Autonomous Fluid Transfer System (AFTS) test-bed utilizes the Timeliner-TLX(sup TM) Language for development of autonomous command and control software. The Timeliner-TLX(sup TM) system has the unique feature of providing the current line of the statement in execution during real-time execution of the software. The feature of execution line number internal reporting unlocks the capability of monitoring the execution autonomously by use of a companion Timeliner-TLX(sup TM) sequence as the line number reporting is embedded inside the Timeliner-TLX(sup TM) execution engine. This negates I/O processing of this type data as the line number status of executing sequences is built-in as a function reference. This paper will outline the design and capabilities of the AFTS Autonomous Requirements Tracker, which traces and logs SRS requirements as they are being met during real-time execution of the targeted system. It is envisioned that real time requirements tracing will greatly assist the movement of autoprocedures to flight software enhancing the software assurance of auto-procedures and also their acceptance as reliable commanders.

The benefits of Tai Chi and brisk walking for cognitive function and fitness in older adults

PubMed Central

Ji, Zhiguang; Feng, Tian; Liu, Xiaolei; You, Yihong; Meng, Fanying; Wang, Ruoqing; Lu, Jialing

2017-01-01

The purpose of this study was to investigate the benefits of exercises with different cognitive demands for cognitive functions (Executive and non-Executive) in healthy older adults. A cross-sectional design was adopted. In total, 84 healthy older adults were enrolled in the study. They were categorized into the Tai Chi group (TG), the brisk walking group (BG) or the control group (CG). Each participant performed the Stroop task and a digit comparison task. The Stroop task included the following three conditions: a naming condition, an inhibition condition and an executive condition. There were two experimental conditions in the digit comparison task: the non-delay condition and the delay condition. The results indicated that participants of the TG and BG revealed significant better performance than the CG in the executive condition of cognitive tasks and fitness. There was no significant difference of reaction time (RT) and accuracy rate in the inhibition and delay conditions of cognitive tasks and fitness between the TG and BG. The TG showed shorter reaction time in the naming and the executive conditions, and more accurate in the inhibition conditions than the BG. These findings demonstrated that regular participation in brisk walking and Tai Chi have significant beneficial effects on executive function and fitness. However, due to the high cognitive demands of the exercise, Tai Chi benefit cognitive functions (Executive and non-Executive) in older adults more than brisk walking does. Further studies should research the underlying mechanisms at the behavioural and neuroelectric levels, providing more evidence to explain the effect of high-cognitive demands exercise on different processing levels of cognition. PMID:29062610