Biases in spatial bisection induced by viewing male and female faces.

Science.gov (United States)

Cattaneo, Zaira; Schiavi, Susanna; Lega, Carlotta; Renzi, Chiara; Tagliaferri, Matteo; Boehringer, Jana; Carbon, Claus-Christian; Vecchi, Tomaso

2014-01-01

Research on visual attention triggered by face gender is still relatively sparse. In the present study, three experiments are reported in which male and female participants were required to estimate the midpoint of a line (i.e., the "line bisection task"): at each end of the line a face was presented. Depending on the experimental condition, faces could be of the same gender (i.e., two males or two females) or the opposite gender. Experiments 1 and 2 converged in showing that when a male face was presented at the right and a female face at the left endpoint of the line, a clear rightward bias emerged compared to the other experimental conditions, indicating that male faces captured attention more than female faces. Importantly, male faces used across Experiments 1 and 2 were rated as more threatening than female faces, suggesting that perceived level of threat may have been responsible for the observed bias toward the male face. Experiment 3 corroborated this hypothesis by finding an attentional bias toward the male face with high threat (angry) faces but not with low threat (smiling) faces.

Further tests of the Scalar Expectancy Theory (SET) and the Learning-to-Time (LeT) model in a temporal bisection task.

Science.gov (United States)

Machado, Armando; Arantes, Joana

2006-06-01

To contrast two models of timing, Scalar Expectancy Theory (SET) and Learning to Time (LeT), pigeons were exposed to a double temporal bisection procedure. On half of the trials, they learned to choose a red key after a 1s signal and a green key after a 4s signal; on the other half of the trials, they learned to choose a blue key after a 4-s signal and a yellow key after a 16-s signal. This was Phase A of an ABA design. On Phase B, the pigeons were divided into two groups and exposed to a new bisection task in which the signals ranged from 1 to 16s and the choice keys were blue and green. One group was reinforced for choosing blue after 1-s signals and green after 16-s signals and the other group was reinforced for the opposite mapping (green after 1-s signals and blue after 16-s signals). Whereas SET predicted no differences between the groups, LeT predicted that the former group would learn the new discrimination faster than the latter group. The results were consistent with LeT. Finally, the pigeons returned to Phase A. Only LeT made specific predictions regarding the reacquisition of the four temporal discriminations. These predictions were only partly consistent with the results.

Markov bridges, bisection and variance reduction

DEFF Research Database (Denmark)

Asmussen, Søren; Hobolth, Asger

. In this paper we firstly consider the problem of generating sample paths from a continuous-time Markov chain conditioned on the endpoints using a new algorithm based on the idea of bisection. Secondly we study the potential of the bisection algorithm for variance reduction. In particular, examples are presented......Time-continuous Markov jump processes is a popular modelling tool in disciplines ranging from computational finance and operations research to human genetics and genomics. The data is often sampled at discrete points in time, and it can be useful to simulate sample paths between the datapoints...

What makes a word so attractive? Disclosing the urge to read while bisecting.

Science.gov (United States)

Girelli, Luisa; Previtali, Paola; Arduino, Lisa S

2018-04-22

Expert readers have been repeatedly reported to misperceive the centre of visual stimuli, shifting systematically to the left the bisection of any lines (pseudoneglect) while showing a cross-over effect while bisecting different types of orthographic strings (Arduino et al., 2010, Neuropsychologia, 48, 2140). This difference has been attributed to asymmetrical allocation of attention that visuo-verbal material receives when lexical access occurs (e.g., Fischer, 2004, Cognitive Brain Research, 4, 163). The aim of this study was to further examine which visual features guide recognition of potentially orthographic materials. To disentangle the role of orthography, heterogeneity, and visuo-perceptual discreteness, we presented Italian unimpaired adults with four experiments exploiting the bisection paradigm. The results showed that a cross-over effect emerges in most discrete strings, especially when their internal structure, that is being composed of heterogeneous elements, is suggestive of orthographically relevant material. Interestingly, the cross-over effect systematically characterized the processing of letter strings (Experiment 2) and words (Experiments 3 and 4), whether visually discrete or not. Overall, this pattern of results suggests that neither discreteness nor heterogeneity per se are responsible for activating visual scanning mechanisms implied in text exploration, although both contribute to increasing the chance of a visual stimulus undergoing a perceptual analysis dedicated to pre-lexical processing. © 2018 The British Psychological Society.

Bisecting real and fake body parts: effects of prism adaptation after right brain damage

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Nadia eBolognini

2012-06-01

Full Text Available The representation of body parts holds a special status in the brain, due to their prototypical shape and the contribution of multisensory (visual and somatosensory-proprioceptive information. In a previous study (Sposito et al., 2010, we showed that patients with left unilateral spatial neglect exhibit a rightward bias in setting the mid-point of their left forearm, which becomes larger when bisecting a cylindrical object comparable in size. This body part advantage, found also in control participants, suggests partly different processes for computing the extent of body parts and objects. In this study we tested 16 right-brain-damaged patients, and 10 unimpaired participants, on a manual bisection task of their own (real left forearm, or a size-matched fake forearm. We then explored the effects of adaptation to rightward displacing prism exposure, which brings about leftward aftereffects. We found that all participants showed prism adaptation and aftereffects, with right-brain-damaged patients exhibiting a reduction of the rightward bias for both real and fake forearm, with no overall differences between them. Second, correlation analyses highlighted the role of visual and proprioceptive information for the metrics of body parts. Third, single-patient analyses showed dissociations between real and fake forearm bisections, and the effects of prism adaptation, as well as a more frequent impairment with fake body parts. In sum, the rightward bias shown by right-brain-damaged patients in bisecting body parts is reduced by prism exposure, as other components of the neglect syndrome; discrete spatial representations for real and fake body parts, for which visual and proprioceptive codes play different roles, are likely to exist. Multisensory information seems to render self bodily segments more resistant to the disruption brought about by right-hemisphere injury.

Comparison of Scalar Expectancy Theory (SET) and the Learning-to-Time (LeT) model in a successive temporal bisection task.

Science.gov (United States)

Arantes, Joana

2008-06-01

The present research tested the generality of the "context effect" previously reported in experiments using temporal double bisection tasks [e.g., Arantes, J., Machado, A. Context effects in a temporal discrimination task: Further tests of the Scalar Expectancy Theory and Learning-to-Time models. J. Exp. Anal. Behav., in press]. Pigeons learned two temporal discriminations in which all the stimuli appear successively: 1s (red) vs. 4s (green) and 4s (blue) vs. 16s (yellow). Then, two tests were conducted to compare predictions of two timing models, Scalar Expectancy Theory (SET) and the Learning-to-Time (LeT) model. In one test, two psychometric functions were obtained by presenting pigeons with intermediate signal durations (1-4s and 4-16s). Results were mixed. In the critical test, pigeons were exposed to signals ranging from 1 to 16s and followed by the green or the blue key. Whereas SET predicted that the relative response rate to each of these keys should be independent of the signal duration, LeT predicted that the relative response rate to the green key (compared with the blue key) should increase with the signal duration. Results were consistent with LeT's predictions, showing that the context effect is obtained even when subjects do not need to make a choice between two keys presented simultaneously.

Stimulus- and state-dependence of systematic bias in spatial attention: additive effects of stimulus-size and time-on-task.

Science.gov (United States)

Benwell, Christopher S Y; Harvey, Monika; Gardner, Stephanie; Thut, Gregor

2013-03-01

Systematic biases in spatial attention are a common finding. In the general population, a systematic leftward bias is typically observed (pseudoneglect), possibly as a consequence of right hemisphere dominance for visuospatial attention. However, this leftward bias can cross-over to a systematic rightward bias with changes in stimulus and state factors (such as line length and arousal). The processes governing these changes are still unknown. Here we tested models of spatial attention as to their ability to account for these effects. To this end, we experimentally manipulated both stimulus and state factors, while healthy participants performed a computerized version of a landmark task. State was manipulated by time-on-task (>1 h) leading to increased fatigue and a reliable left- to rightward shift in spatial bias. Stimulus was manipulated by presenting either long or short lines which was associated with a shift of subjective midpoint from a reliable leftward bias for long to a more rightward bias for short lines. Importantly, we found time-on-task and line length effects to be additive suggesting a common denominator for line bisection across all conditions, which is in disagreement with models that assume that bisection decisions in long and short lines are governed by distinct processes (Magnitude estimation vs Global/local distinction). Our findings emphasize the dynamic rather than static nature of spatial biases in midline judgement. They are best captured by theories of spatial attention positing that spatial bias is flexibly modulated, and subject to inter-hemispheric balance which can change over time or conditions to accommodate task demands or reflect fatigue. Copyright © 2012 Elsevier Ltd. All rights reserved.

Comparison of relationship between antral floor and maxillary root apex in bisecting and panoramic techniques

International Nuclear Information System (INIS)

You, Dong Soo; Kim, In Soo

1986-01-01

This study was performed to compare the difference of intraoral bisecting and panoramic techniques in evaluating the relationship of antral floor and maxillary roots. The vertical distances form maxillary root apices to antral floor were measured on both orthopantomograms and bisecting projections obtained form fifth subjects. The results were as follows: 1. Tooth lengths measured on orthopantomogram were larger than on bisecting projection and the magnification ratios were 1.08-1.17. 2. The dimensions from maxillary root apices to antral floor measured on orthopantomogram were larger than on bisecting projection. 3. The above results held true regardless of age and sex.

Image of a line is not shrunk but neglected. Absence of crossover in unilateral spatial neglect.

Science.gov (United States)

Ishiai, Sumio; Koyama, Yasumasa; Nakano, Naomi; Seki, Keiko; Nishida, Yoichiro; Hayashi, Kazuko

2004-01-01

Patients with left unilateral spatial neglect following right hemisphere lesions usually err rightward when bisecting a horizontal line. For very short lines (e.g. 25 mm), however, leftward errors or seemingly 'right' neglect is often observed. To explain this paradox of crossover in the direction of errors, rather complicated models have been introduced as to the distribution of attention. Neglect may be hypothesized to occur in representational process of a line or estimation of the midpoint on the formed image, or both. We devised a line image task using a computer display with a touch panel and approached the representational image of a line to be bisected. Three patients with typical left neglect were presented with a line and forced to see its whole extent with cueing to the left endpoint. After disappearance of the line, they pointed to the right endpoint, the left endpoint, or the subjective midpoint according to their representational image. The line image between the reproduced right and left endpoints was appropriately formed for the 200 mm lines. However, the images for the shorter 25 and 100 mm lines were longer than the physical lengths with overextension to the left side. These results proved the context effect that short lines may be perceived longer when they are presented in combination with longer lines. One of our patients had an extensive lesion that involved the frontal, temporal, and parietal lobes, and the other two had a lesion restricted to the posterior right hemisphere. The image for a fully perceived line may be represented far enough into left space even when left neglect occurs after a lesion that involves the right parietal lobe. The patients with neglect placed the subjective midpoint rightward from the centre of the stimulus line for the 100 and 200 mm lines and leftward for the 25 mm lines. This crossover of bisection errors disappeared when the displacement of the subjective midpoint was measured from the centre of the

The Inhibiting Bisection Problem

Energy Technology Data Exchange (ETDEWEB)

Pinar, Ali; Fogel, Yonatan; Lesieutre, Bernard

2006-12-18

Given a graph where each vertex is assigned a generation orconsumption volume, we try to bisect the graph so that each part has asignificant generation/consumption mismatch, and the cutsize of thebisection is small. Our motivation comes from the vulnerability analysisof distribution systems such as the electric power system. We show thatthe constrained version of the problem, where we place either the cutsizeor the mismatch significance as a constraint and optimize the other, isNP-complete, and provide an integer programming formulation. We alsopropose an alternative relaxed formulation, which can trade-off betweenthe two objectives and show that the alternative formulation of theproblem can be solved in polynomial time by a maximum flow solver. Ourexperiments with benchmark electric power systems validate theeffectiveness of our methods.

Integrating Robot Task Planning into Off-Line Programming Systems

DEFF Research Database (Denmark)

Sun, Hongyan; Kroszynski, Uri

1988-01-01

a system architecture for integrated robot task planning. It identifies and describes the components considered necessary for implementation. The focus is on functionality of these elements as well as on the information flow. A pilot implementation of such an integrated system architecture for a robot......The addition of robot task planning in off-line programming systems aims at improving the capability of current state-of-the-art commercially available off-line programming systems, by integrating modeling, task planning, programming and simulation together under one platform. This article proposes...... assembly task is discussed....

Oral contraceptive therapy modulates hemispheric asymmetry in spatial attention.

Science.gov (United States)

Cicinelli, Ettore; De Tommaso, Marina; Cianci, Antonio; Colacurci, Nicola; Rella, Leonarda; Loiudice, Luisa; Cicinelli, Maria Vittoria; Livrea, Paolo

2011-12-01

Functional cerebral asymmetries (FCAs) are known to fluctuate across the menstrual cycle. The visual line-bisection task administered to normally cycling women showed different patterns of the interhemispheric interactions during menses and the midluteal cycle phase. However, the contribution of estrogens and progestins hormones to this phenomenon is still unclear. The aim of our study was to show a variation of FCAs in women administered oral contraceptives (OCs) using the visual line-bisection task. Visual line-bisection task with three horizontal lines was administered to 36 healthy women taking a 21-day OC. Twenty-nine patients were right handed. The task was administered during OC intake (day 10) and at the end of the pill-free period. The right-handed women showed a significant leftward bias of veridical center on the first and third lines during OC intake compared with an opposite rightward bias during the pill-free period. The same phenomenon of contralateral deviation was observed in left-handed women on day 10 of OC intake. The results of this study confirm a hormonal modulation on interhemispheric interaction and suggest that OCs may improve the interhemispheric interaction reducing FCAs compared with the low hormone level period. This opens new insights in OC prescription and choice of administration schedule in order to improve cognitive performances. Copyright © 2011 Elsevier Inc. All rights reserved.

The Task Manager for the LHCb On-Line Farm

CERN Document Server

Bonifazi, F; Carbone, A; Galli, D; Gregori, D; Marconi, U; Peco, G; Vagnoni, V

2004-01-01

The Task Manager is a utility to start, stop and list processes on the on-line farm. Each process started by the Task Manager has a string environment variable set, named UTGID (User defined unique Thread Group Identifier) which allows to identify the process. The Task Manager uses the UTGID to list the running processes and to identify the processes to be stopped. It has also the ability to start a process using a particular user name and to set the scheduler type and the priority for the process itself. The Task Manager package includes a Linux DIM server (tmSrv), four Linux command line DIM clients (tmStart, tmLs, tmKill and tmStop) and a JCOP (Joint Control Project) PVSS client.

Orientation of X Lines in Asymmetric Magnetic Reconnection-Mass Ratio Dependency

Science.gov (United States)

Liu, Yi-Hsin; Hesse, M.; Kuznetsova, M.

2015-01-01

Using fully kinetic simulations, we study the X line orientation of magnetic reconnection in an asymmetric configuration. A spatially localized perturbation is employed to induce a single X line, which has sufficient freedom to choose its orientation in three-dimensional systems. The effect of ion to electron mass ratio is investigated, and the X line appears to bisect the magnetic shear angle across the current sheet in the large mass ratio limit. The orientation can generally be deduced by scanning through the corresponding 2-D simulations to find the reconnection plane that maximizes the peak reconnection electric field. The deviation from the bisection angle in the lower mass ratio limit is consistent with the orientation shift of the most unstable linear tearing mode in an electron-scale current sheet.

Putts that get missed on the right: investigating lateralized attentional biases and the nature of putting errors in golf.

Science.gov (United States)

Roberts, Ross; Turnbull, Oliver H

2010-02-01

Although the effects of lateral biases in visual attention ("pseudoneglect") have been examined in real-world settings, this phenomenon has yet to be considered within the realm of sporting performance. In the present study, we investigated the effects of pseudoneglect on putting errors in golf. Novice golfers (n = 30) performed 90 putting trials followed by a series of pseudoneglect tasks: requiring participants to bisect lines manually and with a biomechanical bisection tool. All pseudoneglect measures were performed with both the left and right hands. Results demonstrated a leftward bias for all the pseudoneglect tasks, and a rightward bias for putting error. Moreover, the results revealed that individuals who bisected lines to the left on the Bisection Tool (the typical class of pseudoneglect error for humans) with the left hand (the hand that typically produces the greatest pseudoneglect bias) displayed significantly smaller rightward putting errors. Moreover, these individuals also holed more putts. No other pseudoneglect tasks were shown to impact on putting performance. Our findings suggest that lateralized attentional biases have a significant effect on sport performance; they appear to influence a wide range of precision-based sports (e.g. shooting, archery). Findings are also discussed in terms of the processes that are likely to be involved in this effect.

Cognitive abilities required in time judgment depending on the temporal tasks used: A comparison of children and adults.

Science.gov (United States)

Droit-Volet, S; Wearden, J H; Zélanti, P S

2015-01-01

The aim of this study was to examine age-related differences in time judgments during childhood as a function of the temporal task used. Children aged 5 and 8 years, as well as adults, were submitted to 3 temporal tasks (bisection, generalization and reproduction) with short (0.4/0.8 s) and long durations (8/16 s). Furthermore, their cognitive capacities in terms of working memory, attentional control, and processing speed were assessed by a wide battery of neuropsychological tests. The results showed that the age-related differences in time judgment were greater in the reproduction task than in the temporal discrimination tasks. This task was indeed more demanding in terms of working memory and information processing speed. In addition, the bisection task appeared to be easier for children than the generalization task, whereas these 2 tasks were similar for the adults, although the generalization task required more attention to be paid to the processing of durations. Our study thus demonstrates that it is important to understand the different cognitive processes involved in time judgment as a function of the temporal tasks used before venturing to draw conclusions about the development of time perception capabilities.

Relative versus Absolute Stimulus Control in the Temporal Bisection Task

Science.gov (United States)

de Carvalho, Marilia Pinhiero; Machado, Armando

2012-01-01

When subjects learn to associate two sample durations with two comparison keys, do they learn to associate the keys with the short and long samples (relational hypothesis), or with the specific sample durations (absolute hypothesis)? We exposed 16 pigeons to an ABA design in which phases A and B corresponded to tasks using samples of 1 s and 4 s,…

The Effects of Pre-Task, On-Line, and Both Pre-Task and On-Line Planning on Fluency, Complexity, and Accuracy--The Case of Iranian EFL Learners' Written Production

Science.gov (United States)

Piri, Faramarz; Barati, Hossein; Ketabi, Saeed

2012-01-01

Previous studies on the effect of planning on language production have revealed that planning does have a positive effect on language performance in terms of fluency, complexity, and accuracy. The present study was an attempt to investigate the effects of pre-task, on-line, and both pre-task and on-line planning on fluency, accuracy, and…

PERBANDINGAN KEEFISIENAN METODE NEWTON-RAPHSON, METODE SECANT, DAN METODE BISECTION DALAM MENGESTIMASI IMPLIED VOLATILITIES SAHAM

Directory of Open Access Journals (Sweden)

IDA AYU EGA RAHAYUNI

2016-01-01

Full Text Available Black-Scholes model suggests that volatility is constant or fixed during the life time of the option certainly known. However, this does not fit with what happen in the real market. Therefore, the volatility has to be estimated. Implied Volatility is the etimated volatility from a market mechanism that is considered as a reasonable way to assess the volatility's value. This study was aimed to compare the Newton-Raphson, Secant, and Bisection method, in estimating the stock volatility value of PT Telkom Indonesia Tbk (TLK. It found that the three methods have the same Implied Volatilities, where Newton-Raphson method gained roots more rapidly than the two others, and it has the smallest relative error greater than Secant and Bisection methods.

Pedagogical directions to design and support collaborative knowledge building on-line tasks

Directory of Open Access Journals (Sweden)

Ingrid Noguera Fructuoso

2013-02-01

Full Text Available 0 0 1 187 1034 USAL 8 2 1219 14.0 Normal 0 21 false false false ES JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:Calibri; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-ansi-language:ES; mso-fareast-language:EN-US;} Research on Computer-Supported Collaborative Learning (CSCL demonstrates that proposing that students work in groups does not improve their learning or increase their motivation. It is essential to design appropriate learning tasks and suitable pedagogical and technological support. The aim of this research is to identify pedagogical directions to design and support collaborative knowledge building tasks in on-line education. We conducted a case study at the Open University of Catalonia where we carried out two experiments: the first focusing on how teachers design and support collaborative on-line learning tasks and, the second, based on the control exerted over the tasks. As a result of the investigation we characterize the type of tasks that promote collaborative knowledge building, the teachers’ role and functions supporting these types of tasks, and we identify different stages in task regulation. Based on these results, we propose pedagogical directions to design and support collaborative on-line tasks divided into 4 stages: 1 Task design and individual preparation, 2 Task organization and group negotiation, 3 Task performance and collaborative knowledge building, and 4 Critical evaluation.

Early Numerical Competence and Number Line Task Performance in Kindergarteners

Science.gov (United States)

Fanari, Rachele; Meloni, Carla; Massidda, Davide

2017-01-01

This work aims to evaluate the relationship between early numerical competence in kindergarteners and their numerical representations as measured by the number line task (NLT). Thirty-four 5-year-old children participated in the study. Children's early performance on symbolic and non-symbolic numerical tasks was considered to determine which was a…

Projecting one’s own spatial bias onto others during a theory-of-mind task

Science.gov (United States)

Bio, Branden J.; Webb, Taylor W.; Graziano, Michael S. A.

2018-01-01

Many people show a left-right bias in visual processing. We measured spatial bias in neurotypical participants using a variant of the line bisection task. In the same participants, we measured performance in a social cognition task. This theory-of-mind task measured whether each participant had a processing-speed bias toward the right of, or left of, a cartoon agent about which the participant was thinking. Crucially, the cartoon was rotated such that what was left and right with respect to the cartoon was up and down with respect to the participant. Thus, a person’s own left-right bias could not align directly onto left and right with respect to the cartoon head. Performance on the two tasks was significantly correlated. People who had a natural bias toward processing their own left side of space were quicker to process how the cartoon might think about objects to the left side of its face, and likewise for a rightward bias. One possible interpretation of these results is that the act of processing one’s own personal space shares some of the same underlying mechanisms as the social cognitive act of reconstructing someone else’s processing of their space. PMID:29339513

Separated-orbit bisected energy-recovered linear accelerator

Science.gov (United States)

Douglas, David R.

2015-09-01

A separated-orbit bisected energy-recovered linear accelerator apparatus and method. The accelerator includes a first linac, a second linac, and a plurality of arcs of differing path lengths, including a plurality of up arcs, a plurality of downgoing arcs, and a full energy arc providing a path independent of the up arcs and downgoing arcs. The up arcs have a path length that is substantially a multiple of the RF wavelength and the full energy arc includes a path length that is substantially an odd half-integer multiple of the RF wavelength. Operation of the accelerator includes accelerating the beam utilizing the linacs and up arcs until the beam is at full energy, at full energy executing a full recirculation to the second linac using a path length that is substantially an odd half-integer of the RF wavelength, and then decelerating the beam using the linacs and downgoing arcs.

Visual Distraction: An Altered Aiming Spatial Response in Dementia

Directory of Open Access Journals (Sweden)

Elizabeth E. Galletta

2012-06-01

Full Text Available Background/Aims: Healthy individuals demonstrate leftward bias on visuospatial tasks such as line bisection, which has been attributed to right brain dominance. We investigated whether this asymmetry occurred in patients with probable dementia of the Alzheimer type (pAD which is associated with neurodegenerative changes affecting temporoparietal regions. Methods: Subjects with pAD and matched controls performed a line bisection task in near and far space under conditions of no distraction, left-sided visual distraction and right-sided visual distraction. Results: Participants with pAD manifested different motor-preparatory ‘aiming’ spatial bias than matched controls. There were significantly greater rightward ‘aiming’ motor-intentional errors both without distraction and with right-sided distraction. Conclusion: ‘Aiming’ motor-preparatory brain activity may be induced by distraction in pAD subjects as compared to typical visual-motor function in controls.

The role of the right superior temporal gyrus in stimulus-centered spatial processing.

Science.gov (United States)

Shah-Basak, Priyanka P; Chen, Peii; Caulfield, Kevin; Medina, Jared; Hamilton, Roy H

2018-05-01

Although emerging neuropsychological evidence supports the involvement of temporal areas, and in particular the right superior temporal gyrus (STG), in allocentric neglect deficits, the role of STG in healthy spatial processing remains elusive. While several functional brain imaging studies have demonstrated involvement of the STG in tasks involving explicit stimulus-centered judgments, prior rTMS studies targeting the right STG did not find the expected neglect-like rightward bias in size judgments using the conventional landmark task. The objective of the current study was to investigate whether disruption of the right STG using inhibitory repetitive transcranial magnetic stimulation (rTMS) could impact stimulus-centered, allocentric spatial processing in healthy individuals. A lateralized version of the landmark task was developed to accentuate the dissociation between viewer-centered and stimulus-centered reference frames. We predicted that inhibiting activity in the right STG would decrease accuracy because of induced rightward bias centered on the line stimulus irrespective of its viewer-centered or egocentric locations. Eleven healthy, right-handed adults underwent the lateralized landmark task. After viewing each stimulus, participants had to judge whether the line was bisected, or whether the left (left-long trials) or the right segment (right-long trials) of the line was longer. Participants repeated the task before (pre-rTMS) and after (post-rTMS) receiving 20 min of 1 Hz rTMS over the right STG, the right supramarginal gyrus (SMG), and the vertex (a control site) during three separate visits. Linear mixed models for binomial data were generated with either accuracy or judgment errors as dependent variables, to compare 1) performance across trial types (bisection, non-bisection), and 2) pre- vs. post-rTMS performance between the vertex and the STG and the vertex and the SMG. Line eccentricity (z = 4.31, p right-long type by 10.7% on bisection

The amusic brain: lost in music, but not in space.

Directory of Open Access Journals (Sweden)

Barbara Tillmann

Full Text Available Congenital amusia is a neurogenetic disorder of music processing that is currently ascribed to a deficit in pitch processing. A recent study challenges this view and claims the disorder might arise as a consequence of a general spatial-processing deficit. Here, we assessed spatial processing abilities in two independent samples of individuals with congenital amusia by using line bisection tasks (Experiment 1 and a mental rotation task (Experiment 2. Both amusics and controls showed the classical spatial effects on bisection performance and on mental rotation performance, and amusics and controls did not differ from each other. These results indicate that the neurocognitive impairment of congenital amusia does not affect the processing of space.

On numerical regularity of the face-to-face longest-edge bisection algorithm for tetrahedral partitions

Czech Academy of Sciences Publication Activity Database

Hannukainen, A.; Korotov, S.; Křížek, Michal

2014-01-01

Roč. 90, Part A (2014), s. 34-41 ISSN 0167-6423 R&D Projects: GA ČR GA14-02067S Institutional support: RVO:67985840 Keywords : bisection algorithm * conforming finite element method * regular family of partitions Subject RIV: BA - General Mathematics Impact factor: 0.715, year: 2014 http://www.sciencedirect.com/science/article/pii/S0167642313001226

Lucky numbers: spatial neglect affects physical, but not representational, choices in a lotto task.

Science.gov (United States)

Loetscher, Tobias; Nicholls, Michael E R; Towse, John N; Bradshaw, John L; Brugger, Peter

2010-05-01

Spatial neglect can be characterized by a "magnetic attraction" towards the right side of a visual stimulus array and a selection of stimuli from that hemispace. This study examined whether these distinctive characteristics in visuo-motor space are also evident in representational number space. Given that numbers are thought to be represented along a left-to-right oriented mental number line, an affinity for the spontaneous selection of larger numbers was anticipated for neglect patients. Contrary to this expectation, neglect patients (n=20) picked a similar range of numbers compared to controls (n=17) when generating a number between 1000 and 10,000 and when playing an imaginary lottery game. There was, however, a positive correlation between the biases for the imaginary lottery, number generation and a number bisection task - demonstrating that exploration asymmetries along the mental number line are consistent within individuals across tasks. Some of the patients selected smaller numbers in all of these tasks, confirming reports of dissociations between physical and numerical-representational forms of neglect. Conversely, only four (20%) of the patients could reliably be classified as demonstrating a neglect in number space. When filling out a physical lottery ticket, the neglect patients showed the expected bias towards picking numbers placed on the right-hand side of the ticket. These results demonstrate that the magnetic attraction towards the right side of mental representations is rather weak and that representational forms of neglect only occasionally co-exist with neglect in physical space. Copyright 2009 Elsevier Srl. All rights reserved.

Right hemisphere control of visuospatial attention in near space.

Science.gov (United States)

Longo, Matthew R; Trippier, Sarah; Vagnoni, Eleonora; Lourenco, Stella F

2015-04-01

Traditionally, the right cerebral hemisphere has been considered to be specialized for spatial attention and orienting. A large body of research has demonstrated dissociable representations of the near space immediately surrounding the body and the more distance far space. In this study, we investigated whether right hemisphere activations commonly reported for tasks involving spatial attention (such as the line bisection and landmark tasks) are specific to stimuli presented in near space. In separate blocks of trials, participants judged either whether a vertical transector was to the left or right of the centre of a line (landmark task) or whether the line was red or blue (colour task). Stimuli were seen from four distances (30, 60, 90, 120 cm). We used EEG to measure an ERP component (the 'line-bisection effect') specific to the direction of spatial attention (i.e., landmark minus colour). Consistent with previous results, spatial attention produced a right-lateralized negativity over occipito-parietal channels. The magnitude of this negativity was inversely related to viewing distance, being largest in near space and reduced in far space. These results suggest that the right occipito-temporal cortex may be specialized not just for the orientation of spatial attention generally, but specifically for orienting attention in the near space immediately surrounding the body. Copyright © 2014 Elsevier Ltd. All rights reserved.

Reduced Pseudoneglect for Physical Space, but Not Mental Representations of Space, for Adults with Autistic Traits

Science.gov (United States)

English, Michael C.; Maybery, Murray T.; Visser, Troy A.

2017-01-01

Neurotypical individuals display a leftward attentional bias, called pseudoneglect, for physical space (e.g. landmark task) and mental representations of space (e.g. mental number line bisection). However, leftward bias is reduced in autistic individuals viewing faces, and neurotypical individuals with autistic traits viewing "greyscale"…

Neglect Impairs Explicit Processing of the Mental Number Line

Science.gov (United States)

Zorzi, Marco; Bonato, Mario; Treccani, Barbara; Scalambrin, Giovanni; Marenzi, Roberto; Priftis, Konstantinos

2012-01-01

Converging evidence suggests that visuospatial attention plays a pivotal role in numerical processing, especially when the task involves the manipulation of numerical magnitudes. Visuospatial neglect impairs contralesional attentional orienting not only in perceptual but also in numerical space. Indeed, patients with left neglect show a bias toward larger numbers when mentally bisecting a numerical interval, as if they were neglecting its leftmost part. In contrast, their performance in parity judgments is unbiased, suggesting a dissociation between explicit and implicit processing of numerical magnitude. Here we further investigate the consequences of these visuospatial attention impairments on numerical processing and their interaction with task demands. Patients with right hemisphere damage, with and without left neglect, were administered both a number comparison and a parity judgment task that had identical stimuli and response requirements. Neglect patients’ performance was normal in the parity task, when processing of numerical magnitude was implicit, whereas they showed characteristic biases in the number comparison task, when access to numerical magnitude was explicit. Compared to patients without neglect, they showed an asymmetric distance effect, with slowing of the number immediately smaller than (i.e., to the left of) the reference and a stronger SNARC effect, particularly for large numbers. The latter might index an exaggerated effect of number-space compatibility after ipsilesional (i.e., rightward) orienting in number space. Thus, the effect of neglect on the explicit processing of numerical magnitude can be understood in terms of both a failure to orient to smaller (i.e., contralesional) magnitudes and a difficulty to disengage from larger (i.e., ipsilesional) magnitudes on the number line, which resembles the disrupted pattern of attention orienting in visual space. PMID:22661935

Surface wave velocity tracking by bisection method

International Nuclear Information System (INIS)

Maeda, T.

2005-01-01

Calculation of surface wave velocity is a classic problem dating back to the well-known Haskell's transfer matrix method, which contributes to solutions of elastic wave propagation, global subsurface structure evaluation by simulating observed earthquake group velocities, and on-site evaluation of subsurface structure by simulating phase velocity dispersion curves and/or H/V spectra obtained by micro-tremor observation. Recently inversion analysis on micro-tremor observation requires efficient method of generating many model candidates and also stable, accurate, and fast computation of dispersion curves and Raleigh wave trajectory. The original Haskell's transfer matrix method has been improved in terms of its divergence tendency mainly by the generalized transmission and reflection matrix method with formulation available for surface wave velocity; however, root finding algorithm has not been fully discussed except for the one by setting threshold to the absolute value of complex characteristic functions. Since surface wave number (reciprocal to the surface wave velocity multiplied by frequency) is a root of complex valued characteristic function, it is intractable to use general root finding algorithm. We will examine characteristic function in phase plane to construct two dimensional bisection algorithm with consideration on a layer to be evaluated and algorithm for tracking roots down along frequency axis. (author)

Pleasant music improves visual attention in patients with unilateral neglect after stroke.

Science.gov (United States)

Chen, Mei-Ching; Tsai, Pei-Luen; Huang, Yu-Ting; Lin, Keh-Chung

2013-01-01

To investigate whether listening to pleasant music improves visual attention to and awareness of contralesional stimuli in patients with unilateral neglect after stroke. A within-subject design was used with 19 participants with unilateral neglect following a right hemisphere stroke. Participants were tested in three conditions (pleasant music, unpleasant music and white noise) within 1 week. All musical pieces were chosen by the participants. In each condition, participants were asked to complete three sub-tests of the Behavioural Inattention Test (the Star Cancellation Test, the Line Bisection Test and the Picture Scanning test) and a visual exploration task with everyday scenes. Eye movements in the visual exploration task were recorded simultaneously. Mood and arousal induced by different auditory stimuli were assessed using visual analogue scales, heart rate and galvanic skin response. Compared with unpleasant music and white noise, participants rated their moods as more positive and arousal as higher with pleasant music, but also showed significant improvement on all tasks and eye movement data, except the Line Bisection Test. The findings suggest that pleasant music can improve visual attention in patients with unilateral neglect after stroke. Additional research using randomized controlled trials is required to validate these findings.

The Effects of Pre-Task Planning and On-line Planning on Fluency, Complexity, and Accuracy in L2 Monologic Oral Production.

Science.gov (United States)

Yuan, Fangyuan; Ellis, Rod

2003-01-01

Investigated the effects of both pre-task and on-line planning on second language (L2) oral production. Results show that pre-task planning enhances grammatical complexity while on-line planning positively influences accuracy and grammatical complexity. Pre-task planners also produced more fluent and lexically varied language than the on-line…

SOLVING OPTIMAL ASSEMBLY LINE CONFIGURATION TASK BY MULTIOBJECTIVE DECISION MAKING METHODS

Directory of Open Access Journals (Sweden)

Ján ČABALA

2017-06-01

Full Text Available This paper deals with looking for the optimal configuration of automated assembly line model placed within Department of Cybernetics and Artificial Intelligence (DCAI. In order to solve this problem, Stateflow model of each configuration was created to simulate the behaviour of particular assembly line configuration. Outputs from these models were used as inputs into the multiobjective decision making process. Multi-objective decision-making methods were subsequently used to find the optimal configuration of assembly line. Paper describes the whole process of solving this task, from building the models to choosing the best configuration. Specifically, the problem was resolved using the experts’ evaluation method for evaluating the weights of every decision-making criterion, while the ELECTRE III, TOPSIS and AGREPREF methods were used for ordering the possible solutions from the most to the least suitable alternative. Obtained results were compared and final solution of this multi-objective decisionmaking problem is chosen.

Competitive action video game players display rightward error bias during on-line video game play.

Science.gov (United States)

Roebuck, Andrew J; Dubnyk, Aurora J B; Cochran, David; Mandryk, Regan L; Howland, John G; Harms, Victoria

2017-09-12

Research in asymmetrical visuospatial attention has identified a leftward bias in the general population across a variety of measures including visual attention and line-bisection tasks. In addition, increases in rightward collisions, or bumping, during visuospatial navigation tasks have been demonstrated in real world and virtual environments. However, little research has investigated these biases beyond the laboratory. The present study uses a semi-naturalistic approach and the online video game streaming service Twitch to examine navigational errors and assaults as skilled action video game players (n = 60) compete in Counter Strike: Global Offensive. This study showed a significant rightward bias in both fatal assaults and navigational errors. Analysis using the in-game ranking system as a measure of skill failed to show a relationship between bias and skill. These results suggest that a leftward visuospatial bias may exist in skilled players during online video game play. However, the present study was unable to account for some factors such as environmental symmetry and player handedness. In conclusion, video game streaming is a promising method for behavioural research in the future, however further study is required before one can determine whether these results are an artefact of the method applied, or representative of a genuine rightward bias.

Complete NMR assignment of a bisecting hybrid-type oligosaccharide transferred by Mucor hiemalis endo-β-N-acetylglucosaminidase.

Science.gov (United States)

Yamanoi, Takashi; Oda, Yoshiki; Katsuraya, Kaname; Inazu, Toshiyuki; Yamamoto, Kenji

2016-06-02

This study describes the complete nuclear magnetic resonance (NMR) spectral assignment of a bisecting hybrid-type oligosaccharide 1, transferred by Mucor hiemalis endo-β-N-acetylglucosaminidase (Endo-M). Through (1)H- and (13)C-NMR, DQF-COSY, HSQC, HMBC, TOCSY, and NOESY experiments, we determine the structure of the glycoside linkage formed by the Endo-M transglycosylation, i.e., the connection between GlcNAc and GlcNAc in oligosaccharide 1. Copyright © 2016 Elsevier Ltd. All rights reserved.

TASK-3 Downregulation Triggers Cellular Senescence and Growth Inhibition in Breast Cancer Cell Lines

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Rafael Zúñiga

2018-03-01

Full Text Available TASK-3 potassium channels are believed to promote proliferation and survival of cancer cells, in part, by augmenting their resistance to both hypoxia and serum deprivation. While overexpression of TASK-3 is frequently observed in cancers, the understanding of its role and regulation during tumorigenesis remains incomplete. Here, we evaluated the effect of reducing the expression of TASK-3 in MDA-MB-231 and MCF-10F human mammary epithelial cell lines through small hairpin RNA (shRNA-mediated knockdown. Our results show that knocking down TASK-3 in fully transformed MDA-MB-231 cells reduces proliferation, which was accompanied by an induction of cellular senescence and cell cycle arrest, with an upregulation of cyclin-dependent kinase (CDK inhibitors p21 and p27. In non-tumorigenic MCF-10F cells, however, TASK-3 downregulation did not lead to senescence induction, although cell proliferation was impaired and an upregulation of CDK inhibitors was also evident. Our observations implicate TASK-3 as a critical factor in cell cycle progression and corroborate its potential as a therapeutic target in breast cancer treatment.

A Solution Approach to Assembly Line Balancing Problem With Task Related Constraints and an Application At An Enterprise

Directory of Open Access Journals (Sweden)

Serkan Altuntaş

2010-01-01

Full Text Available Occasionally certain tasks in an assembly line balancing problem are required to be kept together due to some specific reasons. These tasks are attained to the same work stations. Such problems are called as 'Assembly Line Balancing Problem with Task Related Constraints (ALBTRC'. Certain situations like awkward product construction, simultaneous operations or specific requirements leading to zoning and positional constraints like utilization of common resources as tools, jigs and fixtures are implemented thanks to these supplementary constraints. Additionally, materials handling and tooling costs, distances, set-up and lead times are also reduced. Literature on ALBTRC seems quite rare compared to Classical Line Balancing papers, although ALBTRC is one of the common real life balancing problems. This study aimed to develop and implement a novel line balancing method for a manufacturing concern where known methods are impractical to employ due to some specific positional constraints. 'Largest Candidate Method' known as a simple but effective tool is modified for this purpose first. Then a thorough 'method and time study' is conducted to get the necessary data to utilize that method. As a result, more efficient alternatives are generated and presented to decision maker.

Cognitive Mechanisms Underlying Directional and Non-directional Spatial-Numerical Associations across the Lifespan

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Manuel Ninaus

2017-08-01

Full Text Available There is accumulating evidence suggesting an association of numbers with physical space. However, the origin of such spatial-numerical associations (SNAs is still debated. In the present study we investigated the development of two SNAs in a cross-sectional study involving children, young and middle-aged adults as well as the elderly: (1 the SNARC (spatial-numerical association of response codes effect, reflecting a directional SNA; and (2 the numerical bisection bias in a line bisection task with numerical flankers. Results revealed a consistent SNARC effect in all age groups that continuously increased with age. In contrast, a numerical bisection bias was only observed for children and elderly participants, implying an U-shaped distribution of this bias across age groups. Additionally, individual SNARC effects and numerical bisection biases did not correlate significantly. We argue that the SNARC effect seems to be influenced by longer-lasting experiences of cultural constraints such as reading and writing direction and may thus reflect embodied representations. Contrarily, the numerical bisection bias may originate from insufficient inhibition of the semantic influence of irrelevant numerical flankers, which should be more pronounced in children and elderly people due to development and decline of cognitive control, respectively. As there is an ongoing debate on the origins of SNAs in general and the SNARC effect in particular, the present results are discussed in light of these differing accounts in an integrative approach. However, taken together, the present pattern of results suggests that different cognitive mechanisms underlie the SNARC effect and the numerical bisection bias.

A tangent subsolar merging line

International Nuclear Information System (INIS)

Crooker, N.U.; Siscoe, G.L.; Toffoletto, F.R.

1990-01-01

The authors describe a global magnetospheric model with a single subsolar merging line whose position is determined neither locally by the relative orientations and strengths of the merging fields nor globally by the orientation of a separator line--the governing parameters of most previous models--but by the condition of tangential contact between the external field and the magnetopause. As in previous models, the tilt of the merging line varies with IMF orientation, but here it also depends upon the ratio of Earth's magnetic flux that leaks out of the magnetopause to IMF flux that penetrates in. In the limiting case treated by Alekseyev and Belen'kaya, with no leakage of Earth's field and total IMF penetration, the merging line forms a great circle around a spherical magnetosphere where undeviated IMF lines lie tangent to its surface. This tangent merging line lies perpendicular to the IMF. They extend their work to the case of finite leakage and partial penetration, which distort the IMF into a draped pattern, thus changing the locus of tangency to the sphere. In the special case where the penetrating IMF flux is balanced by an equal amount of Earth flux leakage, the tangent merging line bisects the angle between the IMF and Earth's northward subsolar field. This result is identical to the local merging line model result for merging fields with equal magnitude. Here a global flux balance condition replaces the local equal magnitude condition

Effects of listening to pleasant music on chronic unilateral neglect: a single-subject study.

Science.gov (United States)

Tsai, Pei-Luen; Chen, Mei-Ching; Huang, Yu-Ting; Lin, Keh-Chung

2013-01-01

Recent studies suggest that the positive emotion induced by pleasant music may improve cognitive functions. We used the single-subject design to study whether listening to preferred music may reduce unilateral neglect in two participants with post-stroke neglect. These participants were instructed to listen to their preferred music every day for 5 weeks, followed by 2 weeks of follow-up assessment. Outcome measures involved the Star Cancellation Test, the Line Bisection Test, and the visual exploration task. A combination of visual analysis and the two-standard-deviation band method was used for data analysis. Both participants showed significant intervention-related improvements on all outcome measures except the Line Bisection Test, on which one participant showed no improvement. The therapeutic effects were maintained during the follow-up phase. The findings suggest that positive emotion, evoked by preferred music, may be used to ameliorate unilateral neglect. Further research using controlled trials is warranted to validate the findings.

Efficacy of home-based visuomotor feedback training in stroke patients with chronic hemispatial neglect.

Science.gov (United States)

Rossit, Stéphanie; Benwell, Christopher S Y; Szymanek, Larissa; Learmonth, Gemma; McKernan-Ward, Laura; Corrigan, Elaine; Muir, Keith; Reeves, Ian; Duncan, George; Birschel, Philip; Roberts, Margaret; Livingstone, Katrina; Jackson, Hazel; Castle, Pauline; Harvey, Monika

2017-01-24

Hemispatial neglect is a severe cognitive condition frequently observed after a stroke, associated with unawareness of one side of space, disability and poor long-term outcome. Visuomotor feedback training (VFT) is a neglect rehabilitation technique that involves a simple, inexpensive and feasible training of grasping-to-lift rods at the centre. We compared the immediate and long-term effects of VFT vs. a control training when delivered in a home-based setting. Twenty participants were randomly allocated to an intervention (who received VFT) or a control group (n = 10 each). Training was delivered for two sessions by an experimenter and then patients self-administered it for 10 sessions over two weeks. Outcome measures included the Behavioural Inattention Test (BIT), line bisection, Balloons Test, Landmark task, room description task, subjective straight-ahead pointing task and the Stroke Impact Scale. The measures were obtained before, immediately after the training sessions and after four-months post-training. Significantly greater short and long-term improvements were obtained after VFT when compared to control training in line bisection, BIT and spatial bias in cancellation. VFT also produced improvements on activities of daily living. We conclude that VFT is a feasible, effective, home-based rehabilitation method for neglect patients that warrants further investigation with well-designed randomised controlled trials on a large sample of patients.

Mathematics anxiety reduces default mode network deactivation in response to numerical tasks

Directory of Open Access Journals (Sweden)

Belinda ePletzer

2015-04-01

Full Text Available Mathematics anxiety is negatively related to mathematics performance, thereby threatening the professional success. Preoccupation with the emotional content of the stimuli may consume working memory resources, which may be reflected in decreased deactivation of areas associated with the default mode network (DMN activated during self-referential and emotional processing. The common problem is that math anxiety is usually associated with poor math performance, so that any group differences are difficult to interpret.Here we compared the BOLD-response of 18 participants with high (HMAs and 18 participants with low mathematics anxiety (LMAs matched for their mathematical performance to two numerical tasks (number comparison, number bisection. During both tasks, we found stronger deactivation within the DMN in LMAs compared to HMAs, while BOLD-response in task-related activation areas did not differ between HMAs and LMAs. The difference in DMN deactivation between the HMA and LMA group was more pronounced in stimuli with additional requirement on inhibitory functions, but did not differ between number magnitude processing and arithmetic fact retrieval.

Mathematics anxiety reduces default mode network deactivation in response to numerical tasks.

Science.gov (United States)

Pletzer, Belinda; Kronbichler, Martin; Nuerk, Hans-Christoph; Kerschbaum, Hubert H

2015-01-01

Mathematics anxiety is negatively related to mathematics performance, thereby threatening the professional success. Preoccupation with the emotional content of the stimuli may consume working memory resources, which may be reflected in decreased deactivation of areas associated with the default mode network (DMN) activated during self-referential and emotional processing. The common problem is that math anxiety is usually associated with poor math performance, so that any group differences are difficult to interpret. Here we compared the BOLD-response of 18 participants with high (HMAs) and 18 participants with low mathematics anxiety (LMAs) matched for their mathematical performance to two numerical tasks (number comparison, number bisection). During both tasks, we found stronger deactivation within the DMN in LMAs compared to HMAs, while BOLD-response in task-related activation areas did not differ between HMAs and LMAs. The difference in DMN deactivation between the HMA and LMA group was more pronounced in stimuli with additional requirement on inhibitory functions, but did not differ between number magnitude processing and arithmetic fact retrieval.

The task-to-task communication between computers

International Nuclear Information System (INIS)

Lin Shuzi; Zhang Bingyun; Zhao Weiren

1992-01-01

The task-to-task communication is used in the Institute of High Energy Physics. The BES (Beijing Spectrometer) uses the communication mode to take some of the BEPC (Beijing Electron Positron Collider) running parameters needed by BES experiments in a periodic time. The authors describe the principle of transparent task-to-task communication and how to use it in BES on-line data acquisition system

The influence of tactile cognitive maps on auditory space perception in sighted persons.

Directory of Open Access Journals (Sweden)

Alessia Tonelli

2016-11-01

Full Text Available We have recently shown that vision is important to improve spatial auditory cognition. In this study we investigate whether touch is as effective as vision to create a cognitive map of a soundscape. In particular we tested whether the creation of a mental representation of a room, obtained through tactile exploration of a 3D model, can influence the perception of a complex auditory task in sighted people. We tested two groups of blindfolded sighted people – one experimental and one control group – in an auditory space bisection task. In the first group the bisection task was performed three times: specifically, the participants explored with their hands the 3D tactile model of the room and were led along the perimeter of the room between the first and the second execution of the space bisection. Then, they were allowed to remove the blindfold for a few minutes and look at the room between the second and third execution of the space bisection. Instead, the control group repeated for two consecutive times the space bisection task without performing any environmental exploration in between. Considering the first execution as a baseline, we found an improvement in the precision after the tactile exploration of the 3D model. Interestingly, no additional gain was obtained when room observation followed the tactile exploration, suggesting that no additional gain was obtained by vision cues after spatial tactile cues were internalized. No improvement was found between the first and the second execution of the space bisection without environmental exploration in the control group, suggesting that the improvement was not due to task learning. Our results show that tactile information modulates the precision of an ongoing space auditory task as well as visual information. This suggests that cognitive maps elicited by touch may participate in cross-modal calibration and supra-modal representations of space that increase implicit knowledge about sound

Right up There: Hemispatial and Hand Asymmetries of Altitudinal Pseudoneglect

Science.gov (United States)

Suavansri, Ketchai; Falchook, Adam D.; Williamson, John B.; Heilman, Kenneth M.

2012-01-01

Background: Pseudoneglect is a normal left sided spatial bias observed with attempted bisections of horizontal lines and a normal upward bias observed with attempted bisections of vertical lines. Horizontal pseudoneglect has been attributed to right hemispheric dominance for the allocation of attention. The goal of this study was to test the…

Tourism Impacts of Three Mile Island and Other Adverse Events: Implications for Lincoln County and Other Rural Counties Bisected by Radioactive Wastes Intended for Yucca Mountain.

Science.gov (United States)

Himmelberger, Jeffery J.; And Others

1995-01-01

Summarizes key research implications of Three Mile Island and other major hazard events as related to tourism. Examines how the proposed Yucca Mountain nuclear waste repository system will impact tourism in southern Nevada and other visitor-oriented rural counties bisected by planned waste transportation corridors. (AIM)

Task-failure-driven rebalancing of disassembly lines

OpenAIRE

Altekin, Fatma Tevhide; Akkan, Can

2011-01-01

Many reverse-logistics systems that collect and reprocess end-of-life products require a disassembly stage. The nature of variability in incoming products, and damages, which are more likely to occur during disassembly than assembly, create a significant uncertainty in disassembly tasks, namely, possibility of failed tasks. Such failures may lead to some successor tasks being infeasible, which changes work contents of downstream stations. To improve the profitability of such a disassembly lin...

Spectral bisection algorithm for solving Schrodinger equation using upper and lower solutions

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Qutaibeh Deeb Katatbeh

2007-10-01

Full Text Available This paper establishes a new criteria for obtaining a sequence of upper and lower bounds for the ground state eigenvalue of Schr"odinger equation $ -Deltapsi(r+V(rpsi(r=Epsi(r$ in $N$ spatial dimensions. Based on this proposed criteria, we prove a new comparison theorem in quantum mechanics for the ground state eigenfunctions of Schrodinger equation. We determine also lower and upper solutions for the exact wave function of the ground state eigenfunctions using the computed upper and lower bounds for the eigenvalues obtained by variational methods. In other words, by using this criteria, we prove that the substitution of the lower(upper bound of the eigenvalue in Schrodinger equation leads to an upper(lower solution. Finally, two proposed iteration approaches lead to an exact convergent sequence of solutions. The first one uses Raielgh-Ritz theorem. Meanwhile, the second approach uses a new numerical spectral bisection technique. We apply our results for a wide class of potentials in quantum mechanics such as sum of power-law potentials in quantum mechanics.

The U-line line balancing problem

NARCIS (Netherlands)

Miltenburg, G.J.; Wijngaard, J.

1994-01-01

The traditional line balancing (LB) problem considers a production line in which stations are arranged consecutively in a line. A balance is determined by grouping tasks into stations while moving forward (or backward) through a precedence network. Recently many production lines are being arranged

Influence of spatial perception abilities on reading in school-age children

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Arnaud Saj

2015-12-01

Full Text Available Spatial perception abilities enable individuals to explore a visual field, to detect spatial position and to infer relationships between visual stimuli. Written words and text are conceptualized spatially along a horizontal mental line, but little is known about the way children develop these representations. The exact relationship between visuo-spatial perception and academic achievement has never been directly assessed. Therefore, our aim was to study the developmental trajectory of space perception abilities by assessing perceptual, attentional and memory components, the relationship between these abilities and reading achievement in school-age children. Forty-nine children aged between 6.5 and 11 years old were divided into four age groups and were assessed with visual bisection, visual search and visual memory location tasks. The results showed that the groups of older children, from the age of nine, improved significantly on the bisection and visual search tasks with respect to all visual fields, while the groups of younger children showed more errors in the left visual field (LVF. Performances on these tasks were correlated with reading level and age. Older children with a low reading score showed a LVF bias, similar to the youngest children. These results demonstrate how abnormal space perception might distort space representation and in turn affect reading and learning processes.

Listening to white noise counteracts visual and haptic pseudoneglect.

Science.gov (United States)

Cattaneo, Zaira; Lega, Carlotta; Vecchi, Tomaso; Vallar, Giuseppe

2012-01-01

Neurologically intact individuals usually show a leftward bias in line bisection, a tendency known as "pseudoneglect", likely reflecting a right-hemisphere dominance in controlling the allocation of spatial attention. Studies in brain-damaged patients with left visuospatial neglect have reported that auditory stimulation may reduce the deficit, both in a spatially dependent and in a spatially independent way. Here we show for the first time that the concurrent binaural presentation of auditory white noise affects healthy individuals' performance in both visual and haptic bisection, reducing their leftward error. We suggest that this effect depends on the noise boosting alertness and restoring the hemispheric activation balance. Our data clearly show that task-irrelevant auditory noise crossmodally affects the allocation of spatial resources in both the haptic and the visual space; future research may clarify whether these effects are specific for the type of auditory stimulation.

Early Visual Deprivation Severely Compromises the Auditory Sense of Space in Congenitally Blind Children

Science.gov (United States)

Vercillo, Tiziana; Burr, David; Gori, Monica

2016-01-01

A recent study has shown that congenitally blind adults, who have never had visual experience, are impaired on an auditory spatial bisection task (Gori, Sandini, Martinoli, & Burr, 2014). In this study we investigated how thresholds for auditory spatial bisection and auditory discrimination develop with age in sighted and congenitally blind…

Off-line mapping of multi-rate dependent task sets to many-core platforms

DEFF Research Database (Denmark)

Puffitsch, Wolfgang; Noulard, Eric; Pagetti, Claire

2015-01-01

This paper presents an approach to execute safety-critical applications on multi- and many-core processors in a predictable manner. We investigate three concrete platforms: the Intel Single-chip Cloud Computer, the Texas Instruments TMS320C6678 and the Tilera TILEmpower-Gx36. We define an execution...... model to safely execute dependent periodic task sets on these platforms. The four rules of the execution model entail that an off-line mapping of the application to the platform must be computed. The paper details our approach to automatically compute a valid mapping. Furthermore, we evaluate our...

Time estimation in mild Alzheimer's disease patients

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Nichelli Paolo

2009-07-01

Full Text Available Abstract Background Time information processing relies on memory, which greatly supports the operations of hypothetical internal timekeepers. Scalar Expectancy Theory (SET postulates the existence of a memory component that is functionally separated from an internal clock and other processing stages. SET has devised several experimental procedures to map these cognitive stages onto cerebral regions and neurotransmitter systems. One of these, the time bisection procedure, has provided support for a dissociation between the clock stage, controlled by dopaminergic systems, and the memory stage, mainly supported by cholinergic neuronal networks. This study aimed at linking the specific memory processes predicted by SET to brain mechanisms, by submitting time bisection tasks to patients with probable Alzheimer's disease (AD, that are known to present substantial degeneration of the fronto-temporal regions underpinning memory. Methods Twelve mild AD patients were required to make temporal judgments about intervals either ranging from 100 to 600 ms (short time bisection task or from 1000 to 3000 ms (long time bisection task. Their performance was compared with that of a group of aged-matched control participants and a group of young control subjects. Results Long time bisection scores of AD patients were not significantly different from those of the two control groups. In contrast, AD patients showed increased variability (as indexed by increased WR values in timing millisecond durations and a generalized inconsistency of responses over the same interval in both the short and long bisection tasks. A similar, though milder, decreased millisecond interval sensitivity was found for elderly subjects. Conclusion The present results, that are consistent with those of previous timing studies in AD, are interpreted within the SET framework as not selectively dependent on working or reference memory disruptions but as possibly due to distortions in different

Memory for Spatial Locations in a Patient with Near Space Neglect and Optic Ataxia: Involvement of the Occipitotemporal Stream

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Sergio Chieffi

2017-05-01

Full Text Available Previous studies suggested that the occipitoparietal stream orients attention toward the near/lower space and is involved in immediate reaching, whereas the occipitotemporal stream orients attention toward the far/upper space and is involved in delayed reaching. In the present study, we investigated the role of the occipitotemporal stream in attention orienting and delayed reaching in a patient (GP with bilateral damage to the occipitoparietal areas and optic ataxia. GP and healthy controls took part in three experiments. In the experiment 1, the participants bisected lines oriented along radial, vertical, and horizontal axes. GP bisected radial lines farther, and vertical lines more above, than the controls, consistent with an attentional bias toward the far/upper space and near/lower space neglect. The experiment 2 consisted of two tasks: (1 an immediate reaching task, in which GP reached target locations under visual control and (2 a delayed visual reaching task, in which GP and controls were asked to reach remembered target locations visually presented. We measured constant and variable distance and direction errors. In immediate reaching task, GP accurately reached target locations. In delayed reaching task, GP overshot remembered target locations, whereas the controls undershot them. Furthermore, variable errors were greater in GP than in the controls. In the experiment 3, GP and controls performed a delayed proprioceptive reaching task. Constant reaching errors did not differ between GP and the controls. However, variable direction errors were greater in GP than in the controls. We suggest that the occipitoparietal damage, and the relatively intact occipitotemporal region, produced in GP an attentional orienting bias toward the far/upper space (experiment 1. In turns, the attentional bias selectively shifted toward the far space remembered visual (experiment 2, but not proprioceptive (experiment 3, target locations. As a whole, these

An exploratory fNIRS study with immersive virtual reality: a new method for technical implementation.

Science.gov (United States)

Seraglia, Bruno; Gamberini, Luciano; Priftis, Konstantinos; Scatturin, Pietro; Martinelli, Massimiliano; Cutini, Simone

2011-01-01

For over two decades Virtual Reality (VR) has been used as a useful tool in several fields, from medical and psychological treatments, to industrial and military applications. Only in recent years researchers have begun to study the neural correlates that subtend VR experiences. Even if the functional Magnetic Resonance Imaging (fMRI) is the most common and used technique, it suffers several limitations and problems. Here we present a methodology that involves the use of a new and growing brain imaging technique, functional Near-infrared Spectroscopy (fNIRS), while participants experience immersive VR. In order to allow a proper fNIRS probe application, a custom-made VR helmet was created. To test the adapted helmet, a virtual version of the line bisection task was used. Participants could bisect the lines in a virtual peripersonal or extrapersonal space, through the manipulation of a Nintendo Wiimote ® controller in order for the participants to move a virtual laser pointer. Although no neural correlates of the dissociation between peripersonal and extrapersonal space were found, a significant hemodynamic activity with respect to the baseline was present in the right parietal and occipital areas. Both advantages and disadvantages of the presented methodology are discussed.

The Task Is Not Enough: Processing Approaches to Task-Based Performance

Science.gov (United States)

Skehan, Peter; Xiaoyue, Bei; Qian, Li; Wang, Zhan

2012-01-01

This article reports on three research studies, all of which concern second language task performance. The first focuses on planning, and compares on-line and strategic planning as well as task repetition. The second study examines the role of familiarity on task performance, and compares this with conventional strategic planning. The third study…

A tetraantennary glycan with bisecting N-acetylglucosamine and the Sda antigen is the predominant N-glycan on bovine pregnancy-associated glycoproteins

DEFF Research Database (Denmark)

Klisch, Karl; Jeanrond, Evelyne; Pang, Poh-Choo

2008-01-01

assisted laser desorption ionisation-mass spectrometry (MALDI-MS) analysis and linkage analysis, we show that by far, the most abundant N-glycan of PAGs in midpregnancy is a tetraantennary core-fucosylated structure with a bisecting N-acetylglucosamine (GlcNAc). All four antennae consist of the Sd......(a)-antigen (NeuAcalpha2-3[GalNAcbeta1-4]Galbeta1-4GlcNAc-). Immunohistochemistry with the mono- clonal antibody CT1, which recognizes the Sd(a)-antigen, shows that BNC granules contain the Sd(a)-antigen from gestation day (gd) 32 until a few days before parturition. Lectin histochemistry with Maackia amurensis...

Putative porcine embryonic stem cell lines derived from aggregated four-celled cloned embryos produced by oocyte bisection cloning.

Science.gov (United States)

Siriboon, Chawalit; Lin, Yu-Hsuan; Kere, Michel; Chen, Chun-Da; Chen, Lih-Ren; Chen, Chien-Hong; Tu, Ching-Fu; Lo, Neng-Wen; Ju, Jyh-Cherng

2015-01-01

We attempted to isolate ES cell lines using inner cell masses from high-quality cloned porcine blastocysts. After being seeded onto feeders, embryos had better (P cloned embryos (62.8, 42.6 and 12.8% vs. 76.2, 55.2 and 26.2%, respectively) compared to the non-aggregated group (41.6, 23.4 and 3.9%). Effects of feeder types (STO vs. MEF) and serum sources (FBS vs. KSR) on extraction of cloned embryo-derived porcine ES cells were examined. More (17.1%) ntES cell lines over Passage 3 were generated in the MEF/KSR group. However, ntES cells cultured in KSR-supplemented medium had a low proliferation rate with defective morphology, and eventually underwent differentiation or apoptosis subsequently. Approximately 26.1, 22.7 and 35.7% of primary colonies were formed after plating embryos in DMEM, DMEM/F12 and α-MEM media, respectively. Survival rates of ntES cells cultured in α-MEM, DMEM and DMEM/F12 were 16.7, 4.3 and 6.8%, respectively (P > 0.05). We further examined the beneficial effect of TSA treatment of 3× aggregated cloned embryos on establishment of ntES cell lines. Primary colony numbers and survival rates of ntES cells beyond passage 3 were higher (P cells, remaining undifferentiated over 25 passages, had alkaline phosphatase activity and expressed ES specific markers Oct4, Nanog, Sox2, and Rex01. Moreover, these ntES cells successfully differentiated into embryoid bodies (EBs) that expressed specific genes of all three germ layers after being cultured in LIF-free medium. In conclusion, we have successfully derived putative porcine ntES cells with high efficiency from quality cloned embryos produced by embryo aggregation, and optimized the ES cell culture system suitable for establishing and maintaining ntES cell lines in undifferentiated state.

Sex differences on the judgment of line orientation task: a function of landmark presence and hormonal status.

Science.gov (United States)

Goyette, Sharon Ramos; McCoy, John G; Kennedy, Ashley; Sullivan, Meghan

2012-02-28

It has been well-established that men outperform women on some spatial tasks. The tools commonly used to demonstrate this difference (e.g. The Mental Rotations Task) typically involve problems and solutions that are presented in a context devoid of referents. The study presented here assessed whether the addition of referents (or "landmarks") would attenuate the well-established sex difference on the judgment of line orientation task (JLOT). Three versions of the JLOT were presented in a within design. The first iteration contained the original JLOT (JLOT 1). JLOT 2 contained three "landmarks" or referents and JLOT 3 contained only one landmark. The sex difference on JLOT 1 was completely negated by the addition of three landmarks on JLOT 2 or the addition of one landmark on JLOT3. In addition, salivary testosterone was measured. In men, gains in performance on the JLOT due to the addition of landmarks were positively correlated with testosterone levels. This suggests that men with the highest testosterone levels benefited the most from the addition of landmarks. These data help to highlight different strategies used by men and women to solve spatial tasks. Copyright © 2011 Elsevier Inc. All rights reserved.

Communication Characterization and Optimization of Applications Using Topology-Aware Task Mapping on Large Supercomputers

Energy Technology Data Exchange (ETDEWEB)

Sreepathi, Sarat [ORNL; D' Azevedo, Eduardo [ORNL; Philip, Bobby [ORNL; Worley, Patrick H [ORNL

2016-01-01

On large supercomputers, the job scheduling systems may assign a non-contiguous node allocation for user applications depending on available resources. With parallel applications using MPI (Message Passing Interface), the default process ordering does not take into account the actual physical node layout available to the application. This contributes to non-locality in terms of physical network topology and impacts communication performance of the application. In order to mitigate such performance penalties, this work describes techniques to identify suitable task mapping that takes the layout of the allocated nodes as well as the application's communication behavior into account. During the first phase of this research, we instrumented and collected performance data to characterize communication behavior of critical US DOE (United States - Department of Energy) applications using an augmented version of the mpiP tool. Subsequently, we developed several reordering methods (spectral bisection, neighbor join tree etc.) to combine node layout and application communication data for optimized task placement. We developed a tool called mpiAproxy to facilitate detailed evaluation of the various reordering algorithms without requiring full application executions. This work presents a comprehensive performance evaluation (14,000 experiments) of the various task mapping techniques in lowering communication costs on Titan, the leadership class supercomputer at Oak Ridge National Laboratory.

An Exploratory fNIRS Study with Immersive Virtual Reality: A New Method for Technical Implementation

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Bruno eSeraglia

2011-12-01

Full Text Available For over two decades Virtual Reality has been used as a useful tool in several fields, from medical and psychological treatments, to industrial and military applications. Only in recent years researchers have begun to study the neural correlates that subtend virtual reality experiences. Even if the fMRI brain image technique is the most common and used technique, it suffers several limitations and problems. Here we present a methodology that involves the use of a new and growing brain imaging technique, fNIRS functional Near-infrared Spectroscopy, while participants experience immersive virtual reality. In order to allow a proper fNIRS probe application, a custom-made virtual reality helmet was created. To test the adapted helmet, a virtual version of the line bisection task was used. Participants could bisect the lines in a virtual peripersonal or extrapersonal space, through the manipulation of a Wiimote controller in order for the participants to move a virtual laser pointer. Although no neural correlates of the dissociation between peripersonal and extrapersonal space were found, a significant hemodynamic activity with respect to the baseline was present in the right parietal and occipital areas. Both advantages and disadvantages of the presented methodology are discussed.

Type of Material in the Pipes Overhead Power Lines Impact on the Distribution on the Size of the Overhang and the Tension

Science.gov (United States)

Pawlak, Urszula; Pawlak, Marcin

2017-10-01

The article presents the material type from which the conductors of the overhead power lines are produced influences on the size of the overhang and the tension. The aim of the calculations was to present the benefits of the mechanics of the cable resulting from the type of cable used. The analysis was performed for two types of cables: aluminium with steel core and aluminium with composite core, twice span power line section. 10 different conductor-to-strand coil, wind, icing, and temperature variations were included in the calculations. The string description was made by means of a chain curve, while the horizontal component H of the tension force was determined using the bisection method. The loads were collected in accordance with applicable Eurocode.

Time flies with music whatever its emotional valence.

Science.gov (United States)

Droit-Volet, Sylvie; Bigand, Emmanuel; Ramos, Danilo; Bueno, José Lino Oliveira

2010-10-01

The present study used a temporal bisection task to investigate whether music affects time estimation differently from a matched auditory neutral stimulus, and whether the emotional valence of the musical stimuli (i.e., sad vs. happy music) modulates this effect. The results showed that, compared to sine wave control music, music presented in a major (happy) or a minor (sad) key shifted the bisection function toward the right, thus increasing the bisection point value (point of subjective equality). This indicates that the duration of a melody is judged shorter than that of a non-melodic control stimulus, thus confirming that "time flies" when we listen to music. Nevertheless, sensitivity to time was similar for all the auditory stimuli. Furthermore, the temporal bisection functions did not differ as a function of musical mode. Copyright © 2010 Elsevier B.V. All rights reserved.

Context effects in a temporal discrimination task" further tests of the Scalar Expectancy Theory and Learning-to-Time models.

Science.gov (United States)

Arantes, Joana; Machado, Armando

2008-07-01

Pigeons were trained on two temporal bisection tasks, which alternated every two sessions. In the first task, they learned to choose a red key after a 1-s signal and a green key after a 4-s signal; in the second task, they learned to choose a blue key after a 4-s signal and a yellow key after a 16-s signal. Then the pigeons were exposed to a series of test trials in order to contrast two timing models, Learning-to-Time (LeT) and Scalar Expectancy Theory (SET). The models made substantially different predictions particularly for the test trials in which the sample duration ranged from 1 s to 16 s and the choice keys were Green and Blue, the keys associated with the same 4-s samples: LeT predicted that preference for Green should increase with sample duration, a context effect, but SET predicted that preference for Green should not vary with sample duration. The results were consistent with LeT. The present study adds to the literature the finding that the context effect occurs even when the two basic discriminations are never combined in the same session.

Engineering task plan for steam line ramp calculations

International Nuclear Information System (INIS)

DeSantis, G.N.; Freeman, R.D.

1994-01-01

The purpose of this document is to provide an approved work plan to perform calculations that verify the load limits of a proposed ramp over a steam line at the back side (East side) of SY Farm in support of work package 2W-94-00812/K. The objective of this supporting document is to provide Operations with a set of checked calculations that verify the ramp over the steam line at SY Farm will support a fully loaded concrete mixer truck without affecting the steam line. The calculations will be performed by an engineers from Facility Systems and independently checked and reviewed by another engineer. The calculations may then be added to the work package. If Operations decides to make any configuration changes to the steam line or surrounding area, Operations shall have these changes documented by an Engineering Change Notice (ECN). This ECN can be done by Facility Systems or any other engineering organization at the direction of Operations

Time, number and length: similarities and differences in discrimination in adults and children.

Science.gov (United States)

Droit-Volet, Sylvie; Clément, Angélique; Fayol, Michel

2008-01-01

The aim of this study was to focus on similarities in the discrimination of three different quantities--time, number, and line length--using a bisection task involving children aged 5 and 8 years and adults, when number and length were presented nonsequentially (Experiment 1) and sequentially (Experiment 2). In the nonsequential condition, for all age groups, although to a greater extent in the younger children, the psychophysical functions were flatter, and the Weber ratio higher for time than for number and length. Number and length yielded similar psychophysical functions. Thus, sensitivity to time was lower than that to the other quantities, whether continuous or not. However, when number and length were presented sequentially (Experiment 2), the differences in discrimination performance between time, number, and length disappeared. Furthermore, the Weber ratio values as well as the bisection points for all quantities presented sequentially appeared to be close to that found for duration in the nonsequential condition. The results are discussed within the framework of recent theories suggesting a common mechanism for all analogical quantities.

Different methods to define utility functions yield similar results but engage different neural processes

Directory of Open Access Journals (Sweden)

Marcus Heldmann

2009-10-01

Full Text Available Although the concept of utility is fundamental to many economic theories, up to now a generally accepted method determining a subject’s utility function is not available. We investigated two methods that are used in economic sciences for describing utility functions by using response-locked event-related potentials in order to assess their neural underpinnings. For defining the certainty equivalent (CE, we used a lottery game with probabilities to win p=0.5, for identifying the subjects’ utility functions directly a standard bisection task was applied. Although the lottery tasks’ payoffs were only hypothetical, a pronounced negativity was observed resembling the error related negativity (ERN previously described in action monitoring research, but this occurred only for choices far away from the indifference point between money and lottery. By contrast, the bisection task failed to evoke an ERN irrespective of the responses’ correctness. Based on these findings we are reasoning that only decisions made in the lottery task achieved a level of subjective relevance that activates cognitive-emotional monitoring. In terms of economic sciences, our findings support the view that the bisection method is unaffected by any kind of probability valuation or other parameters related to risk and in combination with the lottery task can, therefore, be used to differentiate between payoff and probability valuation.

Time Perception in Children Treated for a Cerebellar Medulloblastoma

Science.gov (United States)

Droit-Volet, Sylvie; Zelanti, Pierre S.; Dellatolas, Georges; Kieffer, Virginie; El Massioui, Nicole; Brown, Bruce L.; Doyere, Valerie; Provasi, Joelle; Grill, Jacques

2013-01-01

The aim of the present study was to investigate temporal abilities in children treated by surgery for a malignant tumor in the cerebellum. Children with a diagnosed medulloblastoma and age-paired control children were given a temporal discrimination task (bisection task) and a temporal reproduction task with two duration ranges, one shorter than 1…

Screening tests are not enough to detect hemineglect Testes de triagem não são suficientes para diagnosticar heminegligência

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Manuel Alvim Leite Lopes

2007-12-01

Full Text Available OBJECTIVE: To verify the sensitivity of the conventional subtests of the Behavioral Inattention Test (BIT in the diagnosis of hemineglect after stroke. METHOD: One hundred and two patients with cerebral infarct or hemorrhage were prospectively evaluated. In 22, hemineglect was diagnosed using standard BIT criteria. The frequency of hemineglect using 6 commonly used screening subtests of this battery was assessed. RESULTS: Hemineglect would not be recognized in 10 patients if they were only screened using the line crossing test; this would be the case in 2 patients with the letter cancellation test; and in 4 patient with the line bisection test. Three patients would not be diagnosed even if both line crossing and line bisection tests were used. CONCLUSION: Hemineglect may not be recognized with single screening tests commonly used. The use of a standard battery is recommended to improve diagnostic sensitivity in individuals with various subtypes of hemineglect.OBJETIVO: Verificar a sensibilidade dos subtestes convencionais da Behavioral Inattention Test (BIT no diagnóstico da heminegligência após o acidente vascular cerebral (AVC. MÉTODO: Foram avaliados prospectivamente 102 pacientes com AVC. Em 22 casos heminegligência foi diagnosticada através do BIT. A freqüência de diagnóstico correto utilizando os 6 subtestes específicos desta bateria foi analisada. RESULTADOS: 10 pacientes não seriam diagnosticados como heminegligentes se fossem avaliados apenas com o " line crossing" , 2 se o teste de triagem escolhido fosse o " letter cancellation" , e 4 se utilizássemos apenas o " line bisection" . Além disso, 3 pacientes não teriam recebido o diagnóstico correto mesmo utilizando dois testes usuais de triagem - " line crossing" e " line bisection" . CONCLUSÃO: O uso de testes isolados de triagem pode falhar em diagnosticar heminegligência após o AVC. O uso de uma bateria formal de avaliação é necessário para identificar indiv

Tourism impacts of Three Mile Island and other adverse events: implications for Lincoln County and other rural counties bisected by radioactive wastes intended for Yucca Mountain

International Nuclear Information System (INIS)

Himmelberger, J.J.; Baughman, M.; Ogneva-Himmelberger, Y.A.

1995-01-01

Whether the proposed Yucca Mountain nuclear waste repository system will adversely impact tourism in southern Nevada is an open question of particular importance to visitor-oriented rural counties bisected by planned waste transportation corridors (highway or rail). As part of one such county's repository impact assessment program, tourism implications of Three Mile Island (TMI) and other major hazard events have been revisited to inform ongoing county-wide socioeconomic assessments and contingency planning efforts. This paper summarizes key research implications of such research as applied to Lincoln County, Nevada. Implications for other rural counties are discussed in light of the research findings

Backwards Fading to Speed Task Learning

Science.gov (United States)

2013-09-01

shift a person away from heavy reliance on the scaffolding provided by worked examples and towards a scaffold- free condition of problem solving...rope (trailing free end). Bring it around the waist to the front and make two overhand twists/loops on the other strand of rope, thus creating a...left or right) up under the loop around the waist, bisecting the back pocket flap on the trousers. 7. Pull up on both ropes (while squatting

Tourism impacts of Three Mile Island and other adverse events: Implications for Lincoln County and other rural counties bisected by radioactive wastes intended for Yucca Mountain

Energy Technology Data Exchange (ETDEWEB)

Himmelberger, J.J.; Ogneva-Himmelberger, Y.A. [Clark Univ., Worcester, MA (United States); Baughman, M. [Interech Services Corporation, Carson City, NV (United States)

1995-11-01

Whether the proposed Yucca Mountain nuclear waste repository system will adversely impact tourism in southern Nevada is an open question of particular importance to visitor-oriented rural counties bisected by planned waste transportation corridors (highway or rail). As part of one such county`s repository impact assessment program, tourism implications of Three Mile Island (TMI) and other major hazard events have been revisited to inform ongoing county-wide socioeconomic assessments and contingency planning efforts. This paper summarizes key research implications of such research as applied to Lincoln County, Nevada. Implications for other rural counties are discussed in light of the research findings. 29 refs., 3 figs., 1 tab.

The log-linear response function of the bounded number-line task is unrelated to the psychological representation of quantity.

Science.gov (United States)

Cohen, Dale J; Quinlan, Philip T

2018-02-01

The bounded number-line task has been used extensively to assess the numerical competence of both children and adults. One consistent finding has been that young children display a logarithmic response function, whereas older children and adults display a more linear response function. Traditionally, these log-linear functions have been interpreted as providing a transparent window onto the nature of the participants' psychological representations of quantity (termed here a direct response strategy). Here we show that the direct response strategy produces the log-linear response function regardless of whether the psychological representation of quantity is compressive or expansive. Simply put, the log-linear response function results from task constraints rather than from the psychological representation of quantities. We also demonstrate that a proportion/subtraction response strategy produces response patterns that almost perfectly correlate with the psychological representation of quantity. We therefore urge researchers not to interpret the log-linear response pattern in terms of numerical representation.

Egocentric and allocentric alignment tasks are affected by otolith input.

Science.gov (United States)

Tarnutzer, Alexander A; Bockisch, Christopher J; Olasagasti, Itsaso; Straumann, Dominik

2012-06-01

Gravicentric visual alignments become less precise when the head is roll-tilted relative to gravity, which is most likely due to decreasing otolith sensitivity. To align a luminous line with the perceived gravity vector (gravicentric task) or the perceived body-longitudinal axis (egocentric task), the roll orientation of the line on the retina and the torsional position of the eyes relative to the head must be integrated to obtain the line orientation relative to the head. Whether otolith input contributes to egocentric tasks and whether the modulation of variability is restricted to vision-dependent paradigms is unknown. In nine subjects we compared precision and accuracy of gravicentric and egocentric alignments in various roll positions (upright, 45°, and 75° right-ear down) using a luminous line (visual paradigm) in darkness. Trial-to-trial variability doubled for both egocentric and gravicentric alignments when roll-tilted. Two mechanisms might explain the roll-angle-dependent modulation in egocentric tasks: 1) Modulating variability in estimated ocular torsion, which reflects the roll-dependent precision of otolith signals, affects the precision of estimating the line orientation relative to the head; this hypothesis predicts that variability modulation is restricted to vision-dependent alignments. 2) Estimated body-longitudinal reflects the roll-dependent variability of perceived earth-vertical. Gravicentric cues are thereby integrated regardless of the task's reference frame. To test the two hypotheses the visual paradigm was repeated using a rod instead (haptic paradigm). As with the visual paradigm, precision significantly decreased with increasing head roll for both tasks. These findings propose that the CNS integrates input coded in a gravicentric frame to solve egocentric tasks. In analogy to gravicentric tasks, where trial-to-trial variability is mainly influenced by the properties of the otolith afferents, egocentric tasks may also integrate

Long-lasting amelioration of walking trajectory in neglect after prismatic adaptation

Directory of Open Access Journals (Sweden)

Marco eRabuffetti

2013-07-01

Full Text Available In the present investigation we explored the effect of prismatic adaptation (PA applied to the upper right limb on the walking trajectory of a neglect patient with more severe neglect in far than in near space. The patient was asked to bisect a line fixed to the floor by walking across it before and after four sessions of PA distributed over a time frame of 67 days. Gait path was analysed by means of an optoelectronic motion analysis system.The walking trajectory improved following PA and the result was maintained at follow-up, fifteen months after treatment. The improvement was greater for the predicted bisection error (estimated on the basis of the trajectory extrapolated from the first walking step then for the observed bisection error (measured at line crossing.These results show that PA may act on high level spatial representation of gait trajectory rather than on lower level sensory-motor gait components and suggest that PA may have a long lasting rehabilitative effect on neglect patients showing a deviated walking trajectory.

Allocating time to future tasks: the effect of task segmentation on planning fallacy bias.

Science.gov (United States)

Forsyth, Darryl K; Burt, Christopher D B

2008-06-01

The scheduling component of the time management process was used as a "paradigm" to investigate the allocation of time to future tasks. In three experiments, we compared task time allocation for a single task with the summed time allocations given for each subtask that made up the single task. In all three, we found that allocated time for a single task was significantly smaller than the summed time allocated to the individual subtasks. We refer to this as the segmentation effect. In Experiment 3, we asked participants to give estimates by placing a mark on a time line, and found that giving time allocations in the form of rounded close approximations probably does not account for the segmentation effect. We discuss the results in relation to the basic processes used to allocate time to future tasks and the means by which planning fallacy bias might be reduced.

Making Time for Nature: Visual Exposure to Natural Environments Lengthens Subjective Time Perception and Reduces Impulsivity.

Directory of Open Access Journals (Sweden)

Meredith S Berry

Full Text Available Impulsivity in delay discounting is associated with maladaptive behaviors such as overeating and drug and alcohol abuse. Researchers have recently noted that delay discounting, even when measured by a brief laboratory task, may be the best predictor of human health related behaviors (e.g., exercise currently available. Identifying techniques to decrease impulsivity in delay discounting, therefore, could help improve decision-making on a global scale. Visual exposure to natural environments is one recent approach shown to decrease impulsive decision-making in a delay discounting task, although the mechanism driving this result is currently unknown. The present experiment was thus designed to evaluate not only whether visual exposure to natural (mountains, lakes relative to built (buildings, cities environments resulted in less impulsivity, but also whether this exposure influenced time perception. Participants were randomly assigned to either a natural environment condition or a built environment condition. Participants viewed photographs of either natural scenes or built scenes before and during a delay discounting task in which they made choices about receiving immediate or delayed hypothetical monetary outcomes. Participants also completed an interval bisection task in which natural or built stimuli were judged as relatively longer or shorter presentation durations. Following the delay discounting and interval bisection tasks, additional measures of time perception were administered, including how many minutes participants thought had passed during the session and a scale measurement of whether time "flew" or "dragged" during the session. Participants exposed to natural as opposed to built scenes were less impulsive and also reported longer subjective session times, although no differences across groups were revealed with the interval bisection task. These results are the first to suggest that decreased impulsivity from exposure to natural as

When predictions take control: The effect of task predictions on task switching performance

Directory of Open Access Journals (Sweden)

Wout eDuthoo

2012-08-01

Full Text Available In this paper, we aimed to investigate the role of self-generated predictions in the flexible control of behaviour. Therefore, we ran a task switching experiment in which participants were asked to try to predict the upcoming task in three conditions varying in switch rate (30%, 50% and 70%. Irrespective of their predictions, the colour of the target indicated which task participants had to perform. In line with previous studies (Mayr, 2006; Monsell & Mizon, 2006, the switch cost was attenuated as the switch rate increased. Importantly, a clear task repetition bias was found in all conditions, yet the task repetition prediction rate dropped from 78% over 66% to 49% with increasing switch probability in the three conditions. Irrespective of condition, the switch cost was strongly reduced in expectation of a task alternation compared to the cost of an unexpected task alternation following repetition predictions. Hence, our data suggest that the reduction in the switch cost with increasing switch probability is caused by a diminished expectancy for the task to repeat. Taken together, this paper highlights the importance of predictions in the flexible control of behaviour, and suggests a crucial role for task repetition expectancy in the context-sensitive adjusting of task switching performance.

Developmental changes in using verbal self-cueing in task-switching situations: the impact of task practice and task-sequencing demands

Science.gov (United States)

Kray, Jutta; Gaspard, Hanna; Karbach, Julia; Blaye, Agnès

2013-01-01

In this study we examined whether developmental changes in using verbal self-cueing for task-goal maintenance are dependent on the amount of task practice and task-sequencing demands. To measure task-goal maintenance we applied a switching paradigm in which children either performed only task A or B in single-task blocks or switched between them on every second trial in mixed-task blocks. Task-goal maintenance was determined by comparing the performance between both blocks (mixing costs). The influence of verbal self-cueing was measured by instructing children to either name the next task aloud or not to verbalize during task preparation. Task-sequencing demands were varied between groups whereas one group received spatial task cues to support keeping track of the task sequence, while the other group did not. We also varied by the amount of prior practice in task switching while one group of participants practiced task switching first, before performing the task naming in addition, and the other group did it vice versa. Results of our study investigating younger (8–10 years) and older children (11–13 years) revealed no age differences in beneficial effects of verbal self-cueing. In line with previous findings, children showed reduced mixing costs under task-naming instructions and under conditions of low task-sequence demands (with the presence of spatial task cues). Our results also indicated that these benefits were only obtained for those groups of children that first received practice in task switching alone with no additional verbalization instruction. These findings suggest that internal task-cueing strategies can be efficiently used in children but only if they received prior practice in the underlying task so that demands on keeping and coordinating various instructions are reduced. Moreover, children benefitted from spatial task cues for better task-goal maintenance only if no verbal task-cueing strategy was introduced first. PMID:24381566

Heuristics comparison for u-shaped assembly line balancing in the apparel factory

Directory of Open Access Journals (Sweden)

Nuchsara Kriengkorakot

2014-06-01

Full Text Available In recent year, many industries have adopted a Just-in-time (JIT approach to manufacturing. One of the important changes resulting from JIT implementation is the replacement of the traditional straight lines with Ushaped assembly lines. The important characteristic of these new configurations is that multiskilled workers perform various tasks of different stations along the production line. This research is to improve the assembly line balancing in apparel factory in case study of T-shirt style 53287. The efficiency of production line was 55.48%, the factory balanced line with the traditional method in straight line. Then, the u-shaped assembly line balancing problem (UALBP is to be performed instead of straight line. By using the heuristics of Maximum Task Time, Minimum Task Time, Maximum Ranked Positional Weight (RPWmax and Greedy Randomized to determine the optimal solutions related to the number of stations and line efficiency. The results indicate that two heuristics have given the good solution which have produced by the use of Maximum Task Time and Greedy Randomized. The minimum number of stations have reduced from 17 stations to 11 stations in UALB and the line efficiency was increased from 55.48% to 85.75%. The U-line configuration frequently improves the line efficiency and has fewer work stations compared to the traditional lines.

Quasi-min-max Fuzzy MPC of UTSG Water Level Based on Off-Line Invariant Set

Science.gov (United States)

Liu, Xiangjie; Jiang, Di; Lee, Kwang Y.

2015-10-01

In a nuclear power plant, the water level of the U-tube steam generator (UTSG) must be maintained within a safe range. Traditional control methods encounter difficulties due to the complexity, strong nonlinearity and “swell and shrink” effects, especially at low power levels. A properly designed robust model predictive control can well solve this problem. In this paper, a quasi-min-max fuzzy model predictive controller is developed for controlling the constrained UTSG system. While the online computational burden could be quite large for the real-time control, a bank of ellipsoid invariant sets together with the corresponding feedback control laws are obtained by off-line solving linear matrix inequalities (LMIs). Based on the UTSG states, the online optimization is simplified as a constrained optimization problem with a bisection search for the corresponding ellipsoid invariant set. Simulation results are given to show the effectiveness of the proposed controller.

Whole-body biodistribution and radiation dosimetry in monkeys and humans of the phosphodiesterase 4 radioligand [11C](R)-rolipram: comparison of two-dimensional planar, bisected and quadrisected image analyses

International Nuclear Information System (INIS)

Sprague, David R.; Fujita, Masahiro; Ryu, Yong Hoon; Liow, Jeih-San; Pike, Victor W.; Innis, Robert B.

2008-01-01

Introduction: [ 11 C](R)-Rolipram is a selective radioligand for positron emission tomography (PET) imaging of phosphodiesterase 4, an enzyme that metabolizes 3',5'-cyclic adenosine monophosphate. The aim of this study was to estimate the human radiation absorbed dose of the radioligand based on its biodistribution in both monkeys and humans. Methods: Whole-body PET images were acquired for 2 h after injecting [ 11 C](R)-rolipram in eight healthy humans and three monkeys. The simple method of using a single two-dimensional (2D) planar image was compared to more time-consuming methods that used two (bisected) or four (quadrisected) tomographic images in the anteroposterior direction. Results: Effective dose was 4.8 μGy/MBq based on 2D planar images. The effective dose was only slightly lower by 1% and 5% using the bisected and quadrisected images, respectively. Nevertheless, the two tomographic methods may have more accurately estimated the exposure of some organs (e.g., kidneys) that are asymmetrically located in the body or have radioactivity that appears to overlap on 2D planar images. Monkeys had a different biodistribution pattern compared to humans (e.g., greater urinary excretion) such that their data overestimated the effective dose in humans by 40%. Conclusions: The effective dose of [ 11 C](R)-rolipram was modest and comparable to that of other 11 C-labeled radioligands. The simple and far less time-consuming 2D planar method provided accurate and somewhat more conservative estimates of effective dose than the two tomographic methods. Although monkeys are commonly used to estimate human radiation exposures, their data gave a considerable overestimation for this radioligand

Testing the scalar expectancy theory (SET) and the learning-to-time model (LeT) in a double bisection task.

Science.gov (United States)

Machado, Armando; Pata, Paulo

2005-02-01

Two theories of timing, scalar expectancy theory (SET) and learning-to-time (LeT), make substantially different assumptions about what animals learn in temporal tasks. In a test of these assumptions, pigeons learned two temporal discriminations. On Type 1 trials, they learned to choose a red key after a 1-sec signal and a green key after a 4-sec signal; on Type 2 trials, they learned to choose a blue key after a 4-sec signal and a yellow key after either an 8-sec signal (Group 8) or a 16-sec signal (Group 16). Then, the birds were exposed to signals 1 sec, 4 sec, and 16 sec in length and given a choice between novel key combinations (red or green vs. blue or yellow). The choice between the green key and the blue key was of particular significance because both keys were associated with the same 4-sec signal. Whereas SET predicted no effect of the test signal duration on choice, LeT predicted that preference for green would increase monotonically with the length of the signal but would do so faster for Group 8 than for Group 16. The results were consistent with LeT, but not with SET.

Fractions, Number Lines, Third Graders

Science.gov (United States)

Cramer, Kathleen; Ahrendt, Sue; Monson, Debra; Wyberg, Terry; Colum, Karen

2017-01-01

The Common Core State Standards for Mathematics (CCSSM) (CCSSI 2010) outlines ambitious goals for fraction learning, starting in third grade, that include the use of the number line model. Understanding and constructing fractions on a number line are particularly complex tasks. The current work of the authors centers on ways to successfully…

Children's mathematical performance: five cognitive tasks across five grades.

Science.gov (United States)

Moore, Alex M; Ashcraft, Mark H

2015-07-01

Children in elementary school, along with college adults, were tested on a battery of basic mathematical tasks, including digit naming, number comparison, dot enumeration, and simple addition or subtraction. Beyond cataloguing performance to these standard tasks in Grades 1 to 5, we also examined relationships among the tasks, including previously reported results on a number line estimation task. Accuracy and latency improved across grades for all tasks, and classic interaction patterns were found, for example, a speed-up of subitizing and counting, increasingly shallow slopes in number comparison, and progressive speeding of responses especially to larger addition and subtraction problems. Surprisingly, digit naming was faster than subitizing at all ages, arguing against a pre-attentive processing explanation for subitizing. Estimation accuracy and speed were strong predictors of children's addition and subtraction performance. Children who gave exponential responses on the number line estimation task were slower at counting in the dot enumeration task and had longer latencies on addition and subtraction problems. The results provided further support for the importance of estimation as an indicator of children's current and future mathematical expertise. Copyright © 2015 Elsevier Inc. All rights reserved.

Wireless Sensor Network for Electric Transmission Line Monitoring

Energy Technology Data Exchange (ETDEWEB)

Alphenaar, Bruce

2009-06-30

Generally, federal agencies tasked to oversee power grid reliability are dependent on data from grid infrastructure owners and operators in order to obtain a basic level of situational awareness. Since there are many owners and operators involved in the day-to-day functioning of the power grid, the task of accessing, aggregating and analyzing grid information from these sources is not a trivial one. Seemingly basic tasks such as synchronizing data timestamps between many different data providers and sources can be difficult as evidenced during the post-event analysis of the August 2003 blackout. In this project we investigate the efficacy and cost effectiveness of deploying a network of wireless power line monitoring devices as a method of independently monitoring key parts of the power grid as a complement to the data which is currently available to federal agencies from grid system operators. Such a network is modeled on proprietary power line monitoring technologies and networks invented, developed and deployed by Genscape, a Louisville, Kentucky based real-time energy information provider. Genscape measures transmission line power flow using measurements of electromagnetic fields under overhead high voltage transmission power lines in the United States and Europe. Opportunities for optimization of the commercial power line monitoring technology were investigated in this project to enable lower power consumption, lower cost and improvements to measurement methodologies. These optimizations were performed in order to better enable the use of wireless transmission line monitors in large network deployments (perhaps covering several thousand power lines) for federal situational awareness needs. Power consumption and cost reduction were addressed by developing a power line monitor using a low power, low cost wireless telemetry platform known as the ''Mote''. Motes were first developed as smart sensor nodes in wireless mesh networking applications

ERP correlates of social conformity in a line judgment task

Directory of Open Access Journals (Sweden)

Chen Jing

2012-05-01

Full Text Available Abstract Background Previous research showed that individuals have a natural tendency to conform to others. This study investigated the temporal characteristics of neural processing involved in social conformity by recording participants’ brain potentials in performing a line judgment task. After making his initial choice, a participant was presented with the choices of four same-sex group members, which could be congruent or highly or moderately incongruent with the participant’s own choice. The participant was then immediately given a second opportunity to respond to the same stimulus. Results Participants were more likely to conform to the group members by changing their initial choices when these choices were in conflict with the group’s choices, and this behavioral adjustment occurred more often as the level of incongruence increased. Electrophysiologically, group choices that were incongruent with the participant’s choice elicited more negative-going medial frontal negativity (MFN, a component associated with processing expectancy violation, than those that were congruent with the participant’s choice, and the size of this effect increased as the level of incongruence increased. Moreover, at both levels of incongruence, the MFN responses were more negative-going for incongruent trials in which participants subsequently performed behavioral adjustment than for trials in which they stuck to their initial choices. Furthermore, over individual participants, participants who were more likely to conform to others (i.e., changing their initial choices exhibited stronger MFN effect than individuals who were more independent. Conclusions These findings suggest that incongruence with group choices or opinions can elicit brain responses that are similar to those elicited by violation of non-social expectancy in outcome evaluation and performance monitoring, and these brain signals are utilized in the following behavioral adjustment. The

The role of physical content in piagetian spatial tasks: Sex differences in spatial knowledge?

Science.gov (United States)

Golbeck, Susan L.

Sex-related differences on Piagetian horizontality (water level) and verticality (plumb line) tasks were examined in 64 college students. It was hypothesized that females' difficulties on these Euclidean spatial problems are due not to differences in underlying spatial competence, but rather to differences in knowledge of task specific information about the physical properties of water levels and plumb lines. This was tested by presenting subjects with the standard water level and plumb line problems and also modified problems not requiring knowledge of physical principles (i.e., drawing straight up and down or straight across lines inside tipped rectangles). While males were expected to outperform females on the standard tasks, no sex differences were expected on the modified tasks. Results of an ANOVA on scores for horizontality and verticality each showed main effects for sex and task version but failed to reveal the hypothesized interaction. However, performance on the Euclidean spatial tasks was also considered in terms of overall success versus failure. While males were more successful than females in the standard format, males and females were equally successful in the modified, nonphysical, format. Hence, college aged males and females generally do not differ in spatial competence although they may be differentially influenced by task content. Findings are discussed in terms of their implications for theory and practice. It is emphasized that science educators must be especially aware of such task influences for females so that performance deficits are not mistaken for competence deficits.

Keeping your distance: attentional withdrawal in individuals who show physiological signs of social discomfort.

Science.gov (United States)

Szpak, Ancret; Loetscher, Tobias; Churches, Owen; Thomas, Nicole A; Spence, Charles J; Nicholls, Michael E R

2015-04-01

Being in close social proximity to a stranger is generally perceived to be an uncomfortable experience, which most people seek to avoid. In circumstances where crowding is unavoidable, however, people may seek to withdraw their attention from the other person. This study examined whether social discomfort, as indexed by electrodermal activity, is related to a withdrawal of attention in 28 (m=8, f=20) university students. Students performed a radial line bisection task while alone or together with a stranger facing them. Physiological arousal was indexed by a wrist monitor, which recorded electrodermal activity. Correlational analyses showed that individuals who displayed physiological discomfort when together showed a withdrawal of the perceived midpoint of the line towards them (and away from the stranger). Conversely, individuals who showed no discomfort exhibited an expansion of the perceived midpoint away from them. We propose that participants shift their attention away from the stranger to increase interpersonal distance and reduce anxiety/arousal. Copyright © 2014 Elsevier Ltd. All rights reserved.

Task representation in individual and joint settings

Directory of Open Access Journals (Sweden)

Wolfgang ePrinz

2015-05-01

Full Text Available This paper outlines a framework for task representation and discusses applications to interference tasks in individual and joint settings. The framework is derived from the Theory of Event Coding. This theory regards task sets as transient assemblies of event codes in which stimulus and response codes interact and shape each other in particular ways. On the one hand, stimulus and response codes compete with each other within their respective subsets (horizontal interactions. On the other hand, stimulus and response code cooperate with each other (vertical interactions. Code interactions instantiating competition and cooperation apply to two time scales: on-line performance (i.e., doing the task and off-line implementation (i.e., setting the task. Interference arises when stimulus and response codes overlap in features that are irrelevant for stimulus identification, but relevant for response selection. To resolve this dilemma, the feature profiles of event codes may become restructured in various ways. The framework is applied to three kinds of interference paradigms. Special emphasis is given to joint settings where tasks are shared between two participants. Major conclusions derived from these applications include: (1 Response competition is the chief driver of interference. Likewise, different modes of response competition give rise to different patterns of interference. (2 The type of features in which stimulus and response codes overlap is also a crucial factor. Different types of such features give likewise rise to different patterns of interference. (3 Task sets for joint settings conflate intraindividual conflicts between responses (what, with interindividual conflicts between responding agents (whom. Features of response codes may, therefore, not only address responses, but also responding agents (both physically and socially.

Task representation in individual and joint settings

Science.gov (United States)

Prinz, Wolfgang

2015-01-01

This paper outlines a framework for task representation and discusses applications to interference tasks in individual and joint settings. The framework is derived from the Theory of Event Coding (TEC). This theory regards task sets as transient assemblies of event codes in which stimulus and response codes interact and shape each other in particular ways. On the one hand, stimulus and response codes compete with each other within their respective subsets (horizontal interactions). On the other hand, stimulus and response code cooperate with each other (vertical interactions). Code interactions instantiating competition and cooperation apply to two time scales: on-line performance (i.e., doing the task) and off-line implementation (i.e., setting the task). Interference arises when stimulus and response codes overlap in features that are irrelevant for stimulus identification, but relevant for response selection. To resolve this dilemma, the feature profiles of event codes may become restructured in various ways. The framework is applied to three kinds of interference paradigms. Special emphasis is given to joint settings where tasks are shared between two participants. Major conclusions derived from these applications include: (1) Response competition is the chief driver of interference. Likewise, different modes of response competition give rise to different patterns of interference; (2) The type of features in which stimulus and response codes overlap is also a crucial factor. Different types of such features give likewise rise to different patterns of interference; and (3) Task sets for joint settings conflate intraindividual conflicts between responses (what), with interindividual conflicts between responding agents (whom). Features of response codes may, therefore, not only address responses, but also responding agents (both physically and socially). PMID:26029085

Imitation of in-group versus out-group members' facial expressions of anger: a test with a time perception task.

Science.gov (United States)

Mondillon, Laurie; Niedenthal, Paula M; Gil, Sandrine; Droit-Volet, Sylvie

2007-01-01

This research investigated the automatic imitation of facial expressions of anger by in-group and out-group members, using a temporal estimation task. Individuals typically overestimate duration represented by angry faces, probably due to increases in arousal (Droit-Volet, Brunot, & Niedenthal, 2004). Overestimation is not observed when imitation of the facial expressions is inhibited, suggesting that embodied simulation mediates the changes in arousal (Effron, Niedenthal, Gil, & Droit-Volet, 2006). This method thus provides an implicit measure of imitation and was used to test the hypothesis that individuals imitate in-group, but not out-group members' facial expressions of emotion. In separate studies Chinese and French Caucasian participants were presented with short (400 ms) and long (1600 ms) standard durations in a temporal bisection task. They then categorized standard and intermediate durations, represented by angry and neutral faces, in terms of similarity to the short and long standard durations. Half of the face stimuli were Chinese, and half Caucasian. Results revealed a bias in the temporal perception of emotion for the Caucasian participants when they were presented with Caucasian facial expressions and not Chinese ones. In contrast, this bias in time perception was observed when Chinese individuals imitated faces of both in- and out-group members. The results of the Chinese participants are interpreted in terms of familiarity with and motivations to understand the emotional expressions of members of a host culture.

Serial or overlapping processing in multitasking as individual preference: Effects of stimulus preview on task switching and concurrent dual-task performance.

Science.gov (United States)

Reissland, Jessika; Manzey, Dietrich

2016-07-01

Understanding the mechanisms and performance consequences of multitasking has long been in focus of scientific interest, but has been investigated by three research lines more or less isolated from each other. Studies in the fields of the psychological refractory period, task switching, and interruptions have scored with a high experimental control, but usually do not give participants many degrees of freedom to self-organize the processing of two concurrent tasks. Individual strategies as well as their impact on efficiency have mainly been neglected. Self-organized multitasking has been investigated in the field of human factors, but primarily with respect to overall performance without detailed investigation of how the tasks are processed. The current work attempts to link aspects of these research lines. All of them, explicitly or implicitly, provide hints about an individually preferred type of task organization, either more cautious trying to work strictly serially on only one task at a time or more daring with a focus on task interleaving and, if possible, also partially overlapping (parallel) processing. In two experiments we investigated different strategies of task organization and their impact on efficiency using a new measure of overall multitasking efficiency. Experiment 1 was based on a classical task switching paradigm with two classification tasks, but provided one group of participants with a stimulus preview of the task to switch to next, enabling at least partial overlapping processing. Indeed, this preview led to a reduction of switch costs and to an increase of dual-task efficiency, but only for a subgroup of participants. They obviously exploited the possibility of overlapping processing, while the others worked mainly serially. While task-sequence was externally guided in the first experiment, Experiment 2 extended the approach by giving the participants full freedom of task organization in concurrent performance of the same tasks. Fine

The task of control digital image compression

OpenAIRE

TASHMANOV E.B.; МАМАTOV М.S.

2014-01-01

In this paper we consider the relationship of control tasks and image compression losses. The main idea of this approach is to allocate structural lines simplified image and further compress the selected data

Duration Judgments for Verbal Stimuli: Effects of Emotion, Attention, and Memory Encoding

OpenAIRE

Johnson, Laura Wendy

2014-01-01

In six experiments, this dissertation investigated duration judgments for verbal stimuli, testing predictions of information-processing models of time perception. Experiments 1, 2, and 3 explored the effects of low-valence, high-arousal taboo words on the perception of time. The results revealed that durations of taboo words were underestimated compared to neutral words in prospective timing tasks, including the temporal bisection task in Experiment 1 and the ordinality comparison procedure ...

Tactile feedback improves auditory spatial localization

Directory of Open Access Journals (Sweden)

Monica eGori

2014-10-01

Full Text Available Our recent studies suggest that congenitally blind adults have severely impaired thresholds in an auditory spatial-bisection task, pointing to the importance of vision in constructing complex auditory spatial maps (Gori et al., 2014. To explore strategies that may improve the auditory spatial sense in visually impaired people, we investigated the impact of tactile feedback on spatial auditory localization in 48 blindfolded sighted subjects. We measured auditory spatial bisection thresholds before and after training, either with tactile feedback, verbal feedback or no feedback. Audio thresholds were first measured with a spatial bisection task: subjects judged whether the second sound of a three sound sequence was spatially closer to the first or the third sound. The tactile-feedback group underwent two audio-tactile feedback sessions of 100 trials, where each auditory trial was followed by the same spatial sequence played on the subject’s forearm; auditory spatial bisection thresholds were evaluated after each session. In the verbal-feedback condition, the positions of the sounds were verbally reported to the subject after each feedback trial. The no-feedback group did the same sequence of trials, with no feedback. Performance improved significantly only after audio-tactile feedback. The results suggest that direct tactile feedback interacts with the auditory spatial localization system, possibly by a process of cross-sensory recalibration. Control tests with the subject rotated suggested that this effect occurs only when the tactile and acoustic sequences are spatially coherent. Our results suggest that the tactile system can be used to recalibrate the auditory sense of space. These results encourage the possibility of designing rehabilitation programs to help blind persons establish a robust auditory sense of space, through training with the tactile modality.

Exploring the repetition bias in voluntary task switching.

Science.gov (United States)

Mittelstädt, Victor; Dignath, David; Schmidt-Ott, Magdalena; Kiesel, Andrea

2018-01-01

In the voluntary task-switching paradigm, participants are required to randomly select tasks. We reasoned that the consistent finding of a repetition bias (i.e., participants repeat tasks more often than expected by chance) reflects reasonable adaptive task selection behavior to balance the goal of random task selection with the goals to minimize the time and effort for task performance. We conducted two experiments in which participants were provided with variable amount of preview for the non-chosen task stimuli (i.e., potential switch stimuli). We assumed that switch stimuli would initiate some pre-processing resulting in improved performance in switch trials. Results showed that reduced switch costs due to extra-preview in advance of each trial were accompanied by more task switches. This finding is in line with the characteristics of rational adaptive behavior. However, participants were not biased to switch tasks more often than chance despite large switch benefits. We suggest that participants might avoid effortful additional control processes that modulate the effects of preview on task performance and task choice.

Visuospatial performance on an internet line judgment task and potential hormonal markers: sex, sexual orientation, and 2D:4D.

Science.gov (United States)

Collaer, Marcia L; Reimers, Stian; Manning, John T

2007-04-01

We investigated whether performance on a visuospatial line judgment task, the Judgment of Line Angle and Position-15 test (JLAP-15), showed evidence of sensitivity to early sex steroid exposure by examining how it related to sex, as well as to sexual orientation and 2D:4D digit ratios. Participants were drawn from a large Internet study with over 250,000 participants. In the main sample (ages 12-58 years), males outperformed females on the JLAP-15, showing a moderate effect size for sex. In agreement with a prenatal sex hormone hypothesis, line judgment accuracy in adults related to 2D:4D and sexual orientation, both of which are postulated to be influenced by early steroids. In both sexes, better visuospatial performance was associated with lower (more male-typical) digit ratios. For men, heterosexual participants outperformed homosexual/bisexual participants on the JLAP-15 and, for women, homosexual/bisexual participants outperformed heterosexual participants. In children aged 8-10 years, presumed to be a largely prepubertal group, boys also outperformed girls. These findings are consistent with the hypothesis that visuospatial ability is influenced by early sex steroids, although they do not rule out alternative explanations or additional influences. More broadly, such results support a prenatal sex hormone hypothesis that degree of androgen exposure may influence the neural circuitry underlying cognition (visuospatial ability) and sexual orientation as well as aspects of somatic (digit ratio) development.

Task conflict in the Stroop task: When Stroop interference decreases as Stroop facilitation increases in a low task conflict context

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Benjamin Andrew Parris

2014-10-01

Full Text Available In the present study participants completed two blocks of the Stroop task, one in which the Response-Stimulus Interval (RSI was 3500ms and one in which RSI was 200ms. It was expected that, in line with previous research, the shorter RSI would induce a low Task Conflict context by increasing focus on the colour identification goal in the Stroop task. Based on previous research showing the role of Task Conflict in the presence or absence Stroop facilitation, this was expected to lead to the novel finding of an increase in facilitation and simultaneous decrease in interference. Such a finding would be problematic for models of Stroop effects that predict these indices of performance should be affected in tandem. A crossover interaction is reported supporting these predictions. As predicted, the shorter RSI resulted in incongruent and congruent trial RTs decreasing relative to a static neutral baseline condition; hence interference decreased as facilitation increased. An explanatory model (expanding on the work of Goldfarb, Henik and colleagues is presented that: 1 Shows how under certain conditions the predictions from single mechanism models hold true (i.e. when Task conflict is held constant; 2 Shows how it is possible that interference can be affected by an experimental manipulation that leaves facilitation apparently untouched and; 3 Predicts that facilitation cannot be independently affected by an experimental manipulation.

On-line data analysis and monitoring for H1 drift chambers

International Nuclear Information System (INIS)

Duellmann, D.

1992-01-01

The on-line monitoring, slow control and calibration of the H1 central jet chamber uses a VME multiprocessor system to perform the analysis and a connected Macintosh computer as graphical interface to the operator on shift. Tasks of this system are: Analysis of event data including on-line track search; on-line calibration from normal events and testpulse events; control of the high voltage and monitoring of settings and currents; monitoring of temperature, pressure and mixture of the chambergas. A program package is described which controls the dataflow between data aquisition, different VME CPUs and Macintosh. It allows to run off-line style programs for the different tasks. (orig.)

On-line data analysis and monitoring for H1 drift chambers

Science.gov (United States)

Düllmann, Dirk

1992-05-01

The on-line monitoring, slow control and calibration of the H1 central jet chamber uses a VME multiprocessor system to perform the analysis and a connected Macintosh computer as graphical interface to the operator on shift. Task of this system are: - analysis of event data including on-line track search, - on-line calibration from normal events and testpulse events, - control of the high voltage and monitoring of settings and currents, - monitoring of temperature, pressure and mixture of the chambergas. A program package is described which controls the dataflow between data aquisition, differnt VME CPUs and Macintosh. It allows to run off-line style programs for the different tasks.

ASSEMBLY LINE BALANCING in a CLOTHING COMPANY

Directory of Open Access Journals (Sweden)

HASNALCACI Kubra

2017-05-01

Full Text Available Assembly lines take the attention of researchers and companies because of its great effect on efficiency. Efficiency in assembly lines has an important role on cost and quality which are the basic fundamentals of competition. Assembly lines contain a number of workstations and tasks (jobs are processed in these stations and are moved from station to station. The tasks are assigned to each station regarding a cycle time. The cycle time is the maximum available time for the production of a job at any workstation. The assingning of jobs to workstations is based on the objective of minimizing the workflow among the workstations, reducing the throughput time as well as the work in progress and thus increasing productivity. If the jobs are not allocated in balance, this will cause idle workstations and waste of workforce besides the loss of overall efficiency. In this study, an assebly line balancing problem was examined for a five pocket denim trousers in a clothing company. Firstly, priority associations and standard durations of operations of denim trousers were determined. Then, assembly line balancing study was carried out by using ranked positional weights assembly line balancing method developed by Helgeson and Birnie to increase the production in a clothing company manufacturing five pocket denim trousers.

Children's Early Mental Number Line: Logarithmic or Decomposed Linear?

Science.gov (United States)

Moeller, Korbinean; Pixner, Silvia; Kaufmann, Liane; Nuerk, Hans-Christoph

2009-01-01

Recently, the nature of children's mental number line has received much investigation. In the number line task, children are required to mark a presented number on a physical number line with fixed endpoints. Typically, it was observed that the estimations of younger/inexperienced children were accounted for best by a logarithmic function, whereas…

Task force for integral test of High Energy nuclear data

Energy Technology Data Exchange (ETDEWEB)

Oyama, Yukio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-11-01

According to completion of the JENDL-High Energy file for neutron nuclear cross sections up to 50 MeV, a task force for integral test of high energy nuclear data was organized to discuss a guide line for integral test activities. A status of existing differential and integral experiments and how to perform such a test were discussed in the task force. Here the purpose and outline of the task force is explained with some future problems raised in discussion among the task member. (author)

High-definition television evaluation for remote handling task performance

International Nuclear Information System (INIS)

Fujita, Y.; Omori, E.; Hayashi, S.; Draper, J.V.; Herndon, J.N.

1986-01-01

In a plant that employs remote handling techniques for equipment maintenance, operators perform maintenance tasks primarily by using the information from television systems. The efficiency of the television system has a significant impact on remote maintenance task performance. High-definition television (HDTV) transmits a video image with more than twice the number of horizontal scan lines as standard-resolution television (1125 for HDTV to 525 for standard-resolution NTSC television). The added scan lines dramatically improve the resolution of images on the HDTV monitors. This paper describes experiments designed to evaluate the impact of HDTV on the performance of typical remote tasks. The experiments described in this paper compared the performance of four operators using HDTV with their performance while using other television systems. The experiments included four television systems: (a) high-definition color television, (b) high-definition monochromatic television, (c) standard-resolution monochromatic television, and (d) standard-resolution stereoscopic monochromatic television

Development of Live-working Robot for Power Transmission Lines

Science.gov (United States)

Yan, Yu; Liu, Xiaqing; Ren, Chengxian; Li, Jinliang; Li, Hui

2017-07-01

Dream-I, the first reconfigurable live-working robot for power transmission lines successfully developed in China, has the functions of autonomous walking on lines and accurately positioning. This paper firstly described operation task and object of the robot; then designed a general platform, an insulator replacement end and a drainage plate bolt fastening end of the robot, presented a control system of the robot, and performed simulation analysis on operation plan of the robot; and finally completed electrical field withstand voltage tests in a high voltage hall as well as online test and trial on actual lines. Experimental results show that by replacing ends of manipulators, the robot can fulfill operation tasks of live replacement of suspension insulators and live drainage plate bolt fastening.

Unbounding the mental number line – New evidence on children’s spatial representation of numbers

Directory of Open Access Journals (Sweden)

Tanja eLink

2014-01-01

Full Text Available Number line estimation (i.e., indicating the position of a given number on a physical line is a standard assessment of children’s spatial representation of number magnitude. Importantly, there is an ongoing debate on the question in how far the bounded task version with start and endpoint given (e.g., 0 and 100 might induce specific estimation strategies and thus may not allow for unbiased inferences on the underlying representation. Recently, a new unbounded version of the task was suggested with only the start point and a unit fixed (e.g., the distance from 0 to 1. In adults this task provided a less biased index of the spatial representation of number magnitude. Yet, so far there are no children data available for the unbounded number line estimation task. Therefore, we conducted a cross-sectional study on primary school children performing both, the bounded and the unbounded version of the task. We observed clear evidence for systematic strategic influences (i.e., the consideration of reference points in the bounded number line estimation task for children older than grade two whereas there were no such indications for the unbounded version for any one of the age groups. In summary, the current data corroborate the unbounded number line estimation task to be a valuable tool for assessing children's spatial representation of number magnitude in a systematic and unbiased manner. Yet, similar results for the bounded and the unbounded version of the task for first- and second-graders may indicate that both versions of the task might assess the same underlying representation for relatively younger children - at least in number ranges familiar to the children assessed. This is of particular importance for inferences about the nature and development of children's magnitude representation.

Graphical programming of telerobotic tasks

International Nuclear Information System (INIS)

Small, D.E.; McDonald, M.J.

1997-01-01

With a goal of producing faster, safer, and cheaper technologies for nuclear waste cleanup, Sandia is actively developing and extending intelligent systems technologies. Graphical Programming is a key technology for robotic waste cleanup that Sandia is developing for this goal. This paper describes Sancho, Sandia most advanced Graphical Programming supervisory software. Sancho, now operational on several robot systems, incorporates all of Sandia's recent advances in supervisory control. Sancho, developed to rapidly apply Graphical Programming on a diverse set of robot systems, uses a general set of tools to implement task and operational behavior. Sancho can be rapidly reconfigured for new tasks and operations without modifying the supervisory code. Other innovations include task-based interfaces, event-based sequencing, and sophisticated GUI design. These innovations have resulted in robot control programs and approaches that are easier and safer to use than teleoperation, off-line programming, or full automation

Exploiting impedance shaping approaches to overcome force overshoots in delicate interaction tasks

Directory of Open Access Journals (Sweden)

Loris Roveda

2016-09-01

Full Text Available The aim of the presented article is to overcome the force overshoot issue in impedance based force tracking applications. Nowadays, light-weight manipulators are involved in high-accurate force control applications (such as polishing tasks, where the force overshoot issue is critical (i.e. damaging the component causing a production waste, exploiting the impedance control. Two main force tracking impedance control approaches are described in literature: (a set-point deformation and (b variable stiffness approaches. However, no contributions are directly related to the force overshoot issue. The presented article extends both such methodologies to analytically achieve the force overshoots avoidance in interaction tasks based on the on-line estimation of the interacting environment stiffness (available through an EKF. Both the proposed control algorithms allow to achieve a linear closed-loop dynamics for the coupled robot-environment system. Therefore, control gains can be analytically on-line calculated to achieve an over-damped closed-loop dynamics of the controlled coupled system. Control strategies have been validated in experiments, involving a KUKA LWR 4+. A probing task has been performed, representative of many industrial tasks (e.g. assembly tasks, in which a main force task direction is defined.

Realism of procedural task trainers in a pediatric emergency medicine procedures course.

Science.gov (United States)

Shefrin, Allan; Khazei, Afshin; Cheng, Adam

2015-01-01

Pediatric emergency medicine (PEM) physicians have minimal experience in life saving procedures and have turned to task trainers to learn these skills. Realism of these models is an important consideration that has received little study. PEM physicians and trainees participated in a day long procedural training course that utilized commercially available and homemade task trainers to teach pericardiocentesis, chest tube insertion, cricothyroidotomy and central line insertion. Participants rated the realism of the task trainers as part of a post-course survey. The homemade task trainers received variable realism ratings, with 91% of participants rating the pork rib chest tube model as realistic, 82% rating the gelatin pericardiocentesis mold as realistic and 36% rating the ventilator tubing cricothyroidotomy model as realistic. Commercial trainers also received variable ratings, with 45% rating the chest drain and pericardiocentesis simulator as realistic, 74% rating the crichotracheotomy trainer as realistic and 80% rating the central line insertion trainer as realistic. Task training models utilized in our course received variable realism ratings. When deciding what type of task trainer to use future courses should carefully consider the desired aspect of realism, and how it aligns with the procedural skill, balanced with cost considerations.

Musical expertise has minimal impact on dual task performance.

Science.gov (United States)

Cocchini, Gianna; Filardi, Maria Serena; Crhonkova, Marcela; Halpern, Andrea R

2017-05-01

Studies investigating effect of practice on dual task performance have yielded conflicting findings, thus supporting different theoretical accounts about the organisation of attentional resources when tasks are performed simultaneously. Because practice has been proven to reduce the demand of attention for the trained task, the impact of long-lasting training on one task is an ideal way to better understand the mechanisms underlying dual task decline in performance. Our study compared performance during dual task execution in expert musicians compared to controls with little if any musical experience. Participants performed a music recognition task and a visuo-spatial task separately (single task) or simultaneously (dual task). Both groups showed a significant but similar performance decline during dual tasks. In addition, the two groups showed a similar decline of dual task performance during encoding and retrieval of the musical information, mainly attributed to a decline in sensitivity. Our results suggest that attention during dual tasks is similarly distributed by expert and non-experts. These findings are in line with previous studies showing a lack of sensitivity to difficulty and lack of practice effect during dual tasks, supporting the idea that different tasks may rely on different and not-sharable attentional resources.

The Effects of Differential Goal Weights on the Performance of a Complex Financial Task.

Science.gov (United States)

Edmister, Robert O.; Locke, Edwin A.

1987-01-01

Determined whether people could obtain outcomes on a complex task that would be in line with differential goal weights corresponding to different aspects of the task. Bank lending officers were run through lender-simulation exercises. Five performance goals were weighted. Demonstrated effectiveness of goal setting with complex tasks, using group…

Quantitative Trait Loci in Inbred Lines

NARCIS (Netherlands)

Jansen, R.C.

2001-01-01

Quantitative traits result from the influence of multiple genes (quantitative trait loci) and environmental factors. Detecting and mapping the individual genes underlying such 'complex' traits is a difficult task. Fortunately, populations obtained from crosses between inbred lines are relatively

Common Developmental Tasks in Forming Reconstituted Families.

Science.gov (United States)

Kleinman, Judith

1979-01-01

Developmental tasks common to the formation of a reconstituted family are described, particularly the continued mourning of the old family; the formation of a solid marital relationship despite the difficulties presented by past failures and the presence of children; and the formation of sibling alliances across family lines. (Author)

On-line compensation for perturbations of a reaching movement is cerebellar dependent: support for the task dependency hypothesis.

Science.gov (United States)

Shimansky, Yury; Wang, Jian-Jun; Bauer, Richard A; Bracha, Vlastislav; Bloedel, James R

2004-03-01

Although the cerebellum has been shown to be critical for the acquisition and retention of adaptive modifications in certain reflex behaviors, this structure's role in the learning of motor skills required to execute complex voluntary goal-directed movements still is unclear. This study explores this issue by analyzing the effects of inactivating the interposed and dentate cerebellar nuclei on the adaptation required to compensate for an external elastic load applied during a reaching movement. We show that cats with these nuclei inactivated can adapt to predictable perturbations of the forelimb during a goal-directed reach by including a compensatory component in the motor plan prior to movement initiation. In contrast, when comparable compensatory modifications must be triggered on-line because the perturbations are applied in randomized trials (i.e., unpredictably), such adaptive responses cannot be executed or reacquired after the interposed and dentate nuclei are inactivated. These findings provide the first demonstration of the condition-dependent nature of the cerebellum's contribution to the learning of a specific volitional task.

Cognitive Abilities Explaining Age-Related Changes in Time Perception of Short and Long Durations

Science.gov (United States)

Zelanti, Pierre S.; Droit-Volet, Sylvie

2011-01-01

The current study investigated how the development of cognitive abilities explains the age-related changes in temporal judgment over short and long duration ranges from 0.5 to 30 s. Children (5- and 9-year-olds) as well as adults were given a temporal bisection task with four different duration ranges: a duration range shorter than 1 s, two…

What limits dual-tasking in working memory? An investigation of the effect of sub-task demand on maintenance mechanisms employed during dual-tasking

OpenAIRE

Doherty, Jason Michael

2016-01-01

A number of models of working memory have been proposed since the seminal work of Baddeley and Hitch (1974) on the Multiple Component Model (MCM). Subsequent MCM research focussed on developing a theoretical framework based on modality-specific stores that can operate in parallel during dual-tasking. The MCM can be contrasted with theories of working memory that assume an attention-based domain-general shared resource responsible for both short term retention as well as on-line...

Applying genetic algorithms for programming manufactoring cell tasks

Directory of Open Access Journals (Sweden)

Efredy Delgado

2005-05-01

Full Text Available This work was aimed for developing computational intelligence for scheduling a manufacturing cell's tasks, based manily on genetic algorithms. The manufacturing cell was modelled as beign a production-line; the makespan was calculated by using heuristics adapted from several libraries for genetic algorithms computed in C++ builder. Several problems dealing with small, medium and large list of jobs and machinery were resolved. The results were compared with other heuristics. The approach developed here would seem to be promising for future research concerning scheduling manufacturing cell tasks involving mixed batches.

How Do Different Aspects of Spatial Skills Relate to Early Arithmetic and Number Line Estimation?

Directory of Open Access Journals (Sweden)

Véronique Cornu

2017-12-01

Full Text Available The present study investigated the predictive role of spatial skills for arithmetic and number line estimation in kindergarten children (N = 125. Spatial skills are known to be related to mathematical development, but due to the construct’s non-unitary nature, different aspects of spatial skills need to be differentiated. In the present study, a spatial orientation task, a spatial visualization task and visuo-motor integration task were administered to assess three different aspects of spatial skills. Furthermore, we assessed counting abilities, knowledge of Arabic numerals, quantitative knowledge, as well as verbal working memory and verbal intelligence in kindergarten. Four months later, the same children performed an arithmetic and a number line estimation task to evaluate how the abilities measured at Time 1 predicted early mathematics outcomes. Hierarchical regression analysis revealed that children’s performance in arithmetic was predicted by their performance on the spatial orientation and visuo-motor integration task, as well as their knowledge of the Arabic numerals. Performance in number line estimation was significantly predicted by the children’s spatial orientation performance. Our findings emphasize the role of spatial skills, notably spatial orientation, in mathematical development. The relation between spatial orientation and arithmetic was partially mediated by the number line estimation task. Our results further show that some aspects of spatial skills might be more predictive of mathematical development than others, underlining the importance to differentiate within the construct of spatial skills when it comes to understanding numerical development.

Policy and programmatic implications of task shifting in Uganda: a case study

Directory of Open Access Journals (Sweden)

Dambisya Yoswa M

2012-03-01

Full Text Available Abstract Background Uganda has a severe health worker shortage and a high demand for health care services. This study aimed to assess the policy and programmatic implications of task shifting in Uganda. Methods This was a qualitative, descriptive study through 34 key informant interviews and eight (8 focus group discussions, with participants from various levels of the health system. Results Policy makers understood task shifting, but front-line health workers had misconceptions on the meaning and intention(s of task shifting. Examples were cited of task shifting within the Ugandan health system, some formalized (e.g. psychiatric clinical officers, and some informal ones (e.g. nurses inserting IV lines and initiating treatment. There was apparently high acceptance of task shifting in HIV/AIDS service delivery, with involvement of community health workers (CHW and PLWHA in care and support of AIDS patients. There was no written policy or guidelines on task shifting, but the policy environment was reportedly conducive with plans to develop a policy and guidelines on task shifting. Factors favouring task shifting included successful examples of task shifting, proper referral channels, the need for services, scarcity of skills and focused initiatives such as home based management of fever. Barriers to task shifting included reluctance to change, protection of professional turf, professional boundaries and regulations, heavy workload and high disease burden, poor planning, lack of a task shifting champion, lack of guidelines, the name task shifting itself, and unemployed health professionals. There were both positive and negative views on task shifting: the positive ones cast task shifting as one of the solutions to the dual problem of lack of skills and high demand for service, and as something that is already happening; while negative ones saw it as a quick fix intended for the poor, a threat to quality care and likely to compromise the health

Auditory and Visual Differences in Time Perception? An Investigation from a Developmental Perspective with Neuropsychological Tests

Science.gov (United States)

Zelanti, Pierre S.; Droit-Volet, Sylvie

2012-01-01

Adults and children (5- and 8-year-olds) performed a temporal bisection task with either auditory or visual signals and either a short (0.5-1.0s) or long (4.0-8.0s) duration range. Their working memory and attentional capacities were assessed by a series of neuropsychological tests administered in both the auditory and visual modalities. Results…

Memory systems, processes, and tasks: taxonomic clarification via factor analysis.

Science.gov (United States)

Bruss, Peter J; Mitchell, David B

2009-01-01

The nature of various memory systems was examined using factor analysis. We reanalyzed data from 11 memory tasks previously reported in Mitchell and Bruss (2003). Four well-defined factors emerged, closely resembling episodic and semantic memory and conceptual and perceptual implicit memory, in line with both memory systems and transfer-appropriate processing accounts. To explore taxonomic issues, we ran separate analyses on the implicit tasks. Using a cross-format manipulation (pictures vs. words), we identified 3 prototypical tasks. Word fragment completion and picture fragment identification tasks were "factor pure," tapping perceptual processes uniquely. Category exemplar generation revealed its conceptual nature, yielding both cross-format priming and a picture superiority effect. In contrast, word stem completion and picture naming were more complex, revealing attributes of both processes.

Assembly line performance and modeling

Science.gov (United States)

Rane, Arun B.; Sunnapwar, Vivek K.

2017-09-01

Automobile sector forms the backbone of manufacturing sector. Vehicle assembly line is important section in automobile plant where repetitive tasks are performed one after another at different workstations. In this thesis, a methodology is proposed to reduce cycle time and time loss due to important factors like equipment failure, shortage of inventory, absenteeism, set-up, material handling, rejection and fatigue to improve output within given cost constraints. Various relationships between these factors, corresponding cost and output are established by scientific approach. This methodology is validated in three different vehicle assembly plants. Proposed methodology may help practitioners to optimize the assembly line using lean techniques.

Photographs of manipulable objects are named more quickly than the same objects depicted as line-drawings: Evidence that photographs engage embodiment more than line-drawings.

Science.gov (United States)

Salmon, Joshua P; Matheson, Heath E; McMullen, Patricia A

2014-01-01

Previous research has shown that photographs of manipulable objects (i.e., those that can be grasped for use with one hand) are named more quickly than non-manipulable objects when they have been matched for object familiarity and age of acquisition. The current study tested the hypothesis that the amount of visual detail present in object depictions moderates these "manipulability" effects on object naming. The same objects were presented as photographs and line-drawings during a speeded naming task. Forty-six participants named 222 objects depicted in both formats. A significant object depiction (photographs versus line drawing) by manipulability interaction confirmed our hypothesis that manipulable objects are identified more quickly when shown as photographs; whereas, non-manipulable objects are identified equally quickly when shown as photographs versus line-drawings. These results indicate that factors such as surface detail and texture moderate the role of "action" and/or "manipulability" effects during object identification tasks, and suggest that photographs of manipulable objects are associated with more embodied representations of those objects than when they are depicted as line-drawings.

Agent-oriented Architecture for Task-based Information Search System

NARCIS (Netherlands)

Aroyo, Lora; de Bra, Paul M.E.; De Bra, P.; Hardman, L.

1999-01-01

The topic of the reported research discusses an agent-oriented architecture of an educational information search system AIMS - a task-based learner support system. It is implemented within the context of 'Courseware Engineering' on-line course at the Faculty of Educational Science and Technology,

Retrival experience as an accurate indicator of person identification in line-ups

Directory of Open Access Journals (Sweden)

María José Contreras

2011-07-01

Full Text Available Responses in eyewitness identification of a person in a line-up may be based on two types of recovery experiences, remember and know experiences. Remember responses involve eyewitness identification of the target person as an episodic memory task, because it implies retrieving information about the target person in the place and at the time of the event. Know responses, in contrast, engage recognition based on familiarity or perceptual facilitation, that is, as a semantic memory task. To explore the relation between retrieval experiences and recognition accuracy, 86 participants took part in a recognition task with two conditions: one with an interpolated target absent line-up and the other only with the target present line-up. Accuracy of recognition and retrieval experience was measured. The results showed that, having previously participated in a target-absent line-up, increased omissions, while the number of hits decreased. Furthermore, participants’ know responses were associated to false recognition, whilst remember responses were associated to hits in recognition. Thus, asking eyewitnesses to inform about the kind of retrieval experience in which they based their recognition responses, may serve as a reliable indicator of accuracy in recognition. Future studies are needed to investigate whether this is also the case in natural settings.

No inherent left and right side in human 'mental number line': evidence from right brain damage.

Science.gov (United States)

Aiello, Marilena; Jacquin-Courtois, Sophie; Merola, Sheila; Ottaviani, Teresa; Tomaiuolo, Francesco; Bueti, Domenica; Rossetti, Yves; Doricchi, Fabrizio

2012-08-01

Spatial reasoning has a relevant role in mathematics and helps daily computational activities. It is widely assumed that in cultures with left-to-right reading, numbers are organized along the mental equivalent of a ruler, the mental number line, with small magnitudes located to the left of larger ones. Patients with right brain damage can disregard smaller numbers while mentally setting the midpoint of number intervals. This has been interpreted as a sign of spatial neglect for numbers on the left side of the mental number line and taken as a strong argument for the intrinsic left-to-right organization of the mental number line. Here, we put forward the understanding of this cognitive disability by discovering that patients with right brain damage disregard smaller numbers both when these are mapped on the left side of the mental number line and on the right side of an imagined clock face. This shows that the right hemisphere supports the representation of small numerical magnitudes independently from their mapping on the left or the right side of a spatial-mental layout. In addition, the study of the anatomical correlates through voxel-based lesion-symptom mapping and the mapping of lesion peaks on the diffusion tensor imaging-based reconstruction of white matter pathways showed that the rightward bias in the imagined clock-face was correlated with lesions of high-level middle temporal visual areas that code stimuli in object-centred spatial coordinates, i.e. stimuli that, like a clock face, have an inherent left and right side. In contrast, bias towards higher numbers on the mental number line was linked to white matter damage in the frontal component of the parietal-frontal number network. These anatomical findings show that the human brain does not represent the mental number line as an object with an inherent left and right side. We conclude that the bias towards higher numbers in the mental bisection of number intervals does not depend on left side spatial

Line Balancing Using Largest Candidate Rule Algorithm In A Garment Industry: A Case Study

Directory of Open Access Journals (Sweden)

V. P.Jaganathan

2014-12-01

Full Text Available The emergence of fast changes in fashion has given rise to the need to shorten production cycle times in the garment industry. As effective usage of resources has a significant effect on the productivity and efficiency of production operations, garment manufacturers are urged to utilize their resources effectively in order to meet dynamic customer demand. This paper focuses specifically on line balancing and layout modification. The aim of assembly line balance in sewing lines is to assign tasks to the workstations, so that the machines of the workstation can perform the assigned tasks with a balanced loading. Largest Candidate Rule Algorithm (LCR has been deployed in this paper.

Increased timing variability in schizophrenia and bipolar disorder.

Directory of Open Access Journals (Sweden)

Amanda R Bolbecker

Full Text Available Theoretical and empirical evidence suggests that impaired time perception and the neural circuitry underlying internal timing mechanisms may contribute to severe psychiatric disorders, including psychotic and mood disorders. The degree to which alterations in temporal perceptions reflect deficits that exist across psychosis-related phenotypes and the extent to which mood symptoms contribute to these deficits is currently unknown. In addition, compared to schizophrenia, where timing deficits have been more extensively investigated, sub-second timing has been studied relatively infrequently in bipolar disorder. The present study compared sub-second duration estimates of schizophrenia (SZ, schizoaffective disorder (SA, non-psychotic bipolar disorder (BDNP, bipolar disorder with psychotic features (BDP, and healthy non-psychiatric controls (HC on a well-established time perception task using sub-second durations. Participants included 66 SZ, 37 BDNP, 34 BDP, 31 SA, and 73 HC who participated in a temporal bisection task that required temporal judgements about auditory durations ranging from 300 to 600 milliseconds. Timing variability was significantly higher in SZ, BDP, and BDNP groups compared to healthy controls. The bisection point did not differ across groups. These findings suggest that both psychotic and mood symptoms may be associated with disruptions in internal timing mechanisms. Yet unexpected findings emerged. Specifically, the BDNP group had significantly increased variability compared to controls, but the SA group did not. In addition, these deficits appeared to exist independent of current symptom status. The absence of between group differences in bisection point suggests that increased variability in the SZ and bipolar disorder groups are due to alterations in perceptual timing in the sub-second range, possibly mediated by the cerebellum, rather than cognitive deficits.

Learner-Centered Instruction (LCI): Volume IV, The Simulated Maintenance Task Environment (SMTE): A Job Specific Simulator.

Science.gov (United States)

Rifkin, Kenneth I.; And Others

The purpose of the simulated maintenance task environment is to provide a means for training and job performance testing of the flight line weapon control systems mechanic/technician for the F-111A aircraft. It provides practice in flight line equipment checkout, troubleshooting, and removal and replacement of line replaceable units in the…

Judgment of Line Orientation Depends on Gender, Education, and Type of Error

Science.gov (United States)

Caparelli-Daquer, Egas M.; Oliveira-Souza, Ricardo; Filho, Pedro F. Moreira

2009-01-01

Visuospatial tasks are particularly proficient at eliciting gender differences during neuropsychological performance. Here we tested the hypothesis that gender and education are related to different types of visuospatial errors on a task of line orientation that allowed the independent scoring of correct responses ("hits", or H) and one type of…

Significant Tasks in Training of Job-Shop Supervisors

Science.gov (United States)

Pederson, Leonard S.; Dresdow, Sally; Benson, Joy

2013-01-01

Purpose: The need for effective training of first-line supervisors is well established. Well-trained supervision is essential to our future as a country. A fundamental step in developing effective training is to develop a jobs needs assessment. In order to develop an effective needs assessment, it is necessary to know what the tasks are of…

SLC beam line error analysis using a model-based expert system

International Nuclear Information System (INIS)

Lee, M.; Kleban, S.

1988-02-01

Commissioning particle beam line is usually a very time-consuming and labor-intensive task for accelerator physicists. To aid in commissioning, we developed a model-based expert system that identifies error-free regions, as well as localizing beam line errors. This paper will give examples of the use of our system for the SLC commissioning. 8 refs., 5 figs

The Effects of Task Structures, Dynamics of Difficulty Changes, and Strategic Resource Allocation Training on Time-Sharing Performance.

Science.gov (United States)

1983-10-01

intergrated RMSE (averaged over a sliding 5-sec window) was higher than the standard. For the memory-traoking oonditions, a combined speed-accuracy score...group and .23 for the SF group as indicated by the horizontal line on the figures). In fact, the SF group actually reached the desired primary task...23 for the SF group (indicated by the horizontal line on Figure 4). The primary task of all four 5TH-Tl pairs responded to the priority instructions

The Mac'OS X command line Unix under the hood

CERN Document Server

McElhearn, Kirk

2006-01-01

The Mac command line offers a faster, easier way to accomplish many tasks. It''s also the medium for many commands that aren''t accessible using the GUI. The Mac OS X Command Line is a clear, concise, tutorial-style introduction to all the major functionality provided by the command line. It''s also packed with information the experienced users need, including little-known shortcuts and several chapters devoted to advanced topics. This is a book to get you started, but also a book you won't soon outgrow.

NAMED ENTITY RECOGNITION FROM BIOMEDICAL TEXT -AN INFORMATION EXTRACTION TASK

Directory of Open Access Journals (Sweden)

N. Kanya

2016-07-01

Full Text Available Biomedical Text Mining targets the Extraction of significant information from biomedical archives. Bio TM encompasses Information Retrieval (IR and Information Extraction (IE. The Information Retrieval will retrieve the relevant Biomedical Literature documents from the various Repositories like PubMed, MedLine etc., based on a search query. The IR Process ends up with the generation of corpus with the relevant document retrieved from the Publication databases based on the query. The IE task includes the process of Preprocessing of the document, Named Entity Recognition (NER from the documents and Relationship Extraction. This process includes Natural Language Processing, Data Mining techniques and machine Language algorithm. The preprocessing task includes tokenization, stop word Removal, shallow parsing, and Parts-Of-Speech tagging. NER phase involves recognition of well-defined objects such as genes, proteins or cell-lines etc. This process leads to the next phase that is extraction of relationships (IE. The work was based on machine learning algorithm Conditional Random Field (CRF.

On-line monitoring and inservice inspection in codes

International Nuclear Information System (INIS)

Bartonicek, J.; Zaiss, W.; Bath, H.R.

1999-01-01

The relevant regulatory codes determine the ISI tasks and the time intervals for recurrent components testing for evaluation of operation-induced damaging or ageing in order to ensure component integrity on the basis of the last available quality data. In-service quality monitoring is carried out through on-line monitoring and recurrent testing. The requirements defined by the engineering codes elaborated by various institutions are comparable, with the KTA nuclear engineering and safety codes being the most complete provisions for quality evaluation and assurance after different, defined service periods. German conventional codes for assuring component integrity provide exclusively for recurrent inspection regimes (mainly pressure tests and optical testing). The requirements defined in the KTA codes however always demanded more specific inspections relying on recurrent testing as well as on-line monitoring. Foreign codes for ensuring component integrity concentrate on NDE tasks at regular time intervals, with time intervals scope of testing activities being defined on the basis of the ASME code, section XI. (orig./CB) [de

Imaging the neural mechanisms of TMS neglect-like bias in healthy volunteers with the interleaved TMS/fMRI technique: preliminary evidence

Directory of Open Access Journals (Sweden)

Raffaella eRicci

2012-12-01

Full Text Available Applying a precisely timed pulse of Transcranial Magnetic Stimulation (TMS over the right posterior parietal cortex (PPC can produce temporary visuo-spatial neglect-like effects. Although the TMS is applied over PPC, it is not clear what other brain regions are involved. We applied TMS within a functional Magnetic Resonance Imaging (fMRI scanner to investigate brain activity during TMS induction of neglect-like bias in three healthy volunteers, while they performed a line bisection judgment task (i.e. the landmark task. Single-pulse TMS at 115% of motor threshold was applied 150 ms after the visual stimulus onset. Participants completed two different TMS/fMRI sessions while performing this task: one session while single-pulse TMS was intermittently and time-locked applied to the right PPC and a control session with TMS positioned over the vertex. Perceptual rightward bias was observed when TMS was delivered over the right PPC. During neglect-like behavior, the fMRI maps showed decreased neural activity within parieto-frontal areas which are often lesioned or dysfunctional in patients with left neglect. Vertex TMS induced behavioral effects compatible with leftward response bias and increased BOLD signal in the left caudate (a site which has been linked to response bias. These results are discussed in relation to recent findings on neural networks subserving attention in space.

Validation of an immersive virtual reality system for training near and far space neglect in individuals with stroke: a pilot study.

Science.gov (United States)

Yasuda, Kazuhiro; Muroi, Daisuke; Ohira, Masahiro; Iwata, Hiroyasu

2017-10-01

Unilateral spatial neglect (USN) is defined as impaired ability to attend and see on one side, and when present, it interferes seriously with daily life. These symptoms can exist for near and far spaces combined or independently, and it is important to provide effective intervention for near and far space neglect. The purpose of this pilot study was to propose an immersive virtual reality (VR) rehabilitation program using a head-mounted display that is able to train both near and far space neglect, and to validate the immediate effect of the VR program in both near and far space neglect. Ten USN patients underwent the VR program with a pre-post design and no control. In the virtual environment, we developed visual searching and reaching tasks using an immersive VR system. Behavioral inattention test (BIT) scores obtained pre- and immediate post-VR program were compared. BIT scores obtained pre- and post-VR program revealed that far space neglect but not near space neglect improved promptly after the VR program. This effect for far space neglect was observed in the cancelation task, but not in the line bisection task. Positive effects of the immersive VR program for far space neglect are suggested by the results of the present pilot study. However, further studies with rigorous designs are needed to validate its clinical effectiveness.

Slope and Line of Best Fit: A Transfer of Knowledge Case Study

Science.gov (United States)

Nagle, Courtney; Casey, Stephanie; Moore-Russo, Deborah

2017-01-01

This paper brings together research on slope from mathematics education and research on line of best fit from statistics education by considering what knowledge of slope students transfer to a novel task involving determining the placement of an informal line of best fit. This study focuses on two students who transitioned from placing inaccurate…

Computer-based mechanical design of overhead lines

Science.gov (United States)

Rusinaru, D.; Bratu, C.; Dinu, R. C.; Manescu, L. G.

2016-02-01

Beside the performance, the safety level according to the actual standards is a compulsory condition for distribution grids’ operation. Some of the measures leading to improvement of the overhead lines reliability ask for installations’ modernization. The constraints imposed to the new lines components refer to the technical aspects as thermal stress or voltage drop, and look for economic efficiency, too. The mechanical sizing of the overhead lines is after all an optimization problem. More precisely, the task in designing of the overhead line profile is to size poles, cross-arms and stays and locate poles along a line route so that the total costs of the line's structure to be minimized and the technical and safety constraints to be fulfilled.The authors present in this paper an application for the Computer-Based Mechanical Design of the Overhead Lines and the features of the corresponding Visual Basic program, adjusted to the distribution lines. The constraints of the optimization problem are adjusted to the existing weather and loading conditions of Romania. The outputs of the software application for mechanical design of overhead lines are: the list of components chosen for the line: poles, cross-arms, stays; the list of conductor tension and forces for each pole, cross-arm and stay for different weather conditions; the line profile drawings.The main features of the mechanical overhead lines design software are interactivity, local optimization function and high-level user-interface

Evaluation of high-definition television for remote task performance

International Nuclear Information System (INIS)

Draper, J.V.; Fujita, Y.; Herndon, J.N.

1987-04-01

High-definition television (HDTV) transmits a video image with more than twice the number (1125 for HDTV to 525 for standard-resolution TV) of horizontal scan lines that standard-resolution TV provides. The improvement in picture quality (compared to standard-resolution TV) that the extra scan lines provide is impressive. Objects in the HDTV picture have more sharply defined edges, better contrast, and more accurate reproduction of shading and color patterns than do those in the standard-resolution TV picture. Because the TV viewing system is a key component for teleoperator performance, an improvement in TV picture quality could mean an improvement in the speed and accuracy with which teleoperators perform tasks. This report describes three experiments designed to evaluate the impact of HDTV on the performance of typical remote tasks. The performance of HDTV was compared to that of standard-resolution, monochromatic TV and standard-resolution, stereoscopic, monochromatic TV in the context of judgment of depth in a televised scene, visual inspection of an object, and performance of a typical remote handling task. The results of the three experiments show that in some areas HDTV can lead to improvement in teleoperator performance. Observers inspecting a small object for a flaw were more accurate with HDTV than with either of the standard-resolution systems. High resolution is critical for detection of small-scale flaws of the type in the experiment (a scratch on a glass bottle). These experiments provided an evaluation of HDTV television for use in tasks that must be routinely performed to remotely maintain a nuclear fuel reprocessing facility. 5 refs., 7 figs., 9 tabs

Engineering Task Plan for Hose-In-Hose Transfer Lines for the Interim Stabilization Program

International Nuclear Information System (INIS)

TORRES, T.D.

2000-01-01

The document is the Engineering Task Plan for the engineering, design services, planning, project integration and management support for the design, modification, installation and testing of an over ground transfer (OGT) system to support the interim stabilization of S/SX and U Tank Farms

Quantum Walks on the Line with Phase Parameters

Science.gov (United States)

Villagra, Marcos; Nakanishi, Masaki; Yamashita, Shigeru; Nakashima, Yasuhiko

In this paper, a study on discrete-time coined quantum walks on the line is presented. Clear mathematical foundations are still lacking for this quantum walk model. As a step toward this objective, the following question is being addressed: Given a graph, what is the probability that a quantum walk arrives at a given vertex after some number of steps? This is a very natural question, and for random walks it can be answered by several different combinatorial arguments. For quantum walks this is a highly non-trivial task. Furthermore, this was only achieved before for one specific coin operator (Hadamard operator) for walks on the line. Even considering only walks on lines, generalizing these computations to a general SU(2) coin operator is a complex task. The main contribution is a closed-form formula for the amplitudes of the state of the walk (which includes the question above) for a general symmetric SU(2) operator for walks on the line. To this end, a coin operator with parameters that alters the phase of the state of the walk is defined. Then, closed-form solutions are computed by means of Fourier analysis and asymptotic approximation methods. We also present some basic properties of the walk which can be deducted using weak convergence theorems for quantum walks. In particular, the support of the induced probability distribution of the walk is calculated. Then, it is shown how changing the parameters in the coin operator affects the resulting probability distribution.

Final report on fiscal year 1992 activities for the environmental monitors line-loss study

International Nuclear Information System (INIS)

Kenoyer, J.L.

1993-01-01

The work performed on this Environmental Monitors Line-Loss Study has been performed under Contract Numbers MLW-SVV-073750 and MFH-SVV-207554. Work on the task was initiated mid-December 1991, and this report documents and summarizes the work performed through January 18, 1993. The sections included in this report summarize the work performed on the Environmental Monitors Line-Loss Study. The sections included in this report are arranged to reflect individual sub-tasks and include: descriptions of measurement systems and procedures used to obtain cascade impactor samples and laser spectrometer measurements from multiple stacks and locations; information on data acquisition, analyses, assessment, and software; discussion of the analyses and measurement results from the cascade impactor and laser spectrometer systems and software used; discussion on the development of general test methods and procedures for line-loss determinations; an overall summary and specific conclusions that can be made with regard to efforts performed on this task during FY 1992 and FY 1993. Supporting information for these sections is included in this report as appendices

Cell line name recognition in support of the identification of synthetic lethality in cancer from text

Science.gov (United States)

Kaewphan, Suwisa; Van Landeghem, Sofie; Ohta, Tomoko; Van de Peer, Yves; Ginter, Filip; Pyysalo, Sampo

2016-01-01

Motivation: The recognition and normalization of cell line names in text is an important task in biomedical text mining research, facilitating for instance the identification of synthetically lethal genes from the literature. While several tools have previously been developed to address cell line recognition, it is unclear whether available systems can perform sufficiently well in realistic and broad-coverage applications such as extracting synthetically lethal genes from the cancer literature. In this study, we revisit the cell line name recognition task, evaluating both available systems and newly introduced methods on various resources to obtain a reliable tagger not tied to any specific subdomain. In support of this task, we introduce two text collections manually annotated for cell line names: the broad-coverage corpus Gellus and CLL, a focused target domain corpus. Results: We find that the best performance is achieved using NERsuite, a machine learning system based on Conditional Random Fields, trained on the Gellus corpus and supported with a dictionary of cell line names. The system achieves an F-score of 88.46% on the test set of Gellus and 85.98% on the independently annotated CLL corpus. It was further applied at large scale to 24 302 102 unannotated articles, resulting in the identification of 5 181 342 cell line mentions, normalized to 11 755 unique cell line database identifiers. Availability and implementation: The manually annotated datasets, the cell line dictionary, derived corpora, NERsuite models and the results of the large-scale run on unannotated texts are available under open licenses at http://turkunlp.github.io/Cell-line-recognition/. Contact: sukaew@utu.fi PMID:26428294

Engineering Task Plan for Hose-In-Hose Transfer Lines for the Interim Stabilization Program

International Nuclear Information System (INIS)

RUNG, M.P.

2000-01-01

This document is the Engineering Task Plan for the engineering, design services, planning, project integration and management support for the design, modification, installation and testing of an over ground transfer (OGT) system to support the interim stabilization of nine tanks in the 241-S/SX Tank Farms

HOPE: An On-Line Piloted Handling Qualities Experiment Data Book

Science.gov (United States)

Jackson, E. B.; Proffitt, Melissa S.

2010-01-01

A novel on-line database for capturing most of the information obtained during piloted handling qualities experiments (either flight or simulated) is described. The Hyperlinked Overview of Piloted Evaluations (HOPE) web application is based on an open-source object-oriented Web-based front end (Ruby-on-Rails) that can be used with a variety of back-end relational database engines. The hyperlinked, on-line data book approach allows an easily-traversed way of looking at a variety of collected data, including pilot ratings, pilot information, vehicle and configuration characteristics, test maneuvers, and individual flight test cards and repeat runs. It allows for on-line retrieval of pilot comments, both audio and transcribed, as well as time history data retrieval and video playback. Pilot questionnaires are recorded as are pilot biographies. Simple statistics are calculated for each selected group of pilot ratings, allowing multiple ways to aggregate the data set (by pilot, by task, or by vehicle configuration, for example). Any number of per-run or per-task metrics can be captured in the database. The entire run metrics dataset can be downloaded in comma-separated text for further analysis off-line. It is expected that this tool will be made available upon request

Review of the first line supervisory positions in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Mullin, D; Mackenzie, C W [Hickling Corp. (Canada)

1995-10-01

The authors review the nature of the tasks performed by first line maintenance supervisors in three nuclear power plants. They compare these tasks to core supervisory training curriculum, supervisory job descriptions, and both the process related to performance appraisals, and the criteria applied in carrying out these performance evaluations. Recommendations have been made concerning methods of increasing the relevancy of training and improving the performance appraisal process. ( author). 5 figs.

Review of the first line supervisory positions in nuclear power plants

International Nuclear Information System (INIS)

Mullin, D.; Mackenzie, C.W.

1995-10-01

The authors review the nature of the tasks performed by first line maintenance supervisors in three nuclear power plants. They compare these tasks to core supervisory training curriculum, supervisory job descriptions, and both the process related to performance appraisals, and the criteria applied in carrying out these performance evaluations. Recommendations have been made concerning methods of increasing the relevancy of training and improving the performance appraisal process. ( author). 5 figs

Security Requirements Management in Software Product Line Engineering

Science.gov (United States)

Mellado, Daniel; Fernández-Medina, Eduardo; Piattini, Mario

Security requirements engineering is both a central task and a critical success factor in product line development due to the complexity and extensive nature of product lines. However, most of the current product line practices in requirements engineering do not adequately address security requirements engineering. Therefore, in this chapter we will propose a security requirements engineering process (SREPPLine) driven by security standards and based on a security requirements decision model along with a security variability model to manage the variability of the artefacts related to security requirements. The aim of this approach is to deal with security requirements from the early stages of the product line development in a systematic way, in order to facilitate conformance with the most relevant security standards with regard to the management of security requirements, such as ISO/IEC 27001 and ISO/IEC 15408.

A Role-Playing Game for a Software Engineering Lab: Developing a Product Line

Science.gov (United States)

Zuppiroli, Sara; Ciancarini, Paolo; Gabbrielli, Maurizio

2012-01-01

Software product line development refers to software engineering practices and techniques for creating families of similar software systems from a basic set of reusable components, called shared assets. Teaching how to deal with software product lines in a university lab course is a challenging task, because there are several practical issues that…

Active listening: task-dependent plasticity of spectrotemporal receptive fields in primary auditory cortex.

Science.gov (United States)

Fritz, Jonathan; Elhilali, Mounya; Shamma, Shihab

2005-08-01

Listening is an active process in which attentive focus on salient acoustic features in auditory tasks can influence receptive field properties of cortical neurons. Recent studies showing rapid task-related changes in neuronal spectrotemporal receptive fields (STRFs) in primary auditory cortex of the behaving ferret are reviewed in the context of current research on cortical plasticity. Ferrets were trained on spectral tasks, including tone detection and two-tone discrimination, and on temporal tasks, including gap detection and click-rate discrimination. STRF changes could be measured on-line during task performance and occurred within minutes of task onset. During spectral tasks, there were specific spectral changes (enhanced response to tonal target frequency in tone detection and discrimination, suppressed response to tonal reference frequency in tone discrimination). However, only in the temporal tasks, the STRF was changed along the temporal dimension by sharpening temporal dynamics. In ferrets trained on multiple tasks, distinctive and task-specific STRF changes could be observed in the same cortical neurons in successive behavioral sessions. These results suggest that rapid task-related plasticity is an ongoing process that occurs at a network and single unit level as the animal switches between different tasks and dynamically adapts cortical STRFs in response to changing acoustic demands.

Connecting Lines of Research on Task Model Variables, Automatic Item Generation, and Learning Progressions in Game-Based Assessment

Science.gov (United States)

Graf, Edith Aurora

2014-01-01

In "How Task Features Impact Evidence from Assessments Embedded in Simulations and Games," Almond, Kim, Velasquez, and Shute have prepared a thought-provoking piece contrasting the roles of task model variables in a traditional assessment of mathematics word problems to their roles in "Newton's Playground," a game designed…

Children's On-Line Processing of Scrambling in Japanese

Science.gov (United States)

Suzuki, Takaaki

2013-01-01

This study investigates the on-line processing of scrambled sentences in Japanese by preschool children and adults using a combination of self-paced listening and speeded picture selection tasks. The effects of a filler-gap dependency, reversibility, and case markers were examined. The results show that both children and adults had difficulty in…

Implementing Information Security and Its Technology: A LineManagement Perspective

Energy Technology Data Exchange (ETDEWEB)

Barletta, William A.

2005-08-22

Assuring the security and privacy of institutionalinformation assets is a complex task for the line manager responsible forinternational and multi-national transactions. In the face of an unsureand often conflicting international legal framework, the line managermust employ all available tools in an Integrated Security and PrivacyManagement framework that ranges from legal obligations, to policy, toprocedure, to cutting edge technology to counter the rapidly evolvingcyber threat to information assets and the physical systems thatinformation systems control.

Number Line Estimation in Children with Developmental Dyscalculia

Science.gov (United States)

Sella, Francesco; Berteletti, Ilaria; Martina, Brazzolotto; Lucangeli, Daniela; Zorzi, Marco

2013-01-01

In the number to position task, several studies have shown that typically developing children shift from a biased (logarithmic) to an accurate (linear) mapping of symbolic digits onto a spatial position on a line. The initial pattern of overestimation of small numbers and the underestimation of larger numbers is compensated by means of age and…

On-line monitoring for calibration reduction

International Nuclear Information System (INIS)

Hoffmann, Mario; Gran, Frauke Schmitt; Thunem, Harald P-J.

2004-04-01

On-Line Monitoring (OLM) of a channel's calibration state evaluates instrument channel performance by assessing its consistency with other plant indications. Industry and experience at several plants has shown this overall approach to be very effective in identifying instrument channels that are exhibiting degrading or inconsistent performance characteristics. The Halden Reactor Project has developed the signal validation system PEANO, which can be used to assist with the tasks of OLM. To further enhance the PEANO System for use as a calibration reduction tool, the following two additional modules have been developed; HRP Prox, which performs pre-processing and statistical analysis of signal data, Batch Monitoring Module (BMM), which is an off-line batch monitoring and reporting suite. The purpose and functionality of the HRP Prox and BMM modules are discussed in this report, as well as the improvements made to the PEANO Server to support these new modules. The Halden Reactor Project has established a Halden On-Line Monitoring User Group (HOLMUG), devoted to the discussion and implementation of on-line monitoring techniques in power plants. It is formed by utilities, vendors, regulatory bodies and research institutes that meet regularly to discuss implementation aspects of on-line monitoring, technical specification changes, cost-benefit analysis and regulatory issues. (Author)

The line copy task for kinesthesia and internal movement representation: application in children.

NARCIS (Netherlands)

Smits-Engelsman, B.C.M.; Duysens, J.E.J.

2008-01-01

In the present study a new test is proposed and tested, which requires ability to use information both from kinesthesia and from mental rotation of previously produced cyclic movements over a distinct trajectory. This Line Copy Test (LICT) was performed by 58 children aged 7-11 years. For the

Information seeking research needs extension towards tasks and technology

Directory of Open Access Journals (Sweden)

Kalervo Järvelin

2004-01-01

Full Text Available This paper discusses the research into information seeking and its directions at a general level. We approach this topic by analysis and argumentation based on past research in the domain. We begin by presenting a general model of information seeking and retrieval (IS&R which is used to derive nine broad dimensions that are needed to analyze IS&R. Past research is then contrasted with the dimensions and shown not to cover the dimensions sufficiently. Based on an analysis of the goals of information seeking research, and a view on human task performance augmentation, it is then shown that information seeking is intimately associated with, and dependent on, other aspects of work; tasks and technology included. This leads to a discussion on design and evaluation frameworks for IS&R, based on which two action lines are proposed: information retrieval research needs extension towards more context and information seeking research needs extension towards tasks and technology.

Effects of noise and task loading on a communication task loading on a communication task

Science.gov (United States)

Orrell, Dean H., II

Previous research had shown the effect of noise on a single communication task. This research has been criticized as not being representative of a real world situation since subjects allocated all of their attention to only one task. In the present study, the effect of adding a loading task to a standard noise-communication paradigm was investigated. Subjects performed both a communication task (Modified Rhyme Test; House et al. 1965) and a short term memory task (Sternberg, 1969) in simulated levels of aircraft noise (95, 105 and 115 dB overall sound pressure level (OASPL)). Task loading was varied with Sternberg's task by requiring subjects to memorize one, four, or six alphanumeric characters. Simulated aircraft noise was varied between levels of 95, 105 and 115 dB OASPL using a pink noise source. Results show that the addition of Sternberg's task and little effect on the intelligibility of the communication task while response time for the communication task increased.

Who multi-tasks and why? Multi-tasking ability, perceived multi-tasking ability, impulsivity, and sensation seeking.

Science.gov (United States)

Sanbonmatsu, David M; Strayer, David L; Medeiros-Ward, Nathan; Watson, Jason M

2013-01-01

The present study examined the relationship between personality and individual differences in multi-tasking ability. Participants enrolled at the University of Utah completed measures of multi-tasking activity, perceived multi-tasking ability, impulsivity, and sensation seeking. In addition, they performed the Operation Span in order to assess their executive control and actual multi-tasking ability. The findings indicate that the persons who are most capable of multi-tasking effectively are not the persons who are most likely to engage in multiple tasks simultaneously. To the contrary, multi-tasking activity as measured by the Media Multitasking Inventory and self-reported cell phone usage while driving were negatively correlated with actual multi-tasking ability. Multi-tasking was positively correlated with participants' perceived ability to multi-task ability which was found to be significantly inflated. Participants with a strong approach orientation and a weak avoidance orientation--high levels of impulsivity and sensation seeking--reported greater multi-tasking behavior. Finally, the findings suggest that people often engage in multi-tasking because they are less able to block out distractions and focus on a singular task. Participants with less executive control--low scorers on the Operation Span task and persons high in impulsivity--tended to report higher levels of multi-tasking activity.

Who multi-tasks and why? Multi-tasking ability, perceived multi-tasking ability, impulsivity, and sensation seeking.

Directory of Open Access Journals (Sweden)

David M Sanbonmatsu

Full Text Available The present study examined the relationship between personality and individual differences in multi-tasking ability. Participants enrolled at the University of Utah completed measures of multi-tasking activity, perceived multi-tasking ability, impulsivity, and sensation seeking. In addition, they performed the Operation Span in order to assess their executive control and actual multi-tasking ability. The findings indicate that the persons who are most capable of multi-tasking effectively are not the persons who are most likely to engage in multiple tasks simultaneously. To the contrary, multi-tasking activity as measured by the Media Multitasking Inventory and self-reported cell phone usage while driving were negatively correlated with actual multi-tasking ability. Multi-tasking was positively correlated with participants' perceived ability to multi-task ability which was found to be significantly inflated. Participants with a strong approach orientation and a weak avoidance orientation--high levels of impulsivity and sensation seeking--reported greater multi-tasking behavior. Finally, the findings suggest that people often engage in multi-tasking because they are less able to block out distractions and focus on a singular task. Participants with less executive control--low scorers on the Operation Span task and persons high in impulsivity--tended to report higher levels of multi-tasking activity.

Who Multi-Tasks and Why? Multi-Tasking Ability, Perceived Multi-Tasking Ability, Impulsivity, and Sensation Seeking

Science.gov (United States)

Sanbonmatsu, David M.; Strayer, David L.; Medeiros-Ward, Nathan; Watson, Jason M.

2013-01-01

The present study examined the relationship between personality and individual differences in multi-tasking ability. Participants enrolled at the University of Utah completed measures of multi-tasking activity, perceived multi-tasking ability, impulsivity, and sensation seeking. In addition, they performed the Operation Span in order to assess their executive control and actual multi-tasking ability. The findings indicate that the persons who are most capable of multi-tasking effectively are not the persons who are most likely to engage in multiple tasks simultaneously. To the contrary, multi-tasking activity as measured by the Media Multitasking Inventory and self-reported cell phone usage while driving were negatively correlated with actual multi-tasking ability. Multi-tasking was positively correlated with participants’ perceived ability to multi-task ability which was found to be significantly inflated. Participants with a strong approach orientation and a weak avoidance orientation – high levels of impulsivity and sensation seeking – reported greater multi-tasking behavior. Finally, the findings suggest that people often engage in multi-tasking because they are less able to block out distractions and focus on a singular task. Participants with less executive control - low scorers on the Operation Span task and persons high in impulsivity - tended to report higher levels of multi-tasking activity. PMID:23372720

Task demand, task management, and teamwork

Energy Technology Data Exchange (ETDEWEB)

Braarud, Per Oeivind; Brendryen, Haavar

2001-03-15

The current approach to mental workload assessment in process control was evaluated in 3 previous HAMMLAB studies, by analysing the relationship between workload related measures and performance. The results showed that subjective task complexity rating was related to team's control room performance, that mental effort (NASA-TLX) was weakly related to performance, and that overall activity level was unrelated to performance. The results support the argument that general cognitive measures, i.e., mental workload, are weakly related to performance in the process control domain. This implies that other workload concepts than general mental workload are needed for valid assessment of human reliability and for valid assessment of control room configurations. An assessment of task load in process control suggested that how effort is used to handle task demand is more important then the level of effort invested to solve the task. The report suggests two main workload related concepts with a potential as performance predictors in process control: task requirements, and the work style describing how effort is invested to solve the task. The task requirements are seen as composed of individual task demand and team demand. In a similar way work style are seen as composed of individual task management and teamwork style. A framework for the development of the concepts is suggested based on a literature review and experiences from HAMMLAB research. It is suggested that operational definitions of workload concepts should be based on observable control room behaviour, to assure a potential for developing performance-shaping factors. Finally an explorative analysis of teamwork measures and performance in one study indicated that teamwork concepts are related to performance. This lends support to the suggested development of team demand and teamwork style as elements of a framework for the analysis of workload in process control. (Author)

Temporal Processing of Joyful and Disgusting Food Pictures by Women With an Eating Disorder

Science.gov (United States)

Gagnon, Caroline; Bégin, Catherine; Laflamme, Vincent; Grondin, Simon

2018-01-01

The present study used the presentation of food pictures and judgements about their duration to assess the emotions elicited by food in women suffering from an eating disorder (ED). Twenty-three women diagnosed with an ED, namely anorexia (AN) or bulimia nervosa (BN), and 23 healthy controls (HC) completed a temporal bisection task and a duration discrimination task. Intervals were marked with emotionally pre-rated pictures of joyful and disgusting food, and pictures of neutral objects. The results showed that, in the bisection task, AN women overestimated the duration of food pictures in comparison to neutral ones. Also, compared to participants with BN, they perceived the duration of joyful food pictures as longer, and tended to overestimate the duration of the disgusting ones. These effects on perceived duration suggest that AN women experienced an intense reaction of fear when they were confronted to food pictures. More precisely, by having elevated the arousal level and activated the defensive system, food pictures seemed to have speeded up the rhythm of the AN participants’ internal clock, which led to an overestimation of images’ duration. In addition, the results revealed that, in both tasks, ED women presented a lower temporal sensitivity than HC, which was related to their ED symptomatology (i.e., BMI, restraint and concern) and, particularly, to their weaker cognitive abilities in terms of attention, processing speed and working memory. Considered all together, the findings of the present experiment highlight the role of fear and anxiety in the manifestations of AN and point out the importance of considering non-temporal factors in the interpretation of time perception performance. PMID:29681806

Temporal Processing of Joyful and Disgusting Food Pictures by Women With an Eating Disorder.

Science.gov (United States)

Gagnon, Caroline; Bégin, Catherine; Laflamme, Vincent; Grondin, Simon

2018-01-01

The present study used the presentation of food pictures and judgements about their duration to assess the emotions elicited by food in women suffering from an eating disorder (ED). Twenty-three women diagnosed with an ED, namely anorexia (AN) or bulimia nervosa (BN), and 23 healthy controls (HC) completed a temporal bisection task and a duration discrimination task. Intervals were marked with emotionally pre-rated pictures of joyful and disgusting food, and pictures of neutral objects. The results showed that, in the bisection task, AN women overestimated the duration of food pictures in comparison to neutral ones. Also, compared to participants with BN, they perceived the duration of joyful food pictures as longer, and tended to overestimate the duration of the disgusting ones. These effects on perceived duration suggest that AN women experienced an intense reaction of fear when they were confronted to food pictures. More precisely, by having elevated the arousal level and activated the defensive system, food pictures seemed to have speeded up the rhythm of the AN participants' internal clock, which led to an overestimation of images' duration. In addition, the results revealed that, in both tasks, ED women presented a lower temporal sensitivity than HC, which was related to their ED symptomatology (i.e., BMI, restraint and concern) and, particularly, to their weaker cognitive abilities in terms of attention, processing speed and working memory. Considered all together, the findings of the present experiment highlight the role of fear and anxiety in the manifestations of AN and point out the importance of considering non-temporal factors in the interpretation of time perception performance.

Temporal Processing of Joyful and Disgusting Food Pictures by Women With an Eating Disorder

Directory of Open Access Journals (Sweden)

Caroline Gagnon

2018-04-01

Full Text Available The present study used the presentation of food pictures and judgements about their duration to assess the emotions elicited by food in women suffering from an eating disorder (ED. Twenty-three women diagnosed with an ED, namely anorexia (AN or bulimia nervosa (BN, and 23 healthy controls (HC completed a temporal bisection task and a duration discrimination task. Intervals were marked with emotionally pre-rated pictures of joyful and disgusting food, and pictures of neutral objects. The results showed that, in the bisection task, AN women overestimated the duration of food pictures in comparison to neutral ones. Also, compared to participants with BN, they perceived the duration of joyful food pictures as longer, and tended to overestimate the duration of the disgusting ones. These effects on perceived duration suggest that AN women experienced an intense reaction of fear when they were confronted to food pictures. More precisely, by having elevated the arousal level and activated the defensive system, food pictures seemed to have speeded up the rhythm of the AN participants’ internal clock, which led to an overestimation of images’ duration. In addition, the results revealed that, in both tasks, ED women presented a lower temporal sensitivity than HC, which was related to their ED symptomatology (i.e., BMI, restraint and concern and, particularly, to their weaker cognitive abilities in terms of attention, processing speed and working memory. Considered all together, the findings of the present experiment highlight the role of fear and anxiety in the manifestations of AN and point out the importance of considering non-temporal factors in the interpretation of time perception performance.

Can a virtual reality assessment of fine motor skill predict successful central line insertion?

Science.gov (United States)

Mohamadipanah, Hossein; Parthiban, Chembian; Nathwani, Jay; Rutherford, Drew; DiMarco, Shannon; Pugh, Carla

2016-10-01

Due to the increased use of peripherally inserted central catheter lines, central lines are not performed as frequently. The aim of this study is to evaluate whether a virtual reality (VR)-based assessment of fine motor skills can be used as a valid and objective assessment of central line skills. Surgical residents (N = 43) from 7 general surgery programs performed a subclavian central line in a simulated setting. Then, they participated in a force discrimination task in a VR environment. Hand movements from the subclavian central line simulation were tracked by electromagnetic sensors. Gross movements as monitored by the electromagnetic sensors were compared with the fine motor metrics calculated from the force discrimination tasks in the VR environment. Long periods of inactivity (idle time) during needle insertion and lack of smooth movements, as detected by the electromagnetic sensors, showed a significant correlation with poor force discrimination in the VR environment. Also, long periods of needle insertion time correlated to the poor performance in force discrimination in the VR environment. This study shows that force discrimination in a defined VR environment correlates to needle insertion time, idle time, and hand smoothness when performing subclavian central line placement. Fine motor force discrimination may serve as a valid and objective assessment of the skills required for successful needle insertion when placing central lines. Copyright © 2016 Elsevier Inc. All rights reserved.

Harmony Search for Balancing Two-sided Assembly Lines

Directory of Open Access Journals (Sweden)

Hindriyanto Dwi Purnomo

2012-01-01

Full Text Available Two-sided assembly lines balancing problems are important problem for large-sized products such as cars and buses, in which, tasks operations can be performed in the two sides of the line. In this paper, Harmony Search algorithm is proposed to solve two-sided assembly lines balancing problems type-I (TALBP-I. The proposed method adopts the COMSOAL heuristic and specific features of TALBP in the Harmony operators – the harmony memory consideration, random selection and pitch adjustment – in order to maintain the local and global search. The proposed method is evaluated based on 6 benchmark problems that are commonly used in TALBP. The experiment results show that the proposed method work well and produces better solution than the heuristic method and genetic algorithm.

Too easy? The influence of task demands conveyed tacitly on prospective memory

Science.gov (United States)

Lourenço, Joana S.; Hill, Johnathan H.; Maylor, Elizabeth A.

2015-01-01

Previous research suggests that when intentions are encoded, participants establish an attention allocation policy based on their metacognitive beliefs about how demanding it will be to fulfill the prospective memory (PM) task. We investigated whether tacit PM demands can influence judgments about the cognitive effort required for success, and, as a result, affect ongoing task interference and PM performance. Participants performed a lexical decision task in which a PM task of responding to animal words was embedded. PM demands were tacitly manipulated by presenting participants with either typical or atypical animal exemplars at both instructions and practice (low vs. high tacit demands, respectively). Crucially, objective PM task demands were the same for all participants as PM targets were always atypical animals. Tacit demands affected participants’ attention allocation policies such that task interference was greater for the high than low demands condition. Also, PM performance was reduced in the low relative to the high demands condition. Participants in the low demands condition who succeeded to the first target showed a subsequent increase in task interference, suggesting adjustment to the higher than expected demands. This study demonstrates that tacit information regarding the PM task can affect ongoing task processing as well as harm PM performance when actual demands are higher than expected. Furthermore, in line with the proposal that attention allocation is a dynamic and flexible process, we found evidence that PM task experience can trigger changes in ongoing task interference. PMID:25983687

Investigating the Effects of Concurrent Performance of Physical and Cognitive Demanding Task in Paced Assembly Lines

Directory of Open Access Journals (Sweden)

Shakil Ahmed Shaikh

2013-07-01

Full Text Available The study was undertaken to investigate the effects of pacing on aspects of performance at an assembly task and on the operators' responses related to work behaviour, perceived workload and perceived stress. A particular objective of the study was to investigate whether physical and cognitive demands may interact in their influences on these effects. An assembly task was simulated in the laboratory and the level of pacing imposed, work height and memory load within the task were all varied. The results showed that the type of pacing commonly imposed (as is common with a lean manufacturing Takt time system in industry can significantly affect both performance and perceived workload and stress. Physical demands (through work height affecting posture and mental demand (through memory load were also found to have significant effects, as would be expected from the many studies of these in the literature. More importantly, some interactions were found between pacing and work height in their effects on quality of assembly and the operator's own rating of performance, and between work height and memory load in their effects on errors. These findings will need to be taken into account by companies when implementing Takt time systems.

Extended 3D Line Segments from RGB-D Data for Pose Estimation

DEFF Research Database (Denmark)

Buch, Anders Glent; Jessen, Jeppe Barsøe; Kraft, Dirk

2013-01-01

We propose a method for the extraction of complete and rich symbolic line segments in 3D based on RGB-D data. Edges are detected by combining cues from the RGB image and the aligned depth map. 3D line segments are then reconstructed by back-projecting 2D line segments and intersecting this with l...... this with local surface patches computed from the 3D point cloud. Different edge types are classified using the new enriched representation and the potential of this representation for the task of pose estimation is demonstrated....

Age-related reduction of hemispheric lateralisation for spatial attention: An EEG study.

Science.gov (United States)

Learmonth, Gemma; Benwell, Christopher S Y; Thut, Gregor; Harvey, Monika

2017-06-01

A group-level visuospatial attention bias towards the left side of space (pseudoneglect) is consistently observed in young adults, which is likely to be a consequence of right parieto-occipital dominance for spatial attention. Conversely, healthy older adults demonstrate a rightward shift of this behavioural bias, hinting that an age-related reduction of lateralised neural activity may occur within visuospatial attention networks. We compared young (aged 18-25) and older (aged 60-80) adults on a computerised line bisection (landmark) task whilst recording event-related potentials (ERPs). Full-scalp cluster mass permutation tests identified a larger right parieto-occipital response for long lines compared to short in young adults (confirming Benwell et al., 2014a) which was not present in the older group. To specifically investigate age-related differences in hemispheric lateralisation, cluster mass permutation tests were then performed on a lateralised EEG dataset (RH-LH electrodes). A period of right lateralisation was identified in response to long lines in young adults, which was not present for short lines. No lateralised clusters were present for either long or short lines in older adults. Additionally, a reduced P300 component amplitude was observed for older adults relative to young. We therefore report here, for the first time, an age-related and stimulus-driven reduction of right hemispheric control of spatial attention in older adults. Future studies will need to determine whether this is representative of the normal aging process or an early indicator of neurodegeneration. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Improvement and validation of isotopic libraries of commercial gamma spectra evaluation packages. Report on task FIN A 955 of Finnish support programme to IAEA safeguards

Energy Technology Data Exchange (ETDEWEB)

Nikkinen, M.

1997-06-01

The Department of Safeguards at the International Atomic Energy Agency (IAEA) is running gamma spectroscopy analysis with various samples taken at various stages of the nuclear fuel cycle. It was found that the commercial gamma spectra analysis packages available do not include proper gamma-line libraries for the various tasks needed for the safeguards purposes because the libraries of these packages are often incomplete and outdated. New libraries were developed to satisfy the needs in the analysis tasks required for the safeguards purposes. These lines are limited by the number of gamma lines to avoid the problems with too many candidates for a single gamma peak. The work was carried out under the Task FIN A 955 Finnish Support Programme to IAEA Safeguards. (orig.) (18 refs.).

Task analysis and support for problem solving tasks

International Nuclear Information System (INIS)

Bainbridge, L.

1987-01-01

This paper is concerned with Task Analysis as the basis for ergonomic design to reduce human error rates, rather than for predicting human error rates. Task Analysis techniques usually provide a set of categories for describing sub tasks, and a framework describing the relations between sub-tasks. Both the task type categories and their organisation have implications for optimum interface and training design. In this paper, the framework needed for considering the most complex tasks faced by operators in process industries is discussed such as fault management in unexpected situations, and what is likely to minimise human error in these circumstances. (author)

Background matters: Minor vibratory stimulation during motor skill acquisition selectively reduces off-line memory consolidation.

Science.gov (United States)

Korman, Maria; Herling, Zohar; Levy, Ishay; Egbarieh, Nebal; Engel-Yeger, Batya; Karni, Avi

2017-04-01

Although a ubiquitous situation, it is not clear how effective is a learning experience when task-irrelevant, sensory noise occurs in the background. Here, young adults were trained on the finger opposition sequence task, in a well-established training and testing protocol affording measures for online as well as off-line learning. During the training session, one group experienced a minor background vibratory stimulation to the trunk by the means of vibrating cushion, while the second group experienced recorded sound vibrations. A control group was trained with no extra sensory stimulation. Sensory stimulation during training had no effect on the online within-session gains, but dampened the expression of the off-line, consolidation phase, gains in the two sensory stimulation groups. These results suggest that background sensory stimulation can selectively modify off-line, procedural memory consolidation processes, despite well-preserved on-line learning. Classical studies have shown that neural plasticity in sensory systems is modulated by motor input. The current results extend this notion and suggest that some types of task-irrelevant sensory stimulation, concurrent with motor training, may constitute a 'gating' factor - modulating the triggering of long-term procedural memory consolidation processes. Thus, vibratory stimulation may be considered as a behavioral counterpart of pharmacological interventions that do not interfere with short term neural plasticity but block long-term plasticity. Copyright © 2017 Elsevier Inc. All rights reserved.

Embodied simulation as part of affective evaluation processes: task dependence of valence concordant EMG activity.

Science.gov (United States)

Weinreich, André; Funcke, Jakob Maria

2014-01-01

Drawing on recent findings, this study examines whether valence concordant electromyography (EMG) responses can be explained as an unconditional effect of mere stimulus processing or as somatosensory simulation driven by task-dependent processing strategies. While facial EMG over the Corrugator supercilii and the Zygomaticus major was measured, each participant performed two tasks with pictures of album covers. One task was an affective evaluation task and the other was to attribute the album covers to one of five decades. The Embodied Emotion Account predicts that valence concordant EMG is more likely to occur if the task necessitates a somatosensory simulation of the evaluative meaning of stimuli. Results support this prediction with regard to Corrugator supercilii in that valence concordant EMG activity was only present in the affective evaluation task but not in the non-evaluative task. Results for the Zygomaticus major were ambiguous. Our findings are in line with the view that EMG activity is an embodied part of the evaluation process and not a mere physical outcome.

Sleep parameters, functional status and time post-stroke are associated with off-line motor skill learning in people with chronic stroke

Directory of Open Access Journals (Sweden)

Catherine eSiengsukon

2015-10-01

Full Text Available Background: Mounting evidence demonstrates that individuals with stroke benefit from sleep to enhance learning of a motor task. While stage NREM2 sleep and REM sleep have been associated with off-line motor skill learning in neurologically-intact individuals, it remains unknown which sleep parameters or specific sleep stages are associated with off-line motor skill learning in individuals with stroke. Methods: Twenty individuals with chronic stroke (> 6 months following stroke and 10 neurologically slept for three consecutive nights in a sleep laboratory with polysomnography. Participants practiced a tracking task the morning before the third night and underwent a retention test the morning following the third night. Off-line learning on the tracking task was assessed. Pearson’s correlations assessed for associations between the magnitude of off-line learning and sleep variables, age, upper extremity motor function, stroke severity, depression and time since stroke occurrence.Results: Individuals with stroke performed with significantly less error on the tracking task following a night of sleep (p=.006 while the control participants did not (p=.816. Increased sleep efficiency (r= -.285, less time spent in stage NREM3 sleep (r=.260, and more time spent in stage REM sleep (r= -.266 was weakly-to-moderately associated with increased magnitude of off-line motor learning. Furthermore, higher upper-extremity motor function (r = -.400, lower stroke severity (r = .360, and less time since stroke occurrence (r=.311 were moderately associated with increased magnitude of off-line motor learning. Conclusion: This study is the first study to provide insight into which sleep stages and individual characteristics may be associated with off-line learning in people with stroke. Future work should continue to understand which factors or combination of factors promote off-line motor learning in people with neurologic injury to best promote motor recovery in

Generic cognitive adaptations to task interference in task switching

NARCIS (Netherlands)

Poljac, E.; Bekkering, H.

2009-01-01

The present study investigated how the activation of previous tasks interferes with the execution of future tasks as a result of temporal manipulations. Color and shape matching tasks were organized in runs of two trials each. The tasks were specified by a cue presented before a task run, cueing

Can free-viewing perceptual asymmetries be explained by scanning, pre-motor or attentional biases?

Science.gov (United States)

Nicholls, Michael E R; Roberts, Georgina R

2002-04-01

Judgments of relative magnitude between the left and right sides of a stimulus are generally weighted toward the features contained on the left side. This leftward perceptual bias could be the result of, (a) left-to-right scanning biases, (b) pre-motor activation of the right hemisphere, or (c) a left hemispatial attentional bias. The relative merits of these explanations of perceptual asymmetry were investigated. In Experiment 1, English and Hebrew readers made luminance judgements for two left/right mirror-reversed luminance gradients (greyscales task). Despite different reading/scanning habits, both groups exhibited a leftward perceptual bias. English and Hebrew readers also performed a line bisection task. Scanning biases were controlled by asking participants to follow a marker as it moved left-to-right or right-to-left and then stop it as it reached the midpoint of the line. Despite controlling scanning, a leftward bias was observed in both groups. In Experiment 2, peripheral spatial cues were presented prior to the greyscales stimuli. English readers showed a reduction in the leftward bias for right-sided cues as compared to left-sided and neutral cues. Right-side cues presumably overcame a pre-existing leftward attentional bias. In both experiments, pre-motor activation was controlled using bimanual responses. Despite this control, a leftward bias was observed throughout the study. The data support the attentional bias account of leftward perceptual biases over the scanning and pre-motor activation accounts. Whether or not unilateral hemispheric activation provides an adequate account of this attentional bias is discussed.

Performance analysis of flow lines with non-linear flow of material

CERN Document Server

Helber, Stefan

1999-01-01

Flow line design is one of the major tasks in production management. The decision to install a set of machines and buffers is often highly irreversible. It determines both cost and revenue to a large extent. In order to assess the economic impact of any possible flow line design, production rates and inventory levels have to be estimated. These performance measures depend on the allocation of buffers whenever the flow of material is occasionally disrupted, for example due to machine failures or quality problems. The book describes analytical methods that can be used to evaluate flow lines much faster than with simulation techniques. Based on these fast analytical techniques, it is possible to determine a flow line design that maximizes the net present value of the flow line investment. The flow of material through the line may be non-linear, for example due to assembly operations or quality inspections.

Working Memory Training Improves Dual-Task Performance on Motor Tasks.

Science.gov (United States)

Kimura, Takehide; Kaneko, Fuminari; Nagahata, Keita; Shibata, Eriko; Aoki, Nobuhiro

2017-01-01

The authors investigated whether working memory training improves motor-motor dual-task performance consisted of upper and lower limb tasks. The upper limb task was a simple reaction task and the lower limb task was an isometric knee extension task. 45 participants (age = 21.8 ± 1.6 years) were classified into a working memory training group (WM-TRG), dual-task training group, or control group. The training duration was 2 weeks (15 min, 4 times/week). Our results indicated that working memory capacity increased significantly only in the WM-TRG. Dual-task performance improved in the WM-TRG and dual-task training group. Our study provides the novel insight that working memory training improves dual-task performance without specific training on the target motor task.

Music-induced changes in functional cerebral asymmetries.

Science.gov (United States)

Hausmann, Markus; Hodgetts, Sophie; Eerola, Tuomas

2016-04-01

After decades of research, it remains unclear whether emotion lateralization occurs because one hemisphere is dominant for processing the emotional content of the stimuli, or whether emotional stimuli activate lateralised networks associated with the subjective emotional experience. By using emotion-induction procedures, we investigated the effect of listening to happy and sad music on three well-established lateralization tasks. In a prestudy, Mozart's piano sonata (K. 448) and Beethoven's Moonlight Sonata were rated as the most happy and sad excerpts, respectively. Participants listened to either one emotional excerpt, or sat in silence before completing an emotional chimeric faces task (Experiment 1), visual line bisection task (Experiment 2) and a dichotic listening task (Experiment 3 and 4). Listening to happy music resulted in a reduced right hemispheric bias in facial emotion recognition (Experiment 1) and visuospatial attention (Experiment 2) and increased left hemispheric bias in language lateralization (Experiments 3 and 4). Although Experiments 1-3 revealed an increased positive emotional state after listening to happy music, mediation analyses revealed that the effect on hemispheric asymmetries was not mediated by music-induced emotional changes. The direct effect of music listening on lateralization was investigated in Experiment 4 in which tempo of the happy excerpt was manipulated by controlling for other acoustic features. However, the results of Experiment 4 made it rather unlikely that tempo is the critical cue accounting for the effects. We conclude that listening to music can affect functional cerebral asymmetries in well-established emotional and cognitive laterality tasks, independent of music-induced changes in the emotion state. Copyright © 2016 Elsevier Inc. All rights reserved.

Task-based exposure assessment of nanoparticles in the workplace

International Nuclear Information System (INIS)

Ham, Seunghon; Yoon, Chungsik; Lee, Euiseung; Lee, Kiyoung; Park, Donguk; Chung, Eunkyo; Kim, Pilje; Lee, Byoungcheun

2012-01-01

Although task-based sampling is, theoretically, a plausible approach to the assessment of nanoparticle exposure, few studies using this type of sampling have been published. This study characterized and compared task-based nanoparticle exposure profiles for engineered nanoparticle manufacturing workplaces (ENMW) and workplaces that generated welding fumes containing incidental nanoparticles. Two ENMW and two welding workplaces were selected for exposure assessments. Real-time devices were utilized to characterize the concentration profiles and size distributions of airborne nanoparticles. Filter-based sampling was performed to measure time-weighted average (TWA) concentrations, and off-line analysis was performed using an electron microscope. Workplace tasks were recorded by researchers to determine the concentration profiles associated with particular tasks/events. This study demonstrated that exposure profiles differ greatly in terms of concentrations and size distributions according to the task performed. The size distributions recorded during tasks were different from both those recorded during periods with no activity and from the background. The airborne concentration profiles of the nanoparticles varied according to not only the type of workplace but also the concentration metrics. The concentrations measured by surface area and the number concentrations measured by condensation particle counter, particulate matter 1.0, and TWA mass concentrations all showed a similar pattern, whereas the number concentrations measured by scanning mobility particle sizer indicated that the welding fume concentrations at one of the welding workplaces were unexpectedly higher than were those at workplaces that were engineering nanoparticles. This study suggests that a task-based exposure assessment can provide useful information regarding the exposure profiles of nanoparticles and can therefore be used as an exposure assessment tool.

Stress at School? A Qualitative Study on Illegitimate Tasks during Teacher Training.

Science.gov (United States)

Faupel, Stefanie; Otto, Kathleen; Krug, Henning; Kottwitz, Maria U

2016-01-01

What do I expect when stating that "I am going to be a teacher"? Social roles, including professional roles, often become part of people's identity and thus, of the self. As people typically strive for maintaining a positive sense of self, threats to one's role identity are likely to induce stress. In line with these considerations, Semmer et al. recently (e.g., Semmer et al., 2007, 2015) introduced "illegitimate tasks" as a new concept of stressors. Illegitimate tasks, which are defined as unnecessary or unreasonable tasks, threaten the self because they signal a lack of appreciation regarding one's professional role. Teacher training is a phase of role transition in which the occurrence of illegitimate tasks becomes likely. A holistic understanding of these tasks, however, has been missing up to now. Is there already a professional role identity during teacher training that is vulnerable to threats like the illegitimacy of tasks? What are typical illegitimate tasks in the context of teacher training? In order to close this research gap, 39 situations taken from 16 interviews with teaching trainees were analyzed in the present study on the basis of qualitative content analysis. Seminars and standing in to hold lessons for other teachers were identified as most prevalent illegitimate tasks. More specifically, unnecessary tasks could be classified as sub challenging, inefficient and lacking in organization (e.g., writing reports about workshops no one will ever read). Unreasonable tasks appeared overextending, fell outside responsibility, and lacked supervisory support. Training interventions focusing upon task design and supervisory behavior are suggested for improvement.

Stress at school? A Qualitative Study on Illegitimate Tasks during Teacher Training

Directory of Open Access Journals (Sweden)

Stefanie Faupel

2016-09-01

Full Text Available What do I expect when stating that I am going to be a teacher? Social roles, including professional roles, often become part of people’s identity and thus, of the self. As people typically strive for maintaining a positive sense of self, threats to one’s role identity are likely to induce stress. In line with these considerations, Semmer et al. recently (e.g., 2007, 2015 introduced illegitimate tasks as a new concept of stressors. Illegitimate tasks, which are defined as unnecessary or unreasonable tasks, threaten the self because they signal a lack of appreciation regarding one’s professional role. Teacher training is a phase of role transition in which the occurrence of illegitimate tasks becomes likely. A holistic understanding of these tasks, however, has been missing up to now. Is there already a professional role identity during teacher training that is vulnerable to threats like the illegitimacy of tasks? What are typical illegitimate tasks in the context of teacher training? In order to close this research gap, 39 situations taken from 16 interviews with teaching trainees were analyzed in the present study on the basis of qualitative content analysis. Seminars and standing in to hold lessons for other teachers were identified as most prevalent illegitimate tasks. More specifically, unnecessary tasks could be classified as sub challenging, inefficient and lacking in organization (e.g., writing reports about workshops no one will ever read. Unreasonable tasks appeared overextending, fell outside responsibility, and lacked supervisory support. Training interventions focusing upon task design and supervisory behavior are suggested for improvement.

PhenoLines: Phenotype Comparison Visualizations for Disease Subtyping via Topic Models.

Science.gov (United States)

Glueck, Michael; Naeini, Mahdi Pakdaman; Doshi-Velez, Finale; Chevalier, Fanny; Khan, Azam; Wigdor, Daniel; Brudno, Michael

2018-01-01

PhenoLines is a visual analysis tool for the interpretation of disease subtypes, derived from the application of topic models to clinical data. Topic models enable one to mine cross-sectional patient comorbidity data (e.g., electronic health records) and construct disease subtypes-each with its own temporally evolving prevalence and co-occurrence of phenotypes-without requiring aligned longitudinal phenotype data for all patients. However, the dimensionality of topic models makes interpretation challenging, and de facto analyses provide little intuition regarding phenotype relevance or phenotype interrelationships. PhenoLines enables one to compare phenotype prevalence within and across disease subtype topics, thus supporting subtype characterization, a task that involves identifying a proposed subtype's dominant phenotypes, ages of effect, and clinical validity. We contribute a data transformation workflow that employs the Human Phenotype Ontology to hierarchically organize phenotypes and aggregate the evolving probabilities produced by topic models. We introduce a novel measure of phenotype relevance that can be used to simplify the resulting topology. The design of PhenoLines was motivated by formative interviews with machine learning and clinical experts. We describe the collaborative design process, distill high-level tasks, and report on initial evaluations with machine learning experts and a medical domain expert. These results suggest that PhenoLines demonstrates promising approaches to support the characterization and optimization of topic models.

Exploratory Analysis of an On-line Evolutionary Algorithm in Simulated Robots

NARCIS (Netherlands)

Haasdijk, E.W.; Smit, S.K.; Eiben, A.E.

2012-01-01

In traditional evolutionary robotics, robot controllers are evolved in a separate design phase preceding actual deployment; we call this off-line evolution. Alternatively, robot controllers can evolve while the robots perform their proper tasks, during the actual operational phase; we call this

Task Switching in a Hierarchical Task Structure: Evidence for the Fragility of the Task Repetition Benefit

Science.gov (United States)

Lien, Mei-Ching; Ruthruff, Eric

2004-01-01

This study examined how task switching is affected by hierarchical task organization. Traditional task-switching studies, which use a constant temporal and spatial distance between each task element (defined as a stimulus requiring a response), promote a flat task structure. Using this approach, Experiment 1 revealed a large switch cost of 238 ms.…

The Influencing Factor Analysis on the Performance Evaluation of Assembly Line Balancing Problem Level 1 (SALBP-1) Based on ANOVA Method

Science.gov (United States)

Chen, Jie; Hu, Jiangnan

2017-06-01

Industry 4.0 and lean production has become the focus of manufacturing. A current issue is to analyse the performance of the assembly line balancing. This study focus on distinguishing the factors influencing the assembly line balancing. The one-way ANOVA method is applied to explore the significant degree of distinguished factors. And regression model is built to find key points. The maximal task time (tmax ), the quantity of tasks (n), and degree of convergence of precedence graph (conv) are critical for the performance of assembly line balancing. The conclusion will do a favor to the lean production in the manufacturing.

Task-driven image acquisition and reconstruction in cone-beam CT

International Nuclear Information System (INIS)

Gang, Grace J; Stayman, J Webster; Siewerdsen, Jeffrey H; Ehtiati, Tina

2015-01-01

This work introduces a task-driven imaging framework that incorporates a mathematical definition of the imaging task, a model of the imaging system, and a patient-specific anatomical model to prospectively design image acquisition and reconstruction techniques to optimize task performance. The framework is applied to joint optimization of tube current modulation, view-dependent reconstruction kernel, and orbital tilt in cone-beam CT. The system model considers a cone-beam CT system incorporating a flat-panel detector and 3D filtered backprojection and accurately describes the spatially varying noise and resolution over a wide range of imaging parameters in the presence of a realistic anatomical model. Task-based detectability index (d′) is incorporated as the objective function in a task-driven optimization of image acquisition and reconstruction techniques. The orbital tilt was optimized through an exhaustive search across tilt angles ranging ±30°. For each tilt angle, the view-dependent tube current and reconstruction kernel (i.e. the modulation profiles) that maximized detectability were identified via an alternating optimization. The task-driven approach was compared with conventional unmodulated and automatic exposure control (AEC) strategies for a variety of imaging tasks and anthropomorphic phantoms. The task-driven strategy outperformed the unmodulated and AEC cases for all tasks. For example, d′ for a sphere detection task in a head phantom was improved by 30% compared to the unmodulated case by using smoother kernels for noisy views and distributing mAs across less noisy views (at fixed total mAs) in a manner that was beneficial to task performance. Similarly for detection of a line-pair pattern, the task-driven approach increased d′ by 80% compared to no modulation by means of view-dependent mA and kernel selection that yields modulation transfer function and noise-power spectrum optimal to the task. Optimization of orbital tilt identified the

Differential preparation intervals modulate repetition processes in task switching: an ERP study

Directory of Open Access Journals (Sweden)

Min eWang

2016-02-01

Full Text Available In task-switching paradigms, reaction times (RTs switch cost (SC and the neural correlates underlying the SC are affected by different preparation intervals. However, little is known about the effect of the preparation interval on the repetition processes in task-switching. To examine this effect we utilized a cued task-switching paradigm with long sequences of repeated trials. Response-stimulus intervals (RSI and cue-stimulus intervals (CSI were manipulated in short and long conditions. Electroencephalography (EEG and behavioral data were recorded. We found that with increasing repetitions, RTs were faster in the short CSI conditions, while P3 amplitudes decreased in the LS (long RSI and short CSI conditions. Positive correlations between RT benefit and P3 activation decrease (repeat 1 minus repeat 5, and between the slope of the RT and P3 regression lines were observed only in the LS condition. Our findings suggest that differential preparation intervals modulate repetition processes in task switching.

Heuristic for Task-Worker Assignment with Varying Learning Slopes

Directory of Open Access Journals (Sweden)

Wipawee Tharmmaphornphilas

2010-04-01

Full Text Available Fashion industry has variety products, so the multi-skilled workers are required to improve flexibility in production and assignment. Generally the supervisor will assign task to the workers based on skill and skill levels of worker. Since in fashion industry new product styles are launched more frequently and the order size tends to be smaller, the workers always learn when the raw material and the production process changes. Consequently they require less time to produce the succeeding units of a task based on their learning ability. Since the workers have both experience and inexperience workers, so each worker has different skill level and learning ability. Consequently, the assignment which assumed constant skill level is not proper to use. This paper proposes a task-worker assignment considering worker skill levels and learning abilities. Processing time of each worker changes along production period due to a worker learning ability. We focus on a task-worker assignment in a fashion industry where tasks are ordered in series; the number of tasks is greater than the number of workers. Therefore, workers can perform multiple assignments followed the precedence restriction as an assembly line balancing problem. The problem is formulated in an integer linear programming model with objective to minimize makespan. A heuristic is proposed to determine the lower bound (LB and the upper bound (UB of the problem and the best assignment is determined. The performance of the heuristic method is tested by comparing quality of solution and computational time to optimal solutions.

The 2 mrad crossing-angle ILC interaction region and extraction line

CERN Document Server

Appleby, Robert; Bambade, Philip; Dadoun, Olivier; Parker, Brett; Keller, Lewis; Moffeit, Kenneth C; Nosochkov, Yuri; Seryi, Andrei; Spencer, Cherrill M; Carter, John; Napoly, Olivier

2006-01-01

A complete optics design for the 2mrad crossing angle interaction region and extraction line was presented at Snowmass 2005. Since this time, the design task force has been working on developing and improving the performance of the extraction line. The work has focused on optimising the final doublet parameters and on reducing the power losses resulting from the disrupted beam transport. In this paper, the most recent status of the 2mrad layout and the corresponding performance are presented.

Stride time synergy in relation to walking during dual task

DEFF Research Database (Denmark)

Læssøe, Uffe; Madeleine, Pascal

2012-01-01

point of view elemental and performance variables may represent good and bad components of variability [2]. In this study we propose that the gait pattern can be seen as an on-going movement synergy in which each stride is corrected by the next stride (elemental variables) to ensure a steady gait...... (performance variable). AIM: The aim of this study was to evaluate stride time synergy and to identify good and bad stride variability in relation to walking during dual task. METHODS: Thirteen healthy young participants walked along a 2x5 meter figure-of-eight track at a self-selected comfortable speed...... with a positive slope going through the mean of the strides, and bad variance with respect to a similar line with a negative slope. The general variance coefficient (CV%) was also computed. The effect of introducing a concurrent cognitive task (dual task: counting backwards in sequences of 7) was evaluated...

Aging changes 3D perception: Evidence for hemispheric rebalancing of lateralized processes.

Science.gov (United States)

Andrews, Bridget; d'Avossa, Giovanni; Sapir, Ayelet

2017-05-01

When judging the 3D shape of a shaded image, young observers assume that the light source is placed above and to the left. This leftward bias has been attributed to hemispheric lateralization or experiential factors. Since aging is associated with loss of hemispheric lateralization, in the current study we measured the effect of aging on the assumed light source direction. Older participants exhibited, on average, a decreased left bias compared to young participants, as well as greater within-group variability in the distribution of assumed light source directions. In a separate sample of young and old participants, we replicated the age related effect in the assumed light source direction. Furthermore, in both young and old participants the assumed light source direction and the lateralized bias in a line bisection task were correlated. These findings suggest that diminished hemispheric lateralization, which accompanies aging, may affect the perception of the 3D structure of shaded surfaces. Shape from shading may thus provide a simple behavioral tool to track age related changes in hemispheric organization. Copyright © 2017 Elsevier Ltd. All rights reserved.

Task-set inertia and memory-consolidation bottleneck in dual tasks.

Science.gov (United States)

Koch, Iring; Rumiati, Raffaella I

2006-11-01

Three dual-task experiments examined the influence of processing a briefly presented visual object for deferred verbal report on performance in an unrelated auditory-manual reaction time (RT) task. RT was increased at short stimulus-onset asynchronies (SOAs) relative to long SOAs, showing that memory consolidation processes can produce a functional processing bottleneck in dual-task performance. In addition, the experiments manipulated the spatial compatibility of the orientation of the visual object and the side of the speeded manual response. This cross-task compatibility produced relative RT benefits only when the instruction for the visual task emphasized overlap at the level of response codes across the task sets (Experiment 1). However, once the effective task set was in place, it continued to produce cross-task compatibility effects even in single-task situations ("ignore" trials in Experiment 2) and when instructions for the visual task did not explicitly require spatial coding of object orientation (Experiment 3). Taken together, the data suggest a considerable degree of task-set inertia in dual-task performance, which is also reinforced by finding costs of switching task sequences (e.g., AC --> BC vs. BC --> BC) in Experiment 3.

Effects of Dual-Task Management and Resistance Training on Gait Performance in Older Individuals: A Randomized Controlled Trial

Directory of Open Access Journals (Sweden)

Bettina Wollesen

2017-12-01

Full Text Available Background: Dual-task (DT training is a well-accepted modality for fall prevention in older adults. DT training should include task-managing strategies such as task switching or task prioritization to improve gait performance under DT conditions.Methods: We conducted a randomized controlled trial to evaluate a balance and task managing training (BDT group in gait performance compared to a single task (ST strength and resistance training and a control group, which received no training. A total of 78 older individuals (72.0 ± 4.9 years participated in this study. The DT group performed task managing training incorporating balance and coordination tasks while the ST group performed resistance training only. Training consisted of 12 weekly sessions, 60 min each, for 12 weeks. We assessed the effects of ST and BDT training on walking performance under ST and DT conditions in independent living elderly adults. ST and DT walking (visual verbal Stroop task were measured utilizing a treadmill at self-selected walking speed (mean for all groups: 4.4 ± 1 km h-1. Specific gait variables, cognitive performance, and fear of falling were compared between all groups.>Results: Training improved gait performance for step length (p < 0.001 and gait-line (ST: p < 0.01; DT p < 0.05 in both training groups. The BDT training group showed greater improvements in step length (p < 0.001 and gait-line (p < 0.01 during DT walking but did not have changes in cognitive performance. Both interventions reduced fear of falling (p < 0.05.Conclusion: Implementation of task management strategies into balance and strength training in our population revealed a promising modality to prevent falls in older individuals.Trial registration: German register of clinical trials DRKS00012382.

Glycan structures contain information for the spatial arrangement of glycoproteins in the plasma membrane.

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M Kristen Hall

Full Text Available Glycoconjugates at the cell surface are crucial for cells to communicate with each other and the extracellular microenvironment. While it is generally accepted that glycans are vectorial biopolymers, their information content is unclear. This report provides evidence that distinct N-glycan structures influence the spatial arrangement of two integral membrane glycoproteins, Kv3.1 and E-cadherin, at the adherent membrane which in turn alter cellular properties. Distinct N-glycan structures were generated by heterologous expression of these glycoproteins in parental and glycosylation mutant Chinese hamster ovary cell lines. Unlike the N-linked glycans, the O-linked glycans of the mutant cell lines are similar to those of the parental cell line. Western and lectin blots of total membranes and GFP immunopurified samples, combined with glycosidase digestion reactions, were employed to verify the glycoproteins had predominantly complex, oligomannose, and bisecting type N-glycans from Pro(-5, Lec1, and Lec10B cell lines, respectively. Based on total internal reflection fluorescence and differential interference contrast microscopy techniques, and cellular assays of live parental and glycosylation mutant CHO cells, we propose that glycoproteins with complex, oligomannose or bisecting type N-glycans relay information for localization of glycoproteins to various regions of the plasma membrane in both a glycan-specific and protein-specific manner, and furthermore cell-cell interactions are required for deciphering much of this information. These distinct spatial arrangements also impact cell adhesion and migration. Our findings provide direct evidence that N-glycan structures of glycoproteins contribute significantly to the information content of cells.

Frequency modulation system test procedure shuttle task 501 approach and landing test configuration

Science.gov (United States)

Doland, G. D.

1976-01-01

Shuttle Task 501 is an in-line task to test the performance and compatibility of radiofrequency links between the SSO and ground, and relay via a satellite. Under Shuttle Task 501 approach and landing test (ALT) phase only a limited portion of the communication and tracking (C&T) equipment is to be tested. The principal item to be tested is a frequency modulated (FM) data link. To test this RF link, an ALT FM System was designed, constructed, and the console wiring verified. A step-by-step procedure to be used to perform the ALT FM system is presented. The ALT FM system test is to be performed prior to delivery of the equipment to the Electronic Systems Test Laboratory (ESTL).

New percepts via mental imagery?

Directory of Open Access Journals (Sweden)

Fred Walter Mast

2012-10-01

Full Text Available We are able to extract detailed information from mental images that we were not explicitly aware of during encoding. For example, we can discover a new figure when we rotate a previously seen image in our mind. However, such discoveries are not really new but just new interpretations. In two recent publications, we have shown that mental imagery can lead to perceptual learning (Tartaglia et al., 2009, 2012. Observers imagined the central line of a bisection stimulus for thousands of trials. This training enabled observers to perceive bisection offsets that were invisible before training. Hence, it seems that perceptual learning via mental imagery leads to new percepts. We will argue, however, that these new percepts can occur only within known models. In this sense, perceptual learning via mental imagery exceeds new discoveries in mental images. Still, the effects of mental imagery on perceptual learning are limited. Only perception can lead to really new perceptual experience.

Who Multi-Tasks and Why? Multi-Tasking Ability, Perceived Multi-Tasking Ability, Impulsivity, and Sensation Seeking

OpenAIRE

Sanbonmatsu, David M.; Strayer, David L.; Medeiros-Ward, Nathan; Watson, Jason M.

2013-01-01

The present study examined the relationship between personality and individual differences in multi-tasking ability. Participants enrolled at the University of Utah completed measures of multi-tasking activity, perceived multi-tasking ability, impulsivity, and sensation seeking. In addition, they performed the Operation Span in order to assess their executive control and actual multi-tasking ability. The findings indicate that the persons who are most capable of multi-tasking effectively are ...

Investigating neural efficiency of elite karate athletes during a mental arithmetic task using EEG.

Science.gov (United States)

Duru, Adil Deniz; Assem, Moataz

2018-02-01

Neural efficiency is proposed as one of the neural mechanisms underlying elite athletic performances. Previous sports studies examined neural efficiency using tasks that involve motor functions. In this study we investigate the extent of neural efficiency beyond motor tasks by using a mental subtraction task. A group of elite karate athletes are compared to a matched group of non-athletes. Electroencephalogram is used to measure cognitive dynamics during resting and increased mental workload periods. Mainly posterior alpha band power of the karate players was found to be higher than control subjects under both tasks. Moreover, event related synchronization/desynchronization has been computed to investigate the neural efficiency hypothesis among subjects. Finally, this study is the first study to examine neural efficiency related to a cognitive task, not a motor task, in elite karate players using ERD/ERS analysis. The results suggest that the effect of neural efficiency in the brain is global rather than local and thus might be contributing to the elite athletic performances. Also the results are in line with the neural efficiency hypothesis tested for motor performance studies.

The Influence of Odors on Time Perception

OpenAIRE

Millot, Jean-Louis; Laurent, Lucie; Casini, Laurence

2016-01-01

International audience; The effect of an olfactory stimulation on the perception of time was investigated through two different experiments based on temporal bisection tasks. In experiment 1, the durations to be classified as either short or long were centered on 400 ms while in Experiment 2 there were centered on 2000 ms. The participants were different in the two experiments (36 subjects in each one). In each experiment, half of the subjects learnt the anchor durations when smelling an unpl...

Program elaborated of combined regime for on-line and off-line problems

International Nuclear Information System (INIS)

Ivanova, A.B.; Ioramashvili, Eh.Sh.; Polyakov, B.F.; Razdol'skaya, L.A.

1979-01-01

A description of the part of operational system designed for organization of packet treatment of algol tasks combined with the on-line system is provided. A block-scheme of the operational system functioning in the packet regime is presented. The ''Director'' program is the main part of the operational system which is responsible for the functioning of the algol programs. Its starting for the first time is carried out by the operator. All the subsequent process of the operation is automized. Problems connected with the organization of interruptions appearing in the cases of failures and as a reaction for the end of operation of any algol program or some of its links are considered

The effect of virtual reality training on unilateral spatial neglect in stroke patients.

Science.gov (United States)

Kim, Yong Mi; Chun, Min Ho; Yun, Gi Jeong; Song, Young Jin; Young, Han Eun

2011-06-01

To investigate the effect of virtual reality training on unilateral spatial neglect in stroke patients. Twenty-four stroke patients (14 males and 10 females, mean age=64.7) who had unilateral spatial neglect as a result of right hemisphere stroke were recruited. All patients were randomly assigned to either the virtual reality (VR) group (n=12) or the control group (n=12). The VR group received VR training, which stimulated the left side of their bodies. The control group received conventional neglect therapy such as visual scanning training. Both groups received therapy for 30 minutes a day, five days per week for three weeks. Outcome measurements included star cancellation test, line bisection test, Catherine Bergego scale (CBS), and the Korean version of modified Barthel index (K-MBI). These measurements were taken before and after treatment. There were no significant differences in the baseline characteristics and initial values between the two groups. The changes in star cancellation test results and CBS in the VR group were significantly higher than those of the control group after treatment. The changes in line bisection test score and the K-MBI in the VR group were not statistically significant. This study suggests that virtual reality training may be a beneficial therapeutic technique on unilateral spatial neglect in stroke patients.

Asymmetrical effects of adaptation to left- and right-shifting prisms depends on pre-existing attentional biases.

Science.gov (United States)

Goedert, Kelly M; Leblanc, Andrew; Tsai, Sen-Wei; Barrett, Anna M

2010-09-01

Proposals that adaptation with left-shifting prisms induces neglect-like symptoms in normal individuals rely on a dissociation between the postadaptation performance of individuals trained with left- versus right-shifting prisms (e.g., Colent, Pisella, & Rossetti, 2000). A potential problem with this evidence is that normal young adults have an a priori leftward bias (e.g., Jewell & McCourt, 2000). In Experiment 1, we compared the line bisection performance of young adults to that of aged adults, who as a group may lack a leftward bias in line bisection. Participants trained with both left- and right-shifting prisms. Consistent with our hypothesis, while young adults demonstrated aftereffects for left, but not right prisms, aged adults demonstrated reliable aftereffects for both prisms. In Experiment 2, we recruited a larger sample of young adults, some of whom were right-biased at baseline. We observed an interaction between baseline bias and prism-shift, consistent with the results of Experiment 1: Left-biased individuals showed a reduced aftereffect when training with right-shifting prisms and right-biased individuals showed a reduced aftereffect when training with left-shifting prisms. These results suggest that previous failures to find generalizable aftereffects with right-shifting prisms may be driven by participants' baseline biases rather than specific effects of the prism itself.

Engineering task plan for BX/BY compressor upgrade

International Nuclear Information System (INIS)

Strand, R.G.

1995-01-01

This Engineering Task Plan outlines the remaining work to be completed for the BX/BY Instrument Air upgrade. Initial work efforts were guided by Engineering Work Plan, ''BX-BY Compressor Upgrade'' dated 1-25-93 (see Attachment A) which is provided for information. The overall engineering task is to provide a permanent replacement for the instrument air supply system for the 241-BX/BY Tank Farms. The existing system consists of a 25 horsepower Worthington non-lube compressor and an Oriad air dryer. The existing equipment is dated, requires high maintenance and is located in a contaminated zone making it unusable. The BX/BY instrument air replacement unit will be one of the 100 SCFM generic air stations. This station will be permanently sited with the addition of drawing changes to provide a concrete foundation, air piping to existing lines and electrical power supply tie-ins

Dynamics of the central bottleneck: dual-task and task uncertainty.

Directory of Open Access Journals (Sweden)

Mariano Sigman

2006-07-01

Full Text Available Why is the human brain fundamentally limited when attempting to execute two tasks at the same time or in close succession? Two classical paradigms, psychological refractory period (PRP and task switching, have independently approached this issue, making significant advances in our understanding of the architecture of cognition. Yet, there is an apparent contradiction between the conclusions derived from these two paradigms. The PRP paradigm, on the one hand, suggests that the simultaneous execution of two tasks is limited solely by a passive structural bottleneck in which the tasks are executed on a first-come, first-served basis. The task-switching paradigm, on the other hand, argues that switching back and forth between task configurations must be actively controlled by a central executive system (the system controlling voluntary, planned, and flexible action. Here we have explicitly designed an experiment mixing the essential ingredients of both paradigms: task uncertainty and task simultaneity. In addition to a central bottleneck, we obtain evidence for active processes of task setting (planning of the appropriate sequence of actions and task disengaging (suppression of the plan set for the first task in order to proceed with the next one. Our results clarify the chronometric relations between these central components of dual-task processing, and in particular whether they operate serially or in parallel. On this basis, we propose a hierarchical model of cognitive architecture that provides a synthesis of task-switching and PRP paradigms.

Monitoring supports performance in a dual-task paradigm involving a risky decision-making task and a working memory task

Directory of Open Access Journals (Sweden)

Bettina eGathmann

2015-02-01

Full Text Available Performing two cognitively demanding tasks at the same time is known to decrease performance. The current study investigates the underlying executive functions of a dual-tasking situation involving the simultaneous performance of decision making under explicit risk and a working memory task. It is suggested that making a decision and performing a working memory task at the same time should particularly require monitoring - an executive control process supervising behavior and the state of processing on two tasks. To test the role of a supervisory/monitoring function in such a dual-tasking situation we investigated 122 participants with the Game of Dice Task plus 2-back task (GDT plus 2-back task. This dual task requires participants to make decisions under risk and to perform a 2-back working memory task at the same time. Furthermore, a task measuring a set of several executive functions gathered in the term concept formation (Modified Card Sorting Test, MCST and the newly developed Balanced Switching Task (BST, measuring monitoring in particular, were used. The results demonstrate that concept formation and monitoring are involved in the simultaneous performance of decision making under risk and a working memory task. In particular, the mediation analysis revealed that BST performance partially mediates the influence of MCST performance on the GDT plus 2-back task. These findings suggest that monitoring is one important subfunction for superior performance in a dual-tasking situation including decision making under risk and a working memory task.

Monitoring supports performance in a dual-task paradigm involving a risky decision-making task and a working memory task

Science.gov (United States)

Gathmann, Bettina; Schiebener, Johannes; Wolf, Oliver T.; Brand, Matthias

2015-01-01

Performing two cognitively demanding tasks at the same time is known to decrease performance. The current study investigates the underlying executive functions of a dual-tasking situation involving the simultaneous performance of decision making under explicit risk and a working memory task. It is suggested that making a decision and performing a working memory task at the same time should particularly require monitoring—an executive control process supervising behavior and the state of processing on two tasks. To test the role of a supervisory/monitoring function in such a dual-tasking situation we investigated 122 participants with the Game of Dice Task plus 2-back task (GDT plus 2-back task). This dual task requires participants to make decisions under risk and to perform a 2-back working memory task at the same time. Furthermore, a task measuring a set of several executive functions gathered in the term concept formation (Modified Card Sorting Test, MCST) and the newly developed Balanced Switching Task (BST), measuring monitoring in particular, were used. The results demonstrate that concept formation and monitoring are involved in the simultaneous performance of decision making under risk and a working memory task. In particular, the mediation analysis revealed that BST performance partially mediates the influence of MCST performance on the GDT plus 2-back task. These findings suggest that monitoring is one important subfunction for superior performance in a dual-tasking situation including decision making under risk and a working memory task. PMID:25741308

Environmental management technology demonstration and commercialization: Tasks 2, 3, 4, and 8. Semiannual report, October 1994--March 1995

International Nuclear Information System (INIS)

Hawthorne, S.B.; Ness, R.O. Jr.; Nowok, J.W.; Pflughoeft-Hassett, D.; Hurley, J.P.; Steadman, E.N.

1995-05-01

The objective of the Environmental Management program at the Energy and Environmental Research Center (EERC) is to develop, demonstrate, and commercialize technologies that address the environmental management needs of contaminated sites, including characterization, sensors, and monitoring; low-level mixed waste processing; material disposition technology; improved waste forms; in situ containment and remediation; and efficient separation technologies for radioactive wastes. Task 2 is the extraction and analysis of pollutant organics from contaminated solids using off-line supercritical fluid extraction (SFE) and on-line SFE-infrared spectroscopy. Task 3, pyrolysis of plastics, has as its objectives to develop a commercial process to significantly reduce the volume of mixed-plastics-paper-resin waste contaminated with low-level radioactive material; concentrate contaminants in a collectible form; and determine the distribution and form of contaminants after pyrolysis of the mixed waste. Task 4, stabilization of vitrified wastes, has as its objectives to (1) demonstrate a waste vitrification procedure for enhanced stabilization of waste materials and (2) develop a testing protocol to understand the long-term leaching behavior of the stabilized waste form. The primary objective of Task 8, Management and reporting, is coordination of this project with other programs and opportunities. In addition, management oversight will be maintained to ensure that tasks are completed and coordinated as planned and that deliverables are submitted in a timely manner. Accomplishments to date is each task are described. 62 refs

Sex differences on a measure of conformity in automated teller machine lines.

Science.gov (United States)

Reysen, Stephen; Reysen, Matthew B

2004-10-01

Sex differences in conformity were examined as participants approached two ATMs, one of which was occupied by three confederates and the other immediately available. The number of men and women in the line in front of one of the ATMs was manipulated (3 men or 3 women), and an unobtrusive observer recorded the sex of each participant. The results indicated that women were more likely than men to wait in line to use the ATM regardless of the makeup of the line. Thus, the present study provides evidence in favor of the idea that sex differences in conformity are evident on a common task performed in a natural setting.

The effects of stimulus modality and task integrality: Predicting dual-task performance and workload from single-task levels

Science.gov (United States)

Hart, S. G.; Shively, R. J.; Vidulich, M. A.; Miller, R. C.

1986-01-01

The influence of stimulus modality and task difficulty on workload and performance was investigated. The goal was to quantify the cost (in terms of response time and experienced workload) incurred when essentially serial task components shared common elements (e.g., the response to one initiated the other) which could be accomplished in parallel. The experimental tasks were based on the Fittsberg paradigm; the solution to a SternBERG-type memory task determines which of two identical FITTS targets are acquired. Previous research suggested that such functionally integrated dual tasks are performed with substantially less workload and faster response times than would be predicted by suming single-task components when both are presented in the same stimulus modality (visual). The physical integration of task elements was varied (although their functional relationship remained the same) to determine whether dual-task facilitation would persist if task components were presented in different sensory modalities. Again, it was found that the cost of performing the two-stage task was considerably less than the sum of component single-task levels when both were presented visually. Less facilitation was found when task elements were presented in different sensory modalities. These results suggest the importance of distinguishing between concurrent tasks that complete for limited resources from those that beneficially share common resources when selecting the stimulus modalities for information displays.

Resolving task rule incongruence during task switching by competitor rule suppression.

Science.gov (United States)

Meiran, Nachshon; Hsieh, Shulan; Dimov, Eduard

2010-07-01

Task switching requires maintaining readiness to execute any task of a given set of tasks. However, when tasks switch, the readiness to execute the now-irrelevant task generates interference, as seen in the task rule incongruence effect. Overcoming such interference requires fine-tuned inhibition that impairs task readiness only minimally. In an experiment involving 2 object classification tasks and 2 location classification tasks, the authors show that irrelevant task rules that generate response conflicts are inhibited. This competitor rule suppression (CRS) is seen in response slowing in subsequent trials, when the competing rules become relevant. CRS is shown to operate on specific rules without affecting similar rules. CRS and backward inhibition, which is another inhibitory phenomenon, produced additive effects on reaction time, suggesting their mutual independence. Implications for current formal theories of task switching as well as for conflict monitoring theories are discussed. (c) 2010 APA, all rights reserved

Sex differences in mental rotation and line angle judgments are positively associated with gender equality and economic development across 53 nations.

Science.gov (United States)

Lippa, Richard A; Collaer, Marcia L; Peters, Michael

2010-08-01

Mental rotation and line angle judgment performance were assessed in more than 90,000 women and 111,000 men from 53 nations. In all nations, men's mean performance exceeded women's on these two visuospatial tasks. Gender equality (as assessed by United Nations indices) and economic development (as assessed by per capita income and life expectancy) were significantly associated, across nations, with larger sex differences, contrary to the predictions of social role theory. For both men and women, across nations, gender equality and economic development were significantly associated with better performance on the two visuospatial tasks. However, these associations were stronger for the mental rotation task than for the line angle judgment task, and they were stronger for men than for women. Results were discussed in terms of evolutionary, social role, and stereotype threat theories of sex differences.

Flow line asymmetric nonimaging concentrating optics

Science.gov (United States)

Jiang, Lun; Winston, Roland

2016-09-01

Nonimaging Optics has shown that it achieves the theoretical limits by utilizing thermodynamic principles rather than conventional optics. Hence in this paper the condition of the "best" design are both defined and fulfilled in the framework of thermodynamic arguments, which we believe has profound consequences for the designs of thermal and even photovoltaic systems, even illumination and optical communication tasks. This new way of looking at the problem of efficient concentration depends on probabilities, geometric flux field and radiative heat transfer while "optics" in the conventional sense recedes into the background. Some of the new development of flow line designs will be introduced and the connection between the thermodynamics and flow line design will be officially formulated in the framework of geometric flux field. A new way of using geometric flux to design nonimaging optics will be introduced. And finally, we discuss the possibility of 3D ideal nonimaing optics.

Controlling maximum evaluation duration in on-line and on-board evolutionary robotics

NARCIS (Netherlands)

Atta-ul-Qayyum, A.; Nedev, D.G.; Haasdijk, E.W.

2014-01-01

On-line evolution of robot controllers allows robots to adapt while they perform their proper tasks. In our investigations, robots contain their own self-sufficient evolutionary algorithm (known as the encapsulated approach) where individual solutions are evaluated by means of a time sharing scheme:

Development of a hospital mobile platform for logistics tasks

Directory of Open Access Journals (Sweden)

Carlos Antonio Acosta Calderon

2015-04-01

Full Text Available Healthcare services heavily rely on healthcare staff and subsequently, there is the need to improve healthcare staff׳s workflow. The deployment of an automated mobile base will help enhance the productivity of logistics tasks in the hospital, like collection and delivery. By improving such logistic tasks healthcare personal is able to focus on other tasks to serve the community better. Currently there are commercial solutions to deal with these logistic tasks, where a mobile base is able to move from one place to another in a structured environment like a hospital. In this paper, we present our approach to develop a cost effective mobile base to be used for delivery in healthcare amenities. The proposed approach is able to navigate among stations in the hospital by first creating a map of the floor and then indicating the location of these stations. This reduces the additional cost of drawing lines on the floor or to put laser markers and many of the commercial solutions required. In addition, the proposed solution is able to navigate while being safe for the people moving around and to the transported items. The paper discusses the design consideration of the system, the navigation and the battery management to ensure that the system is able to run autonomously without the need recharge often.

The control of deliberate waiting strategies in a stop-signal task

Directory of Open Access Journals (Sweden)

R.P. Sylwan

2004-06-01

Full Text Available To inhibit an ongoing flow of thoughts or actions has been largely considered to be a crucial executive function, and the stop-signal paradigm makes inhibitory control measurable. Stop-signal tasks usually combine two concurrent tasks, i.e., manual responses to a primary task (go-task are occasionally countermanded by a stimulus which signals participants to inhibit their response in that trial (stop-task. Participants are always instructed not to wait for the stop-signal, since waiting strategies cause the response times to be unstable, invalidating the data. The aim of the present study was to experimentally control the strategies of waiting deliberately for the stop-signal in a stop-task by means of an algorithm that measured the variation in the reaction times to go-stimuli on-line, and displayed a warning legend urging participants to be faster when their reaction times were more than two standard deviations of the mean. Thirty-four university students performed a stop-task with go- and stop-stimuli, both of which were delivered in the visual modality and were lateralized within the visual field. The participants were divided into two groups (group A, without the algorithm, vs group B, with the algorithm. Group B exhibited lower variability of reaction times to go-stimuli, whereas no significant between-group differences were found in any of the measures of inhibitory control, showing that the algorithm succeeded in controlling the deliberate waiting strategies. Differences between deliberate and unintentional waiting strategies, and anxiety as a probable factor responsible for individual differences in deliberate waiting behavior, are discussed.

Visual coherence for large-scale line-plot visualizations

KAUST Repository

Muigg, Philipp

2011-06-01

Displaying a large number of lines within a limited amount of screen space is a task that is common to many different classes of visualization techniques such as time-series visualizations, parallel coordinates, link-node diagrams, and phase-space diagrams. This paper addresses the challenging problems of cluttering and overdraw inherent to such visualizations. We generate a 2x2 tensor field during line rasterization that encodes the distribution of line orientations through each image pixel. Anisotropic diffusion of a noise texture is then used to generate a dense, coherent visualization of line orientation. In order to represent features of different scales, we employ a multi-resolution representation of the tensor field. The resulting technique can easily be applied to a wide variety of line-based visualizations. We demonstrate this for parallel coordinates, a time-series visualization, and a phase-space diagram. Furthermore, we demonstrate how to integrate a focus+context approach by incorporating a second tensor field. Our approach achieves interactive rendering performance for large data sets containing millions of data items, due to its image-based nature and ease of implementation on GPUs. Simulation results from computational fluid dynamics are used to evaluate the performance and usefulness of the proposed method. © 2011 The Author(s).

Visual coherence for large-scale line-plot visualizations

KAUST Repository

Muigg, Philipp; Hadwiger, Markus; Doleisch, Helmut; Grö ller, Eduard M.

2011-01-01

Displaying a large number of lines within a limited amount of screen space is a task that is common to many different classes of visualization techniques such as time-series visualizations, parallel coordinates, link-node diagrams, and phase-space diagrams. This paper addresses the challenging problems of cluttering and overdraw inherent to such visualizations. We generate a 2x2 tensor field during line rasterization that encodes the distribution of line orientations through each image pixel. Anisotropic diffusion of a noise texture is then used to generate a dense, coherent visualization of line orientation. In order to represent features of different scales, we employ a multi-resolution representation of the tensor field. The resulting technique can easily be applied to a wide variety of line-based visualizations. We demonstrate this for parallel coordinates, a time-series visualization, and a phase-space diagram. Furthermore, we demonstrate how to integrate a focus+context approach by incorporating a second tensor field. Our approach achieves interactive rendering performance for large data sets containing millions of data items, due to its image-based nature and ease of implementation on GPUs. Simulation results from computational fluid dynamics are used to evaluate the performance and usefulness of the proposed method. © 2011 The Author(s).

Applying a Modified Triad Approach to Investigate Wastewater lines

International Nuclear Information System (INIS)

Pawlowicz, R.; Urizar, L.; Blanchard, S.; Jacobsen, K.; Scholfield, J.

2006-01-01

Approximately 20 miles of wastewater lines are below grade at an active military Base. This piping network feeds or fed domestic or industrial wastewater treatment plants on the Base. Past wastewater line investigations indicated potential contaminant releases to soil and groundwater. Further environmental assessment was recommended to characterize the lines because of possible releases. A Remedial Investigation (RI) using random sampling or use of sampling points spaced at predetermined distances along the entire length of the wastewater lines, however, would be inefficient and cost prohibitive. To accomplish RI goals efficiently and within budget, a modified Triad approach was used to design a defensible sampling and analysis plan and perform the investigation. The RI task was successfully executed and resulted in a reduced fieldwork schedule, and sampling and analytical costs. Results indicated that no major releases occurred at the biased sampling points. It was reasonably extrapolated that since releases did not occur at the most likely locations, then the entire length of a particular wastewater line segment was unlikely to have contaminated soil or groundwater and was recommended for no further action. A determination of no further action was recommended for the majority of the waste lines after completing the investigation. The modified Triad approach was successful and a similar approach could be applied to investigate wastewater lines on other United States Department of Defense or Department of Energy facilities. (authors)

Towards Product Lining Model-Driven Development Code Generators

OpenAIRE

Roth, Alexander; Rumpe, Bernhard

2015-01-01

A code generator systematically transforms compact models to detailed code. Today, code generation is regarded as an integral part of model-driven development (MDD). Despite its relevance, the development of code generators is an inherently complex task and common methodologies and architectures are lacking. Additionally, reuse and extension of existing code generators only exist on individual parts. A systematic development and reuse based on a code generator product line is still in its inf...

Contaminated sediment research task: SHC Task 3.61.3

Science.gov (United States)

A poster presentation for the SHC BOSC review will summarize the research efforts under Sustainable and Healthy Communities Research Program (SHC) in the Contaminated Sediment Task within the Contaminated Sites Project. For the Task, Problem Summary & Decision Context; Task O...

Counting on the mental number line to make a move: sensorimotor ('pen') control and numerical processing.

Science.gov (United States)

Sheridan, Rebecca; van Rooijen, Maaike; Giles, Oscar; Mushtaq, Faisal; Steenbergen, Bert; Mon-Williams, Mark; Waterman, Amanda

2017-10-01

Mathematics is often conducted with a writing implement. But is there a relationship between numerical processing and sensorimotor 'pen' control? We asked participants to move a stylus so it crossed an unmarked line at a location specified by a symbolic number (1-9), where number colour indicated whether the line ran left-right ('normal') or vice versa ('reversed'). The task could be simplified through the use of a 'mental number line' (MNL). Many modern societies use number lines in mathematical education and the brain's representation of number appears to follow a culturally determined spatial organisation (so better task performance is associated with this culturally normal orientation-the MNL effect). Participants (counter-balanced) completed two consistent blocks of trials, 'normal' and 'reversed', followed by a mixed block where line direction varied randomly. Experiment 1 established that the MNL effect was robust, and showed that the cognitive load associated with reversing the MNL not only affected response selection but also the actual movement execution (indexed by duration) within the mixed trials. Experiment 2 showed that an individual's motor abilities predicted performance in the difficult (mixed) condition but not the easier blocks. These results suggest that numerical processing is not isolated from motor capabilities-a finding with applied consequences.

Residual standard deviation: Validation of a new measure of dual-task cost in below-knee prosthesis users.

Science.gov (United States)

Howard, Charla L; Wallace, Chris; Abbas, James; Stokic, Dobrivoje S

2017-01-01

We developed and evaluated properties of a new measure of variability in stride length and cadence, termed residual standard deviation (RSD). To calculate RSD, stride length and cadence are regressed against velocity to derive the best fit line from which the variability (SD) of the distance between the actual and predicted data points is calculated. We examined construct, concurrent, and discriminative validity of RSD using dual-task paradigm in 14 below-knee prosthesis users and 13 age- and education-matched controls. Subjects walked first over an electronic walkway while performing separately a serial subtraction and backwards spelling task, and then at self-selected slow, normal, and fast speeds used to derive the best fit line for stride length and cadence against velocity. Construct validity was demonstrated by significantly greater increase in RSD during dual-task gait in prosthesis users than controls (group-by-condition interaction, stride length p=0.0006, cadence p=0.009). Concurrent validity was established against coefficient of variation (CV) by moderate-to-high correlations (r=0.50-0.87) between dual-task cost RSD and dual-task cost CV for both stride length and cadence in prosthesis users and controls. Discriminative validity was documented by the ability of dual-task cost calculated from RSD to effectively differentiate prosthesis users from controls (area under the receiver operating characteristic curve, stride length 0.863, p=0.001, cadence 0.808, p=0.007), which was better than the ability of dual-task cost CV (0.692, 0.648, respectively, not significant). These results validate RSD as a new measure of variability in below-knee prosthesis users. Future studies should include larger cohorts and other populations to ascertain its generalizability. Copyright © 2016 Elsevier B.V. All rights reserved.

Combining environment-driven adaptation and task-driven optimisation in evolutionary robotics.

Science.gov (United States)

Haasdijk, Evert; Bredeche, Nicolas; Eiben, A E

2014-01-01

Embodied evolutionary robotics is a sub-field of evolutionary robotics that employs evolutionary algorithms on the robotic hardware itself, during the operational period, i.e., in an on-line fashion. This enables robotic systems that continuously adapt, and are therefore capable of (re-)adjusting themselves to previously unknown or dynamically changing conditions autonomously, without human oversight. This paper addresses one of the major challenges that such systems face, viz. that the robots must satisfy two sets of requirements. Firstly, they must continue to operate reliably in their environment (viability), and secondly they must competently perform user-specified tasks (usefulness). The solution we propose exploits the fact that evolutionary methods have two basic selection mechanisms-survivor selection and parent selection. This allows evolution to tackle the two sets of requirements separately: survivor selection is driven by the environment and parent selection is based on task-performance. This idea is elaborated in the Multi-Objective aNd open-Ended Evolution (monee) framework, which we experimentally validate. Experiments with robotic swarms of 100 simulated e-pucks show that monee does indeed promote task-driven behaviour without compromising environmental adaptation. We also investigate an extension of the parent selection process with a 'market mechanism' that can ensure equitable distribution of effort over multiple tasks, a particularly pressing issue if the environment promotes specialisation in single tasks.

Combining environment-driven adaptation and task-driven optimisation in evolutionary robotics.

Directory of Open Access Journals (Sweden)

Evert Haasdijk

Full Text Available Embodied evolutionary robotics is a sub-field of evolutionary robotics that employs evolutionary algorithms on the robotic hardware itself, during the operational period, i.e., in an on-line fashion. This enables robotic systems that continuously adapt, and are therefore capable of (re-adjusting themselves to previously unknown or dynamically changing conditions autonomously, without human oversight. This paper addresses one of the major challenges that such systems face, viz. that the robots must satisfy two sets of requirements. Firstly, they must continue to operate reliably in their environment (viability, and secondly they must competently perform user-specified tasks (usefulness. The solution we propose exploits the fact that evolutionary methods have two basic selection mechanisms-survivor selection and parent selection. This allows evolution to tackle the two sets of requirements separately: survivor selection is driven by the environment and parent selection is based on task-performance. This idea is elaborated in the Multi-Objective aNd open-Ended Evolution (monee framework, which we experimentally validate. Experiments with robotic swarms of 100 simulated e-pucks show that monee does indeed promote task-driven behaviour without compromising environmental adaptation. We also investigate an extension of the parent selection process with a 'market mechanism' that can ensure equitable distribution of effort over multiple tasks, a particularly pressing issue if the environment promotes specialisation in single tasks.

Using the NASA Task Load Index to Assess Workload in Electronic Medical Records.

Science.gov (United States)

Hudson, Darren; Kushniruk, Andre W; Borycki, Elizabeth M

2015-01-01

Electronic medical records (EMRs) has been expected to decrease health professional workload. The NASA Task Load Index has become an important tool for assessing workload in many domains. However, its application in assessing the impact of an EMR on nurse's workload has remained to be explored. In this paper we report the results of a study of workload and we explore the utility of applying the NASA Task Load Index to assess impact of an EMR at the end of its lifecycle on nurses' workload. It was found that mental and temporal demands were the most responsible for the workload. Further work along these lines is recommended.

Does compliance to patient safety tasks improve and sustain when radiotherapy treatment processes are standardized?

Science.gov (United States)

Simons, Pascale A M; Houben, Ruud; Benders, Jos; Pijls-Johannesma, Madelon; Vandijck, Dominique; Marneffe, Wim; Backes, Huub; Groothuis, Siebren

2014-10-01

To realize safe radiotherapy treatment, processes must be stabilized. Standard operating procedures (SOP's) were expected to stabilize the treatment process and perceived task importance would increase sustainability in compliance. This paper presents the effects on compliance to safety related tasks of a process redesign based on lean principles. Compliance to patient safety tasks was measured by video recording of actual radiation treatment, before (T0), directly after (T1) and 1.5 years after (T2) a process redesign. Additionally, technologists were surveyed on perceived task importance and reported incidents were collected for three half-year periods between 2007 and 2009. Compliance to four out of eleven tasks increased at T1, of which improvements on three sustained (T2). Perceived importance of tasks strongly correlated (0.82) to compliance rates at T2. The two tasks, perceived as least important, presented low base-line compliance, improved (T1), but relapsed at T2. The reported near misses (patient-level not reached) on accelerators increased (P improvements sustained after 1.5 years, indicating increased stability. Perceived importance of tasks correlated positively to compliance and sustainability. Raising the perception of task importance is thus crucial to increase compliance. The redesign resulted in increased willingness to report incidents, creating opportunities for patient safety improvement in radiotherapy treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cognitive task analysis

NARCIS (Netherlands)

Schraagen, J.M.C.

2000-01-01

Cognitive task analysis is defined as the extension of traditional task analysis techniques to yield information about the knowledge, thought processes and goal structures that underlie observable task performance. Cognitive task analyses are conducted for a wide variety of purposes, including the

Prediction of temperature-insensitive molecular absorption lines in laser-assisted combustion diagnostics

International Nuclear Information System (INIS)

Walewski, Joachim W.; Elmqvist, Anders

2005-01-01

In laser-assisted combustion diagnostics it is a recurring task to predict molecular transitions whose signal strength depends only weakly on variations in temperature. The signal strength is proportional to the Boltzmann fraction of the level probed and the amplitude of the absorption line profile. In the past investigations have been presented in which this task was attack by detailed numerical calculations of the temperature dependence of pertinent physical properties of the molecule. Another widely applied approach relies on an analytical formula for the Boltzmann fraction of hetero-nuclear diatomic molecules and the neglect of line shape effects. The analytical approach experiences a continuing popularity in laser-assisted combustion diagnostics, which is why we compared both approaches with each other. The objective of this comparison was to assess the accuracy of the analytical approach and to reveal its potential pitfalls. Our comparison revealed that the analytical approach suffers from mediocre accuracy, which makes it unfit for practical applications. One cause is the neglect of higher lying vibrational levels, which show a non-negligible population for typical flame temperatures. Another reason is the neglect of fine structure splitting in molecules with non-zero orbit angular momentum in the ground state. Another reason for the observed inaccuracy is the neglect of line shape effects quenching, which were found to have a significant effect on the temperature sensitivity of a line. Because of its insufficient accuracy due to both oversimplified models of the molecular energy levels and the neglect of line shape effects and quenching we discourage from applying the analytical approach and recommend the use of detailed numerical approaches that are free of the above limitations

It's about time: revisiting temporal processing deficits in dyslexia.

Science.gov (United States)

Casini, Laurence; Pech-Georgel, Catherine; Ziegler, Johannes C

2018-03-01

Temporal processing in French children with dyslexia was evaluated in three tasks: a word identification task requiring implicit temporal processing, and two explicit temporal bisection tasks, one in the auditory and one in the visual modality. Normally developing children matched on chronological age and reading level served as a control group. Children with dyslexia exhibited robust deficits in temporal tasks whether they were explicit or implicit and whether they involved the auditory or the visual modality. First, they presented larger perceptual variability when performing temporal tasks, whereas they showed no such difficulties when performing the same task on a non-temporal dimension (intensity). This dissociation suggests that their difficulties were specific to temporal processing and could not be attributed to lapses of attention, reduced alertness, faulty anchoring, or overall noisy processing. In the framework of cognitive models of time perception, these data point to a dysfunction of the 'internal clock' of dyslexic children. These results are broadly compatible with the recent temporal sampling theory of dyslexia. © 2017 John Wiley & Sons Ltd.

Children's Task Engagement during Challenging Puzzle Tasks

Science.gov (United States)

Wang, Feihong; Algina, James; Snyder, Patricia; Cox, Martha

2017-01-01

We examined children's task engagement during a challenging puzzle task in the presence of their primary caregivers by using a representative sample of rural children from six high-poverty counties across two states. Weighted longitudinal confirmatory factor analysis and structural equation modeling were used to identify a task engagement factor…

Dual-tasking over an extended walking distance is associated with falls among community-dwelling older adults

Directory of Open Access Journals (Sweden)

Hirashima K

2015-04-01

Full Text Available Kenichi Hirashima,1,2 Yumi Higuchi,1 Masakazu Imaoka,1 Emiko Todo,1 Tomomi Kitagawa,1 Tetsuya Ueda11Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino Campus, Habikino City, Osaka, Japan; 2Faculty of Health and Welfare, Department of Physical Therapy, Tokushima Bunri University, Nishihamaboji, Yamashiro Town, Tokushima City, Tokushima, Japan Aim: Dual-task methods, in which walking is the primary task, are not sufficient for accurately screening for the risk of falls among healthy older adults. Therefore, the goal of this research was to investigate whether using a dual-task method over an extended walking distance can predict falls among community-dwelling older adults.Methods: We enrolled independent community-dwelling adults aged ≥65 years. Physical performance, cognitive function, psychological function, and a dual-task test were assessed at baseline. Our dual-task test required the subjects to walk 60 m while stepping over lines. The intervals between the lines ranged from 50–100 cm and were unequal. Falls and fall-related injuries were measured over a 12-month follow-up period using monthly postal surveys. Results: Ninety-two of 118 subjects (mean age, 75.4±5.5 years completed the 12-month follow-up. Sixteen (17.4% of fallers had injurious falls or fell more than or equal to two times. There were no significant differences between the fallers and non-fallers, except in age and in the number of missteps during the dual-task test when walking ≥40 m. The Kaplan–Meier analysis revealed that those who had more than one misstep while walking ≥40 m had a significantly higher incidence of injurious or multiple falls than those who had no missteps.Conclusion: Our findings suggest that the dual-task method with an extended walking distance may be able to predict falls among community-dwelling older adults. Keywords: cohort study, community-dwelling older adults, dual-task, falls

RF model of the distribution system as a communication channel, phase 2. Volume 2: Task reports

Science.gov (United States)

Rustay, R. C.; Gajjar, J. T.; Rankin, R. W.; Wentz, R. C.; Wooding, R.

1982-01-01

Based on the established feasibility of predicting, via a model, the propagation of Power Line Frequency on radial type distribution feeders, verification studies comparing model predictions against measurements were undertaken using more complicated feeder circuits and situations. Detailed accounts of the major tasks are presented. These include: (1) verification of model; (2) extension, implementation, and verification of perturbation theory; (3) parameter sensitivity; (4) transformer modeling; and (5) compensation of power distribution systems for enhancement of power line carrier communication reliability.

On-Line Monitoring of Instrument Channel Performance: Volume 3: Applications to Nuclear Power Plant Technical Specification Instrumentation

International Nuclear Information System (INIS)

Davis, E.; Rasmussen, B.

2004-01-01

This report is a guide for a technical specification change submittal and subsequent implementation of on-line monitoring for safety-related applications. This report is the third in a three-volume set. Volume 1, ''Guidelines for Model Development and Implementation'', presents the various tasks that must be completed to prepare models for and to implement an on-line monitoring system

On-line analysis of water contamination by organic compounds; On-line-Analytik der Wasserverschmutzung durch organische Substanzen

Energy Technology Data Exchange (ETDEWEB)

Wagt, R. van der; Vos, F. de [Skalar Analytical (Netherlands); Babichenko, S.; Poryvkina, L. [Institute of Ecology, Tallinn (Estonia)

1999-08-01

In many environmental applications decomposing the mixture of substances in the water into its various chemical ingredients, for subsequent analysis, is a very complicated task. The most productive approach to on-line diagnosis is to treat the object as an integral spectroscopic sample, characterized by certain specific Spectral Fluorescent Signatures (SFS). The SFS are recorded as a matrix of fluorescent intensity of organic compounds in water, in co-ordinates of excitation and emission spectra, providing a three-dimensional spectrum. Spectral windows of SFS are defined by fluorescent characteristics of basic groups of organic substances in the water sample. The novel Skalar Fluo Imager, based on this principle, is intended for the analysis of organic compounds in natural, domestic, and technological waters in an on-line mode. (orig.) [German] In vielen Umweltschutzanwendungen stellt die Auftrennung eines Substanzgemisches zum Zweck der Analyse eine sehr komplizierte Aufgabe dar. Ein erfolgversprechender Ansatz fuer eine on-line-Diagnostik besteht darin, das Objekt als integrale Spektroskopieprobe zu betrachten, die durch bestimmte spezifische Spektral-Fluoreszenz-Signaturen (SFS) charakterisiert wird. Diese werden als Fluoreszenz-Intensitaets-Matrix organischer Verbindungen in Wasser dargestellt, mit Anregungs- und Emissionsspektren als weiteren Koordinaten, wodurch ein dreidimensionales Spektrum entsteht. Spektrale Fenster der SFS sind definiert als Fluoreszenzcharakteristika von Funktionsgruppen organischer Substanzen in der Wasserprobe. Der auf diesem Prinzip basierende Skalar Fluo Imager ist fuer die on-line-Analyse organischer Bestandteile in natuerlichen, Haus- und technischen Waessern gedacht. (orig.)

Calculation of the Magnetic Fields of the Electric Power Line

Directory of Open Access Journals (Sweden)

Patsiuk V.

2016-12-01

Full Text Available The task of calculation of per unit length parameters of multi-conductor electrical overhead transmission lines has been treated in the paper. The calculation of distribution of electric and magnetic fields has been performed by means of the finite volume method for entire span of the line. The theoretical justification of the method for calculation the parameters of electromagnetic field taking into account the change of the vector of magnetic potential along the line has been given. The problems of electrostatic and magnetostatic for a single electric conductor and unlimited long conductor with current have been solved. For the inner and total inductivities of a single conductor under the current have been obtained relationships and drawn dependences. Dependence between the speeds of light and of electromagnetic wave’s propagation has been presented. Based on the characteristics of distribution of electric and magnetic fields of multi-conductor lines has been provided the method of calculation of the matrix of own and mutual capacitances and inductivities the calculated values of per unit length parameters of compact 110 kV electric line which is in concordance with one of basic physical constant – the speed of light.

Mental workload and cognitive task automaticity: an evaluation of subjective and time estimation metrics.

Science.gov (United States)

Liu, Y; Wickens, C D

1994-11-01

The evaluation of mental workload is becoming increasingly important in system design and analysis. The present study examined the structure and assessment of mental workload in performing decision and monitoring tasks by focusing on two mental workload measurements: subjective assessment and time estimation. The task required the assignment of a series of incoming customers to the shortest of three parallel service lines displayed on a computer monitor. The subject was either in charge of the customer assignment (manual mode) or was monitoring an automated system performing the same task (automatic mode). In both cases, the subjects were required to detect the non-optimal assignments that they or the computer had made. Time pressure was manipulated by the experimenter to create fast and slow conditions. The results revealed a multi-dimensional structure of mental workload and a multi-step process of subjective workload assessment. The results also indicated that subjective workload was more influenced by the subject's participatory mode than by the factor of task speed. The time estimation intervals produced while performing the decision and monitoring tasks had significantly greater length and larger variability than those produced while either performing no other tasks or performing a well practised customer assignment task. This result seemed to indicate that time estimation was sensitive to the presence of perceptual/cognitive demands, but not to response related activities to which behavioural automaticity has developed.

Participatory ergonomic intervention for prevention of low back pain: assembly line redesign case.

Science.gov (United States)

Bernardes, João Marcos; Wanderck, Claudia; Moro, Antônio Renato Pereira

2012-01-01

This paper gives an overview of a participatory ergonomic intervention aimed at reducing low back pain cases in the dispatch department of a catalogue and e-commerce retail company. Based on the findings of the ergonomic analysis and design committee, the company's own employees redesigned the assembly line's layout. As a result of these changes two job tasks that involved manual material handling of boxes, identified by the revised NIOSH equation as posing an increased risk for lifting-related low back pain, were totally eliminated, and the employees responsible for moving boxes from the end of the assembly line to pallets on the ground were given more control over their jobs, and these jobs were also enriched with a new, less heavy task. These results demonstrate that participatory ergonomic interventions are a viable and effective strategy to reduce the exposure to work-related physical and psychosocial risk factors for low back pain.

Effects of Task Complexity, Task Conditions, and Task Difficulty on the Grammatical Accuracy of EFL Learners in Written Discourse

Directory of Open Access Journals (Sweden)

Saeideh Ahangari

2012-11-01

Full Text Available Different methods of language teaching have tried to help EFL learners to develop good language skills based on their various perspectives. Research findings have underscored the effect of using task types in promoting language skills in terms of accuracy in written discourse. Therefore, this study set out to investigate whether there is an evidence of correct use of simple past tense (Accuracy based on Task Complexity (Task type :Here-and now & There-and-then,Task Conditions (Gender: Male & Female, and Task Difficulty (Proficiency: Lower-intermediate & Intermediate. Sixty Iranian English learners in a language institute participated in the study and were assigned to four groups of lower-intermediate male, lower-intermediate female, intermediate male and intermediate female. Initial homogeneity of the groups was verified using two general proficiency tests; KET for lower-intermediate and PET for intermediate. All groups in here-and-now task type were asked to write a story using simple past based on a picture strip while for there-and-then task type the participants were supposed to write about their last birthday. The results from paired samples t-test, independent samples t-test and two-way ANOVA analysis of the written data revealed significant differences in performing task types, at different proficiency levels and interaction between them. The findings have significant pedagogical implications for EFL learners to understand the relationship among Task Complexity,Task Conditions, Task Difficulty and L2 written production leading to various degrees of Accuracy.

Efficient production of a gene mutant cell line through integrating TALENs and high-throughput cell cloning.

Science.gov (United States)

Sun, Changhong; Fan, Yu; Li, Juan; Wang, Gancheng; Zhang, Hanshuo; Xi, Jianzhong Jeff

2015-02-01

Transcription activator-like effectors (TALEs) are becoming powerful DNA-targeting tools in a variety of mammalian cells and model organisms. However, generating a stable cell line with specific gene mutations in a simple and rapid manner remains a challenging task. Here, we report a new method to efficiently produce monoclonal cells using integrated TALE nuclease technology and a series of high-throughput cell cloning approaches. Following this method, we obtained three mTOR mutant 293T cell lines within 2 months, which included one homozygous mutant line. © 2014 Society for Laboratory Automation and Screening.

Measuring cognitive load: performance, mental effort and simulation task complexity.

Science.gov (United States)

Haji, Faizal A; Rojas, David; Childs, Ruth; de Ribaupierre, Sandrine; Dubrowski, Adam

2015-08-01

Interest in applying cognitive load theory in health care simulation is growing. This line of inquiry requires measures that are sensitive to changes in cognitive load arising from different instructional designs. Recently, mental effort ratings and secondary task performance have shown promise as measures of cognitive load in health care simulation. We investigate the sensitivity of these measures to predicted differences in intrinsic load arising from variations in task complexity and learner expertise during simulation-based surgical skills training. We randomly assigned 28 novice medical students to simulation training on a simple or complex surgical knot-tying task. Participants completed 13 practice trials, interspersed with computer-based video instruction. On trials 1, 5, 9 and 13, knot-tying performance was assessed using time and movement efficiency measures, and cognitive load was assessed using subjective rating of mental effort (SRME) and simple reaction time (SRT) on a vibrotactile stimulus-monitoring secondary task. Significant improvements in knot-tying performance (F(1.04,24.95)  = 41.1, p cognitive load (F(2.3,58.5)  = 57.7, p load among novices engaged in simulation-based learning. These measures can be used to track cognitive load during skills training. Mental effort ratings are also sensitive to small differences in intrinsic load arising from variations in the physical complexity of a simulation task. The complementary nature of these subjective and objective measures suggests their combined use is advantageous in simulation instructional design research. © 2015 John Wiley & Sons Ltd.

Cooperative endocytosis of the endosomal SNARE protein syntaxin-8 and the potassium channel TASK-1

Science.gov (United States)

Renigunta, Vijay; Fischer, Thomas; Zuzarte, Marylou; Kling, Stefan; Zou, Xinle; Siebert, Kai; Limberg, Maren M.; Rinné, Susanne; Decher, Niels; Schlichthörl, Günter; Daut, Jürgen

2014-01-01

The endosomal SNARE protein syntaxin-8 interacts with the acid-sensitive potassium channel TASK-1. The functional relevance of this interaction was studied by heterologous expression of these proteins (and mutants thereof) in Xenopus oocytes and in mammalian cell lines. Coexpression of syntaxin-8 caused a fourfold reduction in TASK-1 current, a corresponding reduction in the expression of TASK-1 at the cell surface, and a marked increase in the rate of endocytosis of the channel. TASK-1 and syntaxin-8 colocalized in the early endosomal compartment, as indicated by the endosomal markers 2xFYVE and rab5. The stimulatory effect of the SNARE protein on the endocytosis of the channel was abolished when both an endocytosis signal in TASK-1 and an endocytosis signal in syntaxin-8 were mutated. A syntaxin-8 mutant that cannot assemble with other SNARE proteins had virtually the same effect as wild-type syntaxin-8. Total internal reflection fluorescence microscopy showed formation and endocytosis of vesicles containing fluorescence-tagged clathrin, TASK-1, and/or syntaxin-8. Our results suggest that the unassembled form of syntaxin-8 and the potassium channel TASK-1 are internalized via clathrin-mediated endocytosis in a cooperative manner. This implies that syntaxin-8 regulates the endocytosis of TASK-1. Our study supports the idea that endosomal SNARE proteins can have functions unrelated to membrane fusion. PMID:24743596

Bisectional fault detection system

Science.gov (United States)

Archer, Charles Jens [Rochester, MN; Pinnow, Kurt Walter [Rochester, MN; Ratterman, Joseph D [Rochester, MN; Smith, Brian Edward [Rochester, MN

2009-08-04

An apparatus and program product logically divide a group of nodes and causes node pairs comprising a node from each section to communicate. Results from the communications may be analyzed to determine performance characteristics, such as bandwidth and proper connectivity.

Bisectional fault detection system

Science.gov (United States)

Archer, Charles Jens [Rochester, MN; Pinnow, Kurt Walter [Rochester, MN; Ratterman, Joseph D [Rochester, MN; Smith, Brian Edward [Rochester, MN

2008-11-11

An apparatus, program product and method logically divides a group of nodes and causes node pairs comprising a node from each section to communicate. Results from the communications may be analyzed to determine performance characteristics, such as bandwidth and proper connectivity.

Vessel Segmentation in Retinal Images Using Multi-scale Line Operator and K-Means Clustering.

Science.gov (United States)

Saffarzadeh, Vahid Mohammadi; Osareh, Alireza; Shadgar, Bita

2014-04-01

Detecting blood vessels is a vital task in retinal image analysis. The task is more challenging with the presence of bright and dark lesions in retinal images. Here, a method is proposed to detect vessels in both normal and abnormal retinal fundus images based on their linear features. First, the negative impact of bright lesions is reduced by using K-means segmentation in a perceptive space. Then, a multi-scale line operator is utilized to detect vessels while ignoring some of the dark lesions, which have intensity structures different from the line-shaped vessels in the retina. The proposed algorithm is tested on two publicly available STARE and DRIVE databases. The performance of the method is measured by calculating the area under the receiver operating characteristic curve and the segmentation accuracy. The proposed method achieves 0.9483 and 0.9387 localization accuracy against STARE and DRIVE respectively.

Walking modality, but not task difficulty, influences the control of dual-task walking.

Science.gov (United States)

Wrightson, J G; Smeeton, N J

2017-10-01

During dual-task gait, changes in the stride-to-stride variability of stride time (STV) are suggested to represent the allocation of cognitive control to walking [1]. However, contrasting effects have been reported for overground and treadmill walking, which may be due to differences in the relative difficulty of the dual task. Here we compared the effect of overground and treadmill dual-task walking on STV in 18 healthy adults. Participants walked overground and on a treadmill for 120s during single-task (walking only) and dual-task (walking whilst performing serial subtractions in sevens) conditions. Dual-task effects on STV, cognitive task (serial subtraction) performance and perceived task difficulty were compared between walking modalities. STV was increased during overground dual-task walking, but was unchanged during treadmill dual-task walking. There were no differences in cognitive task performance or perceived task difficulty. These results show that gait is controlled differently during overground and treadmill dual-task walking. However, these differences are not solely due to differences in task difficulty, and may instead represent modality dependent control strategies. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of tDCS on task relevant and irrelevant perceptual learning of complex objects.

Science.gov (United States)

Van Meel, Chayenne; Daniels, Nicky; de Beeck, Hans Op; Baeck, Annelies

2016-01-01

During perceptual learning the visual representations in the brain are altered, but these changes' causal role has not yet been fully characterized. We used transcranial direct current stimulation (tDCS) to investigate the role of higher visual regions in lateral occipital cortex (LO) in perceptual learning with complex objects. We also investigated whether object learning is dependent on the relevance of the objects for the learning task. Participants were trained in two tasks: object recognition using a backward masking paradigm and an orientation judgment task. During both tasks, an object with a red line on top of it were presented in each trial. The crucial difference between both tasks was the relevance of the object: the object was relevant for the object recognition task, but not for the orientation judgment task. During training, half of the participants received anodal tDCS stimulation targeted at the lateral occipital cortex (LO). Afterwards, participants were tested on how well they recognized the trained objects, the irrelevant objects presented during the orientation judgment task and a set of completely new objects. Participants stimulated with tDCS during training showed larger improvements of performance compared to participants in the sham condition. No learning effect was found for the objects presented during the orientation judgment task. To conclude, this study suggests a causal role of LO in relevant object learning, but given the rather low spatial resolution of tDCS, more research on the specificity of this effect is needed. Further, mere exposure is not sufficient to train object recognition in our paradigm.

78 FR 2996 - Meeting of the Community Preventive Services Task Force (Task Force)

Science.gov (United States)

2013-01-15

... Community Preventive Services Task Force (Task Force) AGENCY: Centers for Disease Control and Prevention... Services Task Force (Task Force). The Task Force is independent and nonfederal. Its members are nationally.... The Task Force was convened in 1996 by the Department of Health and Human Services (HHS) to assess the...

77 FR 56845 - Meeting of the Community Preventive Services Task Force (Task Force)

Science.gov (United States)

2012-09-14

... Community Preventive Services Task Force (Task Force) AGENCY: Centers for Disease Control and Prevention... Services Task Force (Task Force). The Task Force is independent and nonfederal. Its members are nationally.... The Task Force was convened in 1996 by the Department of Health and Human Services (HHS) to assess the...

78 FR 27969 - Meeting of the Community Preventive Services Task Force (Task Force)

Science.gov (United States)

2013-05-13

... Community Preventive Services Task Force (Task Force) AGENCY: Centers for Disease Control and Prevention... Services Task Force (Task Force). The Task Force is independent and nonfederal. Its members are nationally.... The Task Force was convened in 1996 by the Department of Health and Human Services (HHS) to assess the...

Beads task vs. box task: The specificity of the jumping to conclusions bias.

Science.gov (United States)

Balzan, Ryan P; Ephraums, Rachel; Delfabbro, Paul; Andreou, Christina

2017-09-01

Previous research involving the probabilistic reasoning 'beads task' has consistently demonstrated a jumping-to-conclusions (JTC) bias, where individuals with delusions make decisions based on limited evidence. However, recent studies have suggested that miscomprehension may be confounding the beads task. The current study aimed to test the conventional beads task against a conceptually simpler probabilistic reasoning "box task" METHODS: One hundred non-clinical participants completed both the beads task and the box task, and the Peters et al. Delusions Inventory (PDI) to assess for delusion-proneness. The number of 'draws to decision' was assessed for both tasks. Additionally, the total amount of on-screen evidence was manipulated for the box task, and two new box task measures were assessed (i.e., 'proportion of evidence requested' and 'deviation from optimal solution'). Despite being conceptually similar, the two tasks did not correlate, and participants requested significantly less information on the beads task relative to the box task. High-delusion-prone participants did not demonstrate hastier decisions on either task; in fact, for box task, this group was observed to be significantly more conservative than low-delusion-prone group. Neither task was incentivized; results need replication with a clinical sample. Participants, and particularly those identified as high-delusion-prone, displayed a more conservative style of responding on the novel box task, relative to the beads task. The two tasks, whilst conceptually similar, appear to be tapping different cognitive processes. The implications of these results are discussed in relation to the JTC bias and the theoretical mechanisms thought to underlie it. Copyright © 2016 Elsevier Ltd. All rights reserved.

Automatic Retrieval of Newly Instructed Cue-Task Associations Seen in Task-Conflict Effects in the First Trial after Cue-Task Instructions.

Science.gov (United States)

Meiran, Nachshon; Pereg, Maayan

2017-01-01

Novel stimulus-response associations are retrieved automatically even without prior practice. Is this true for novel cue-task associations? The experiment involved miniblocks comprising three phases and task switching. In the INSTRUCTION phase, two new stimuli (or familiar cues) were arbitrarily assigned as cues for up-down/right-left tasks performed on placeholder locations. In the UNIVALENT phase, there was no task cue since placeholder's location afforded one task but the placeholders were the stimuli that we assigned as task cues for the following BIVALENT phase (involving target locations affording both tasks). Thus, participants held the novel cue-task associations in memory while executing the UNIVALENT phase. Results show poorer performance in the first univalent trial when the placeholder was associated with the opposite task (incompatible) than when it was compatible, an effect that was numerically larger with newly instructed cues than with familiar cues. These results indicate automatic retrieval of newly instructed cue-task associations.

Derivation of Color Confusion Lines for Pseudo-Dichromat Observers from Color Discrimination Thresholds

Directory of Open Access Journals (Sweden)

Kahiro Matsudaira

2011-05-01

Full Text Available The objective is to develop a method of defining color confusion lines in the display RGB color space through color discrimination tasks. In the experiment, reference and test square patches were presented side by side on a CRT display. The subject's task is to set the test color where the color difference from the reference is just noticeable to him/her. In a single trial, the test color was only adjustable along one of 26 directions around the reference. Thus 26 colors with just noticeable difference (JND were obtained and made up a tube-like or an ellipsoidal shape around each reference. With color-anomalous subjects, the major axes of these shapes should be parallel to color confusion lines that have a common orientation vector corresponding to one of the cone excitation axes L, M, or S. In our method, the orientation vector was determined by minimizing the sum of the squares of the distances from JND colors to each confusion line. To assess the performance the method, the orientation vectors obtained by pseudo-dichromats (color normal observers with a dichromat simulator were compared to those theoretically calculated from the color vision model used in the simulator.

Physical Ability-Task Performance Models: Assessing the Risk of Omitted Variable Bias

Science.gov (United States)

2008-09-15

association was evaluated in a study of simulated job performance in men and women. The study measured four major abilities, Static Strength (SS), Dynamic...ability- performance interface for physical tasks. Methods Sample Participants were active-duty naval personnel (64 men , 38 women) between ages 20...bench with feet flat on the floor. Position was adjusted so the bar was between the shoulder and nipple line. Handles were gripped at a comfortable

ON-Line Monitoring of Instrument Channel Performance: Volume 3: Applications to Nuclear Power Plant Technical Specification Instrumentation

Energy Technology Data Exchange (ETDEWEB)

E Davis, B Rasmussen

2004-12-31

This report is a guide for a technical specification change submittal and subsequent implementation of on-line monitoring for safety-related applications. This report is the third in a three-volume set. Volume 1, ''Guidelines for Model Development and Implementation'', presents the various tasks that must be completed to prepare models for and to implement an on-line monitoring system.

The BOLD Response during Stroop Task-Like Inhibition Paradigms: Effects of Task Difficulty and Task-Relevant Modality

Science.gov (United States)

Mitchell, Rachel L. C.

2005-01-01

Previous studies of the Stroop task propose two key mediators: the prefrontal and cingulate cortices but hints exist of functional specialization within these regions. This study aimed to examine the effect of task modality upon the prefrontal and cingulate response by examining the response to colour, number, and shape Stroop tasks whilst BOLD…

Computing for calculus

CERN Document Server

Christensen, Mark J

1981-01-01

Computing for Calculus focuses on BASIC as the computer language used for solving calculus problems.This book discusses the input statement for numeric variables, advanced intrinsic functions, numerical estimation of limits, and linear approximations and tangents. The elementary estimation of areas, numerical and string arrays, line drawing algorithms, and bisection and secant method are also elaborated. This text likewise covers the implicit functions and differentiation, upper and lower rectangular estimates, Simpson's rule and parabolic approximation, and interpolating polynomials. Other to

Holistic Processing in the Composite Task Depends on Face Size.

Science.gov (United States)

Ross, David A; Gauthier, Isabel

Holistic processing is a hallmark of face processing. There is evidence that holistic processing is strongest for faces at identification distance, 2 - 10 meters from the observer. However, this evidence is based on tasks that have been little used in the literature and that are indirect measures of holistic processing. We use the composite task- a well validated and frequently used paradigm - to measure the effect of viewing distance on holistic processing. In line with previous work, we find a congruency x alignment effect that is strongest for faces that are close (2m equivalent distance) than for faces that are further away (24m equivalent distance). In contrast, the alignment effect for same trials, used by several authors to measure holistic processing, produced results that are difficult to interpret. We conclude that our results converge with previous findings providing more direct evidence for an effect of size on holistic processing.

NOASYS, a system for on-line noise analysis

International Nuclear Information System (INIS)

Massier, H.

1978-07-01

This report describes NOASYS, a versatile NOise Analysis SYStem for digital on-line signal processing. The system based on a minicomputer, was originally developed for the analysis of noise signals from nuclear reactors. NOASYS computes various statistical functions e.g. cross- und auto-correlation functions and power spectral densities resp., which may be used for reactor diagnosis and malfunction detection. The system processes up to 16 analog signals with a maximum sampling frequency of 100 kcps (1 channel). The processing of the sampled data is done by a number of software tasks, which may be called from a teletype or linked together for specific measuring programs. The standard configuration contains the often used processing routines e.g. Fast Fourier Transform, complex multiplication, summation etc. In addition NOASYS may be extended by users own tasks (in Assembler or Fortran) to fit for specific applications. (orig.) 891 HP [de

The effect of ankle bracing on knee kinetics and kinematics during volleyball-specific tasks.

Science.gov (United States)

West, T; Ng, L; Campbell, A

2014-12-01

The purpose of this study was to examine the effects of ankle bracing on knee kinetics and kinematics during volleyball tasks. Fifteen healthy, elite, female volleyball players performed a series of straight-line and lateral volleyball tasks with no brace and when wearing an ankle brace. A 14-camera Vicon motion analysis system and AMTI force plate were used to capture the kinetic and kinematic data. Knee range of motion, peak knee anterior-posterior and medial-lateral shear forces, and peak ground reaction forces that occurred between initial contact with the force plate and toe off were compared using paired sample t-tests between the braced and non-braced conditions (P volleyball tasks. However, ankle bracing was demonstrated to reduce knee lateral shear forces during all of the lateral movement volleyball tasks. Wearing the Active Ankle T2 brace will not impact knee joint range of motion and may in fact reduce shear loading to the knee joint in volleyball players. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

An fMRI study of sex differences in regional activation to a verbal and a spatial task.

Science.gov (United States)

Gur, R C; Alsop, D; Glahn, D; Petty, R; Swanson, C L; Maldjian, J A; Turetsky, B I; Detre, J A; Gee, J; Gur, R E

2000-09-01

Sex differences in cognitive performance have been documented, women performing better on some phonological tasks and men on spatial tasks. An earlier fMRI study suggested sex differences in distributed brain activation during phonological processing, with bilateral activation seen in women while men showed primarily left-lateralized activation. This blood oxygen level-dependent fMRI study examined sex differences (14 men, 13 women) in activation for a spatial task (judgment of line orientation) compared to a verbal-reasoning task (analogies) that does not typically show sex differences. Task difficulty was manipulated. Hypothesized ROI-based analysis documented the expected left-lateralized changes for the verbal task in the inferior parietal and planum temporal regions in both men and women, but only men showed right-lateralized increase for the spatial task in these regions. Image-based analysis revealed a distributed network of cortical regions activated by the tasks, which consisted of the lateral frontal, medial frontal, mid-temporal, occipitoparietal, and occipital regions. The activation was more left lateralized for the verbal and more right for the spatial tasks, but men also showed some left activation for the spatial task, which was not seen in women. Increased task difficulty produced more distributed activation for the verbal and more circumscribed activation for the spatial task. The results suggest that failure to activate the appropriate hemisphere in regions directly involved in task performance may explain certain sex differences in performance. They also extend, for a spatial task, the principle that bilateral activation in a distributed cognitive system underlies sex differences in performance. Copyright 2000 Academic Press.

Simulating hemispatial neglect with virtual reality.

Science.gov (United States)

Baheux, Kenji; Yoshizawa, Makoto; Yoshida, Yasuko

2007-07-19

Hemispatial neglect is a cognitive disorder defined as a lack of attention for stimuli contra-lateral to the brain lesion. The assessment is traditionally done with basic pencil and paper tests and the rehabilitation programs are generally not well adapted. We propose a virtual reality system featuring an eye-tracking device for a better characterization of the neglect that will lead to new rehabilitation techniques. This paper presents a comparison of eye-gaze patterns of healthy subjects, patients and healthy simulated patients on a virtual line bisection test. The task was also executed with a reduced visual field condition hoping that fewer stimuli would limit the neglect. We found that patients and healthy simulated patients had similar eye-gaze patterns. However, while the reduced visual field condition had no effect on the healthy simulated patients, it actually had a negative impact on the patients. We discuss the reasons for these differences and how they relate to the limitations of the neglect simulation. We argue that with some improvements the technique could be used to determine the potential of new rehabilitation techniques and also help the rehabilitation staff or the patient's relatives to better understand the neglect condition.

Investigating Antecedents of Task Commitment and Task Attraction in Service Learning Team Projects

Science.gov (United States)

Schaffer, Bryan S.; Manegold, Jennifer G.

2018-01-01

The authors investigated the antecedents of team task cohesiveness in service learning classroom environments. Focusing on task commitment and task attraction as key dependent variables representing cohesiveness, and task interdependence as the primary independent variable, the authors position three important task action phase processes as…

78 FR 59939 - Meeting of the Community Preventive Services Task Force (Task Force)

Science.gov (United States)

2013-09-30

... Community Preventive Services Task Force (Task Force) AGENCY: Centers for Disease Control and Prevention... September 17, 2013, announcing the next meeting of the Community Preventive Services Task Force (Task Force... the Task Force to consider the findings of systematic reviews and issue findings and recommendations...

Cerebellar direct current stimulation enhances on-line motor skill acquisition through an effect on accuracy.

Science.gov (United States)

Cantarero, Gabriela; Spampinato, Danny; Reis, Janine; Ajagbe, Loni; Thompson, Tziporah; Kulkarni, Kopal; Celnik, Pablo

2015-02-18

The cerebellum is involved in the update of motor commands during error-dependent learning. Transcranial direct current stimulation (tDCS), a form of noninvasive brain stimulation, has been shown to increase cerebellar excitability and improve learning in motor adaptation tasks. Although cerebellar involvement has been clearly demonstrated in adaptation paradigms, a type of task that heavily relies on error-dependent motor learning mechanisms, its role during motor skill learning, a behavior that likely involves error-dependent as well as reinforcement and strategic mechanisms, is not completely understood. Here, in humans, we delivered cerebellar tDCS to modulate its activity during novel motor skill training over the course of 3 d and assessed gains during training (on-line effects), between days (off-line effects), and overall improvement. We found that excitatory anodal tDCS applied over the cerebellum increased skill learning relative to sham and cathodal tDCS specifically by increasing on-line rather than off-line learning. Moreover, the larger skill improvement in the anodal group was predominantly mediated by reductions in error rate rather than changes in movement time. These results have important implications for using cerebellar tDCS as an intervention to speed up motor skill acquisition and to improve motor skill accuracy, as well as to further our understanding of cerebellar function. Copyright © 2015 the authors 0270-6474/15/353285-06$15.00/0.

Sex differences in task distribution and task exposures among Danish house painters:

DEFF Research Database (Denmark)

Heilskov-Hansen, Thomas; Svendsen, Susanne Wulff; Thomsen, Jane Frølund

2014-01-01

OBJECTIVES: Sex differences in occupational biomechanical exposures may be part of the explanation why musculoskeletal complaints and disorders tend to be more common among women than among men. We aimed to determine possible sex differences in task distribution and task-specific postures...... correction were used to evaluate sex differences. RESULTS: Statistically significant (psex differences were revealed in task proportions, but the proportions differed by less than 4%. For task exposures, no statistically significant sex differences were found. CONCLUSIONS: Only minor sex differences...... and movements of the upper extremities among Danish house painters, and to establish sex-specific task exposure matrices. METHODS: To obtain task distributions, we sent out a questionnaire to all members of the Painters' Union in Denmark (N = 9364), of whom 53% responded. Respondents reported their task...

Effects of the cognitive tasks in the postural control of elderly: A systematic revision

Directory of Open Access Journals (Sweden)

Larissa Pires de Andrade

2011-09-01

Full Text Available Demanding attention in order to keep postural balance increases with aging and with the presence of concurrent tasks that require information processing. Several studies have demonstrated that motor performance can be related to the complexity of the task and aging process, presenting a possible interaction between these factors. The aim of this review was to identify and analyze published papers about the effects of cognitive tasks on the postural control of elderly individuals. A systematic search in the Web of Science, SportDiscus, CINAHL, Science Direct on line, Biological Abstracts, PsycINFO, and Medline databases was made and 444 articles were found. Eight were selected that studied the variables of interest. These studies showed that postural control seems to be influenced by the individual's attention processes and that deficits in such ability may be associated to an increased risk of falls.

Effects of the cognitive tasks in the postural control of elderly: A systematic revision

Directory of Open Access Journals (Sweden)

L.P. Andrade

2011-01-01

Full Text Available Demanding attention in order to keep postural balance increases with aging and with the presence of concurrent tasks that require information processing. Several studies have demonstrated that motor performance can be related to the complexity of the task and aging process, presenting a possible interaction between these factors. The aim of this review was to identify and analyze published papers about the effects of cognitive tasks on the postural control of elderly individuals. A systematic search in the Web of Science, SportDiscus, CINAHL, Science Direct on line, Biological Abstracts, PsycINFO, and Medline databases was made and 444 articles were found. Eight were selected that studied the variables of interest. These studies showed that postural control seems to be influenced by the individual's attention processes and that deficits in such ability may be associated to an increased risk of falls.

The Effect of a Workload-Preview on Task-Prioritization and Task-Performance

Science.gov (United States)

Minotra, Dev

2012-01-01

With increased volume and sophistication of cyber attacks in recent years, maintaining situation awareness and effective task-prioritization strategy is critical to the task of cybersecurity analysts. However, high levels of mental-workload associated with the task of cybersecurity analyst's limits their ability to prioritize tasks.…

Exploring relations between task conflict and informational conflict in the Stroop task.

Science.gov (United States)

Entel, Olga; Tzelgov, Joseph; Bereby-Meyer, Yoella; Shahar, Nitzan

2015-11-01

In this study, we tested the proposal that the Stroop task involves two conflicts--task conflict and informational conflict. Task conflict was defined as the latency difference between color words and non-letter neutrals, and manipulated by varying the proportion of color words versus non-letter neutrals. Informational conflict was defined as the latency difference between incongruent and congruent trials and manipulated by varying the congruent-to-incongruent trial ratio. We replicated previous findings showing that increasing the ratio of incongruent-to-congruent trials reduces the latency difference between the incongruent and congruent condition (i.e., informational conflict), as does increasing the proportion of color words (i.e., task conflict). A significant under-additive interaction between the two proportion manipulations (congruent vs. incongruent and color words vs. neutrals) indicated that the effects of task conflict and informational conflict were not additive. By assessing task conflict as the contrast between color words and neutrals, we found that task conflict existed in all of our experimental conditions. Under specific conditions, when task conflict dominated behavior by explaining most of the variability between congruency conditions, we also found negative facilitation, thus demonstrating that this effect is a special case of task conflict.

Investigating Perfect Timesharing: The Relationship between IM-Compatible Tasks and Dual-Task Performance

Science.gov (United States)

Halvorson, Kimberly M.; Ebner, Herschel; Hazeltine, Eliot

2013-01-01

Why are dual-task costs reduced with ideomotor (IM) compatible tasks (Greenwald & Shulman, 1973; Lien, Proctor & Allen, 2002)? In the present experiments, we first examine three different measures of single-task performance (pure single-task blocks, mixed blocks, and long stimulus onset asynchrony [SOA] trials in dual-task blocks) and two…

Microprocessor multi-task monitor

International Nuclear Information System (INIS)

Ludemann, C.A.

1983-01-01

This paper describes a multi-task monitor program for microprocessors. Although written for the Intel 8085, it incorporates features that would be beneficial for implementation in other microprocessors used in controlling and monitoring experiments and accelerators. The monitor places permanent programs (tasks) arbitrarily located throughout ROM in a priority ordered queue. The programmer is provided with the flexibility to add new tasks or modified versions of existing tasks, without having to comply with previously defined task boundaries or having to reprogram all of ROM. Scheduling of tasks is triggered by timers, outside stimuli (interrupts), or inter-task communications. Context switching time is of the order of tenths of a milllisecond

Hazardous Waste Cleanup: Unilever Bestfoods in Montville, New Jersey

Science.gov (United States)

Unilever Bestfoods area is approximately 27 acres and is bisected by Taylortown Road into eastern and western sections. Crooked Brook further bisects the western portion of the site into northern and southern sections in Montville, New Jersey.

A modular multi-microcomputer system for on-line vibration diagnostics

International Nuclear Information System (INIS)

Saedtler, E.

1988-01-01

A new modular multi-microprocessor system for on-line vibration monitoring and diagnostics of PWRs is described. The aim of the system is to make feasible an early detection of increasing failures in relevant regions of a reactor plant, to verify the mechanical integrity of the investigated components, and to improve therefore the operational safety of the plant. After a discussion of the implemented surveillance methods and algorithms, which are based on hierarchical structured identification (estimation) and statistical pattern recognition tools, the system architecture (software and hardware) is portrayed. The classification scheme itself works sequential so that samples (or features) can arrive on-line. This on-line classification is important in order to take necessary actions in time. Furthermore, the system has learning capabilities, which means it is adaptable to different, varying states and plant conditions. The main features of the system are presented and its contribution to an automation of complex surveillance and monitoring tasks is shown. (author)

Resilience and work-life balance in first-line nurse manager.

Science.gov (United States)

Kim, Miyoung; Windsor, Carol

2015-03-01

The aim of this study was to explore how first-line nurse managers constructed the meaning of resilience and its relationship to work-life balance for nurses in Korea. Participants were 20 first-line nurse managers working in six university hospitals. Data were collected through in-depth interviews from December 2011 to August 2012, and analyzed using Strauss and Corbin's grounded theory method. Analysis revealed that participants perceived work-life balance and resilience to be shaped by dynamic, reflective processes. The features consisting resilience included "positive thinking", "flexibility", "assuming responsibility", and "separating work and life". This perception of resilience has the potential to facilitate a shift in focus from negative to positive experiences, from rigidity to flexibility, from task-centered to person-centered thinking, and from the organization to life. Recognizing the importance of work-life balance in producing and sustaining resilience in first-line nurse managers could increase retention in the Korean nursing workforce. Copyright © 2015. Published by Elsevier B.V.

Strategic Adaptation to Task Characteristics, Incentives, and Individual Differences in Dual-Tasking.

Directory of Open Access Journals (Sweden)

Christian P Janssen

Full Text Available We investigate how good people are at multitasking by comparing behavior to a prediction of the optimal strategy for dividing attention between two concurrent tasks. In our experiment, 24 participants had to interleave entering digits on a keyboard with controlling a randomly moving cursor with a joystick. The difficulty of the tracking task was systematically varied as a within-subjects factor. Participants were also exposed to different explicit reward functions that varied the relative importance of the tracking task relative to the typing task (between-subjects. Results demonstrate that these changes in task characteristics and monetary incentives, together with individual differences in typing ability, influenced how participants choose to interleave tasks. This change in strategy then affected their performance on each task. A computational cognitive model was used to predict performance for a wide set of alternative strategies for how participants might have possibly interleaved tasks. This allowed for predictions of optimal performance to be derived, given the constraints placed on performance by the task and cognition. A comparison of human behavior with the predicted optimal strategy shows that participants behaved near optimally. Our findings have implications for the design and evaluation of technology for multitasking situations, as consideration should be given to the characteristics of the task, but also to how different users might use technology depending on their individual characteristics and their priorities.

78 FR 63208 - UPDATE-Meeting of the Community Preventive Services Task Force (Task Force)

Science.gov (United States)

2013-10-23

... of the Community Preventive Services Task Force (Task Force) AGENCY: Centers for Disease Control and... Community Preventive Services Task Force (Task Force). The in-person Task Force meeting is being replaced by... CDC's ability to complete the necessary scientific and logistical support for the meeting. The Task...

Properties of the ellipse-line-ellipse trajectory with asymmetrical variations

Science.gov (United States)

Guo, Zijia; Noo, Frédéric; Maier, Andreas; Lauritsch, Guenter

2016-03-01

Three-dimensional cone-beam (CB) imaging using a multi-axis floor-mounted (or ceiling-mounted) C-arm system has become an important tool in interventional radiology. This success motivates new developments to improve image quality. One direction in which advancement is sought is the data acquisition geometry and related CB artifacts. Currently, data acquisition is performed using the circular short-scan trajectory, which yields limited axial coverage and also provides incomplete data for accurate reconstruction. To improve the image quality, as well as to increase the coverage in the longitudinal direction of the patient, we recently introduced the ellipse- line-ellipse trajectory and showed that this trajectory provides full R-line coverage within the field-of-view, which is a key property for accurate reconstruction from truncated data. An R-line is any segment of line that connects two source positions. Here, we examine how the application of asymmetrical variations to the definition of the ELE trajectory impacts the R-line coverage. This question is significant to understand how much flexibility can be used in the implementation of the ELE trajectory, particularly to adapt the scan to patient anatomy and imaging task of interest. Two types of asymmetrical variations, called axial and angular variations, are investigated.

Some schemes for on-line correction of the closed orbit, dispersion and beta functions in PEP

International Nuclear Information System (INIS)

Donald, M.H.R.; Blocker, C.; Chao, A.W.; Hollebeek, R.J.; Lee, M.J.; Linstadt, J.E.; Siegrist, J.L.; Spencer, N.

1981-02-01

PEP has been operated successfully under computer control. It is necessary for colliding beam operation that the errors in closed orbits, dispersion and beta functions be corrected. The schemes in the PEP control program for on-line correction of these errors are described in this paper. The orbit control tasks in the PEP control system perform the functions of data gathering, data presentation (color display, printing), calculation and setting of corrector magnets. The tasks are generally small and modular, taking information from the database, processing it, then returning the results to the database. The PEP operator communicates with the tasks through touch panels monitored by the Director program. The display task, which displays orbit and corrector information on a TV color display, provides the main information required by the operator

Involvement of the Left Supramarginal Gyrus in Manipulation Judgment Tasks: Contributions to Theories of Tool Use.

Science.gov (United States)

Lesourd, Mathieu; Osiurak, François; Navarro, Jordan; Reynaud, Emanuelle

2017-09-01

Two theories of tool use, namely the gesture engram and the technical reasoning theories, make distinct predictions about the involvement of the left inferior parietal lobe (IPL) in manipulation judgement tasks. The objective here is to test these alternative predictions based on previous studies on manipulation judgment tasks using transcranial magnetic stimulations (TMS) targeting the left supramarginal gyrus (SMG). We review recent TMS studies on manipulation judgement tasks and confront these data with predictions made by both tool use theories. The left SMG is a highly intertwined region, organized following several functionally distinct areas and TMS may have disrupted a cortical network involved in the ability to use tools rather than only one functional area supporting manipulation knowledge. Moreover, manipulation judgement tasks may be impaired following virtual lesions outside the IPL. These data are more in line with the technical reasoning hypothesis, which assumes that the left IPL does not store manipulation knowledge per se. (JINS, 2017, 23, 685-691).

Influence of time pressure in a simple response task, a choice-by-location task, and the Simon task

NARCIS (Netherlands)

van der Lubbe, Robert Henricus Johannes; Jaśkowski, Piotr; Wauschkuhn, Bernd; Verleger, Rolf

2001-01-01

Examined the influence of strategy for a simple response task, a choice-by-location task, and the Simon task by varying time pressure in 11 Ss (mean age 28 yrs). Besides reaction time (RT) and accuracy, we measured response force and derived two measures from the event-related EEG potential to form

Task complexity, student perceptions of vocabulary learning in EFL, and task performance.

Science.gov (United States)

Wu, Xiaoli; Lowyck, Joost; Sercu, Lies; Elen, Jan

2013-03-01

The study deepened our understanding of how students' self-efficacy beliefs contribute to the context of teaching English as a foreign language in the framework of cognitive mediational paradigm at a fine-tuned task-specific level. The aim was to examine the relationship among task complexity, self-efficacy beliefs, domain-related prior knowledge, learning strategy use, and task performance as they were applied to English vocabulary learning from reading tasks. Participants were 120 second-year university students (mean age 21) from a Chinese university. This experiment had two conditions (simple/complex). A vocabulary level test was first conducted to measure participants' prior knowledge of English vocabulary. Participants were then randomly assigned to one of the learning tasks. Participants were administered task booklets together with the self-efficacy scales, measures of learning strategy use, and post-tests. Data obtained were submitted to multivariate analysis of variance (MANOVA) and path analysis. Results from the MANOVA model showed a significant effect of vocabulary level on self-efficacy beliefs, learning strategy use, and task performance. Task complexity showed no significant effect; however, an interaction effect between vocabulary level and task complexity emerged. Results from the path analysis showed self-efficacy beliefs had an indirect effect on performance. Our results highlighted the mediating role of self-efficacy beliefs and learning strategy use. Our findings indicate that students' prior knowledge plays a crucial role on both self-efficacy beliefs and task performance, and the predictive power of self-efficacy on task performance may lie in its association with learning strategy use. © 2011 The British Psychological Society.

The functional neuroanatomy of multitasking: combining dual tasking with a short term memory task.

Science.gov (United States)

Deprez, Sabine; Vandenbulcke, Mathieu; Peeters, Ron; Emsell, Louise; Amant, Frederic; Sunaert, Stefan

2013-09-01

Insight into the neural architecture of multitasking is crucial when investigating the pathophysiology of multitasking deficits in clinical populations. Presently, little is known about how the brain combines dual-tasking with a concurrent short-term memory task, despite the relevance of this mental operation in daily life and the frequency of complaints related to this process, in disease. In this study we aimed to examine how the brain responds when a memory task is added to dual-tasking. Thirty-three right-handed healthy volunteers (20 females, mean age 39.9 ± 5.8) were examined with functional brain imaging (fMRI). The paradigm consisted of two cross-modal single tasks (a visual and auditory temporal same-different task with short delay), a dual-task combining both single tasks simultaneously and a multi-task condition, combining the dual-task with an additional short-term memory task (temporal same-different visual task with long delay). Dual-tasking compared to both individual visual and auditory single tasks activated a predominantly right-sided fronto-parietal network and the cerebellum. When adding the additional short-term memory task, a larger and more bilateral frontoparietal network was recruited. We found enhanced activity during multitasking in components of the network that were already involved in dual-tasking, suggesting increased working memory demands, as well as recruitment of multitask-specific components including areas that are likely to be involved in online holding of visual stimuli in short-term memory such as occipito-temporal cortex. These results confirm concurrent neural processing of a visual short-term memory task during dual-tasking and provide evidence for an effective fMRI multitasking paradigm. © 2013 Elsevier Ltd. All rights reserved.

Quantitative assessment of motor functions post-stroke: Responsiveness of upper-extremity robotic measures and its task dependence.

Science.gov (United States)

Hussain, Asif; Budhota, Aamani; Contu, Sara; Kager, Simone; Vishwanath, Deshmukh A; Kuah, Christopher W K; Yam, Lester H L; Chua, Karen S G; Masia, Lorenzo; Campolo, Domenico

2017-07-01

Technology aided measures offer a sensitive, accurate and time-efflcient approach for the assessment of sensorimotor function after neurological impairment compared to standard clinical assessments. This preliminary study investigated the relationship between task definition and its effect on robotic measures using a planar, two degree of freedom, robotic-manipulator (H-Man). Four chronic stroke participants (49.5±11.95 years, 2 Female, FMA: 37.5±13.96) and eight healthy control participants (26.25± 4.70 years, 2 Female) participated in the study. Motor functions were evaluated using line tracing and circle tracing tasks with dominant and nondominant hand of healthy and affected vs. non affected hand of stroke participants. The results show significant dependence of quantitative measures on investigated tasks.

Regeneration in bipinnaria larvae of the bat star Patiria miniata induces rapid and broad new gene expression.

Science.gov (United States)

Oulhen, Nathalie; Heyland, Andreas; Carrier, Tyler J; Zazueta-Novoa, Vanesa; Fresques, Tara; Laird, Jessica; Onorato, Thomas M; Janies, Daniel; Wessel, Gary

2016-11-01

Some metazoa have the capacity to regenerate lost body parts. This phenomenon in adults has been classically described in echinoderms, especially in sea stars (Asteroidea). Sea star bipinnaria larvae can also rapidly and effectively regenerate a complete larva after surgical bisection. Understanding the capacity to reverse cell fates in the larva is important from both a developmental and biomedical perspective; yet, the mechanisms underlying regeneration in echinoderms are poorly understood. Here, we describe the process of bipinnaria regeneration after bisection in the bat star Patiria miniata. We tested transcriptional, translational, and cell proliferation activity after bisection in anterior and posterior bipinnaria halves as well as expression of SRAP, reported as a sea star regeneration associated protease (Vickery et al., 2001b). Moreover, we found several genes whose transcripts increased in abundance following bisection, including: Vasa, dysferlin, vitellogenin 1 and vitellogenin 2. These results show a transformation following bisection, especially in the anterior halves, of cell fate reassignment in all three germ layers, with clear and predictable changes. These results define molecular events that accompany the cell fate changes coincident to the regenerative response in echinoderm larvae. Crown Copyright © 2016. Published by Elsevier Ireland Ltd. All rights reserved.

Correlates of academic procrastination: discomfort, task aversiveness, and task capability.

Science.gov (United States)

Milgram, N; Marshevsky, S; Sadeh, C

1995-03-01

The relationships among five aspects of academic procrastination--behavioral delay, personal upset about the delay, task aversiveness, task capability, and the desire to reduce behavioral delay--were investigated in 10th-grade Israeli students (N = 195). Upset about delay was weakly related to delay itself, and--unlike delay--was strongly related to perceived capability to perform academic tasks and to the desire to change delaying behavior. Students delayed more on academic tasks labeled unpleasant than pleasant, were neutral in between, and were correspondingly more upset about the former than the latter. They more frequently acknowledged reasons for academic procrastination that were less threatening to their self-image (e.g., problems in time management) than reasons that were more threatening (e.g., lack of ability). Interest in reducing delay is related more to self-perceived ability to handle tasks than to time spent procrastinating or reasons given for procrastinating.

Oracle Enterprise Manager 12c command-line interface

CERN Document Server

Pot'Vin, Kellyn; Smith, Ray

2014-01-01

Oracle Enterprise Manager 12c Command-Line Interface shows how to use Enterprise Manager's powerful scripting language to automate your database administration work and save time by scripting routine tasks, and then executing those scripts across collections of databases and instances in your environment. This book is chock full of ready-made scripting examples contributed by the authors and leading members of the community. For example, you'll find scripts and examples of commands to: Remove an Enterprise Manager agent and its related targetsQuickly create administrator accounts that are ful

Task related doses in Spanish pressurized water reactors over the period 1988-1992

Energy Technology Data Exchange (ETDEWEB)

O`Donnell, P.; Labarta, T.; Amor, I. [Subdireccion de Proteccion Radiologica, Madrid (Spain)

1995-03-01

In order to evaluate in depth the collective dose trend and its correlation with the effectiveness of the practical application of the ALARA principle in Spanish nuclear facilities, and base the different policy lines to promote this criteria, the CSN has fullfilled an analysis of the task related doses data over the period 1988-1992. Previously, the CSN had required to the utilities the compilation of their refuelling outage collective dose from 1988 according with a predeterminate number of tasks, in order to have available a representative and retrospective set of data in an homogeneous way and coherent with the international data banks on occupational exposure in NPP, as the CEC and the NEA ones. The scope of this analysis was the following: first, the collective dose summaries for outage tasks and departments for PWR and for BWR, including the minimum, maximum and average dose (and statistics data) for 18 different refuelling outage tasks and 12 personal departments for each generation of each type of rector, the task and department related collective dose trends in each plant and in each generation, and second, the dose reduction techniques having been used during that period in each plant and the relative level of adoption. In this presentation the main results and conclusions of the first part of the study are reviewed for PWR.

"Photographing money" task pricing

Science.gov (United States)

Jia, Zhongxiang

2018-05-01

"Photographing money" [1]is a self-service model under the mobile Internet. The task pricing is reasonable, related to the success of the commodity inspection. First of all, we analyzed the position of the mission and the membership, and introduced the factor of membership density, considering the influence of the number of members around the mission on the pricing. Multivariate regression of task location and membership density using MATLAB to establish the mathematical model of task pricing. At the same time, we can see from the life experience that membership reputation and the intensity of the task will also affect the pricing, and the data of the task success point is more reliable. Therefore, the successful point of the task is selected, and its reputation, task density, membership density and Multiple regression of task positions, according to which a nhew task pricing program. Finally, an objective evaluation is given of the advantages and disadvantages of the established model and solution method, and the improved method is pointed out.

Individual differences in first- and second-order temporal judgment.

Science.gov (United States)

Corcoran, Andrew W; Groot, Christopher; Bruno, Aurelio; Johnston, Alan; Cropper, Simon J

2018-01-01

The ability of subjects to identify and reproduce brief temporal intervals is influenced by many factors whether they be stimulus-based, task-based or subject-based. The current study examines the role individual differences play in subsecond and suprasecond timing judgments, using the schizoptypy personality scale as a test-case approach for quantifying a broad range of individual differences. In two experiments, 129 (Experiment 1) and 141 (Experiment 2) subjects completed the O-LIFE personality questionnaire prior to performing a modified temporal-bisection task. In the bisection task, subjects responded to two identical instantiations of a luminance grating presented in a 4deg window, 4deg above fixation for 1.5 s (Experiment 1) or 3 s (Experiment 2). Subjects initiated presentation with a button-press, and released the button when they considered the stimulus to be half-way through (750/1500 ms). Subjects were then asked to indicate their 'most accurate estimate' of the two intervals. In this way we measure both performance on the task (a first-order measure) and the subjects' knowledge of their performance (a second-order measure). In Experiment 1 the effect of grating-drift and feedback on performance was also examined. Experiment 2 focused on the static/no-feedback condition. For the group data, Experiment 1 showed a significant effect of presentation order in the baseline condition (no feedback), which disappeared when feedback was provided. Moving the stimulus had no effect on perceived duration. Experiment 2 showed no effect of stimulus presentation order. This elimination of the subsecond order-effect was at the expense of accuracy, as the mid-point of the suprasecond interval was generally underestimated. Response precision increased as a proportion of total duration, reducing the variance below that predicted by Weber's law. This result is consistent with a breakdown of the scalar properties of time perception in the early suprasecond range. All

Time Resolved Spectrometry on the Test Beam Line at CTF3

CERN Document Server

Olvegård, M; Lefèvre, T; Döbert, S; Adli, E

2009-01-01

The CTF3 provides a high current (28 A) high frequency (12 GHz) electron beam, which is used to generate high power radiofrequency pulses at 12 GHz by decelerating the electrons in resonant structures. A Test Beam Line (TBL) is currently being built in order to prove the efficiency and the reliability of the RF power production with the lowest level of particle losses. As the beam propagates along the line, its energy spread grows up to 60%. For instrumentation, this unusual characteristic implies the development of new and innovative techniques. One of the most important tasks is to measure the beam energy spread with a fast time resolution. The detector must be able to detect the energy transient due to beam loading in the decelerating structures (nanosecond) but should also be capable to measure bunch-to-bunch fluctuations (12 GHz). This paper presents the design of the spectrometer line detectors.

Board Task Performance

DEFF Research Database (Denmark)

Minichilli, Alessandro; Zattoni, Alessandro; Nielsen, Sabina

2012-01-01

identify three board processes as micro-level determinants of board effectiveness. Specifically, we focus on effort norms, cognitive conflicts and the use of knowledge and skills as determinants of board control and advisory task performance. Further, we consider how two different institutional settings....... The findings show that: (i) Board processes have a larger potential than demographic variables to explain board task performance; (ii) board task performance differs significantly between boards operating in different contexts; and (iii) national context moderates the relationships between board processes...... and board task performance....

An on-line data acquisition system based on Norsk-Data ND-560 computer

International Nuclear Information System (INIS)

Bandyopadhyay, A.; Roy, A.; Dey, S.K.; Bhattacharya, S.; Bhowmik, R.K.

1987-01-01

This paper describes a high-speed data acquisition system based on CAMAC for Norsk Data ND-560 computer operating in a multiuser environment. As opposed to the present trend, the system has been implemented with minimum hardware at CAMAC level taking advantage of the dual processors of ND-560. The package consists of several coordinated tasks running in the two CPUs which acquire data, record on tape, permit on-line analysis and display the data and perform related control operations. It has been used in several experiments at VECC and its performance in on-line experiments is reported. (orig.)

Perception while watching movies: Effects of physical screen size and scene type.

Science.gov (United States)

Troscianko, Tom; Meese, Timothy S; Hinde, Stephen

2012-01-01

Over the last decade, television screens and display monitors have increased in size considerably, but has this improved our televisual experience? Our working hypothesis was that the audiences adopt a general strategy that "bigger is better." However, as our visual perceptions do not tap directly into basic retinal image properties such as retinal image size (C. A. Burbeck, 1987), we wondered whether object size itself might be an important factor. To test this, we needed a task that would tap into the subjective experiences of participants watching a movie on different-sized displays with the same retinal subtense. Our participants used a line bisection task to self-report their level of "presence" (i.e., their involvement with the movie) at several target locations that were probed in a 45-min section of the movie "The Good, The Bad, and The Ugly." Measures of pupil dilation and reaction time to the probes were also obtained. In Experiment 1, we found that subjective ratings of presence increased with physical screen size, supporting our hypothesis. Face scenes also produced higher presence scores than landscape scenes for both screen sizes. In Experiment 2, reaction time and pupil dilation results showed the same trends as the presence ratings and pupil dilation correlated with presence ratings, providing some validation of the method. Overall, the results suggest that real-time measures of subjective presence might be a valuable tool for measuring audience experience for different types of (i) display and (ii) audiovisual material.

IDEN2-A program for visual identification of spectral lines and energy levels in optical spectra of atoms and simple molecules

Science.gov (United States)

Azarov, V. I.; Kramida, A.; Vokhmentsev, M. Ya.

2018-04-01

The article describes a Java program that can be used in a user-friendly way to visually identify spectral lines observed in complex spectra with theoretically predicted transitions between atomic or molecular energy levels. The program arranges various information about spectral lines and energy levels in such a way that line identification and determination of positions of experimentally observed energy levels become much easier tasks that can be solved fast and efficiently.

A new semantic vigilance task: vigilance decrement, workload, and sensitivity to dual-task costs.

Science.gov (United States)

Epling, Samantha L; Russell, Paul N; Helton, William S

2016-01-01

Cognitive resource theory is a common explanation for both the performance decline in vigilance tasks, known as the vigilance decrement, and the limited ability to perform multiple tasks simultaneously. The limited supply of cognitive resources may be utilized faster than they are replenished resulting in a performance decrement, or may need to be allocated among multiple tasks with some performance cost. Researchers have proposed both domain-specific, for example spatial versus verbal processing resources, and domain general cognitive resources. One challenge in testing the domain specificity of cognitive resources in vigilance is the current lack of difficult semantic vigilance tasks which reliably produce a decrement. In the present research, we investigated whether the vigilance decrement was found in a new abbreviated semantic discrimination vigilance task, and whether there was a performance decrement in said vigilance task when paired with a word recall task, as opposed to performed individually. As hypothesized, a vigilance decrement in the semantic vigilance task was found in both the single-task and dual-task conditions, along with reduced vigilance performance in the dual-task condition and reduced word recall in the dual-task condition. This is consistent with cognitive resource theory. The abbreviated semantic vigilance task will be a useful tool for researchers interested in determining the specificity of cognitive resources utilized in vigilance tasks.

Mood states determine the degree of task shielding in dual-task performance.

Science.gov (United States)

Zwosta, Katharina; Hommel, Bernhard; Goschke, Thomas; Fischer, Rico

2013-01-01

Current models of multitasking assume that dual-task performance and the degree of multitasking are affected by cognitive control strategies. In particular, cognitive control is assumed to regulate the amount of shielding of the prioritised task from crosstalk from the secondary task. We investigated whether and how task shielding is influenced by mood states. Participants were exposed to two short film clips, one inducing high and one inducing low arousal, of either negative or positive content. Negative mood led to stronger shielding of the prioritised task (i.e., less crosstalk) than positive mood, irrespective of arousal. These findings support the assumption that emotional states determine the parameters of cognitive control and play an important role in regulating dual-task performance.

Brain activations during bimodal dual tasks depend on the nature and combination of component tasks

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Emma eSalo

2015-02-01

Full Text Available We used functional magnetic resonance imaging to investigate brain activations during nine different dual tasks in which the participants were required to simultaneously attend to concurrent streams of spoken syllables and written letters. They performed a phonological, spatial or simple (speaker-gender or font-shade discrimination task within each modality. We expected to find activations associated specifically with dual tasking especially in the frontal and parietal cortices. However, no brain areas showed systematic dual task enhancements common for all dual tasks. Further analysis revealed that dual tasks including component tasks that were according to Baddeley’s model modality atypical, that is, the auditory spatial task or the visual phonological task, were not associated with enhanced frontal activity. In contrast, for other dual tasks, activity specifically associated with dual tasking was found in the left or bilateral frontal cortices. Enhanced activation in parietal areas, however, appeared not to be specifically associated with dual tasking per se, but rather with intermodal attention switching. We also expected effects of dual tasking in left frontal supramodal phonological processing areas when both component tasks required phonological processing and in right parietal supramodal spatial processing areas when both tasks required spatial processing. However, no such effects were found during these dual tasks compared with their component tasks performed separately. Taken together, the current results indicate that activations during dual tasks depend in a complex manner on specific demands of component tasks.

The predictive value of general movement tasks in assessing occupational task performance.

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Frost, David M; Beach, Tyson A C; McGill, Stuart M; Callaghan, Jack P

2015-01-01

Within the context of evaluating individuals' movement behavior it is generally assumed that the tasks chosen will predict their competency to perform activities relevant to their occupation. This study sought to examine whether a battery of general tasks could be used to predict the movement patterns employed by firefighters to perform select job-specific skills. Fifty-two firefighters performed a battery of general and occupation-specific tasks that simulated the demands of firefighting. Participants' peak lumbar spine and frontal plane knee motion were compared across tasks. During 85% of all comparisons, the magnitude of spine and knee motion was greater during the general movement tasks than observed during the firefighting skills. Certain features of a worker's movement behavior may be exhibited across a range of tasks. Therefore, provided that a movement screen's tasks expose the motions of relevance for the population being tested, general evaluations could offer valuable insight into workers' movement competency or facilitate an opportunity to establish an evidence-informed intervention.

Medical Care Tasks among Spousal Dementia Caregivers: Links to Care-Related Sleep Disturbances.

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Polenick, Courtney A; Leggett, Amanda N; Maust, Donovan T; Kales, Helen C

2018-05-01

Medical care tasks are commonly provided by spouses caring for persons living with dementia (PLWDs). These tasks reflect complex care demands that may interfere with sleep, yet their implications for caregivers' sleep outcomes are unknown. The authors evaluated the association between caregivers' medical/nursing tasks (keeping track of medications; managing tasks such as ostomy care, intravenous lines, or blood testing; giving shots/injections; and caring for skin wounds/sores) and care-related sleep disturbances. A retrospective analysis of cross-sectional data from the 2011 National Health and Aging Trends Study and National Study of Caregiving was conducted. Spousal caregivers and PLWDs/proxies were interviewed by telephone at home. The U.S. sample included 104 community-dwelling spousal caregivers and PLWDs. Caregivers reported on their sociodemographic and health characteristics, caregiving stressors, negative caregiving relationship quality, and sleep disturbances. PLWDs (or proxies) reported on their health conditions and sleep problems. Caregivers who performed a higher number of medical/nursing tasks reported significantly more frequent care-related sleep disturbances, controlling for sociodemographic and health characteristics, caregiving stressors, negative caregiving relationship quality, and PLWDs' sleep problems and health conditions. Post hoc tests showed that wound care was independently associated with more frequent care-related sleep disturbances after accounting for the other medical/nursing tasks and covariates. Spousal caregivers of PLWDs who perform medical/nursing tasks may be at heightened risk for sleep disturbances and associated adverse health consequences. Interventions to promote the well-being of both care partners may benefit from directly addressing caregivers' needs and concerns about their provision of medical/nursing care. Copyright © 2018 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights

Task conflict and proactive control: A computational theory of the Stroop task.

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Kalanthroff, Eyal; Davelaar, Eddy J; Henik, Avishai; Goldfarb, Liat; Usher, Marius

2018-01-01

The Stroop task is a central experimental paradigm used to probe cognitive control by measuring the ability of participants to selectively attend to task-relevant information and inhibit automatic task-irrelevant responses. Research has revealed variability in both experimental manipulations and individual differences. Here, we focus on a particular source of Stroop variability, the reverse-facilitation (RF; faster responses to nonword neutral stimuli than to congruent stimuli), which has recently been suggested as a signature of task conflict. We first review the literature that shows RF variability in the Stroop task, both with regard to experimental manipulations and to individual differences. We suggest that task conflict variability can be understood as resulting from the degree of proactive control that subjects recruit in advance of the Stroop stimulus. When the proactive control is high, task conflict does not arise (or is resolved very quickly), resulting in regular Stroop facilitation. When proactive control is low, task conflict emerges, leading to a slow-down in congruent and incongruent (but not in neutral) trials and thus to Stroop RF. To support this suggestion, we present a computational model of the Stroop task, which includes the resolution of task conflict and its modulation by proactive control. Results show that our model (a) accounts for the variability in Stroop-RF reported in the experimental literature, and (b) solves a challenge to previous Stroop models-their ability to account for reaction time distributional properties. Finally, we discuss theoretical implications to Stroop measures and control deficits observed in some psychopathologies. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Planning and task management in Parkinson's disease: differential emphasis in dual-task performance.

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Bialystok, Ellen; Craik, Fergus I M; Stefurak, Taresa

2008-03-01

Seventeen patients diagnosed with Parkinson's disease completed a complex computer-based task that involved planning and management while also performing an attention-demanding secondary task. The tasks were performed concurrently, but it was necessary to switch from one to the other. Performance was compared to a group of healthy age-matched control participants and a group of young participants. Parkinson's patients performed better than the age-matched controls on almost all measures and as well as the young controls in many cases. However, the Parkinson's patients achieved this by paying relatively less attention to the secondary task and focusing attention more on the primary task. Thus, Parkinson's patients can apparently improve their performance on some aspects of a multidimensional task by simplifying task demands. This benefit may occur as a consequence of their inflexible exaggerated attention to some aspects of a complex task to the relative neglect of other aspects.

The Applicability of Rhythm-Motor Tasks to a New Dual Task Paradigm for Older Adults

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Soo Ji Kim

2017-12-01

Full Text Available Given the interplay between cognitive and motor functions during walking, cognitive demands required during gait have been investigated with regard to dual task performance. Along with the needs to understand how the type of concurrent task while walking affects gait performance, there are calls for diversified dual tasks that can be applied to older adults with varying levels of cognitive decline. Therefore, this study aimed to examine how rhythm-motor tasks affect dual task performance and gait control, compared to a traditional cognitive-motor task. Also, it examined whether rhythm-motor tasks are correlated with traditional cognitive-motor task performance and cognitive measures. Eighteen older adults without cognitive impairment participated in this study. Each participant was instructed to walk at self-paced tempo without performing a concurrent task (single walking task and walk while separately performing two types of concurrent tasks: rhythm-motor and cognitive-motor tasks. Rhythm-motor tasks included instrument playing (WalkIP, matching to rhythmic cueing (WalkRC, and instrument playing while matching to rhythmic cueing (WalkIP+RC. The cognitive-motor task involved counting forward by 3s (WalkCount.f3. In each condition, dual task costs (DTC, a measure for how dual tasks affect gait parameters, were measured in terms of walking speed and stride length. The ratio of stride length to walking speed, a measure for dynamic control of gait, was also examined. The results of this study demonstrated that the task type was found to significantly influence these measures. Rhythm-motor tasks were found to interfere with gait parameters to a lesser extent than the cognitive-motor task (WalkCount.f3. In terms of ratio measures, stride length remained at a similar level, walking speed greatly decreased in the WalkCount.f3 condition. Significant correlations between dual task-related measures during rhythm-motor and cognitive-motor tasks support the

Single-task and dual-task tandem gait test performance after concussion.

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Howell, David R; Osternig, Louis R; Chou, Li-Shan

2017-07-01

To compare single-task and dual-task tandem gait test performance between athletes after concussion with controls on observer-timed, spatio-temporal, and center-of-mass (COM) balance control measurements. Ten participants (19.0±5.5years) were prospectively identified and completed a tandem gait test protocol within 72h of concussion and again 1 week, 2 weeks, 1 month, and 2 months post-injury. Seven uninjured controls (20.0±4.5years) completed the same protocol in similar time increments. Tandem gait test trials were performed with (dual-task) and without (single-task) concurrently performing a cognitive test as whole-body motion analysis was performed. Outcome variables included test completion time, average tandem gait velocity, cadence, and whole-body COM frontal plane displacement. Concussion participants took significantly longer to complete the dual-task tandem gait test than controls throughout the first 2 weeks post-injury (mean time=16.4 [95% CI: 13.4-19.4] vs. 10.1 [95% CI: 6.4-13.7] seconds; p=0.03). Single-task tandem gait times were significantly lower 72h post-injury (p=0.04). Dual-task cadence was significantly lower for concussion participants than controls (89.5 [95% CI: 68.6-110.4] vs. 127.0 [95% CI: 97.4-156.6] steps/minute; p=0.04). Moderately-high to high correlations between tandem gait test time and whole-body COM medial-lateral displacement were detected at each time point during dual-task gait (r s =0.70-0.93; p=0.03-0.001). Adding a cognitive task during the tandem gait test resulted in longer detectable deficits post-concussion compared to the traditional single-task tandem gait test. As a clinical tool to assess dynamic motor function, tandem gait may assist with return to sport decisions after concussion. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Optimal task mapping in safety-critical real-time parallel systems

International Nuclear Information System (INIS)

Aussagues, Ch.

1998-01-01

This PhD thesis is dealing with the correct design of safety-critical real-time parallel systems. Such systems constitutes a fundamental part of high-performance systems for command and control that can be found in the nuclear domain or more generally in parallel embedded systems. The verification of their temporal correctness is the core of this thesis. our contribution is mainly in the following three points: the analysis and extension of a programming model for such real-time parallel systems; the proposal of an original method based on a new operator of synchronized product of state machines task-graphs; the validation of the approach by its implementation and evaluation. The work addresses particularly the main problem of optimal task mapping on a parallel architecture, such that the temporal constraints are globally guaranteed, i.e. the timeliness property is valid. The results incorporate also optimally criteria for the sizing and correct dimensioning of a parallel system, for instance in the number of processing elements. These criteria are connected with operational constraints of the application domain. Our approach is based on the off-line analysis of the feasibility of the deadline-driven dynamic scheduling that is used to schedule tasks inside one processor. This leads us to define the synchronized-product, a system of linear, constraints is automatically generated and then allows to calculate a maximum load of a group of tasks and then to verify their timeliness constraints. The communications, their timeliness verification and incorporation to the mapping problem is the second main contribution of this thesis. FInally, the global solving technique dealing with both task and communication aspects has been implemented and evaluated in the framework of the OASIS project in the LETI research center at the CEA/Saclay. (author)

16p11.2 Deletion Mice Display Cognitive Deficits in Touchscreen Learning and Novelty Recognition Tasks

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Yang, Mu; Lewis, Freeman C.; Sarvi, Michael S.; Foley, Gillian M.; Crawley, Jacqueline N.

2015-01-01

Chromosomal 16p11.2 deletion syndrome frequently presents with intellectual disabilities, speech delays, and autism. Here we investigated the Dolmetsch line of 16p11.2 heterozygous (+/-) mice on a range of cognitive tasks with different neuroanatomical substrates. Robust novel object recognition deficits were replicated in two cohorts of 16p11.2…

On the importance of Task 1 and error performance measures in PRP dual-task studies

Science.gov (United States)

Strobach, Tilo; Schütz, Anja; Schubert, Torsten

2015-01-01

The psychological refractory period (PRP) paradigm is a dominant research tool in the literature on dual-task performance. In this paradigm a first and second component task (i.e., Task 1 and Task 2) are presented with variable stimulus onset asynchronies (SOAs) and priority to perform Task 1. The main indicator of dual-task impairment in PRP situations is an increasing Task 2-RT with decreasing SOAs. This impairment is typically explained with some task components being processed strictly sequentially in the context of the prominent central bottleneck theory. This assumption could implicitly suggest that processes of Task 1 are unaffected by Task 2 and bottleneck processing, i.e., decreasing SOAs do not increase reaction times (RTs) and error rates of the first task. The aim of the present review is to assess whether PRP dual-task studies included both RT and error data presentations and statistical analyses and whether studies including both data types (i.e., RTs and error rates) show data consistent with this assumption (i.e., decreasing SOAs and unaffected RTs and/or error rates in Task 1). This review demonstrates that, in contrast to RT presentations and analyses, error data is underrepresented in a substantial number of studies. Furthermore, a substantial number of studies with RT and error data showed a statistically significant impairment of Task 1 performance with decreasing SOA. Thus, these studies produced data that is not primarily consistent with the strong assumption that processes of Task 1 are unaffected by Task 2 and bottleneck processing in the context of PRP dual-task situations; this calls for a more careful report and analysis of Task 1 performance in PRP studies and for a more careful consideration of theories proposing additions to the bottleneck assumption, which are sufficiently general to explain Task 1 and Task 2 effects. PMID:25904890

On the importance of Task 1 and error performance measures in PRP dual-task studies.

Science.gov (United States)

Strobach, Tilo; Schütz, Anja; Schubert, Torsten

2015-01-01

The psychological refractory period (PRP) paradigm is a dominant research tool in the literature on dual-task performance. In this paradigm a first and second component task (i.e., Task 1 and Task 2) are presented with variable stimulus onset asynchronies (SOAs) and priority to perform Task 1. The main indicator of dual-task impairment in PRP situations is an increasing Task 2-RT with decreasing SOAs. This impairment is typically explained with some task components being processed strictly sequentially in the context of the prominent central bottleneck theory. This assumption could implicitly suggest that processes of Task 1 are unaffected by Task 2 and bottleneck processing, i.e., decreasing SOAs do not increase reaction times (RTs) and error rates of the first task. The aim of the present review is to assess whether PRP dual-task studies included both RT and error data presentations and statistical analyses and whether studies including both data types (i.e., RTs and error rates) show data consistent with this assumption (i.e., decreasing SOAs and unaffected RTs and/or error rates in Task 1). This review demonstrates that, in contrast to RT presentations and analyses, error data is underrepresented in a substantial number of studies. Furthermore, a substantial number of studies with RT and error data showed a statistically significant impairment of Task 1 performance with decreasing SOA. Thus, these studies produced data that is not primarily consistent with the strong assumption that processes of Task 1 are unaffected by Task 2 and bottleneck processing in the context of PRP dual-task situations; this calls for a more careful report and analysis of Task 1 performance in PRP studies and for a more careful consideration of theories proposing additions to the bottleneck assumption, which are sufficiently general to explain Task 1 and Task 2 effects.

Developing an expert system to control a beam line at the Los Alamos Meson Physics Facility

International Nuclear Information System (INIS)

Clearwater, S.H.; Papcun, G.; Clark, D.A.

1985-01-01

High energy particle experiments require an accelerator as a source of high energy particles. To increase the productivity of an accelerator facility, we wish to develop an expert system to control beam lines. Expert Systems are a branch of Artificial Intelligence where a computer program performs tasks requiring human expertise. Unlike most expert systems we have a physical model underlying our beam line and this model can be used with the expert system to improve performance. The development of the expert system will lead to an increased understanding of the beam line as well as the possibility of state-of-the-art expert system building

Moving along the Mental Number Line: Interactions between Whole-Body Motion and Numerical Cognition

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Hartmann, Matthias; Grabherr, Luzia; Mast, Fred W.

2012-01-01

Active head turns to the left and right have recently been shown to influence numerical cognition by shifting attention along the mental number line. In the present study, we found that passive whole-body motion influences numerical cognition. In a random-number generation task (Experiment 1), leftward and downward displacement of participants…

Microscope self-calibration based on micro laser line imaging and soft computing algorithms

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Apolinar Muñoz Rodríguez, J.

2018-06-01

A technique to perform microscope self-calibration via micro laser line and soft computing algorithms is presented. In this technique, the microscope vision parameters are computed by means of soft computing algorithms based on laser line projection. To implement the self-calibration, a microscope vision system is constructed by means of a CCD camera and a 38 μm laser line. From this arrangement, the microscope vision parameters are represented via Bezier approximation networks, which are accomplished through the laser line position. In this procedure, a genetic algorithm determines the microscope vision parameters by means of laser line imaging. Also, the approximation networks compute the three-dimensional vision by means of the laser line position. Additionally, the soft computing algorithms re-calibrate the vision parameters when the microscope vision system is modified during the vision task. The proposed self-calibration improves accuracy of the traditional microscope calibration, which is accomplished via external references to the microscope system. The capability of the self-calibration based on soft computing algorithms is determined by means of the calibration accuracy and the micro-scale measurement error. This contribution is corroborated by an evaluation based on the accuracy of the traditional microscope calibration.

Easy and difficult performance-approach goals : Their moderating effect on the link between task interest and performance attainment

NARCIS (Netherlands)

Blaga, Monica; Van Yperen, N.W.

2008-01-01

The purpose of this study was to demonstrate that the positive link between task interest and performance attainment can he negatively affected by the pursuit of difficult performance-approach goals. This was tested in a sample of 60 undergraduate Students at a Dutch university, In line with

Is a "Complex" Task Really Complex? Validating the Assumption of Cognitive Task Complexity

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Sasayama, Shoko

2016-01-01

In research on task-based learning and teaching, it has traditionally been assumed that differing degrees of cognitive task complexity can be inferred through task design and/or observations of differing qualities in linguistic production elicited by second language (L2) communication tasks. Without validating this assumption, however, it is…

Off-line concomitant release of dopamine and glutamate involvement in taste memory consolidation.

Science.gov (United States)

Guzmán-Ramos, Kioko; Osorio-Gómez, Daniel; Moreno-Castilla, Perla; Bermúdez-Rattoni, Federico

2010-07-01

It has been postulated that memory consolidation process requires post-learning molecular changes that will support long-term experiences. In the present study, we assessed with in vivo microdialysis and capillary electrophoresis whether such changes involve the release of neurotransmitters at post-acquisition stages. Using conditioned taste aversion paradigm we observed spontaneous off-line (i.e. in absence of stimulation) dopamine and glutamate reactivation within the insular cortex about 45 min after the stimuli association. These increments did not appear in control groups that were unable to acquire the task, and it seems to be dependent on amygdala activity since its reversible inactivation by tetrodotoxin impaired cortical off-line release of both neurotransmitters and memory consolidation. In addition, blockade of dopaminergic D1 and/or NMDA receptors before the off-line activity impaired long- but not short-term memory. These results suggest that off-line extracellular increments of glutamate and dopamine have a significant functional role in consolidation of taste memory.

On the importance of Task 1 and error performance measures in PRP dual-task studies

Directory of Open Access Journals (Sweden)

Tilo eStrobach

2015-04-01

Full Text Available The Psychological Refractory Period (PRP paradigm is a dominant research tool in the literature on dual-task performance. In this paradigm a first and second component task (i.e., Task 1 and 2 are presented with variable stimulus onset asynchronies (SOAs and priority to perform Task 1. The main indicator of dual-task impairment in PRP situations is an increasing Task 2-RT with decreasing SOAs. This impairment is typically explained with some task components being processed strictly sequentially in the context of the prominent central bottleneck theory. This assumption could implicitly suggest that processes of Task 1 are unaffected by Task 2 and bottleneck processing, i.e. decreasing SOAs do not increase RTs and error rates of the first task. The aim of the present review is to assess whether PRP dual-task studies included both RT and error data presentations and statistical analyses and whether studies including both data types (i.e., RTs and error rates show data consistent with this assumption (i.e., decreasing SOAs and unaffected RTs and/ or error rates in Task 1. This review demonstrates that, in contrast to RT presentations and analyses, error data is underrepresented in a substantial number of studies. Furthermore, a substantial number of studies with RT and error data showed a statistically significant impairment of Task 1 performance with decreasing SOA. Thus, these studies produced data that is not primarily consistent with the strong assumption that processes of Task 1 are unaffected by Task 2 and bottleneck processing in the context of PRP dual-task situations; this calls for a more careful report and analysis of Task 1 performance in PRP studies and for a more careful consideration of theories proposing additions to the bottleneck assumption, which are sufficiently general to explain Task 1 and Task 2 effects.

Effects of repetitive transcranial magnetic stimulation on arm function and decreasing unilateral spatial neglect in subacute stroke: a randomized controlled trial.

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Cha, Hyun Gyu; Kim, Myoung Kwon

2016-07-01

The objective of this study is to investigate the effect of repetitive transcranial magnetic stimulation (rTMS) on the functional recovery of stroke patients with unilateral neglect. Randomized controlled experimental study. Outpatient rehabilitation hospital. Thirty patients with stroke were randomly assigned to two groups: an rTMS group (experimental) and a control group. Stroke patients in the experimental group underwent comprehensive rehabilitation therapy and rTMS. Stroke patients in the control group underwent sham therapy and comprehensive rehabilitation therapy. Participants in both groups received therapy 5 days per week for 4 weeks. Line bisection, Albert, Box and block and Grip strength tests were assessed before and after the four-week therapy period. A significant difference in the post-training gains in Line bisection (16.53 SD 9.78 vs. 3.60 SD 5.02), Albert (14.13 SD 4.92 vs. 3.26 SD 2.01), Box and block (15.06 SD 9.68 vs. 6.93 SD 7.52), and Grip strength tests (3.60 SD 2.66 vs 0.80 SD 1.26) was observed between the experimental group and the control group (P<0.05). In addition, the effect size for gains in the experimental and control groups was very strong in AT, BBT (effect size=2.15, 0.77 respectively). We conclude that rTMS might be effective in improvement in reduction of the unilateral neglect and motor function. © The Author(s) 2015.

Influence of biases in numerical magnitude allocation on human prosocial decision making.

Science.gov (United States)

Arshad, Qadeer; Nigmatullina, Yuliya; Siddiqui, Shuaib; Franka, Mustafa; Mediratta, Saniya; Ramachandaran, Sanjeev; Lobo, Rhannon; Malhotra, Paresh A; Roberts, R E; Bronstein, Adolfo M

2017-12-01

Over the past decade neuroscientific research has attempted to probe the neurobiological underpinnings of human prosocial decision making. Such research has almost ubiquitously employed tasks such as the dictator game or similar variations (i.e., ultimatum game). Considering the explicit numerical nature of such tasks, it is surprising that the influence of numerical cognition on decision making during task performance remains unknown. While performing these tasks, participants typically tend to anchor on a 50:50 split that necessitates an explicit numerical judgement (i.e., number-pair bisection). Accordingly, we hypothesize that the decision-making process during the dictator game recruits overlapping cognitive processes to those known to be engaged during number-pair bisection. We observed that biases in numerical magnitude allocation correlated with the formulation of decisions during the dictator game. That is, intrinsic biases toward smaller numerical magnitudes were associated with the formulation of less favorable decisions, whereas biases toward larger magnitudes were associated with more favorable choices. We proceeded to corroborate this relationship by subliminally and systematically inducing biases in numerical magnitude toward either higher or lower numbers using a visuo-vestibular stimulation paradigm. Such subliminal alterations in numerical magnitude allocation led to proportional and corresponding changes to an individual's decision making during the dictator game. Critically, no relationship was observed between neither intrinsic nor induced biases in numerical magnitude on decision making when assessed using a nonnumerical-based prosocial questionnaire. Our findings demonstrate numerical influences on decisions formulated during the dictator game and highlight the necessity to control for confounds associated with numerical cognition in human decision-making paradigms. NEW & NOTEWORTHY We demonstrate that intrinsic biases in numerical magnitude

Service-provider and utility task-leadership integration. Paper D

International Nuclear Information System (INIS)

Bagshaw, S.; Van Tassell, D.

2011-01-01

As nuclear power utilities strive to stream-line their organizations, while improving outage and refurbishment project performance, the necessity for effective relationships and interaction between utility and service-providers becomes paramount. Successful integration of Service-Provider into the Utility's environment is achievable and has been demonstrated. Early and extensive engagement in front-end planning, single-point-of-continuity, and the use of integrated execution teams, are some of the critical elements for ensuring success. The paper discusses Task-Leadership Integration at the three levels of; utility executive level 'need-statement'; a 'why is this important' discussion; and as a 'thoughtful tutorial' on its features and practice. (author)

Cognitive task load analysis : Allocating tasks and designing support

NARCIS (Netherlands)

Neerincx, M.A.

2003-01-01

We present a method for Cognitive Task Analysis that guides the early stages of software development, aiming at an optimal cognitive load for operators of process control systems. The method is based on a practical theory of cognitive task load and support. In addition to the classical measure

THE RESPONSE OF TUNNEL LINING ON THERMAL LOADING

Directory of Open Access Journals (Sweden)

Markéta Levorová

2012-07-01

Full Text Available The long-term functionality, i.e. stability of the lining of disposal tunnels is a precondition for the safe removal and reprocessing of spent nuclear waste from deep underground repositories in the near or more distant future. The reason for removing containers with radioactive waste from such repositories lies in the potential development of presently unavailable “perfect” technology for its reprocessing. The stability problems of the tunnel lining exposed to the long-term thermal load generated by the waste in the disposal container was the subject of one task of the European TIMODAZ project (Thermal Impact on the Damaged Zone around a Radioactive Waste Disposal in Clay Host Rocks. Research was carried out by means of physical modeling. Although the project was terminated in September 2010, recorded data is being further analyzed. This paper describes the design, construction and results of an in-situ model which has been built at the Underground Research Centre Josef in the Czech Republic.

Overview of the ID, EPI and REL tasks of BioNLP Shared Task 2011

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Pyysalo Sampo

2012-06-01

Full Text Available Abstract We present the preparation, resources, results and analysis of three tasks of the BioNLP Shared Task 2011: the main tasks on Infectious Diseases (ID and Epigenetics and Post-translational Modifications (EPI, and the supporting task on Entity Relations (REL. The two main tasks represent extensions of the event extraction model introduced in the BioNLP Shared Task 2009 (ST'09 to two new areas of biomedical scientific literature, each motivated by the needs of specific biocuration tasks. The ID task concerns the molecular mechanisms of infection, virulence and resistance, focusing in particular on the functions of a class of signaling systems that are ubiquitous in bacteria. The EPI task is dedicated to the extraction of statements regarding chemical modifications of DNA and proteins, with particular emphasis on changes relating to the epigenetic control of gene expression. By contrast to these two application-oriented main tasks, the REL task seeks to support extraction in general by separating challenges relating to part-of relations into a subproblem that can be addressed by independent systems. Seven groups participated in each of the two main tasks and four groups in the supporting task. The participating systems indicated advances in the capability of event extraction methods and demonstrated generalization in many aspects: from abstracts to full texts, from previously considered subdomains to new ones, and from the ST'09 extraction targets to other entities and events. The highest performance achieved in the supporting task REL, 58% F-score, is broadly comparable with levels reported for other relation extraction tasks. For the ID task, the highest-performing system achieved 56% F-score, comparable to the state-of-the-art performance at the established ST'09 task. In the EPI task, the best result was 53% F-score for the full set of extraction targets and 69% F-score for a reduced set of core extraction targets, approaching a level

Action Intentions: Action Influences Both On-Line Perception and Off-Line Representation

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C Kirtley

2014-08-01

Full Text Available Given that one role of vision is to gather information for upcoming tasks, previous studies have investigated whether the preparation for action affects visual behaviour. The current studies aimed to determine if such influences on visual selection would also influence the formation of subsequent memory representations. Two experiments were conducted- in the first, participants' action intentions towards a scene were manipulated by the performance of different grasping postures as they observed the scene. This was followed by a memory test for the objects presented. Participants' eye movements were affected by their action intention, so that performing a power grip led to significantly longer fixation durations on power grip compatible objects. In contrast, memory for the objects and their properties was not affected by the action. Our second study required participants to make the action posture during the recall phase. No effect on eye movements was found, but recall was affected, with a particular advantage for recall of the position of grip-compatible objects. Previous studies have shown that action intentions can affect the on-line perception of objects. The current study suggests this may not extend to off-line representations if they are accessed after the action has been completed or abandoned. However, the recall of information may be affected if gestures are formed during retrieval. Memory representations may not be tailored specifically to an action, but actions can still affect the recall of information.

Two Dimensional Symmetric Correlation Functions of the S Operator and Two Dimensional Fourier Transforms: Considering the Line Coupling for P and R Lines of Linear Molecules

Science.gov (United States)

Ma, Q.; Boulet, C.; Tipping, R. H.

2014-01-01

The refinement of the Robert-Bonamy (RB) formalism by considering the line coupling for isotropic Raman Q lines of linear molecules developed in our previous study [Q. Ma, C. Boulet, and R. H. Tipping, J. Chem. Phys. 139, 034305 (2013)] has been extended to infrared P and R lines. In these calculations, the main task is to derive diagonal and off-diagonal matrix elements of the Liouville operator iS1 - S2 introduced in the formalism. When one considers the line coupling for isotropic Raman Q lines where their initial and final rotational quantum numbers are identical, the derivations of off-diagonal elements do not require extra correlation functions of the ^S operator and their Fourier transforms except for those used in deriving diagonal elements. In contrast, the derivations for infrared P and R lines become more difficult because they require a lot of new correlation functions and their Fourier transforms. By introducing two dimensional correlation functions labeled by two tensor ranks and making variable changes to become even functions, the derivations only require the latters' two dimensional Fourier transforms evaluated at two modulation frequencies characterizing the averaged energy gap and the frequency detuning between the two coupled transitions. With the coordinate representation, it is easy to accurately derive these two dimensional correlation functions. Meanwhile, by using the sampling theory one is able to effectively evaluate their two dimensional Fourier transforms. Thus, the obstacles in considering the line coupling for P and R lines have been overcome. Numerical calculations have been carried out for the half-widths of both the isotropic Raman Q lines and the infrared P and R lines of C2H2 broadened by N2. In comparison with values derived from the RB formalism, new calculated values are significantly reduced and become closer to measurements.

Mechanisms of Practice-Related Reductions of Dual-Task Interference with Simple Tasks: Data and Theory

Science.gov (United States)

Strobach, Tilo; Torsten, Schubert

2017-01-01

In dual-task situations, interference between two simultaneous tasks impairs performance. With practice, however, this impairment can be reduced. To identify mechanisms leading to a practice-related improvement in sensorimotor dual tasks, the present review applied the following general hypothesis: Sources that impair dual-task performance at the beginning of practice are associated with mechanisms for the reduction of dual-task impairment at the end of practice. The following types of processes provide sources for the occurrence of this impairment: (a) capacity-limited processes within the component tasks, such as response-selection or motor response stages, and (b) cognitive control processes independent of these tasks and thus operating outside of component-task performance. Dual-task practice studies show that, under very specific conditions, capacity-limited processes within the component tasks are automatized with practice, reducing the interference between two simultaneous tasks. Further, there is evidence that response-selection stages are shortened with practice. Thus, capacity limitations at these stages are sources for dual-task costs at the beginning of practice and are overcome with practice. However, there is no evidence demonstrating the existence of practice-related mechanisms associated with capacity-limited motor-response stages. Further, during practice, there is an acquisition of executive control skills for an improved allocation of limited attention resources to two tasks as well as some evidence supporting the assumption of improved task coordination. These latter mechanisms are associated with sources of dual-task interference operating outside of component task performance at the beginning of practice and also contribute to the reduction of dual-task interference at its end. PMID:28439319

On-line Social Interactions and Executive Functions

Directory of Open Access Journals (Sweden)

Oscar eYbarra

2012-04-01

Full Text Available A successful social interaction requires fast, on-line, and active construction of an ever-changing mental-model of another’s person beliefs, expectations, emotions, and desires. It also requires the ability to inhibit inappropriate behaviors, problem-solve, take-turns, and pursue goals in a distraction-rich environment. All these tasks rely on executive functions (EF—working memory, attention/cognitive control, and inhibition. Executive functioning has long been viewed as relatively static. However, starting with recent reports of successful cognitive interventions, this view is changing and now EFs are seen as much more open to both short and long term training, warm-up, and exhaustion effects. Some of the most intriguing evidence comes from research showing how social interaction enhances performance on standard EF tests. Interestingly, the latest research indicates these EF benefits are selectively conferred by certain on-line, dynamic social interactions, which require participants to engage with another person and actively construct the model of their mind. We review this literature and highlight its connection with evolutionary and cultural theories emphasizing links between intelligence and social life.

Self-Efficacy, Task Complexity and Task Performance: Exploring Interactions in Two Versions of Vocabulary Learning Tasks

Science.gov (United States)

Wu, Xiaoli; Lowyck, Joost; Sercu, Lies; Elen, Jan

2012-01-01

The present study aimed for better understanding of the interactions between task complexity and students' self-efficacy beliefs and students' use of learning strategies, and finally their interacting effects on task performance. This investigation was carried out in the context of Chinese students learning English as a foreign language in a…

The development of an expert system to tune a beam line

International Nuclear Information System (INIS)

Schultz, D.E.; Brown, P.A.; British Columbia Univ., Vancouver, BC

1989-01-01

The experience of developing an Expert System to aid in the tuning of the Ion Source Injection beam line at TRIUMF is described. The challenging and complex task of introducing Expert System technology into an established accelerator operation is outlined. Success in this environment depends strongly on the choice of project, the choice of experts, the choice of tools, and the methods used to represent the expertise. All these choices are discussed

AUTOMATED INSPECTION OF POWER LINE CORRIDORS TO MEASURE VEGETATION UNDERCUT USING UAV-BASED IMAGES

Directory of Open Access Journals (Sweden)

M. Maurer

2017-08-01

Full Text Available Power line corridor inspection is a time consuming task that is performed mostly manually. As the development of UAVs made huge progress in recent years, and photogrammetric computer vision systems became well established, it is time to further automate inspection tasks. In this paper we present an automated processing pipeline to inspect vegetation undercuts of power line corridors. For this, the area of inspection is reconstructed, geo-referenced, semantically segmented and inter class distance measurements are calculated. The presented pipeline performs an automated selection of the proper 3D reconstruction method for on the one hand wiry (power line, and on the other hand solid objects (surrounding. The automated selection is realized by performing pixel-wise semantic segmentation of the input images using a Fully Convolutional Neural Network. Due to the geo-referenced semantic 3D reconstructions a documentation of areas where maintenance work has to be performed is inherently included in the distance measurements and can be extracted easily. We evaluate the influence of the semantic segmentation according to the 3D reconstruction and show that the automated semantic separation in wiry and dense objects of the 3D reconstruction routine improves the quality of the vegetation undercut inspection. We show the generalization of the semantic segmentation to datasets acquired using different acquisition routines and to varied seasons in time.

Automated Inspection of Power Line Corridors to Measure Vegetation Undercut Using Uav-Based Images

Science.gov (United States)

Maurer, M.; Hofer, M.; Fraundorfer, F.; Bischof, H.

2017-08-01

Power line corridor inspection is a time consuming task that is performed mostly manually. As the development of UAVs made huge progress in recent years, and photogrammetric computer vision systems became well established, it is time to further automate inspection tasks. In this paper we present an automated processing pipeline to inspect vegetation undercuts of power line corridors. For this, the area of inspection is reconstructed, geo-referenced, semantically segmented and inter class distance measurements are calculated. The presented pipeline performs an automated selection of the proper 3D reconstruction method for on the one hand wiry (power line), and on the other hand solid objects (surrounding). The automated selection is realized by performing pixel-wise semantic segmentation of the input images using a Fully Convolutional Neural Network. Due to the geo-referenced semantic 3D reconstructions a documentation of areas where maintenance work has to be performed is inherently included in the distance measurements and can be extracted easily. We evaluate the influence of the semantic segmentation according to the 3D reconstruction and show that the automated semantic separation in wiry and dense objects of the 3D reconstruction routine improves the quality of the vegetation undercut inspection. We show the generalization of the semantic segmentation to datasets acquired using different acquisition routines and to varied seasons in time.

Effective task communication : the role of task information and the interpersonal teacher-student relationship.

NARCIS (Netherlands)

Broekkamp, H.; Dijk, van E.; Brekelmans, J.M.G.; Mainhard, T.; Brok, den P.J.

2009-01-01

Students who perceive assigned academic tasks as more clear perform better on these tasks. Moreover, it has been shown that "task clarity" (as experienced by students) varies across teachers. Apparently, some teachers are more effective than other teachers in communicating tasks. There is, however,

Technical errors in complete mouth radiographic survey according to radiographic techniques and film holding methods

International Nuclear Information System (INIS)

Choi, Karp Sik; Byun, Chong Soo; Choi, Soon Chul

1986-01-01

The purpose of this study was to investigate the numbers and causes of retakes in 300 complete mouth radiographic surveys made by 75 senior dental students. According to radiographic techniques and film holding methods, they were divided into 4 groups: Group I: Bisecting-angle technique with patient's fingers. Group II: Bisecting-angle technique with Rinn Snap-A-Ray device. Group III: Bisecting-angle technique with Rinn XCP instrument (short cone) Group IV: Bisecting-angle technique with Rinn XCP instrument (long cone). The most frequent cases of retakes, the most frequent tooth area examined, of retakes and average number of retakes per complete mouth survey were evaluated. The obtained results were as follows: Group I: Incorrect film placement (47.8), upper canine region, and 0.89. Group II: Incorrect film placement (44.0), upper canine region, and 1.12. Group III: Incorrect film placement (79.2), upper canine region, and 2.05. Group IV: Incorrect film placement (67.7), upper canine region, and 1.69.

Kokkos' Task DAG Capabilities.

Energy Technology Data Exchange (ETDEWEB)

Edwards, Harold C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ibanez, Daniel Alejandro [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-09-01

This report documents the ASC/ATDM Kokkos deliverable "Production Portable Dy- namic Task DAG Capability." This capability enables applications to create and execute a dynamic task DAG ; a collection of heterogeneous computational tasks with a directed acyclic graph (DAG) of "execute after" dependencies where tasks and their dependencies are dynamically created and destroyed as tasks execute. The Kokkos task scheduler executes the dynamic task DAG on the target execution resource; e.g. a multicore CPU, a manycore CPU such as Intel's Knights Landing (KNL), or an NVIDIA GPU. Several major technical challenges had to be addressed during development of Kokkos' Task DAG capability: (1) portability to a GPU with it's simplified hardware and micro- runtime, (2) thread-scalable memory allocation and deallocation from a bounded pool of memory, (3) thread-scalable scheduler for dynamic task DAG, (4) usability by applications.

Effects of age and type of picture on visuospatial working memory assessed with a computerized jigsaw-puzzle task.

Science.gov (United States)

Toril, Pilar; Reales, José M; Mayas, Julia; Ballesteros, Soledad

2017-09-15

We investigated the effect of age and color in a computerized version of the jigsaw-puzzle task. In Experiment 1, young and older adults were presented with puzzles in color and black-and-white line drawings, varying in difficulty from 4 to 9 pieces. Older adults performed the task better with the black-and-white stimuli and younger adults performed better with the color ones. In Experiment 2, new older and young adults identified the same fragmented pictures as fast and accurately as possible. The older group identified the black-and-white stimuli faster than those presented in color, while the younger adults identified both similarly. In Experiment 3A, new older and young groups performed the puzzle task with the same color pictures and their monochrome versions. In Experiment 3B, participants performed a speeded identification task with the two sets. The findings of these experiments showed that older adults have a memory not a perceptual difficulty.

Implicit and Explicit Knowledge Both Improve Dual Task Performance in a Continuous Pursuit Tracking Task.

Science.gov (United States)

Ewolds, Harald E; Bröker, Laura; de Oliveira, Rita F; Raab, Markus; Künzell, Stefan

2017-01-01

The goal of this study was to investigate the effect of predictability on dual-task performance in a continuous tracking task. Participants practiced either informed (explicit group) or uninformed (implicit group) about a repeated segment in the curves they had to track. In Experiment 1 participants practices the tracking task only, dual-task performance was assessed after by combining the tracking task with an auditory reaction time task. Results showed both groups learned equally well and tracking performance on a predictable segment in the dual-task condition was better than on random segments. However, reaction times did not benefit from a predictable tracking segment. To investigate the effect of learning under dual-task situation participants in Experiment 2 practiced the tracking task while simultaneously performing the auditory reaction time task. No learning of the repeated segment could be demonstrated for either group during the training blocks, in contrast to the test-block and retention test, where participants performed better on the repeated segment in both dual-task and single-task conditions. Only the explicit group improved from test-block to retention test. As in Experiment 1, reaction times while tracking a predictable segment were no better than reaction times while tracking a random segment. We concluded that predictability has a positive effect only on the predictable task itself possibly because of a task-shielding mechanism. For dual-task training there seems to be an initial negative effect of explicit instructions, possibly because of fatigue, but the advantage of explicit instructions was demonstrated in a retention test. This might be due to the explicit memory system informing or aiding the implicit memory system.

Status of the proton and electron transfer lines for the AWAKE Experiment at CERN

Energy Technology Data Exchange (ETDEWEB)

Schmidt, J.S., E-mail: janet.schmidt@cern.ch [CERN, Geneva (Switzerland); Bauche, J. [CERN, Geneva (Switzerland); Biskup, B. [CERN, Geneva (Switzerland); Czech Technical University, Prague (Czech Republic); Bracco, C.; Doebert, S.; Goddard, B.; Gschwendtner, E.; Jensen, L.K.; Jones, O.R.; Mazzoni, S.; Meddahi, M.; Pepitone, K.; Petrenko, A.; Velotti, F.M.; Vorozhtsov, A. [CERN, Geneva (Switzerland)

2016-09-01

The AWAKE project at CERN is planned to study proton driven plasma wakefield acceleration with an externally injected electron beam. Therefore two transfer lines are being designed in order to provide the proton beam from the SPS and the electron beam from an RF gun to the plasma cell. The commissioning of the proton line will take place in 2016 for the first phase of the experiment, which is focused on the self-modulation of a 12 cm long proton bunch in the plasma. The electron line will be added for the second phase of AWAKE in 2017, when the wakefield will be probed with an electron beam of 10–20 MeV/c. The challenge for these transfer lines lies in the parallel operation of the proton, electron and laser beam used to ionize the plasma and seed the self-modulation. These beams, of different characteristics, need to be synchronized and positioned for optimized injection conditions into the wakefield. This task requires great flexibility in the transfer line optics. The status of these designs will be presented in this paper.

Task Uncertainty Can Account for Mixing and Switch Costs in Task-Switching

Science.gov (United States)

Rennie, Jaime L.

2015-01-01

Cognitive control is required in situations that involve uncertainty or change, such as when resolving conflict, selecting responses and switching tasks. Recently, it has been suggested that cognitive control can be conceptualised as a mechanism which prioritises goal-relevant information to deal with uncertainty. This hypothesis has been supported using a paradigm that requires conflict resolution. In this study, we examine whether cognitive control during task switching is also consistent with this notion. We used information theory to quantify the level of uncertainty in different trial types during a cued task-switching paradigm. We test the hypothesis that differences in uncertainty between task repeat and task switch trials can account for typical behavioural effects in task-switching. Increasing uncertainty was associated with less efficient performance (i.e., slower and less accurate), particularly on switch trials and trials that afford little opportunity for advance preparation. Interestingly, both mixing and switch costs were associated with a common episodic control process. These results support the notion that cognitive control may be conceptualised as an information processor that serves to resolve uncertainty in the environment. PMID:26107646

Processes Adopted to Integrate Intangible Resources in Global Acquisitions among Container Lines: Perceptions of Acquirer and Acquired

Directory of Open Access Journals (Sweden)

Indika Sigera

2018-03-01

Full Text Available The spectrum of strategic co-operations among container lines varies from loose-knitted slot charters, liner conferences, shipping alliances, joint services and consortia, through to mergers and acquisitions (M&As. However, these forms of strategic co-operations have not always been able to achieve the intended synergetic growth resulting from the integration of resources. The Resource Based View (RBV suggests that integrating intangible resources, which are valuable, rare, inimitable and non-substitutable (VRIN, can make a significant contribution to the performance of post strategic co-operations. This research paper investigates the contribution of intangible resources to the post acquisition success six global acquisitions among container lines. The nine senior managers attached to global container lines were the main participants of this study. Five of them represented acquired container lines, four represented acquirer container lines. The paper explains their personnel experience on the processes adopts to integrate intangible resources in acquisitions. Keywords: Merger and Acquisitions, Intangible Resources, Container Lines, Task Integration, Human Integration

Performing maintenance activities on-line a risk perspective

International Nuclear Information System (INIS)

Darling, S.S.; Mairs, T.P.

1993-01-01

The US nuclear power industry is attempting to deal with the issue of optimizing the performance of maintenance activities with the advent of the maintenance rule. The impact of any maintenance activity on the safe operation of a nuclear power facility can be quantified on the basis of risk. Therefore, it is incumbent upon the industry to accommodate the regulator and present a maintenance optimization program in terms that explicitly address the potential risk inherent in its concept and implementation. The motivation for utilities to perform maintenance while the plant is operating (i.e., on-line) is readily perceived to offer the following advantages: 1. greater system availability; 2. higher plant capacity factor; 3. more evenly distributed workload for the maintenance department; and 4. overall safer plant operation. However, risks inherent in undertaking maintenance activities during power operation could amount to the realization that reapportionment of these tasks is not cost-beneficial. Therefore, it is important that any utility considering implementing such a paradigm in maintenance philosophy establish a rigorous process to select, perform, and monitor maintenance tasks performed while operating

Performance Enhancements Under Dual-task Conditions

Science.gov (United States)

Kramer, A. F.; Wickens, C. D.; Donchin, E.

1984-01-01

Research on dual-task performance has been concerned with delineating the antecedent conditions which lead to dual-task decrements. Capacity models of attention, which propose that a hypothetical resource structure underlies performance, have been employed as predictive devices. These models predict that tasks which require different processing resources can be more successfully time shared than tasks which require common resources. The conditions under which such dual-task integrality can be fostered were assessed in a study in which three factors likely to influence the integrality between tasks were manipulated: inter-task redundancy, the physical proximity of tasks and the task relevant objects. Twelve subjects participated in three experimental sessions in which they performed both single and dual-tasks. The primary task was a pursuit step tracking task. The secondary tasks required the discrimination between different intensities or different spatial positions of a stimulus. The results are discussed in terms of a model of dual-task integrality.

Task-relevant cognitive and motor functions are prioritized during prolonged speed-accuracy motor task performance.

Science.gov (United States)

Solianik, Rima; Satas, Andrius; Mickeviciene, Dalia; Cekanauskaite, Agne; Valanciene, Dovile; Majauskiene, Daiva; Skurvydas, Albertas

2018-06-01

This study aimed to explore the effect of prolonged speed-accuracy motor task on the indicators of psychological, cognitive, psychomotor and motor function. Ten young men aged 21.1 ± 1.0 years performed a fast- and accurate-reaching movement task and a control task. Both tasks were performed for 2 h. Despite decreased motivation, and increased perception of effort as well as subjective feeling of fatigue, speed-accuracy motor task performance improved during the whole period of task execution. After the motor task, the increased working memory function and prefrontal cortex oxygenation at rest and during conflict detection, and the decreased efficiency of incorrect response inhibition and visuomotor tracking were observed. The speed-accuracy motor task increased the amplitude of motor-evoked potentials, while grip strength was not affected. These findings demonstrate that to sustain the performance of 2-h speed-accuracy task under conditions of self-reported fatigue, task-relevant functions are maintained or even improved, whereas less critical functions are impaired.

Comparing Children's Performance on and Preference for a Number-Line Estimation Task: Tablet versus Paper and Pencil

Science.gov (United States)

Piatt, Carley; Coret, Marian; Choi, Michael; Volden, Joanne; Bisanz, Jeffrey

2016-01-01

Tablet computers (tablets) are positioned to be powerful, innovative, effective, and motivating research and assessment tools. We addressed two questions critical for evaluating the appropriateness of using tablets to study number-line estimation, a skill associated with math achievement and argued to be central to numerical cognition. First, is…

Cultural differences in on-line sensitivity to emotional voices: Comparing East and West

Directory of Open Access Journals (Sweden)

Pan eLiu

2015-05-01

Full Text Available Evidence that culture modulates on-line neural responses to the emotional meanings encoded by vocal and facial expressions was demonstrated recently in a study comparing English North Americans and Chinese (Liu et al., 2015. Here, we compared how individuals from these two cultures passively respond to emotional cues from faces and voices using an Oddball task. Participants viewed in-group emotional faces, with or without simultaneous vocal expressions, while performing a face-irrelevant visual task as the EEG was recorded. A significantly larger visual MMN was observed for Chinese versus English participants when faces were accompanied by voices, suggesting that Chinese were influenced to a larger extent by task-irrelevant vocal cues. These data highlight further differences in how adults from East Asian versus Western cultures process socio-emotional cues, arguing that distinct cultural practices in communication (e.g., display rules shape neurocognitive activity associated with the early perception and integration of multi-sensory emotional cues.

Task assignment and coaching

OpenAIRE

Dominguez-Martinez, S.

2009-01-01

An important task of a manager is to motivate her subordinates. One way in which a manager can give incentives to junior employees is through the assignment of tasks. How a manager allocates tasks in an organization, provides information to the junior employees about his ability. Without coaching from a manager, the junior employee only has information about his past performance. Based on his past performance, a talented junior who has performed a difficult task sometimes decides to leave the...

Functional Task Test (FTT)

Science.gov (United States)

Bloomberg, Jacob J.; Mulavara, Ajitkumar; Peters, Brian T.; Rescheke, Millard F.; Wood, Scott; Lawrence, Emily; Koffman, Igor; Ploutz-Snyder, Lori; Spiering, Barry A.; Feeback, Daniel L.;

Anterior medial prefrontal cortex exhibits activation during task preparation but deactivation during task execution.

Directory of Open Access Journals (Sweden)

Hideya Koshino

Full Text Available BACKGROUND: The anterior prefrontal cortex (PFC exhibits activation during some cognitive tasks, including episodic memory, reasoning, attention, multitasking, task sets, decision making, mentalizing, and processing of self-referenced information. However, the medial part of anterior PFC is part of the default mode network (DMN, which shows deactivation during various goal-directed cognitive tasks compared to a resting baseline. One possible factor for this pattern is that activity in the anterior medial PFC (MPFC is affected by dynamic allocation of attentional resources depending on task demands. We investigated this possibility using an event related fMRI with a face working memory task. METHODOLOGY/PRINCIPAL FINDINGS: Sixteen students participated in a single fMRI session. They were asked to form a task set to remember the faces (Face memory condition or to ignore them (No face memory condition, then they were given 6 seconds of preparation period before the onset of the face stimuli. During this 6-second period, four single digits were presented one at a time at the center of the display, and participants were asked to add them and to remember the final answer. When participants formed a task set to remember faces, the anterior MPFC exhibited activation during a task preparation period but deactivation during a task execution period within a single trial. CONCLUSIONS/SIGNIFICANCE: The results suggest that the anterior MPFC plays a role in task set formation but is not involved in execution of the face working memory task. Therefore, when attentional resources are allocated to other brain regions during task execution, the anterior MPFC shows deactivation. The results suggest that activation and deactivation in the anterior MPFC are affected by dynamic allocation of processing resources across different phases of processing.

The Effects of Multiple Exemplar Training on a Working Memory Task Involving Sequential Responding in Children with Autism

Science.gov (United States)

Baltruschat, Lisa; Hasselhorn, Marcus; Tarbox, Jonathan; Dixon, Dennis R.; Najdowski, Adel; Mullins, Ryan David; Gould, Evelyn

2012-01-01

This study is part of a programmatic line of research into the use of basic positive reinforcement procedures for improving working memory in children with autism spectrum disorders. The authors evaluated the effects of multiple exemplar training, utilizing positive reinforcement, on performance of a "digit span backwards" task--a test of working…

Prospective memory in young and older adults: the effects of task importance and ongoing task load.

Science.gov (United States)

Smith, Rebekah E; Hunt, R Reed

2014-01-01

Remembering to perform an action in the future, called prospective memory, often shows age-related differences in favor of young adults when tested in the laboratory. Recently Smith, Horn, and Bayen (2012; Aging, Neuropsychology, and Cognition, 19, 495) embedded a PM task in an ongoing color-matching task and manipulated the difficulty of the ongoing task by varying the number of colors on each trial of the task. Smith et al. found that age-related differences in PM performance (lower PM performance for older adults relative to young adults) persisted even when older adults could perform the ongoing task as well or better than the young adults. The current study investigates a possible explanation for the pattern of results reported by Smith et al. by including a manipulation of task emphasis: for half of the participants the prospective memory task was emphasize, while for the other half the ongoing color-matching task was emphasized. Older adults performed a 4-color version of the ongoing color-matching task, while young adults completed either the 4-color or a more difficult 6-color version of the ongoing task. Older adults failed to perform as well as the young adults on the prospective memory task regardless of task emphasis, even when older adults were performing as well or better than the young adults on the ongoing color-matching task. The current results indicate that the lack of an effect of ongoing task load on prospective memory task performance is not due to a perception that one or the other task is more important than the other.

Increased cognitive control after task conflict? Investigating the N-3 effect in task switching.

Science.gov (United States)

Schuch, Stefanie; Grange, James A

2018-05-25

Task inhibition is considered to facilitate switching to a new task and is assumed to decay slowly over time. Hence, more persisting inhibition needs to be overcome when returning to a task after one intermediary trial (ABA task sequence) than when returning after two or more intermediary trials (CBA task sequence). Schuch and Grange (J Exp Psychol Learn Mem Cogn 41:760-767, 2015) put forward the hypothesis that there is higher task conflict in ABA than CBA sequences, leading to increased cognitive control in the subsequent trial. They provided evidence that performance is better in trials following ABA than following CBA task sequences. Here, this effect of the previous task sequence ("N-3 effect") is further investigated by varying the cue-stimulus interval (CSI), allowing for short (100 ms) or long (900 ms) preparation time for the upcoming task. If increased cognitive control after ABA involves a better preparation for the upcoming task, the N-3 effect should be larger with long than short CSI. The results clearly show that this is not the case. In Experiment 1, the N-3 effect was smaller with long than short CSI; in Experiment 2, the N-3 effect was not affected by CSI. Diffusion model analysis confirmed previous results in the literature (regarding the effect of CSI and of the ABA-CBA difference); however, the N-3 effect was not unequivocally associated with any of the diffusion model parameters. In exploratory analysis, we also tested the alternative hypothesis that the N-3 effect involves more effective task shielding, which would be reflected in reduced congruency effects in trials following ABA, relative to trials following CBA; congruency effects did not differ between these conditions. Taken together, we can rule out two potential explanations of the N-3 effect: Neither is this effect due to enhanced task preparation, nor to more effective task shielding.

Service-provider and utility task-leadership integration. Paper D

Energy Technology Data Exchange (ETDEWEB)

Bagshaw, S.; Van Tassell, D. [AP Services, Inc., Freeport, PA (United States)

2011-07-01

As nuclear power utilities strive to stream-line their organizations, while improving outage and refurbishment project performance, the necessity for effective relationships and interaction between utility and service-providers becomes paramount. Successful integration of Service-Provider into the Utility's environment is achievable and has been demonstrated. Early and extensive engagement in front-end planning, single-point-of-continuity, and the use of integrated execution teams, are some of the critical elements for ensuring success. The paper discusses Task-Leadership Integration at the three levels of; utility executive level 'need-statement'; a 'why is this important' discussion; and as a 'thoughtful tutorial' on its features and practice. (author)

Spatial displacement of numbers on a vertical number line in spatial neglect

Directory of Open Access Journals (Sweden)

Urszula eMihulowicz

2015-04-01

Full Text Available Previous studies that investigated the association of numbers and space in humans came to contradictory conclusions about the spatial character of the mental number magnitude representation and about how it may be influenced by unilateral spatial neglect. The present study aimed to disentangle the debated influence of perceptual versus representational aspects via explicit mapping of numbers onto space by applying the number line estimation paradigm with vertical orientation of stimulus lines. Thirty-five acute right-brain damaged stroke patients (6 with neglect were asked to place two-digit numbers on vertically oriented lines with 0 marked at the bottom and 100 at the top. In contrast to the expected, nearly linear mapping in the control patient group, patients with spatial neglect overestimated the position of numbers in the lower middle range. The results corroborate spatial characteristics of the number magnitude representation. In neglect patients, this representation seems to be biased towards the ipsilesional side, independent of the physical orientation of the task stimuli.

Incidental orthographic learning during a color detection task.

Science.gov (United States)

Protopapas, Athanassios; Mitsi, Anna; Koustoumbardis, Miltiadis; Tsitsopoulou, Sofia M; Leventi, Marianna; Seitz, Aaron R

2017-09-01

Orthographic learning refers to the acquisition of knowledge about specific spelling patterns forming words and about general biases and constraints on letter sequences. It is thought to occur by strengthening simultaneously activated visual and phonological representations during reading. Here we demonstrate that a visual perceptual learning procedure that leaves no time for articulation can result in orthographic learning evidenced in improved reading and spelling performance. We employed task-irrelevant perceptual learning (TIPL), in which the stimuli to be learned are paired with an easy task target. Assorted line drawings and difficult-to-spell words were presented in red color among sequences of other black-colored words and images presented in rapid succession, constituting a fast-TIPL procedure with color detection being the explicit task. In five experiments, Greek children in Grades 4-5 showed increased recognition of words and images that had appeared in red, both during and after the training procedure, regardless of within-training testing, and also when targets appeared in blue instead of red. Significant transfer to reading and spelling emerged only after increased training intensity. In a sixth experiment, children in Grades 2-3 showed generalization to words not presented during training that carried the same derivational affixes as in the training set. We suggest that reinforcement signals related to detection of the target stimuli contribute to the strengthening of orthography-phonology connections beyond earlier levels of visually-based orthographic representation learning. These results highlight the potential of perceptual learning procedures for the reinforcement of higher-level orthographic representations. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Configuration Database for BaBar On-line

International Nuclear Information System (INIS)

Salnikov, Andrei

2003-01-01

The configuration database is one of the vital systems in the BaBar on-line system. It provides services for the different parts of the data acquisition system and control system, which require run-time parameters. The original design and implementation of the configuration database played a significant role in the successful BaBar operations since the beginning of experiment. Recent additions to the design of the configuration database provide better means for the management of data and add new tools to simplify main configuration tasks. We describe the design of the configuration database, its implementation with the Objectivity/DB object-oriented database, and our experience collected during the years of operation

Task assignment and coaching

NARCIS (Netherlands)

Dominguez-Martinez, S.

2009-01-01

An important task of a manager is to motivate her subordinates. One way in which a manager can give incentives to junior employees is through the assignment of tasks. How a manager allocates tasks in an organization, provides information to the junior employees about his ability. Without coaching

Blink activity and task difficulty.

Science.gov (United States)

Tanaka, Y; Yamaoka, K

1993-08-01

This study investigated the relationship between task difficulty and blink activity, which includes blink rate, blink amplitude, and blink duration. Two kinds of tasks established two levels of difficulty. In Exp. 1, a mental arithmetic task was used to examine the relationship. Analysis showed that blink rate for a difficult task was significantly higher than that for an easier one. In Exp. 2, a letter-search task (hiragana Japanese alphabet) was used while the other conditions were the same as those in Exp. 1; however, the results of this experiment were not influenced by the difficulty of the task. As results indicate that blink rate is related to not only difficulty but also the nature of the task, the nature of the task is probably dependent on a mechanism in information processing. The results for blink amplitude and blink duration showed no systematic change during either experiment.

Task uncertainty can account for mixing and switch costs in task-switching.

Directory of Open Access Journals (Sweden)

Patrick S Cooper

Full Text Available Cognitive control is required in situations that involve uncertainty or change, such as when resolving conflict, selecting responses and switching tasks. Recently, it has been suggested that cognitive control can be conceptualised as a mechanism which prioritises goal-relevant information to deal with uncertainty. This hypothesis has been supported using a paradigm that requires conflict resolution. In this study, we examine whether cognitive control during task switching is also consistent with this notion. We used information theory to quantify the level of uncertainty in different trial types during a cued task-switching paradigm. We test the hypothesis that differences in uncertainty between task repeat and task switch trials can account for typical behavioural effects in task-switching. Increasing uncertainty was associated with less efficient performance (i.e., slower and less accurate, particularly on switch trials and trials that afford little opportunity for advance preparation. Interestingly, both mixing and switch costs were associated with a common episodic control process. These results support the notion that cognitive control may be conceptualised as an information processor that serves to resolve uncertainty in the environment.

Preferential processing of task-irrelevant beloved-related information and task performance: Two event-related potential studies.

Science.gov (United States)

Langeslag, Sandra J E; van Strien, Jan W

2017-09-18

People who are in love have better attention for beloved-related information, but report having trouble focusing on other tasks, such as (home)work. So, romantic love can both improve and hurt cognition. Emotional information is preferentially processed, which improves task performance when the information is task-relevant, but hurts task performance when it is task-irrelevant. Because beloved-related information is highly emotional, the effects of romantic love on cognition may resemble these effects of emotion on cognition. We examined whether beloved-related information is preferentially processed even when it is task-irrelevant and whether this hurts task performance. In two event-related potential studies, participants who had recently fallen in love performed a visuospatial short-term memory task. Task-irrelevant beloved, friend, and stranger faces were presented during maintenance (Study 1), or encoding (Study 2). The Early Posterior Negativity (EPN) reflecting early automatic attentional capturing and the Late Positive Potential (LPP) reflecting sustained motivated attention were largest for beloved pictures. Thus, beloved pictures are preferentially processed even when they are task-irrelevant. Task performance and reaction times did not differ between beloved, friend, and stranger conditions. Nevertheless, self-reported obsessive thinking about the beloved tended to correlate negatively with task performance, and positively with reaction times, across conditions. So, although task-irrelevant beloved-related information does not impact task performance, more obsessive thinking about the beloved might relate to poorer and slower overall task performance. More research is needed to clarify why people experience trouble focusing on beloved-unrelated tasks and how this negative effect of love on cognition could be reduced. Copyright © 2017 Elsevier Ltd. All rights reserved.

Healthy older adults balance pattern under dual task conditions: exploring the strategy and trend

Directory of Open Access Journals (Sweden)

Bahareh Zeynalzadeh Ghoochani

2016-10-01

Full Text Available Background: In line with health promotion plans, early intervention and fall prevention in geriatric population, it is important to study healthy individuals balance mechanisms. The aim of this research was to investigate the effect of adding and removing visual input and dual task on elderly balance. Methods: Twenty healthy elderly recruited from four different senior citizen health club centers and from the University of Social Welfare and Rehabilitation Sciences (USWR participated in this analytic cross-sectional study. At USWR’s Motor Control Laboratory, the participants’ postural sway were assessed using force plate in 4 distinct double leg standing conditions with and without presence of visual input and Stroop dual task. Postural and Stroop variables were compared. Results: Findings indicated that when the elderly encountered with either dual task or absence of visual input, they can still manage the situation in a way that changes in sway parameter would not become significant. But, when these two conditions occurred simultaneously, the participant’s balance strategy fluctuated. Therefore, the mean velocity showed a significant difference between the "single quiet standing" condition and the condition of standing with eyes closed while the participants were answering Stroop dual task (Mean difference = -0.007, 95% CI = -0.012, -0.002. Conclusion: It appears that velocity parameter is sensitive to small changes, so it is recommended that researchers include this parameter in their future analyses. Balance in elderly can be manipulated by dual task and visual input deprivation.

Rules and more rules: the effects of multiple tasks, extensive training, and aging on task-switching performance.

Science.gov (United States)

Buchler, Norbou G; Hoyer, William J; Cerella, John

2008-06-01

Task-switching performance was assessed in young and older adults as a function of the number of task sets to be actively maintained in memory (varied from 1 to 4) over the course of extended training (5 days). Each of the four tasks required the execution of a simple computational algorithm, which was instantaneously cued by the color of the two-digit stimulus. Tasks were presented in pure (task set size 1) and mixed blocks (task set sizes 2, 3, 4), and the task sequence was unpredictable. By considering task switching beyond two tasks, we found evidence for a cognitive control system that is not overwhelmed by task set size load manipulations. Extended training eliminated age effects in task-switching performance, even when the participants had to manage the execution of up to four tasks. The results are discussed in terms of current theories of cognitive control, including task set inertia and production system postulates.

Task leaders reports

International Nuclear Information System (INIS)

Loriaux, E.F.; Jehee, J.N.T.

1995-01-01

Report on CRP-OSS Task 4.1.1. ''Survey of existing documentation relevant to this programme's goals'' and report on CRP-OSS Task 4.1.2. ''Survey of existing Operator Support Systems and the experience with them'' are presented. 2 tabs

Distraction during learning with hypermedia: Difficult tasks help to keep task goals on track

Directory of Open Access Journals (Sweden)

Katharina eScheiter

2014-03-01

Full Text Available In educational hypermedia environments, students are often confronted with potential sources of distraction arising from additional information that, albeit interesting, is unrelated to their current task goal. The paper investigates the conditions under which distraction occurs and hampers performance. Based on theories of volitional action control it was hypothesized that interesting information, especially if related to a pending goal, would interfere with task performance only when working on easy, but not on difficult tasks. In Experiment 1, 66 students learned about probability theory using worked examples and solved corresponding test problems, whose task difficulty was manipulated. As a second factor, the presence of interesting information unrelated to the primary task was varied. Results showed that students solved more easy than difficult probability problems correctly. However, the presence of interesting, but task-irrelevant information did not interfere with performance. In Experiment 2, 68 students again engaged in example-based learning and problem solving in the presence of task-irrelevant information. Problem-solving difficulty was varied as a first factor. Additionally, the presence of a pending goal related to the task-irrelevant information was manipulated. As expected, problem-solving performance declined when a pending goal was present during working on easy problems, whereas no interference was observed for difficult problems. Moreover, the presence of a pending goal reduced the time on task-relevant information and increased the time on task-irrelevant information while working on easy tasks. However, as revealed by mediation analyses these changes in overt information processing behavior did not explain the decline in problem-solving performance. As an alternative explanation it is suggested that goal conflicts resulting from pending goals claim cognitive resources, which are then no longer available for learning and

Spectral Bisection with Two Eigenvectors

Czech Academy of Sciences Publication Activity Database

Rocha, Israel

2017-01-01

Roč. 61, August (2017), s. 1019-1025 ISSN 1571-0653 Institutional support: RVO:67985807 Keywords : graph partitioning * Laplacian matrix * Fiedler vector Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics

The evaluation and quantification of respirable coal and silica dust concentrations: a task-based approach.

Science.gov (United States)

Grové, T; Van Dyk, T; Franken, A; Du Plessis, J

2014-01-01

Silicosis and coal worker's pneumoconiosis are serious occupational respiratory diseases associated with the coal mining industry and the inhalation of respirable dusts containing crystalline silica. The purpose of this study (funded by the Mine Health and Safety Council of South Africa) was to evaluate the individual contributions of underground coal mining tasks to the respirable dust and respirable silica dust concentrations in an underground section by sampling the respirable dust concentrations at the intake and return of each task. The identified tasks were continuous miner (CM) cutting, construction, transfer of coal, tipping, and roof bolting. The respirable dust-generating hierarchy of the tasks from highest to lowest was: transfer of coal > CM right cutting > CM left cutting > CM face cutting > construction > roof bolting > tipping; and for respirable silica dust: CM left cutting > construction > transfer of coal > CM right cutting. Personal exposure levels were determined by sampling the exposures of workers performing tasks in the section. Respirable dust concentrations and low concentrations of respirable silica dust were found at the intake air side of the section, indicating that air entering the section is already contaminated. The hierarchy for personal respirable dust exposures was as follows, from highest to lowest: CM operator > cable handler > miner > roof bolt operator > shuttle car operator, and for respirable silica dust: shuttle car operator > CM operator > cable handler > roof bolt operator > miner. Dust control methods to lower exposures should include revision of the position of workers with regard to the task performed, positioning of the tasks with regard to the CM cutting, and proper use of the line curtains to direct ventilation appropriately. The correct use of respiratory protection should also be encouraged.

The two-pore domain K+ channel TASK-1 is closely associated with brain barriers and meninges.

Science.gov (United States)

Kanjhan, Refik; Pow, David V; Noakes, Peter G; Bellingham, Mark C

2010-12-01

Impairment of the blood-brain barrier (BBB), the blood-cerebrospinal fluid (CSF) barrier and brain-CSF barrier has been implicated in neuropathology of several brain disorders, such as amyotrophic lateral sclerosis, cerebral edema, multiple sclerosis, neural inflammation, ischemia and stroke. Two-pore domain weakly inward rectifying K+ channel (TWIK)-related acid-sensitive potassium (TASK)-1 channels (K2p3.1; KCNK3) are among the targets that contribute to the development of these pathologies. For example TASK-1 activity is inhibited by acidification, ischemia, hypoxia and several signaling molecules released under pathologic conditions. We have used immuno-histochemistry to examine the distribution of the TASK-1 protein in structures associated with the BBB, blood-CSF barrier, brain-CSF barrier, and in the meninges of adult rat. Dense TASK-1 immuno-reactivity (TASK-1-IR) was observed in ependymal cells lining the fourth ventricle at the brain-CSF interface, in glial cells that ensheath the walls of blood vessels at the glio-vascular interface, and in the meninges. In these structures, TASK-1-IR often co-localized with glial fibrillary associated protein (GFAP) or vimentin. This study provides anatomical evidence for localization of TASK-1 K+ channels in cells that segregate distinct fluid compartments within and surrounding the brain. We suggest that TASK-1 channels, in coordination with other ion channels (e.g., aquaporins and chloride channels) and transporters (e.g., Na+-K+-ATPase and Na+-K+-2Cl⁻ and by virtue of its heterogeneous distribution, may differentially contribute to the varying levels of K+ vital for cellular function in these compartments. Our findings are likely to be relevant to recently reported roles of TASK-1 in cerebral ischemia, stroke and inflammatory brain disorders.

Single-Task and Dual-Task Gait Among Collegiate Athletes of Different Sport Classifications: Implications for Concussion Management.

Science.gov (United States)

Howell, David R; Oldham, Jessie R; DiFabio, Melissa; Vallabhajosula, Srikant; Hall, Eric E; Ketcham, Caroline J; Meehan, William P; Buckley, Thomas A

2017-02-01

Gait impairments have been documented following sport-related concussion. Whether preexisting gait pattern differences exist among athletes who participate in different sport classifications, however, remains unclear. Dual-task gait examinations probe the simultaneous performance of everyday tasks (ie, walking and thinking), and can quantify gait performance using inertial sensors. The purpose of this study was to compare the single-task and dual-task gait performance of collision/contact and noncontact athletes. A group of collegiate athletes (n = 265) were tested before their season at 3 institutions (mean age= 19.1 ± 1.1 years). All participants stood still (single-task standing) and walked while simultaneously completing a cognitive test (dual-task gait), and completed walking trials without the cognitive test (single-task gait). Spatial-temporal gait parameters were compared between collision/contact and noncontact athletes using MANCOVAs; cognitive task performance was compared using ANCOVAs. No significant single-task or dual-task gait differences were found between collision/contact and noncontact athletes. Noncontact athletes demonstrated higher cognitive task accuracy during single-task standing (P = .001) and dual-task gait conditions (P = .02) than collision/contact athletes. These data demonstrate the utility of a dual-task gait assessment outside of a laboratory and suggest that preinjury cognitive task performance during dual-tasks may differ between athletes of different sport classifications.

The relation between task characteristics, BI quality and task compatibility: An explorative study

DEFF Research Database (Denmark)

Gaardboe, Rikke; Jonasen, Tanja Svarre; Nyvang, Tom

2018-01-01

The purpose of this article is to investigate the relationship between task characteristics, business intelligence (BI) quality, and task compatibility. It is essential to investigate this relationship, as BI often builds up data from the organization's existing information systems, and thus......, is a supplement. In addition, there is a gap within existing research about task characteristics and BI. We conducted a survey of three companies, where 104 BI end users answered the questionnaire. Our findings reveal that BI users who experience high information quality solve difficult tasks, have a specified...

"Smart inhibition": electrophysiological evidence for the suppression of conflict-generating task rules during task switching.

Science.gov (United States)

Meiran, Nachshon; Hsieh, Shulan; Chang, Chi-Chih

2011-09-01

A major challenge for task switching is maintaining a balance between high task readiness and effectively ignoring irrelevant task rules. This calls for finely tuned inhibition that targets only the source of interference without adversely influencing other task-related representations. The authors show that irrelevant task rules generating response conflict are inhibited, causing their inefficient execution on the next trial (indicating the presence of competitor rule suppression[CRS];Meiran, Hsieh, & Dimov, Journal of Experimental Psychology: Learning, Memory and Cognition, 36, 992-1002, 2010). To determine whether CRS influences task rules, rather than target stimuli or responses, the authors focused on the processing of the task cue before the target stimulus was presented and before the response could be chosen. As was predicted, CRS was found in the event-related potentials in two time windows during task cue processing. It was also found in three time windows after target presentation. Source localization analyses suggest the involvement of the right dorsal prefrontal cortex in all five time windows.

Binding Task-Based Language Teaching and Task-Based Language Testing: A Survey into EFL Teachers and Learners' Views of Task-Based Approach

Science.gov (United States)

Panahi, Ali

2012-01-01

In most settings, task-based language teaching and testing have been dissociated from each other. That is why this study came to rethink of the learners' views towards awareness and implementation of task-based language teaching through IELTS listening tasks. To these objectives, after sketching instrumentation, the learners were divided into…

Advantages and disadvantages of intraoperative language tasks in awake surgery: a three-task approach for prefrontal tumors.

Science.gov (United States)

Rofes, A; Spena, G; Miozzo, A; Fontanella, M M; Miceli, G

2015-12-01

Multidisciplinary efforts are being made to provide surgical teams with sensitive and specific tasks for language mapping in awake surgery. Researchers and clinicians have elaborated different tasks over time. A fair amount of work has been directed to study the neurofunctional correlates of some of these tasks, and there is recent interest in their standardization. However, little discussion exists on the advantages and disadvantages that each task poses from the perspective of the cognitive neuroscience of language. Such an approach may be a relevant step to assess task validity, to avoid using tasks that tap onto similar processes, and to provide patients with a surgical treatment that ensures maximal tumor resection while avoiding postoperative language deficits. An understanding of the language components that each task entails may also be relevant to improve the current assessments and the ways in which tasks are administered, and to disentangle neurofunctional questions. We reviewed 17 language mapping tasks that have been used in awake surgery. Overt production tasks have been a preferred choice over comprehension tasks. Tasks tapping lexico-semantic processes, particularly object-naming, maintain their role as gold standards. Automated speech tasks are used to detect speech errors and to set the amplitude of the stimulator. Comprehension tasks, reading and writing tasks, and tasks that assess grammatical aspects of language may be regularly administered in the near future. We provide examples of a three-task approach we are administering to patients with prefrontal lesions. We believe that future advances in this area are contingent upon reviewing gold standards and introducing new assessment tools.

Simulating hemispatial neglect with virtual reality

Directory of Open Access Journals (Sweden)

Yoshizawa Makoto

2007-07-01

Full Text Available Abstract Background Hemispatial neglect is a cognitive disorder defined as a lack of attention for stimuli contra-lateral to the brain lesion. The assessment is traditionally done with basic pencil and paper tests and the rehabilitation programs are generally not well adapted. We propose a virtual reality system featuring an eye-tracking device for a better characterization of the neglect that will lead to new rehabilitation techniques. Methods This paper presents a comparison of eye-gaze patterns of healthy subjects, patients and healthy simulated patients on a virtual line bisection test. The task was also executed with a reduced visual field condition hoping that fewer stimuli would limit the neglect. Results We found that patients and healthy simulated patients had similar eye-gaze patterns. However, while the reduced visual field condition had no effect on the healthy simulated patients, it actually had a negative impact on the patients. We discuss the reasons for these differences and how they relate to the limitations of the neglect simulation. Conclusion We argue that with some improvements the technique could be used to determine the potential of new rehabilitation techniques and also help the rehabilitation staff or the patient's relatives to better understand the neglect condition.

Task Repetition Effects on L1 Use in EFL Child Task-Based Interaction

Science.gov (United States)

Azkarai, Agurtzane; García Mayo, María del Pilar

2017-01-01

Research has shown that tasks provide second language (L2) learners with many opportunities to learn the L2. Task repetition has been claimed to benefit L2 learning since familiarity with procedure and/or content gives learners the chance to focus on more specific aspects of language. Most research on task repetition has focused on adult…

Non-linear effects of transcranial direct current stimulation as a function of individual baseline performance: Evidence from biparietal tDCS influence on lateralized attention bias.

Science.gov (United States)

Benwell, Christopher S Y; Learmonth, Gemma; Miniussi, Carlo; Harvey, Monika; Thut, Gregor

2015-08-01

Transcranial direct current stimulation (tDCS) is a well-established technique for non-invasive brain stimulation (NIBS). However, the technique suffers from a high variability in outcome, some of which is likely explained by the state of the brain at tDCS-delivery but for which explanatory, mechanistic models are lacking. Here, we tested the effects of bi-parietal tDCS on perceptual line bisection as a function of tDCS current strength (1 mA vs 2 mA) and individual baseline discrimination sensitivity (a measure associated with intrinsic uncertainty/signal-to-noise balance). Our main findings were threefold. We replicated a previous finding (Giglia et al., 2011) of a rightward shift in subjective midpoint after Left anode/Right cathode tDCS over parietal cortex (sham-controlled). We found this effect to be weak over our entire sample (n = 38), but to be substantial in a subset of participants when they were split according to tDCS-intensity and baseline performance. This was due to a complex, nonlinear interaction between these two factors. Our data lend further support to the notion of state-dependency in NIBS which suggests outcome to depend on the endogenous balance between task-informative 'signal' and task-uninformative 'noise' at baseline. The results highlight the strong influence of individual differences and variations in experimental parameters on tDCS outcome, and the importance of fostering knowledge on the factors influencing tDCS outcome across cognitive domains. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Perception While Watching Movies: Effects of Physical Screen Size and Scene Type

Directory of Open Access Journals (Sweden)

Tom Troscianko

2012-08-01

Full Text Available Over the last decade, television screens and display monitors have increased in size considerably, but has this improved our televisual experience? Our working hypothesis was that the audiences adopt a general strategy that “bigger is better.” However, as our visual perceptions do not tap directly into basic retinal image properties such as retinal image size (C. A. Burbeck, 1987, we wondered whether object size itself might be an important factor. To test this, we needed a task that would tap into the subjective experiences of participants watching a movie on different-sized displays with the same retinal subtense. Our participants used a line bisection task to self-report their level of “presence” (i.e., their involvement with the movie at several target locations that were probed in a 45-min section of the movie “The Good, The Bad, and The Ugly.” Measures of pupil dilation and reaction time to the probes were also obtained. In Experiment 1, we found that subjective ratings of presence increased with physical screen size, supporting our hypothesis. Face scenes also produced higher presence scores than landscape scenes for both screen sizes. In Experiment 2, reaction time and pupil dilation results showed the same trends as the presence ratings and pupil dilation correlated with presence ratings, providing some validation of the method. Overall, the results suggest that real-time measures of subjective presence might be a valuable tool for measuring audience experience for different types of (i display and (ii audiovisual material.

Shaping pseudoneglect with transcranial cerebellar direct current stimulation and music listening

Directory of Open Access Journals (Sweden)

Silvia ePicazio

2015-03-01

Full Text Available Non-invasive brain stimulation modulates cortical excitability depending on the initial activation state of the structure being stimulated. Combination of cognitive with neurophysiological stimulations has been successfully employed to modulate responses of specific brain regions. The present research combined a neurophysiological pre-conditioning with a cognitive conditioning stimulation to modulate behavior. We applied this new state-dependency approach to investigate the cerebellar role in musical and spatial information processing, given that a link between musical perception and visuo-spatial abilities and a clear cerebellar involvement in music perception and visuo-spatial tasks have been reported. Cathodal, anodal or sham transcranial cerebellar Direct Current Stimulation (tcDCS pre-conditioning was applied on the left cerebellar hemisphere followed by conditioning stimulation through music or white noise listening in a sample of healthy subjects performing a Line Bisection Task (LBT. The combination of the cathodal stimulation with music listening resulted in a marked attentional shift toward the right hemispace, compensating thus the natural leftward bias of the baseline condition (pseudoneglect. Conversely, the anodal or sham pre-conditioning stimulations combined with either music and white noise conditioning listening did not modulate spatial attention. The efficacy of the combined stimulation (cathodal pre-conditioning and music conditioning and the absence of any effect of the single stimulations provide a strong support to the state-dependency theory. They propose that tcDCS in combination with music listening could act as a rehabilitative tool to improve cognitive functions in the presence of neglect or other spatial disorders.

Resource Allocation with the Use of the Balanced Scorecard and the Triple Bottom Line in Education

Science.gov (United States)

Nguyen, Chi Hong

2007-01-01

In terms of the economic bottom line, effective school leaders are now supposed to pay close attention to two central tasks which involve managing resources and devising operational strategies in their action plans. Taking a postmodern viewpoint, the first part of this paper aims to discuss the significance of resource allocation in education and…

Line facilities outline

International Nuclear Information System (INIS)

1998-08-01

This book deals with line facilities. The contents of this book are outline line of wire telecommunication ; development of line, classification of section of line and theory of transmission of line, cable line ; structure of line, line of cable in town, line out of town, domestic cable and other lines, Optical communication ; line of optical cable, transmission method, measurement of optical communication and cable of the sea bottom, Equipment of telecommunication line ; telecommunication line facilities and telecommunication of public works, construction of cable line and maintenance and Regulation of line equipment ; regulation on technique, construction and maintenance.

Angular quadrature sets for the streaming ray method in x-y geometry

International Nuclear Information System (INIS)

England, R.; Filippone, W.L.

1983-01-01

Steaming ray (SR) computations normally employ a set of specially selected ray directions. For x-y geometry, these directions are not uniformly spaced in the azimuthal angle, nor do they conform to any of the standard quadrature sets in current use. For simplicity in all previous SR computations, uniform angular weights were used. This note investigates two methods--a bisection scheme and a Fourier scheme--for selecting more appropriate azimuthal angular weights. In the bisection scheme, the azimuthal weight assigned to an SR direction is half the angular spread (in the x-y plane) between its two adjacent ray directions. In the Fourier method, the weights are chosen such that the number of terms in a Fourier series exactly integrable on the interval (0, 2π) is maximized. Several sample calculations have been performed. While both the Fourier and bisection weights showed significant advantage over the uniform weights used previously, the Fourier scheme appears to be the best method. Lists of bisection and Fourier weights are given for quadrature sets containing 4, 8, 12, ..., 60 azimuthal SR directions

Brain processing of task-relevant and task-irrelevant emotional words: an ERP study.

Science.gov (United States)

González-Villar, Alberto J; Triñanes, Yolanda; Zurrón, Montserrat; Carrillo-de-la-Peña, María T

2014-09-01

Although there is evidence for preferential perceptual processing of written emotional information, the effects of attentional manipulations and the time course of affective processing require further clarification. In this study, we attempted to investigate how the emotional content of words modulates cerebral functioning (event-related potentials, ERPs) and behavior (reaction times, RTs) when the content is task-irrelevant (emotional Stroop Task, EST) or task-relevant (emotional categorization task, ECT), in a sample of healthy middle-aged women. In the EST, the RTs were longer for emotional words than for neutral words, and in the ECT, they were longer for neutral and negative words than for positive words. A principal components analysis of the ERPs identified various temporospatial factors that were differentially modified by emotional content. P2 was the first emotion-sensitive component, with enhanced factor scores for negative nouns across tasks. The N2 and late positive complex had enhanced factor scores for emotional relative to neutral information only in the ECT. The results reinforce the idea that written emotional information has a preferential processing route, both when it is task-irrelevant (producing behavioral interference) and when it is task-relevant (facilitating the categorization). After early automatic processing of the emotional content, late ERPs become more emotionally modulated as the level of attention to the valence increases.

The United States pit disassembly and conversion project -- Meeting the MOX fuel specification

International Nuclear Information System (INIS)

Nelson, T.O.; James, C.A.; Kolman, D.G.

1998-01-01

The US is actively involved in demonstrating the disassembly of nuclear weapons pits to an unclassified form readied for disposition. The MOX option is the most likely path forward for plutonium that originated from nuclear weapon pits. The US demonstration line for pit disassembly and conversion is known as ARIES, the advanced recovery and integrated extraction system. The ARIES demonstration line is being used to gather data in an integrated fashion of the technologies needed for pit disassembly and conversion. These activities include the following modules: pit bisection, hydride-dehydride, oxide conversion, canning, electrolytic decontamination, and nondestructive assay (NDA). Pit bisection swages in a pit in half. Hydride-dehydride converts the pit plutonium metal to an unclassified metal button. To convert the plutonium metal to an oxide the US is investigating a number of options. The primary oxide conversion approach involves variations of combining plutonium hydriding and subsequent oxidation. Another approach is to simply oxidize the metal under controlled conditions-direct metal oxidation (DMO). To remove the gallium from the plutonium oxide, a thermal distillation approach is being used. These pyrochemical approaches will substantially reduce the wastes produced for oxide conversion of weapon plutonium, compared to traditional aqueous processing. The packaging of either the plutonium metal or oxide to long term storage criteria involves the canning and electrolytic decontamination modules. The NDA suite of instruments is then used to assay the material in the containers, which enables international verification without the need to open the containers and repackage them. All of these processes are described

Task-related modulation of visual neglect in cancellation tasks

OpenAIRE

Sarri, Margarita; Greenwood, Richard; Kalra, Lalit; Driver, Jon

2008-01-01

Unilateral neglect involves deficits of spatial exploration and awareness that do not always affect a fixed portion of extrapersonal space, but may vary with current stimulation and possibly with task demands. Here, we assessed any ‘top-down’, task-related influences on visual neglect, with novel experimental variants of the cancellation test. Many different versions of the cancellation test are used clinically, and can differ in the extent of neglect revealed, though the exact factors determ...

Is Performance in Task-Cuing Experiments Mediated by Task Set Selection or Associative Compound Retrieval?

Science.gov (United States)

Forrest, Charlotte L. D.; Monsell, Stephen; McLaren, Ian P. L.

2014-01-01

Task-cuing experiments are usually intended to explore control of task set. But when small stimulus sets are used, they plausibly afford learning of the response associated with a combination of cue and stimulus, without reference to tasks. In 3 experiments we presented the typical trials of a task-cuing experiment: a cue (colored shape) followed,…

Dividing attention between tasks : Testing whether explicit payoff functions elicit optimal dual-task performance

NARCIS (Netherlands)

Farmer, George D.; Janssen, C.P.|info:eu-repo/dai/nl/412781654; Nguyen, Anh T; Brumby, Duncan P.

2018-01-01

We test people's ability to optimize performance across two concurrent tasks. Participants performed a number entry task while controlling a randomly moving cursor with a joystick. Participants received explicit feedback on their performance on these tasks in the form of a single combined score.

Physical Education-in-CLIL tasks. Determining tasks characteristics through the analysis of the diaries

Directory of Open Access Journals (Sweden)

Josep Coral Mateu

2013-07-01

Full Text Available This article focuses on the characteristics of Physical Education-in-CLIL (PE-in-CLIL tasks. CLIL (Content and Language Integrated Learning is a teaching approach which uses foreign language as a tool to enhance the subject learning process. We connect PE-in-CLIL with key competences and we introduce the CLIL 4Cs framework. We establish the aims of the study, that is; to describe the features of tasks which are most suitable to PE-in-CLIL and identify integrated tasks which appeal most to learners. We use Action-Research and we collect data through diaries. The participants of the study were twenty-six learners of 5th grade of primary school. We described the strategies of rigour and quality applied and we analysed data using a qualitative data analysis software programme (NVivo. In the results, we identify both the tasks that appeal to students and the tasks that are developed successfully. In the conclusions, we provide teaching guidelines to plan successful PE-in-CLIL tasks that appeal to students. At this point, we emphasise tasks that combined both cooperative learning and oracy with motor activity and games. We also declare the necessity of incorporating scaffolding strategies in order to accommodate students’ linguistic needs and facilitate tasks development. Future CLIL research possibilities emerge in the Physical Education field of work.

On-line maintenance at Cofrentes NPP

International Nuclear Information System (INIS)

Roldan Vilches, J.; Moreno Matarranz, M. A.; Hermana Mendioroz, I.

1998-01-01

Cofrentes NPP has begun in 1997 activities related to At Power Preventive Maintenance over trains or systems which lead to a voluntary entry in a Limitative Condition of Operation (LCO) of the Technical Specifications. From others benefits, this program ha improved the risk management and the staff's knowledge over the functions and safety implications of the different systems, the better exploit of the resources, the co-ordination of the different organisations involved (Maintenance an Operation) and the reductions of works during shutdowns. Previous to each work, a feasibility study analyzes qualitative and quantitative (PSA), using the Risk Monitor, the implications on safety of all the tasks, assuring that the global safety of the Plant is always maintained. Tech. Spec. are analyzed in detail and also are analyzed situations of simultaneous unavailabilities of systems which could lead to a high risk situation. Two different risk controls are defined (punctual and accumulated) to assure that high risk situations will not be given. Finally, historical risk profile is analyzed to assure that the accumulated risk increase is not significant. Risk Monitor helps staff in the schedule and follow-up of the activities of On-Line Maintenance. Each one of the tasks are deeply planned and harshly analyzed and are carried out by high qualified workers. By the moment, this program is running with fully satisfaction on the Plant. (Author)

Achievement report on the research on possibility of expanding application of information technology to automobile production line; Jidosha seisan kotei eno joho tsushin gijutsu tekiyo kakudai kanosei ni kansuru chosa kenkyu

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

Before submitting propositions on important technological tasks to be generated in the automobile production line upon application of IT (information technology), a questionnairing is implemented to know the actualities of the line for the purpose of planning a proper merger of IT and the manufacturing technology development capability of the IT accepting site. The questionnaire, aiming at the embodiment of the goals of the projects 'IT related technical tasks relative to its helping human creation of new technologies and enhancement of human ability to make improvement' and 'Technical tasks of developing technical skills into technologies,' asks engineers about the actualities of knowhow at automobile production lines and its development into technologies, about how they take care of what they learned from their predecessors, and about their expectations from and views and opinions toward IT introduction and utilization. It is important to efficiently utilize IT as a means to solve problems involving the knowhow related training on the production line and the handing down of the acquired knowhow to the juniors. Since individual workers' knowhow assumes a certain role at each stage of the automobile production line and since it is necessary to extract the maximum from each worker and to utilize the fruit for improvement on productivity and work efficiency, it is indispensable to efficiently merge the knowhow with IT. (NEDO)

Succumbing to Bottom-Up Biases on Task Choice Predicts Increased Switch Costs in the Voluntary Task Switching Paradigm

Science.gov (United States)

Orr, Joseph M.; Weissman, Daniel H.

2010-01-01

Bottom-up biases are widely thought to influence task choice in the voluntary task switching paradigm. Definitive support for this hypothesis is lacking, however, because task choice and task performance are usually confounded. We therefore revisited this hypothesis using a paradigm in which task choice and task performance are temporally separated. As predicted, participants tended to choose the task that was primed by bottom-up biases. Moreover, such choices were linked to increased switch costs during subsequent task performance. These findings provide compelling evidence that bottom-up biases influence voluntary task choice. They also suggest that succumbing to such biases reflects a reduction of top-down control that persists to influence upcoming task performance. PMID:21713192

Dual-Task Walking in Challenging Environments in People with Stroke: Cognitive-Motor Interference and Task Prioritization

Directory of Open Access Journals (Sweden)

Celine Timmermans

2018-01-01

Full Text Available Cognitive-motor interference may contribute to the risk of falling in people with stroke, as may be the associated phenomenon of inappropriate task prioritization. Examining dual-task walking could provide valuable insights as to how to best evaluate and treat walking in people with stroke. This study aimed to examine the effect of different walking environments on cognitive-motor interference and task prioritization in dual-task walking in people with stroke. Using a repeated-measures design, cognitive-motor interference and task prioritization were assessed in 30 stroke survivors, while walking in a plain environment and in two challenging environments that were enriched with either stationary physical context or suddenly appearing projector-augmented context. All three walking environment conditions were performed with and without a concurrent serial-3 subtraction task. We found stronger cognitive-motor interference for the two challenging environments than for the plain walking environment. Cognitive-motor interference did not differ between challenging walking environments, but task prioritization did: motor performance was prioritized more in the environment with physical context than in the environment with projector-augmented context and vice versa for cognitive-task performance. In conclusion, walking environment strongly influenced cognitive-motor interference and task prioritization during dual-task walking in people with stroke.

Cultural differences in on-line sensitivity to emotional voices: comparing East and West

OpenAIRE

Liu, Pan; Rigoulot, Simon; Pell, Marc D.

2015-01-01

Evidence that culture modulates on-line neural responses to the emotional meanings encoded by vocal and facial expressions was demonstrated recently in a study comparing English North Americans and Chinese (Liu et al., 2015). Here, we compared how individuals from these two cultures passively respond to emotional cues from faces and voices using an Oddball task. Participants viewed in-group emotional faces, with or without simultaneous vocal expressions, while performing a face-irrelevant vis...

Task Selection, Task Switching and Multitasking during Computer-Based Independent Study

Science.gov (United States)

Judd, Terry

2015-01-01

Detailed logs of students' computer use, during independent study sessions, were captured in an open-access computer laboratory. Each log consisted of a chronological sequence of tasks representing either the application or the Internet domain displayed in the workstation's active window. Each task was classified using a three-tier schema…

Similarity law for Widom lines and coexistence lines.

Science.gov (United States)

Banuti, D T; Raju, M; Ihme, M

2017-05-01

The coexistence line of a fluid separates liquid and gaseous states at subcritical pressures, ending at the critical point. Only recently, it became clear that the supercritical state space can likewise be divided into regions with liquidlike and gaslike properties, separated by an extension to the coexistence line. This crossover line is commonly referred to as the Widom line, and is characterized by large changes in density or enthalpy, manifesting as maxima in the thermodynamic response functions. Thus, a reliable representation of the coexistence line and the Widom line is important for sub- and supercritical applications that depend on an accurate prediction of fluid properties. While it is known for subcritical pressures that nondimensionalization with the respective species critical pressures p_{cr} and temperatures T_{cr} only collapses coexistence line data for simple fluids, this approach is used for Widom lines of all fluids. However, we show here that the Widom line does not adhere to the corresponding states principle, but instead to the extended corresponding states principle. We resolve this problem in two steps. First, we propose a Widom line functional based on the Clapeyron equation and derive an analytical, species specific expression for the only parameter from the Soave-Redlich-Kwong equation of state. This parameter is a function of the acentric factor ω and compares well with experimental data. Second, we introduce the scaled reduced pressure p_{r}^{*} to replace the previously used reduced pressure p_{r}=p/p_{cr}. We show that p_{r}^{*} is a function of the acentric factor only and can thus be readily determined from fluid property tables. It collapses both subcritical coexistence line and supercritical Widom line data over a wide range of species with acentric factors ranging from -0.38 (helium) to 0.34 (water), including alkanes up to n-hexane. By using p_{r}^{*}, the extended corresponding states principle can be applied within

Changes in corticospinal excitability during consolidation predict acute exercise-induced off-line gains in procedural memory

DEFF Research Database (Denmark)

Ostadan, Fatemeh; Centeno, Carla; Daloze, Jean-Felix

2016-01-01

A single bout of cardiovascular exercise performed immediately after practicing a motor task improves the long-term retention of the skill through an optimization of memory consolidation. However, the specific brain mechanisms underlying the effects of acute cardiovascular exercise on procedural...... exercise correlated with the magnitude of off-line gains in skill level assessed in a retention test performed 8h after motor practice. A single bout of exercise modulates short-term neuroplasticity mechanisms subserving consolidation processes that predict off-line gains in procedural memory....... memory are poorly understood. We sought to determine if a single bout of exercise modifies corticospinal excitability (CSE) during the early stages of memory consolidation. In addition, we investigated if changes in CSE are associated with exercise-induced off-line gains in procedural memory...

Dynamic, continuous multitasking training leads to task-specific improvements but does not transfer across action selection tasks

Science.gov (United States)

Bender, Angela D.; Filmer, Hannah L.; Naughtin, Claire K.; Dux, Paul E.

2017-12-01

The ability to perform multiple tasks concurrently is an ever-increasing requirement in our information-rich world. Despite this, multitasking typically compromises performance due to the processing limitations associated with cognitive control and decision-making. While intensive dual-task training is known to improve multitasking performance, only limited evidence suggests that training-related performance benefits can transfer to untrained tasks that share overlapping processes. In the real world, however, coordinating and selecting several responses within close temporal proximity will often occur in high-interference environments. Over the last decade, there have been notable reports that training on video action games that require dynamic multitasking in a demanding environment can lead to transfer effects on aspects of cognition such as attention and working memory. Here, we asked whether continuous and dynamic multitasking training extends benefits to tasks that are theoretically related to the trained tasks. To examine this issue, we asked a group of participants to train on a combined continuous visuomotor tracking task and a perceptual discrimination task for six sessions, while an active control group practiced the component tasks in isolation. A battery of tests measuring response selection, response inhibition, and spatial attention was administered before and immediately after training to investigate transfer. Multitasking training resulted in substantial, task-specific gains in dual-task ability, but there was no evidence that these benefits generalized to other action control tasks. The findings suggest that training on a combined visuomotor tracking and discrimination task results in task-specific benefits but provides no additional value for untrained action selection tasks.

Performing Task Integration

DEFF Research Database (Denmark)

Elkjaer, Bente; Nickelsen, Niels Christian Mossfeldt

by shared goals and knowledge as well as mutual respect and frequent, timely, accurate and problem-solving ways of communication with the purpose of dealing with the tasks at hand in an integrated way. We introduce and discuss relational coordination theory through a case-study within public healthcare....... Here cross-professional coordination of work was done by scheduled communication twice a day. When we proposed a way for further integration of tasks through an all-inclusive team organization, we were met with resistance. We use the study to discuss whether relational coordination theory is able to do...... away with differences regarding task definitions and working conditions as well as professional knowledge hierarchies and responsibilities for parts and wholes....

Impact of task design on task performance and injury risk: case study of a simulated drilling task.

Science.gov (United States)

Alabdulkarim, Saad; Nussbaum, Maury A; Rashedi, Ehsan; Kim, Sunwook; Agnew, Michael; Gardner, Richard

2017-06-01

Existing evidence is limited regarding the influence of task design on performance and ergonomic risk, or the association between these two outcomes. In a controlled experiment, we constructed a mock fuselage to simulate a drilling task common in aircraft manufacturing, and examined the effect of three levels of workstation adjustability on performance as measured by productivity (e.g. fuselage completion time) and quality (e.g. fuselage defective holes), and ergonomic risk as quantified using two common methods (rapid upper limb assessment and the strain index). The primary finding was that both productivity and quality significantly improved with increased adjustability, yet this occurred only when that adjustability succeeded in reducing ergonomic risk. Supporting the inverse association between ergonomic risk and performance, the condition with highest adjustability created the lowest ergonomic risk and the best performance while there was not a substantial difference in ergonomic risk between the other two conditions, in which performance was also comparable. Practitioner Summary: Findings of this study supported a causal relationship between task design and both ergonomic risk and performance, and that ergonomic risk and performance are inversely associated. While future work is needed under more realistic conditions and a broader population, these results may be useful for task (re)design and to help cost-justify some ergonomic interventions.

Testing Anchoring effect in CV Data from Dichotomous Choice with a Follow-up Questioning

Energy Technology Data Exchange (ETDEWEB)

Shin, Young Cheol [Dae-Jin University, Pocheon (Korea)

1998-09-01

A questionnaire of dual bisected selection of CVM, which is an induced approach of intended payment, was suggested to overcome statistical inefficiency of a questionnaire of single bisected selection. In spite of several advantages of it, it is doubted that there would be an occurrence of anchoring effect, which is a psychological source of convenient starting point. Therefore, the general intended payment model, which can review the anchoring effect from CV questionnaire of dual bisected selection, was suggested and a mechanism that can review the anchoring effect from the model. This model is combining the dual variation model by Cameron and Quiggin (1994) with the results of bisected selective responses of a firstly presented particular amount as an explanatory variable of the second interior intended payment amount. If the sign of coefficient of the results of bisected selective responses of a firstly presented particular amount was negative and statistically significant, then it can be said that there is an anchoring effect. However, when there is uncertainty of occurrence of anchoring effect from the coefficient review, there is no need to worry about the anchoring effect if the average of estimated values of intended payment amount from two responses were different. As a result of applying this model and mechanism to CV materials on the improvement of water quality of the Han River, there is no need to worry about the anchoring effect. (author). 21 refs., 4 tabs.

Efficient task assignment in spatial crowdsourcing with worker and task privacy protection

KAUST Repository

Liu, An

2017-08-01

Spatial crowdsourcing (SC) outsources tasks to a set of workers who are required to physically move to specified locations and accomplish tasks. Recently, it is emerging as a promising tool for emergency management, as it enables efficient and cost-effective collection of critical information in emergency such as earthquakes, when search and rescue survivors in potential ares are required. However in current SC systems, task locations and worker locations are all exposed in public without any privacy protection. SC systems if attacked thus have penitential risk of privacy leakage. In this paper, we propose a protocol for protecting the privacy for both workers and task requesters while maintaining the functionality of SC systems. The proposed protocol is built on partially homomorphic encryption schemes, and can efficiently realize complex operations required during task assignment over encrypted data through a well-designed computation strategy. We prove that the proposed protocol is privacy-preserving against semi-honest adversaries. Simulation on two real-world datasets shows that the proposed protocol is more effective than existing solutions and can achieve mutual privacy-preserving with acceptable computation and communication cost.

Are factors related to dual-task performance in people with Parkinson's disease dependent on the type of dual task?

Science.gov (United States)

Strouwen, Carolien; Molenaar, Esther A L M; Keus, Samyra H J; Münks, Liesbeth; Heremans, Elke; Vandenberghe, Wim; Bloem, Bastiaan R; Nieuwboer, Alice

2016-02-01

Impaired dual-task performance significantly impacts upon functional mobility in people with Parkinson's disease (PD). The aim of this study was to identify determinants of dual-task performance in people with PD in three different dual tasks to assess their possible task-dependency. We recruited 121 home-dwelling patients with PD (mean age 65.93 years; mean disease duration 8.67 years) whom we subjected to regular walking (control condition) and to three dual-task conditions: walking combined with a backwards Digit Span task, an auditory Stroop task and a Mobile Phone task. We measured dual-task gait velocity using the GAITRite mat and dual-task reaction times and errors on the concurrent tasks as outcomes. Motor, cognitive and descriptive variables which correlated to dual-task performance (p task gait velocity and executive function, tested by the alternating intake test, was significantly associated with gait velocity during the Digit Span (R(2) = 0.65; p task (R(2) = 0.62; p task. Age was a surplus determinant of gait velocity while using a mobile phone. Single-task gait velocity and executive function as measured by a verbal fluency switching task were independent determinants of dual-task gait performance in people with PD. In contrast to expectation, these factors were the same across different tasks, supporting the robustness of the findings. Future study needs to determine whether these factors predict dual-task abnormalities prospectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Efficient task assignment in spatial crowdsourcing with worker and task privacy protection

KAUST Repository

Liu, An; Wang, Weiqi; Shang, Shuo; Li, Qing; Zhang, Xiangliang

2017-01-01

Spatial crowdsourcing (SC) outsources tasks to a set of workers who are required to physically move to specified locations and accomplish tasks. Recently, it is emerging as a promising tool for emergency management, as it enables efficient and cost

vi and Vim Editors Pocket Reference Support for every text editing task

CERN Document Server

Robbins, Arnold

2011-01-01

Many Unix, Linux, and Mac OS X geeks enjoy using the powerful, platform-agnostic text editors vi and Vim, but there are far too many commands for anyone to remember. Author Arnold Robbins has chosen the most valuable commands for vi, Vim, and vi's main clones-vile, elvis, and nvi-and packed them into this easy-to-browse pocket reference. You'll find commands for all kinds of editing tasks, such as programming, modifying system files, and writing and marking up articles. This second edition includes: Command-line optionsvi commands and set optionsInput mode shortcutsSubstitution and regular e

Iowa Gambling Task with non-clinical participants: Effects of using real + virtual cards and additional trials

Directory of Open Access Journals (Sweden)

William H Overman

2013-12-01

Full Text Available Performance on the Iowa Gambling Task (IGT in clinical populations can be interpreted only in relation to established base line performance in normal populations. As in all comparisons of assessment tools, the normal base line must reflect performance under conditions in which subjects can function at their best levels. In this review, we show that a number of variables enhance IGT performance in non-clinical participants. First, optimal performance is produced by having participants turn over real cards while viewing virtual cards on a computer screen. The use of only virtual cards results in significantly lower performance than the combination of real + virtual cards. Secondly, administration of more than 100 trials also enhances performance. When using the real/virtual card procedure, performance is shown to significantly increase from early adolescence through young adulthood. Under these conditions young (mean age 19 years and older (mean age 59 years adults perform equally. Females, as a group, score lower than males because females tend to choose cards from high-frequency-of-gain Deck B. Groups of females with high or low gonadal hormones perform equally. Concurrent tasks, e.g., presentation of aromas, decrease performance in males. Age and gender effects are discussed in terms of a dynamic between testosterone and orbital prefrontal cortex.

Experience with an on-line computer for controlling and optimizing the gas supply and the application of various peak-load supply plants of a public utility

Energy Technology Data Exchange (ETDEWEB)

Poll, J [Technische Werke der Stadt Stuttgart A.G. (Germany, F.R.)

1977-02-01

The computer system has the following tasks: 1) On-line control; 2) supply of an information system; 3) performance of a gas marketing forecast; 4) background computations. Measured data are compiled, processed, monitored, recorded, prepared, and stored. The process is controlled by about a dozen programmes, the remaining tasks are taken over by 22 programmes. The system has proved a success.

Task-dependent changes of corticospinal excitability during observation and motor imagery of balance tasks.

Science.gov (United States)

Mouthon, A; Ruffieux, J; Wälchli, M; Keller, M; Taube, W

2015-09-10

Non-physical balance training has demonstrated to be efficient to improve postural control in young people. However, little is known about the potential to increase corticospinal excitability by mental simulation in lower leg muscles. Mental simulation of isolated, voluntary contractions of limb muscles increase corticospinal excitability but more automated tasks like walking seem to have no or only minor effects on motor-evoked potentials (MEPs) evoked by transcranial magnetic stimulation (TMS). This may be related to the way of performing the mental simulation or the task itself. Therefore, the present study aimed to clarify how corticospinal excitability is modulated during AO+MI, MI and action observation (AO) of balance tasks. For this purpose, MEPs and H-reflexes were elicited during three different mental simulations (a) AO+MI, (b) MI and (c) passive AO. For each condition, two balance tasks were evaluated: (1) quiet upright stance (static) and (2) compensating a medio-lateral perturbation while standing on a free-swinging platform (dynamic). AO+MI resulted in the largest facilitation of MEPs followed by MI and passive AO. MEP facilitation was significantly larger in the dynamic perturbation than in the static standing task. Interestingly, passive observation resulted in hardly any facilitation independent of the task. H-reflex amplitudes were not modulated. The current results demonstrate that corticospinal excitability during mental simulation of balance tasks is influenced by both the type of mental simulation and the task difficulty. As H-reflexes and background EMG were not modulated, it may be argued that changes in excitability of the primary motor cortex were responsible for the MEP modulation. From a functional point of view, our findings suggest best training/rehabilitation effects when combining MI with AO during challenging postural tasks. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

The development of a task analysis method applicable to the tasks of nuclear power plant